424 lines
11 KiB
C
424 lines
11 KiB
C
/*
|
|
* 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 <asm/uaccess.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/a.out-core.h>
|
|
|
|
static int load_aout_binary(struct linux_binprm *);
|
|
static int load_aout_library(struct file*);
|
|
|
|
#ifdef CONFIG_COREDUMP
|
|
/*
|
|
* Routine writes a core dump image in the current directory.
|
|
* Currently only a stub-function.
|
|
*
|
|
* Note that setuid/setgid files won't make a core-dump if the uid/gid
|
|
* changed due to the set[u|g]id. It's enforced by the "current->mm->dumpable"
|
|
* field, which also makes sure the core-dumps won't be recursive if the
|
|
* dumping of the process results in another error..
|
|
*/
|
|
static int aout_core_dump(struct coredump_params *cprm)
|
|
{
|
|
mm_segment_t fs;
|
|
int has_dumped = 0;
|
|
void __user *dump_start;
|
|
int dump_size;
|
|
struct user dump;
|
|
#ifdef __alpha__
|
|
# define START_DATA(u) ((void __user *)u.start_data)
|
|
#else
|
|
# define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \
|
|
u.start_code))
|
|
#endif
|
|
# define START_STACK(u) ((void __user *)u.start_stack)
|
|
|
|
fs = get_fs();
|
|
set_fs(KERNEL_DS);
|
|
has_dumped = 1;
|
|
strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
|
|
dump.u_ar0 = offsetof(struct user, regs);
|
|
dump.signal = cprm->siginfo->si_signo;
|
|
aout_dump_thread(cprm->regs, &dump);
|
|
|
|
/* If the size of the dump file exceeds the rlimit, then see what would happen
|
|
if we wrote the stack, but not the data area. */
|
|
if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
|
|
dump.u_dsize = 0;
|
|
|
|
/* Make sure we have enough room to write the stack and data areas. */
|
|
if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
|
|
dump.u_ssize = 0;
|
|
|
|
/* make sure we actually have a data and stack area to dump */
|
|
set_fs(USER_DS);
|
|
if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
|
|
dump.u_dsize = 0;
|
|
if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
|
|
dump.u_ssize = 0;
|
|
|
|
set_fs(KERNEL_DS);
|
|
/* struct user */
|
|
if (!dump_emit(cprm, &dump, sizeof(dump)))
|
|
goto end_coredump;
|
|
/* Now dump all of the user data. Include malloced stuff as well */
|
|
if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
|
|
goto end_coredump;
|
|
/* now we start writing out the user space info */
|
|
set_fs(USER_DS);
|
|
/* Dump the data area */
|
|
if (dump.u_dsize != 0) {
|
|
dump_start = START_DATA(dump);
|
|
dump_size = dump.u_dsize << PAGE_SHIFT;
|
|
if (!dump_emit(cprm, dump_start, dump_size))
|
|
goto end_coredump;
|
|
}
|
|
/* Now prepare to dump the stack area */
|
|
if (dump.u_ssize != 0) {
|
|
dump_start = START_STACK(dump);
|
|
dump_size = dump.u_ssize << PAGE_SHIFT;
|
|
if (!dump_emit(cprm, dump_start, dump_size))
|
|
goto end_coredump;
|
|
}
|
|
end_coredump:
|
|
set_fs(fs);
|
|
return has_dumped;
|
|
}
|
|
#else
|
|
#define aout_core_dump NULL
|
|
#endif
|
|
|
|
static struct linux_binfmt aout_format = {
|
|
.module = THIS_MODULE,
|
|
.load_binary = load_aout_binary,
|
|
.load_shlib = load_aout_library,
|
|
.core_dump = aout_core_dump,
|
|
.min_coredump = PAGE_SIZE
|
|
};
|
|
|
|
#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) {
|
|
unsigned long addr;
|
|
addr = vm_brk(start, end - start);
|
|
if (BAD_ADDR(addr))
|
|
return addr;
|
|
}
|
|
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 = flush_old_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;
|
|
|
|
install_exec_creds(bprm);
|
|
|
|
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 != (text_addr & PAGE_MASK))
|
|
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)) {
|
|
vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
|
|
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,
|
|
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,
|
|
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
|
|
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;
|
|
|
|
inode = file_inode(file);
|
|
|
|
retval = -ENOEXEC;
|
|
error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
|
|
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);
|
|
}
|
|
vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
|
|
|
|
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,
|
|
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) {
|
|
error = vm_brk(start_addr + len, bss - len);
|
|
retval = error;
|
|
if (error != start_addr + len)
|
|
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");
|