+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * linux/fs/binfmt_aout.c
- *
- * Copyright (C) 1991, 1992, 1996 Linus Torvalds
- */
-
-#include <linux/module.h>
-
-#include <linux/time.h>
-#include <linux/kernel.h>
-#include <linux/mm.h>
-#include <linux/mman.h>
-#include <linux/a.out.h>
-#include <linux/errno.h>
-#include <linux/signal.h>
-#include <linux/string.h>
-#include <linux/fs.h>
-#include <linux/file.h>
-#include <linux/stat.h>
-#include <linux/fcntl.h>
-#include <linux/ptrace.h>
-#include <linux/user.h>
-#include <linux/binfmts.h>
-#include <linux/personality.h>
-#include <linux/init.h>
-#include <linux/coredump.h>
-#include <linux/slab.h>
-#include <linux/sched/task_stack.h>
-
-#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
-
-static int load_aout_binary(struct linux_binprm *);
-static int load_aout_library(struct file*);
-
-static struct linux_binfmt aout_format = {
- .module = THIS_MODULE,
- .load_binary = load_aout_binary,
- .load_shlib = load_aout_library,
-};
-
-#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
-
-static int set_brk(unsigned long start, unsigned long end)
-{
- start = PAGE_ALIGN(start);
- end = PAGE_ALIGN(end);
- if (end > start)
- return vm_brk(start, end - start);
- return 0;
-}
-
-/*
- * create_aout_tables() parses the env- and arg-strings in new user
- * memory and creates the pointer tables from them, and puts their
- * addresses on the "stack", returning the new stack pointer value.
- */
-static unsigned long __user *create_aout_tables(char __user *p, struct linux_binprm * bprm)
-{
- char __user * __user *argv;
- char __user * __user *envp;
- unsigned long __user *sp;
- int argc = bprm->argc;
- int envc = bprm->envc;
-
- sp = (void __user *)((-(unsigned long)sizeof(char *)) & (unsigned long) p);
-#ifdef __alpha__
-/* whee.. test-programs are so much fun. */
- put_user(0, --sp);
- put_user(0, --sp);
- if (bprm->loader) {
- put_user(0, --sp);
- put_user(1003, --sp);
- put_user(bprm->loader, --sp);
- put_user(1002, --sp);
- }
- put_user(bprm->exec, --sp);
- put_user(1001, --sp);
-#endif
- sp -= envc+1;
- envp = (char __user * __user *) sp;
- sp -= argc+1;
- argv = (char __user * __user *) sp;
-#ifndef __alpha__
- put_user((unsigned long) envp,--sp);
- put_user((unsigned long) argv,--sp);
-#endif
- put_user(argc,--sp);
- current->mm->arg_start = (unsigned long) p;
- while (argc-->0) {
- char c;
- put_user(p,argv++);
- do {
- get_user(c,p++);
- } while (c);
- }
- put_user(NULL,argv);
- current->mm->arg_end = current->mm->env_start = (unsigned long) p;
- while (envc-->0) {
- char c;
- put_user(p,envp++);
- do {
- get_user(c,p++);
- } while (c);
- }
- put_user(NULL,envp);
- current->mm->env_end = (unsigned long) p;
- return sp;
-}
-
-/*
- * These are the functions used to load a.out style executables and shared
- * libraries. There is no binary dependent code anywhere else.
- */
-
-static int load_aout_binary(struct linux_binprm * bprm)
-{
- struct pt_regs *regs = current_pt_regs();
- struct exec ex;
- unsigned long error;
- unsigned long fd_offset;
- unsigned long rlim;
- int retval;
-
- ex = *((struct exec *) bprm->buf); /* exec-header */
- if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
- N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) ||
- N_TRSIZE(ex) || N_DRSIZE(ex) ||
- i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
- return -ENOEXEC;
- }
-
- /*
- * Requires a mmap handler. This prevents people from using a.out
- * as part of an exploit attack against /proc-related vulnerabilities.
- */
- if (!bprm->file->f_op->mmap)
- return -ENOEXEC;
-
- fd_offset = N_TXTOFF(ex);
-
- /* Check initial limits. This avoids letting people circumvent
- * size limits imposed on them by creating programs with large
- * arrays in the data or bss.
