[linux.git] / fs / binfmt_aout.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) {
		/* Someone check-me: is this error path enough? */
		send_sig(SIGKILL, current, 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)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}

		error = read_code(bprm->file, text_addr, pos,
				  ex.a_text+ex.a_data);
		if ((signed long)error < 0) {
			send_sig(SIGKILL, current, 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: %s\n",
			       bprm->file->f_path.dentry->d_name.name);
		}

		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)) {
			send_sig(SIGKILL, current, 0);
			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)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}
	}
beyond_if:
	set_binfmt(&aout_format);

	retval = set_brk(current->mm->start_brk, current->mm->brk);
	if (retval < 0) {
		send_sig(SIGKILL, current, 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: %s\n",
			       file->f_path.dentry->d_name.name);
		}
		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");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/binfmt_aout.c
	3	*
	4	* Copyright (C) 1991, 1992, 1996 Linus Torvalds
	5	*/
	6
	7	#include <linux/module.h>
	8
	9	#include <linux/time.h>
	10	#include <linux/kernel.h>
	11	#include <linux/mm.h>
	12	#include <linux/mman.h>
	13	#include <linux/a.out.h>
	14	#include <linux/errno.h>
	15	#include <linux/signal.h>
	16	#include <linux/string.h>
	17	#include <linux/fs.h>
	18	#include <linux/file.h>
	19	#include <linux/stat.h>
	20	#include <linux/fcntl.h>
	21	#include <linux/ptrace.h>
	22	#include <linux/user.h>
1da177e4 LT	23	#include <linux/binfmts.h>
	24	#include <linux/personality.h>
	25	#include <linux/init.h>
088e7af7	26	#include <linux/coredump.h>
5a0e3ad6	27	#include <linux/slab.h>
1da177e4	28
1da177e4 LT	29	#include <asm/uaccess.h>
1da177e4 LT	30	#include <asm/cacheflush.h>
7fa30315	31	#include <asm/a.out-core.h>
1da177e4	32
71613c3b	33	static int load_aout_binary(struct linux_binprm *);
1da177e4	34	static int load_aout_library(struct file*);
1da177e4	35
046d662f	36	#ifdef CONFIG_COREDUMP
1da177e4 LT	37	/*
	38	* Routine writes a core dump image in the current directory.
	39	* Currently only a stub-function.
	40	*
	41	* Note that setuid/setgid files won't make a core-dump if the uid/gid
	42	* changed due to the set[u\|g]id. It's enforced by the "current->mm->dumpable"
	43	* field, which also makes sure the core-dumps won't be recursive if the
	44	* dumping of the process results in another error..
	45	*/
f6151dfe	46	static int aout_core_dump(struct coredump_params *cprm)
1da177e4 LT	47	{
	48	mm_segment_t fs;
	49	int has_dumped = 0;
7731d9a5 BP	50	void __user *dump_start;
7731d9a5 BP	51	int dump_size;
1da177e4	52	struct user dump;
17580d7f	53	#ifdef __alpha__
7731d9a5	54	# define START_DATA(u) ((void __user *)u.start_data)
17580d7f	55	#else
7731d9a5 BP	56	# define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \
7731d9a5 BP	57	u.start_code))
1da177e4	58	#endif
7731d9a5	59	# define START_STACK(u) ((void __user *)u.start_stack)
1da177e4 LT	60
	61	fs = get_fs();
	62	set_fs(KERNEL_DS);
	63	has_dumped = 1;
1da177e4	64	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
6e16d89b	65	dump.u_ar0 = offsetof(struct user, regs);
5ab1c309	66	dump.signal = cprm->siginfo->si_signo;
f6151dfe	67	aout_dump_thread(cprm->regs, &dump);
1da177e4 LT	68
	69	/* If the size of the dump file exceeds the rlimit, then see what would happen
	70	if we wrote the stack, but not the data area. */
f6151dfe	71	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
1da177e4	72	dump.u_dsize = 0;
1da177e4 LT	73
1da177e4 LT	74	/* Make sure we have enough room to write the stack and data areas. */
f6151dfe	75	if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
1da177e4	76	dump.u_ssize = 0;
1da177e4 LT	77
