[deliverable/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)
{
	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;
	current->flags |= PF_DUMPCORE;
       	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));
	current->mm->free_area_cache = current->mm->mmap_base;
	current->mm->cached_hole_size = 0;

	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 = bprm->file->f_op->read(bprm->file,
			  (char __user *)text_addr,
			  ex.a_text+ex.a_data, &pos);
		if ((signed long)error < 0) {
			send_sig(SIGKILL, current, 0);
			return error;
		}
			 
		flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
	} 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)) {
			loff_t pos = fd_offset;
			vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
			bprm->file->f_op->read(bprm->file,
					(char __user *)N_TXTADDR(ex),
					ex.a_text+ex.a_data, &pos);
			flush_icache_range((unsigned long) N_TXTADDR(ex),
					   (unsigned long) N_TXTADDR(ex) +
					   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) {
		loff_t pos = N_TXTOFF(ex);

		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);
		
		file->f_op->read(file, (char __user *)start_addr,
			ex.a_text + ex.a_data, &pos);
		flush_icache_range((unsigned long) start_addr,
				   (unsigned long) start_addr + 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;
	65	current->flags \|= PF_DUMPCORE;
	66	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
6e16d89b	67	dump.u_ar0 = offsetof(struct user, regs);
5ab1c309	68	dump.signal = cprm->siginfo->si_signo;
f6151dfe	69	aout_dump_thread(cprm->regs, &dump);
1da177e4 LT	70
	71	/* If the size of the dump file exceeds the rlimit, then see what would happen
	72	if we wrote the stack, but not the data area. */
f6151dfe	73	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
1da177e4	74	dump.u_dsize = 0;
1da177e4 LT	75
1da177e4 LT	76	/* Make sure we have enough room to write the stack and data areas. */
f6151dfe	77	if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
1da177e4	78	dump.u_ssize = 0;
1da177e4 LT	79
	80	/* make sure we actually have a data and stack area to dump */
	81	set_fs(USER_DS);
7731d9a5	82	if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
1da177e4	83	dump.u_dsize = 0;
7731d9a5	84	if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
1da177e4	85	dump.u_ssize = 0;
1da177e4 LT	86
	87	set_fs(KERNEL_DS);
	88	/* struct user */
088e7af7 DH	89	if (!dump_write(file, &dump, sizeof(dump)))
088e7af7 DH	90	goto end_coredump;
1da177e4	91	/* Now dump all of the user data. Include malloced stuff as well */
05f47fda DH	92	if (!dump_seek(cprm->file, PAGE_SIZE - sizeof(dump)))
05f47fda DH	93	goto end_coredump;
1da177e4 LT	94	/* now we start writing out the user space info */
	95	set_fs(USER_DS);
	96	/* Dump the data area */
	97	if (dump.u_dsize != 0) {
	98	dump_start = START_DATA(dump);
1da177e4	99	dump_size = dump.u_dsize << PAGE_SHIFT;
088e7af7 DH	100	if (!dump_write(file, dump_start, dump_size))
088e7af7 DH	101	goto end_coredump;
1da177e4 LT	102	}
	103	/* Now prepare to dump the stack area */
	104	if (dump.u_ssize != 0) {
	105	dump_start = START_STACK(dump);
1da177e4	106	dump_size = dump.u_ssize << PAGE_SHIFT;
088e7af7 DH	107	if (!dump_write(file, dump_start, dump_size))
088e7af7 DH	108	goto end_coredump;
1da177e4	109	}
1da177e4 LT	110	end_coredump:
	111	set_fs(fs);
	112	return has_dumped;
	113	}
046d662f AK	114	#else
	115	#define aout_core_dump NULL
	116	#endif
	117
	118	static struct linux_binfmt aout_format = {
	119	.module = THIS_MODULE,
	120	.load_binary = load_aout_binary,
	121	.load_shlib = load_aout_library,
	122	.core_dump = aout_core_dump,
	123	.min_coredump = PAGE_SIZE
	124	};
	125
	126	#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
	127
	128	static int set_brk(unsigned long start, unsigned long end)
	129	{
	130	start = PAGE_ALIGN(start);
	131	end = PAGE_ALIGN(end);
	132	if (end > start) {
	133	unsigned long addr;
	134	addr = vm_brk(start, end - start);
	135	if (BAD_ADDR(addr))
	136	return addr;
	137	}
	138	return 0;
	139	}
1da177e4 LT	140
	141	/*
	142	* create_aout_tables() parses the env- and arg-strings in new user
	143	* memory and creates the pointer tables from them, and puts their
	144	* addresses on the "stack", returning the new stack pointer value.
