[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/slab.h>
#include <linux/binfmts.h>
#include <linux/personality.h>
#include <linux/init.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(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);

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;
}

/*
 * These are the only things you should do on a core-file: use only these
 * macros to write out all the necessary info.
 */

static int dump_write(struct file *file, const void *addr, int nr)
{
	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
}

#define DUMP_WRITE(addr, nr)	\
	if (!dump_write(file, (void *)(addr), (nr))) \
		goto end_coredump;

#define DUMP_SEEK(offset) \
if (file->f_op->llseek) { \
	if (file->f_op->llseek(file,(offset),0) != (offset)) \
 		goto end_coredump; \
} else file->f_pos = (offset)

/*
 * 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(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
{
	mm_segment_t fs;
	int has_dumped = 0;
	unsigned long dump_start, dump_size;
	struct user dump;
#ifdef __alpha__
#       define START_DATA(u)	(u.start_data)
#else
#	define START_DATA(u)	((u.u_tsize << PAGE_SHIFT) + u.start_code)
#endif
#       define START_STACK(u)   (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 = signr;
	aout_dump_thread(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 > 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 > 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, (void __user *)START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
		dump.u_dsize = 0;
	if (!access_ok(VERIFY_READ, (void __user *)START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
		dump.u_ssize = 0;

	set_fs(KERNEL_DS);
/* struct user */
	DUMP_WRITE(&dump,sizeof(dump));
/* Now dump all of the user data.  Include malloced stuff as well */
	DUMP_SEEK(PAGE_SIZE);
/* 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;
		DUMP_WRITE(dump_start,dump_size);
	}
/* Now prepare to dump the stack area */
	if (dump.u_ssize != 0) {
		dump_start = START_STACK(dump);
		dump_size = dump.u_ssize << PAGE_SHIFT;
		DUMP_WRITE(dump_start,dump_size);
	}
/* Finally dump the task struct.  Not be used by gdb, but could be useful */
	set_fs(KERNEL_DS);
	DUMP_WRITE(current,sizeof(*current));
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 = current->signal->rlim[RLIMIT_DATA].rlim_cur;
	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

	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>
	23	#include <linux/slab.h>
	24	#include <linux/binfmts.h>
	25	#include <linux/personality.h>
	26	#include <linux/init.h>
	27
	28	#include <asm/system.h>
	29	#include <asm/uaccess.h>
	30	#include <asm/cacheflush.h>
7fa30315	31	#include <asm/a.out-core.h>
1da177e4 LT	32
	33	static int load_aout_binary(struct linux_binprm , struct pt_regs regs);
	34	static int load_aout_library(struct file*);
7dc0b22e	35	static int aout_core_dump(long signr, struct pt_regs regs, struct file file, unsigned long limit);
1da177e4	36
1da177e4 LT	37	static struct linux_binfmt aout_format = {
	38	.module = THIS_MODULE,
	39	.load_binary = load_aout_binary,
	40	.load_shlib = load_aout_library,
	41	.core_dump = aout_core_dump,
	42	.min_coredump = PAGE_SIZE
	43	};
	44
	45	#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
	46
	47	static int set_brk(unsigned long start, unsigned long end)
	48	{
	49	start = PAGE_ALIGN(start);
	50	end = PAGE_ALIGN(end);
	51	if (end > start) {
	52	unsigned long addr;
	53	down_write(&current->mm->mmap_sem);
	54	addr = do_brk(start, end - start);
	55	up_write(&current->mm->mmap_sem);
	56	if (BAD_ADDR(addr))
	57	return addr;
	58	}
	59	return 0;
	60	}
	61
	62	/*
	63	* These are the only things you should do on a core-file: use only these
	64	* macros to write out all the necessary info.
	65	*/
	66
	67	static int dump_write(struct file file, const void addr, int nr)
	68	{
	69	return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
	70	}
	71
	72	#define DUMP_WRITE(addr, nr) \
	73	if (!dump_write(file, (void *)(addr), (nr))) \
	74	goto end_coredump;
	75
	76	#define DUMP_SEEK(offset) \
	77	if (file->f_op->llseek) { \
	78	if (file->f_op->llseek(file,(offset),0) != (offset)) \
	79	goto end_coredump; \
	80	} else file->f_pos = (offset)
	81
	82	/*
	83	* Routine writes a core dump image in the current directory.