	78	/* make sure we actually have a data and stack area to dump */
	79	set_fs(USER_DS);
7731d9a5	80	if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
1da177e4	81	dump.u_dsize = 0;
7731d9a5	82	if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
1da177e4	83	dump.u_ssize = 0;
1da177e4 LT	84
	85	set_fs(KERNEL_DS);
	86	/* struct user */
43a5d548	87	if (!dump_emit(cprm, &dump, sizeof(dump)))
088e7af7	88	goto end_coredump;
1da177e4	89	/* Now dump all of the user data. Include malloced stuff as well */
9b56d543	90	if (!dump_skip(cprm, PAGE_SIZE - sizeof(dump)))
05f47fda	91	goto end_coredump;
1da177e4 LT	92	/* now we start writing out the user space info */
	93	set_fs(USER_DS);
	94	/* Dump the data area */
	95	if (dump.u_dsize != 0) {
	96	dump_start = START_DATA(dump);
1da177e4	97	dump_size = dump.u_dsize << PAGE_SHIFT;
43a5d548	98	if (!dump_emit(cprm, dump_start, dump_size))
088e7af7	99	goto end_coredump;
1da177e4 LT	100	}
	101	/* Now prepare to dump the stack area */
	102	if (dump.u_ssize != 0) {
	103	dump_start = START_STACK(dump);
1da177e4	104	dump_size = dump.u_ssize << PAGE_SHIFT;
43a5d548	105	if (!dump_emit(cprm, dump_start, dump_size))
088e7af7	106	goto end_coredump;
1da177e4	107	}
1da177e4 LT	108	end_coredump:
	109	set_fs(fs);
	110	return has_dumped;
	111	}
046d662f AK	112	#else
	113	#define aout_core_dump NULL
	114	#endif
	115
	116	static struct linux_binfmt aout_format = {
	117	.module = THIS_MODULE,
	118	.load_binary = load_aout_binary,
	119	.load_shlib = load_aout_library,
	120	.core_dump = aout_core_dump,
	121	.min_coredump = PAGE_SIZE
	122	};
	123
	124	#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
	125
	126	static int set_brk(unsigned long start, unsigned long end)
	127	{
	128	start = PAGE_ALIGN(start);
	129	end = PAGE_ALIGN(end);
	130	if (end > start) {
	131	unsigned long addr;
	132	addr = vm_brk(start, end - start);
	133	if (BAD_ADDR(addr))
	134	return addr;
	135	}
	136	return 0;
	137	}
1da177e4 LT	138
	139	/*
	140	* create_aout_tables() parses the env- and arg-strings in new user
	141	* memory and creates the pointer tables from them, and puts their
	142	* addresses on the "stack", returning the new stack pointer value.
	143	*/
	144	static unsigned long __user create_aout_tables(char __user p, struct linux_binprm * bprm)
	145	{
	146	char __user * __user *argv;
	147	char __user * __user *envp;
	148	unsigned long __user *sp;
	149	int argc = bprm->argc;
	150	int envc = bprm->envc;
	151
	152	sp = (void __user )((-(unsigned long)sizeof(char )) & (unsigned long) p);
1da177e4 LT	153	#ifdef __alpha__
	154	/* whee.. test-programs are so much fun. */
	155	put_user(0, --sp);
	156	put_user(0, --sp);
	157	if (bprm->loader) {
	158	put_user(0, --sp);
17580d7f	159	put_user(1003, --sp);
1da177e4	160	put_user(bprm->loader, --sp);
17580d7f	161	put_user(1002, --sp);
1da177e4 LT	162	}
1da177e4 LT	163	put_user(bprm->exec, --sp);
17580d7f	164	put_user(1001, --sp);
1da177e4 LT	165	#endif
	166	sp -= envc+1;
	167	envp = (char __user * __user *) sp;
	168	sp -= argc+1;
	169	argv = (char __user * __user *) sp;
17580d7f	170	#ifndef __alpha__
1da177e4 LT	171	put_user((unsigned long) envp,--sp);
	172	put_user((unsigned long) argv,--sp);
	173	#endif
	174	put_user(argc,--sp);
	175	current->mm->arg_start = (unsigned long) p;
	176	while (argc-->0) {
	177	char c;
	178	put_user(p,argv++);
	179	do {
	180	get_user(c,p++);
	181	} while (c);
	182	}
	183	put_user(NULL,argv);
	184	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	185	while (envc-->0) {
	186	char c;
	187	put_user(p,envp++);
	188	do {
	189	get_user(c,p++);
	190	} while (c);
	191	}
	192	put_user(NULL,envp);
	193	current->mm->env_end = (unsigned long) p;
	194	return sp;
	195	}
	196
	197	/*
	198	* These are the functions used to load a.out style executables and shared
	199	* libraries. There is no binary dependent code anywhere else.
