From: Aaron Tomlin Date: Tue, 22 Mar 2022 14:03:31 +0000 (+0000) Subject: module: Move all into module/ X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=cfc1d277891eb499b3b5354df33b30f598683e90;p=linux.git module: Move all into module/ No functional changes. This patch moves all module related code into a separate directory, modifies each file name and creates a new Makefile. Note: this effort is in preparation to refactor core module code. Reviewed-by: Christophe Leroy Signed-off-by: Aaron Tomlin Signed-off-by: Luis Chamberlain --- diff --git a/MAINTAINERS b/MAINTAINERS index fd768d43e0482..5e7778cd437f9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13264,7 +13264,7 @@ L: linux-kernel@vger.kernel.org S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git modules-next F: include/linux/module.h -F: kernel/module.c +F: kernel/module/ MONOLITHIC POWER SYSTEM PMIC DRIVER M: Saravanan Sekar diff --git a/kernel/Makefile b/kernel/Makefile index 471d71935e90a..a7f8c088cc945 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -29,7 +29,6 @@ KCOV_INSTRUMENT_softirq.o := n KCSAN_SANITIZE_softirq.o = n # These are called from save_stack_trace() on slub debug path, # and produce insane amounts of uninteresting coverage. -KCOV_INSTRUMENT_module.o := n KCOV_INSTRUMENT_extable.o := n KCOV_INSTRUMENT_stacktrace.o := n # Don't self-instrument. @@ -53,6 +52,7 @@ obj-y += rcu/ obj-y += livepatch/ obj-y += dma/ obj-y += entry/ +obj-$(CONFIG_MODULES) += module/ obj-$(CONFIG_KCMP) += kcmp.o obj-$(CONFIG_FREEZER) += freezer.o @@ -66,9 +66,6 @@ ifneq ($(CONFIG_SMP),y) obj-y += up.o endif obj-$(CONFIG_UID16) += uid16.o -obj-$(CONFIG_MODULES) += module.o -obj-$(CONFIG_MODULE_DECOMPRESS) += module_decompress.o -obj-$(CONFIG_MODULE_SIG) += module_signing.o obj-$(CONFIG_MODULE_SIG_FORMAT) += module_signature.o obj-$(CONFIG_KALLSYMS) += kallsyms.o obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o diff --git a/kernel/module-internal.h b/kernel/module-internal.h deleted file mode 100644 index 8c381c99062f2..0000000000000 --- a/kernel/module-internal.h +++ /dev/null @@ -1,50 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* Module internals - * - * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - */ - -#include -#include - -struct load_info { - const char *name; - /* pointer to module in temporary copy, freed at end of load_module() */ - struct module *mod; - Elf_Ehdr *hdr; - unsigned long len; - Elf_Shdr *sechdrs; - char *secstrings, *strtab; - unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs; - struct _ddebug *debug; - unsigned int num_debug; - bool sig_ok; -#ifdef CONFIG_KALLSYMS - unsigned long mod_kallsyms_init_off; -#endif -#ifdef CONFIG_MODULE_DECOMPRESS - struct page **pages; - unsigned int max_pages; - unsigned int used_pages; -#endif - struct { - unsigned int sym, str, mod, vers, info, pcpu; - } index; -}; - -extern int mod_verify_sig(const void *mod, struct load_info *info); - -#ifdef CONFIG_MODULE_DECOMPRESS -int module_decompress(struct load_info *info, const void *buf, size_t size); -void module_decompress_cleanup(struct load_info *info); -#else -static inline int module_decompress(struct load_info *info, - const void *buf, size_t size) -{ - return -EOPNOTSUPP; -} -static inline void module_decompress_cleanup(struct load_info *info) -{ -} -#endif diff --git a/kernel/module.c b/kernel/module.c deleted file mode 100644 index 6cea788fd965c..0000000000000 --- a/kernel/module.c +++ /dev/null @@ -1,4810 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright (C) 2002 Richard Henderson - * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. - */ - -#define INCLUDE_VERMAGIC - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "module-internal.h" - -#define CREATE_TRACE_POINTS -#include - -#ifndef ARCH_SHF_SMALL -#define ARCH_SHF_SMALL 0 -#endif - -/* - * Modules' sections will be aligned on page boundaries - * to ensure complete separation of code and data, but - * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y - */ -#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX -# define debug_align(X) ALIGN(X, PAGE_SIZE) -#else -# define debug_align(X) (X) -#endif - -/* If this is set, the section belongs in the init part of the module */ -#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) - -/* - * Mutex protects: - * 1) List of modules (also safely readable with preempt_disable), - * 2) module_use links, - * 3) module_addr_min/module_addr_max. - * (delete and add uses RCU list operations). - */ -static DEFINE_MUTEX(module_mutex); -static LIST_HEAD(modules); - -/* Work queue for freeing init sections in success case */ -static void do_free_init(struct work_struct *w); -static DECLARE_WORK(init_free_wq, do_free_init); -static LLIST_HEAD(init_free_list); - -#ifdef CONFIG_MODULES_TREE_LOOKUP - -/* - * Use a latched RB-tree for __module_address(); this allows us to use - * RCU-sched lookups of the address from any context. - * - * This is conditional on PERF_EVENTS || TRACING because those can really hit - * __module_address() hard by doing a lot of stack unwinding; potentially from - * NMI context. - */ - -static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) -{ - struct module_layout *layout = container_of(n, struct module_layout, mtn.node); - - return (unsigned long)layout->base; -} - -static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) -{ - struct module_layout *layout = container_of(n, struct module_layout, mtn.node); - - return (unsigned long)layout->size; -} - -static __always_inline bool -mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) -{ - return __mod_tree_val(a) < __mod_tree_val(b); -} - -static __always_inline int -mod_tree_comp(void *key, struct latch_tree_node *n) -{ - unsigned long val = (unsigned long)key; - unsigned long start, end; - - start = __mod_tree_val(n); - if (val < start) - return -1; - - end = start + __mod_tree_size(n); - if (val >= end) - return 1; - - return 0; -} - -static const struct latch_tree_ops mod_tree_ops = { - .less = mod_tree_less, - .comp = mod_tree_comp, -}; - -static struct mod_tree_root { - struct latch_tree_root root; - unsigned long addr_min; - unsigned long addr_max; -} mod_tree __cacheline_aligned = { - .addr_min = -1UL, -}; - -#define module_addr_min mod_tree.addr_min -#define module_addr_max mod_tree.addr_max - -static noinline void __mod_tree_insert(struct mod_tree_node *node) -{ - latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); -} - -static void __mod_tree_remove(struct mod_tree_node *node) -{ - latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); -} - -/* - * These modifications: insert, remove_init and remove; are serialized by the - * module_mutex. - */ -static void mod_tree_insert(struct module *mod) -{ - mod->core_layout.mtn.mod = mod; - mod->init_layout.mtn.mod = mod; - - __mod_tree_insert(&mod->core_layout.mtn); - if (mod->init_layout.size) - __mod_tree_insert(&mod->init_layout.mtn); -} - -static void mod_tree_remove_init(struct module *mod) -{ - if (mod->init_layout.size) - __mod_tree_remove(&mod->init_layout.mtn); -} - -static void mod_tree_remove(struct module *mod) -{ - __mod_tree_remove(&mod->core_layout.mtn); - mod_tree_remove_init(mod); -} - -static struct module *mod_find(unsigned long addr) -{ - struct latch_tree_node *ltn; - - ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); - if (!ltn) - return NULL; - - return container_of(ltn, struct mod_tree_node, node)->mod; -} - -#else /* MODULES_TREE_LOOKUP */ - -static unsigned long module_addr_min = -1UL, module_addr_max = 0; - -static void mod_tree_insert(struct module *mod) { } -static void mod_tree_remove_init(struct module *mod) { } -static void mod_tree_remove(struct module *mod) { } - -static struct module *mod_find(unsigned long addr) -{ - struct module *mod; - - list_for_each_entry_rcu(mod, &modules, list, - lockdep_is_held(&module_mutex)) { - if (within_module(addr, mod)) - return mod; - } - - return NULL; -} - -#endif /* MODULES_TREE_LOOKUP */ - -/* - * Bounds of module text, for speeding up __module_address. - * Protected by module_mutex. - */ -static void __mod_update_bounds(void *base, unsigned int size) -{ - unsigned long min = (unsigned long)base; - unsigned long max = min + size; - - if (min < module_addr_min) - module_addr_min = min; - if (max > module_addr_max) - module_addr_max = max; -} - -static void mod_update_bounds(struct module *mod) -{ - __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); - if (mod->init_layout.size) - __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); -} - -#ifdef CONFIG_KGDB_KDB -struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ -#endif /* CONFIG_KGDB_KDB */ - -static void module_assert_mutex_or_preempt(void) -{ -#ifdef CONFIG_LOCKDEP - if (unlikely(!debug_locks)) - return; - - WARN_ON_ONCE(!rcu_read_lock_sched_held() && - !lockdep_is_held(&module_mutex)); -#endif -} - -#ifdef CONFIG_MODULE_SIG -static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); -module_param(sig_enforce, bool_enable_only, 0644); - -void set_module_sig_enforced(void) -{ - sig_enforce = true; -} -#else -#define sig_enforce false -#endif - -/* - * Export sig_enforce kernel cmdline parameter to allow other subsystems rely - * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. - */ -bool is_module_sig_enforced(void) -{ - return sig_enforce; -} -EXPORT_SYMBOL(is_module_sig_enforced); - -/* Block module loading/unloading? */ -int modules_disabled = 0; -core_param(nomodule, modules_disabled, bint, 0); - -/* Waiting for a module to finish initializing? */ -static DECLARE_WAIT_QUEUE_HEAD(module_wq); - -static BLOCKING_NOTIFIER_HEAD(module_notify_list); - -int register_module_notifier(struct notifier_block *nb) -{ - return blocking_notifier_chain_register(&module_notify_list, nb); -} -EXPORT_SYMBOL(register_module_notifier); - -int unregister_module_notifier(struct notifier_block *nb) -{ - return blocking_notifier_chain_unregister(&module_notify_list, nb); -} -EXPORT_SYMBOL(unregister_module_notifier); - -/* - * We require a truly strong try_module_get(): 0 means success. - * Otherwise an error is returned due to ongoing or failed - * initialization etc. - */ -static inline int strong_try_module_get(struct module *mod) -{ - BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); - if (mod && mod->state == MODULE_STATE_COMING) - return -EBUSY; - if (try_module_get(mod)) - return 0; - else - return -ENOENT; -} - -static inline void add_taint_module(struct module *mod, unsigned flag, - enum lockdep_ok lockdep_ok) -{ - add_taint(flag, lockdep_ok); - set_bit(flag, &mod->taints); -} - -/* - * A thread that wants to hold a reference to a module only while it - * is running can call this to safely exit. - */ -void __noreturn __module_put_and_kthread_exit(struct module *mod, long code) -{ - module_put(mod); - kthread_exit(code); -} -EXPORT_SYMBOL(__module_put_and_kthread_exit); - -/* Find a module section: 0 means not found. */ -static unsigned int find_sec(const struct load_info *info, const char *name) -{ - unsigned int i; - - for (i = 1; i < info->hdr->e_shnum; i++) { - Elf_Shdr *shdr = &info->sechdrs[i]; - /* Alloc bit cleared means "ignore it." */ - if ((shdr->sh_flags & SHF_ALLOC) - && strcmp(info->secstrings + shdr->sh_name, name) == 0) - return i; - } - return 0; -} - -/* Find a module section, or NULL. */ -static void *section_addr(const struct load_info *info, const char *name) -{ - /* Section 0 has sh_addr 0. */ - return (void *)info->sechdrs[find_sec(info, name)].sh_addr; -} - -/* Find a module section, or NULL. Fill in number of "objects" in section. */ -static void *section_objs(const struct load_info *info, - const char *name, - size_t object_size, - unsigned int *num) -{ - unsigned int sec = find_sec(info, name); - - /* Section 0 has sh_addr 0 and sh_size 0. */ - *num = info->sechdrs[sec].sh_size / object_size; - return (void *)info->sechdrs[sec].sh_addr; -} - -/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */ -static unsigned int find_any_sec(const struct load_info *info, const char *name) -{ - unsigned int i; - - for (i = 1; i < info->hdr->e_shnum; i++) { - Elf_Shdr *shdr = &info->sechdrs[i]; - if (strcmp(info->secstrings + shdr->sh_name, name) == 0) - return i; - } - return 0; -} - -/* - * Find a module section, or NULL. Fill in number of "objects" in section. - * Ignores SHF_ALLOC flag. - */ -static __maybe_unused void *any_section_objs(const struct load_info *info, - const char *name, - size_t object_size, - unsigned int *num) -{ - unsigned int sec = find_any_sec(info, name); - - /* Section 0 has sh_addr 0 and sh_size 0. */ - *num = info->sechdrs[sec].sh_size / object_size; - return (void *)info->sechdrs[sec].sh_addr; -} - -/* Provided by the linker */ -extern const struct kernel_symbol __start___ksymtab[]; -extern const struct kernel_symbol __stop___ksymtab[]; -extern const struct kernel_symbol __start___ksymtab_gpl[]; -extern const struct kernel_symbol __stop___ksymtab_gpl[]; -extern const s32 __start___kcrctab[]; -extern const s32 __start___kcrctab_gpl[]; - -#ifndef CONFIG_MODVERSIONS -#define symversion(base, idx) NULL -#else -#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) -#endif - -struct symsearch { - const struct kernel_symbol *start, *stop; - const s32 *crcs; - enum mod_license { - NOT_GPL_ONLY, - GPL_ONLY, - } license; -}; - -struct find_symbol_arg { - /* Input */ - const char *name; - bool gplok; - bool warn; - - /* Output */ - struct module *owner; - const s32 *crc; - const struct kernel_symbol *sym; - enum mod_license license; -}; - -static bool check_exported_symbol(const struct symsearch *syms, - struct module *owner, - unsigned int symnum, void *data) -{ - struct find_symbol_arg *fsa = data; - - if (!fsa->gplok && syms->license == GPL_ONLY) - return false; - fsa->owner = owner; - fsa->crc = symversion(syms->crcs, symnum); - fsa->sym = &syms->start[symnum]; - fsa->license = syms->license; - return true; -} - -static unsigned long kernel_symbol_value(const struct kernel_symbol *sym) -{ -#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS - return (unsigned long)offset_to_ptr(&sym->value_offset); -#else - return sym->value; -#endif -} - -static const char *kernel_symbol_name(const struct kernel_symbol *sym) -{ -#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS - return offset_to_ptr(&sym->name_offset); -#else - return sym->name; -#endif -} - -static const char *kernel_symbol_namespace(const struct kernel_symbol *sym) -{ -#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS - if (!sym->namespace_offset) - return NULL; - return offset_to_ptr(&sym->namespace_offset); -#else - return sym->namespace; -#endif -} - -static int cmp_name(const void *name, const void *sym) -{ - return strcmp(name, kernel_symbol_name(sym)); -} - -static bool find_exported_symbol_in_section(const struct symsearch *syms, - struct module *owner, - void *data) -{ - struct find_symbol_arg *fsa = data; - struct kernel_symbol *sym; - - sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, - sizeof(struct kernel_symbol), cmp_name); - - if (sym != NULL && check_exported_symbol(syms, owner, - sym - syms->start, data)) - return true; - - return false; -} - -/* - * Find an exported symbol and return it, along with, (optional) crc and - * (optional) module which owns it. Needs preempt disabled or module_mutex. - */ -static bool find_symbol(struct find_symbol_arg *fsa) -{ - static const struct symsearch arr[] = { - { __start___ksymtab, __stop___ksymtab, __start___kcrctab, - NOT_GPL_ONLY }, - { __start___ksymtab_gpl, __stop___ksymtab_gpl, - __start___kcrctab_gpl, - GPL_ONLY }, - }; - struct module *mod; - unsigned int i; - - module_assert_mutex_or_preempt(); - - for (i = 0; i < ARRAY_SIZE(arr); i++) - if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) - return true; - - list_for_each_entry_rcu(mod, &modules, list, - lockdep_is_held(&module_mutex)) { - struct symsearch arr[] = { - { mod->syms, mod->syms + mod->num_syms, mod->crcs, - NOT_GPL_ONLY }, - { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, - mod->gpl_crcs, - GPL_ONLY }, - }; - - if (mod->state == MODULE_STATE_UNFORMED) - continue; - - for (i = 0; i < ARRAY_SIZE(arr); i++) - if (find_exported_symbol_in_section(&arr[i], mod, fsa)) - return true; - } - - pr_debug("Failed to find symbol %s\n", fsa->name); - return false; -} - -/* - * Search for module by name: must hold module_mutex (or preempt disabled - * for read-only access). - */ -static struct module *find_module_all(const char *name, size_t len, - bool even_unformed) -{ - struct module *mod; - - module_assert_mutex_or_preempt(); - - list_for_each_entry_rcu(mod, &modules, list, - lockdep_is_held(&module_mutex)) { - if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) - continue; - if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) - return mod; - } - return NULL; -} - -struct module *find_module(const char *name) -{ - return find_module_all(name, strlen(name), false); -} - -#ifdef CONFIG_SMP - -static inline void __percpu *mod_percpu(struct module *mod) -{ - return mod->percpu; -} - -static int percpu_modalloc(struct module *mod, struct load_info *info) -{ - Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; - unsigned long align = pcpusec->sh_addralign; - - if (!pcpusec->sh_size) - return 0; - - if (align > PAGE_SIZE) { - pr_warn("%s: per-cpu alignment %li > %li\n", - mod->name, align, PAGE_SIZE); - align = PAGE_SIZE; - } - - mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); - if (!mod->percpu) { - pr_warn("%s: Could not allocate %lu bytes percpu data\n", - mod->name, (unsigned long)pcpusec->sh_size); - return -ENOMEM; - } - mod->percpu_size = pcpusec->sh_size; - return 0; -} - -static void percpu_modfree(struct module *mod) -{ - free_percpu(mod->percpu); -} - -static unsigned int find_pcpusec(struct load_info *info) -{ - return find_sec(info, ".data..percpu"); -} - -static void percpu_modcopy(struct module *mod, - const void *from, unsigned long size) -{ - int cpu; - - for_each_possible_cpu(cpu) - memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); -} - -bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) -{ - struct module *mod; - unsigned int cpu; - - preempt_disable(); - - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (!mod->percpu_size) - continue; - for_each_possible_cpu(cpu) { - void *start = per_cpu_ptr(mod->percpu, cpu); - void *va = (void *)addr; - - if (va >= start && va < start + mod->percpu_size) { - if (can_addr) { - *can_addr = (unsigned long) (va - start); - *can_addr += (unsigned long) - per_cpu_ptr(mod->percpu, - get_boot_cpu_id()); - } - preempt_enable(); - return true; - } - } - } - - preempt_enable(); - return false; -} - -/** - * is_module_percpu_address() - test whether address is from module static percpu - * @addr: address to test - * - * Test whether @addr belongs to module static percpu area. - * - * Return: %true if @addr is from module static percpu area - */ -bool is_module_percpu_address(unsigned long addr) -{ - return __is_module_percpu_address(addr, NULL); -} - -#else /* ... !CONFIG_SMP */ - -static inline void __percpu *mod_percpu(struct module *mod) -{ - return NULL; -} -static int percpu_modalloc(struct module *mod, struct load_info *info) -{ - /* UP modules shouldn't have this section: ENOMEM isn't quite right */ - if (info->sechdrs[info->index.pcpu].sh_size != 0) - return -ENOMEM; - return 0; -} -static inline void percpu_modfree(struct module *mod) -{ -} -static unsigned int find_pcpusec(struct load_info *info) -{ - return 0; -} -static inline void percpu_modcopy(struct module *mod, - const void *from, unsigned long size) -{ - /* pcpusec should be 0, and size of that section should be 0. */ - BUG_ON(size != 0); -} -bool is_module_percpu_address(unsigned long addr) -{ - return false; -} - -bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) -{ - return false; -} - -#endif /* CONFIG_SMP */ - -#define MODINFO_ATTR(field) \ -static void setup_modinfo_##field(struct module *mod, const char *s) \ -{ \ - mod->field = kstrdup(s, GFP_KERNEL); \ -} \ -static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ - struct module_kobject *mk, char *buffer) \ -{ \ - return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ -} \ -static int modinfo_##field##_exists(struct module *mod) \ -{ \ - return mod->field != NULL; \ -} \ -static void free_modinfo_##field(struct module *mod) \ -{ \ - kfree(mod->field); \ - mod->field = NULL; \ -} \ -static struct module_attribute modinfo_##field = { \ - .attr = { .name = __stringify(field), .mode = 0444 }, \ - .show = show_modinfo_##field, \ - .setup = setup_modinfo_##field, \ - .test = modinfo_##field##_exists, \ - .free = free_modinfo_##field, \ -}; - -MODINFO_ATTR(version); -MODINFO_ATTR(srcversion); - -static char last_unloaded_module[MODULE_NAME_LEN+1]; - -#ifdef CONFIG_MODULE_UNLOAD - -EXPORT_TRACEPOINT_SYMBOL(module_get); - -/* MODULE_REF_BASE is the base reference count by kmodule loader. */ -#define MODULE_REF_BASE 1 - -/* Init the unload section of the module. */ -static int module_unload_init(struct module *mod) -{ - /* - * Initialize reference counter to MODULE_REF_BASE. - * refcnt == 0 means module is going. - */ - atomic_set(&mod->refcnt, MODULE_REF_BASE); - - INIT_LIST_HEAD(&mod->source_list); - INIT_LIST_HEAD(&mod->target_list); - - /* Hold reference count during initialization. */ - atomic_inc(&mod->refcnt); - - return 0; -} - -/* Does a already use b? */ -static int already_uses(struct module *a, struct module *b) -{ - struct module_use *use; - - list_for_each_entry(use, &b->source_list, source_list) { - if (use->source == a) { - pr_debug("%s uses %s!\n", a->name, b->name); - return 1; - } - } - pr_debug("%s does not use %s!\n", a->name, b->name); - return 0; -} - -/* - * Module a uses b - * - we add 'a' as a "source", 'b' as a "target" of module use - * - the module_use is added to the list of 'b' sources (so - * 'b' can walk the list to see who sourced them), and of 'a' - * targets (so 'a' can see what modules it targets). - */ -static int add_module_usage(struct module *a, struct module *b) -{ - struct module_use *use; - - pr_debug("Allocating new usage for %s.\n", a->name); - use = kmalloc(sizeof(*use), GFP_ATOMIC); - if (!use) - return -ENOMEM; - - use->source = a; - use->target = b; - list_add(&use->source_list, &b->source_list); - list_add(&use->target_list, &a->target_list); - return 0; -} - -/* Module a uses b: caller needs module_mutex() */ -static int ref_module(struct module *a, struct module *b) -{ - int err; - - if (b == NULL || already_uses(a, b)) - return 0; - - /* If module isn't available, we fail. */ - err = strong_try_module_get(b); - if (err) - return err; - - err = add_module_usage(a, b); - if (err) { - module_put(b); - return err; - } - return 0; -} - -/* Clear the unload stuff of the module. */ -static void module_unload_free(struct module *mod) -{ - struct module_use *use, *tmp; - - mutex_lock(&module_mutex); - list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { - struct module *i = use->target; - pr_debug("%s unusing %s\n", mod->name, i->name); - module_put(i); - list_del(&use->source_list); - list_del(&use->target_list); - kfree(use); - } - mutex_unlock(&module_mutex); -} - -#ifdef CONFIG_MODULE_FORCE_UNLOAD -static inline int try_force_unload(unsigned int flags) -{ - int ret = (flags & O_TRUNC); - if (ret) - add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); - return ret; -} -#else -static inline int try_force_unload(unsigned int flags) -{ - return 0; -} -#endif /* CONFIG_MODULE_FORCE_UNLOAD */ - -/* Try to release refcount of module, 0 means success. */ -static int try_release_module_ref(struct module *mod) -{ - int ret; - - /* Try to decrement refcnt which we set at loading */ - ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); - BUG_ON(ret < 0); - if (ret) - /* Someone can put this right now, recover with checking */ - ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); - - return ret; -} - -static int try_stop_module(struct module *mod, int flags, int *forced) -{ - /* If it's not unused, quit unless we're forcing. */ - if (try_release_module_ref(mod) != 0) { - *forced = try_force_unload(flags); - if (!(*forced)) - return -EWOULDBLOCK; - } - - /* Mark it as dying. */ - mod->state = MODULE_STATE_GOING; - - return 0; -} - -/** - * module_refcount() - return the refcount or -1 if unloading - * @mod: the module we're checking - * - * Return: - * -1 if the module is in the process of unloading - * otherwise the number of references in the kernel to the module - */ -int module_refcount(struct module *mod) -{ - return atomic_read(&mod->refcnt) - MODULE_REF_BASE; -} -EXPORT_SYMBOL(module_refcount); - -/* This exists whether we can unload or not */ -static void free_module(struct module *mod); - -SYSCALL_DEFINE2(delete_module, const char __user *, name_user, - unsigned int, flags) -{ - struct module *mod; - char name[MODULE_NAME_LEN]; - int ret, forced = 0; - - if (!capable(CAP_SYS_MODULE) || modules_disabled) - return -EPERM; - - if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) - return -EFAULT; - name[MODULE_NAME_LEN-1] = '\0'; - - audit_log_kern_module(name); - - if (mutex_lock_interruptible(&module_mutex) != 0) - return -EINTR; - - mod = find_module(name); - if (!mod) { - ret = -ENOENT; - goto out; - } - - if (!list_empty(&mod->source_list)) { - /* Other modules depend on us: get rid of them first. */ - ret = -EWOULDBLOCK; - goto out; - } - - /* Doing init or already dying? */ - if (mod->state != MODULE_STATE_LIVE) { - /* FIXME: if (force), slam module count damn the torpedoes */ - pr_debug("%s already dying\n", mod->name); - ret = -EBUSY; - goto out; - } - - /* If it has an init func, it must have an exit func to unload */ - if (mod->init && !mod->exit) { - forced = try_force_unload(flags); - if (!forced) { - /* This module can't be removed */ - ret = -EBUSY; - goto out; - } - } - - ret = try_stop_module(mod, flags, &forced); - if (ret != 0) - goto out; - - mutex_unlock(&module_mutex); - /* Final destruction now no one is using it. */ - if (mod->exit != NULL) - mod->exit(); - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_GOING, mod); - klp_module_going(mod); - ftrace_release_mod(mod); - - async_synchronize_full(); - - /* Store the name of the last unloaded module for diagnostic purposes */ - strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); - - free_module(mod); - /* someone could wait for the module in add_unformed_module() */ - wake_up_all(&module_wq); - return 0; -out: - mutex_unlock(&module_mutex); - return ret; -} - -static inline void print_unload_info(struct seq_file *m, struct module *mod) -{ - struct module_use *use; - int printed_something = 0; - - seq_printf(m, " %i ", module_refcount(mod)); - - /* - * Always include a trailing , so userspace can differentiate - * between this and the old multi-field proc format. - */ - list_for_each_entry(use, &mod->source_list, source_list) { - printed_something = 1; - seq_printf(m, "%s,", use->source->name); - } - - if (mod->init != NULL && mod->exit == NULL) { - printed_something = 1; - seq_puts(m, "[permanent],"); - } - - if (!printed_something) - seq_puts(m, "-"); -} - -void __symbol_put(const char *symbol) -{ - struct find_symbol_arg fsa = { - .name = symbol, - .gplok = true, - }; - - preempt_disable(); - BUG_ON(!find_symbol(&fsa)); - module_put(fsa.owner); - preempt_enable(); -} -EXPORT_SYMBOL(__symbol_put); - -/* Note this assumes addr is a function, which it currently always is. */ -void symbol_put_addr(void *addr) -{ - struct module *modaddr; - unsigned long a = (unsigned long)dereference_function_descriptor(addr); - - if (core_kernel_text(a)) - return; - - /* - * Even though we hold a reference on the module; we still need to - * disable preemption in order to safely traverse the data structure. - */ - preempt_disable(); - modaddr = __module_text_address(a); - BUG_ON(!modaddr); - module_put(modaddr); - preempt_enable(); -} -EXPORT_SYMBOL_GPL(symbol_put_addr); - -static ssize_t show_refcnt(struct module_attribute *mattr, - struct module_kobject *mk, char *buffer) -{ - return sprintf(buffer, "%i\n", module_refcount(mk->mod)); -} - -static struct module_attribute modinfo_refcnt = - __ATTR(refcnt, 0444, show_refcnt, NULL); - -void __module_get(struct module *module) -{ - if (module) { - preempt_disable(); - atomic_inc(&module->refcnt); - trace_module_get(module, _RET_IP_); - preempt_enable(); - } -} -EXPORT_SYMBOL(__module_get); - -bool try_module_get(struct module *module) -{ - bool ret = true; - - if (module) { - preempt_disable(); - /* Note: here, we can fail to get a reference */ - if (likely(module_is_live(module) && - atomic_inc_not_zero(&module->refcnt) != 0)) - trace_module_get(module, _RET_IP_); - else - ret = false; - - preempt_enable(); - } - return ret; -} -EXPORT_SYMBOL(try_module_get); - -void module_put(struct module *module) -{ - int ret; - - if (module) { - preempt_disable(); - ret = atomic_dec_if_positive(&module->refcnt); - WARN_ON(ret < 0); /* Failed to put refcount */ - trace_module_put(module, _RET_IP_); - preempt_enable(); - } -} -EXPORT_SYMBOL(module_put); - -#else /* !CONFIG_MODULE_UNLOAD */ -static inline void print_unload_info(struct seq_file *m, struct module *mod) -{ - /* We don't know the usage count, or what modules are using. */ - seq_puts(m, " - -"); -} - -static inline void module_unload_free(struct module *mod) -{ -} - -static int ref_module(struct module *a, struct module *b) -{ - return strong_try_module_get(b); -} - -static inline int module_unload_init(struct module *mod) -{ - return 0; -} -#endif /* CONFIG_MODULE_UNLOAD */ - -static size_t module_flags_taint(struct module *mod, char *buf) -{ - size_t l = 0; - int i; - - for (i = 0; i < TAINT_FLAGS_COUNT; i++) { - if (taint_flags[i].module && test_bit(i, &mod->taints)) - buf[l++] = taint_flags[i].c_true; - } - - return l; -} - -static ssize_t show_initstate(struct module_attribute *mattr, - struct module_kobject *mk, char *buffer) -{ - const char *state = "unknown"; - - switch (mk->mod->state) { - case MODULE_STATE_LIVE: - state = "live"; - break; - case MODULE_STATE_COMING: - state = "coming"; - break; - case MODULE_STATE_GOING: - state = "going"; - break; - default: - BUG(); - } - return sprintf(buffer, "%s\n", state); -} - -static struct module_attribute modinfo_initstate = - __ATTR(initstate, 0444, show_initstate, NULL); - -static ssize_t store_uevent(struct module_attribute *mattr, - struct module_kobject *mk, - const char *buffer, size_t count) -{ - int rc; - - rc = kobject_synth_uevent(&mk->kobj, buffer, count); - return rc ? rc : count; -} - -struct module_attribute module_uevent = - __ATTR(uevent, 0200, NULL, store_uevent); - -static ssize_t show_coresize(struct module_attribute *mattr, - struct module_kobject *mk, char *buffer) -{ - return sprintf(buffer, "%u\n", mk->mod->core_layout.size); -} - -static struct module_attribute modinfo_coresize = - __ATTR(coresize, 0444, show_coresize, NULL); - -static ssize_t show_initsize(struct module_attribute *mattr, - struct module_kobject *mk, char *buffer) -{ - return sprintf(buffer, "%u\n", mk->mod->init_layout.size); -} - -static struct module_attribute modinfo_initsize = - __ATTR(initsize, 0444, show_initsize, NULL); - -static ssize_t show_taint(struct module_attribute *mattr, - struct module_kobject *mk, char *buffer) -{ - size_t l; - - l = module_flags_taint(mk->mod, buffer); - buffer[l++] = '\n'; - return l; -} - -static struct module_attribute modinfo_taint = - __ATTR(taint, 0444, show_taint, NULL); - -static struct module_attribute *modinfo_attrs[] = { - &module_uevent, - &modinfo_version, - &modinfo_srcversion, - &modinfo_initstate, - &modinfo_coresize, - &modinfo_initsize, - &modinfo_taint, -#ifdef CONFIG_MODULE_UNLOAD - &modinfo_refcnt, -#endif - NULL, -}; - -static const char vermagic[] = VERMAGIC_STRING; - -static int try_to_force_load(struct module *mod, const char *reason) -{ -#ifdef CONFIG_MODULE_FORCE_LOAD - if (!test_taint(TAINT_FORCED_MODULE)) - pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); - add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); - return 0; -#else - return -ENOEXEC; -#endif -} - -#ifdef CONFIG_MODVERSIONS - -static u32 resolve_rel_crc(const s32 *crc) -{ - return *(u32 *)((void *)crc + *crc); -} - -static int check_version(const struct load_info *info, - const char *symname, - struct module *mod, - const s32 *crc) -{ - Elf_Shdr *sechdrs = info->sechdrs; - unsigned int versindex = info->index.vers; - unsigned int i, num_versions; - struct modversion_info *versions; - - /* Exporting module didn't supply crcs? OK, we're already tainted. */ - if (!crc) - return 1; - - /* No versions at all? modprobe --force does this. */ - if (versindex == 0) - return try_to_force_load(mod, symname) == 0; - - versions = (void *) sechdrs[versindex].sh_addr; - num_versions = sechdrs[versindex].sh_size - / sizeof(struct modversion_info); - - for (i = 0; i < num_versions; i++) { - u32 crcval; - - if (strcmp(versions[i].name, symname) != 0) - continue; - - if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) - crcval = resolve_rel_crc(crc); - else - crcval = *crc; - if (versions[i].crc == crcval) - return 1; - pr_debug("Found checksum %X vs module %lX\n", - crcval, versions[i].crc); - goto bad_version; - } - - /* Broken toolchain. Warn once, then let it go.. */ - pr_warn_once("%s: no symbol version for %s\n", info->name, symname); - return 1; - -bad_version: - pr_warn("%s: disagrees about version of symbol %s\n", - info->name, symname); - return 0; -} - -static inline int check_modstruct_version(const struct load_info *info, - struct module *mod) -{ - struct find_symbol_arg fsa = { - .name = "module_layout", - .gplok = true, - }; - - /* - * Since this should be found in kernel (which can't be removed), no - * locking is necessary -- use preempt_disable() to placate lockdep. - */ - preempt_disable(); - if (!find_symbol(&fsa)) { - preempt_enable(); - BUG(); - } - preempt_enable(); - return check_version(info, "module_layout", mod, fsa.crc); -} - -/* First part is kernel version, which we ignore if module has crcs. */ -static inline int same_magic(const char *amagic, const char *bmagic, - bool has_crcs) -{ - if (has_crcs) { - amagic += strcspn(amagic, " "); - bmagic += strcspn(bmagic, " "); - } - return strcmp(amagic, bmagic) == 0; -} -#else -static inline int check_version(const struct load_info *info, - const char *symname, - struct module *mod, - const s32 *crc) -{ - return 1; -} - -static inline int check_modstruct_version(const struct load_info *info, - struct module *mod) -{ - return 1; -} - -static inline int same_magic(const char *amagic, const char *bmagic, - bool has_crcs) -{ - return strcmp(amagic, bmagic) == 0; -} -#endif /* CONFIG_MODVERSIONS */ - -static char *get_modinfo(const struct load_info *info, const char *tag); -static char *get_next_modinfo(const struct load_info *info, const char *tag, - char *prev); - -static int verify_namespace_is_imported(const struct load_info *info, - const struct kernel_symbol *sym, - struct module *mod) -{ - const char *namespace; - char *imported_namespace; - - namespace = kernel_symbol_namespace(sym); - if (namespace && namespace[0]) { - imported_namespace = get_modinfo(info, "import_ns"); - while (imported_namespace) { - if (strcmp(namespace, imported_namespace) == 0) - return 0; - imported_namespace = get_next_modinfo( - info, "import_ns", imported_namespace); - } -#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS - pr_warn( -#else - pr_err( -#endif - "%s: module uses symbol (%s) from namespace %s, but does not import it.