	84	* Currently only a stub-function.
	85	*
	86	* Note that setuid/setgid files won't make a core-dump if the uid/gid
	87	* changed due to the set[u\|g]id. It's enforced by the "current->mm->dumpable"
	88	* field, which also makes sure the core-dumps won't be recursive if the
	89	* dumping of the process results in another error..
	90	*/
	91
7dc0b22e	92	static int aout_core_dump(long signr, struct pt_regs regs, struct file file, unsigned long limit)
1da177e4 LT	93	{
	94	mm_segment_t fs;
	95	int has_dumped = 0;
	96	unsigned long dump_start, dump_size;
	97	struct user dump;
17580d7f	98	#ifdef __alpha__
1da177e4	99	# define START_DATA(u) (u.start_data)
17580d7f	100	#else
1da177e4	101	# define START_DATA(u) ((u.u_tsize << PAGE_SHIFT) + u.start_code)
1da177e4	102	#endif
1da177e4	103	# define START_STACK(u) (u.start_stack)
1da177e4 LT	104
	105	fs = get_fs();
	106	set_fs(KERNEL_DS);
	107	has_dumped = 1;
	108	current->flags \|= PF_DUMPCORE;
	109	strncpy(dump.u_comm, current->comm, sizeof(dump.u_comm));
6e16d89b	110	dump.u_ar0 = offsetof(struct user, regs);
1da177e4	111	dump.signal = signr;
7fa30315	112	aout_dump_thread(regs, &dump);
1da177e4 LT	113
	114	/* If the size of the dump file exceeds the rlimit, then see what would happen
	115	if we wrote the stack, but not the data area. */
7dc0b22e	116	if ((dump.u_dsize + dump.u_ssize+1) * PAGE_SIZE > limit)
1da177e4	117	dump.u_dsize = 0;
1da177e4 LT	118
1da177e4 LT	119	/* Make sure we have enough room to write the stack and data areas. */
7dc0b22e	120	if ((dump.u_ssize + 1) * PAGE_SIZE > limit)
1da177e4	121	dump.u_ssize = 0;
1da177e4 LT	122
	123	/* make sure we actually have a data and stack area to dump */
	124	set_fs(USER_DS);
1da177e4 LT	125	if (!access_ok(VERIFY_READ, (void __user *)START_DATA(dump), dump.u_dsize << PAGE_SHIFT))
	126	dump.u_dsize = 0;
	127	if (!access_ok(VERIFY_READ, (void __user *)START_STACK(dump), dump.u_ssize << PAGE_SHIFT))
	128	dump.u_ssize = 0;
1da177e4 LT	129
	130	set_fs(KERNEL_DS);
	131	/* struct user */
	132	DUMP_WRITE(&dump,sizeof(dump));
	133	/* Now dump all of the user data. Include malloced stuff as well */
1da177e4	134	DUMP_SEEK(PAGE_SIZE);
1da177e4 LT	135	/* now we start writing out the user space info */
	136	set_fs(USER_DS);
	137	/* Dump the data area */
	138	if (dump.u_dsize != 0) {
	139	dump_start = START_DATA(dump);
1da177e4	140	dump_size = dump.u_dsize << PAGE_SHIFT;
1da177e4 LT	141	DUMP_WRITE(dump_start,dump_size);
	142	}
	143	/* Now prepare to dump the stack area */
	144	if (dump.u_ssize != 0) {
	145	dump_start = START_STACK(dump);
1da177e4	146	dump_size = dump.u_ssize << PAGE_SHIFT;
1da177e4 LT	147	DUMP_WRITE(dump_start,dump_size);
	148	}
	149	/* Finally dump the task struct. Not be used by gdb, but could be useful */
	150	set_fs(KERNEL_DS);
	151	DUMP_WRITE(current,sizeof(*current));
	152	end_coredump:
	153	set_fs(fs);
	154	return has_dumped;
	155	}
	156
	157	/*
	158	* create_aout_tables() parses the env- and arg-strings in new user
	159	* memory and creates the pointer tables from them, and puts their
	160	* addresses on the "stack", returning the new stack pointer value.