	145	*/
	146	static unsigned long __user create_aout_tables(char __user p, struct linux_binprm * bprm)
	147	{
	148	char __user * __user *argv;
	149	char __user * __user *envp;
	150	unsigned long __user *sp;
	151	int argc = bprm->argc;
	152	int envc = bprm->envc;
	153
	154	sp = (void __user )((-(unsigned long)sizeof(char )) & (unsigned long) p);
1da177e4 LT	155	#ifdef __alpha__
	156	/* whee.. test-programs are so much fun. */
	157	put_user(0, --sp);
	158	put_user(0, --sp);
	159	if (bprm->loader) {
	160	put_user(0, --sp);
17580d7f	161	put_user(1003, --sp);
1da177e4	162	put_user(bprm->loader, --sp);
17580d7f	163	put_user(1002, --sp);
1da177e4 LT	164	}
1da177e4 LT	165	put_user(bprm->exec, --sp);
17580d7f	166	put_user(1001, --sp);
1da177e4 LT	167	#endif
	168	sp -= envc+1;
	169	envp = (char __user * __user *) sp;
	170	sp -= argc+1;
	171	argv = (char __user * __user *) sp;
17580d7f	172	#ifndef __alpha__
1da177e4 LT	173	put_user((unsigned long) envp,--sp);
	174	put_user((unsigned long) argv,--sp);
	175	#endif
	176	put_user(argc,--sp);
	177	current->mm->arg_start = (unsigned long) p;
	178	while (argc-->0) {
	179	char c;
	180	put_user(p,argv++);
	181	do {
	182	get_user(c,p++);
	183	} while (c);
	184	}
	185	put_user(NULL,argv);
	186	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	187	while (envc-->0) {
	188	char c;
	189	put_user(p,envp++);
	190	do {
	191	get_user(c,p++);
	192	} while (c);
	193	}
	194	put_user(NULL,envp);
	195	current->mm->env_end = (unsigned long) p;
	196	return sp;
	197	}
	198
	199	/*
	200	* These are the functions used to load a.out style executables and shared
	201	* libraries. There is no binary dependent code anywhere else.
	202	*/
	203
71613c3b	204	static int load_aout_binary(struct linux_binprm * bprm)
1da177e4	205	{
71613c3b	206	struct pt_regs *regs = current_pt_regs();
1da177e4 LT	207	struct exec ex;
	208	unsigned long error;
	209	unsigned long fd_offset;
	210	unsigned long rlim;
	211	int retval;
	212
	213	ex = ((struct exec ) bprm->buf); /* exec-header */
	214	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
	215	N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) \|\|
	216	N_TRSIZE(ex) \|\| N_DRSIZE(ex) \|\|
496ad9aa	217	i_size_read(file_inode(bprm->file)) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
1da177e4 LT	218	return -ENOEXEC;
	219	}
	220
8454aeef ET	221	/*
	222	* Requires a mmap handler. This prevents people from using a.out
	223	* as part of an exploit attack against /proc-related vulnerabilities.
	224	*/
	225	if (!bprm->file->f_op \|\| !bprm->file->f_op->mmap)
	226	return -ENOEXEC;
	227
1da177e4 LT	228	fd_offset = N_TXTOFF(ex);
	229
	230	/* Check initial limits. This avoids letting people circumvent
	231	* size limits imposed on them by creating programs with large
	232	* arrays in the data or bss.