\n", - mod->name, kernel_symbol_name(sym), namespace); -#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS - return -EINVAL; -#endif - } - return 0; -} - -static bool inherit_taint(struct module *mod, struct module *owner) -{ - if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) - return true; - - if (mod->using_gplonly_symbols) { - pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n", - mod->name, owner->name); - return false; - } - - if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { - pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n", - mod->name, owner->name); - set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); - } - return true; -} - -/* Resolve a symbol for this module. I.e. if we find one, record usage. */ -static const struct kernel_symbol *resolve_symbol(struct module *mod, - const struct load_info *info, - const char *name, - char ownername[]) -{ - struct find_symbol_arg fsa = { - .name = name, - .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), - .warn = true, - }; - int err; - - /* - * The module_mutex should not be a heavily contended lock; - * if we get the occasional sleep here, we'll go an extra iteration - * in the wait_event_interruptible(), which is harmless. - */ - sched_annotate_sleep(); - mutex_lock(&module_mutex); - if (!find_symbol(&fsa)) - goto unlock; - - if (fsa.license == GPL_ONLY) - mod->using_gplonly_symbols = true; - - if (!inherit_taint(mod, fsa.owner)) { - fsa.sym = NULL; - goto getname; - } - - if (!check_version(info, name, mod, fsa.crc)) { - fsa.sym = ERR_PTR(-EINVAL); - goto getname; - } - - err = verify_namespace_is_imported(info, fsa.sym, mod); - if (err) { - fsa.sym = ERR_PTR(err); - goto getname; - } - - err = ref_module(mod, fsa.owner); - if (err) { - fsa.sym = ERR_PTR(err); - goto getname; - } - -getname: - /* We must make copy under the lock if we failed to get ref. */ - strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); -unlock: - mutex_unlock(&module_mutex); - return fsa.sym; -} - -static const struct kernel_symbol * -resolve_symbol_wait(struct module *mod, - const struct load_info *info, - const char *name) -{ - const struct kernel_symbol *ksym; - char owner[MODULE_NAME_LEN]; - - if (wait_event_interruptible_timeout(module_wq, - !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) - || PTR_ERR(ksym) != -EBUSY, - 30 * HZ) <= 0) { - pr_warn("%s: gave up waiting for init of module %s.\n", - mod->name, owner); - } - return ksym; -} - -#ifdef CONFIG_KALLSYMS -static inline bool sect_empty(const Elf_Shdr *sect) -{ - return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; -} -#endif - -/* - * /sys/module/foo/sections stuff - * J. Corbet - */ -#ifdef CONFIG_SYSFS - -#ifdef CONFIG_KALLSYMS -struct module_sect_attr { - struct bin_attribute battr; - unsigned long address; -}; - -struct module_sect_attrs { - struct attribute_group grp; - unsigned int nsections; - struct module_sect_attr attrs[]; -}; - -#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) -static ssize_t module_sect_read(struct file *file, struct kobject *kobj, - struct bin_attribute *battr, - char *buf, loff_t pos, size_t count) -{ - struct module_sect_attr *sattr = - container_of(battr, struct module_sect_attr, battr); - char bounce[MODULE_SECT_READ_SIZE + 1]; - size_t wrote; - - if (pos != 0) - return -EINVAL; - - /* - * Since we're a binary read handler, we must account for the - * trailing NUL byte that sprintf will write: if "buf" is - * too small to hold the NUL, or the NUL is exactly the last - * byte, the read will look like it got truncated by one byte. - * Since there is no way to ask sprintf nicely to not write - * the NUL, we have to use a bounce buffer. - */ - wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", - kallsyms_show_value(file->f_cred) - ? (void *)sattr->address : NULL); - count = min(count, wrote); - memcpy(buf, bounce, count); - - return count; -} - -static void free_sect_attrs(struct module_sect_attrs *sect_attrs) -{ - unsigned int section; - - for (section = 0; section < sect_attrs->nsections; section++) - kfree(sect_attrs->attrs[section].battr.attr.name); - kfree(sect_attrs); -} - -static void add_sect_attrs(struct module *mod, const struct load_info *info) -{ - unsigned int nloaded = 0, i, size[2]; - struct module_sect_attrs *sect_attrs; - struct module_sect_attr *sattr; - struct bin_attribute **gattr; - - /* Count loaded sections and allocate structures */ - for (i = 0; i < info->hdr->e_shnum; i++) - if (!sect_empty(&info->sechdrs[i])) - nloaded++; - size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), - sizeof(sect_attrs->grp.bin_attrs[0])); - size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); - sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); - if (sect_attrs == NULL) - return; - - /* Setup section attributes. */ - sect_attrs->grp.name = "sections"; - sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; - - sect_attrs->nsections = 0; - sattr = §_attrs->attrs[0]; - gattr = §_attrs->grp.bin_attrs[0]; - for (i = 0; i < info->hdr->e_shnum; i++) { - Elf_Shdr *sec = &info->sechdrs[i]; - if (sect_empty(sec)) - continue; - sysfs_bin_attr_init(&sattr->battr); - sattr->address = sec->sh_addr; - sattr->battr.attr.name = - kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); - if (sattr->battr.attr.name == NULL) - goto out; - sect_attrs->nsections++; - sattr->battr.read = module_sect_read; - sattr->battr.size = MODULE_SECT_READ_SIZE; - sattr->battr.attr.mode = 0400; - *(gattr++) = &(sattr++)->battr; - } - *gattr = NULL; - - if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) - goto out; - - mod->sect_attrs = sect_attrs; - return; - out: - free_sect_attrs(sect_attrs); -} - -static void remove_sect_attrs(struct module *mod) -{ - if (mod->sect_attrs) { - sysfs_remove_group(&mod->mkobj.kobj, - &mod->sect_attrs->grp); - /* - * We are positive that no one is using any sect attrs - * at this point. Deallocate immediately. - */ - free_sect_attrs(mod->sect_attrs); - mod->sect_attrs = NULL; - } -} - -/* - * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. - */ - -struct module_notes_attrs { - struct kobject *dir; - unsigned int notes; - struct bin_attribute attrs[]; -}; - -static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t pos, size_t count) -{ - /* - * The caller checked the pos and count against our size. - */ - memcpy(buf, bin_attr->private + pos, count); - return count; -} - -static void free_notes_attrs(struct module_notes_attrs *notes_attrs, - unsigned int i) -{ - if (notes_attrs->dir) { - while (i-- > 0) - sysfs_remove_bin_file(notes_attrs->dir, - ¬es_attrs->attrs[i]); - kobject_put(notes_attrs->dir); - } - kfree(notes_attrs); -} - -static void add_notes_attrs(struct module *mod, const struct load_info *info) -{ - unsigned int notes, loaded, i; - struct module_notes_attrs *notes_attrs; - struct bin_attribute *nattr; - - /* failed to create section attributes, so can't create notes */ - if (!mod->sect_attrs) - return; - - /* Count notes sections and allocate structures. */ - notes = 0; - for (i = 0; i < info->hdr->e_shnum; i++) - if (!sect_empty(&info->sechdrs[i]) && - (info->sechdrs[i].sh_type == SHT_NOTE)) - ++notes; - - if (notes == 0) - return; - - notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), - GFP_KERNEL); - if (notes_attrs == NULL) - return; - - notes_attrs->notes = notes; - nattr = ¬es_attrs->attrs[0]; - for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { - if (sect_empty(&info->sechdrs[i])) - continue; - if (info->sechdrs[i].sh_type == SHT_NOTE) { - sysfs_bin_attr_init(nattr); - nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; - nattr->attr.mode = S_IRUGO; - nattr->size = info->sechdrs[i].sh_size; - nattr->private = (void *) info->sechdrs[i].sh_addr; - nattr->read = module_notes_read; - ++nattr; - } - ++loaded; - } - - notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); - if (!notes_attrs->dir) - goto out; - - for (i = 0; i < notes; ++i) - if (sysfs_create_bin_file(notes_attrs->dir, - ¬es_attrs->attrs[i])) - goto out; - - mod->notes_attrs = notes_attrs; - return; - - out: - free_notes_attrs(notes_attrs, i); -} - -static void remove_notes_attrs(struct module *mod) -{ - if (mod->notes_attrs) - free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); -} - -#else - -static inline void add_sect_attrs(struct module *mod, - const struct load_info *info) -{ -} - -static inline void remove_sect_attrs(struct module *mod) -{ -} - -static inline void add_notes_attrs(struct module *mod, - const struct load_info *info) -{ -} - -static inline void remove_notes_attrs(struct module *mod) -{ -} -#endif /* CONFIG_KALLSYMS */ - -static void del_usage_links(struct module *mod) -{ -#ifdef CONFIG_MODULE_UNLOAD - struct module_use *use; - - mutex_lock(&module_mutex); - list_for_each_entry(use, &mod->target_list, target_list) - sysfs_remove_link(use->target->holders_dir, mod->name); - mutex_unlock(&module_mutex); -#endif -} - -static int add_usage_links(struct module *mod) -{ - int ret = 0; -#ifdef CONFIG_MODULE_UNLOAD - struct module_use *use; - - mutex_lock(&module_mutex); - list_for_each_entry(use, &mod->target_list, target_list) { - ret = sysfs_create_link(use->target->holders_dir, - &mod->mkobj.kobj, mod->name); - if (ret) - break; - } - mutex_unlock(&module_mutex); - if (ret) - del_usage_links(mod); -#endif - return ret; -} - -static void module_remove_modinfo_attrs(struct module *mod, int end); - -static int module_add_modinfo_attrs(struct module *mod) -{ - struct module_attribute *attr; - struct module_attribute *temp_attr; - int error = 0; - int i; - - mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * - (ARRAY_SIZE(modinfo_attrs) + 1)), - GFP_KERNEL); - if (!mod->modinfo_attrs) - return -ENOMEM; - - temp_attr = mod->modinfo_attrs; - for (i = 0; (attr = modinfo_attrs[i]); i++) { - if (!attr->test || attr->test(mod)) { - memcpy(temp_attr, attr, sizeof(*temp_attr)); - sysfs_attr_init(&temp_attr->attr); - error = sysfs_create_file(&mod->mkobj.kobj, - &temp_attr->attr); - if (error) - goto error_out; - ++temp_attr; - } - } - - return 0; - -error_out: - if (i > 0) - module_remove_modinfo_attrs(mod, --i); - else - kfree(mod->modinfo_attrs); - return error; -} - -static void module_remove_modinfo_attrs(struct module *mod, int end) -{ - struct module_attribute *attr; - int i; - - for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { - if (end >= 0 && i > end) - break; - /* pick a field to test for end of list */ - if (!attr->attr.name) - break; - sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); - if (attr->free) - attr->free(mod); - } - kfree(mod->modinfo_attrs); -} - -static void mod_kobject_put(struct module *mod) -{ - DECLARE_COMPLETION_ONSTACK(c); - mod->mkobj.kobj_completion = &c; - kobject_put(&mod->mkobj.kobj); - wait_for_completion(&c); -} - -static int mod_sysfs_init(struct module *mod) -{ - int err; - struct kobject *kobj; - - if (!module_sysfs_initialized) { - pr_err("%s: module sysfs not initialized\n", mod->name); - err = -EINVAL; - goto out; - } - - kobj = kset_find_obj(module_kset, mod->name); - if (kobj) { - pr_err("%s: module is already loaded\n", mod->name); - kobject_put(kobj); - err = -EINVAL; - goto out; - } - - mod->mkobj.mod = mod; - - memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); - mod->mkobj.kobj.kset = module_kset; - err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, - "%s", mod->name); - if (err) - mod_kobject_put(mod); - -out: - return err; -} - -static int mod_sysfs_setup(struct module *mod, - const struct load_info *info, - struct kernel_param *kparam, - unsigned int num_params) -{ - int err; - - err = mod_sysfs_init(mod); - if (err) - goto out; - - mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); - if (!mod->holders_dir) { - err = -ENOMEM; - goto out_unreg; - } - - err = module_param_sysfs_setup(mod, kparam, num_params); - if (err) - goto out_unreg_holders; - - err = module_add_modinfo_attrs(mod); - if (err) - goto out_unreg_param; - - err = add_usage_links(mod); - if (err) - goto out_unreg_modinfo_attrs; - - add_sect_attrs(mod, info); - add_notes_attrs(mod, info); - - return 0; - -out_unreg_modinfo_attrs: - module_remove_modinfo_attrs(mod, -1); -out_unreg_param: - module_param_sysfs_remove(mod); -out_unreg_holders: - kobject_put(mod->holders_dir); -out_unreg: - mod_kobject_put(mod); -out: - return err; -} - -static void mod_sysfs_fini(struct module *mod) -{ - remove_notes_attrs(mod); - remove_sect_attrs(mod); - mod_kobject_put(mod); -} - -static void init_param_lock(struct module *mod) -{ - mutex_init(&mod->param_lock); -} -#else /* !CONFIG_SYSFS */ - -static int mod_sysfs_setup(struct module *mod, - const struct load_info *info, - struct kernel_param *kparam, - unsigned int num_params) -{ - return 0; -} - -static void mod_sysfs_fini(struct module *mod) -{ -} - -static void module_remove_modinfo_attrs(struct module *mod, int end) -{ -} - -static void del_usage_links(struct module *mod) -{ -} - -static void init_param_lock(struct module *mod) -{ -} -#endif /* CONFIG_SYSFS */ - -static void mod_sysfs_teardown(struct module *mod) -{ - del_usage_links(mod); - module_remove_modinfo_attrs(mod, -1); - module_param_sysfs_remove(mod); - kobject_put(mod->mkobj.drivers_dir); - kobject_put(mod->holders_dir); - mod_sysfs_fini(mod); -} - -/* - * LKM RO/NX protection: protect module's text/ro-data - * from modification and any data from execution. - * - * General layout of module is: - * [text] [read-only-data] [ro-after-init] [writable data] - * text_size -----^ ^ ^ ^ - * ro_size ------------------------| | | - * ro_after_init_size -----------------------------| | - * size -----------------------------------------------------------| - * - * These values are always page-aligned (as is base) - */ - -/* - * Since some arches are moving towards PAGE_KERNEL module allocations instead - * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the - * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of - * whether we are strict. - */ -#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX -static void frob_text(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base, - layout->text_size >> PAGE_SHIFT); -} - -static void module_enable_x(const struct module *mod) -{ - frob_text(&mod->core_layout, set_memory_x); - frob_text(&mod->init_layout, set_memory_x); -} -#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ -static void module_enable_x(const struct module *mod) { } -#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ - -#ifdef CONFIG_STRICT_MODULE_RWX -static void frob_rodata(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->text_size, - (layout->ro_size - layout->text_size) >> PAGE_SHIFT); -} - -static void frob_ro_after_init(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->ro_size, - (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); -} - -static void frob_writable_data(const struct module_layout *layout, - int (*set_memory)(unsigned long start, int num_pages)) -{ - BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->ro_after_init_size, - (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); -} - -static void module_enable_ro(const struct module *mod, bool after_init) -{ - if (!rodata_enabled) - return; - - set_vm_flush_reset_perms(mod->core_layout.base); - set_vm_flush_reset_perms(mod->init_layout.base); - frob_text(&mod->core_layout, set_memory_ro); - - frob_rodata(&mod->core_layout, set_memory_ro); - frob_text(&mod->init_layout, set_memory_ro); - frob_rodata(&mod->init_layout, set_memory_ro); - - if (after_init) - frob_ro_after_init(&mod->core_layout, set_memory_ro); -} - -static void module_enable_nx(const struct module *mod) -{ - frob_rodata(&mod->core_layout, set_memory_nx); - frob_ro_after_init(&mod->core_layout, set_memory_nx); - frob_writable_data(&mod->core_layout, set_memory_nx); - frob_rodata(&mod->init_layout, set_memory_nx); - frob_writable_data(&mod->init_layout, set_memory_nx); -} - -static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, - char *secstrings, struct module *mod) -{ - const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR; - int i; - - for (i = 0; i < hdr->e_shnum; i++) { - if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) { - pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n", - mod->name, secstrings + sechdrs[i].sh_name, i); - return -ENOEXEC; - } - } - - return 0; -} - -#else /* !CONFIG_STRICT_MODULE_RWX */ -static void module_enable_nx(const struct module *mod) { } -static void module_enable_ro(const struct module *mod, bool after_init) {} -static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, - char *secstrings, struct module *mod) -{ - return 0; -} -#endif /* CONFIG_STRICT_MODULE_RWX */ - -#ifdef CONFIG_LIVEPATCH -/* - * Persist Elf information about a module. Copy the Elf header, - * section header table, section string table, and symtab section - * index from info to mod->klp_info. - */ -static int copy_module_elf(struct module *mod, struct load_info *info) -{ - unsigned int size, symndx; - int ret; - - size = sizeof(*mod->klp_info); - mod->klp_info = kmalloc(size, GFP_KERNEL); - if (mod->klp_info == NULL) - return -ENOMEM; - - /* Elf header */ - size = sizeof(mod->klp_info->hdr); - memcpy(&mod->klp_info->hdr, info->hdr, size); - - /* Elf section header table */ - size = sizeof(*info->sechdrs) * info->hdr->e_shnum; - mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); - if (mod->klp_info->sechdrs == NULL) { - ret = -ENOMEM; - goto free_info; - } - - /* Elf section name string table */ - size = info->sechdrs[info->hdr->e_shstrndx].sh_size; - mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); - if (mod->klp_info->secstrings == NULL) { - ret = -ENOMEM; - goto free_sechdrs; - } - - /* Elf symbol section index */ - symndx = info->index.sym; - mod->klp_info->symndx = symndx; - - /* - * For livepatch modules, core_kallsyms.symtab is a complete - * copy of the original symbol table. Adjust sh_addr to point - * to core_kallsyms.symtab since the copy of the symtab in module - * init memory is freed at the end of do_init_module(). - */ - mod->klp_info->sechdrs[symndx].sh_addr = \ - (unsigned long) mod->core_kallsyms.symtab; - - return 0; - -free_sechdrs: - kfree(mod->klp_info->sechdrs); -free_info: - kfree(mod->klp_info); - return ret; -} - -static void free_module_elf(struct module *mod) -{ - kfree(mod->klp_info->sechdrs); - kfree(mod->klp_info->secstrings); - kfree(mod->klp_info); -} -#else /* !CONFIG_LIVEPATCH */ -static int copy_module_elf(struct module *mod, struct load_info *info) -{ - return 0; -} - -static void free_module_elf(struct module *mod) -{ -} -#endif /* CONFIG_LIVEPATCH */ - -void __weak module_memfree(void *module_region) -{ - /* - * This memory may be RO, and freeing RO memory in an interrupt is not - * supported by vmalloc. - */ - WARN_ON(in_interrupt()); - vfree(module_region); -} - -void __weak module_arch_cleanup(struct module *mod) -{ -} - -void __weak module_arch_freeing_init(struct module *mod) -{ -} - -static void cfi_cleanup(struct module *mod); - -/* Free a module, remove from lists, etc. */ -static void free_module(struct module *mod) -{ - trace_module_free(mod); - - mod_sysfs_teardown(mod); - - /* - * We leave it in list to prevent duplicate loads, but make sure - * that noone uses it while it's being deconstructed. - */ - mutex_lock(&module_mutex); - mod->state = MODULE_STATE_UNFORMED; - mutex_unlock(&module_mutex); - - /* Remove dynamic debug info */ - ddebug_remove_module(mod->name); - - /* Arch-specific cleanup. */ - module_arch_cleanup(mod); - - /* Module unload stuff */ - module_unload_free(mod); - - /* Free any allocated parameters. */ - destroy_params(mod->kp, mod->num_kp); - - if (is_livepatch_module(mod)) - free_module_elf(mod); - - /* Now we can delete it from the lists */ - mutex_lock(&module_mutex); - /* Unlink carefully: kallsyms could be walking list. */ - list_del_rcu(&mod->list); - mod_tree_remove(mod); - /* Remove this module from bug list, this uses list_del_rcu */ - module_bug_cleanup(mod); - /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ - synchronize_rcu(); - mutex_unlock(&module_mutex); - - /* Clean up CFI for the module. */ - cfi_cleanup(mod); - - /* This may be empty, but that's OK */ - module_arch_freeing_init(mod); - module_memfree(mod->init_layout.base); - kfree(mod->args); - percpu_modfree(mod); - - /* Free lock-classes; relies on the preceding sync_rcu(). */ - lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); - - /* Finally, free the core (containing the module structure) */ - module_memfree(mod->core_layout.base); -} - -void *__symbol_get(const char *symbol) -{ - struct find_symbol_arg fsa = { - .name = symbol, - .gplok = true, - .warn = true, - }; - - preempt_disable(); - if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) { - preempt_enable(); - return NULL; - } - preempt_enable(); - return (void *)kernel_symbol_value(fsa.sym); -} -EXPORT_SYMBOL_GPL(__symbol_get); - -/* - * Ensure that an exported symbol [global namespace] does not already exist - * in the kernel or in some other module's exported symbol table. - * - * You must hold the module_mutex. - */ -static int verify_exported_symbols(struct module *mod) -{ - unsigned int i; - const struct kernel_symbol *s; - struct { - const struct kernel_symbol *sym; - unsigned int num; - } arr[] = { - { mod->syms, mod->num_syms }, - { mod->gpl_syms, mod->num_gpl_syms }, - }; - - for (i = 0; i < ARRAY_SIZE(arr); i++) { - for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { - struct find_symbol_arg fsa = { - .name = kernel_symbol_name(s), - .gplok = true, - }; - if (find_symbol(&fsa)) { - pr_err("%s: exports duplicate symbol %s" - " (owned by %s)\n", - mod->name, kernel_symbol_name(s), - module_name(fsa.owner)); - return -ENOEXEC; - } - } - } - return 0; -} - -static bool ignore_undef_symbol(Elf_Half emachine, const char *name) -{ - /* - * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as - * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64. - * i386 has a similar problem but may not deserve a fix. - * - * If we ever have to ignore many symbols, consider refactoring the code to - * only warn if referenced by a relocation. - */ - if (emachine == EM_386 || emachine == EM_X86_64) - return !strcmp(name, "_GLOBAL_OFFSET_TABLE_"); - return false; -} - -/* Change all symbols so that st_value encodes the pointer directly. */ -static int simplify_symbols(struct module *mod, const struct load_info *info) -{ - Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; - Elf_Sym *sym = (void *)symsec->sh_addr; - unsigned long secbase; - unsigned int i; - int ret = 0; - const struct kernel_symbol *ksym; - - for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { - const char *name = info->strtab + sym[i].st_name; - - switch (sym[i].st_shndx) { - case SHN_COMMON: - /* Ignore common symbols */ - if (!strncmp(name, "__gnu_lto", 9)) - break; - - /* - * We compiled with -fno-common. These are not - * supposed to happen. - */ - pr_debug("Common symbol: %s\n", name); - pr_warn("%s: please compile with -fno-common\n", - mod->name); - ret = -ENOEXEC; - break; - - case SHN_ABS: - /* Don't need to do anything */ - pr_debug("Absolute symbol: 0x%08lx\n", - (long)sym[i].st_value); - break; - - case SHN_LIVEPATCH: - /* Livepatch symbols are resolved by livepatch */ - break; - - case SHN_UNDEF: - ksym = resolve_symbol_wait(mod, info, name); - /* Ok if resolved. */ - if (ksym && !IS_ERR(ksym)) { - sym[i].st_value = kernel_symbol_value(ksym); - break; - } - - /* Ok if weak or ignored. */ - if (!ksym && - (ELF_ST_BIND(sym[i].st_info) == STB_WEAK || - ignore_undef_symbol(info->hdr->e_machine, name))) - break; - - ret = PTR_ERR(ksym) ?: -ENOENT; - pr_warn("%s: Unknown symbol %s (err %d)\n", - mod->name, name, ret); - break; - - default: - /* Divert to percpu allocation if a percpu var. */ - if (sym[i].st_shndx == info->index.pcpu) - secbase = (unsigned long)mod_percpu(mod); - else - secbase = info->sechdrs[sym[i].st_shndx].sh_addr; - sym[i].st_value += secbase; - break; - } - } - - return ret; -} - -static int apply_relocations(struct module *mod, const struct load_info *info) -{ - unsigned int i; - int err = 0; - - /* Now do relocations. */ - for (i = 1; i < info->hdr->e_shnum; i++) { - unsigned int infosec = info->sechdrs[i].sh_info; - - /* Not a valid relocation section? */ - if (infosec >= info->hdr->e_shnum) - continue; - - /* Don't bother with non-allocated sections */ - if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) - continue; - - if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) - err = klp_apply_section_relocs(mod, info->sechdrs, - info->secstrings, - info->strtab, - info->index.sym, i, - NULL); - else if (info->sechdrs[i].sh_type == SHT_REL) - err = apply_relocate(info->sechdrs, info->strtab, - info->index.sym, i, mod); - else if (info->sechdrs[i].sh_type == SHT_RELA) - err = apply_relocate_add(info->sechdrs, info->strtab, - info->index.sym, i, mod); - if (err < 0) - break; - } - return err; -} - -/* Additional bytes needed by arch in front of individual sections */ -unsigned int __weak arch_mod_section_prepend(struct module *mod, - unsigned int section) -{ - /* default implementation just returns zero */ - return 0; -} - -/* Update size with this section: return offset. */ -static long get_offset(struct module *mod, unsigned int *size, - Elf_Shdr *sechdr, unsigned int section) -{ - long ret; - - *size += arch_mod_section_prepend(mod, section); - ret = ALIGN(*size, sechdr->sh_addralign ?: 1); - *size = ret + sechdr->sh_size; - return ret; -} - -static bool module_init_layout_section(const char *sname) -{ -#ifndef CONFIG_MODULE_UNLOAD - if (module_exit_section(sname)) - return true; -#endif - return module_init_section(sname); -} - -/* - * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld - * might -- code, read-only data, read-write data, small data. Tally - * sizes, and place the offsets into sh_entsize fields: high bit means it - * belongs in init. - */ -static void layout_sections(struct module *mod, struct load_info *info) -{ - static unsigned long const masks[][2] = { - /* - * NOTE: all executable code must be the first section - * in this array; otherwise modify the text_size - * finder in the two loops below - */ - { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, - { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, - { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, - { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, - { ARCH_SHF_SMALL | SHF_ALLOC, 0 } - }; - unsigned int m, i; - - for (i = 0; i < info->hdr->e_shnum; i++) - info->sechdrs[i].sh_entsize = ~0UL; - - pr_debug("Core section allocation order:\n"); - for (m = 0; m < ARRAY_SIZE(masks); ++m) { - for (i = 0; i < info->hdr->e_shnum; ++i) { - Elf_Shdr *s = &info->sechdrs[i]; - const char *sname = info->secstrings + s->sh_name; - - if ((s->sh_flags & masks[m][0]) != masks[m][0] - || (s->sh_flags & masks[m][1]) - || s->sh_entsize != ~0UL - || module_init_layout_section(sname)) - continue; - s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); - pr_debug("\t%s\n", sname); - } - switch (m) { - case 0: /* executable */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.text_size = mod->core_layout.size; - break; - case 1: /* RO: text and ro-data */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.ro_size = mod->core_layout.size; - break; - case 2: /* RO after init */ - mod->core_layout.size = debug_align(mod->core_layout.size); - mod->core_layout.ro_after_init_size = mod->core_layout.size; - break; - case 4: /* whole core */ - mod->core_layout.size = debug_align(mod->core_layout.size); - break; - } - } - - pr_debug("Init section allocation order:\n"); - for (m = 0; m < ARRAY_SIZE(masks); ++m) { - for (i = 0; i < info->hdr->e_shnum; ++i) { - Elf_Shdr *s = &info->sechdrs[i]; - const char *sname = info->secstrings + s->sh_name; - - if ((s->sh_flags & masks[m][0]) != masks[m][0] - || (s->sh_flags & masks[m][1]) - || s->sh_entsize != ~0UL - || !module_init_layout_section(sname)) - continue; - s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) - | INIT_OFFSET_MASK); - pr_debug("\t%s\n", sname); - } - switch (m) { - case 0: /* executable */ - mod->init_layout.size = debug_align(mod->init_layout.size); - mod->init_layout.text_size = mod->init_layout.size; - break; - case 1: /* RO: text and ro-data */ - mod->init_layout.size = debug_align(mod->init_layout.size); - mod->init_layout.ro_size = mod->init_layout.size; - break; - case 2: - /* - * RO after init doesn't apply to init_layout (only - * core_layout), so it just takes the value of ro_size. - */ - mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; - break; - case 4: /* whole init */ - mod->init_layout.size = debug_align(mod->init_layout.size); - break; - } - } -} - -static void set_license(struct module *mod, const char *license) -{ - if (!license) - license = "unspecified"; - - if (!license_is_gpl_compatible(license)) { - if (!test_taint(TAINT_PROPRIETARY_MODULE)) - pr_warn("%s: module license '%s' taints kernel.