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