- */
- rlim = rlimit(RLIMIT_DATA);
- if (rlim >= RLIM_INFINITY)
- rlim = ~0;
- if (ex.a_data + ex.a_bss > rlim)
- return -ENOMEM;
-
- /* Flush all traces of the currently running executable */
- retval = begin_new_exec(bprm);
- if (retval)
- return retval;
-
- /* OK, This is the point of no return */
-#ifdef __alpha__
- SET_AOUT_PERSONALITY(bprm, ex);
-#else
- set_personality(PER_LINUX);
-#endif
- setup_new_exec(bprm);
-
- current->mm->end_code = ex.a_text +
- (current->mm->start_code = N_TXTADDR(ex));
- current->mm->end_data = ex.a_data +
- (current->mm->start_data = N_DATADDR(ex));
- current->mm->brk = ex.a_bss +
- (current->mm->start_brk = N_BSSADDR(ex));
-
- retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
- if (retval < 0)
- return retval;
-
-
- if (N_MAGIC(ex) == OMAGIC) {
- unsigned long text_addr, map_size;
- loff_t pos;
-
- text_addr = N_TXTADDR(ex);
-
-#ifdef __alpha__
- pos = fd_offset;
- map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
-#else
- pos = 32;
- map_size = ex.a_text+ex.a_data;
-#endif
- error = vm_brk(text_addr & PAGE_MASK, map_size);
- if (error)
- return error;
-
- error = read_code(bprm->file, text_addr, pos,
- ex.a_text+ex.a_data);
- if ((signed long)error < 0)
- return error;
- } else {
- if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
- (N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
- {
- printk(KERN_NOTICE "executable not page aligned\n");
- }
-
- if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
- {
- printk(KERN_WARNING
- "fd_offset is not page aligned. Please convert program: %pD\n",
- bprm->file);
- }
-
- if (!bprm->file->f_op->mmap||((fd_offset & ~PAGE_MASK) != 0)) {
- error = vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
- if (error)
- return error;
-
- read_code(bprm->file, N_TXTADDR(ex), fd_offset,
- ex.a_text + ex.a_data);
- goto beyond_if;
- }
-
- error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
- PROT_READ | PROT_EXEC, MAP_FIXED | MAP_PRIVATE,
- fd_offset);
-
- if (error != N_TXTADDR(ex))
- return error;
-
- error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
- PROT_READ | PROT_WRITE | PROT_EXEC,
- MAP_FIXED | MAP_PRIVATE,
- fd_offset + ex.a_text);
- if (error != N_DATADDR(ex))
- return error;
- }
-beyond_if:
- set_binfmt(&aout_format);
-
- retval = set_brk(current->mm->start_brk, current->mm->brk);
- if (retval < 0)
- return retval;
-
- current->mm->start_stack =
- (unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
-#ifdef __alpha__
- regs->gp = ex.a_gpvalue;
-#endif
- finalize_exec(bprm);
- start_thread(regs, ex.a_entry, current->mm->start_stack);
- return 0;
-}
-
-static int load_aout_library(struct file *file)
-{
- struct inode * inode;
- unsigned long bss, start_addr, len;
- unsigned long error;
- int retval;
- struct exec ex;
- loff_t pos = 0;
-
- inode = file_inode(file);
-
- retval = -ENOEXEC;
- error = kernel_read(file, &ex, sizeof(ex), &pos);
- if (error != sizeof(ex))
- goto out;
-
- /* We come in here for the regular a.out style of shared libraries */
- if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) || N_TRSIZE(ex) ||
- N_DRSIZE(ex) || ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) ||
- i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
- goto out;
- }
-
- /*
- * Requires a mmap handler. This prevents people from using a.out
- * as part of an exploit attack against /proc-related vulnerabilities.
- */
- if (!file->f_op->mmap)
- goto out;
-
- if (N_FLAGS(ex))
- goto out;
-
- /* For QMAGIC, the starting address is 0x20 into the page. We mask
- this off to get the starting address for the page */
-
- start_addr = ex.a_entry & 0xfffff000;
-
- if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
- if (printk_ratelimit())
- {
- printk(KERN_WARNING
- "N_TXTOFF is not page aligned. Please convert library: %pD\n",
- file);
- }
- retval = vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
- if (retval)
- goto out;
-
- read_code(file, start_addr, N_TXTOFF(ex),
- ex.a_text + ex.a_data);
- retval = 0;
- goto out;
- }
- /* Now use mmap to map the library into memory. */
- error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
- PROT_READ | PROT_WRITE | PROT_EXEC,
- MAP_FIXED | MAP_PRIVATE,
- N_TXTOFF(ex));
- retval = error;
- if (error != start_addr)
- goto out;
-
- len = PAGE_ALIGN(ex.a_text + ex.a_data);
- bss = ex.a_text + ex.a_data + ex.a_bss;
- if (bss > len) {
- retval = vm_brk(start_addr + len, bss - len);
- if (retval)
- goto out;
- }
- retval = 0;
-out:
- return retval;
-}
-
-static int __init init_aout_binfmt(void)
-{
- register_binfmt(&aout_format);
- return 0;
-}
-
-static void __exit exit_aout_binfmt(void)
-{
- unregister_binfmt(&aout_format);
-}
-
-core_initcall(init_aout_binfmt);
-module_exit(exit_aout_binfmt);
-MODULE_LICENSE("GPL");
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