[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/system.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/a.out-core.h>

static int load_aout_binary(struct linux_binprm *, struct pt_regs * regs);
static int load_aout_library(struct file*);
static int aout_core_dump(struct coredump_params *cprm);

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;
		down_write(&current->mm->mmap_sem);
		addr = do_brk(start, end - start);
		up_write(&current->mm->mmap_sem);
		if (BAD_ADDR(addr))
			return addr;
	}
	return 0;
}

/*
 * 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->signr;
	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;
}

/*
 * 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)
{
	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(bprm->file->f_path.dentry->d_inode) < 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;

	install_exec_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;

	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
		down_write(&current->mm->mmap_sem);
		error = do_brk(text_addr & PAGE_MASK, map_size);
		up_write(&current->mm->mmap_sem);
		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;
			down_write(&current->mm->mmap_sem);
			do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
			up_write(&current->mm->mmap_sem);
			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;
		}

		down_write(&current->mm->mmap_sem);
		error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
			PROT_READ | PROT_EXEC,
			MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE,
			fd_offset);
		up_write(&current->mm->mmap_sem);

		if (error != N_TXTADDR(ex)) {
			send_sig(SIGKILL, current, 0);
			return error;
		}

		down_write(&current->mm->mmap_sem);
 		error = do_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);
		up_write(&current->mm->mmap_sem);
		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;
	}

	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;
	}

	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->f_path.dentry->d_inode;

	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);
		}
		down_write(&current->mm->mmap_sem);
		do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
		up_write(&current->mm->mmap_sem);
		
		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. */
	down_write(&current->mm->mmap_sem);
	error = do_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));
	up_write(&current->mm->mmap_sem);
	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) {
		down_write(&current->mm->mmap_sem);
		error = do_brk(start_addr + len, bss - len);
		up_write(&current->mm->mmap_sem);
		retval = error;
		if (error != start_addr + len)
			goto out;
	}
	retval = 0;
out:
	return retval;
}

static int __init init_aout_binfmt(void)
{
	return register_binfmt(&aout_format);
}