\n", - mod->name, license); - add_taint_module(mod, TAINT_PROPRIETARY_MODULE, - LOCKDEP_NOW_UNRELIABLE); - } -} - -/* Parse tag=value strings from .modinfo section */ -static char *next_string(char *string, unsigned long *secsize) -{ - /* Skip non-zero chars */ - while (string[0]) { - string++; - if ((*secsize)-- <= 1) - return NULL; - } - - /* Skip any zero padding. */ - while (!string[0]) { - string++; - if ((*secsize)-- <= 1) - return NULL; - } - return string; -} - -static char *get_next_modinfo(const struct load_info *info, const char *tag, - char *prev) -{ - char *p; - unsigned int taglen = strlen(tag); - Elf_Shdr *infosec = &info->sechdrs[info->index.info]; - unsigned long size = infosec->sh_size; - - /* - * get_modinfo() calls made before rewrite_section_headers() - * must use sh_offset, as sh_addr isn't set! - */ - char *modinfo = (char *)info->hdr + infosec->sh_offset; - - if (prev) { - size -= prev - modinfo; - modinfo = next_string(prev, &size); - } - - for (p = modinfo; p; p = next_string(p, &size)) { - if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') - return p + taglen + 1; - } - return NULL; -} - -static char *get_modinfo(const struct load_info *info, const char *tag) -{ - return get_next_modinfo(info, tag, NULL); -} - -static void setup_modinfo(struct module *mod, struct load_info *info) -{ - struct module_attribute *attr; - int i; - - for (i = 0; (attr = modinfo_attrs[i]); i++) { - if (attr->setup) - attr->setup(mod, get_modinfo(info, attr->attr.name)); - } -} - -static void free_modinfo(struct module *mod) -{ - struct module_attribute *attr; - int i; - - for (i = 0; (attr = modinfo_attrs[i]); i++) { - if (attr->free) - attr->free(mod); - } -} - -#ifdef CONFIG_KALLSYMS - -/* Lookup exported symbol in given range of kernel_symbols */ -static const struct kernel_symbol *lookup_exported_symbol(const char *name, - const struct kernel_symbol *start, - const struct kernel_symbol *stop) -{ - return bsearch(name, start, stop - start, - sizeof(struct kernel_symbol), cmp_name); -} - -static int is_exported(const char *name, unsigned long value, - const struct module *mod) -{ - const struct kernel_symbol *ks; - if (!mod) - ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab); - else - ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms); - - return ks != NULL && kernel_symbol_value(ks) == value; -} - -/* As per nm */ -static char elf_type(const Elf_Sym *sym, const struct load_info *info) -{ - const Elf_Shdr *sechdrs = info->sechdrs; - - if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { - if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) - return 'v'; - else - return 'w'; - } - if (sym->st_shndx == SHN_UNDEF) - return 'U'; - if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu) - return 'a'; - if (sym->st_shndx >= SHN_LORESERVE) - return '?'; - if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) - return 't'; - if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC - && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { - if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) - return 'r'; - else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) - return 'g'; - else - return 'd'; - } - if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { - if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) - return 's'; - else - return 'b'; - } - if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, - ".debug")) { - return 'n'; - } - return '?'; -} - -static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, - unsigned int shnum, unsigned int pcpundx) -{ - const Elf_Shdr *sec; - - if (src->st_shndx == SHN_UNDEF - || src->st_shndx >= shnum - || !src->st_name) - return false; - -#ifdef CONFIG_KALLSYMS_ALL - if (src->st_shndx == pcpundx) - return true; -#endif - - sec = sechdrs + src->st_shndx; - if (!(sec->sh_flags & SHF_ALLOC) -#ifndef CONFIG_KALLSYMS_ALL - || !(sec->sh_flags & SHF_EXECINSTR) -#endif - || (sec->sh_entsize & INIT_OFFSET_MASK)) - return false; - - return true; -} - -/* - * We only allocate and copy the strings needed by the parts of symtab - * we keep. This is simple, but has the effect of making multiple - * copies of duplicates. We could be more sophisticated, see - * linux-kernel thread starting with - * <73defb5e4bca04a6431392cc341112b1@localhost>. - */ -static void layout_symtab(struct module *mod, struct load_info *info) -{ - Elf_Shdr *symsect = info->sechdrs + info->index.sym; - Elf_Shdr *strsect = info->sechdrs + info->index.str; - const Elf_Sym *src; - unsigned int i, nsrc, ndst, strtab_size = 0; - - /* Put symbol section at end of init part of module. */ - symsect->sh_flags |= SHF_ALLOC; - symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect, - info->index.sym) | INIT_OFFSET_MASK; - pr_debug("\t%s\n", info->secstrings + symsect->sh_name); - - src = (void *)info->hdr + symsect->sh_offset; - nsrc = symsect->sh_size / sizeof(*src); - - /* Compute total space required for the core symbols' strtab. */ - for (ndst = i = 0; i < nsrc; i++) { - if (i == 0 || is_livepatch_module(mod) || - is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, - info->index.pcpu)) { - strtab_size += strlen(&info->strtab[src[i].st_name])+1; - ndst++; - } - } - - /* Append room for core symbols at end of core part. */ - info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); - info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); - mod->core_layout.size += strtab_size; - info->core_typeoffs = mod->core_layout.size; - mod->core_layout.size += ndst * sizeof(char); - mod->core_layout.size = debug_align(mod->core_layout.size); - - /* Put string table section at end of init part of module. */ - strsect->sh_flags |= SHF_ALLOC; - strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect, - info->index.str) | INIT_OFFSET_MASK; - pr_debug("\t%s\n", info->secstrings + strsect->sh_name); - - /* We'll tack temporary mod_kallsyms on the end. */ - mod->init_layout.size = ALIGN(mod->init_layout.size, - __alignof__(struct mod_kallsyms)); - info->mod_kallsyms_init_off = mod->init_layout.size; - mod->init_layout.size += sizeof(struct mod_kallsyms); - info->init_typeoffs = mod->init_layout.size; - mod->init_layout.size += nsrc * sizeof(char); - mod->init_layout.size = debug_align(mod->init_layout.size); -} - -/* - * We use the full symtab and strtab which layout_symtab arranged to - * be appended to the init section. Later we switch to the cut-down - * core-only ones. - */ -static void add_kallsyms(struct module *mod, const struct load_info *info) -{ - unsigned int i, ndst; - const Elf_Sym *src; - Elf_Sym *dst; - char *s; - Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; - - /* Set up to point into init section. */ - mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off; - - mod->kallsyms->symtab = (void *)symsec->sh_addr; - mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym); - /* Make sure we get permanent strtab: don't use info->strtab. */ - mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr; - mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs; - - /* - * Now populate the cut down core kallsyms for after init - * and set types up while we still have access to sections. - */ - mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; - mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; - mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs; - src = mod->kallsyms->symtab; - for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { - mod->kallsyms->typetab[i] = elf_type(src + i, info); - if (i == 0 || is_livepatch_module(mod) || - is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, - info->index.pcpu)) { - mod->core_kallsyms.typetab[ndst] = - mod->kallsyms->typetab[i]; - dst[ndst] = src[i]; - dst[ndst++].st_name = s - mod->core_kallsyms.strtab; - s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], - KSYM_NAME_LEN) + 1; - } - } - mod->core_kallsyms.num_symtab = ndst; -} -#else -static inline void layout_symtab(struct module *mod, struct load_info *info) -{ -} - -static void add_kallsyms(struct module *mod, const struct load_info *info) -{ -} -#endif /* CONFIG_KALLSYMS */ - -#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) -static void init_build_id(struct module *mod, const struct load_info *info) -{ - const Elf_Shdr *sechdr; - unsigned int i; - - for (i = 0; i < info->hdr->e_shnum; i++) { - sechdr = &info->sechdrs[i]; - if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE && - !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id, - sechdr->sh_size)) - break; - } -} -#else -static void init_build_id(struct module *mod, const struct load_info *info) -{ -} -#endif - -static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) -{ - if (!debug) - return; - ddebug_add_module(debug, num, mod->name); -} - -static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) -{ - if (debug) - ddebug_remove_module(mod->name); -} - -void * __weak module_alloc(unsigned long size) -{ - return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, - GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, - NUMA_NO_NODE, __builtin_return_address(0)); -} - -bool __weak module_init_section(const char *name) -{ - return strstarts(name, ".init"); -} - -bool __weak module_exit_section(const char *name) -{ - return strstarts(name, ".exit"); -} - -#ifdef CONFIG_DEBUG_KMEMLEAK -static void kmemleak_load_module(const struct module *mod, - const struct load_info *info) -{ - unsigned int i; - - /* only scan the sections containing data */ - kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); - - for (i = 1; i < info->hdr->e_shnum; i++) { - /* Scan all writable sections that's not executable */ - if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) || - !(info->sechdrs[i].sh_flags & SHF_WRITE) || - (info->sechdrs[i].sh_flags & SHF_EXECINSTR)) - continue; - - kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, - info->sechdrs[i].sh_size, GFP_KERNEL); - } -} -#else -static inline void kmemleak_load_module(const struct module *mod, - const struct load_info *info) -{ -} -#endif - -#ifdef CONFIG_MODULE_SIG -static int module_sig_check(struct load_info *info, int flags) -{ - int err = -ENODATA; - const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; - const char *reason; - const void *mod = info->hdr; - bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS | - MODULE_INIT_IGNORE_VERMAGIC); - /* - * Do not allow mangled modules as a module with version information - * removed is no longer the module that was signed. - */ - if (!mangled_module && - info->len > markerlen && - memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { - /* We truncate the module to discard the signature */ - info->len -= markerlen; - err = mod_verify_sig(mod, info); - if (!err) { - info->sig_ok = true; - return 0; - } - } - - /* - * We don't permit modules to be loaded into the trusted kernels - * without a valid signature on them, but if we're not enforcing, - * certain errors are non-fatal. - */ - switch (err) { - case -ENODATA: - reason = "unsigned module"; - break; - case -ENOPKG: - reason = "module with unsupported crypto"; - break; - case -ENOKEY: - reason = "module with unavailable key"; - break; - - default: - /* - * All other errors are fatal, including lack of memory, - * unparseable signatures, and signature check failures -- - * even if signatures aren't required. - */ - return err; - } - - if (is_module_sig_enforced()) { - pr_notice("Loading of %s is rejected\n", reason); - return -EKEYREJECTED; - } - - return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); -} -#else /* !CONFIG_MODULE_SIG */ -static int module_sig_check(struct load_info *info, int flags) -{ - return 0; -} -#endif /* !CONFIG_MODULE_SIG */ - -static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr) -{ -#if defined(CONFIG_64BIT) - unsigned long long secend; -#else - unsigned long secend; -#endif - - /* - * Check for both overflow and offset/size being - * too large. - */ - secend = shdr->sh_offset + shdr->sh_size; - if (secend < shdr->sh_offset || secend > info->len) - return -ENOEXEC; - - return 0; -} - -/* - * Sanity checks against invalid binaries, wrong arch, weird elf version. - * - * Also do basic validity checks against section offsets and sizes, the - * section name string table, and the indices used for it (sh_name). - */ -static int elf_validity_check(struct load_info *info) -{ - unsigned int i; - Elf_Shdr *shdr, *strhdr; - int err; - - if (info->len < sizeof(*(info->hdr))) { - pr_err("Invalid ELF header len %lu\n", info->len); - goto no_exec; - } - - if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) { - pr_err("Invalid ELF header magic: != %s\n", ELFMAG); - goto no_exec; - } - if (info->hdr->e_type != ET_REL) { - pr_err("Invalid ELF header type: %u != %u\n", - info->hdr->e_type, ET_REL); - goto no_exec; - } - if (!elf_check_arch(info->hdr)) { - pr_err("Invalid architecture in ELF header: %u\n", - info->hdr->e_machine); - goto no_exec; - } - if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) { - pr_err("Invalid ELF section header size\n"); - goto no_exec; - } - - /* - * e_shnum is 16 bits, and sizeof(Elf_Shdr) is - * known and small. So e_shnum * sizeof(Elf_Shdr) - * will not overflow unsigned long on any platform. - */ - if (info->hdr->e_shoff >= info->len - || (info->hdr->e_shnum * sizeof(Elf_Shdr) > - info->len - info->hdr->e_shoff)) { - pr_err("Invalid ELF section header overflow\n"); - goto no_exec; - } - - info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; - - /* - * Verify if the section name table index is valid. - */ - if (info->hdr->e_shstrndx == SHN_UNDEF - || info->hdr->e_shstrndx >= info->hdr->e_shnum) { - pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n", - info->hdr->e_shstrndx, info->hdr->e_shstrndx, - info->hdr->e_shnum); - goto no_exec; - } - - strhdr = &info->sechdrs[info->hdr->e_shstrndx]; - err = validate_section_offset(info, strhdr); - if (err < 0) { - pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type); - return err; - } - - /* - * The section name table must be NUL-terminated, as required - * by the spec. This makes strcmp and pr_* calls that access - * strings in the section safe. - */ - info->secstrings = (void *)info->hdr + strhdr->sh_offset; - if (info->secstrings[strhdr->sh_size - 1] != '\0') { - pr_err("ELF Spec violation: section name table isn't null terminated\n"); - goto no_exec; - } - - /* - * The code assumes that section 0 has a length of zero and - * an addr of zero, so check for it. - */ - if (info->sechdrs[0].sh_type != SHT_NULL - || info->sechdrs[0].sh_size != 0 - || info->sechdrs[0].sh_addr != 0) { - pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n", - info->sechdrs[0].sh_type); - goto no_exec; - } - - for (i = 1; i < info->hdr->e_shnum; i++) { - shdr = &info->sechdrs[i]; - switch (shdr->sh_type) { - case SHT_NULL: - case SHT_NOBITS: - continue; - case SHT_SYMTAB: - if (shdr->sh_link == SHN_UNDEF - || shdr->sh_link >= info->hdr->e_shnum) { - pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", - shdr->sh_link, shdr->sh_link, - info->hdr->e_shnum); - goto no_exec; - } - fallthrough; - default: - err = validate_section_offset(info, shdr); - if (err < 0) { - pr_err("Invalid ELF section in module (section %u type %u)\n", - i, shdr->sh_type); - return err; - } - - if (shdr->sh_flags & SHF_ALLOC) { - if (shdr->sh_name >= strhdr->sh_size) { - pr_err("Invalid ELF section name in module (section %u type %u)\n", - i, shdr->sh_type); - return -ENOEXEC; - } - } - break; - } - } - - return 0; - -no_exec: - return -ENOEXEC; -} - -#define COPY_CHUNK_SIZE (16*PAGE_SIZE) - -static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) -{ - do { - unsigned long n = min(len, COPY_CHUNK_SIZE); - - if (copy_from_user(dst, usrc, n) != 0) - return -EFAULT; - cond_resched(); - dst += n; - usrc += n; - len -= n; - } while (len); - return 0; -} - -#ifdef CONFIG_LIVEPATCH -static int check_modinfo_livepatch(struct module *mod, struct load_info *info) -{ - if (get_modinfo(info, "livepatch")) { - mod->klp = true; - add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); - pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", - mod->name); - } - - return 0; -} -#else /* !CONFIG_LIVEPATCH */ -static int check_modinfo_livepatch(struct module *mod, struct load_info *info) -{ - if (get_modinfo(info, "livepatch")) { - pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", - mod->name); - return -ENOEXEC; - } - - return 0; -} -#endif /* CONFIG_LIVEPATCH */ - -static void check_modinfo_retpoline(struct module *mod, struct load_info *info) -{ - if (retpoline_module_ok(get_modinfo(info, "retpoline"))) - return; - - pr_warn("%s: loading module not compiled with retpoline compiler.\n", - mod->name); -} - -/* Sets info->hdr and info->len. */ -static int copy_module_from_user(const void __user *umod, unsigned long len, - struct load_info *info) -{ - int err; - - info->len = len; - if (info->len < sizeof(*(info->hdr))) - return -ENOEXEC; - - err = security_kernel_load_data(LOADING_MODULE, true); - if (err) - return err; - - /* Suck in entire file: we'll want most of it. */ - info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN); - if (!info->hdr) - return -ENOMEM; - - if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { - err = -EFAULT; - goto out; - } - - err = security_kernel_post_load_data((char *)info->hdr, info->len, - LOADING_MODULE, "init_module"); -out: - if (err) - vfree(info->hdr); - - return err; -} - -static void free_copy(struct load_info *info, int flags) -{ - if (flags & MODULE_INIT_COMPRESSED_FILE) - module_decompress_cleanup(info); - else - vfree(info->hdr); -} - -static int rewrite_section_headers(struct load_info *info, int flags) -{ - unsigned int i; - - /* This should always be true, but let's be sure. */ - info->sechdrs[0].sh_addr = 0; - - for (i = 1; i < info->hdr->e_shnum; i++) { - Elf_Shdr *shdr = &info->sechdrs[i]; - - /* - * Mark all sections sh_addr with their address in the - * temporary image. - */ - shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; - - } - - /* Track but don't keep modinfo and version sections. */ - info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; - info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; - - return 0; -} - -/* - * Set up our basic convenience variables (pointers to section headers, - * search for module section index etc), and do some basic section - * verification. - * - * Set info->mod to the temporary copy of the module in info->hdr. The final one - * will be allocated in move_module(). - */ -static int setup_load_info(struct load_info *info, int flags) -{ - unsigned int i; - - /* Try to find a name early so we can log errors with a module name */ - info->index.info = find_sec(info, ".modinfo"); - if (info->index.info) - info->name = get_modinfo(info, "name"); - - /* Find internal symbols and strings. */ - for (i = 1; i < info->hdr->e_shnum; i++) { - if (info->sechdrs[i].sh_type == SHT_SYMTAB) { - info->index.sym = i; - info->index.str = info->sechdrs[i].sh_link; - info->strtab = (char *)info->hdr - + info->sechdrs[info->index.str].sh_offset; - break; - } - } - - if (info->index.sym == 0) { - pr_warn("%s: module has no symbols (stripped?)\n", - info->name ?: "(missing .modinfo section or name field)"); - return -ENOEXEC; - } - - info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); - if (!info->index.mod) { - pr_warn("%s: No module found in object\n", - info->name ?: "(missing .modinfo section or name field)"); - return -ENOEXEC; - } - /* This is temporary: point mod into copy of data. */ - info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset; - - /* - * If we didn't load the .modinfo 'name' field earlier, fall back to - * on-disk struct mod 'name' field. - */ - if (!info->name) - info->name = info->mod->name; - - if (flags & MODULE_INIT_IGNORE_MODVERSIONS) - info->index.vers = 0; /* Pretend no __versions section! */ - else - info->index.vers = find_sec(info, "__versions"); - - info->index.pcpu = find_pcpusec(info); - - return 0; -} - -static int check_modinfo(struct module *mod, struct load_info *info, int flags) -{ - const char *modmagic = get_modinfo(info, "vermagic"); - int err; - - if (flags & MODULE_INIT_IGNORE_VERMAGIC) - modmagic = NULL; - - /* This is allowed: modprobe --force will invalidate it. */ - if (!modmagic) { - err = try_to_force_load(mod, "bad vermagic"); - if (err) - return err; - } else if (!same_magic(modmagic, vermagic, info->index.vers)) { - pr_err("%s: version magic '%s' should be '%s'\n", - info->name, modmagic, vermagic); - return -ENOEXEC; - } - - if (!get_modinfo(info, "intree")) { - if (!test_taint(TAINT_OOT_MODULE)) - pr_warn("%s: loading out-of-tree module taints kernel.\n", - mod->name); - add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); - } - - check_modinfo_retpoline(mod, info); - - if (get_modinfo(info, "staging")) { - add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); - pr_warn("%s: module is from the staging directory, the quality " - "is unknown, you have been warned.\n", mod->name); - } - - err = check_modinfo_livepatch(mod, info); - if (err) - return err; - - /* Set up license info based on the info section */ - set_license(mod, get_modinfo(info, "license")); - - return 0; -} - -static int find_module_sections(struct module *mod, struct load_info *info) -{ - mod->kp = section_objs(info, "__param", - sizeof(*mod->kp), &mod->num_kp); - mod->syms = section_objs(info, "__ksymtab", - sizeof(*mod->syms), &mod->num_syms); - mod->crcs = section_addr(info, "__kcrctab"); - mod->gpl_syms = section_objs(info, "__ksymtab_gpl", - sizeof(*mod->gpl_syms), - &mod->num_gpl_syms); - mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); - -#ifdef CONFIG_CONSTRUCTORS - mod->ctors = section_objs(info, ".ctors", - sizeof(*mod->ctors), &mod->num_ctors); - if (!mod->ctors) - mod->ctors = section_objs(info, ".init_array", - sizeof(*mod->ctors), &mod->num_ctors); - else if (find_sec(info, ".init_array")) { - /* - * This shouldn't happen with same compiler and binutils - * building all parts of the module. - */ - pr_warn("%s: has both .ctors and .init_array.\n", - mod->name); - return -EINVAL; - } -#endif - - mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, - &mod->noinstr_text_size); - -#ifdef CONFIG_TRACEPOINTS - mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", - sizeof(*mod->tracepoints_ptrs), - &mod->num_tracepoints); -#endif -#ifdef CONFIG_TREE_SRCU - mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs", - sizeof(*mod->srcu_struct_ptrs), - &mod->num_srcu_structs); -#endif -#ifdef CONFIG_BPF_EVENTS - mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map", - sizeof(*mod->bpf_raw_events), - &mod->num_bpf_raw_events); -#endif -#ifdef CONFIG_DEBUG_INFO_BTF_MODULES - mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size); -#endif -#ifdef CONFIG_JUMP_LABEL - mod->jump_entries = section_objs(info, "__jump_table", - sizeof(*mod->jump_entries), - &mod->num_jump_entries); -#endif -#ifdef CONFIG_EVENT_TRACING - mod->trace_events = section_objs(info, "_ftrace_events", - sizeof(*mod->trace_events), - &mod->num_trace_events); - mod->trace_evals = section_objs(info, "_ftrace_eval_map", - sizeof(*mod->trace_evals), - &mod->num_trace_evals); -#endif -#ifdef CONFIG_TRACING - mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", - sizeof(*mod->trace_bprintk_fmt_start), - &mod->num_trace_bprintk_fmt); -#endif -#ifdef CONFIG_FTRACE_MCOUNT_RECORD - /* sechdrs[0].sh_size is always zero */ - mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION, - sizeof(*mod->ftrace_callsites), - &mod->num_ftrace_callsites); -#endif -#ifdef CONFIG_FUNCTION_ERROR_INJECTION - mod->ei_funcs = section_objs(info, "_error_injection_whitelist", - sizeof(*mod->ei_funcs), - &mod->num_ei_funcs); -#endif -#ifdef CONFIG_KPROBES - mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, - &mod->kprobes_text_size); - mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", - sizeof(unsigned long), - &mod->num_kprobe_blacklist); -#endif -#ifdef CONFIG_PRINTK_INDEX - mod->printk_index_start = section_objs(info, ".printk_index", - sizeof(*mod->printk_index_start), - &mod->printk_index_size); -#endif -#ifdef CONFIG_HAVE_STATIC_CALL_INLINE - mod->static_call_sites = section_objs(info, ".static_call_sites", - sizeof(*mod->static_call_sites), - &mod->num_static_call_sites); -#endif - mod->extable = section_objs(info, "__ex_table", - sizeof(*mod->extable), &mod->num_exentries); - - if (section_addr(info, "__obsparm")) - pr_warn("%s: Ignoring obsolete parameters\n", mod->name); - - info->debug = section_objs(info, "__dyndbg", - sizeof(*info->debug), &info->num_debug); - - return 0; -} - -static int move_module(struct module *mod, struct load_info *info) -{ - int i; - void *ptr; - - /* Do the allocs. */ - ptr = module_alloc(mod->core_layout.size); - /* - * The pointer to this block is stored in the module structure - * which is inside the block. Just mark it as not being a - * leak. - */ - kmemleak_not_leak(ptr); - if (!ptr) - return -ENOMEM; - - memset(ptr, 0, mod->core_layout.size); - mod->core_layout.base = ptr; - - if (mod->init_layout.size) { - ptr = module_alloc(mod->init_layout.size); - /* - * The pointer to this block is stored in the module structure - * which is inside the block. This block doesn't need to be - * scanned as it contains data and code that will be freed - * after the module is initialized. - */ - kmemleak_ignore(ptr); - if (!ptr) { - module_memfree(mod->core_layout.base); - return -ENOMEM; - } - memset(ptr, 0, mod->init_layout.size); - mod->init_layout.base = ptr; - } else - mod->init_layout.base = NULL; - - /* Transfer each section which specifies SHF_ALLOC */ - pr_debug("final section addresses:\n"); - for (i = 0; i < info->hdr->e_shnum; i++) { - void *dest; - Elf_Shdr *shdr = &info->sechdrs[i]; - - if (!(shdr->sh_flags & SHF_ALLOC)) - continue; - - if (shdr->sh_entsize & INIT_OFFSET_MASK) - dest = mod->init_layout.base - + (shdr->sh_entsize & ~INIT_OFFSET_MASK); - else - dest = mod->core_layout.base + shdr->sh_entsize; - - if (shdr->sh_type != SHT_NOBITS) - memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); - /* Update sh_addr to point to copy in image. */ - shdr->sh_addr = (unsigned long)dest; - pr_debug("\t0x%lx %s\n", - (long)shdr->sh_addr, info->secstrings + shdr->sh_name); - } - - return 0; -} - -static int check_module_license_and_versions(struct module *mod) -{ - int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); - - /* - * ndiswrapper is under GPL by itself, but loads proprietary modules. - * Don't use add_taint_module(), as it would prevent ndiswrapper from - * using GPL-only symbols it needs. - */ - if (strcmp(mod->name, "ndiswrapper") == 0) - add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); - - /* driverloader was caught wrongly pretending to be under GPL */ - if (strcmp(mod->name, "driverloader") == 0) - add_taint_module(mod, TAINT_PROPRIETARY_MODULE, - LOCKDEP_NOW_UNRELIABLE); - - /* lve claims to be GPL but upstream won't provide source */ - if (strcmp(mod->name, "lve") == 0) - add_taint_module(mod, TAINT_PROPRIETARY_MODULE, - LOCKDEP_NOW_UNRELIABLE); - - if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) - pr_warn("%s: module license taints kernel.\n", mod->name); - -#ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !mod->crcs) || - (mod->num_gpl_syms && !mod->gpl_crcs)) { - return try_to_force_load(mod, - "no versions for exported symbols"); - } -#endif - return 0; -} - -static void flush_module_icache(const struct module *mod) -{ - /* - * Flush the instruction cache, since we've played with text. - * Do it before processing of module parameters, so the module - * can provide parameter accessor functions of its own. - */ - if (mod->init_layout.base) - flush_icache_range((unsigned long)mod->init_layout.base, - (unsigned long)mod->init_layout.base - + mod->init_layout.size); - flush_icache_range((unsigned long)mod->core_layout.base, - (unsigned long)mod->core_layout.base + mod->core_layout.size); -} - -int __weak module_frob_arch_sections(Elf_Ehdr *hdr, - Elf_Shdr *sechdrs, - char *secstrings, - struct module *mod) -{ - return 0; -} - -/* module_blacklist is a comma-separated list of module names */ -static char *module_blacklist; -static bool blacklisted(const char *module_name) -{ - const char *p; - size_t len; - - if (!module_blacklist) - return false; - - for (p = module_blacklist; *p; p += len) { - len = strcspn(p, ","); - if (strlen(module_name) == len && !memcmp(module_name, p, len)) - return true; - if (p[len] == ',') - len++; - } - return false; -} -core_param(module_blacklist, module_blacklist, charp, 0400); - -static struct module *layout_and_allocate(struct load_info *info, int flags) -{ - struct module *mod; - unsigned int ndx; - int err; - - err = check_modinfo(info->mod, info, flags); - if (err) - return ERR_PTR(err); - - /* Allow arches to frob section contents and sizes. */ - err = module_frob_arch_sections(info->hdr, info->sechdrs, - info->secstrings, info->mod); - if (err < 0) - return ERR_PTR(err); - - err = module_enforce_rwx_sections(info->hdr, info->sechdrs, - info->secstrings, info->mod); - if (err < 0) - return ERR_PTR(err); - - /* We will do a special allocation for per-cpu sections later. */ - info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; - - /* - * Mark ro_after_init section with SHF_RO_AFTER_INIT so that - * layout_sections() can put it in the right place. - * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. - */ - ndx = find_sec(info, ".data..ro_after_init"); - if (ndx) - info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; - /* - * Mark the __jump_table section as ro_after_init as well: these data - * structures are never modified, with the exception of entries that - * refer to code in the __init section, which are annotated as such - * at module load time. - */ - ndx = find_sec(info, "__jump_table"); - if (ndx) - info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; - - /* - * Determine total sizes, and put offsets in sh_entsize. For now - * this is done generically; there doesn't appear to be any - * special cases for the architectures. - */ - layout_sections(info->mod, info); - layout_symtab(info->mod, info); - - /* Allocate and move to the final place */ - err = move_module(info->mod, info); - if (err) - return ERR_PTR(err); - - /* Module has been copied to its final place now: return it. */ - mod = (void *)info->sechdrs[info->index.mod].sh_addr; - kmemleak_load_module(mod, info); - return mod; -} - -/* mod is no longer valid after this! */ -static void module_deallocate(struct module *mod, struct load_info *info) -{ - percpu_modfree(mod); - module_arch_freeing_init(mod); - module_memfree(mod->init_layout.base); - module_memfree(mod->core_layout.base); -} - -int __weak module_finalize(const Elf_Ehdr *hdr, - const Elf_Shdr *sechdrs, - struct module *me) -{ - return 0; -} - -static int post_relocation(struct module *mod, const struct load_info *info) -{ - /* Sort exception table now relocations are done. */ - sort_extable(mod->extable, mod->extable + mod->num_exentries); - - /* Copy relocated percpu area over. */ - percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, - info->sechdrs[info->index.pcpu].sh_size); - - /* Setup kallsyms-specific fields. */ - add_kallsyms(mod, info); - - /* Arch-specific module finalizing. */ - return module_finalize(info->hdr, info->sechdrs, mod); -} - -/* Is this module of this name done loading? No locks held. */ -static bool finished_loading(const char *name) -{ - struct module *mod; - bool ret; - - /* - * The module_mutex should not be a heavily contended lock; - * if we get the occasional sleep here, we'll go an extra iteration - * in the wait_event_interruptible(), which is harmless. - */ - sched_annotate_sleep(); - mutex_lock(&module_mutex); - mod = find_module_all(name, strlen(name), true); - ret = !mod || mod->state == MODULE_STATE_LIVE; - mutex_unlock(&module_mutex); - - return ret; -} - -/* Call module constructors. */ -static void do_mod_ctors(struct module *mod) -{ -#ifdef CONFIG_CONSTRUCTORS - unsigned long i; - - for (i = 0; i < mod->num_ctors; i++) - mod->ctors[i](); -#endif -} - -/* For freeing module_init on success, in case kallsyms traversing */ -struct mod_initfree { - struct llist_node node; - void *module_init; -}; - -static void do_free_init(struct work_struct *w) -{ - struct llist_node *pos, *n, *list; - struct mod_initfree *initfree; - - list = llist_del_all(&init_free_list); - - synchronize_rcu(); - - llist_for_each_safe(pos, n, list) { - initfree = container_of(pos, struct mod_initfree, node); - module_memfree(initfree->module_init); - kfree(initfree); - } -} - -/* - * This is where the real work happens. - * - * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb - * helper command 'lx-symbols'. - */ -static noinline int do_init_module(struct module *mod) -{ - int ret = 0; - struct mod_initfree *freeinit; - - freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); - if (!freeinit) { - ret = -ENOMEM; - goto fail; - } - freeinit->module_init = mod->init_layout.base; - - do_mod_ctors(mod); - /* Start the module */ - if (mod->init != NULL) - ret = do_one_initcall(mod->init); - if (ret < 0) { - goto fail_free_freeinit; - } - if (ret > 0) { - pr_warn("%s: '%s'->init suspiciously returned %d, it should " - "follow 0/-E convention\n" - "%s: loading module anyway...