mm/execmem, arch: convert simple overrides of module_alloc to execmem

Several architectures override module_alloc() only to define address
range for code allocations different than VMALLOC address space.

Provide a generic implementation in execmem that uses the parameters for
address space ranges, required alignment and page protections provided
by architectures.

The architectures must fill execmem_info structure and implement
execmem_arch_setup() that returns a pointer to that structure. This way the
execmem initialization won't be called from every architecture, but rather
from a central place, namely a core_initcall() in execmem.

The execmem provides execmem_alloc() API that wraps __vmalloc_node_range()
with the parameters defined by the architectures.  If an architecture does
not implement execmem_arch_setup(), execmem_alloc() will fall back to
module_alloc().

Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

diff --git a/arch/loongarch/kernel/module.c b/arch/loongarch/kernel/module.c
index c7d0338d12c15bc15634f69191eb20a44a1d42c5..ca6dd7ea161014179490275eddb1b0e3ae583ecf 100644 (file)
--- a/arch/loongarch/kernel/module.c
+++ b/arch/loongarch/kernel/module.c
@@ -18,6 +18,7 @@
 #include <linux/ftrace.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
+#include <linux/execmem.h>
 #include <asm/alternative.h>
 #include <asm/inst.h>
 #include <asm/unwind.h>
@@ -490,10 +491,22 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
        return 0;
 }
 
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
 {
-       return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-                       GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE, __builtin_return_address(0));
+       execmem_info = (struct execmem_info){
+               .ranges = {
+                       [EXECMEM_DEFAULT] = {
+                               .start  = MODULES_VADDR,
+                               .end    = MODULES_END,
+                               .pgprot = PAGE_KERNEL,
+                               .alignment = 1,
+                       },
+               },
+       };
+
+       return &execmem_info;
 }
 
 static void module_init_ftrace_plt(const Elf_Ehdr *hdr,

diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index 9a6c9601490434b8a062cf063a24924f39175770..59225a3cf918b77ed481011f770657204c695a04 100644 (file)
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -20,6 +20,7 @@
 #include <linux/kernel.h>
 #include <linux/spinlock.h>
 #include <linux/jump_label.h>
+#include <linux/execmem.h>
 #include <asm/jump_label.h>
 
 struct mips_hi16 {
@@ -32,11 +33,22 @@ static LIST_HEAD(dbe_list);
 static DEFINE_SPINLOCK(dbe_lock);
 
 #ifdef MODULES_VADDR
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
 {
-       return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-                               GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
-                               __builtin_return_address(0));
+       execmem_info = (struct execmem_info){
+               .ranges = {
+                       [EXECMEM_DEFAULT] = {
+                               .start  = MODULES_VADDR,
+                               .end    = MODULES_END,
+                               .pgprot = PAGE_KERNEL,
+                               .alignment = 1,
+                       },
+               },
+       };
+
+       return &execmem_info;
 }
 #endif
 

diff --git a/arch/nios2/kernel/module.c b/arch/nios2/kernel/module.c
index 9c97b751385334a354821c85ca541732c8e272f7..0d1ee86631fc7693876f25b05b4adc4e2ddd74c0 100644 (file)
--- a/arch/nios2/kernel/module.c
+++ b/arch/nios2/kernel/module.c
@@ -18,15 +18,26 @@
 #include <linux/fs.h>
 #include <linux/string.h>
 #include <linux/kernel.h>
+#include <linux/execmem.h>
 
 #include <asm/cacheflush.h>
 
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
 {
-       return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-                                   GFP_KERNEL, PAGE_KERNEL_EXEC,
-                                   VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
-                                   __builtin_return_address(0));
+       execmem_info = (struct execmem_info){
+               .ranges = {
+                       [EXECMEM_DEFAULT] = {
+                               .start  = MODULES_VADDR,
+                               .end    = MODULES_END,
+                               .pgprot = PAGE_KERNEL_EXEC,
+                               .alignment = 1,
+                       },
+               },
+       };
+
+       return &execmem_info;
 }
 
 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,

diff --git a/arch/parisc/kernel/module.c b/arch/parisc/kernel/module.c
index d214bbe3c2afc19b436618f729ece46d3ea3199e..bdfa85e10c1be5c841d299cdbd6d8ed5421f2e8d 100644 (file)
--- a/arch/parisc/kernel/module.c
+++ b/arch/parisc/kernel/module.c
@@ -49,6 +49,7 @@
 #include <linux/bug.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
+#include <linux/execmem.h>
 