	233	*/
d554ed89	234	rlim = rlimit(RLIMIT_DATA);
1da177e4 LT	235	if (rlim >= RLIM_INFINITY)
	236	rlim = ~0;
	237	if (ex.a_data + ex.a_bss > rlim)
	238	return -ENOMEM;
	239
	240	/* Flush all traces of the currently running executable */
	241	retval = flush_old_exec(bprm);
	242	if (retval)
	243	return retval;
	244
	245	/* OK, This is the point of no return */
17580d7f	246	#ifdef __alpha__
1da177e4	247	SET_AOUT_PERSONALITY(bprm, ex);
1da177e4 LT	248	#else
	249	set_personality(PER_LINUX);
	250	#endif
221af7f8	251	setup_new_exec(bprm);
1da177e4 LT	252
	253	current->mm->end_code = ex.a_text +
	254	(current->mm->start_code = N_TXTADDR(ex));
	255	current->mm->end_data = ex.a_data +
	256	(current->mm->start_data = N_DATADDR(ex));
	257	current->mm->brk = ex.a_bss +
	258	(current->mm->start_brk = N_BSSADDR(ex));
	259	current->mm->free_area_cache = current->mm->mmap_base;
1363c3cd	260	current->mm->cached_hole_size = 0;
1da177e4	261
6414fa6a AV	262	retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
	263	if (retval < 0) {
	264	/* Someone check-me: is this error path enough? */
	265	send_sig(SIGKILL, current, 0);
	266	return retval;
	267	}
	268
a6f76f23	269	install_exec_creds(bprm);
1da177e4 LT	270
	271	if (N_MAGIC(ex) == OMAGIC) {
	272	unsigned long text_addr, map_size;
	273	loff_t pos;
	274
	275	text_addr = N_TXTADDR(ex);
	276
fe30af97	277	#ifdef __alpha__
1da177e4 LT	278	pos = fd_offset;
	279	map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
	280	#else
	281	pos = 32;
	282	map_size = ex.a_text+ex.a_data;
	283	#endif
e4eb1ff6	284	error = vm_brk(text_addr & PAGE_MASK, map_size);
1da177e4 LT	285	if (error != (text_addr & PAGE_MASK)) {
	286	send_sig(SIGKILL, current, 0);
	287	return error;
	288	}
	289
	290	error = bprm->file->f_op->read(bprm->file,
	291	(char __user *)text_addr,
	292	ex.a_text+ex.a_data, &pos);
	293	if ((signed long)error < 0) {
	294	send_sig(SIGKILL, current, 0);
	295	return error;
	296	}
	297
	298	flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
	299	} else {
1da177e4	300	if ((ex.a_text & 0xfff \|\| ex.a_data & 0xfff) &&
2e50b6cc	301	(N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
1da177e4 LT	302	{
1da177e4 LT	303	printk(KERN_NOTICE "executable not page aligned\n");
1da177e4 LT	304	}
1da177e4 LT	305
2e50b6cc	306	if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
1da177e4 LT	307	{
	308	printk(KERN_WARNING
	309	"fd_offset is not page aligned. Please convert program: %s\n",
0f7fc9e4	310	bprm->file->f_path.dentry->d_name.name);
1da177e4 LT	311	}
	312
	313	if (!bprm->file->f_op->mmap\|\|((fd_offset & ~PAGE_MASK) != 0)) {
	314	loff_t pos = fd_offset;
e4eb1ff6	315	vm_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
1da177e4 LT	316	bprm->file->f_op->read(bprm->file,
	317	(char __user *)N_TXTADDR(ex),
	318	ex.a_text+ex.a_data, &pos);
	319	flush_icache_range((unsigned long) N_TXTADDR(ex),
	320	(unsigned long) N_TXTADDR(ex) +
	321	ex.a_text+ex.a_data);
	322	goto beyond_if;
	323	}
	324
6be5ceb0	325	error = vm_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
1da177e4 LT	326	PROT_READ \| PROT_EXEC,
	327	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	328	fd_offset);
1da177e4 LT	329
	330	if (error != N_TXTADDR(ex)) {
	331	send_sig(SIGKILL, current, 0);
	332	return error;
	333	}
	334
6be5ceb0	335	error = vm_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
1da177e4 LT	336	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	337	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	338	fd_offset + ex.a_text);