	200	*/
	201
71613c3b	202	static int load_aout_binary(struct linux_binprm * bprm)
1da177e4	203	{
71613c3b	204	struct pt_regs *regs = current_pt_regs();
1da177e4 LT	205	struct exec ex;
	206	unsigned long error;
	207	unsigned long fd_offset;
	208	unsigned long rlim;
	209	int retval;
	210
	211	ex = ((struct exec ) bprm->buf); /* exec-header */
	212	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
	213	N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) \|\|
	214	N_TRSIZE(ex) \|\| N_DRSIZE(ex) \|\|
496ad9aa	215	i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
1da177e4 LT	216	return -ENOEXEC;
	217	}
	218
8454aeef ET	219	/*
	220	* Requires a mmap handler. This prevents people from using a.out
	221	* as part of an exploit attack against /proc-related vulnerabilities.
	222	*/
72c2d531	223	if (!bprm->file->f_op->mmap)
8454aeef ET	224	return -ENOEXEC;
8454aeef ET	225
1da177e4 LT	226	fd_offset = N_TXTOFF(ex);
	227
	228	/* Check initial limits. This avoids letting people circumvent
	229	* size limits imposed on them by creating programs with large
	230	* arrays in the data or bss.
	231	*/
d554ed89	232	rlim = rlimit(RLIMIT_DATA);
1da177e4 LT	233	if (rlim >= RLIM_INFINITY)
	234	rlim = ~0;
	235	if (ex.a_data + ex.a_bss > rlim)
	236	return -ENOMEM;
	237
	238	/* Flush all traces of the currently running executable */
	239	retval = flush_old_exec(bprm);
	240	if (retval)
	241	return retval;
	242
	243	/* OK, This is the point of no return */
17580d7f	244	#ifdef __alpha__
1da177e4	245	SET_AOUT_PERSONALITY(bprm, ex);
1da177e4 LT	246	#else
	247	set_personality(PER_LINUX);
	248	#endif
221af7f8	249	setup_new_exec(bprm);
1da177e4 LT	250
	251	current->mm->end_code = ex.a_text +
	252	(current->mm->start_code = N_TXTADDR(ex));
	253	current->mm->end_data = ex.a_data +
	254	(current->mm->start_data = N_DATADDR(ex));
	255	current->mm->brk = ex.a_bss +
	256	(current->mm->start_brk = N_BSSADDR(ex));
1da177e4	257
6414fa6a AV	258	retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
	259	if (retval < 0) {
	260	/* Someone check-me: is this error path enough? */
	261	send_sig(SIGKILL, current, 0);
	262	return retval;
	263	}
	264
a6f76f23	265	install_exec_creds(bprm);
1da177e4 LT	266
	267	if (N_MAGIC(ex) == OMAGIC) {
	268	unsigned long text_addr, map_size;
	269	loff_t pos;
	270
	271	text_addr = N_TXTADDR(ex);
	272
fe30af97	273	#ifdef __alpha__
1da177e4 LT	274	pos = fd_offset;
	275	map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
	276	#else
	277	pos = 32;
	278	map_size = ex.a_text+ex.a_data;
	279	#endif
e4eb1ff6	280	error = vm_brk(text_addr & PAGE_MASK, map_size);
1da177e4 LT	281	if (error != (text_addr & PAGE_MASK)) {
	282	send_sig(SIGKILL, current, 0);
	283	return error;
	284	}
	285
3dc20cb2 AV	286	error = read_code(bprm->file, text_addr, pos,
3dc20cb2 AV	287	ex.a_text+ex.a_data);
1da177e4 LT	288	if ((signed long)error < 0) {
	289	send_sig(SIGKILL, current, 0);
	290	return error;
	291	}
1da177e4	292	} else {
1da177e4	293	if ((ex.a_text & 0xfff \|\| ex.a_data & 0xfff) &&
2e50b6cc	294	(N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
1da177e4 LT	295	{
1da177e4 LT	296	printk(KERN_NOTICE "executable not page aligned\n");
1da177e4 LT	297	}
1da177e4 LT	298
2e50b6cc	299	if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
1da177e4 LT	300	{
	301	printk(KERN_WARNING
	302	"fd_offset is not page aligned. Please convert program: %s\n",
0f7fc9e4	303	bprm->file->f_path.dentry->d_name.name);
1da177e4 LT	304	}
	305
	306	if (!bprm->file->f_op->mmap\|\|((fd_offset & ~PAGE_MASK) != 0)) {
e4eb1ff6	307	vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
3dc20cb2 AV	308	read_code(bprm->file, N_TXTADDR(ex), fd_offset,
3dc20cb2 AV	309	ex.a_text + ex.a_data);
1da177e4 LT	310	goto beyond_if;
	311	}
	312
6be5ceb0	313	error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