 #include <asm/unwind.h>
 #include <asm/sections.h>
@@ -173,15 +174,22 @@ static inline int reassemble_22(int as22)
                ((as22 & 0x0003ff) << 3));
 }
 
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
 {
-       /* using RWX means less protection for modules, but it's
-        * easier than trying to map the text, data, init_text and
-        * init_data correctly */
-       return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
-                                   GFP_KERNEL,
-                                   PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
-                                   __builtin_return_address(0));
+       execmem_info = (struct execmem_info){
+               .ranges = {
+                       [EXECMEM_DEFAULT] = {
+                               .start  = VMALLOC_START,
+                               .end    = VMALLOC_END,
+                               .pgprot = PAGE_KERNEL_RWX,
+                               .alignment = 1,
+                       },
+               },
+       };
+
+       return &execmem_info;
 }
 
 #ifndef CONFIG_64BIT

diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
index 5e5a82644451e16d8bdfe229e2ce89b4c389c31e..182904127ba06e083740a7c0dc58253186a5cbe5 100644 (file)
--- a/arch/riscv/kernel/module.c
+++ b/arch/riscv/kernel/module.c
@@ -14,6 +14,7 @@
 #include <linux/vmalloc.h>
 #include <linux/sizes.h>
 #include <linux/pgtable.h>
+#include <linux/execmem.h>
 #include <asm/alternative.h>
 #include <asm/sections.h>
 
@@ -906,13 +907,22 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
 }
 
 #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
-void *module_alloc(unsigned long size)
-{
-       return __vmalloc_node_range(size, 1, MODULES_VADDR,
-                                   MODULES_END, GFP_KERNEL,
-                                   PAGE_KERNEL, VM_FLUSH_RESET_PERMS,
-                                   NUMA_NO_NODE,
-                                   __builtin_return_address(0));
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
+{
+       execmem_info = (struct execmem_info){
+               .ranges = {
+                       [EXECMEM_DEFAULT] = {
+                               .start  = MODULES_VADDR,
+                               .end    = MODULES_END,
+                               .pgprot = PAGE_KERNEL,
+                               .alignment = 1,
+                       },
+               },
+       };
+
+       return &execmem_info;
 }
 #endif
 

diff --git a/arch/sparc/kernel/module.c b/arch/sparc/kernel/module.c
index d37adb2a0b54f73b7901c53378bc049766efa3f3..8b7ee45defc3d13b111073ed883af28b036afd76 100644 (file)
--- a/arch/sparc/kernel/module.c
+++ b/arch/sparc/kernel/module.c
@@ -14,6 +14,7 @@
 #include <linux/string.h>
 #include <linux/ctype.h>
 #include <linux/mm.h>
+#include <linux/execmem.h>
 
 #include <asm/processor.h>
 #include <asm/spitfire.h>
@@ -21,11 +22,22 @@
 
 #include "entry.h"
 
-void *module_alloc(unsigned long size)
+static struct execmem_info execmem_info __ro_after_init;
+
+struct execmem_info __init *execmem_arch_setup(void)
 {
-       return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
-                               GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
-                               __builtin_return_address(0));
+       execmem_info = (struct execmem_info){
+               .ranges = {
+                       [EXECMEM_DEFAULT] = {
+                               .start  = MODULES_VADDR,
+                               .end    = MODULES_END,
+                               .pgprot = PAGE_KERNEL,
+                               .alignment = 1,
+                       },
+               },
+       };
+
+       return &execmem_info;
 }
 
 /* Make generic code ignore STT_REGISTER dummy undefined symbols.  */

diff --git a/include/linux/execmem.h b/include/linux/execmem.h
index 8eebc8ef66e7a9d3a9ee4f1b15edb662daae74ee..96fc5925846724751f8add5a18c614272532c21f 100644 (file)
--- a/include/linux/execmem.h
+++ b/include/linux/execmem.h
@@ -33,6 +33,47 @@ enum execmem_type {
        EXECMEM_TYPE_MAX,
 };
 