	161	*/
	162	static unsigned long __user create_aout_tables(char __user p, struct linux_binprm * bprm)
	163	{
	164	char __user * __user *argv;
	165	char __user * __user *envp;
	166	unsigned long __user *sp;
	167	int argc = bprm->argc;
	168	int envc = bprm->envc;
	169
	170	sp = (void __user )((-(unsigned long)sizeof(char )) & (unsigned long) p);
1da177e4 LT	171	#ifdef __alpha__
	172	/* whee.. test-programs are so much fun. */
	173	put_user(0, --sp);
	174	put_user(0, --sp);
	175	if (bprm->loader) {
	176	put_user(0, --sp);
17580d7f	177	put_user(1003, --sp);
1da177e4	178	put_user(bprm->loader, --sp);
17580d7f	179	put_user(1002, --sp);
1da177e4 LT	180	}
1da177e4 LT	181	put_user(bprm->exec, --sp);
17580d7f	182	put_user(1001, --sp);
1da177e4 LT	183	#endif
	184	sp -= envc+1;
	185	envp = (char __user * __user *) sp;
	186	sp -= argc+1;
	187	argv = (char __user * __user *) sp;
17580d7f	188	#ifndef __alpha__
1da177e4 LT	189	put_user((unsigned long) envp,--sp);
	190	put_user((unsigned long) argv,--sp);
	191	#endif
	192	put_user(argc,--sp);
	193	current->mm->arg_start = (unsigned long) p;
	194	while (argc-->0) {
	195	char c;
	196	put_user(p,argv++);
	197	do {
	198	get_user(c,p++);
	199	} while (c);
	200	}
	201	put_user(NULL,argv);
	202	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	203	while (envc-->0) {
	204	char c;
	205	put_user(p,envp++);
	206	do {
	207	get_user(c,p++);
	208	} while (c);
	209	}
	210	put_user(NULL,envp);
	211	current->mm->env_end = (unsigned long) p;
	212	return sp;
	213	}
	214
	215	/*
	216	* These are the functions used to load a.out style executables and shared
	217	* libraries. There is no binary dependent code anywhere else.
	218	*/
	219
	220	static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
	221	{
	222	struct exec ex;
	223	unsigned long error;
	224	unsigned long fd_offset;
	225	unsigned long rlim;
	226	int retval;
	227
	228	ex = ((struct exec ) bprm->buf); /* exec-header */
	229	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
	230	N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) \|\|
	231	N_TRSIZE(ex) \|\| N_DRSIZE(ex) \|\|
0f7fc9e4	232	i_size_read(bprm->file->f_path.dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
1da177e4 LT	233	return -ENOEXEC;
	234	}
	235
8454aeef ET	236	/*
	237	* Requires a mmap handler. This prevents people from using a.out
	238	* as part of an exploit attack against /proc-related vulnerabilities.
	239	*/
	240	if (!bprm->file->f_op \|\| !bprm->file->f_op->mmap)
	241	return -ENOEXEC;
	242
1da177e4 LT	243	fd_offset = N_TXTOFF(ex);
	244
	245	/* Check initial limits. This avoids letting people circumvent
	246	* size limits imposed on them by creating programs with large
	247	* arrays in the data or bss.
