332 lines
8.1 KiB
C
332 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* a.out loader for x86-64
|
|
*
|
|
* Copyright (C) 1991, 1992, 1996 Linus Torvalds
|
|
* Hacked together by Andi Kleen
|
|
*/
|
|
|
|
#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/jiffies.h>
|
|
#include <linux/perf_event.h>
|
|
#include <linux/sched/task_stack.h>
|
|
|
|
#include <linux/uaccess.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/user32.h>
|
|
#include <asm/ia32.h>
|
|
|
|
#undef WARN_OLD
|
|
|
|
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,
|
|
};
|
|
|
|
static int set_brk(unsigned long start, unsigned long end)
|
|
{
|
|
start = PAGE_ALIGN(start);
|
|
end = PAGE_ALIGN(end);
|
|
if (end <= start)
|
|
return 0;
|
|
return vm_brk(start, end - start);
|
|
}
|
|
|
|
|
|
/*
|
|
* 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 u32 __user *create_aout_tables(char __user *p, struct linux_binprm *bprm)
|
|
{
|
|
u32 __user *argv, *envp, *sp;
|
|
int argc = bprm->argc, envc = bprm->envc;
|
|
|
|
sp = (u32 __user *) ((-(unsigned long)sizeof(u32)) & (unsigned long) p);
|
|
sp -= envc+1;
|
|
envp = sp;
|
|
sp -= argc+1;
|
|
argv = sp;
|
|
put_user((unsigned long) envp, --sp);
|
|
put_user((unsigned long) argv, --sp);
|
|
put_user(argc, --sp);
|
|
current->mm->arg_start = (unsigned long) p;
|
|
while (argc-- > 0) {
|
|
char c;
|
|
|
|
put_user((u32)(unsigned long)p, argv++);
|
|
do {
|
|
get_user(c, p++);
|
|
} while (c);
|
|
}
|
|
put_user(0, argv);
|
|
current->mm->arg_end = current->mm->env_start = (unsigned long) p;
|
|
while (envc-- > 0) {
|
|
char c;
|
|
|
|
put_user((u32)(unsigned long)p, envp++);
|
|
do {
|
|
get_user(c, p++);
|
|
} while (c);
|
|
}
|
|
put_user(0, 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)
|
|
{
|
|
unsigned long error, fd_offset, rlim;
|
|
struct pt_regs *regs = current_pt_regs();
|
|
struct exec ex;
|
|
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;
|
|
}
|
|
|
|
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 = flush_old_exec(bprm);
|
|
if (retval)
|
|
return retval;
|
|
|
|
/* OK, This is the point of no return */
|
|
set_personality(PER_LINUX);
|
|
set_personality_ia32(false);
|
|
|
|
setup_new_exec(bprm);
|
|
|
|
regs->cs = __USER32_CS;
|
|
regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
|
|
regs->r13 = regs->r14 = regs->r15 = 0;
|
|
|
|
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, IA32_STACK_TOP, EXSTACK_DEFAULT);
|
|
if (retval < 0)
|
|
return retval;
|
|
|
|
install_exec_creds(bprm);
|
|
|
|
if (N_MAGIC(ex) == OMAGIC) {
|
|
unsigned long text_addr, map_size;
|
|
|
|
text_addr = N_TXTADDR(ex);
|
|
map_size = ex.a_text+ex.a_data;
|
|
|
|
error = vm_brk(text_addr & PAGE_MASK, map_size);
|
|
|
|
if (error)
|
|
return error;
|
|
|
|
error = read_code(bprm->file, text_addr, 32,
|
|
ex.a_text + ex.a_data);
|
|
if ((signed long)error < 0)
|
|
return error;
|
|
} else {
|
|
#ifdef WARN_OLD
|
|
static unsigned long error_time, error_time2;
|
|
if ((ex.a_text & 0xfff || ex.a_data & 0xfff) &&
|
|
(N_MAGIC(ex) != NMAGIC) &&
|
|
time_after(jiffies, error_time2 + 5*HZ)) {
|
|
printk(KERN_NOTICE "executable not page aligned\n");
|
|
error_time2 = jiffies;
|
|
}
|
|
|
|
if ((fd_offset & ~PAGE_MASK) != 0 &&
|
|
time_after(jiffies, error_time + 5*HZ)) {
|
|
printk(KERN_WARNING
|
|
"fd_offset is not page aligned. Please convert "
|
|
"program: %pD\n",
|
|
bprm->file);
|
|
error_time = jiffies;
|
|
}
|
|
#endif
|
|
|
|
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 | MAP_DENYWRITE |
|
|
MAP_EXECUTABLE | MAP_32BIT,
|
|
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 | MAP_DENYWRITE |
|
|
MAP_EXECUTABLE | MAP_32BIT,
|
|
fd_offset + ex.a_text);
|
|
if (error != N_DATADDR(ex))
|
|
return error;
|
|
}
|
|
|
|
beyond_if:
|
|
error = set_brk(current->mm->start_brk, current->mm->brk);
|
|
if (error)
|
|
return error;
|
|
|
|
set_binfmt(&aout_format);
|
|
|
|
current->mm->start_stack =
|
|
(unsigned long)create_aout_tables((char __user *)bprm->p, bprm);
|
|
/* start thread */
|
|
loadsegment(fs, 0);
|
|
loadsegment(ds, __USER32_DS);
|
|
loadsegment(es, __USER32_DS);
|
|
load_gs_index(0);
|
|
(regs)->ip = ex.a_entry;
|
|
(regs)->sp = current->mm->start_stack;
|
|
(regs)->flags = 0x200;
|
|
(regs)->cs = __USER32_CS;
|
|
(regs)->ss = __USER32_DS;
|
|
regs->r8 = regs->r9 = regs->r10 = regs->r11 =
|
|
regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
|
|
set_fs(USER_DS);
|
|
return 0;
|
|
}
|
|
|
|
static int load_aout_library(struct file *file)
|
|
{
|
|
unsigned long bss, start_addr, len, error;
|
|
int retval;
|
|
struct exec ex;
|
|
loff_t pos = 0;
|
|
|
|
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(file_inode(file)) <
|
|
ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
|
|
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) {
|
|
#ifdef WARN_OLD
|
|
static unsigned long error_time;
|
|
if (time_after(jiffies, error_time + 5*HZ)) {
|
|
printk(KERN_WARNING
|
|
"N_TXTOFF is not page aligned. Please convert "
|
|
"library: %pD\n",
|
|
file);
|
|
error_time = jiffies;
|
|
}
|
|
#endif
|
|
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 | MAP_DENYWRITE | MAP_32BIT,
|
|
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);
|
|
}
|
|
|
|
module_init(init_aout_binfmt);
|
|
module_exit(exit_aout_binfmt);
|
|
MODULE_LICENSE("GPL");
|