\n", - __func__, mod->name, ret, __func__); - dump_stack(); - } - - /* Now it's a first class citizen! */ - mod->state = MODULE_STATE_LIVE; - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_LIVE, mod); - - /* Delay uevent until module has finished its init routine */ - kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); - - /* - * We need to finish all async code before the module init sequence - * is done. This has potential to deadlock if synchronous module - * loading is requested from async (which is not allowed!). - * - * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous - * request_module() from async workers") for more details. - */ - if (!mod->async_probe_requested) - async_synchronize_full(); - - ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + - mod->init_layout.size); - mutex_lock(&module_mutex); - /* Drop initial reference. */ - module_put(mod); - trim_init_extable(mod); -#ifdef CONFIG_KALLSYMS - /* Switch to core kallsyms now init is done: kallsyms may be walking! */ - rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); -#endif - module_enable_ro(mod, true); - mod_tree_remove_init(mod); - module_arch_freeing_init(mod); - mod->init_layout.base = NULL; - mod->init_layout.size = 0; - mod->init_layout.ro_size = 0; - mod->init_layout.ro_after_init_size = 0; - mod->init_layout.text_size = 0; -#ifdef CONFIG_DEBUG_INFO_BTF_MODULES - /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */ - mod->btf_data = NULL; -#endif - /* - * We want to free module_init, but be aware that kallsyms may be - * walking this with preempt disabled. In all the failure paths, we - * call synchronize_rcu(), but we don't want to slow down the success - * path. module_memfree() cannot be called in an interrupt, so do the - * work and call synchronize_rcu() in a work queue. - * - * Note that module_alloc() on most architectures creates W+X page - * mappings which won't be cleaned up until do_free_init() runs. Any - * code such as mark_rodata_ro() which depends on those mappings to - * be cleaned up needs to sync with the queued work - ie - * rcu_barrier() - */ - if (llist_add(&freeinit->node, &init_free_list)) - schedule_work(&init_free_wq); - - mutex_unlock(&module_mutex); - wake_up_all(&module_wq); - - return 0; - -fail_free_freeinit: - kfree(freeinit); -fail: - /* Try to protect us from buggy refcounters. */ - mod->state = MODULE_STATE_GOING; - synchronize_rcu(); - module_put(mod); - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_GOING, mod); - klp_module_going(mod); - ftrace_release_mod(mod); - free_module(mod); - wake_up_all(&module_wq); - return ret; -} - -static int may_init_module(void) -{ - if (!capable(CAP_SYS_MODULE) || modules_disabled) - return -EPERM; - - return 0; -} - -/* - * We try to place it in the list now to make sure it's unique before - * we dedicate too many resources. In particular, temporary percpu - * memory exhaustion. - */ -static int add_unformed_module(struct module *mod) -{ - int err; - struct module *old; - - mod->state = MODULE_STATE_UNFORMED; - -again: - mutex_lock(&module_mutex); - old = find_module_all(mod->name, strlen(mod->name), true); - if (old != NULL) { - if (old->state != MODULE_STATE_LIVE) { - /* Wait in case it fails to load. */ - mutex_unlock(&module_mutex); - err = wait_event_interruptible(module_wq, - finished_loading(mod->name)); - if (err) - goto out_unlocked; - goto again; - } - err = -EEXIST; - goto out; - } - mod_update_bounds(mod); - list_add_rcu(&mod->list, &modules); - mod_tree_insert(mod); - err = 0; - -out: - mutex_unlock(&module_mutex); -out_unlocked: - return err; -} - -static int complete_formation(struct module *mod, struct load_info *info) -{ - int err; - - mutex_lock(&module_mutex); - - /* Find duplicate symbols (must be called under lock). */ - err = verify_exported_symbols(mod); - if (err < 0) - goto out; - - /* This relies on module_mutex for list integrity. */ - module_bug_finalize(info->hdr, info->sechdrs, mod); - - module_enable_ro(mod, false); - module_enable_nx(mod); - module_enable_x(mod); - - /* - * Mark state as coming so strong_try_module_get() ignores us, - * but kallsyms etc. can see us. - */ - mod->state = MODULE_STATE_COMING; - mutex_unlock(&module_mutex); - - return 0; - -out: - mutex_unlock(&module_mutex); - return err; -} - -static int prepare_coming_module(struct module *mod) -{ - int err; - - ftrace_module_enable(mod); - err = klp_module_coming(mod); - if (err) - return err; - - err = blocking_notifier_call_chain_robust(&module_notify_list, - MODULE_STATE_COMING, MODULE_STATE_GOING, mod); - err = notifier_to_errno(err); - if (err) - klp_module_going(mod); - - return err; -} - -static int unknown_module_param_cb(char *param, char *val, const char *modname, - void *arg) -{ - struct module *mod = arg; - int ret; - - if (strcmp(param, "async_probe") == 0) { - mod->async_probe_requested = true; - return 0; - } - - /* Check for magic 'dyndbg' arg */ - ret = ddebug_dyndbg_module_param_cb(param, val, modname); - if (ret != 0) - pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); - return 0; -} - -static void cfi_init(struct module *mod); - -/* - * Allocate and load the module: note that size of section 0 is always - * zero, and we rely on this for optional sections. - */ -static int load_module(struct load_info *info, const char __user *uargs, - int flags) -{ - struct module *mod; - long err = 0; - char *after_dashes; - - /* - * Do the signature check (if any) first. All that - * the signature check needs is info->len, it does - * not need any of the section info. That can be - * set up later. This will minimize the chances - * of a corrupt module causing problems before - * we even get to the signature check. - * - * The check will also adjust info->len by stripping - * off the sig length at the end of the module, making - * checks against info->len more correct. - */ - err = module_sig_check(info, flags); - if (err) - goto free_copy; - - /* - * Do basic sanity checks against the ELF header and - * sections. - */ - err = elf_validity_check(info); - if (err) - goto free_copy; - - /* - * Everything checks out, so set up the section info - * in the info structure. - */ - err = setup_load_info(info, flags); - if (err) - goto free_copy; - - /* - * Now that we know we have the correct module name, check - * if it's blacklisted. - */ - if (blacklisted(info->name)) { - err = -EPERM; - pr_err("Module %s is blacklisted\n", info->name); - goto free_copy; - } - - err = rewrite_section_headers(info, flags); - if (err) - goto free_copy; - - /* Check module struct version now, before we try to use module. */ - if (!check_modstruct_version(info, info->mod)) { - err = -ENOEXEC; - goto free_copy; - } - - /* Figure out module layout, and allocate all the memory. */ - mod = layout_and_allocate(info, flags); - if (IS_ERR(mod)) { - err = PTR_ERR(mod); - goto free_copy; - } - - audit_log_kern_module(mod->name); - - /* Reserve our place in the list. */ - err = add_unformed_module(mod); - if (err) - goto free_module; - -#ifdef CONFIG_MODULE_SIG - mod->sig_ok = info->sig_ok; - if (!mod->sig_ok) { - pr_notice_once("%s: module verification failed: signature " - "and/or required key missing - tainting " - "kernel\n", mod->name); - add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); - } -#endif - - /* To avoid stressing percpu allocator, do this once we're unique. */ - err = percpu_modalloc(mod, info); - if (err) - goto unlink_mod; - - /* Now module is in final location, initialize linked lists, etc. */ - err = module_unload_init(mod); - if (err) - goto unlink_mod; - - init_param_lock(mod); - - /* - * Now we've got everything in the final locations, we can - * find optional sections. - */ - err = find_module_sections(mod, info); - if (err) - goto free_unload; - - err = check_module_license_and_versions(mod); - if (err) - goto free_unload; - - /* Set up MODINFO_ATTR fields */ - setup_modinfo(mod, info); - - /* Fix up syms, so that st_value is a pointer to location. */ - err = simplify_symbols(mod, info); - if (err < 0) - goto free_modinfo; - - err = apply_relocations(mod, info); - if (err < 0) - goto free_modinfo; - - err = post_relocation(mod, info); - if (err < 0) - goto free_modinfo; - - flush_module_icache(mod); - - /* Setup CFI for the module. */ - cfi_init(mod); - - /* Now copy in args */ - mod->args = strndup_user(uargs, ~0UL >> 1); - if (IS_ERR(mod->args)) { - err = PTR_ERR(mod->args); - goto free_arch_cleanup; - } - - init_build_id(mod, info); - dynamic_debug_setup(mod, info->debug, info->num_debug); - - /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ - ftrace_module_init(mod); - - /* Finally it's fully formed, ready to start executing. */ - err = complete_formation(mod, info); - if (err) - goto ddebug_cleanup; - - err = prepare_coming_module(mod); - if (err) - goto bug_cleanup; - - /* Module is ready to execute: parsing args may do that. */ - after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, - -32768, 32767, mod, - unknown_module_param_cb); - if (IS_ERR(after_dashes)) { - err = PTR_ERR(after_dashes); - goto coming_cleanup; - } else if (after_dashes) { - pr_warn("%s: parameters '%s' after `--' ignored\n", - mod->name, after_dashes); - } - - /* Link in to sysfs. */ - err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); - if (err < 0) - goto coming_cleanup; - - if (is_livepatch_module(mod)) { - err = copy_module_elf(mod, info); - if (err < 0) - goto sysfs_cleanup; - } - - /* Get rid of temporary copy. */ - free_copy(info, flags); - - /* Done! */ - trace_module_load(mod); - - return do_init_module(mod); - - sysfs_cleanup: - mod_sysfs_teardown(mod); - coming_cleanup: - mod->state = MODULE_STATE_GOING; - destroy_params(mod->kp, mod->num_kp); - blocking_notifier_call_chain(&module_notify_list, - MODULE_STATE_GOING, mod); - klp_module_going(mod); - bug_cleanup: - mod->state = MODULE_STATE_GOING; - /* module_bug_cleanup needs module_mutex protection */ - mutex_lock(&module_mutex); - module_bug_cleanup(mod); - mutex_unlock(&module_mutex); - - ddebug_cleanup: - ftrace_release_mod(mod); - dynamic_debug_remove(mod, info->debug); - synchronize_rcu(); - kfree(mod->args); - free_arch_cleanup: - cfi_cleanup(mod); - module_arch_cleanup(mod); - free_modinfo: - free_modinfo(mod); - free_unload: - module_unload_free(mod); - unlink_mod: - mutex_lock(&module_mutex); - /* Unlink carefully: kallsyms could be walking list. */ - list_del_rcu(&mod->list); - mod_tree_remove(mod); - wake_up_all(&module_wq); - /* Wait for RCU-sched synchronizing before releasing mod->list. */ - synchronize_rcu(); - mutex_unlock(&module_mutex); - free_module: - /* Free lock-classes; relies on the preceding sync_rcu() */ - lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); - - module_deallocate(mod, info); - free_copy: - free_copy(info, flags); - return err; -} - -SYSCALL_DEFINE3(init_module, void __user *, umod, - unsigned long, len, const char __user *, uargs) -{ - int err; - struct load_info info = { }; - - err = may_init_module(); - if (err) - return err; - - pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n", - umod, len, uargs); - - err = copy_module_from_user(umod, len, &info); - if (err) - return err; - - return load_module(&info, uargs, 0); -} - -SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) -{ - struct load_info info = { }; - void *buf = NULL; - int len; - int err; - - err = may_init_module(); - if (err) - return err; - - pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); - - if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS - |MODULE_INIT_IGNORE_VERMAGIC - |MODULE_INIT_COMPRESSED_FILE)) - return -EINVAL; - - len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL, - READING_MODULE); - if (len < 0) - return len; - - if (flags & MODULE_INIT_COMPRESSED_FILE) { - err = module_decompress(&info, buf, len); - vfree(buf); /* compressed data is no longer needed */ - if (err) - return err; - } else { - info.hdr = buf; - info.len = len; - } - - return load_module(&info, uargs, flags); -} - -static inline int within(unsigned long addr, void *start, unsigned long size) -{ - return ((void *)addr >= start && (void *)addr < start + size); -} - -#ifdef CONFIG_KALLSYMS -/* - * This ignores the intensely annoying "mapping symbols" found - * in ARM ELF files: $a, $t and $d. - */ -static inline int is_arm_mapping_symbol(const char *str) -{ - if (str[0] == '.' && str[1] == 'L') - return true; - return str[0] == '$' && strchr("axtd", str[1]) - && (str[2] == '\0' || str[2] == '.'); -} - -static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum) -{ - return kallsyms->strtab + kallsyms->symtab[symnum].st_name; -} - -/* - * Given a module and address, find the corresponding symbol and return its name - * while providing its size and offset if needed. - */ -static const char *find_kallsyms_symbol(struct module *mod, - unsigned long addr, - unsigned long *size, - unsigned long *offset) -{ - unsigned int i, best = 0; - unsigned long nextval, bestval; - struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); - - /* At worse, next value is at end of module */ - if (within_module_init(addr, mod)) - nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size; - else - nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size; - - bestval = kallsyms_symbol_value(&kallsyms->symtab[best]); - - /* - * Scan for closest preceding symbol, and next symbol. (ELF - * starts real symbols at 1). - */ - for (i = 1; i < kallsyms->num_symtab; i++) { - const Elf_Sym *sym = &kallsyms->symtab[i]; - unsigned long thisval = kallsyms_symbol_value(sym); - - if (sym->st_shndx == SHN_UNDEF) - continue; - - /* - * We ignore unnamed symbols: they're uninformative - * and inserted at a whim. - */ - if (*kallsyms_symbol_name(kallsyms, i) == '\0' - || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) - continue; - - if (thisval <= addr && thisval > bestval) { - best = i; - bestval = thisval; - } - if (thisval > addr && thisval < nextval) - nextval = thisval; - } - - if (!best) - return NULL; - - if (size) - *size = nextval - bestval; - if (offset) - *offset = addr - bestval; - - return kallsyms_symbol_name(kallsyms, best); -} - -void * __weak dereference_module_function_descriptor(struct module *mod, - void *ptr) -{ - return ptr; -} - -/* - * For kallsyms to ask for address resolution. NULL means not found. Careful - * not to lock to avoid deadlock on oopses, simply disable preemption. - */ -const char *module_address_lookup(unsigned long addr, - unsigned long *size, - unsigned long *offset, - char **modname, - const unsigned char **modbuildid, - char *namebuf) -{ - const char *ret = NULL; - struct module *mod; - - preempt_disable(); - mod = __module_address(addr); - if (mod) { - if (modname) - *modname = mod->name; - if (modbuildid) { -#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) - *modbuildid = mod->build_id; -#else - *modbuildid = NULL; -#endif - } - - ret = find_kallsyms_symbol(mod, addr, size, offset); - } - /* Make a copy in here where it's safe */ - if (ret) { - strncpy(namebuf, ret, KSYM_NAME_LEN - 1); - ret = namebuf; - } - preempt_enable(); - - return ret; -} - -int lookup_module_symbol_name(unsigned long addr, char *symname) -{ - struct module *mod; - - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (within_module(addr, mod)) { - const char *sym; - - sym = find_kallsyms_symbol(mod, addr, NULL, NULL); - if (!sym) - goto out; - - strlcpy(symname, sym, KSYM_NAME_LEN); - preempt_enable(); - return 0; - } - } -out: - preempt_enable(); - return -ERANGE; -} - -int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, - unsigned long *offset, char *modname, char *name) -{ - struct module *mod; - - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if (within_module(addr, mod)) { - const char *sym; - - sym = find_kallsyms_symbol(mod, addr, size, offset); - if (!sym) - goto out; - if (modname) - strlcpy(modname, mod->name, MODULE_NAME_LEN); - if (name) - strlcpy(name, sym, KSYM_NAME_LEN); - preempt_enable(); - return 0; - } - } -out: - preempt_enable(); - return -ERANGE; -} - -int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, - char *name, char *module_name, int *exported) -{ - struct module *mod; - - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - struct mod_kallsyms *kallsyms; - - if (mod->state == MODULE_STATE_UNFORMED) - continue; - kallsyms = rcu_dereference_sched(mod->kallsyms); - if (symnum < kallsyms->num_symtab) { - const Elf_Sym *sym = &kallsyms->symtab[symnum]; - - *value = kallsyms_symbol_value(sym); - *type = kallsyms->typetab[symnum]; - strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN); - strlcpy(module_name, mod->name, MODULE_NAME_LEN); - *exported = is_exported(name, *value, mod); - preempt_enable(); - return 0; - } - symnum -= kallsyms->num_symtab; - } - preempt_enable(); - return -ERANGE; -} - -/* Given a module and name of symbol, find and return the symbol's value */ -static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name) -{ - unsigned int i; - struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); - - for (i = 0; i < kallsyms->num_symtab; i++) { - const Elf_Sym *sym = &kallsyms->symtab[i]; - - if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 && - sym->st_shndx != SHN_UNDEF) - return kallsyms_symbol_value(sym); - } - return 0; -} - -/* Look for this name: can be of form module:name. */ -unsigned long module_kallsyms_lookup_name(const char *name) -{ - struct module *mod; - char *colon; - unsigned long ret = 0; - - /* Don't lock: we're in enough trouble already. */ - preempt_disable(); - if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) { - if ((mod = find_module_all(name, colon - name, false)) != NULL) - ret = find_kallsyms_symbol_value(mod, colon+1); - } else { - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - if ((ret = find_kallsyms_symbol_value(mod, name)) != 0) - break; - } - } - preempt_enable(); - return ret; -} - -#ifdef CONFIG_LIVEPATCH -int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, - struct module *, unsigned long), - void *data) -{ - struct module *mod; - unsigned int i; - int ret = 0; - - mutex_lock(&module_mutex); - list_for_each_entry(mod, &modules, list) { - /* We hold module_mutex: no need for rcu_dereference_sched */ - struct mod_kallsyms *kallsyms = mod->kallsyms; - - if (mod->state == MODULE_STATE_UNFORMED) - continue; - for (i = 0; i < kallsyms->num_symtab; i++) { - const Elf_Sym *sym = &kallsyms->symtab[i]; - - if (sym->st_shndx == SHN_UNDEF) - continue; - - ret = fn(data, kallsyms_symbol_name(kallsyms, i), - mod, kallsyms_symbol_value(sym)); - if (ret != 0) - goto out; - - cond_resched(); - } - } -out: - mutex_unlock(&module_mutex); - return ret; -} -#endif /* CONFIG_LIVEPATCH */ -#endif /* CONFIG_KALLSYMS */ - -static void cfi_init(struct module *mod) -{ -#ifdef CONFIG_CFI_CLANG - initcall_t *init; - exitcall_t *exit; - - rcu_read_lock_sched(); - mod->cfi_check = (cfi_check_fn) - find_kallsyms_symbol_value(mod, "__cfi_check"); - init = (initcall_t *) - find_kallsyms_symbol_value(mod, "__cfi_jt_init_module"); - exit = (exitcall_t *) - find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module"); - rcu_read_unlock_sched(); - - /* Fix init/exit functions to point to the CFI jump table */ - if (init) - mod->init = *init; -#ifdef CONFIG_MODULE_UNLOAD - if (exit) - mod->exit = *exit; -#endif - - cfi_module_add(mod, module_addr_min); -#endif -} - -static void cfi_cleanup(struct module *mod) -{ -#ifdef CONFIG_CFI_CLANG - cfi_module_remove(mod, module_addr_min); -#endif -} - -/* Maximum number of characters written by module_flags() */ -#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) - -/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ -static char *module_flags(struct module *mod, char *buf) -{ - int bx = 0; - - BUG_ON(mod->state == MODULE_STATE_UNFORMED); - if (mod->taints || - mod->state == MODULE_STATE_GOING || - mod->state == MODULE_STATE_COMING) { - buf[bx++] = '('; - bx += module_flags_taint(mod, buf + bx); - /* Show a - for module-is-being-unloaded */ - if (mod->state == MODULE_STATE_GOING) - buf[bx++] = '-'; - /* Show a + for module-is-being-loaded */ - if (mod->state == MODULE_STATE_COMING) - buf[bx++] = '+'; - buf[bx++] = ')'; - } - buf[bx] = '\0'; - - return buf; -} - -#ifdef CONFIG_PROC_FS -/* Called by the /proc file system to return a list of modules. */ -static void *m_start(struct seq_file *m, loff_t *pos) -{ - mutex_lock(&module_mutex); - return seq_list_start(&modules, *pos); -} - -static void *m_next(struct seq_file *m, void *p, loff_t *pos) -{ - return seq_list_next(p, &modules, pos); -} - -static void m_stop(struct seq_file *m, void *p) -{ - mutex_unlock(&module_mutex); -} - -static int m_show(struct seq_file *m, void *p) -{ - struct module *mod = list_entry(p, struct module, list); - char buf[MODULE_FLAGS_BUF_SIZE]; - void *value; - - /* We always ignore unformed modules. */ - if (mod->state == MODULE_STATE_UNFORMED) - return 0; - - seq_printf(m, "%s %u", - mod->name, mod->init_layout.size + mod->core_layout.size); - print_unload_info(m, mod); - - /* Informative for users. */ - seq_printf(m, " %s", - mod->state == MODULE_STATE_GOING ? "Unloading" : - mod->state == MODULE_STATE_COMING ? "Loading" : - "Live"); - /* Used by oprofile and other similar tools. */ - value = m->private ? NULL : mod->core_layout.base; - seq_printf(m, " 0x%px", value); - - /* Taints info */ - if (mod->taints) - seq_printf(m, " %s", module_flags(mod, buf)); - - seq_puts(m, "\n"); - return 0; -} - -/* - * Format: modulename size refcount deps address - * - * Where refcount is a number or -, and deps is a comma-separated list - * of depends or -. - */ -static const struct seq_operations modules_op = { - .start = m_start, - .next = m_next, - .stop = m_stop, - .show = m_show -}; - -/* - * This also sets the "private" pointer to non-NULL if the - * kernel pointers should be hidden (so you can just test - * "m->private" to see if you should keep the values private). - * - * We use the same logic as for /proc/kallsyms. - */ -static int modules_open(struct inode *inode, struct file *file) -{ - int err = seq_open(file, &modules_op); - - if (!err) { - struct seq_file *m = file->private_data; - m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul; - } - - return err; -} - -static const struct proc_ops modules_proc_ops = { - .proc_flags = PROC_ENTRY_PERMANENT, - .proc_open = modules_open, - .proc_read = seq_read, - .proc_lseek = seq_lseek, - .proc_release = seq_release, -}; - -static int __init proc_modules_init(void) -{ - proc_create("modules", 0, NULL, &modules_proc_ops); - return 0; -} -module_init(proc_modules_init); -#endif - -/* Given an address, look for it in the module exception tables. */ -const struct exception_table_entry *search_module_extables(unsigned long addr) -{ - const struct exception_table_entry *e = NULL; - struct module *mod; - - preempt_disable(); - mod = __module_address(addr); - if (!mod) - goto out; - - if (!mod->num_exentries) - goto out; - - e = search_extable(mod->extable, - mod->num_exentries, - addr); -out: - preempt_enable(); - - /* - * Now, if we found one, we are running inside it now, hence - * we cannot unload the module, hence no refcnt needed. - */ - return e; -} - -/** - * is_module_address() - is this address inside a module? - * @addr: the address to check. - * - * See is_module_text_address() if you simply want to see if the address - * is code (not data). - */ -bool is_module_address(unsigned long addr) -{ - bool ret; - - preempt_disable(); - ret = __module_address(addr) != NULL; - preempt_enable(); - - return ret; -} - -/** - * __module_address() - get the module which contains an address. - * @addr: the address. - * - * Must be called with preempt disabled or module mutex held so that - * module doesn't get freed during this. - */ -struct module *__module_address(unsigned long addr) -{ - struct module *mod; - - if (addr < module_addr_min || addr > module_addr_max) - return NULL; - - module_assert_mutex_or_preempt(); - - mod = mod_find(addr); - if (mod) { - BUG_ON(!within_module(addr, mod)); - if (mod->state == MODULE_STATE_UNFORMED) - mod = NULL; - } - return mod; -} - -/** - * is_module_text_address() - is this address inside module code? - * @addr: the address to check. - * - * See is_module_address() if you simply want to see if the address is - * anywhere in a module. See kernel_text_address() for testing if an - * address corresponds to kernel or module code. - */ -bool is_module_text_address(unsigned long addr) -{ - bool ret; - - preempt_disable(); - ret = __module_text_address(addr) != NULL; - preempt_enable(); - - return ret; -} - -/** - * __module_text_address() - get the module whose code contains an address. - * @addr: the address. - * - * Must be called with preempt disabled or module mutex held so that - * module doesn't get freed during this. - */ -struct module *__module_text_address(unsigned long addr) -{ - struct module *mod = __module_address(addr); - if (mod) { - /* Make sure it's within the text section. */ - if (!within(addr, mod->init_layout.base, mod->init_layout.text_size) - && !within(addr, mod->core_layout.base, mod->core_layout.text_size)) - mod = NULL; - } - return mod; -} - -/* Don't grab lock, we're oopsing. */ -void print_modules(void) -{ - struct module *mod; - char buf[MODULE_FLAGS_BUF_SIZE]; - - printk(KERN_DEFAULT "Modules linked in:"); - /* Most callers should already have preempt disabled, but make sure */ - preempt_disable(); - list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) - continue; - pr_cont(" %s%s", mod->name, module_flags(mod, buf)); - } - preempt_enable(); - if (last_unloaded_module[0]) - pr_cont(" [last unloaded: %s]", last_unloaded_module); - pr_cont("\n"); -} - -#ifdef CONFIG_MODVERSIONS -/* - * Generate the signature for all relevant module structures here. - * If these change, we don't want to try to parse the module. - */ -void module_layout(struct module *mod, - struct modversion_info *ver, - struct kernel_param *kp, - struct kernel_symbol *ks, - struct tracepoint * const *tp) -{ -} -EXPORT_SYMBOL(module_layout); -#endif diff --git a/kernel/module/Makefile b/kernel/module/Makefile new file mode 100644 index 0000000000000..cdd5c61b8c7ff --- /dev/null +++ b/kernel/module/Makefile @@ -0,0 +1,12 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Makefile for linux kernel module support +# + +# These are called from save_stack_trace() on slub debug path, +# and produce insane amounts of uninteresting coverage. +KCOV_INSTRUMENT_module.o := n + +obj-y += main.o +obj-$(CONFIG_MODULE_DECOMPRESS) += decompress.o +obj-$(CONFIG_MODULE_SIG) += signing.o diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c new file mode 100644 index 0000000000000..d14d6443225a2 --- /dev/null +++ b/kernel/module/decompress.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2021 Google LLC. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +static int module_extend_max_pages(struct load_info *info, unsigned int extent) +{ + struct page **new_pages; + + new_pages = kvmalloc_array(info->max_pages + extent, + sizeof(info->pages), GFP_KERNEL); + if (!new_pages) + return -ENOMEM; + + memcpy(new_pages, info->pages, info->max_pages * sizeof(info->pages)); + kvfree(info->pages); + info->pages = new_pages; + info->max_pages += extent; + + return 0; +} + +static struct page *module_get_next_page(struct load_info *info) +{ + struct page *page; + int error; + + if (info->max_pages == info->used_pages) { + error = module_extend_max_pages(info, info->used_pages); + if (error) + return ERR_PTR(error); + } + + page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); + if (!page) + return ERR_PTR(-ENOMEM); + + info->pages[info->used_pages++] = page; + return page; +} + +#ifdef CONFIG_MODULE_COMPRESS_GZIP +#include +#define MODULE_COMPRESSION gzip +#define MODULE_DECOMPRESS_FN module_gzip_decompress + +/* + * Calculate length of the header which consists of signature, header + * flags, time stamp and operating system ID (10 bytes total), plus + * an optional filename. + */ +static size_t module_gzip_header_len(const u8 *buf, size_t size) +{ + const u8 signature[] = { 0x1f, 0x8b, 0x08 }; + size_t len = 10; + + if (size < len || memcmp(buf, signature, sizeof(signature))) + return 0; + + if (buf[3] & 0x08) { + do { + /* + * If we can't find the end of the file name we must + * be dealing with a corrupted file. + */ + if (len == size) + return 0; + } while (buf[len++] != '\0'); + } + + return len; +} + +static ssize_t module_gzip_decompress(struct load_info *info, + const void *buf, size_t size) +{ + struct z_stream_s s = { 0 }; + size_t new_size = 0; + size_t gzip_hdr_len; + ssize_t retval; + int rc; + + gzip_hdr_len = module_gzip_header_len(buf, size); + if (!gzip_hdr_len) { + pr_err("not a gzip compressed module\n"); + return -EINVAL; + } + + s.next_in = buf + gzip_hdr_len; + s.avail_in = size - gzip_hdr_len; + + s.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); + if (!s.workspace) + return -ENOMEM; + + rc = zlib_inflateInit2(&s, -MAX_WBITS); + if (rc != Z_OK) { + pr_err("failed to initialize decompressor: %d\n", rc); + retval = -EINVAL; + goto out; + } + + do { + struct page *page = module_get_next_page(info); + if (!page) { + retval = -ENOMEM; + goto out_inflate_end; + } + + s.next_out = kmap(page); + s.avail_out = PAGE_SIZE; + rc = zlib_inflate(&s, 0); + kunmap(page); + + new_size += PAGE_SIZE - s.avail_out; + } while (rc == Z_OK); + + if (rc != Z_STREAM_END) { + pr_err("decompression failed with status %d\n", rc); + retval = -EINVAL; + goto out_inflate_end; + } + + retval = new_size; + +out_inflate_end: + zlib_inflateEnd(&s); +out: + kfree(s.workspace); + return retval; +} +#elif CONFIG_MODULE_COMPRESS_XZ +#include +#define MODULE_COMPRESSION xz +#define MODULE_DECOMPRESS_FN module_xz_decompress + +static ssize_t module_xz_decompress(struct load_info *info, + const void *buf, size_t size) +{ + static const u8 signature[] = { 0xfd, '7', 'z', 'X', 'Z', 0 }; + struct xz_dec *xz_dec; + struct xz_buf xz_buf; + enum xz_ret xz_ret; + size_t new_size = 0; + ssize_t retval; + + if (size < sizeof(signature) || + memcmp(buf, signature, sizeof(signature))) { + pr_err("not an xz compressed module\n"); + return -EINVAL; + } + + xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1); + if (!xz_dec) + return -ENOMEM; + + xz_buf.in_size = size; + xz_buf.in = buf; + xz_buf.in_pos = 0; + + do { + struct page *page = module_get_next_page(info); + if (!page) { + retval = -ENOMEM; + goto out; + } + + xz_buf.out = kmap(page); + xz_buf.out_pos = 0; + xz_buf.out_size = PAGE_SIZE; + xz_ret = xz_dec_run(xz_dec, &xz_buf); + kunmap(page); + + new_size += xz_buf.out_pos; + } while (xz_buf.out_pos == PAGE_SIZE && xz_ret == XZ_OK); + + if (xz_ret != XZ_STREAM_END) { + pr_err("decompression failed with status %d\n", xz_ret); + retval = -EINVAL; + goto out; + } + + retval = new_size; + + out: + xz_dec_end(xz_dec); + return retval; +} +#else +#error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS" +#endif + +int module_decompress(struct load_info *info, const void *buf, size_t size) +{ + unsigned int n_pages; + ssize_t data_size; + int error; + + /* + * Start with number of pages twice as big as needed for + * compressed data. + */ + n_pages = DIV_ROUND_UP(size, PAGE_SIZE) * 2; + error = module_extend_max_pages(info, n_pages); + + data_size = MODULE_DECOMPRESS_FN(info, buf, size); + if (data_size < 0) { + error = data_size; + goto err; + } + + info->hdr = vmap(info->pages, info->used_pages, VM_MAP, PAGE_KERNEL); + if (!info->hdr) { + error = -ENOMEM; + goto err; + } + + info->len = data_size; + return 0; + +err: + module_decompress_cleanup(info); + return error; +} + +void module_decompress_cleanup(struct load_info *info) +{ + int i; + + if (info->hdr) + vunmap(info->hdr); + + for (i = 0; i < info->used_pages; i++) + __free_page(info->pages[i]); + + kvfree(info->pages); + + info->pages = NULL; + info->max_pages = info->used_pages = 0; +} + +#ifdef CONFIG_SYSFS +static ssize_t compression_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%s\n", __stringify(MODULE_COMPRESSION)); +} +static struct kobj_attribute module_compression_attr = __ATTR_RO(compression); + +static int __init module_decompress_sysfs_init(void) +{ + int error; + + error = sysfs_create_file(&module_kset->kobj, + &module_compression_attr.attr); + if (error) + pr_warn("Failed to create 'compression' attribute"); + + return 0; +} +late_initcall(module_decompress_sysfs_init); +#endif diff --git a/kernel/module/internal.h b/kernel/module/internal.h new file mode 100644 index 0000000000000..8c381c99062f2 --- /dev/null +++ b/kernel/module/internal.