	248	*/
	249	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
	250	if (rlim >= RLIM_INFINITY)
	251	rlim = ~0;
	252	if (ex.a_data + ex.a_bss > rlim)
	253	return -ENOMEM;
	254
	255	/* Flush all traces of the currently running executable */
	256	retval = flush_old_exec(bprm);
	257	if (retval)
	258	return retval;
	259
	260	/* OK, This is the point of no return */
17580d7f	261	#ifdef __alpha__
1da177e4	262	SET_AOUT_PERSONALITY(bprm, ex);
1da177e4 LT	263	#else
	264	set_personality(PER_LINUX);
	265	#endif
	266
	267	current->mm->end_code = ex.a_text +
	268	(current->mm->start_code = N_TXTADDR(ex));
	269	current->mm->end_data = ex.a_data +
	270	(current->mm->start_data = N_DATADDR(ex));
	271	current->mm->brk = ex.a_bss +
	272	(current->mm->start_brk = N_BSSADDR(ex));
	273	current->mm->free_area_cache = current->mm->mmap_base;
1363c3cd	274	current->mm->cached_hole_size = 0;
1da177e4	275
a6f76f23	276	install_exec_creds(bprm);
1da177e4	277	current->flags &= ~PF_FORKNOEXEC;
1da177e4 LT	278
	279	if (N_MAGIC(ex) == OMAGIC) {
	280	unsigned long text_addr, map_size;
	281	loff_t pos;
	282
	283	text_addr = N_TXTADDR(ex);
	284
fe30af97	285	#ifdef __alpha__
1da177e4 LT	286	pos = fd_offset;
	287	map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
	288	#else
	289	pos = 32;
	290	map_size = ex.a_text+ex.a_data;
	291	#endif
	292	down_write(&current->mm->mmap_sem);
	293	error = do_brk(text_addr & PAGE_MASK, map_size);
	294	up_write(&current->mm->mmap_sem);
	295	if (error != (text_addr & PAGE_MASK)) {
	296	send_sig(SIGKILL, current, 0);
	297	return error;
	298	}
	299
	300	error = bprm->file->f_op->read(bprm->file,
	301	(char __user *)text_addr,
	302	ex.a_text+ex.a_data, &pos);
	303	if ((signed long)error < 0) {
	304	send_sig(SIGKILL, current, 0);
	305	return error;
	306	}
	307
	308	flush_icache_range(text_addr, text_addr+ex.a_text+ex.a_data);
	309	} else {
1da177e4	310	if ((ex.a_text & 0xfff \|\| ex.a_data & 0xfff) &&
2e50b6cc	311	(N_MAGIC(ex) != NMAGIC) && printk_ratelimit())
1da177e4 LT	312	{
1da177e4 LT	313	printk(KERN_NOTICE "executable not page aligned\n");
1da177e4 LT	314	}
1da177e4 LT	315
2e50b6cc	316	if ((fd_offset & ~PAGE_MASK) != 0 && printk_ratelimit())
1da177e4 LT	317	{
	318	printk(KERN_WARNING
	319	"fd_offset is not page aligned. Please convert program: %s\n",
0f7fc9e4	320	bprm->file->f_path.dentry->d_name.name);
1da177e4 LT	321	}
	322
	323	if (!bprm->file->f_op->mmap\|\|((fd_offset & ~PAGE_MASK) != 0)) {
	324	loff_t pos = fd_offset;
	325	down_write(&current->mm->mmap_sem);
	326	do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
	327	up_write(&current->mm->mmap_sem);
	328	bprm->file->f_op->read(bprm->file,
	329	(char __user *)N_TXTADDR(ex),
	330	ex.a_text+ex.a_data, &pos);
	331	flush_icache_range((unsigned long) N_TXTADDR(ex),
	332	(unsigned long) N_TXTADDR(ex) +
	333	ex.a_text+ex.a_data);
	334	goto beyond_if;
	335	}
	336
	337	down_write(&current->mm->mmap_sem);
	338	error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
	339	PROT_READ \| PROT_EXEC,
	340	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	341	fd_offset);
	342	up_write(&current->mm->mmap_sem);
	343
	344	if (error != N_TXTADDR(ex)) {
	345	send_sig(SIGKILL, current, 0);
	346	return error;
	347	}
	348
	349	down_write(&current->mm->mmap_sem);
	350	error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
	351	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	352	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	353	fd_offset + ex.a_text);
	354	up_write(&current->mm->mmap_sem);
	355	if (error != N_DATADDR(ex)) {
	356	send_sig(SIGKILL, current, 0);
	357	return error;
	358	}
	359	}
	360	beyond_if:
	361	set_binfmt(&aout_format);