+/**
+ * struct execmem_range - definition of an address space suitable for code and
+ *                       related data allocations
+ * @start:     address space start
+ * @end:       address space end (inclusive)
+ * @pgprot:    permissions for memory in this address space
+ * @alignment: alignment required for text allocations
+ */
+struct execmem_range {
+       unsigned long   start;
+       unsigned long   end;
+       pgprot_t        pgprot;
+       unsigned int    alignment;
+};
+
+/**
+ * struct execmem_info - architecture parameters for code allocations
+ * @ranges: array of parameter sets defining architecture specific
+ * parameters for executable memory allocations. The ranges that are not
+ * explicitly initialized by an architecture use parameters defined for
+ * @EXECMEM_DEFAULT.
+ */
+struct execmem_info {
+       struct execmem_range    ranges[EXECMEM_TYPE_MAX];
+};
+
+/**
+ * execmem_arch_setup - define parameters for allocations of executable memory
+ *
+ * A hook for architectures to define parameters for allocations of
+ * executable memory. These parameters should be filled into the
+ * @execmem_info structure.
+ *
+ * For architectures that do not implement this method a default set of
+ * parameters will be used
+ *
+ * Return: a structure defining architecture parameters and restrictions
+ * for allocations of executable memory
+ */
+struct execmem_info *execmem_arch_setup(void);
+
 /**
  * execmem_alloc - allocate executable memory
  * @type: type of the allocation
@@ -54,4 +95,10 @@ void *execmem_alloc(enum execmem_type type, size_t size);
  */
 void execmem_free(void *ptr);
 
+#ifdef CONFIG_EXECMEM
+void execmem_init(void);
+#else
+static inline void execmem_init(void) {}
+#endif
+
 #endif /* _LINUX_EXECMEM_ALLOC_H */

diff --git a/mm/execmem.c b/mm/execmem.c
index 480adc69b20d579dc0412a8b5c595e8d723148ad..80e61c1e7319a09921f448f37246dfce47925144 100644 (file)
--- a/mm/execmem.c
+++ b/mm/execmem.c
@@ -11,14 +11,30 @@
 #include <linux/execmem.h>
 #include <linux/moduleloader.h>
 
-static void *__execmem_alloc(size_t size)
+static struct execmem_info *execmem_info __ro_after_init;
+
+static void *__execmem_alloc(struct execmem_range *range, size_t size)
 {
-       return module_alloc(size);
+       unsigned long start = range->start;
+       unsigned long end = range->end;
+       unsigned int align = range->alignment;
+       pgprot_t pgprot = range->pgprot;
+
+       return __vmalloc_node_range(size, align, start, end,
+                                   GFP_KERNEL, pgprot, VM_FLUSH_RESET_PERMS,
+                                   NUMA_NO_NODE, __builtin_return_address(0));
 }
 
 void *execmem_alloc(enum execmem_type type, size_t size)
 {
-       return __execmem_alloc(size);
+       struct execmem_range *range;
+
+       if (!execmem_info)
+               return module_alloc(size);
+
+       range = &execmem_info->ranges[type];
+
+       return __execmem_alloc(range, size);
 }
 
 void execmem_free(void *ptr)
@@ -30,3 +46,48 @@ void execmem_free(void *ptr)
        WARN_ON(in_interrupt());
        vfree(ptr);
 }
+
+static bool execmem_validate(struct execmem_info *info)
+{
+       struct execmem_range *r = &info->ranges[EXECMEM_DEFAULT];
+
+       if (!r->alignment || !r->start || !r->end || !pgprot_val(r->pgprot)) {
+               pr_crit("Invalid parameters for execmem allocator, module loading will fail");
+               return false;
+       }
+
+       return true;
+}
+
+static void execmem_init_missing(struct execmem_info *info)
+{
+       struct execmem_range *default_range = &info->ranges[EXECMEM_DEFAULT];
+
+       for (int i = EXECMEM_DEFAULT + 1; i < EXECMEM_TYPE_MAX; i++) {
+               struct execmem_range *r = &info->ranges[i];
+
+               if (!r->start) {
+                       r->pgprot = default_range->pgprot;
+                       r->alignment = default_range->alignment;
+                       r->start = default_range->start;
+                       r->end = default_range->end;
+               }
+       }
+}
+
+struct execmem_info * __weak execmem_arch_setup(void)
+{
+       return NULL;
+}
+
+void __init execmem_init(void)
+{
+       struct execmem_info *info = execmem_arch_setup();
+
+       if (!info || !execmem_validate(info))
+               return;
+
+       execmem_init_missing(info);
+
+       execmem_info = info;
+}

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 549e76af8f82a8ed2fea2e1439e96f06f7f25b19..b6a1fcf6e13a304331bc0738cc50899c288633ae 100644 (file)
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -27,6 +27,7 @@
 #include <linux/swap.h>
 #include <linux/cma.h>
 #include <linux/crash_dump.h>
+#include <linux/execmem.h>
 #include "internal.h"
 #include "slab.h"
 #include "shuffle.h"
@@ -2793,4 +2794,5 @@ void __init mm_core_init(void)
        pti_init();
        kmsan_init_runtime();
        mm_cache_init();
+       execmem_init();
 }