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Module internals + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include + +struct load_info { + const char *name; + /* pointer to module in temporary copy, freed at end of load_module() */ + struct module *mod; + Elf_Ehdr *hdr; + unsigned long len; + Elf_Shdr *sechdrs; + char *secstrings, *strtab; + unsigned long symoffs, stroffs, init_typeoffs, core_typeoffs; + struct _ddebug *debug; + unsigned int num_debug; + bool sig_ok; +#ifdef CONFIG_KALLSYMS + unsigned long mod_kallsyms_init_off; +#endif +#ifdef CONFIG_MODULE_DECOMPRESS + struct page **pages; + unsigned int max_pages; + unsigned int used_pages; +#endif + struct { + unsigned int sym, str, mod, vers, info, pcpu; + } index; +}; + +extern int mod_verify_sig(const void *mod, struct load_info *info); + +#ifdef CONFIG_MODULE_DECOMPRESS +int module_decompress(struct load_info *info, const void *buf, size_t size); +void module_decompress_cleanup(struct load_info *info); +#else +static inline int module_decompress(struct load_info *info, + const void *buf, size_t size) +{ + return -EOPNOTSUPP; +} +static inline void module_decompress_cleanup(struct load_info *info) +{ +} +#endif diff --git a/kernel/module/main.c b/kernel/module/main.c new file mode 100644 index 0000000000000..1a17f02f69a01 --- /dev/null +++ b/kernel/module/main.c @@ -0,0 +1,4810 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2002 Richard Henderson + * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM. + */ + +#define INCLUDE_VERMAGIC + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "internal.h" + +#define CREATE_TRACE_POINTS +#include + +#ifndef ARCH_SHF_SMALL +#define ARCH_SHF_SMALL 0 +#endif + +/* + * Modules' sections will be aligned on page boundaries + * to ensure complete separation of code and data, but + * only when CONFIG_ARCH_HAS_STRICT_MODULE_RWX=y + */ +#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX +# define debug_align(X) ALIGN(X, PAGE_SIZE) +#else +# define debug_align(X) (X) +#endif + +/* If this is set, the section belongs in the init part of the module */ +#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) + +/* + * Mutex protects: + * 1) List of modules (also safely readable with preempt_disable), + * 2) module_use links, + * 3) module_addr_min/module_addr_max. + * (delete and add uses RCU list operations). + */ +static DEFINE_MUTEX(module_mutex); +static LIST_HEAD(modules); + +/* Work queue for freeing init sections in success case */ +static void do_free_init(struct work_struct *w); +static DECLARE_WORK(init_free_wq, do_free_init); +static LLIST_HEAD(init_free_list); + +#ifdef CONFIG_MODULES_TREE_LOOKUP + +/* + * Use a latched RB-tree for __module_address(); this allows us to use + * RCU-sched lookups of the address from any context. + * + * This is conditional on PERF_EVENTS || TRACING because those can really hit + * __module_address() hard by doing a lot of stack unwinding; potentially from + * NMI context. + */ + +static __always_inline unsigned long __mod_tree_val(struct latch_tree_node *n) +{ + struct module_layout *layout = container_of(n, struct module_layout, mtn.node); + + return (unsigned long)layout->base; +} + +static __always_inline unsigned long __mod_tree_size(struct latch_tree_node *n) +{ + struct module_layout *layout = container_of(n, struct module_layout, mtn.node); + + return (unsigned long)layout->size; +} + +static __always_inline bool +mod_tree_less(struct latch_tree_node *a, struct latch_tree_node *b) +{ + return __mod_tree_val(a) < __mod_tree_val(b); +} + +static __always_inline int +mod_tree_comp(void *key, struct latch_tree_node *n) +{ + unsigned long val = (unsigned long)key; + unsigned long start, end; + + start = __mod_tree_val(n); + if (val < start) + return -1; + + end = start + __mod_tree_size(n); + if (val >= end) + return 1; + + return 0; +} + +static const struct latch_tree_ops mod_tree_ops = { + .less = mod_tree_less, + .comp = mod_tree_comp, +}; + +static struct mod_tree_root { + struct latch_tree_root root; + unsigned long addr_min; + unsigned long addr_max; +} mod_tree __cacheline_aligned = { + .addr_min = -1UL, +}; + +#define module_addr_min mod_tree.addr_min +#define module_addr_max mod_tree.addr_max + +static noinline void __mod_tree_insert(struct mod_tree_node *node) +{ + latch_tree_insert(&node->node, &mod_tree.root, &mod_tree_ops); +} + +static void __mod_tree_remove(struct mod_tree_node *node) +{ + latch_tree_erase(&node->node, &mod_tree.root, &mod_tree_ops); +} + +/* + * These modifications: insert, remove_init and remove; are serialized by the + * module_mutex. + */ +static void mod_tree_insert(struct module *mod) +{ + mod->core_layout.mtn.mod = mod; + mod->init_layout.mtn.mod = mod; + + __mod_tree_insert(&mod->core_layout.mtn); + if (mod->init_layout.size) + __mod_tree_insert(&mod->init_layout.mtn); +} + +static void mod_tree_remove_init(struct module *mod) +{ + if (mod->init_layout.size) + __mod_tree_remove(&mod->init_layout.mtn); +} + +static void mod_tree_remove(struct module *mod) +{ + __mod_tree_remove(&mod->core_layout.mtn); + mod_tree_remove_init(mod); +} + +static struct module *mod_find(unsigned long addr) +{ + struct latch_tree_node *ltn; + + ltn = latch_tree_find((void *)addr, &mod_tree.root, &mod_tree_ops); + if (!ltn) + return NULL; + + return container_of(ltn, struct mod_tree_node, node)->mod; +} + +#else /* MODULES_TREE_LOOKUP */ + +static unsigned long module_addr_min = -1UL, module_addr_max = 0; + +static void mod_tree_insert(struct module *mod) { } +static void mod_tree_remove_init(struct module *mod) { } +static void mod_tree_remove(struct module *mod) { } + +static struct module *mod_find(unsigned long addr) +{ + struct module *mod; + + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { + if (within_module(addr, mod)) + return mod; + } + + return NULL; +} + +#endif /* MODULES_TREE_LOOKUP */ + +/* + * Bounds of module text, for speeding up __module_address. + * Protected by module_mutex. + */ +static void __mod_update_bounds(void *base, unsigned int size) +{ + unsigned long min = (unsigned long)base; + unsigned long max = min + size; + + if (min < module_addr_min) + module_addr_min = min; + if (max > module_addr_max) + module_addr_max = max; +} + +static void mod_update_bounds(struct module *mod) +{ + __mod_update_bounds(mod->core_layout.base, mod->core_layout.size); + if (mod->init_layout.size) + __mod_update_bounds(mod->init_layout.base, mod->init_layout.size); +} + +#ifdef CONFIG_KGDB_KDB +struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ +#endif /* CONFIG_KGDB_KDB */ + +static void module_assert_mutex_or_preempt(void) +{ +#ifdef CONFIG_LOCKDEP + if (unlikely(!debug_locks)) + return; + + WARN_ON_ONCE(!rcu_read_lock_sched_held() && + !lockdep_is_held(&module_mutex)); +#endif +} + +#ifdef CONFIG_MODULE_SIG +static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE); +module_param(sig_enforce, bool_enable_only, 0644); + +void set_module_sig_enforced(void) +{ + sig_enforce = true; +} +#else +#define sig_enforce false +#endif + +/* + * Export sig_enforce kernel cmdline parameter to allow other subsystems rely + * on that instead of directly to CONFIG_MODULE_SIG_FORCE config. + */ +bool is_module_sig_enforced(void) +{ + return sig_enforce; +} +EXPORT_SYMBOL(is_module_sig_enforced); + +/* Block module loading/unloading? */ +int modules_disabled = 0; +core_param(nomodule, modules_disabled, bint, 0); + +/* Waiting for a module to finish initializing? */ +static DECLARE_WAIT_QUEUE_HEAD(module_wq); + +static BLOCKING_NOTIFIER_HEAD(module_notify_list); + +int register_module_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&module_notify_list, nb); +} +EXPORT_SYMBOL(register_module_notifier); + +int unregister_module_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&module_notify_list, nb); +} +EXPORT_SYMBOL(unregister_module_notifier); + +/* + * We require a truly strong try_module_get(): 0 means success. + * Otherwise an error is returned due to ongoing or failed + * initialization etc. + */ +static inline int strong_try_module_get(struct module *mod) +{ + BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); + if (mod && mod->state == MODULE_STATE_COMING) + return -EBUSY; + if (try_module_get(mod)) + return 0; + else + return -ENOENT; +} + +static inline void add_taint_module(struct module *mod, unsigned flag, + enum lockdep_ok lockdep_ok) +{ + add_taint(flag, lockdep_ok); + set_bit(flag, &mod->taints); +} + +/* + * A thread that wants to hold a reference to a module only while it + * is running can call this to safely exit. + */ +void __noreturn __module_put_and_kthread_exit(struct module *mod, long code) +{ + module_put(mod); + kthread_exit(code); +} +EXPORT_SYMBOL(__module_put_and_kthread_exit); + +/* Find a module section: 0 means not found. */ +static unsigned int find_sec(const struct load_info *info, const char *name) +{ + unsigned int i; + + for (i = 1; i < info->hdr->e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + /* Alloc bit cleared means "ignore it." */ + if ((shdr->sh_flags & SHF_ALLOC) + && strcmp(info->secstrings + shdr->sh_name, name) == 0) + return i; + } + return 0; +} + +/* Find a module section, or NULL. */ +static void *section_addr(const struct load_info *info, const char *name) +{ + /* Section 0 has sh_addr 0. */ + return (void *)info->sechdrs[find_sec(info, name)].sh_addr; +} + +/* Find a module section, or NULL. Fill in number of "objects" in section. */ +static void *section_objs(const struct load_info *info, + const char *name, + size_t object_size, + unsigned int *num) +{ + unsigned int sec = find_sec(info, name); + + /* Section 0 has sh_addr 0 and sh_size 0. */ + *num = info->sechdrs[sec].sh_size / object_size; + return (void *)info->sechdrs[sec].sh_addr; +} + +/* Find a module section: 0 means not found. Ignores SHF_ALLOC flag. */ +static unsigned int find_any_sec(const struct load_info *info, const char *name) +{ + unsigned int i; + + for (i = 1; i < info->hdr->e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + if (strcmp(info->secstrings + shdr->sh_name, name) == 0) + return i; + } + return 0; +} + +/* + * Find a module section, or NULL. Fill in number of "objects" in section. + * Ignores SHF_ALLOC flag. + */ +static __maybe_unused void *any_section_objs(const struct load_info *info, + const char *name, + size_t object_size, + unsigned int *num) +{ + unsigned int sec = find_any_sec(info, name); + + /* Section 0 has sh_addr 0 and sh_size 0. */ + *num = info->sechdrs[sec].sh_size / object_size; + return (void *)info->sechdrs[sec].sh_addr; +} + +/* Provided by the linker */ +extern const struct kernel_symbol __start___ksymtab[]; +extern const struct kernel_symbol __stop___ksymtab[]; +extern const struct kernel_symbol __start___ksymtab_gpl[]; +extern const struct kernel_symbol __stop___ksymtab_gpl[]; +extern const s32 __start___kcrctab[]; +extern const s32 __start___kcrctab_gpl[]; + +#ifndef CONFIG_MODVERSIONS +#define symversion(base, idx) NULL +#else +#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) +#endif + +struct symsearch { + const struct kernel_symbol *start, *stop; + const s32 *crcs; + enum mod_license { + NOT_GPL_ONLY, + GPL_ONLY, + } license; +}; + +struct find_symbol_arg { + /* Input */ + const char *name; + bool gplok; + bool warn; + + /* Output */ + struct module *owner; + const s32 *crc; + const struct kernel_symbol *sym; + enum mod_license license; +}; + +static bool check_exported_symbol(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) +{ + struct find_symbol_arg *fsa = data; + + if (!fsa->gplok && syms->license == GPL_ONLY) + return false; + fsa->owner = owner; + fsa->crc = symversion(syms->crcs, symnum); + fsa->sym = &syms->start[symnum]; + fsa->license = syms->license; + return true; +} + +static unsigned long kernel_symbol_value(const struct kernel_symbol *sym) +{ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + return (unsigned long)offset_to_ptr(&sym->value_offset); +#else + return sym->value; +#endif +} + +static const char *kernel_symbol_name(const struct kernel_symbol *sym) +{ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + return offset_to_ptr(&sym->name_offset); +#else + return sym->name; +#endif +} + +static const char *kernel_symbol_namespace(const struct kernel_symbol *sym) +{ +#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS + if (!sym->namespace_offset) + return NULL; + return offset_to_ptr(&sym->namespace_offset); +#else + return sym->namespace; +#endif +} + +static int cmp_name(const void *name, const void *sym) +{ + return strcmp(name, kernel_symbol_name(sym)); +} + +static bool find_exported_symbol_in_section(const struct symsearch *syms, + struct module *owner, + void *data) +{ + struct find_symbol_arg *fsa = data; + struct kernel_symbol *sym; + + sym = bsearch(fsa->name, syms->start, syms->stop - syms->start, + sizeof(struct kernel_symbol), cmp_name); + + if (sym != NULL && check_exported_symbol(syms, owner, + sym - syms->start, data)) + return true; + + return false; +} + +/* + * Find an exported symbol and return it, along with, (optional) crc and + * (optional) module which owns it. Needs preempt disabled or module_mutex. + */ +static bool find_symbol(struct find_symbol_arg *fsa) +{ + static const struct symsearch arr[] = { + { __start___ksymtab, __stop___ksymtab, __start___kcrctab, + NOT_GPL_ONLY }, + { __start___ksymtab_gpl, __stop___ksymtab_gpl, + __start___kcrctab_gpl, + GPL_ONLY }, + }; + struct module *mod; + unsigned int i; + + module_assert_mutex_or_preempt(); + + for (i = 0; i < ARRAY_SIZE(arr); i++) + if (find_exported_symbol_in_section(&arr[i], NULL, fsa)) + return true; + + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { + struct symsearch arr[] = { + { mod->syms, mod->syms + mod->num_syms, mod->crcs, + NOT_GPL_ONLY }, + { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, + mod->gpl_crcs, + GPL_ONLY }, + }; + + if (mod->state == MODULE_STATE_UNFORMED) + continue; + + for (i = 0; i < ARRAY_SIZE(arr); i++) + if (find_exported_symbol_in_section(&arr[i], mod, fsa)) + return true; + } + + pr_debug("Failed to find symbol %s\n", fsa->name); + return false; +} + +/* + * Search for module by name: must hold module_mutex (or preempt disabled + * for read-only access). + */ +static struct module *find_module_all(const char *name, size_t len, + bool even_unformed) +{ + struct module *mod; + + module_assert_mutex_or_preempt(); + + list_for_each_entry_rcu(mod, &modules, list, + lockdep_is_held(&module_mutex)) { + if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) + continue; + if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) + return mod; + } + return NULL; +} + +struct module *find_module(const char *name) +{ + return find_module_all(name, strlen(name), false); +} + +#ifdef CONFIG_SMP + +static inline void __percpu *mod_percpu(struct module *mod) +{ + return mod->percpu; +} + +static int percpu_modalloc(struct module *mod, struct load_info *info) +{ + Elf_Shdr *pcpusec = &info->sechdrs[info->index.pcpu]; + unsigned long align = pcpusec->sh_addralign; + + if (!pcpusec->sh_size) + return 0; + + if (align > PAGE_SIZE) { + pr_warn("%s: per-cpu alignment %li > %li\n", + mod->name, align, PAGE_SIZE); + align = PAGE_SIZE; + } + + mod->percpu = __alloc_reserved_percpu(pcpusec->sh_size, align); + if (!mod->percpu) { + pr_warn("%s: Could not allocate %lu bytes percpu data\n", + mod->name, (unsigned long)pcpusec->sh_size); + return -ENOMEM; + } + mod->percpu_size = pcpusec->sh_size; + return 0; +} + +static void percpu_modfree(struct module *mod) +{ + free_percpu(mod->percpu); +} + +static unsigned int find_pcpusec(struct load_info *info) +{ + return find_sec(info, ".data..percpu"); +} + +static void percpu_modcopy(struct module *mod, + const void *from, unsigned long size) +{ + int cpu; + + for_each_possible_cpu(cpu) + memcpy(per_cpu_ptr(mod->percpu, cpu), from, size); +} + +bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) +{ + struct module *mod; + unsigned int cpu; + + preempt_disable(); + + list_for_each_entry_rcu(mod, &modules, list) { + if (mod->state == MODULE_STATE_UNFORMED) + continue; + if (!mod->percpu_size) + continue; + for_each_possible_cpu(cpu) { + void *start = per_cpu_ptr(mod->percpu, cpu); + void *va = (void *)addr; + + if (va >= start && va < start + mod->percpu_size) { + if (can_addr) { + *can_addr = (unsigned long) (va - start); + *can_addr += (unsigned long) + per_cpu_ptr(mod->percpu, + get_boot_cpu_id()); + } + preempt_enable(); + return true; + } + } + } + + preempt_enable(); + return false; +} + +/** + * is_module_percpu_address() - test whether address is from module static percpu + * @addr: address to test + * + * Test whether @addr belongs to module static percpu area. + * + * Return: %true if @addr is from module static percpu area + */ +bool is_module_percpu_address(unsigned long addr) +{ + return __is_module_percpu_address(addr, NULL); +} + +#else /* ... !CONFIG_SMP */ + +static inline void __percpu *mod_percpu(struct module *mod) +{ + return NULL; +} +static int percpu_modalloc(struct module *mod, struct load_info *info) +{ + /* UP modules shouldn't have this section: ENOMEM isn't quite right */ + if (info->sechdrs[info->index.pcpu].sh_size != 0) + return -ENOMEM; + return 0; +} +static inline void percpu_modfree(struct module *mod) +{ +} +static unsigned int find_pcpusec(struct load_info *info) +{ + return 0; +} +static inline void percpu_modcopy(struct module *mod, + const void *from, unsigned long size) +{ + /* pcpusec should be 0, and size of that section should be 0. */ + BUG_ON(size != 0); +} +bool is_module_percpu_address(unsigned long addr) +{ + return false; +} + +bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) +{ + return false; +} + +#endif /* CONFIG_SMP */ + +#define MODINFO_ATTR(field) \ +static void setup_modinfo_##field(struct module *mod, const char *s) \ +{ \ + mod->field = kstrdup(s, GFP_KERNEL); \ +} \ +static ssize_t show_modinfo_##field(struct module_attribute *mattr, \ + struct module_kobject *mk, char *buffer) \ +{ \ + return scnprintf(buffer, PAGE_SIZE, "%s\n", mk->mod->field); \ +} \ +static int modinfo_##field##_exists(struct module *mod) \ +{ \ + return mod->field != NULL; \ +} \ +static void free_modinfo_##field(struct module *mod) \ +{ \ + kfree(mod->field); \ + mod->field = NULL; \ +} \ +static struct module_attribute modinfo_##field = { \ + .attr = { .name = __stringify(field), .mode = 0444 }, \ + .show = show_modinfo_##field, \ + .setup = setup_modinfo_##field, \ + .test = modinfo_##field##_exists, \ + .free = free_modinfo_##field, \ +}; + +MODINFO_ATTR(version); +MODINFO_ATTR(srcversion); + +static char last_unloaded_module[MODULE_NAME_LEN+1]; + +#ifdef CONFIG_MODULE_UNLOAD + +EXPORT_TRACEPOINT_SYMBOL(module_get); + +/* MODULE_REF_BASE is the base reference count by kmodule loader. */ +#define MODULE_REF_BASE 1 + +/* Init the unload section of the module. */ +static int module_unload_init(struct module *mod) +{ + /* + * Initialize reference counter to MODULE_REF_BASE. + * refcnt == 0 means module is going. + */ + atomic_set(&mod->refcnt, MODULE_REF_BASE); + + INIT_LIST_HEAD(&mod->source_list); + INIT_LIST_HEAD(&mod->target_list); + + /* Hold reference count during initialization. */ + atomic_inc(&mod->refcnt); + + return 0; +} + +/* Does a already use b? */ +static int already_uses(struct module *a, struct module *b) +{ + struct module_use *use; + + list_for_each_entry(use, &b->source_list, source_list) { + if (use->source == a) { + pr_debug("%s uses %s!\n", a->name, b->name); + return 1; + } + } + pr_debug("%s does not use %s!\n", a->name, b->name); + return 0; +} + +/* + * Module a uses b + * - we add 'a' as a "source", 'b' as a "target" of module use + * - the module_use is added to the list of 'b' sources (so + * 'b' can walk the list to see who sourced them), and of 'a' + * targets (so 'a' can see what modules it targets). + */ +static int add_module_usage(struct module *a, struct module *b) +{ + struct module_use *use; + + pr_debug("Allocating new usage for %s.\n", a->name); + use = kmalloc(sizeof(*use), GFP_ATOMIC); + if (!use) + return -ENOMEM; + + use->source = a; + use->target = b; + list_add(&use->source_list, &b->source_list); + list_add(&use->target_list, &a->target_list); + return 0; +} + +/* Module a uses b: caller needs module_mutex() */ +static int ref_module(struct module *a, struct module *b) +{ + int err; + + if (b == NULL || already_uses(a, b)) + return 0; + + /* If module isn't available, we fail. */ + err = strong_try_module_get(b); + if (err) + return err; + + err = add_module_usage(a, b); + if (err) { + module_put(b); + return err; + } + return 0; +} + +/* Clear the unload stuff of the module. */ +static void module_unload_free(struct module *mod) +{ + struct module_use *use, *tmp; + + mutex_lock(&module_mutex); + list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) { + struct module *i = use->target; + pr_debug("%s unusing %s\n", mod->name, i->name); + module_put(i); + list_del(&use->source_list); + list_del(&use->target_list); + kfree(use); + } + mutex_unlock(&module_mutex); +} + +#ifdef CONFIG_MODULE_FORCE_UNLOAD +static inline int try_force_unload(unsigned int flags) +{ + int ret = (flags & O_TRUNC); + if (ret) + add_taint(TAINT_FORCED_RMMOD, LOCKDEP_NOW_UNRELIABLE); + return ret; +} +#else +static inline int try_force_unload(unsigned int flags) +{ + return 0; +} +#endif /* CONFIG_MODULE_FORCE_UNLOAD */ + +/* Try to release refcount of module, 0 means success. */ +static int try_release_module_ref(struct module *mod) +{ + int ret; + + /* Try to decrement refcnt which we set at loading */ + ret = atomic_sub_return(MODULE_REF_BASE, &mod->refcnt); + BUG_ON(ret < 0); + if (ret) + /* Someone can put this right now, recover with checking */ + ret = atomic_add_unless(&mod->refcnt, MODULE_REF_BASE, 0); + + return ret; +} + +static int try_stop_module(struct module *mod, int flags, int *forced) +{ + /* If it's not unused, quit unless we're forcing. */ + if (try_release_module_ref(mod) != 0) { + *forced = try_force_unload(flags); + if (!(*forced)) + return -EWOULDBLOCK; + } + + /* Mark it as dying. */ + mod->state = MODULE_STATE_GOING; + + return 0; +} + +/** + * module_refcount() - return the refcount or -1 if unloading + * @mod: the module we're checking + * + * Return: + * -1 if the module is in the process of unloading + * otherwise the number of references in the kernel to the module + */ +int module_refcount(struct module *mod) +{ + return atomic_read(&mod->refcnt) - MODULE_REF_BASE; +} +EXPORT_SYMBOL(module_refcount); + +/* This exists whether we can unload or not */ +static void free_module(struct module *mod); + +SYSCALL_DEFINE2(delete_module, const char __user *, name_user, + unsigned int, flags) +{ + struct module *mod; + char name[MODULE_NAME_LEN]; + int ret, forced = 0; + + if (!capable(CAP_SYS_MODULE) || modules_disabled) + return -EPERM; + + if (strncpy_from_user(name, name_user, MODULE_NAME_LEN-1) < 0) + return -EFAULT; + name[MODULE_NAME_LEN-1] = '\0'; + + audit_log_kern_module(name); + + if (mutex_lock_interruptible(&module_mutex) != 0) + return -EINTR; + + mod = find_module(name); + if (!mod) { + ret = -ENOENT; + goto out; + } + + if (!list_empty(&mod->source_list)) { + /* Other modules depend on us: get rid of them first. */ + ret = -EWOULDBLOCK; + goto out; + } + + /* Doing init or already dying? */ + if (mod->state != MODULE_STATE_LIVE) { + /* FIXME: if (force), slam module count damn the torpedoes */ + pr_debug("%s already dying\n", mod->name); + ret = -EBUSY; + goto out; + } + + /* If it has an init func, it must have an exit func to unload */ + if (mod->init && !mod->exit) { + forced = try_force_unload(flags); + if (!forced) { + /* This module can't be removed */ + ret = -EBUSY; + goto out; + } + } + + ret = try_stop_module(mod, flags, &forced); + if (ret != 0) + goto out; + + mutex_unlock(&module_mutex); + /* Final destruction now no one is using it. */ + if (mod->exit != NULL) + mod->exit(); + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_GOING, mod); + klp_module_going(mod); + ftrace_release_mod(mod); + + async_synchronize_full(); + + /* Store the name of the last unloaded module for diagnostic purposes */ + strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module)); + + free_module(mod); + /* someone could wait for the module in add_unformed_module() */ + wake_up_all(&module_wq); + return 0; +out: + mutex_unlock(&module_mutex); + return ret; +} + +static inline void print_unload_info(struct seq_file *m, struct module *mod) +{ + struct module_use *use; + int printed_something = 0; + + seq_printf(m, " %i ", module_refcount(mod)); + + /* + * Always include a trailing , so userspace can differentiate + * between this and the old multi-field proc format. + */ + list_for_each_entry(use, &mod->source_list, source_list) { + printed_something = 1; + seq_printf(m, "%s,", use->source->name); + } + + if (mod->init != NULL && mod->exit == NULL) { + printed_something = 1; + seq_puts(m, "[permanent],"); + } + + if (!printed_something) + seq_puts(m, "-"); +} + +void __symbol_put(const char *symbol) +{ + struct find_symbol_arg fsa = { + .name = symbol, + .gplok = true, + }; + + preempt_disable(); + BUG_ON(!find_symbol(&fsa)); + module_put(fsa.owner); + preempt_enable(); +} +EXPORT_SYMBOL(__symbol_put); + +/* Note this assumes addr is a function, which it currently always is. */ +void symbol_put_addr(void *addr) +{ + struct module *modaddr; + unsigned long a = (unsigned long)dereference_function_descriptor(addr); + + if (core_kernel_text(a)) + return; + + /* + * Even though we hold a reference on the module; we still need to + * disable preemption in order to safely traverse the data structure. + */ + preempt_disable(); + modaddr = __module_text_address(a); + BUG_ON(!modaddr); + module_put(modaddr); + preempt_enable(); +} +EXPORT_SYMBOL_GPL(symbol_put_addr); + +static ssize_t show_refcnt(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + return sprintf(buffer, "%i\n", module_refcount(mk->mod)); +} + +static struct module_attribute modinfo_refcnt = + __ATTR(refcnt, 0444, show_refcnt, NULL); + +void __module_get(struct module *module) +{ + if (module) { + preempt_disable(); + atomic_inc(&module->refcnt); + trace_module_get(module, _RET_IP_); + preempt_enable(); + } +} +EXPORT_SYMBOL(__module_get); + +bool try_module_get(struct module *module) +{ + bool ret = true; + + if (module) { + preempt_disable(); + /* Note: here, we can fail to get a reference */ + if (likely(module_is_live(module) && + atomic_inc_not_zero(&module->refcnt) != 0)) + trace_module_get(module, _RET_IP_); + else + ret = false; + + preempt_enable(); + } + return ret; +} +EXPORT_SYMBOL(try_module_get); + +void module_put(struct module *module) +{ + int ret; + + if (module) { + preempt_disable(); + ret = atomic_dec_if_positive(&module->refcnt); + WARN_ON(ret < 0); /* Failed to put refcount */ + trace_module_put(module, _RET_IP_); + preempt_enable(); + } +} +EXPORT_SYMBOL(module_put); + +#else /* !CONFIG_MODULE_UNLOAD */ +static inline void print_unload_info(struct seq_file *m, struct module *mod) +{ + /* We don't know the usage count, or what modules are using. */ + seq_puts(m, " - -"); +} + +static inline void module_unload_free(struct module *mod) +{ +} + +static int ref_module(struct module *a, struct module *b) +{ + return strong_try_module_get(b); +} + +static inline int module_unload_init(struct module *mod) +{ + return 0; +} +#endif /* CONFIG_MODULE_UNLOAD */ + +static size_t module_flags_taint(struct module *mod, char *buf) +{ + size_t l = 0; + int i; + + for (i = 0; i < TAINT_FLAGS_COUNT; i++) { + if (taint_flags[i].module && test_bit(i, &mod->taints)) + buf[l++] = taint_flags[i].c_true; + } + + return l; +} + +static ssize_t show_initstate(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + const char *state = "unknown"; + + switch (mk->mod->state) { + case MODULE_STATE_LIVE: + state = "live"; + break; + case MODULE_STATE_COMING: + state = "coming"; + break; + case MODULE_STATE_GOING: + state = "going"; + break; + default: + BUG(); + } + return sprintf(buffer, "%s\n", state); +} + +static struct module_attribute modinfo_initstate = + __ATTR(initstate, 0444, show_initstate, NULL); + +static ssize_t store_uevent(struct module_attribute *mattr, + struct module_kobject *mk, + const char *buffer, size_t count) +{ + int rc; + + rc = kobject_synth_uevent(&mk->kobj, buffer, count); + return rc ? rc : count; +} + +struct module_attribute module_uevent = + __ATTR(uevent, 0200, NULL, store_uevent); + +static ssize_t show_coresize(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + return sprintf(buffer, "%u\n", mk->mod->core_layout.size); +} + +static struct module_attribute modinfo_coresize = + __ATTR(coresize, 0444, show_coresize, NULL); + +static ssize_t show_initsize(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + return sprintf(buffer, "%u\n", mk->mod->init_layout.size); +} + +static struct module_attribute modinfo_initsize = + __ATTR(initsize, 0444, show_initsize, NULL); + +static ssize_t show_taint(struct module_attribute *mattr, + struct module_kobject *mk, char *buffer) +{ + size_t l; + + l = module_flags_taint(mk->mod, buffer); + buffer[l++] = '\n'; + return l; +} + +static struct module_attribute modinfo_taint = + __ATTR(taint, 0444, show_taint, NULL); + +static struct module_attribute *modinfo_attrs[] = { + &module_uevent, + &modinfo_version, + &modinfo_srcversion, + &modinfo_initstate, + &modinfo_coresize, + &modinfo_initsize, + &modinfo_taint, +#ifdef CONFIG_MODULE_UNLOAD + &modinfo_refcnt, +#endif + NULL, +}; + +static const char vermagic[] = VERMAGIC_STRING; + +static int try_to_force_load(struct module *mod, const char *reason) +{ +#ifdef CONFIG_MODULE_FORCE_LOAD + if (!test_taint(TAINT_FORCED_MODULE)) + pr_warn("%s: %s: kernel tainted.\n", mod->name, reason); + add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE); + return 0; +#else + return -ENOEXEC; +#endif +} + +#ifdef CONFIG_MODVERSIONS + +static u32 resolve_rel_crc(const s32 *crc) +{ + return *(u32 *)((void *)crc + *crc); +} + +static int check_version(const struct load_info *info, + const char *symname, + struct module *mod, + const s32 *crc) +{ + Elf_Shdr *sechdrs = info->sechdrs; + unsigned int versindex = info->index.vers; + unsigned int i, num_versions; + struct modversion_info *versions; + + /* Exporting module didn't supply crcs? OK, we're already tainted. */ + if (!crc) + return 1; + + /* No versions at all? modprobe --force does this. */ + if (versindex == 0) + return try_to_force_load(mod, symname) == 0; + + versions = (void *) sechdrs[versindex].sh_addr; + num_versions = sechdrs[versindex].sh_size + / sizeof(struct modversion_info); + + for (i = 0; i < num_versions; i++) { + u32 crcval; + + if (strcmp(versions[i].name, symname) != 0) + continue; + + if (IS_ENABLED(CONFIG_MODULE_REL_CRCS)) + crcval = resolve_rel_crc(crc); + else + crcval = *crc; + if (versions[i].crc == crcval) + return 1; + pr_debug("Found checksum %X vs module %lX\n", + crcval, versions[i].crc); + goto bad_version; + } + + /* Broken toolchain. Warn once, then let it go.. */ + pr_warn_once("%s: no symbol version for %s\n", info->name, symname); + return 1; + +bad_version: + pr_warn("%s: disagrees about version of symbol %s\n", + info->name, symname); + return 0; +} + +static inline int check_modstruct_version(const struct load_info *info, + struct module *mod) +{ + struct find_symbol_arg fsa = { + .name = "module_layout", + .gplok = true, + }; + + /* + * Since this should be found in kernel (which can't be removed), no + * locking is necessary -- use preempt_disable() to placate lockdep. + */ + preempt_disable(); + if (!find_symbol(&fsa)) { + preempt_enable(); + BUG(); + } + preempt_enable(); + return check_version(info, "module_layout", mod, fsa.crc); +} + +/* First part is kernel version, which we ignore if module has crcs. */ +static inline int same_magic(const char *amagic, const char *bmagic, + bool has_crcs) +{ + if (has_crcs) { + amagic += strcspn(amagic, " "); + bmagic += strcspn(bmagic, " "); + } + return strcmp(amagic, bmagic) == 0; +} +#else +static inline int check_version(const struct load_info *info, + const char *symname, + struct module *mod, + const s32 *crc) +{ + return 1; +} + +static inline int check_modstruct_version(const struct load_info *info, + struct module *mod) +{ + return 1; +} + +static inline int same_magic(const char *amagic, const char *bmagic, + bool has_crcs) +{ + return strcmp(amagic, bmagic) == 0; +} +#endif /* CONFIG_MODVERSIONS */ + +static char *get_modinfo(const struct load_info *info, const char *tag); +static char *get_next_modinfo(const struct load_info *info, const char *tag, + char *prev); + +static int verify_namespace_is_imported(const struct load_info *info, + const struct kernel_symbol *sym, + struct module *mod) +{ + const char *namespace; + char *imported_namespace; + + namespace = kernel_symbol_namespace(sym); + if (namespace && namespace[0]) { + imported_namespace = get_modinfo(info, "import_ns"); + while (imported_namespace) { + if (strcmp(namespace, imported_namespace) == 0) + return 0; + imported_namespace = get_next_modinfo( + info, "import_ns", imported_namespace); + } +#ifdef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS + pr_warn( +#else + pr_err( +#endif + "%s: module uses symbol (%s) from namespace %s, but does not import it.