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 LT	28
	29	#include <asm/system.h>
	30	#include <asm/uaccess.h>
	31	#include <asm/cacheflush.h>
7fa30315	32	#include <asm/a.out-core.h>
1da177e4 LT	33
	34	static int load_aout_binary(struct linux_binprm , struct pt_regs regs);
	35	static int load_aout_library(struct file*);
f6151dfe	36	static int aout_core_dump(struct coredump_params *cprm);
1da177e4	37
1da177e4 LT	38	static struct linux_binfmt aout_format = {
	39	.module = THIS_MODULE,
	40	.load_binary = load_aout_binary,
	41	.load_shlib = load_aout_library,
	42	.core_dump = aout_core_dump,
	43	.min_coredump = PAGE_SIZE
	44	};
	45
	46	#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
	47
	48	static int set_brk(unsigned long start, unsigned long end)
	49	{
	50	start = PAGE_ALIGN(start);
	51	end = PAGE_ALIGN(end);
	52	if (end > start) {
	53	unsigned long addr;
	54	down_write(&current->mm->mmap_sem);
	55	addr = do_brk(start, end - start);
	56	up_write(&current->mm->mmap_sem);
	57	if (BAD_ADDR(addr))
	58	return addr;
	59	}
	60	return 0;
	61	}
	62
1da177e4 LT	63	/*
	64	* Routine writes a core dump image in the current directory.
	65	* Currently only a stub-function.
	66	*
	67	* Note that setuid/setgid files won't make a core-dump if the uid/gid
	68	* changed due to the set[u\|g]id. It's enforced by the "current->mm->dumpable"
	69	* field, which also makes sure the core-dumps won't be recursive if the
	70	* dumping of the process results in another error..
	71	*/
	72
f6151dfe	73	static int aout_core_dump(struct coredump_params *cprm)
1da177e4	74	{
f6151dfe	75	struct file *file = cprm->file;
1da177e4 LT	76	mm_segment_t fs;
1da177e4 LT	77	int has_dumped = 0;
7731d9a5 BP	78	void __user *dump_start;
7731d9a5 BP	79	int dump_size;
1da177e4	80	struct user dump;
17580d7f	81	#ifdef __alpha__
7731d9a5	82	# define START_DATA(u) ((void __user *)u.start_data)
17580d7f	83	#else
7731d9a5 BP	84	# define START_DATA(u) ((void __user *)((u.u_tsize << PAGE_SHIFT) + \
7731d9a5 BP	85	u.start_code))
1da177e4	86	#endif
7731d9a5	87	# define START_STACK(u) ((void __user *)u.start_stack)
1da177e4 LT	88
	89	fs = get_fs();
	90	set_fs(KERNEL_DS);
	91	has_dumped = 1;
	92	current->flags \|= PF_DUMPCORE;
	93	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
6e16d89b	94	dump.u_ar0 = offsetof(struct user, regs);
f6151dfe MH	95	dump.signal = cprm->signr;
f6151dfe MH	96	aout_dump_thread(cprm->regs, &dump);
1da177e4 LT	97
	98	/* If the size of the dump file exceeds the rlimit, then see what would happen
	99	if we wrote the stack, but not the data area. */
f6151dfe	100	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > cprm->limit)
1da177e4	101	dump.u_dsize = 0;
1da177e4 LT	102
1da177e4 LT	103	/* Make sure we have enough room to write the stack and data areas. */
f6151dfe	104	if ((dump.u_ssize + 1) * PAGE_SIZE > cprm->limit)
1da177e4	105	dump.u_ssize = 0;
1da177e4 LT	106
	107	/* make sure we actually have a data and stack area to dump */
	108	set_fs(USER_DS);
7731d9a5	109	if (!access_ok(VERIFY_READ, START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
1da177e4	110	dump.u_dsize = 0;
7731d9a5	111	if (!access_ok(VERIFY_READ, START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
1da177e4	112	dump.u_ssize = 0;
1da177e4 LT	113
	114	set_fs(KERNEL_DS);
	115	/* struct user */
088e7af7 DH	116	if (!dump_write(file, &dump, sizeof(dump)))
088e7af7 DH	117	goto end_coredump;
1da177e4	118	/* Now dump all of the user data. Include malloced stuff as well */
05f47fda DH	119	if (!dump_seek(cprm->file, PAGE_SIZE - sizeof(dump)))
05f47fda DH	120	goto end_coredump;
1da177e4 LT	121	/* now we start writing out the user space info */
	122	set_fs(USER_DS);
	123	/* Dump the data area */
	124	if (dump.u_dsize != 0) {
	125	dump_start = START_DATA(dump);
1da177e4	126	dump_size = dump.u_dsize << PAGE_SHIFT;
088e7af7 DH	127	if (!dump_write(file, dump_start, dump_size))
088e7af7 DH	128	goto end_coredump;
1da177e4 LT	129	}
	130	/* Now prepare to dump the stack area */
	131	if (dump.u_ssize != 0) {
	132	dump_start = START_STACK(dump);
1da177e4	133	dump_size = dump.u_ssize << PAGE_SHIFT;
088e7af7 DH	134	if (!dump_write(file, dump_start, dump_size))
088e7af7 DH	135	goto end_coredump;
1da177e4	136	}
1da177e4 LT	137	end_coredump:
	138	set_fs(fs);
	139	return has_dumped;