1da177e4 LT	314	PROT_READ \| PROT_EXEC,
	315	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	316	fd_offset);
1da177e4 LT	317
	318	if (error != N_TXTADDR(ex)) {
	319	send_sig(SIGKILL, current, 0);
	320	return error;
	321	}
	322
6be5ceb0	323	error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
1da177e4 LT	324	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	325	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	326	fd_offset + ex.a_text);
1da177e4 LT	327	if (error != N_DATADDR(ex)) {
	328	send_sig(SIGKILL, current, 0);
	329	return error;
	330	}
	331	}
	332	beyond_if:
	333	set_binfmt(&aout_format);
	334
	335	retval = set_brk(current->mm->start_brk, current->mm->brk);
	336	if (retval < 0) {
	337	send_sig(SIGKILL, current, 0);
	338	return retval;
	339	}
	340
1da177e4 LT	341	current->mm->start_stack =
	342	(unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
	343	#ifdef __alpha__
	344	regs->gp = ex.a_gpvalue;
	345	#endif
	346	start_thread(regs, ex.a_entry, current->mm->start_stack);
1da177e4 LT	347	return 0;
	348	}
	349
	350	static int load_aout_library(struct file *file)
	351	{
	352	struct inode * inode;
	353	unsigned long bss, start_addr, len;
	354	unsigned long error;
	355	int retval;
	356	struct exec ex;
	357
496ad9aa	358	inode = file_inode(file);
1da177e4 LT	359
	360	retval = -ENOEXEC;
	361	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
	362	if (error != sizeof(ex))
	363	goto out;
	364
	365	/* We come in here for the regular a.out style of shared libraries */
	366	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) \|\| N_TRSIZE(ex) \|\|
	367	N_DRSIZE(ex) \|\| ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) \|\|
	368	i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
	369	goto out;
	370	}
	371
8454aeef ET	372	/*
	373	* Requires a mmap handler. This prevents people from using a.out
	374	* as part of an exploit attack against /proc-related vulnerabilities.
	375	*/
72c2d531	376	if (!file->f_op->mmap)
8454aeef ET	377	goto out;
8454aeef ET	378
1da177e4 LT	379	if (N_FLAGS(ex))
	380	goto out;
	381
	382	/* For QMAGIC, the starting address is 0x20 into the page. We mask
	383	this off to get the starting address for the page */
	384
	385	start_addr = ex.a_entry & 0xfffff000;
	386
	387	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
2e50b6cc	388	if (printk_ratelimit())
1da177e4 LT	389	{
	390	printk(KERN_WARNING
	391	"N_TXTOFF is not page aligned. Please convert library: %s\n",
0f7fc9e4	392	file->f_path.dentry->d_name.name);
1da177e4	393	}
e4eb1ff6	394	vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
1da177e4	395
3dc20cb2 AV	396	read_code(file, start_addr, N_TXTOFF(ex),
3dc20cb2 AV	397	ex.a_text + ex.a_data);
1da177e4 LT	398	retval = 0;
	399	goto out;
	400	}
	401	/* Now use mmap to map the library into memory. */
6be5ceb0	402	error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
1da177e4 LT	403	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	404	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE,
	405	N_TXTOFF(ex));
1da177e4 LT	406	retval = error;
	407	if (error != start_addr)
	408	goto out;
	409
	410	len = PAGE_ALIGN(ex.a_text + ex.a_data);
	411	bss = ex.a_text + ex.a_data + ex.a_bss;
	412	if (bss > len) {
e4eb1ff6	413	error = vm_brk(start_addr + len, bss - len);
1da177e4 LT	414	retval = error;
	415	if (error != start_addr + len)
	416	goto out;
	417	}
	418	retval = 0;
	419	out:
	420	return retval;
	421	}
	422
	423	static int __init init_aout_binfmt(void)
	424	{
8fc3dc5a AV	425	register_binfmt(&aout_format);
8fc3dc5a AV	426	return 0;
1da177e4 LT	427	}
	428
	429	static void __exit exit_aout_binfmt(void)
	430	{
	431	unregister_binfmt(&aout_format);
	432	}
	433
	434	core_initcall(init_aout_binfmt);
	435	module_exit(exit_aout_binfmt);
	436	MODULE_LICENSE("GPL");