\n", + mod->name, kernel_symbol_name(sym), namespace); +#ifndef CONFIG_MODULE_ALLOW_MISSING_NAMESPACE_IMPORTS + return -EINVAL; +#endif + } + return 0; +} + +static bool inherit_taint(struct module *mod, struct module *owner) +{ + if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) + return true; + + if (mod->using_gplonly_symbols) { + pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n", + mod->name, owner->name); + return false; + } + + if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { + pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n", + mod->name, owner->name); + set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); + } + return true; +} + +/* Resolve a symbol for this module. I.e. if we find one, record usage. */ +static const struct kernel_symbol *resolve_symbol(struct module *mod, + const struct load_info *info, + const char *name, + char ownername[]) +{ + struct find_symbol_arg fsa = { + .name = name, + .gplok = !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), + .warn = true, + }; + int err; + + /* + * The module_mutex should not be a heavily contended lock; + * if we get the occasional sleep here, we'll go an extra iteration + * in the wait_event_interruptible(), which is harmless. + */ + sched_annotate_sleep(); + mutex_lock(&module_mutex); + if (!find_symbol(&fsa)) + goto unlock; + + if (fsa.license == GPL_ONLY) + mod->using_gplonly_symbols = true; + + if (!inherit_taint(mod, fsa.owner)) { + fsa.sym = NULL; + goto getname; + } + + if (!check_version(info, name, mod, fsa.crc)) { + fsa.sym = ERR_PTR(-EINVAL); + goto getname; + } + + err = verify_namespace_is_imported(info, fsa.sym, mod); + if (err) { + fsa.sym = ERR_PTR(err); + goto getname; + } + + err = ref_module(mod, fsa.owner); + if (err) { + fsa.sym = ERR_PTR(err); + goto getname; + } + +getname: + /* We must make copy under the lock if we failed to get ref. */ + strncpy(ownername, module_name(fsa.owner), MODULE_NAME_LEN); +unlock: + mutex_unlock(&module_mutex); + return fsa.sym; +} + +static const struct kernel_symbol * +resolve_symbol_wait(struct module *mod, + const struct load_info *info, + const char *name) +{ + const struct kernel_symbol *ksym; + char owner[MODULE_NAME_LEN]; + + if (wait_event_interruptible_timeout(module_wq, + !IS_ERR(ksym = resolve_symbol(mod, info, name, owner)) + || PTR_ERR(ksym) != -EBUSY, + 30 * HZ) <= 0) { + pr_warn("%s: gave up waiting for init of module %s.\n", + mod->name, owner); + } + return ksym; +} + +#ifdef CONFIG_KALLSYMS +static inline bool sect_empty(const Elf_Shdr *sect) +{ + return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0; +} +#endif + +/* + * /sys/module/foo/sections stuff + * J. Corbet + */ +#ifdef CONFIG_SYSFS + +#ifdef CONFIG_KALLSYMS +struct module_sect_attr { + struct bin_attribute battr; + unsigned long address; +}; + +struct module_sect_attrs { + struct attribute_group grp; + unsigned int nsections; + struct module_sect_attr attrs[]; +}; + +#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4)) +static ssize_t module_sect_read(struct file *file, struct kobject *kobj, + struct bin_attribute *battr, + char *buf, loff_t pos, size_t count) +{ + struct module_sect_attr *sattr = + container_of(battr, struct module_sect_attr, battr); + char bounce[MODULE_SECT_READ_SIZE + 1]; + size_t wrote; + + if (pos != 0) + return -EINVAL; + + /* + * Since we're a binary read handler, we must account for the + * trailing NUL byte that sprintf will write: if "buf" is + * too small to hold the NUL, or the NUL is exactly the last + * byte, the read will look like it got truncated by one byte. + * Since there is no way to ask sprintf nicely to not write + * the NUL, we have to use a bounce buffer. + */ + wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n", + kallsyms_show_value(file->f_cred) + ? (void *)sattr->address : NULL); + count = min(count, wrote); + memcpy(buf, bounce, count); + + return count; +} + +static void free_sect_attrs(struct module_sect_attrs *sect_attrs) +{ + unsigned int section; + + for (section = 0; section < sect_attrs->nsections; section++) + kfree(sect_attrs->attrs[section].battr.attr.name); + kfree(sect_attrs); +} + +static void add_sect_attrs(struct module *mod, const struct load_info *info) +{ + unsigned int nloaded = 0, i, size[2]; + struct module_sect_attrs *sect_attrs; + struct module_sect_attr *sattr; + struct bin_attribute **gattr; + + /* Count loaded sections and allocate structures */ + for (i = 0; i < info->hdr->e_shnum; i++) + if (!sect_empty(&info->sechdrs[i])) + nloaded++; + size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded), + sizeof(sect_attrs->grp.bin_attrs[0])); + size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]); + sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL); + if (sect_attrs == NULL) + return; + + /* Setup section attributes. */ + sect_attrs->grp.name = "sections"; + sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0]; + + sect_attrs->nsections = 0; + sattr = §_attrs->attrs[0]; + gattr = §_attrs->grp.bin_attrs[0]; + for (i = 0; i < info->hdr->e_shnum; i++) { + Elf_Shdr *sec = &info->sechdrs[i]; + if (sect_empty(sec)) + continue; + sysfs_bin_attr_init(&sattr->battr); + sattr->address = sec->sh_addr; + sattr->battr.attr.name = + kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL); + if (sattr->battr.attr.name == NULL) + goto out; + sect_attrs->nsections++; + sattr->battr.read = module_sect_read; + sattr->battr.size = MODULE_SECT_READ_SIZE; + sattr->battr.attr.mode = 0400; + *(gattr++) = &(sattr++)->battr; + } + *gattr = NULL; + + if (sysfs_create_group(&mod->mkobj.kobj, §_attrs->grp)) + goto out; + + mod->sect_attrs = sect_attrs; + return; + out: + free_sect_attrs(sect_attrs); +} + +static void remove_sect_attrs(struct module *mod) +{ + if (mod->sect_attrs) { + sysfs_remove_group(&mod->mkobj.kobj, + &mod->sect_attrs->grp); + /* + * We are positive that no one is using any sect attrs + * at this point. Deallocate immediately. + */ + free_sect_attrs(mod->sect_attrs); + mod->sect_attrs = NULL; + } +} + +/* + * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections. + */ + +struct module_notes_attrs { + struct kobject *dir; + unsigned int notes; + struct bin_attribute attrs[]; +}; + +static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, + char *buf, loff_t pos, size_t count) +{ + /* + * The caller checked the pos and count against our size. + */ + memcpy(buf, bin_attr->private + pos, count); + return count; +} + +static void free_notes_attrs(struct module_notes_attrs *notes_attrs, + unsigned int i) +{ + if (notes_attrs->dir) { + while (i-- > 0) + sysfs_remove_bin_file(notes_attrs->dir, + ¬es_attrs->attrs[i]); + kobject_put(notes_attrs->dir); + } + kfree(notes_attrs); +} + +static void add_notes_attrs(struct module *mod, const struct load_info *info) +{ + unsigned int notes, loaded, i; + struct module_notes_attrs *notes_attrs; + struct bin_attribute *nattr; + + /* failed to create section attributes, so can't create notes */ + if (!mod->sect_attrs) + return; + + /* Count notes sections and allocate structures. */ + notes = 0; + for (i = 0; i < info->hdr->e_shnum; i++) + if (!sect_empty(&info->sechdrs[i]) && + (info->sechdrs[i].sh_type == SHT_NOTE)) + ++notes; + + if (notes == 0) + return; + + notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes), + GFP_KERNEL); + if (notes_attrs == NULL) + return; + + notes_attrs->notes = notes; + nattr = ¬es_attrs->attrs[0]; + for (loaded = i = 0; i < info->hdr->e_shnum; ++i) { + if (sect_empty(&info->sechdrs[i])) + continue; + if (info->sechdrs[i].sh_type == SHT_NOTE) { + sysfs_bin_attr_init(nattr); + nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name; + nattr->attr.mode = S_IRUGO; + nattr->size = info->sechdrs[i].sh_size; + nattr->private = (void *) info->sechdrs[i].sh_addr; + nattr->read = module_notes_read; + ++nattr; + } + ++loaded; + } + + notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj); + if (!notes_attrs->dir) + goto out; + + for (i = 0; i < notes; ++i) + if (sysfs_create_bin_file(notes_attrs->dir, + ¬es_attrs->attrs[i])) + goto out; + + mod->notes_attrs = notes_attrs; + return; + + out: + free_notes_attrs(notes_attrs, i); +} + +static void remove_notes_attrs(struct module *mod) +{ + if (mod->notes_attrs) + free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes); +} + +#else + +static inline void add_sect_attrs(struct module *mod, + const struct load_info *info) +{ +} + +static inline void remove_sect_attrs(struct module *mod) +{ +} + +static inline void add_notes_attrs(struct module *mod, + const struct load_info *info) +{ +} + +static inline void remove_notes_attrs(struct module *mod) +{ +} +#endif /* CONFIG_KALLSYMS */ + +static void del_usage_links(struct module *mod) +{ +#ifdef CONFIG_MODULE_UNLOAD + struct module_use *use; + + mutex_lock(&module_mutex); + list_for_each_entry(use, &mod->target_list, target_list) + sysfs_remove_link(use->target->holders_dir, mod->name); + mutex_unlock(&module_mutex); +#endif +} + +static int add_usage_links(struct module *mod) +{ + int ret = 0; +#ifdef CONFIG_MODULE_UNLOAD + struct module_use *use; + + mutex_lock(&module_mutex); + list_for_each_entry(use, &mod->target_list, target_list) { + ret = sysfs_create_link(use->target->holders_dir, + &mod->mkobj.kobj, mod->name); + if (ret) + break; + } + mutex_unlock(&module_mutex); + if (ret) + del_usage_links(mod); +#endif + return ret; +} + +static void module_remove_modinfo_attrs(struct module *mod, int end); + +static int module_add_modinfo_attrs(struct module *mod) +{ + struct module_attribute *attr; + struct module_attribute *temp_attr; + int error = 0; + int i; + + mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) * + (ARRAY_SIZE(modinfo_attrs) + 1)), + GFP_KERNEL); + if (!mod->modinfo_attrs) + return -ENOMEM; + + temp_attr = mod->modinfo_attrs; + for (i = 0; (attr = modinfo_attrs[i]); i++) { + if (!attr->test || attr->test(mod)) { + memcpy(temp_attr, attr, sizeof(*temp_attr)); + sysfs_attr_init(&temp_attr->attr); + error = sysfs_create_file(&mod->mkobj.kobj, + &temp_attr->attr); + if (error) + goto error_out; + ++temp_attr; + } + } + + return 0; + +error_out: + if (i > 0) + module_remove_modinfo_attrs(mod, --i); + else + kfree(mod->modinfo_attrs); + return error; +} + +static void module_remove_modinfo_attrs(struct module *mod, int end) +{ + struct module_attribute *attr; + int i; + + for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) { + if (end >= 0 && i > end) + break; + /* pick a field to test for end of list */ + if (!attr->attr.name) + break; + sysfs_remove_file(&mod->mkobj.kobj, &attr->attr); + if (attr->free) + attr->free(mod); + } + kfree(mod->modinfo_attrs); +} + +static void mod_kobject_put(struct module *mod) +{ + DECLARE_COMPLETION_ONSTACK(c); + mod->mkobj.kobj_completion = &c; + kobject_put(&mod->mkobj.kobj); + wait_for_completion(&c); +} + +static int mod_sysfs_init(struct module *mod) +{ + int err; + struct kobject *kobj; + + if (!module_sysfs_initialized) { + pr_err("%s: module sysfs not initialized\n", mod->name); + err = -EINVAL; + goto out; + } + + kobj = kset_find_obj(module_kset, mod->name); + if (kobj) { + pr_err("%s: module is already loaded\n", mod->name); + kobject_put(kobj); + err = -EINVAL; + goto out; + } + + mod->mkobj.mod = mod; + + memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj)); + mod->mkobj.kobj.kset = module_kset; + err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL, + "%s", mod->name); + if (err) + mod_kobject_put(mod); + +out: + return err; +} + +static int mod_sysfs_setup(struct module *mod, + const struct load_info *info, + struct kernel_param *kparam, + unsigned int num_params) +{ + int err; + + err = mod_sysfs_init(mod); + if (err) + goto out; + + mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj); + if (!mod->holders_dir) { + err = -ENOMEM; + goto out_unreg; + } + + err = module_param_sysfs_setup(mod, kparam, num_params); + if (err) + goto out_unreg_holders; + + err = module_add_modinfo_attrs(mod); + if (err) + goto out_unreg_param; + + err = add_usage_links(mod); + if (err) + goto out_unreg_modinfo_attrs; + + add_sect_attrs(mod, info); + add_notes_attrs(mod, info); + + return 0; + +out_unreg_modinfo_attrs: + module_remove_modinfo_attrs(mod, -1); +out_unreg_param: + module_param_sysfs_remove(mod); +out_unreg_holders: + kobject_put(mod->holders_dir); +out_unreg: + mod_kobject_put(mod); +out: + return err; +} + +static void mod_sysfs_fini(struct module *mod) +{ + remove_notes_attrs(mod); + remove_sect_attrs(mod); + mod_kobject_put(mod); +} + +static void init_param_lock(struct module *mod) +{ + mutex_init(&mod->param_lock); +} +#else /* !CONFIG_SYSFS */ + +static int mod_sysfs_setup(struct module *mod, + const struct load_info *info, + struct kernel_param *kparam, + unsigned int num_params) +{ + return 0; +} + +static void mod_sysfs_fini(struct module *mod) +{ +} + +static void module_remove_modinfo_attrs(struct module *mod, int end) +{ +} + +static void del_usage_links(struct module *mod) +{ +} + +static void init_param_lock(struct module *mod) +{ +} +#endif /* CONFIG_SYSFS */ + +static void mod_sysfs_teardown(struct module *mod) +{ + del_usage_links(mod); + module_remove_modinfo_attrs(mod, -1); + module_param_sysfs_remove(mod); + kobject_put(mod->mkobj.drivers_dir); + kobject_put(mod->holders_dir); + mod_sysfs_fini(mod); +} + +/* + * LKM RO/NX protection: protect module's text/ro-data + * from modification and any data from execution. + * + * General layout of module is: + * [text] [read-only-data] [ro-after-init] [writable data] + * text_size -----^ ^ ^ ^ + * ro_size ------------------------| | | + * ro_after_init_size -----------------------------| | + * size -----------------------------------------------------------| + * + * These values are always page-aligned (as is base) + */ + +/* + * Since some arches are moving towards PAGE_KERNEL module allocations instead + * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() outside of the + * CONFIG_STRICT_MODULE_RWX block below because they are needed regardless of + * whether we are strict. + */ +#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX +static void frob_text(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base, + layout->text_size >> PAGE_SHIFT); +} + +static void module_enable_x(const struct module *mod) +{ + frob_text(&mod->core_layout, set_memory_x); + frob_text(&mod->init_layout, set_memory_x); +} +#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ +static void module_enable_x(const struct module *mod) { } +#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */ + +#ifdef CONFIG_STRICT_MODULE_RWX +static void frob_rodata(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->text_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->text_size, + (layout->ro_size - layout->text_size) >> PAGE_SHIFT); +} + +static void frob_ro_after_init(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->ro_size, + (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); +} + +static void frob_writable_data(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->ro_after_init_size, + (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); +} + +static void module_enable_ro(const struct module *mod, bool after_init) +{ + if (!rodata_enabled) + return; + + set_vm_flush_reset_perms(mod->core_layout.base); + set_vm_flush_reset_perms(mod->init_layout.base); + frob_text(&mod->core_layout, set_memory_ro); + + frob_rodata(&mod->core_layout, set_memory_ro); + frob_text(&mod->init_layout, set_memory_ro); + frob_rodata(&mod->init_layout, set_memory_ro); + + if (after_init) + frob_ro_after_init(&mod->core_layout, set_memory_ro); +} + +static void module_enable_nx(const struct module *mod) +{ + frob_rodata(&mod->core_layout, set_memory_nx); + frob_ro_after_init(&mod->core_layout, set_memory_nx); + frob_writable_data(&mod->core_layout, set_memory_nx); + frob_rodata(&mod->init_layout, set_memory_nx); + frob_writable_data(&mod->init_layout, set_memory_nx); +} + +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstrings, struct module *mod) +{ + const unsigned long shf_wx = SHF_WRITE|SHF_EXECINSTR; + int i; + + for (i = 0; i < hdr->e_shnum; i++) { + if ((sechdrs[i].sh_flags & shf_wx) == shf_wx) { + pr_err("%s: section %s (index %d) has invalid WRITE|EXEC flags\n", + mod->name, secstrings + sechdrs[i].sh_name, i); + return -ENOEXEC; + } + } + + return 0; +} + +#else /* !CONFIG_STRICT_MODULE_RWX */ +static void module_enable_nx(const struct module *mod) { } +static void module_enable_ro(const struct module *mod, bool after_init) {} +static int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, + char *secstrings, struct module *mod) +{ + return 0; +} +#endif /* CONFIG_STRICT_MODULE_RWX */ + +#ifdef CONFIG_LIVEPATCH +/* + * Persist Elf information about a module. Copy the Elf header, + * section header table, section string table, and symtab section + * index from info to mod->klp_info. + */ +static int copy_module_elf(struct module *mod, struct load_info *info) +{ + unsigned int size, symndx; + int ret; + + size = sizeof(*mod->klp_info); + mod->klp_info = kmalloc(size, GFP_KERNEL); + if (mod->klp_info == NULL) + return -ENOMEM; + + /* Elf header */ + size = sizeof(mod->klp_info->hdr); + memcpy(&mod->klp_info->hdr, info->hdr, size); + + /* Elf section header table */ + size = sizeof(*info->sechdrs) * info->hdr->e_shnum; + mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); + if (mod->klp_info->sechdrs == NULL) { + ret = -ENOMEM; + goto free_info; + } + + /* Elf section name string table */ + size = info->sechdrs[info->hdr->e_shstrndx].sh_size; + mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); + if (mod->klp_info->secstrings == NULL) { + ret = -ENOMEM; + goto free_sechdrs; + } + + /* Elf symbol section index */ + symndx = info->index.sym; + mod->klp_info->symndx = symndx; + + /* + * For livepatch modules, core_kallsyms.symtab is a complete + * copy of the original symbol table. Adjust sh_addr to point + * to core_kallsyms.symtab since the copy of the symtab in module + * init memory is freed at the end of do_init_module(). + */ + mod->klp_info->sechdrs[symndx].sh_addr = \ + (unsigned long) mod->core_kallsyms.symtab; + + return 0; + +free_sechdrs: + kfree(mod->klp_info->sechdrs); +free_info: + kfree(mod->klp_info); + return ret; +} + +static void free_module_elf(struct module *mod) +{ + kfree(mod->klp_info->sechdrs); + kfree(mod->klp_info->secstrings); + kfree(mod->klp_info); +} +#else /* !CONFIG_LIVEPATCH */ +static int copy_module_elf(struct module *mod, struct load_info *info) +{ + return 0; +} + +static void free_module_elf(struct module *mod) +{ +} +#endif /* CONFIG_LIVEPATCH */ + +void __weak module_memfree(void *module_region) +{ + /* + * This memory may be RO, and freeing RO memory in an interrupt is not + * supported by vmalloc. + */ + WARN_ON(in_interrupt()); + vfree(module_region); +} + +void __weak module_arch_cleanup(struct module *mod) +{ +} + +void __weak module_arch_freeing_init(struct module *mod) +{ +} + +static void cfi_cleanup(struct module *mod); + +/* Free a module, remove from lists, etc. */ +static void free_module(struct module *mod) +{ + trace_module_free(mod); + + mod_sysfs_teardown(mod); + + /* + * We leave it in list to prevent duplicate loads, but make sure + * that noone uses it while it's being deconstructed. + */ + mutex_lock(&module_mutex); + mod->state = MODULE_STATE_UNFORMED; + mutex_unlock(&module_mutex); + + /* Remove dynamic debug info */ + ddebug_remove_module(mod->name); + + /* Arch-specific cleanup. */ + module_arch_cleanup(mod); + + /* Module unload stuff */ + module_unload_free(mod); + + /* Free any allocated parameters. */ + destroy_params(mod->kp, mod->num_kp); + + if (is_livepatch_module(mod)) + free_module_elf(mod); + + /* Now we can delete it from the lists */ + mutex_lock(&module_mutex); + /* Unlink carefully: kallsyms could be walking list. */ + list_del_rcu(&mod->list); + mod_tree_remove(mod); + /* Remove this module from bug list, this uses list_del_rcu */ + module_bug_cleanup(mod); + /* Wait for RCU-sched synchronizing before releasing mod->list and buglist. */ + synchronize_rcu(); + mutex_unlock(&module_mutex); + + /* Clean up CFI for the module. */ + cfi_cleanup(mod); + + /* This may be empty, but that's OK */ + module_arch_freeing_init(mod); + module_memfree(mod->init_layout.base); + kfree(mod->args); + percpu_modfree(mod); + + /* Free lock-classes; relies on the preceding sync_rcu(). */ + lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); + + /* Finally, free the core (containing the module structure) */ + module_memfree(mod->core_layout.base); +} + +void *__symbol_get(const char *symbol) +{ + struct find_symbol_arg fsa = { + .name = symbol, + .gplok = true, + .warn = true, + }; + + preempt_disable(); + if (!find_symbol(&fsa) || strong_try_module_get(fsa.owner)) { + preempt_enable(); + return NULL; + } + preempt_enable(); + return (void *)kernel_symbol_value(fsa.sym); +} +EXPORT_SYMBOL_GPL(__symbol_get); + +/* + * Ensure that an exported symbol [global namespace] does not already exist + * in the kernel or in some other module's exported symbol table. + * + * You must hold the module_mutex. + */ +static int verify_exported_symbols(struct module *mod) +{ + unsigned int i; + const struct kernel_symbol *s; + struct { + const struct kernel_symbol *sym; + unsigned int num; + } arr[] = { + { mod->syms, mod->num_syms }, + { mod->gpl_syms, mod->num_gpl_syms }, + }; + + for (i = 0; i < ARRAY_SIZE(arr); i++) { + for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { + struct find_symbol_arg fsa = { + .name = kernel_symbol_name(s), + .gplok = true, + }; + if (find_symbol(&fsa)) { + pr_err("%s: exports duplicate symbol %s" + " (owned by %s)\n", + mod->name, kernel_symbol_name(s), + module_name(fsa.owner)); + return -ENOEXEC; + } + } + } + return 0; +} + +static bool ignore_undef_symbol(Elf_Half emachine, const char *name) +{ + /* + * On x86, PIC code and Clang non-PIC code may have call foo@PLT. GNU as + * before 2.37 produces an unreferenced _GLOBAL_OFFSET_TABLE_ on x86-64. + * i386 has a similar problem but may not deserve a fix. + * + * If we ever have to ignore many symbols, consider refactoring the code to + * only warn if referenced by a relocation. + */ + if (emachine == EM_386 || emachine == EM_X86_64) + return !strcmp(name, "_GLOBAL_OFFSET_TABLE_"); + return false; +} + +/* Change all symbols so that st_value encodes the pointer directly. */ +static int simplify_symbols(struct module *mod, const struct load_info *info) +{ + Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; + Elf_Sym *sym = (void *)symsec->sh_addr; + unsigned long secbase; + unsigned int i; + int ret = 0; + const struct kernel_symbol *ksym; + + for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { + const char *name = info->strtab + sym[i].st_name; + + switch (sym[i].st_shndx) { + case SHN_COMMON: + /* Ignore common symbols */ + if (!strncmp(name, "__gnu_lto", 9)) + break; + + /* + * We compiled with -fno-common. These are not + * supposed to happen. + */ + pr_debug("Common symbol: %s\n", name); + pr_warn("%s: please compile with -fno-common\n", + mod->name); + ret = -ENOEXEC; + break; + + case SHN_ABS: + /* Don't need to do anything */ + pr_debug("Absolute symbol: 0x%08lx\n", + (long)sym[i].st_value); + break; + + case SHN_LIVEPATCH: + /* Livepatch symbols are resolved by livepatch */ + break; + + case SHN_UNDEF: + ksym = resolve_symbol_wait(mod, info, name); + /* Ok if resolved. */ + if (ksym && !IS_ERR(ksym)) { + sym[i].st_value = kernel_symbol_value(ksym); + break; + } + + /* Ok if weak or ignored. */ + if (!ksym && + (ELF_ST_BIND(sym[i].st_info) == STB_WEAK || + ignore_undef_symbol(info->hdr->e_machine, name))) + break; + + ret = PTR_ERR(ksym) ?: -ENOENT; + pr_warn("%s: Unknown symbol %s (err %d)\n", + mod->name, name, ret); + break; + + default: + /* Divert to percpu allocation if a percpu var. */ + if (sym[i].st_shndx == info->index.pcpu) + secbase = (unsigned long)mod_percpu(mod); + else + secbase = info->sechdrs[sym[i].st_shndx].sh_addr; + sym[i].st_value += secbase; + break; + } + } + + return ret; +} + +static int apply_relocations(struct module *mod, const struct load_info *info) +{ + unsigned int i; + int err = 0; + + /* Now do relocations. */ + for (i = 1; i < info->hdr->e_shnum; i++) { + unsigned int infosec = info->sechdrs[i].sh_info; + + /* Not a valid relocation section? */ + if (infosec >= info->hdr->e_shnum) + continue; + + /* Don't bother with non-allocated sections */ + if (!(info->sechdrs[infosec].sh_flags & SHF_ALLOC)) + continue; + + if (info->sechdrs[i].sh_flags & SHF_RELA_LIVEPATCH) + err = klp_apply_section_relocs(mod, info->sechdrs, + info->secstrings, + info->strtab, + info->index.sym, i, + NULL); + else if (info->sechdrs[i].sh_type == SHT_REL) + err = apply_relocate(info->sechdrs, info->strtab, + info->index.sym, i, mod); + else if (info->sechdrs[i].sh_type == SHT_RELA) + err = apply_relocate_add(info->sechdrs, info->strtab, + info->index.sym, i, mod); + if (err < 0) + break; + } + return err; +} + +/* Additional bytes needed by arch in front of individual sections */ +unsigned int __weak arch_mod_section_prepend(struct module *mod, + unsigned int section) +{ + /* default implementation just returns zero */ + return 0; +} + +/* Update size with this section: return offset. */ +static long get_offset(struct module *mod, unsigned int *size, + Elf_Shdr *sechdr, unsigned int section) +{ + long ret; + + *size += arch_mod_section_prepend(mod, section); + ret = ALIGN(*size, sechdr->sh_addralign ?: 1); + *size = ret + sechdr->sh_size; + return ret; +} + +static bool module_init_layout_section(const char *sname) +{ +#ifndef CONFIG_MODULE_UNLOAD + if (module_exit_section(sname)) + return true; +#endif + return module_init_section(sname); +} + +/* + * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld + * might -- code, read-only data, read-write data, small data. Tally + * sizes, and place the offsets into sh_entsize fields: high bit means it + * belongs in init. + */ +static void layout_sections(struct module *mod, struct load_info *info) +{ + static unsigned long const masks[][2] = { + /* + * NOTE: all executable code must be the first section + * in this array; otherwise modify the text_size + * finder in the two loops below + */ + { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, + { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, + { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, + { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, + { ARCH_SHF_SMALL | SHF_ALLOC, 0 } + }; + unsigned int m, i; + + for (i = 0; i < info->hdr->e_shnum; i++) + info->sechdrs[i].sh_entsize = ~0UL; + + pr_debug("Core section allocation order:\n"); + for (m = 0; m < ARRAY_SIZE(masks); ++m) { + for (i = 0; i < info->hdr->e_shnum; ++i) { + Elf_Shdr *s = &info->sechdrs[i]; + const char *sname = info->secstrings + s->sh_name; + + if ((s->sh_flags & masks[m][0]) != masks[m][0] + || (s->sh_flags & masks[m][1]) + || s->sh_entsize != ~0UL + || module_init_layout_section(sname)) + continue; + s->sh_entsize = get_offset(mod, &mod->core_layout.size, s, i); + pr_debug("\t%s\n", sname); + } + switch (m) { + case 0: /* executable */ + mod->core_layout.size = debug_align(mod->core_layout.size); + mod->core_layout.text_size = mod->core_layout.size; + break; + case 1: /* RO: text and ro-data */ + mod->core_layout.size = debug_align(mod->core_layout.size); + mod->core_layout.ro_size = mod->core_layout.size; + break; + case 2: /* RO after init */ + mod->core_layout.size = debug_align(mod->core_layout.size); + mod->core_layout.ro_after_init_size = mod->core_layout.size; + break; + case 4: /* whole core */ + mod->core_layout.size = debug_align(mod->core_layout.size); + break; + } + } + + pr_debug("Init section allocation order:\n"); + for (m = 0; m < ARRAY_SIZE(masks); ++m) { + for (i = 0; i < info->hdr->e_shnum; ++i) { + Elf_Shdr *s = &info->sechdrs[i]; + const char *sname = info->secstrings + s->sh_name; + + if ((s->sh_flags & masks[m][0]) != masks[m][0] + || (s->sh_flags & masks[m][1]) + || s->sh_entsize != ~0UL + || !module_init_layout_section(sname)) + continue; + s->sh_entsize = (get_offset(mod, &mod->init_layout.size, s, i) + | INIT_OFFSET_MASK); + pr_debug("\t%s\n", sname); + } + switch (m) { + case 0: /* executable */ + mod->init_layout.size = debug_align(mod->init_layout.size); + mod->init_layout.text_size = mod->init_layout.size; + break; + case 1: /* RO: text and ro-data */ + mod->init_layout.size = debug_align(mod->init_layout.size); + mod->init_layout.ro_size = mod->init_layout.size; + break; + case 2: + /* + * RO after init doesn't apply to init_layout (only + * core_layout), so it just takes the value of ro_size. + */ + mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; + break; + case 4: /* whole init */ + mod->init_layout.size = debug_align(mod->init_layout.size); + break; + } + } +} + +static void set_license(struct module *mod, const char *license) +{ + if (!license) + license = "unspecified"; + + if (!license_is_gpl_compatible(license)) { + if (!test_taint(TAINT_PROPRIETARY_MODULE)) + pr_warn("%s: module license '%s' taints kernel.\n", + mod->name, license); + add_taint_module(mod, TAINT_PROPRIETARY_MODULE, + LOCKDEP_NOW_UNRELIABLE); + } +} + +/* Parse tag=value strings from .modinfo section */ +static char *next_string(char *string, unsigned long *secsize) +{ + /* Skip non-zero chars */ + while (string[0]) { + string++; + if ((*secsize)-- <= 1) + return NULL; + } + + /* Skip any zero padding. */ + while (!string[0]) { + string++; + if ((*secsize)-- <= 1) + return NULL; + } + return string; +} + +static char *get_next_modinfo(const struct load_info *info, const char *tag, + char *prev) +{ + char *p; + unsigned int taglen = strlen(tag); + Elf_Shdr *infosec = &info->sechdrs[info->index.info]; + unsigned long size = infosec->sh_size; + + /* + * get_modinfo() calls made before rewrite_section_headers() + * must use sh_offset, as sh_addr isn't set! + */ + char *modinfo = (char *)info->hdr + infosec->sh_offset; + + if (prev) { + size -= prev - modinfo; + modinfo = next_string(prev, &size); + } + + for (p = modinfo; p; p = next_string(p, &size)) { + if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') + return p + taglen + 1; + } + return NULL; +} + +static char *get_modinfo(const struct load_info *info, const char *tag) +{ + return get_next_modinfo(info, tag, NULL); +} + +static void setup_modinfo(struct module *mod, struct load_info *info) +{ + struct module_attribute *attr; + int i; + + for (i = 0; (attr = modinfo_attrs[i]); i++) { + if (attr->setup) + attr->setup(mod, get_modinfo(info, attr->attr.name)); + } +} + +static void free_modinfo(struct module *mod) +{ + struct module_attribute *attr; + int i; + + for (i = 0; (attr = modinfo_attrs[i]); i++) { + if (attr->free) + attr->free(mod); + } +} + +#ifdef CONFIG_KALLSYMS + +/* Lookup exported symbol in given range of kernel_symbols */ +static const struct kernel_symbol *lookup_exported_symbol(const char *name, + const struct kernel_symbol *start, + const struct kernel_symbol *stop) +{ + return bsearch(name, start, stop - start, + sizeof(struct kernel_symbol), cmp_name); +} + +static int is_exported(const char *name, unsigned long value, + const struct module *mod) +{ + const struct kernel_symbol *ks; + if (!mod) + ks = lookup_exported_symbol(name, __start___ksymtab, __stop___ksymtab); + else + ks = lookup_exported_symbol(name, mod->syms, mod->syms + mod->num_syms); + + return ks != NULL && kernel_symbol_value(ks) == value; +} + +/* As per nm */ +static char elf_type(const Elf_Sym *sym, const struct load_info *info) +{ + const Elf_Shdr *sechdrs = info->sechdrs; + + if (ELF_ST_BIND(sym->st_info) == STB_WEAK) { + if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT) + return 'v'; + else + return 'w'; + } + if (sym->st_shndx == SHN_UNDEF) + return 'U'; + if (sym->st_shndx == SHN_ABS || sym->st_shndx == info->index.pcpu) + return 'a'; + if (sym->st_shndx >= SHN_LORESERVE) + return '?'; + if (sechdrs[sym->st_shndx].sh_flags & SHF_EXECINSTR) + return 't'; + if (sechdrs[sym->st_shndx].sh_flags & SHF_ALLOC + && sechdrs[sym->st_shndx].sh_type != SHT_NOBITS) { + if (!