	140	}
	141
	142	/*
	143	* create_aout_tables() parses the env- and arg-strings in new user
	144	* memory and creates the pointer tables from them, and puts their
	145	* addresses on the "stack", returning the new stack pointer value.
	146	*/
	147	static unsigned long __user create_aout_tables(char __user p, struct linux_binprm * bprm)
	148	{
	149	char __user * __user *argv;
	150	char __user * __user *envp;
	151	unsigned long __user *sp;
	152	int argc = bprm->argc;
	153	int envc = bprm->envc;
	154
	155	sp = (void __user )((-(unsigned long)sizeof(char )) & (unsigned long) p);
1da177e4 LT	156	#ifdef __alpha__
	157	/* whee.. test-programs are so much fun. */
	158	put_user(0, --sp);
	159	put_user(0, --sp);
	160	if (bprm->loader) {
	161	put_user(0, --sp);
17580d7f	162	put_user(1003, --sp);
1da177e4	163	put_user(bprm->loader, --sp);
17580d7f	164	put_user(1002, --sp);
1da177e4 LT	165	}
1da177e4 LT	166	put_user(bprm->exec, --sp);
17580d7f	167	put_user(1001, --sp);
1da177e4 LT	168	#endif
	169	sp -= envc+1;
	170	envp = (char __user * __user *) sp;
	171	sp -= argc+1;
	172	argv = (char __user * __user *) sp;
17580d7f	173	#ifndef __alpha__
1da177e4 LT	174	put_user((unsigned long) envp,--sp);
	175	put_user((unsigned long) argv,--sp);
	176	#endif
	177	put_user(argc,--sp);
	178	current->mm->arg_start = (unsigned long) p;
	179	while (argc-->0) {
	180	char c;
	181	put_user(p,argv++);
	182	do {
	183	get_user(c,p++);
	184	} while (c);
	185	}
	186	put_user(NULL,argv);
	187	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	188	while (envc-->0) {
	189	char c;
	190	put_user(p,envp++);
	191	do {
	192	get_user(c,p++);
	193	} while (c);
	194	}
	195	put_user(NULL,envp);
	196	current->mm->env_end = (unsigned long) p;
	197	return sp;
	198	}
	199
	200	/*
	201	* These are the functions used to load a.out style executables and shared
	202	* libraries. There is no binary dependent code anywhere else.
	203	*/
	204
	205	static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
	206	{
	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) \|\|
0f7fc9e4	217	i_size_read(bprm->file->f_path.dentry->d_inode) < 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
a6f76f23	262	install_exec_creds(bprm);
1da177e4	263	current->flags &= ~PF_FORKNOEXEC;
1da177e4 LT	264
	265	if (N_MAGIC(ex) == OMAGIC) {
	266	unsigned long text_addr, map_size;
	267	loff_t pos;
	268
	269	text_addr = N_TXTADDR(ex);
	270
fe30af97	271	#ifdef __alpha__
1da177e4 LT	272	pos = fd_offset;
	273	map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
	274	#else
	275	pos = 32;
	276	map_size = ex.a_text+ex.a_data;
	277	#endif
	278	down_write(&current->mm->mmap_sem);
	279	error = do_brk(text_addr & PAGE_MASK, map_size);
	280	up_write(&current->mm->mmap_sem);
	281	if (error != (text_addr & PAGE_MASK)) {
	282	send_sig(SIGKILL, current, 0);
	283	return error;
	284	}
	285
	286	error = bprm->file->f_op->read(bprm->file,
	287	(char __user *)text_addr,
	288	ex.a_text+ex.a_data, &pos);
	289	if ((signed long)error < 0) {
	290	send_sig(SIGKILL, current, 0);
	291	return error;
	292	}
	293
	294	flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
	295	} else {
1da177e4	296	if ((ex.a_text & 0xfff \|\| ex.a_data & 0xfff) &&
2e50b6cc	297	(N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
1da177e4 LT	298	{
1da177e4 LT	299	printk(KERN_NOTICE "executable not page aligned\n");
1da177e4 LT	300	}
1da177e4 LT	301
2e50b6cc	302	if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
1da177e4 LT	303	{
	304	printk(KERN_WARNING
	305	"fd_offset is not page aligned. Please convert program: %s\n",
0f7fc9e4	306	bprm->file->f_path.dentry->d_name.name);
1da177e4 LT	307	}
	308
	309	if (!bprm->file->f_op->mmap\|\|((fd_offset & ~PAGE_MASK) != 0)) {
	310	loff_t pos = fd_offset;
	311	down_write(&current->mm->mmap_sem);
	312	do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
	313	up_write(&current->mm->mmap_sem);
	314	bprm->file->f_op->read(bprm->file,
	315	(char __user *)N_TXTADDR(ex),
	316	ex.a_text+ex.a_data, &pos);
	317	flush_icache_range((unsigned long) N_TXTADDR(ex),
	318	(unsigned long) N_TXTADDR(ex) +
	319	ex.a_text+ex.a_data);
	320	goto beyond_if;
	321	}
	322
	323	down_write(&current->mm->mmap_sem);
	324	error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
	325	PROT_READ \| PROT_EXEC,