	362
	363	retval = set_brk(current->mm->start_brk, current->mm->brk);
	364	if (retval < 0) {
	365	send_sig(SIGKILL, current, 0);
	366	return retval;
	367	}
	368
	369	retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
	370	if (retval < 0) {
	371	/* Someone check-me: is this error path enough? */
	372	send_sig(SIGKILL, current, 0);
	373	return retval;
	374	}
	375
	376	current->mm->start_stack =
	377	(unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
	378	#ifdef __alpha__
	379	regs->gp = ex.a_gpvalue;
	380	#endif
	381	start_thread(regs, ex.a_entry, current->mm->start_stack);
1da177e4 LT	382	return 0;
	383	}
	384
	385	static int load_aout_library(struct file *file)
	386	{
	387	struct inode * inode;
	388	unsigned long bss, start_addr, len;
	389	unsigned long error;
	390	int retval;
	391	struct exec ex;
	392
0f7fc9e4	393	inode = file->f_path.dentry->d_inode;
1da177e4 LT	394
	395	retval = -ENOEXEC;
	396	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
	397	if (error != sizeof(ex))
	398	goto out;
	399
	400	/* We come in here for the regular a.out style of shared libraries */
	401	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) \|\| N_TRSIZE(ex) \|\|
	402	N_DRSIZE(ex) \|\| ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) \|\|
	403	i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
	404	goto out;
	405	}
	406
8454aeef ET	407	/*
	408	* Requires a mmap handler. This prevents people from using a.out
	409	* as part of an exploit attack against /proc-related vulnerabilities.
	410	*/
	411	if (!file->f_op \|\| !file->f_op->mmap)
	412	goto out;
	413
1da177e4 LT	414	if (N_FLAGS(ex))
	415	goto out;
	416
	417	/* For QMAGIC, the starting address is 0x20 into the page. We mask
	418	this off to get the starting address for the page */
	419
	420	start_addr = ex.a_entry & 0xfffff000;
	421
	422	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
1da177e4 LT	423	loff_t pos = N_TXTOFF(ex);
1da177e4 LT	424
2e50b6cc	425	if (printk_ratelimit())
1da177e4 LT	426	{
	427	printk(KERN_WARNING
	428	"N_TXTOFF is not page aligned. Please convert library: %s\n",
0f7fc9e4	429	file->f_path.dentry->d_name.name);
1da177e4 LT	430	}
	431	down_write(&current->mm->mmap_sem);
	432	do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
	433	up_write(&current->mm->mmap_sem);
	434
	435	file->f_op->read(file, (char __user *)start_addr,
	436	ex.a_text + ex.a_data, &pos);
	437	flush_icache_range((unsigned long) start_addr,
	438	(unsigned long) start_addr + ex.a_text + ex.a_data);
	439
	440	retval = 0;
	441	goto out;
	442	}
	443	/* Now use mmap to map the library into memory. */
	444	down_write(&current->mm->mmap_sem);
	445	error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
	446	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	447	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE,
	448	N_TXTOFF(ex));
	449	up_write(&current->mm->mmap_sem);
	450	retval = error;
	451	if (error != start_addr)
	452	goto out;
	453
	454	len = PAGE_ALIGN(ex.a_text + ex.a_data);
	455	bss = ex.a_text + ex.a_data + ex.a_bss;
	456	if (bss > len) {
	457	down_write(&current->mm->mmap_sem);
	458	error = do_brk(start_addr + len, bss - len);
	459	up_write(&current->mm->mmap_sem);
	460	retval = error;
	461	if (error != start_addr + len)
	462	goto out;
	463	}
	464	retval = 0;
	465	out:
	466	return retval;
	467	}
	468
	469	static int __init init_aout_binfmt(void)
	470	{
	471	return register_binfmt(&aout_format);
	472	}
	473
	474	static void __exit exit_aout_binfmt(void)
	475	{
	476	unregister_binfmt(&aout_format);
	477	}
	478
	479	core_initcall(init_aout_binfmt);
	480	module_exit(exit_aout_binfmt);
	481	MODULE_LICENSE("GPL");