(sechdrs[sym->st_shndx].sh_flags & SHF_WRITE)) + return 'r'; + else if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) + return 'g'; + else + return 'd'; + } + if (sechdrs[sym->st_shndx].sh_type == SHT_NOBITS) { + if (sechdrs[sym->st_shndx].sh_flags & ARCH_SHF_SMALL) + return 's'; + else + return 'b'; + } + if (strstarts(info->secstrings + sechdrs[sym->st_shndx].sh_name, + ".debug")) { + return 'n'; + } + return '?'; +} + +static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs, + unsigned int shnum, unsigned int pcpundx) +{ + const Elf_Shdr *sec; + + if (src->st_shndx == SHN_UNDEF + || src->st_shndx >= shnum + || !src->st_name) + return false; + +#ifdef CONFIG_KALLSYMS_ALL + if (src->st_shndx == pcpundx) + return true; +#endif + + sec = sechdrs + src->st_shndx; + if (!(sec->sh_flags & SHF_ALLOC) +#ifndef CONFIG_KALLSYMS_ALL + || !(sec->sh_flags & SHF_EXECINSTR) +#endif + || (sec->sh_entsize & INIT_OFFSET_MASK)) + return false; + + return true; +} + +/* + * We only allocate and copy the strings needed by the parts of symtab + * we keep. This is simple, but has the effect of making multiple + * copies of duplicates. We could be more sophisticated, see + * linux-kernel thread starting with + * <73defb5e4bca04a6431392cc341112b1@localhost>. + */ +static void layout_symtab(struct module *mod, struct load_info *info) +{ + Elf_Shdr *symsect = info->sechdrs + info->index.sym; + Elf_Shdr *strsect = info->sechdrs + info->index.str; + const Elf_Sym *src; + unsigned int i, nsrc, ndst, strtab_size = 0; + + /* Put symbol section at end of init part of module. */ + symsect->sh_flags |= SHF_ALLOC; + symsect->sh_entsize = get_offset(mod, &mod->init_layout.size, symsect, + info->index.sym) | INIT_OFFSET_MASK; + pr_debug("\t%s\n", info->secstrings + symsect->sh_name); + + src = (void *)info->hdr + symsect->sh_offset; + nsrc = symsect->sh_size / sizeof(*src); + + /* Compute total space required for the core symbols' strtab. */ + for (ndst = i = 0; i < nsrc; i++) { + if (i == 0 || is_livepatch_module(mod) || + is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, + info->index.pcpu)) { + strtab_size += strlen(&info->strtab[src[i].st_name])+1; + ndst++; + } + } + + /* Append room for core symbols at end of core part. */ + info->symoffs = ALIGN(mod->core_layout.size, symsect->sh_addralign ?: 1); + info->stroffs = mod->core_layout.size = info->symoffs + ndst * sizeof(Elf_Sym); + mod->core_layout.size += strtab_size; + info->core_typeoffs = mod->core_layout.size; + mod->core_layout.size += ndst * sizeof(char); + mod->core_layout.size = debug_align(mod->core_layout.size); + + /* Put string table section at end of init part of module. */ + strsect->sh_flags |= SHF_ALLOC; + strsect->sh_entsize = get_offset(mod, &mod->init_layout.size, strsect, + info->index.str) | INIT_OFFSET_MASK; + pr_debug("\t%s\n", info->secstrings + strsect->sh_name); + + /* We'll tack temporary mod_kallsyms on the end. */ + mod->init_layout.size = ALIGN(mod->init_layout.size, + __alignof__(struct mod_kallsyms)); + info->mod_kallsyms_init_off = mod->init_layout.size; + mod->init_layout.size += sizeof(struct mod_kallsyms); + info->init_typeoffs = mod->init_layout.size; + mod->init_layout.size += nsrc * sizeof(char); + mod->init_layout.size = debug_align(mod->init_layout.size); +} + +/* + * We use the full symtab and strtab which layout_symtab arranged to + * be appended to the init section. Later we switch to the cut-down + * core-only ones. + */ +static void add_kallsyms(struct module *mod, const struct load_info *info) +{ + unsigned int i, ndst; + const Elf_Sym *src; + Elf_Sym *dst; + char *s; + Elf_Shdr *symsec = &info->sechdrs[info->index.sym]; + + /* Set up to point into init section. */ + mod->kallsyms = mod->init_layout.base + info->mod_kallsyms_init_off; + + mod->kallsyms->symtab = (void *)symsec->sh_addr; + mod->kallsyms->num_symtab = symsec->sh_size / sizeof(Elf_Sym); + /* Make sure we get permanent strtab: don't use info->strtab. */ + mod->kallsyms->strtab = (void *)info->sechdrs[info->index.str].sh_addr; + mod->kallsyms->typetab = mod->init_layout.base + info->init_typeoffs; + + /* + * Now populate the cut down core kallsyms for after init + * and set types up while we still have access to sections. + */ + mod->core_kallsyms.symtab = dst = mod->core_layout.base + info->symoffs; + mod->core_kallsyms.strtab = s = mod->core_layout.base + info->stroffs; + mod->core_kallsyms.typetab = mod->core_layout.base + info->core_typeoffs; + src = mod->kallsyms->symtab; + for (ndst = i = 0; i < mod->kallsyms->num_symtab; i++) { + mod->kallsyms->typetab[i] = elf_type(src + i, info); + if (i == 0 || is_livepatch_module(mod) || + is_core_symbol(src+i, info->sechdrs, info->hdr->e_shnum, + info->index.pcpu)) { + mod->core_kallsyms.typetab[ndst] = + mod->kallsyms->typetab[i]; + dst[ndst] = src[i]; + dst[ndst++].st_name = s - mod->core_kallsyms.strtab; + s += strlcpy(s, &mod->kallsyms->strtab[src[i].st_name], + KSYM_NAME_LEN) + 1; + } + } + mod->core_kallsyms.num_symtab = ndst; +} +#else +static inline void layout_symtab(struct module *mod, struct load_info *info) +{ +} + +static void add_kallsyms(struct module *mod, const struct load_info *info) +{ +} +#endif /* CONFIG_KALLSYMS */ + +#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) +static void init_build_id(struct module *mod, const struct load_info *info) +{ + const Elf_Shdr *sechdr; + unsigned int i; + + for (i = 0; i < info->hdr->e_shnum; i++) { + sechdr = &info->sechdrs[i]; + if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE && + !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id, + sechdr->sh_size)) + break; + } +} +#else +static void init_build_id(struct module *mod, const struct load_info *info) +{ +} +#endif + +static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num) +{ + if (!debug) + return; + ddebug_add_module(debug, num, mod->name); +} + +static void dynamic_debug_remove(struct module *mod, struct _ddebug *debug) +{ + if (debug) + ddebug_remove_module(mod->name); +} + +void * __weak module_alloc(unsigned long size) +{ + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, + NUMA_NO_NODE, __builtin_return_address(0)); +} + +bool __weak module_init_section(const char *name) +{ + return strstarts(name, ".init"); +} + +bool __weak module_exit_section(const char *name) +{ + return strstarts(name, ".exit"); +} + +#ifdef CONFIG_DEBUG_KMEMLEAK +static void kmemleak_load_module(const struct module *mod, + const struct load_info *info) +{ + unsigned int i; + + /* only scan the sections containing data */ + kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); + + for (i = 1; i < info->hdr->e_shnum; i++) { + /* Scan all writable sections that's not executable */ + if (!(info->sechdrs[i].sh_flags & SHF_ALLOC) || + !(info->sechdrs[i].sh_flags & SHF_WRITE) || + (info->sechdrs[i].sh_flags & SHF_EXECINSTR)) + continue; + + kmemleak_scan_area((void *)info->sechdrs[i].sh_addr, + info->sechdrs[i].sh_size, GFP_KERNEL); + } +} +#else +static inline void kmemleak_load_module(const struct module *mod, + const struct load_info *info) +{ +} +#endif + +#ifdef CONFIG_MODULE_SIG +static int module_sig_check(struct load_info *info, int flags) +{ + int err = -ENODATA; + const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; + const char *reason; + const void *mod = info->hdr; + bool mangled_module = flags & (MODULE_INIT_IGNORE_MODVERSIONS | + MODULE_INIT_IGNORE_VERMAGIC); + /* + * Do not allow mangled modules as a module with version information + * removed is no longer the module that was signed. + */ + if (!mangled_module && + info->len > markerlen && + memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { + /* We truncate the module to discard the signature */ + info->len -= markerlen; + err = mod_verify_sig(mod, info); + if (!err) { + info->sig_ok = true; + return 0; + } + } + + /* + * We don't permit modules to be loaded into the trusted kernels + * without a valid signature on them, but if we're not enforcing, + * certain errors are non-fatal. + */ + switch (err) { + case -ENODATA: + reason = "unsigned module"; + break; + case -ENOPKG: + reason = "module with unsupported crypto"; + break; + case -ENOKEY: + reason = "module with unavailable key"; + break; + + default: + /* + * All other errors are fatal, including lack of memory, + * unparseable signatures, and signature check failures -- + * even if signatures aren't required. + */ + return err; + } + + if (is_module_sig_enforced()) { + pr_notice("Loading of %s is rejected\n", reason); + return -EKEYREJECTED; + } + + return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); +} +#else /* !CONFIG_MODULE_SIG */ +static int module_sig_check(struct load_info *info, int flags) +{ + return 0; +} +#endif /* !CONFIG_MODULE_SIG */ + +static int validate_section_offset(struct load_info *info, Elf_Shdr *shdr) +{ +#if defined(CONFIG_64BIT) + unsigned long long secend; +#else + unsigned long secend; +#endif + + /* + * Check for both overflow and offset/size being + * too large. + */ + secend = shdr->sh_offset + shdr->sh_size; + if (secend < shdr->sh_offset || secend > info->len) + return -ENOEXEC; + + return 0; +} + +/* + * Sanity checks against invalid binaries, wrong arch, weird elf version. + * + * Also do basic validity checks against section offsets and sizes, the + * section name string table, and the indices used for it (sh_name). + */ +static int elf_validity_check(struct load_info *info) +{ + unsigned int i; + Elf_Shdr *shdr, *strhdr; + int err; + + if (info->len < sizeof(*(info->hdr))) { + pr_err("Invalid ELF header len %lu\n", info->len); + goto no_exec; + } + + if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0) { + pr_err("Invalid ELF header magic: != %s\n", ELFMAG); + goto no_exec; + } + if (info->hdr->e_type != ET_REL) { + pr_err("Invalid ELF header type: %u != %u\n", + info->hdr->e_type, ET_REL); + goto no_exec; + } + if (!elf_check_arch(info->hdr)) { + pr_err("Invalid architecture in ELF header: %u\n", + info->hdr->e_machine); + goto no_exec; + } + if (info->hdr->e_shentsize != sizeof(Elf_Shdr)) { + pr_err("Invalid ELF section header size\n"); + goto no_exec; + } + + /* + * e_shnum is 16 bits, and sizeof(Elf_Shdr) is + * known and small. So e_shnum * sizeof(Elf_Shdr) + * will not overflow unsigned long on any platform. + */ + if (info->hdr->e_shoff >= info->len + || (info->hdr->e_shnum * sizeof(Elf_Shdr) > + info->len - info->hdr->e_shoff)) { + pr_err("Invalid ELF section header overflow\n"); + goto no_exec; + } + + info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; + + /* + * Verify if the section name table index is valid. + */ + if (info->hdr->e_shstrndx == SHN_UNDEF + || info->hdr->e_shstrndx >= info->hdr->e_shnum) { + pr_err("Invalid ELF section name index: %d || e_shstrndx (%d) >= e_shnum (%d)\n", + info->hdr->e_shstrndx, info->hdr->e_shstrndx, + info->hdr->e_shnum); + goto no_exec; + } + + strhdr = &info->sechdrs[info->hdr->e_shstrndx]; + err = validate_section_offset(info, strhdr); + if (err < 0) { + pr_err("Invalid ELF section hdr(type %u)\n", strhdr->sh_type); + return err; + } + + /* + * The section name table must be NUL-terminated, as required + * by the spec. This makes strcmp and pr_* calls that access + * strings in the section safe. + */ + info->secstrings = (void *)info->hdr + strhdr->sh_offset; + if (info->secstrings[strhdr->sh_size - 1] != '\0') { + pr_err("ELF Spec violation: section name table isn't null terminated\n"); + goto no_exec; + } + + /* + * The code assumes that section 0 has a length of zero and + * an addr of zero, so check for it. + */ + if (info->sechdrs[0].sh_type != SHT_NULL + || info->sechdrs[0].sh_size != 0 + || info->sechdrs[0].sh_addr != 0) { + pr_err("ELF Spec violation: section 0 type(%d)!=SH_NULL or non-zero len or addr\n", + info->sechdrs[0].sh_type); + goto no_exec; + } + + for (i = 1; i < info->hdr->e_shnum; i++) { + shdr = &info->sechdrs[i]; + switch (shdr->sh_type) { + case SHT_NULL: + case SHT_NOBITS: + continue; + case SHT_SYMTAB: + if (shdr->sh_link == SHN_UNDEF + || shdr->sh_link >= info->hdr->e_shnum) { + pr_err("Invalid ELF sh_link!=SHN_UNDEF(%d) or (sh_link(%d) >= hdr->e_shnum(%d)\n", + shdr->sh_link, shdr->sh_link, + info->hdr->e_shnum); + goto no_exec; + } + fallthrough; + default: + err = validate_section_offset(info, shdr); + if (err < 0) { + pr_err("Invalid ELF section in module (section %u type %u)\n", + i, shdr->sh_type); + return err; + } + + if (shdr->sh_flags & SHF_ALLOC) { + if (shdr->sh_name >= strhdr->sh_size) { + pr_err("Invalid ELF section name in module (section %u type %u)\n", + i, shdr->sh_type); + return -ENOEXEC; + } + } + break; + } + } + + return 0; + +no_exec: + return -ENOEXEC; +} + +#define COPY_CHUNK_SIZE (16*PAGE_SIZE) + +static int copy_chunked_from_user(void *dst, const void __user *usrc, unsigned long len) +{ + do { + unsigned long n = min(len, COPY_CHUNK_SIZE); + + if (copy_from_user(dst, usrc, n) != 0) + return -EFAULT; + cond_resched(); + dst += n; + usrc += n; + len -= n; + } while (len); + return 0; +} + +#ifdef CONFIG_LIVEPATCH +static int check_modinfo_livepatch(struct module *mod, struct load_info *info) +{ + if (get_modinfo(info, "livepatch")) { + mod->klp = true; + add_taint_module(mod, TAINT_LIVEPATCH, LOCKDEP_STILL_OK); + pr_notice_once("%s: tainting kernel with TAINT_LIVEPATCH\n", + mod->name); + } + + return 0; +} +#else /* !CONFIG_LIVEPATCH */ +static int check_modinfo_livepatch(struct module *mod, struct load_info *info) +{ + if (get_modinfo(info, "livepatch")) { + pr_err("%s: module is marked as livepatch module, but livepatch support is disabled", + mod->name); + return -ENOEXEC; + } + + return 0; +} +#endif /* CONFIG_LIVEPATCH */ + +static void check_modinfo_retpoline(struct module *mod, struct load_info *info) +{ + if (retpoline_module_ok(get_modinfo(info, "retpoline"))) + return; + + pr_warn("%s: loading module not compiled with retpoline compiler.\n", + mod->name); +} + +/* Sets info->hdr and info->len. */ +static int copy_module_from_user(const void __user *umod, unsigned long len, + struct load_info *info) +{ + int err; + + info->len = len; + if (info->len < sizeof(*(info->hdr))) + return -ENOEXEC; + + err = security_kernel_load_data(LOADING_MODULE, true); + if (err) + return err; + + /* Suck in entire file: we'll want most of it. */ + info->hdr = __vmalloc(info->len, GFP_KERNEL | __GFP_NOWARN); + if (!info->hdr) + return -ENOMEM; + + if (copy_chunked_from_user(info->hdr, umod, info->len) != 0) { + err = -EFAULT; + goto out; + } + + err = security_kernel_post_load_data((char *)info->hdr, info->len, + LOADING_MODULE, "init_module"); +out: + if (err) + vfree(info->hdr); + + return err; +} + +static void free_copy(struct load_info *info, int flags) +{ + if (flags & MODULE_INIT_COMPRESSED_FILE) + module_decompress_cleanup(info); + else + vfree(info->hdr); +} + +static int rewrite_section_headers(struct load_info *info, int flags) +{ + unsigned int i; + + /* This should always be true, but let's be sure. */ + info->sechdrs[0].sh_addr = 0; + + for (i = 1; i < info->hdr->e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + + /* + * Mark all sections sh_addr with their address in the + * temporary image. + */ + shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; + + } + + /* Track but don't keep modinfo and version sections. */ + info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; + info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; + + return 0; +} + +/* + * Set up our basic convenience variables (pointers to section headers, + * search for module section index etc), and do some basic section + * verification. + * + * Set info->mod to the temporary copy of the module in info->hdr. The final one + * will be allocated in move_module(). + */ +static int setup_load_info(struct load_info *info, int flags) +{ + unsigned int i; + + /* Try to find a name early so we can log errors with a module name */ + info->index.info = find_sec(info, ".modinfo"); + if (info->index.info) + info->name = get_modinfo(info, "name"); + + /* Find internal symbols and strings. */ + for (i = 1; i < info->hdr->e_shnum; i++) { + if (info->sechdrs[i].sh_type == SHT_SYMTAB) { + info->index.sym = i; + info->index.str = info->sechdrs[i].sh_link; + info->strtab = (char *)info->hdr + + info->sechdrs[info->index.str].sh_offset; + break; + } + } + + if (info->index.sym == 0) { + pr_warn("%s: module has no symbols (stripped?)\n", + info->name ?: "(missing .modinfo section or name field)"); + return -ENOEXEC; + } + + info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); + if (!info->index.mod) { + pr_warn("%s: No module found in object\n", + info->name ?: "(missing .modinfo section or name field)"); + return -ENOEXEC; + } + /* This is temporary: point mod into copy of data. */ + info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset; + + /* + * If we didn't load the .modinfo 'name' field earlier, fall back to + * on-disk struct mod 'name' field. + */ + if (!info->name) + info->name = info->mod->name; + + if (flags & MODULE_INIT_IGNORE_MODVERSIONS) + info->index.vers = 0; /* Pretend no __versions section! */ + else + info->index.vers = find_sec(info, "__versions"); + + info->index.pcpu = find_pcpusec(info); + + return 0; +} + +static int check_modinfo(struct module *mod, struct load_info *info, int flags) +{ + const char *modmagic = get_modinfo(info, "vermagic"); + int err; + + if (flags & MODULE_INIT_IGNORE_VERMAGIC) + modmagic = NULL; + + /* This is allowed: modprobe --force will invalidate it. */ + if (!modmagic) { + err = try_to_force_load(mod, "bad vermagic"); + if (err) + return err; + } else if (!same_magic(modmagic, vermagic, info->index.vers)) { + pr_err("%s: version magic '%s' should be '%s'\n", + info->name, modmagic, vermagic); + return -ENOEXEC; + } + + if (!get_modinfo(info, "intree")) { + if (!test_taint(TAINT_OOT_MODULE)) + pr_warn("%s: loading out-of-tree module taints kernel.\n", + mod->name); + add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); + } + + check_modinfo_retpoline(mod, info); + + if (get_modinfo(info, "staging")) { + add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); + pr_warn("%s: module is from the staging directory, the quality " + "is unknown, you have been warned.\n", mod->name); + } + + err = check_modinfo_livepatch(mod, info); + if (err) + return err; + + /* Set up license info based on the info section */ + set_license(mod, get_modinfo(info, "license")); + + return 0; +} + +static int find_module_sections(struct module *mod, struct load_info *info) +{ + mod->kp = section_objs(info, "__param", + sizeof(*mod->kp), &mod->num_kp); + mod->syms = section_objs(info, "__ksymtab", + sizeof(*mod->syms), &mod->num_syms); + mod->crcs = section_addr(info, "__kcrctab"); + mod->gpl_syms = section_objs(info, "__ksymtab_gpl", + sizeof(*mod->gpl_syms), + &mod->num_gpl_syms); + mod->gpl_crcs = section_addr(info, "__kcrctab_gpl"); + +#ifdef CONFIG_CONSTRUCTORS + mod->ctors = section_objs(info, ".ctors", + sizeof(*mod->ctors), &mod->num_ctors); + if (!mod->ctors) + mod->ctors = section_objs(info, ".init_array", + sizeof(*mod->ctors), &mod->num_ctors); + else if (find_sec(info, ".init_array")) { + /* + * This shouldn't happen with same compiler and binutils + * building all parts of the module. + */ + pr_warn("%s: has both .ctors and .init_array.\n", + mod->name); + return -EINVAL; + } +#endif + + mod->noinstr_text_start = section_objs(info, ".noinstr.text", 1, + &mod->noinstr_text_size); + +#ifdef CONFIG_TRACEPOINTS + mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", + sizeof(*mod->tracepoints_ptrs), + &mod->num_tracepoints); +#endif +#ifdef CONFIG_TREE_SRCU + mod->srcu_struct_ptrs = section_objs(info, "___srcu_struct_ptrs", + sizeof(*mod->srcu_struct_ptrs), + &mod->num_srcu_structs); +#endif +#ifdef CONFIG_BPF_EVENTS + mod->bpf_raw_events = section_objs(info, "__bpf_raw_tp_map", + sizeof(*mod->bpf_raw_events), + &mod->num_bpf_raw_events); +#endif +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES + mod->btf_data = any_section_objs(info, ".BTF", 1, &mod->btf_data_size); +#endif +#ifdef CONFIG_JUMP_LABEL + mod->jump_entries = section_objs(info, "__jump_table", + sizeof(*mod->jump_entries), + &mod->num_jump_entries); +#endif +#ifdef CONFIG_EVENT_TRACING + mod->trace_events = section_objs(info, "_ftrace_events", + sizeof(*mod->trace_events), + &mod->num_trace_events); + mod->trace_evals = section_objs(info, "_ftrace_eval_map", + sizeof(*mod->trace_evals), + &mod->num_trace_evals); +#endif +#ifdef CONFIG_TRACING + mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", + sizeof(*mod->trace_bprintk_fmt_start), + &mod->num_trace_bprintk_fmt); +#endif +#ifdef CONFIG_FTRACE_MCOUNT_RECORD + /* sechdrs[0].sh_size is always zero */ + mod->ftrace_callsites = section_objs(info, FTRACE_CALLSITE_SECTION, + sizeof(*mod->ftrace_callsites), + &mod->num_ftrace_callsites); +#endif +#ifdef CONFIG_FUNCTION_ERROR_INJECTION + mod->ei_funcs = section_objs(info, "_error_injection_whitelist", + sizeof(*mod->ei_funcs), + &mod->num_ei_funcs); +#endif +#ifdef CONFIG_KPROBES + mod->kprobes_text_start = section_objs(info, ".kprobes.text", 1, + &mod->kprobes_text_size); + mod->kprobe_blacklist = section_objs(info, "_kprobe_blacklist", + sizeof(unsigned long), + &mod->num_kprobe_blacklist); +#endif +#ifdef CONFIG_PRINTK_INDEX + mod->printk_index_start = section_objs(info, ".printk_index", + sizeof(*mod->printk_index_start), + &mod->printk_index_size); +#endif +#ifdef CONFIG_HAVE_STATIC_CALL_INLINE + mod->static_call_sites = section_objs(info, ".static_call_sites", + sizeof(*mod->static_call_sites), + &mod->num_static_call_sites); +#endif + mod->extable = section_objs(info, "__ex_table", + sizeof(*mod->extable), &mod->num_exentries); + + if (section_addr(info, "__obsparm")) + pr_warn("%s: Ignoring obsolete parameters\n", mod->name); + + info->debug = section_objs(info, "__dyndbg", + sizeof(*info->debug), &info->num_debug); + + return 0; +} + +static int move_module(struct module *mod, struct load_info *info) +{ + int i; + void *ptr; + + /* Do the allocs. */ + ptr = module_alloc(mod->core_layout.size); + /* + * The pointer to this block is stored in the module structure + * which is inside the block. Just mark it as not being a + * leak. + */ + kmemleak_not_leak(ptr); + if (!ptr) + return -ENOMEM; + + memset(ptr, 0, mod->core_layout.size); + mod->core_layout.base = ptr; + + if (mod->init_layout.size) { + ptr = module_alloc(mod->init_layout.size); + /* + * The pointer to this block is stored in the module structure + * which is inside the block. This block doesn't need to be + * scanned as it contains data and code that will be freed + * after the module is initialized. + */ + kmemleak_ignore(ptr); + if (!ptr) { + module_memfree(mod->core_layout.base); + return -ENOMEM; + } + memset(ptr, 0, mod->init_layout.size); + mod->init_layout.base = ptr; + } else + mod->init_layout.base = NULL; + + /* Transfer each section which specifies SHF_ALLOC */ + pr_debug("final section addresses:\n"); + for (i = 0; i < info->hdr->e_shnum; i++) { + void *dest; + Elf_Shdr *shdr = &info->sechdrs[i]; + + if (!(shdr->sh_flags & SHF_ALLOC)) + continue; + + if (shdr->sh_entsize & INIT_OFFSET_MASK) + dest = mod->init_layout.base + + (shdr->sh_entsize & ~INIT_OFFSET_MASK); + else + dest = mod->core_layout.base + shdr->sh_entsize; + + if (shdr->sh_type != SHT_NOBITS) + memcpy(dest, (void *)shdr->sh_addr, shdr->sh_size); + /* Update sh_addr to point to copy in image. */ + shdr->sh_addr = (unsigned long)dest; + pr_debug("\t0x%lx %s\n", + (long)shdr->sh_addr, info->secstrings + shdr->sh_name); + } + + return 0; +} + +static int check_module_license_and_versions(struct module *mod) +{ + int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); + + /* + * ndiswrapper is under GPL by itself, but loads proprietary modules. + * Don't use add_taint_module(), as it would prevent ndiswrapper from + * using GPL-only symbols it needs. + */ + if (strcmp(mod->name, "ndiswrapper") == 0) + add_taint(TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); + + /* driverloader was caught wrongly pretending to be under GPL */ + if (strcmp(mod->name, "driverloader") == 0) + add_taint_module(mod, TAINT_PROPRIETARY_MODULE, + LOCKDEP_NOW_UNRELIABLE); + + /* lve claims to be GPL but upstream won't provide source */ + if (strcmp(mod->name, "lve") == 0) + add_taint_module(mod, TAINT_PROPRIETARY_MODULE, + LOCKDEP_NOW_UNRELIABLE); + + if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) + pr_warn("%s: module license taints kernel.\n", mod->name); + +#ifdef CONFIG_MODVERSIONS + if ((mod->num_syms && !mod->crcs) || + (mod->num_gpl_syms && !mod->gpl_crcs)) { + return try_to_force_load(mod, + "no versions for exported symbols"); + } +#endif + return 0; +} + +static void flush_module_icache(const struct module *mod) +{ + /* + * Flush the instruction cache, since we've played with text. + * Do it before processing of module parameters, so the module + * can provide parameter accessor functions of its own. + */ + if (mod->init_layout.base) + flush_icache_range((unsigned long)mod->init_layout.base, + (unsigned long)mod->init_layout.base + + mod->init_layout.size); + flush_icache_range((unsigned long)mod->core_layout.base, + (unsigned long)mod->core_layout.base + mod->core_layout.size); +} + +int __weak module_frob_arch_sections(Elf_Ehdr *hdr, + Elf_Shdr *sechdrs, + char *secstrings, + struct module *mod) +{ + return 0; +} + +/* module_blacklist is a comma-separated list of module names */ +static char *module_blacklist; +static bool blacklisted(const char *module_name) +{ + const char *p; + size_t len; + + if (!module_blacklist) + return false; + + for (p = module_blacklist; *p; p += len) { + len = strcspn(p, ","); + if (strlen(module_name) == len && !memcmp(module_name, p, len)) + return true; + if (p[len] == ',') + len++; + } + return false; +} +core_param(module_blacklist, module_blacklist, charp, 0400); + +static struct module *layout_and_allocate(struct load_info *info, int flags) +{ + struct module *mod; + unsigned int ndx; + int err; + + err = check_modinfo(info->mod, info, flags); + if (err) + return ERR_PTR(err); + + /* Allow arches to frob section contents and sizes. */ + err = module_frob_arch_sections(info->hdr, info->sechdrs, + info->secstrings, info->mod); + if (err < 0) + return ERR_PTR(err); + + err = module_enforce_rwx_sections(info->hdr, info->sechdrs, + info->secstrings, info->mod); + if (err < 0) + return ERR_PTR(err); + + /* We will do a special allocation for per-cpu sections later. */ + info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; + + /* + * Mark ro_after_init section with SHF_RO_AFTER_INIT so that + * layout_sections() can put it in the right place. + * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. + */ + ndx = find_sec(info, ".data..ro_after_init"); + if (ndx) + info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; + /* + * Mark the __jump_table section as ro_after_init as well: these data + * structures are never modified, with the exception of entries that + * refer to code in the __init section, which are annotated as such + * at module load time. + */ + ndx = find_sec(info, "__jump_table"); + if (ndx) + info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; + + /* + * Determine total sizes, and put offsets in sh_entsize. For now + * this is done generically; there doesn't appear to be any + * special cases for the architectures. + */ + layout_sections(info->mod, info); + layout_symtab(info->mod, info); + + /* Allocate and move to the final place */ + err = move_module(info->mod, info); + if (err) + return ERR_PTR(err); + + /* Module has been copied to its final place now: return it. */ + mod = (void *)info->sechdrs[info->index.mod].sh_addr; + kmemleak_load_module(mod, info); + return mod; +} + +/* mod is no longer valid after this! */ +static void module_deallocate(struct module *mod, struct load_info *info) +{ + percpu_modfree(mod); + module_arch_freeing_init(mod); + module_memfree(mod->init_layout.base); + module_memfree(mod->core_layout.base); +} + +int __weak module_finalize(const Elf_Ehdr *hdr, + const Elf_Shdr *sechdrs, + struct module *me) +{ + return 0; +} + +static int post_relocation(struct module *mod, const struct load_info *info) +{ + /* Sort exception table now relocations are done. */ + sort_extable(mod->extable, mod->extable + mod->num_exentries); + + /* Copy relocated percpu area over. */ + percpu_modcopy(mod, (void *)info->sechdrs[info->index.pcpu].sh_addr, + info->sechdrs[info->index.pcpu].sh_size); + + /* Setup kallsyms-specific fields. */ + add_kallsyms(mod, info); + + /* Arch-specific module finalizing. */ + return module_finalize(info->hdr, info->sechdrs, mod); +} + +/* Is this module of this name done loading? No locks held. */ +static bool finished_loading(const char *name) +{ + struct module *mod; + bool ret; + + /* + * The module_mutex should not be a heavily contended lock; + * if we get the occasional sleep here, we'll go an extra iteration + * in the wait_event_interruptible(), which is harmless. + */ + sched_annotate_sleep(); + mutex_lock(&module_mutex); + mod = find_module_all(name, strlen(name), true); + ret = !mod || mod->state == MODULE_STATE_LIVE; + mutex_unlock(&module_mutex); + + return ret; +} + +/* Call module constructors. */ +static void do_mod_ctors(struct module *mod) +{ +#ifdef CONFIG_CONSTRUCTORS + unsigned long i; + + for (i = 0; i < mod->num_ctors; i++) + mod->ctors[i](); +#endif +} + +/* For freeing module_init on success, in case kallsyms traversing */ +struct mod_initfree { + struct llist_node node; + void *module_init; +}; + +static void do_free_init(struct work_struct *w) +{ + struct llist_node *pos, *n, *list; + struct mod_initfree *initfree; + + list = llist_del_all(&init_free_list); + + synchronize_rcu(); + + llist_for_each_safe(pos, n, list) { + initfree = container_of(pos, struct mod_initfree, node); + module_memfree(initfree->module_init); + kfree(initfree); + } +} + +/* + * This is where the real work happens. + * + * Keep it uninlined to provide a reliable breakpoint target, e.g. for the gdb + * helper command 'lx-symbols'. + */ +static noinline int do_init_module(struct module *mod) +{ + int ret = 0; + struct mod_initfree *freeinit; + + freeinit = kmalloc(sizeof(*freeinit), GFP_KERNEL); + if (!freeinit) { + ret = -ENOMEM; + goto fail; + } + freeinit->module_init = mod->init_layout.base; + + do_mod_ctors(mod); + /* Start the module */ + if (mod->init != NULL) + ret = do_one_initcall(mod->init); + if (ret < 0) { + goto fail_free_freeinit; + } + if (ret > 0) { + pr_warn("%s: '%s'->init suspiciously returned %d, it should " + "follow 0/-E convention\n" + "%s: loading module anyway...