	326	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	327	fd_offset);
	328	up_write(&current->mm->mmap_sem);
	329
	330	if (error != N_TXTADDR(ex)) {
	331	send_sig(SIGKILL, current, 0);
	332	return error;
	333	}
	334
	335	down_write(&current->mm->mmap_sem);
	336	error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
	337	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	338	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	339	fd_offset + ex.a_text);
	340	up_write(&current->mm->mmap_sem);
	341	if (error != N_DATADDR(ex)) {
	342	send_sig(SIGKILL, current, 0);
	343	return error;
	344	}
	345	}
	346	beyond_if:
	347	set_binfmt(&aout_format);
	348
	349	retval = set_brk(current->mm->start_brk, current->mm->brk);
	350	if (retval < 0) {
	351	send_sig(SIGKILL, current, 0);
	352	return retval;
	353	}
	354
	355	retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
	356	if (retval < 0) {
	357	/* Someone check-me: is this error path enough? */
	358	send_sig(SIGKILL, current, 0);
	359	return retval;
	360	}
	361
	362	current->mm->start_stack =
	363	(unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
	364	#ifdef __alpha__
	365	regs->gp = ex.a_gpvalue;
	366	#endif
	367	start_thread(regs, ex.a_entry, current->mm->start_stack);
1da177e4 LT	368	return 0;
	369	}
	370
	371	static int load_aout_library(struct file *file)
	372	{
	373	struct inode * inode;
	374	unsigned long bss, start_addr, len;
	375	unsigned long error;
	376	int retval;
	377	struct exec ex;
	378
0f7fc9e4	379	inode = file->f_path.dentry->d_inode;
1da177e4 LT	380
	381	retval = -ENOEXEC;
	382	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
	383	if (error != sizeof(ex))
	384	goto out;
	385
	386	/* We come in here for the regular a.out style of shared libraries */
	387	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) \|\| N_TRSIZE(ex) \|\|
	388	N_DRSIZE(ex) \|\| ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) \|\|
	389	i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
	390	goto out;
	391	}
	392
8454aeef ET	393	/*
	394	* Requires a mmap handler. This prevents people from using a.out
	395	* as part of an exploit attack against /proc-related vulnerabilities.
	396	*/
	397	if (!file->f_op \|\| !file->f_op->mmap)
	398	goto out;
	399
1da177e4 LT	400	if (N_FLAGS(ex))
	401	goto out;
	402
	403	/* For QMAGIC, the starting address is 0x20 into the page. We mask
	404	this off to get the starting address for the page */
	405
	406	start_addr = ex.a_entry & 0xfffff000;
	407
	408	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
1da177e4 LT	409	loff_t pos = N_TXTOFF(ex);
1da177e4 LT	410
2e50b6cc	411	if (printk_ratelimit())
1da177e4 LT	412	{
	413	printk(KERN_WARNING
	414	"N_TXTOFF is not page aligned. Please convert library: %s\n",
0f7fc9e4	415	file->f_path.dentry->d_name.name);
1da177e4 LT	416	}
	417	down_write(&current->mm->mmap_sem);
	418	do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
	419	up_write(&current->mm->mmap_sem);
	420
	421	file->f_op->read(file, (char __user *)start_addr,
	422	ex.a_text + ex.a_data, &pos);
	423	flush_icache_range((unsigned long) start_addr,
	424	(unsigned long) start_addr + ex.a_text + ex.a_data);
	425
	426	retval = 0;
	427	goto out;
	428	}
	429	/* Now use mmap to map the library into memory. */
	430	down_write(&current->mm->mmap_sem);
	431	error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
	432	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	433	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE,
	434	N_TXTOFF(ex));
	435	up_write(&current->mm->mmap_sem);
	436	retval = error;
	437	if (error != start_addr)
	438	goto out;
	439
	440	len = PAGE_ALIGN(ex.a_text + ex.a_data);
	441	bss = ex.a_text + ex.a_data + ex.a_bss;
	442	if (bss > len) {
	443	down_write(&current->mm->mmap_sem);
	444	error = do_brk(start_addr + len, bss - len);
	445	up_write(&current->mm->mmap_sem);
	446	retval = error;
	447	if (error != start_addr + len)
	448	goto out;
	449	}
	450	retval = 0;
	451	out:
	452	return retval;
	453	}
	454
	455	static int __init init_aout_binfmt(void)
	456	{
	457	return register_binfmt(&aout_format);
	458	}
	459
	460	static void __exit exit_aout_binfmt(void)
	461	{
	462	unregister_binfmt(&aout_format);
	463	}
	464
	465	core_initcall(init_aout_binfmt);
	466	module_exit(exit_aout_binfmt);
	467	MODULE_LICENSE("GPL");