1da177e4 LT	339	if (error != N_DATADDR(ex)) {
	340	send_sig(SIGKILL, current, 0);
	341	return error;
	342	}
	343	}
	344	beyond_if:
	345	set_binfmt(&aout_format);
	346
	347	retval = set_brk(current->mm->start_brk, current->mm->brk);
	348	if (retval < 0) {
	349	send_sig(SIGKILL, current, 0);
	350	return retval;
	351	}
	352
1da177e4 LT	353	current->mm->start_stack =
	354	(unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
	355	#ifdef __alpha__
	356	regs->gp = ex.a_gpvalue;
	357	#endif
	358	start_thread(regs, ex.a_entry, current->mm->start_stack);
1da177e4 LT	359	return 0;
	360	}
	361
	362	static int load_aout_library(struct file *file)
	363	{
	364	struct inode * inode;
	365	unsigned long bss, start_addr, len;
	366	unsigned long error;
	367	int retval;
	368	struct exec ex;
	369
496ad9aa	370	inode = file_inode(file);
1da177e4 LT	371
	372	retval = -ENOEXEC;
	373	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
	374	if (error != sizeof(ex))
	375	goto out;
	376
	377	/* We come in here for the regular a.out style of shared libraries */
	378	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) \|\| N_TRSIZE(ex) \|\|
	379	N_DRSIZE(ex) \|\| ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) \|\|
	380	i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
	381	goto out;
	382	}
	383
8454aeef ET	384	/*
	385	* Requires a mmap handler. This prevents people from using a.out
	386	* as part of an exploit attack against /proc-related vulnerabilities.
	387	*/
	388	if (!file->f_op \|\| !file->f_op->mmap)
	389	goto out;
	390
1da177e4 LT	391	if (N_FLAGS(ex))
	392	goto out;
	393
	394	/* For QMAGIC, the starting address is 0x20 into the page. We mask
	395	this off to get the starting address for the page */
	396
	397	start_addr = ex.a_entry & 0xfffff000;
	398
	399	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
1da177e4 LT	400	loff_t pos = N_TXTOFF(ex);
1da177e4 LT	401
2e50b6cc	402	if (printk_ratelimit())
1da177e4 LT	403	{
	404	printk(KERN_WARNING
	405	"N_TXTOFF is not page aligned. Please convert library: %s\n",
0f7fc9e4	406	file->f_path.dentry->d_name.name);
1da177e4	407	}
e4eb1ff6	408	vm_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
1da177e4 LT	409
	410	file->f_op->read(file, (char __user *)start_addr,
	411	ex.a_text + ex.a_data, &pos);
	412	flush_icache_range((unsigned long) start_addr,
	413	(unsigned long) start_addr + ex.a_text + ex.a_data);
	414
	415	retval = 0;
	416	goto out;
	417	}
	418	/* Now use mmap to map the library into memory. */
6be5ceb0	419	error = vm_mmap(file, start_addr, ex.a_text + ex.a_data,
1da177e4 LT	420	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	421	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE,
	422	N_TXTOFF(ex));
1da177e4 LT	423	retval = error;
	424	if (error != start_addr)
	425	goto out;
	426
	427	len = PAGE_ALIGN(ex.a_text + ex.a_data);
	428	bss = ex.a_text + ex.a_data + ex.a_bss;
	429	if (bss > len) {
e4eb1ff6	430	error = vm_brk(start_addr + len, bss - len);
1da177e4 LT	431	retval = error;
	432	if (error != start_addr + len)
	433	goto out;
	434	}
	435	retval = 0;
	436	out:
	437	return retval;
	438	}
	439
	440	static int __init init_aout_binfmt(void)
	441	{
8fc3dc5a AV	442	register_binfmt(&aout_format);
8fc3dc5a AV	443	return 0;
1da177e4 LT	444	}
	445
	446	static void __exit exit_aout_binfmt(void)
	447	{
	448	unregister_binfmt(&aout_format);
	449	}
	450
	451	core_initcall(init_aout_binfmt);
	452	module_exit(exit_aout_binfmt);
	453	MODULE_LICENSE("GPL");