\n", + __func__, mod->name, ret, __func__); + dump_stack(); + } + + /* Now it's a first class citizen! */ + mod->state = MODULE_STATE_LIVE; + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_LIVE, mod); + + /* Delay uevent until module has finished its init routine */ + kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD); + + /* + * We need to finish all async code before the module init sequence + * is done. This has potential to deadlock if synchronous module + * loading is requested from async (which is not allowed!). + * + * See commit 0fdff3ec6d87 ("async, kmod: warn on synchronous + * request_module() from async workers") for more details. + */ + if (!mod->async_probe_requested) + async_synchronize_full(); + + ftrace_free_mem(mod, mod->init_layout.base, mod->init_layout.base + + mod->init_layout.size); + mutex_lock(&module_mutex); + /* Drop initial reference. */ + module_put(mod); + trim_init_extable(mod); +#ifdef CONFIG_KALLSYMS + /* Switch to core kallsyms now init is done: kallsyms may be walking! */ + rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); +#endif + module_enable_ro(mod, true); + mod_tree_remove_init(mod); + module_arch_freeing_init(mod); + mod->init_layout.base = NULL; + mod->init_layout.size = 0; + mod->init_layout.ro_size = 0; + mod->init_layout.ro_after_init_size = 0; + mod->init_layout.text_size = 0; +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES + /* .BTF is not SHF_ALLOC and will get removed, so sanitize pointer */ + mod->btf_data = NULL; +#endif + /* + * We want to free module_init, but be aware that kallsyms may be + * walking this with preempt disabled. In all the failure paths, we + * call synchronize_rcu(), but we don't want to slow down the success + * path. module_memfree() cannot be called in an interrupt, so do the + * work and call synchronize_rcu() in a work queue. + * + * Note that module_alloc() on most architectures creates W+X page + * mappings which won't be cleaned up until do_free_init() runs. Any + * code such as mark_rodata_ro() which depends on those mappings to + * be cleaned up needs to sync with the queued work - ie + * rcu_barrier() + */ + if (llist_add(&freeinit->node, &init_free_list)) + schedule_work(&init_free_wq); + + mutex_unlock(&module_mutex); + wake_up_all(&module_wq); + + return 0; + +fail_free_freeinit: + kfree(freeinit); +fail: + /* Try to protect us from buggy refcounters. */ + mod->state = MODULE_STATE_GOING; + synchronize_rcu(); + module_put(mod); + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_GOING, mod); + klp_module_going(mod); + ftrace_release_mod(mod); + free_module(mod); + wake_up_all(&module_wq); + return ret; +} + +static int may_init_module(void) +{ + if (!capable(CAP_SYS_MODULE) || modules_disabled) + return -EPERM; + + return 0; +} + +/* + * We try to place it in the list now to make sure it's unique before + * we dedicate too many resources. In particular, temporary percpu + * memory exhaustion. + */ +static int add_unformed_module(struct module *mod) +{ + int err; + struct module *old; + + mod->state = MODULE_STATE_UNFORMED; + +again: + mutex_lock(&module_mutex); + old = find_module_all(mod->name, strlen(mod->name), true); + if (old != NULL) { + if (old->state != MODULE_STATE_LIVE) { + /* Wait in case it fails to load. */ + mutex_unlock(&module_mutex); + err = wait_event_interruptible(module_wq, + finished_loading(mod->name)); + if (err) + goto out_unlocked; + goto again; + } + err = -EEXIST; + goto out; + } + mod_update_bounds(mod); + list_add_rcu(&mod->list, &modules); + mod_tree_insert(mod); + err = 0; + +out: + mutex_unlock(&module_mutex); +out_unlocked: + return err; +} + +static int complete_formation(struct module *mod, struct load_info *info) +{ + int err; + + mutex_lock(&module_mutex); + + /* Find duplicate symbols (must be called under lock). */ + err = verify_exported_symbols(mod); + if (err < 0) + goto out; + + /* This relies on module_mutex for list integrity. */ + module_bug_finalize(info->hdr, info->sechdrs, mod); + + module_enable_ro(mod, false); + module_enable_nx(mod); + module_enable_x(mod); + + /* + * Mark state as coming so strong_try_module_get() ignores us, + * but kallsyms etc. can see us. + */ + mod->state = MODULE_STATE_COMING; + mutex_unlock(&module_mutex); + + return 0; + +out: + mutex_unlock(&module_mutex); + return err; +} + +static int prepare_coming_module(struct module *mod) +{ + int err; + + ftrace_module_enable(mod); + err = klp_module_coming(mod); + if (err) + return err; + + err = blocking_notifier_call_chain_robust(&module_notify_list, + MODULE_STATE_COMING, MODULE_STATE_GOING, mod); + err = notifier_to_errno(err); + if (err) + klp_module_going(mod); + + return err; +} + +static int unknown_module_param_cb(char *param, char *val, const char *modname, + void *arg) +{ + struct module *mod = arg; + int ret; + + if (strcmp(param, "async_probe") == 0) { + mod->async_probe_requested = true; + return 0; + } + + /* Check for magic 'dyndbg' arg */ + ret = ddebug_dyndbg_module_param_cb(param, val, modname); + if (ret != 0) + pr_warn("%s: unknown parameter '%s' ignored\n", modname, param); + return 0; +} + +static void cfi_init(struct module *mod); + +/* + * Allocate and load the module: note that size of section 0 is always + * zero, and we rely on this for optional sections. + */ +static int load_module(struct load_info *info, const char __user *uargs, + int flags) +{ + struct module *mod; + long err = 0; + char *after_dashes; + + /* + * Do the signature check (if any) first. All that + * the signature check needs is info->len, it does + * not need any of the section info. That can be + * set up later. This will minimize the chances + * of a corrupt module causing problems before + * we even get to the signature check. + * + * The check will also adjust info->len by stripping + * off the sig length at the end of the module, making + * checks against info->len more correct. + */ + err = module_sig_check(info, flags); + if (err) + goto free_copy; + + /* + * Do basic sanity checks against the ELF header and + * sections. + */ + err = elf_validity_check(info); + if (err) + goto free_copy; + + /* + * Everything checks out, so set up the section info + * in the info structure. + */ + err = setup_load_info(info, flags); + if (err) + goto free_copy; + + /* + * Now that we know we have the correct module name, check + * if it's blacklisted. + */ + if (blacklisted(info->name)) { + err = -EPERM; + pr_err("Module %s is blacklisted\n", info->name); + goto free_copy; + } + + err = rewrite_section_headers(info, flags); + if (err) + goto free_copy; + + /* Check module struct version now, before we try to use module. */ + if (!check_modstruct_version(info, info->mod)) { + err = -ENOEXEC; + goto free_copy; + } + + /* Figure out module layout, and allocate all the memory. */ + mod = layout_and_allocate(info, flags); + if (IS_ERR(mod)) { + err = PTR_ERR(mod); + goto free_copy; + } + + audit_log_kern_module(mod->name); + + /* Reserve our place in the list. */ + err = add_unformed_module(mod); + if (err) + goto free_module; + +#ifdef CONFIG_MODULE_SIG + mod->sig_ok = info->sig_ok; + if (!mod->sig_ok) { + pr_notice_once("%s: module verification failed: signature " + "and/or required key missing - tainting " + "kernel\n", mod->name); + add_taint_module(mod, TAINT_UNSIGNED_MODULE, LOCKDEP_STILL_OK); + } +#endif + + /* To avoid stressing percpu allocator, do this once we're unique. */ + err = percpu_modalloc(mod, info); + if (err) + goto unlink_mod; + + /* Now module is in final location, initialize linked lists, etc. */ + err = module_unload_init(mod); + if (err) + goto unlink_mod; + + init_param_lock(mod); + + /* + * Now we've got everything in the final locations, we can + * find optional sections. + */ + err = find_module_sections(mod, info); + if (err) + goto free_unload; + + err = check_module_license_and_versions(mod); + if (err) + goto free_unload; + + /* Set up MODINFO_ATTR fields */ + setup_modinfo(mod, info); + + /* Fix up syms, so that st_value is a pointer to location. */ + err = simplify_symbols(mod, info); + if (err < 0) + goto free_modinfo; + + err = apply_relocations(mod, info); + if (err < 0) + goto free_modinfo; + + err = post_relocation(mod, info); + if (err < 0) + goto free_modinfo; + + flush_module_icache(mod); + + /* Setup CFI for the module. */ + cfi_init(mod); + + /* Now copy in args */ + mod->args = strndup_user(uargs, ~0UL >> 1); + if (IS_ERR(mod->args)) { + err = PTR_ERR(mod->args); + goto free_arch_cleanup; + } + + init_build_id(mod, info); + dynamic_debug_setup(mod, info->debug, info->num_debug); + + /* Ftrace init must be called in the MODULE_STATE_UNFORMED state */ + ftrace_module_init(mod); + + /* Finally it's fully formed, ready to start executing. */ + err = complete_formation(mod, info); + if (err) + goto ddebug_cleanup; + + err = prepare_coming_module(mod); + if (err) + goto bug_cleanup; + + /* Module is ready to execute: parsing args may do that. */ + after_dashes = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, + -32768, 32767, mod, + unknown_module_param_cb); + if (IS_ERR(after_dashes)) { + err = PTR_ERR(after_dashes); + goto coming_cleanup; + } else if (after_dashes) { + pr_warn("%s: parameters '%s' after `--' ignored\n", + mod->name, after_dashes); + } + + /* Link in to sysfs. */ + err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp); + if (err < 0) + goto coming_cleanup; + + if (is_livepatch_module(mod)) { + err = copy_module_elf(mod, info); + if (err < 0) + goto sysfs_cleanup; + } + + /* Get rid of temporary copy. */ + free_copy(info, flags); + + /* Done! */ + trace_module_load(mod); + + return do_init_module(mod); + + sysfs_cleanup: + mod_sysfs_teardown(mod); + coming_cleanup: + mod->state = MODULE_STATE_GOING; + destroy_params(mod->kp, mod->num_kp); + blocking_notifier_call_chain(&module_notify_list, + MODULE_STATE_GOING, mod); + klp_module_going(mod); + bug_cleanup: + mod->state = MODULE_STATE_GOING; + /* module_bug_cleanup needs module_mutex protection */ + mutex_lock(&module_mutex); + module_bug_cleanup(mod); + mutex_unlock(&module_mutex); + + ddebug_cleanup: + ftrace_release_mod(mod); + dynamic_debug_remove(mod, info->debug); + synchronize_rcu(); + kfree(mod->args); + free_arch_cleanup: + cfi_cleanup(mod); + module_arch_cleanup(mod); + free_modinfo: + free_modinfo(mod); + free_unload: + module_unload_free(mod); + unlink_mod: + mutex_lock(&module_mutex); + /* Unlink carefully: kallsyms could be walking list. */ + list_del_rcu(&mod->list); + mod_tree_remove(mod); + wake_up_all(&module_wq); + /* Wait for RCU-sched synchronizing before releasing mod->list. */ + synchronize_rcu(); + mutex_unlock(&module_mutex); + free_module: + /* Free lock-classes; relies on the preceding sync_rcu() */ + lockdep_free_key_range(mod->core_layout.base, mod->core_layout.size); + + module_deallocate(mod, info); + free_copy: + free_copy(info, flags); + return err; +} + +SYSCALL_DEFINE3(init_module, void __user *, umod, + unsigned long, len, const char __user *, uargs) +{ + int err; + struct load_info info = { }; + + err = may_init_module(); + if (err) + return err; + + pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n", + umod, len, uargs); + + err = copy_module_from_user(umod, len, &info); + if (err) + return err; + + return load_module(&info, uargs, 0); +} + +SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) +{ + struct load_info info = { }; + void *buf = NULL; + int len; + int err; + + err = may_init_module(); + if (err) + return err; + + pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); + + if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS + |MODULE_INIT_IGNORE_VERMAGIC + |MODULE_INIT_COMPRESSED_FILE)) + return -EINVAL; + + len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL, + READING_MODULE); + if (len < 0) + return len; + + if (flags & MODULE_INIT_COMPRESSED_FILE) { + err = module_decompress(&info, buf, len); + vfree(buf); /* compressed data is no longer needed */ + if (err) + return err; + } else { + info.hdr = buf; + info.len = len; + } + + return load_module(&info, uargs, flags); +} + +static inline int within(unsigned long addr, void *start, unsigned long size) +{ + return ((void *)addr >= start && (void *)addr < start + size); +} + +#ifdef CONFIG_KALLSYMS +/* + * This ignores the intensely annoying "mapping symbols" found + * in ARM ELF files: $a, $t and $d. + */ +static inline int is_arm_mapping_symbol(const char *str) +{ + if (str[0] == '.' && str[1] == 'L') + return true; + return str[0] == '$' && strchr("axtd", str[1]) + && (str[2] == '\0' || str[2] == '.'); +} + +static const char *kallsyms_symbol_name(struct mod_kallsyms *kallsyms, unsigned int symnum) +{ + return kallsyms->strtab + kallsyms->symtab[symnum].st_name; +} + +/* + * Given a module and address, find the corresponding symbol and return its name + * while providing its size and offset if needed. + */ +static const char *find_kallsyms_symbol(struct module *mod, + unsigned long addr, + unsigned long *size, + unsigned long *offset) +{ + unsigned int i, best = 0; + unsigned long nextval, bestval; + struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); + + /* At worse, next value is at end of module */ + if (within_module_init(addr, mod)) + nextval = (unsigned long)mod->init_layout.base+mod->init_layout.text_size; + else + nextval = (unsigned long)mod->core_layout.base+mod->core_layout.text_size; + + bestval = kallsyms_symbol_value(&kallsyms->symtab[best]); + + /* + * Scan for closest preceding symbol, and next symbol. (ELF + * starts real symbols at 1). + */ + for (i = 1; i < kallsyms->num_symtab; i++) { + const Elf_Sym *sym = &kallsyms->symtab[i]; + unsigned long thisval = kallsyms_symbol_value(sym); + + if (sym->st_shndx == SHN_UNDEF) + continue; + + /* + * We ignore unnamed symbols: they're uninformative + * and inserted at a whim. + */ + if (*kallsyms_symbol_name(kallsyms, i) == '\0' + || is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i))) + continue; + + if (thisval <= addr && thisval > bestval) { + best = i; + bestval = thisval; + } + if (thisval > addr && thisval < nextval) + nextval = thisval; + } + + if (!best) + return NULL; + + if (size) + *size = nextval - bestval; + if (offset) + *offset = addr - bestval; + + return kallsyms_symbol_name(kallsyms, best); +} + +void * __weak dereference_module_function_descriptor(struct module *mod, + void *ptr) +{ + return ptr; +} + +/* + * For kallsyms to ask for address resolution. NULL means not found. Careful + * not to lock to avoid deadlock on oopses, simply disable preemption. + */ +const char *module_address_lookup(unsigned long addr, + unsigned long *size, + unsigned long *offset, + char **modname, + const unsigned char **modbuildid, + char *namebuf) +{ + const char *ret = NULL; + struct module *mod; + + preempt_disable(); + mod = __module_address(addr); + if (mod) { + if (modname) + *modname = mod->name; + if (modbuildid) { +#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID) + *modbuildid = mod->build_id; +#else + *modbuildid = NULL; +#endif + } + + ret = find_kallsyms_symbol(mod, addr, size, offset); + } + /* Make a copy in here where it's safe */ + if (ret) { + strncpy(namebuf, ret, KSYM_NAME_LEN - 1); + ret = namebuf; + } + preempt_enable(); + + return ret; +} + +int lookup_module_symbol_name(unsigned long addr, char *symname) +{ + struct module *mod; + + preempt_disable(); + list_for_each_entry_rcu(mod, &modules, list) { + if (mod->state == MODULE_STATE_UNFORMED) + continue; + if (within_module(addr, mod)) { + const char *sym; + + sym = find_kallsyms_symbol(mod, addr, NULL, NULL); + if (!sym) + goto out; + + strlcpy(symname, sym, KSYM_NAME_LEN); + preempt_enable(); + return 0; + } + } +out: + preempt_enable(); + return -ERANGE; +} + +int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, + unsigned long *offset, char *modname, char *name) +{ + struct module *mod; + + preempt_disable(); + list_for_each_entry_rcu(mod, &modules, list) { + if (mod->state == MODULE_STATE_UNFORMED) + continue; + if (within_module(addr, mod)) { + const char *sym; + + sym = find_kallsyms_symbol(mod, addr, size, offset); + if (!sym) + goto out; + if (modname) + strlcpy(modname, mod->name, MODULE_NAME_LEN); + if (name) + strlcpy(name, sym, KSYM_NAME_LEN); + preempt_enable(); + return 0; + } + } +out: + preempt_enable(); + return -ERANGE; +} + +int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, + char *name, char *module_name, int *exported) +{ + struct module *mod; + + preempt_disable(); + list_for_each_entry_rcu(mod, &modules, list) { + struct mod_kallsyms *kallsyms; + + if (mod->state == MODULE_STATE_UNFORMED) + continue; + kallsyms = rcu_dereference_sched(mod->kallsyms); + if (symnum < kallsyms->num_symtab) { + const Elf_Sym *sym = &kallsyms->symtab[symnum]; + + *value = kallsyms_symbol_value(sym); + *type = kallsyms->typetab[symnum]; + strlcpy(name, kallsyms_symbol_name(kallsyms, symnum), KSYM_NAME_LEN); + strlcpy(module_name, mod->name, MODULE_NAME_LEN); + *exported = is_exported(name, *value, mod); + preempt_enable(); + return 0; + } + symnum -= kallsyms->num_symtab; + } + preempt_enable(); + return -ERANGE; +} + +/* Given a module and name of symbol, find and return the symbol's value */ +static unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name) +{ + unsigned int i; + struct mod_kallsyms *kallsyms = rcu_dereference_sched(mod->kallsyms); + + for (i = 0; i < kallsyms->num_symtab; i++) { + const Elf_Sym *sym = &kallsyms->symtab[i]; + + if (strcmp(name, kallsyms_symbol_name(kallsyms, i)) == 0 && + sym->st_shndx != SHN_UNDEF) + return kallsyms_symbol_value(sym); + } + return 0; +} + +/* Look for this name: can be of form module:name. */ +unsigned long module_kallsyms_lookup_name(const char *name) +{ + struct module *mod; + char *colon; + unsigned long ret = 0; + + /* Don't lock: we're in enough trouble already. */ + preempt_disable(); + if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) { + if ((mod = find_module_all(name, colon - name, false)) != NULL) + ret = find_kallsyms_symbol_value(mod, colon+1); + } else { + list_for_each_entry_rcu(mod, &modules, list) { + if (mod->state == MODULE_STATE_UNFORMED) + continue; + if ((ret = find_kallsyms_symbol_value(mod, name)) != 0) + break; + } + } + preempt_enable(); + return ret; +} + +#ifdef CONFIG_LIVEPATCH +int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, + struct module *, unsigned long), + void *data) +{ + struct module *mod; + unsigned int i; + int ret = 0; + + mutex_lock(&module_mutex); + list_for_each_entry(mod, &modules, list) { + /* We hold module_mutex: no need for rcu_dereference_sched */ + struct mod_kallsyms *kallsyms = mod->kallsyms; + + if (mod->state == MODULE_STATE_UNFORMED) + continue; + for (i = 0; i < kallsyms->num_symtab; i++) { + const Elf_Sym *sym = &kallsyms->symtab[i]; + + if (sym->st_shndx == SHN_UNDEF) + continue; + + ret = fn(data, kallsyms_symbol_name(kallsyms, i), + mod, kallsyms_symbol_value(sym)); + if (ret != 0) + goto out; + + cond_resched(); + } + } +out: + mutex_unlock(&module_mutex); + return ret; +} +#endif /* CONFIG_LIVEPATCH */ +#endif /* CONFIG_KALLSYMS */ + +static void cfi_init(struct module *mod) +{ +#ifdef CONFIG_CFI_CLANG + initcall_t *init; + exitcall_t *exit; + + rcu_read_lock_sched(); + mod->cfi_check = (cfi_check_fn) + find_kallsyms_symbol_value(mod, "__cfi_check"); + init = (initcall_t *) + find_kallsyms_symbol_value(mod, "__cfi_jt_init_module"); + exit = (exitcall_t *) + find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module"); + rcu_read_unlock_sched(); + + /* Fix init/exit functions to point to the CFI jump table */ + if (init) + mod->init = *init; +#ifdef CONFIG_MODULE_UNLOAD + if (exit) + mod->exit = *exit; +#endif + + cfi_module_add(mod, module_addr_min); +#endif +} + +static void cfi_cleanup(struct module *mod) +{ +#ifdef CONFIG_CFI_CLANG + cfi_module_remove(mod, module_addr_min); +#endif +} + +/* Maximum number of characters written by module_flags() */ +#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) + +/* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ +static char *module_flags(struct module *mod, char *buf) +{ + int bx = 0; + + BUG_ON(mod->state == MODULE_STATE_UNFORMED); + if (mod->taints || + mod->state == MODULE_STATE_GOING || + mod->state == MODULE_STATE_COMING) { + buf[bx++] = '('; + bx += module_flags_taint(mod, buf + bx); + /* Show a - for module-is-being-unloaded */ + if (mod->state == MODULE_STATE_GOING) + buf[bx++] = '-'; + /* Show a + for module-is-being-loaded */ + if (mod->state == MODULE_STATE_COMING) + buf[bx++] = '+'; + buf[bx++] = ')'; + } + buf[bx] = '\0'; + + return buf; +} + +#ifdef CONFIG_PROC_FS +/* Called by the /proc file system to return a list of modules. */ +static void *m_start(struct seq_file *m, loff_t *pos) +{ + mutex_lock(&module_mutex); + return seq_list_start(&modules, *pos); +} + +static void *m_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &modules, pos); +} + +static void m_stop(struct seq_file *m, void *p) +{ + mutex_unlock(&module_mutex); +} + +static int m_show(struct seq_file *m, void *p) +{ + struct module *mod = list_entry(p, struct module, list); + char buf[MODULE_FLAGS_BUF_SIZE]; + void *value; + + /* We always ignore unformed modules. */ + if (mod->state == MODULE_STATE_UNFORMED) + return 0; + + seq_printf(m, "%s %u", + mod->name, mod->init_layout.size + mod->core_layout.size); + print_unload_info(m, mod); + + /* Informative for users. */ + seq_printf(m, " %s", + mod->state == MODULE_STATE_GOING ? "Unloading" : + mod->state == MODULE_STATE_COMING ? "Loading" : + "Live"); + /* Used by oprofile and other similar tools. */ + value = m->private ? NULL : mod->core_layout.base; + seq_printf(m, " 0x%px", value); + + /* Taints info */ + if (mod->taints) + seq_printf(m, " %s", module_flags(mod, buf)); + + seq_puts(m, "\n"); + return 0; +} + +/* + * Format: modulename size refcount deps address + * + * Where refcount is a number or -, and deps is a comma-separated list + * of depends or -. + */ +static const struct seq_operations modules_op = { + .start = m_start, + .next = m_next, + .stop = m_stop, + .show = m_show +}; + +/* + * This also sets the "private" pointer to non-NULL if the + * kernel pointers should be hidden (so you can just test + * "m->private" to see if you should keep the values private). + * + * We use the same logic as for /proc/kallsyms. + */ +static int modules_open(struct inode *inode, struct file *file) +{ + int err = seq_open(file, &modules_op); + + if (!err) { + struct seq_file *m = file->private_data; + m->private = kallsyms_show_value(file->f_cred) ? NULL : (void *)8ul; + } + + return err; +} + +static const struct proc_ops modules_proc_ops = { + .proc_flags = PROC_ENTRY_PERMANENT, + .proc_open = modules_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = seq_release, +}; + +static int __init proc_modules_init(void) +{ + proc_create("modules", 0, NULL, &modules_proc_ops); + return 0; +} +module_init(proc_modules_init); +#endif + +/* Given an address, look for it in the module exception tables. */ +const struct exception_table_entry *search_module_extables(unsigned long addr) +{ + const struct exception_table_entry *e = NULL; + struct module *mod; + + preempt_disable(); + mod = __module_address(addr); + if (!mod) + goto out; + + if (!mod->num_exentries) + goto out; + + e = search_extable(mod->extable, + mod->num_exentries, + addr); +out: + preempt_enable(); + + /* + * Now, if we found one, we are running inside it now, hence + * we cannot unload the module, hence no refcnt needed. + */ + return e; +} + +/** + * is_module_address() - is this address inside a module? + * @addr: the address to check. + * + * See is_module_text_address() if you simply want to see if the address + * is code (not data). + */ +bool is_module_address(unsigned long addr) +{ + bool ret; + + preempt_disable(); + ret = __module_address(addr) != NULL; + preempt_enable(); + + return ret; +} + +/** + * __module_address() - get the module which contains an address. + * @addr: the address. + * + * Must be called with preempt disabled or module mutex held so that + * module doesn't get freed during this. + */ +struct module *__module_address(unsigned long addr) +{ + struct module *mod; + + if (addr < module_addr_min || addr > module_addr_max) + return NULL; + + module_assert_mutex_or_preempt(); + + mod = mod_find(addr); + if (mod) { + BUG_ON(!within_module(addr, mod)); + if (mod->state == MODULE_STATE_UNFORMED) + mod = NULL; + } + return mod; +} + +/** + * is_module_text_address() - is this address inside module code? + * @addr: the address to check. + * + * See is_module_address() if you simply want to see if the address is + * anywhere in a module. See kernel_text_address() for testing if an + * address corresponds to kernel or module code. + */ +bool is_module_text_address(unsigned long addr) +{ + bool ret; + + preempt_disable(); + ret = __module_text_address(addr) != NULL; + preempt_enable(); + + return ret; +} + +/** + * __module_text_address() - get the module whose code contains an address. + * @addr: the address. + * + * Must be called with preempt disabled or module mutex held so that + * module doesn't get freed during this. + */ +struct module *__module_text_address(unsigned long addr) +{ + struct module *mod = __module_address(addr); + if (mod) { + /* Make sure it's within the text section. */ + if (!within(addr, mod->init_layout.base, mod->init_layout.text_size) + && !within(addr, mod->core_layout.base, mod->core_layout.text_size)) + mod = NULL; + } + return mod; +} + +/* Don't grab lock, we're oopsing. */ +void print_modules(void) +{ + struct module *mod; + char buf[MODULE_FLAGS_BUF_SIZE]; + + printk(KERN_DEFAULT "Modules linked in:"); + /* Most callers should already have preempt disabled, but make sure */ + preempt_disable(); + list_for_each_entry_rcu(mod, &modules, list) { + if (mod->state == MODULE_STATE_UNFORMED) + continue; + pr_cont(" %s%s", mod->name, module_flags(mod, buf)); + } + preempt_enable(); + if (last_unloaded_module[0]) + pr_cont(" [last unloaded: %s]", last_unloaded_module); + pr_cont("\n"); +} + +#ifdef CONFIG_MODVERSIONS +/* + * Generate the signature for all relevant module structures here. + * If these change, we don't want to try to parse the module. + */ +void module_layout(struct module *mod, + struct modversion_info *ver, + struct kernel_param *kp, + struct kernel_symbol *ks, + struct tracepoint * const *tp) +{ +} +EXPORT_SYMBOL(module_layout); +#endif diff --git a/kernel/module/signing.c b/kernel/module/signing.c new file mode 100644 index 0000000000000..8aeb6d2ee94b1 --- /dev/null +++ b/kernel/module/signing.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Module signature checker + * + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include +#include +#include +#include +#include "internal.h" + +/* + * Verify the signature on a module. + */ +int mod_verify_sig(const void *mod, struct load_info *info) +{ + struct module_signature ms; + size_t sig_len, modlen = info->len; + int ret; + + pr_devel("==>%s(,%zu)\n", __func__, modlen); + + if (modlen <= sizeof(ms)) + return -EBADMSG; + + memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms)); + + ret = mod_check_sig(&ms, modlen, "module"); + if (ret) + return ret; + + sig_len = be32_to_cpu(ms.sig_len); + modlen -= sig_len + sizeof(ms); + info->len = modlen; + + return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, + VERIFY_USE_SECONDARY_KEYRING, + VERIFYING_MODULE_SIGNATURE, + NULL, NULL); +} diff --git a/kernel/module_decompress.c b/kernel/module_decompress.c deleted file mode 100644 index ffef98a203204..0000000000000 --- a/kernel/module_decompress.c +++ /dev/null @@ -1,273 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Copyright 2021 Google LLC. - */ - -#include -#include -#include -#include -#include -#include -#include -#include - -#include "module-internal.h" - -static int module_extend_max_pages(struct load_info *info, unsigned int extent) -{ - struct page **new_pages; - - new_pages = kvmalloc_array(info->max_pages + extent, - sizeof(info->pages), GFP_KERNEL); - if (!new_pages) - return -ENOMEM; - - memcpy(new_pages, info->pages, info->max_pages * sizeof(info->pages)); - kvfree(info->pages); - info->pages = new_pages; - info->max_pages += extent; - - return 0; -} - -static struct page *module_get_next_page(struct load_info *info) -{ - struct page *page; - int error; - - if (info->max_pages == info->used_pages) { - error = module_extend_max_pages(info, info->used_pages); - if (error) - return ERR_PTR(error); - } - - page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); - if (!page) - return ERR_PTR(-ENOMEM); - - info->pages[info->used_pages++] = page; - return page; -} - -#ifdef CONFIG_MODULE_COMPRESS_GZIP -#include -#define MODULE_COMPRESSION gzip -#define MODULE_DECOMPRESS_FN module_gzip_decompress - -/* - * Calculate length of the header which consists of signature, header - * flags, time stamp and operating system ID (10 bytes total), plus - * an optional filename. - */ -static size_t module_gzip_header_len(const u8 *buf, size_t size) -{ - const u8 signature[] = { 0x1f, 0x8b, 0x08 }; - size_t len = 10; - - if (size < len || memcmp(buf, signature, sizeof(signature))) - return 0; - - if (buf[3] & 0x08) { - do { - /* - * If we can't find the end of the file name we must - * be dealing with a corrupted file. - */ - if (len == size) - return 0; - } while (buf[len++] != '\0'); - } - - return len; -} - -static ssize_t module_gzip_decompress(struct load_info *info, - const void *buf, size_t size) -{ - struct z_stream_s s = { 0 }; - size_t new_size = 0; - size_t gzip_hdr_len; - ssize_t retval; - int rc; - - gzip_hdr_len = module_gzip_header_len(buf, size); - if (!gzip_hdr_len) { - pr_err("not a gzip compressed module\n"); - return -EINVAL; - } - - s.next_in = buf + gzip_hdr_len; - s.avail_in = size - gzip_hdr_len; - - s.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); - if (!s.workspace) - return -ENOMEM; - - rc = zlib_inflateInit2(&s, -MAX_WBITS); - if (rc != Z_OK) { - pr_err("failed to initialize decompressor: %d\n", rc); - retval = -EINVAL; - goto out; - } - - do { - struct page *page = module_get_next_page(info); - if (!page) { - retval = -ENOMEM; - goto out_inflate_end; - } - - s.next_out = kmap(page); - s.avail_out = PAGE_SIZE; - rc = zlib_inflate(&s, 0); - kunmap(page); - - new_size += PAGE_SIZE - s.avail_out; - } while (rc == Z_OK); - - if (rc != Z_STREAM_END) { - pr_err("decompression failed with status %d\n", rc); - retval = -EINVAL; - goto out_inflate_end; - } - - retval = new_size; - -out_inflate_end: - zlib_inflateEnd(&s); -out: - kfree(s.workspace); - return retval; -} -#elif CONFIG_MODULE_COMPRESS_XZ -#include -#define MODULE_COMPRESSION xz -#define MODULE_DECOMPRESS_FN module_xz_decompress - -static ssize_t module_xz_decompress(struct load_info *info, - const void *buf, size_t size) -{ - static const u8 signature[] = { 0xfd, '7', 'z', 'X', 'Z', 0 }; - struct xz_dec *xz_dec; - struct xz_buf xz_buf; - enum xz_ret xz_ret; - size_t new_size = 0; - ssize_t retval; - - if (size < sizeof(signature) || - memcmp(buf, signature, sizeof(signature))) { - pr_err("not an xz compressed module\n"); - return -EINVAL; - } - - xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1); - if (!xz_dec) - return -ENOMEM; - - xz_buf.in_size = size; - xz_buf.in = buf; - xz_buf.in_pos = 0; - - do { - struct page *page = module_get_next_page(info); - if (!page) { - retval = -ENOMEM; - goto out; - } - - xz_buf.out = kmap(page); - xz_buf.out_pos = 0; - xz_buf.out_size = PAGE_SIZE; - xz_ret = xz_dec_run(xz_dec, &xz_buf); - kunmap(page); - - new_size += xz_buf.out_pos; - } while (xz_buf.out_pos == PAGE_SIZE && xz_ret == XZ_OK); - - if (xz_ret != XZ_STREAM_END) { - pr_err("decompression failed with status %d\n", xz_ret); - retval = -EINVAL; - goto out; - } - - retval = new_size; - - out: - xz_dec_end(xz_dec); - return retval; -} -#else -#error "Unexpected configuration for CONFIG_MODULE_DECOMPRESS" -#endif - -int module_decompress(struct load_info *info, const void *buf, size_t size) -{ - unsigned int n_pages; - ssize_t data_size; - int error; - - /* - * Start with number of pages twice as big as needed for - * compressed data. - */ - n_pages = DIV_ROUND_UP(size, PAGE_SIZE) * 2; - error = module_extend_max_pages(info, n_pages); - - data_size = MODULE_DECOMPRESS_FN(info, buf, size); - if (data_size < 0) { - error = data_size; - goto err; - } - - info->hdr = vmap(info->pages, info->used_pages, VM_MAP, PAGE_KERNEL); - if (!info->hdr) { - error = -ENOMEM; - goto err; - } - - info->len = data_size; - return 0; - -err: - module_decompress_cleanup(info); - return error; -} - -void module_decompress_cleanup(struct load_info *info) -{ - int i; - - if (info->hdr) - vunmap(info->hdr); - - for (i = 0; i < info->used_pages; i++) - __free_page(info->pages[i]); - - kvfree(info->pages); - - info->pages = NULL; - info->max_pages = info->used_pages = 0; -} - -#ifdef CONFIG_SYSFS -static ssize_t compression_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) -{ - return sysfs_emit(buf, "%s\n", __stringify(MODULE_COMPRESSION)); -} -static struct kobj_attribute module_compression_attr = __ATTR_RO(compression); - -static int __init module_decompress_sysfs_init(void) -{ - int error; - - error = sysfs_create_file(&module_kset->kobj, - &module_compression_attr.attr); - if (error) - pr_warn("Failed to create 'compression' attribute"); - - return 0; -} -late_initcall(module_decompress_sysfs_init); -#endif diff --git a/kernel/module_signing.c b/kernel/module_signing.c deleted file mode 100644 index 8723ae70ea1fe..0000000000000 --- a/kernel/module_signing.c +++ /dev/null @@ -1,45 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* Module signature checker - * - * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - */ - -#include -#include -#include -#include -#include -#include -#include -#include "module-internal.h" - -/* - * Verify the signature on a module. - */ -int mod_verify_sig(const void *mod, struct load_info *info) -{ - struct module_signature ms; - size_t sig_len, modlen = info->len; - int ret; - - pr_devel("==>%s(,%zu)\n", __func__, modlen); - - if (modlen <= sizeof(ms)) - return -EBADMSG; - - memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms)); - - ret = mod_check_sig(&ms, modlen, "module"); - if (ret) - return ret; - - sig_len = be32_to_cpu(ms.sig_len); - modlen -= sig_len + sizeof(ms); - info->len = modlen; - - return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len, - VERIFY_USE_SECONDARY_KEYRING, - VERIFYING_MODULE_SIGNATURE, - NULL, NULL); -}