[net-next-2.6.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 <linux/coredump.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;
	}
/* Finally dump the task struct.  Not be used by gdb, but could be useful */
	set_fs(KERNEL_DS);
	if (!dump_write(file, current, sizeof(*current)))
		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>
	23	#include <linux/slab.h>
	24	#include <linux/binfmts.h>
	25	#include <linux/personality.h>
	26	#include <linux/init.h>
088e7af7	27	#include <linux/coredump.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 LT	136	}
	137	/* Finally dump the task struct. Not be used by gdb, but could be useful */
	138	set_fs(KERNEL_DS);
088e7af7 DH	139	if (!dump_write(file, current, sizeof(*current)))
088e7af7 DH	140	goto end_coredump;
1da177e4 LT	141	end_coredump:
	142	set_fs(fs);
	143	return has_dumped;
	144	}
	145
	146	/*
	147	* create_aout_tables() parses the env- and arg-strings in new user
	148	* memory and creates the pointer tables from them, and puts their
	149	* addresses on the "stack", returning the new stack pointer value.
	150	*/
	151	static unsigned long __user create_aout_tables(char __user p, struct linux_binprm * bprm)
	152	{
	153	char __user * __user *argv;
	154	char __user * __user *envp;
	155	unsigned long __user *sp;
	156	int argc = bprm->argc;
	157	int envc = bprm->envc;
	158
	159	sp = (void __user )((-(unsigned long)sizeof(char )) & (unsigned long) p);
1da177e4 LT	160	#ifdef __alpha__
	161	/* whee.. test-programs are so much fun. */
	162	put_user(0, --sp);
	163	put_user(0, --sp);
	164	if (bprm->loader) {
	165	put_user(0, --sp);
17580d7f	166	put_user(1003, --sp);
1da177e4	167	put_user(bprm->loader, --sp);
17580d7f	168	put_user(1002, --sp);
1da177e4 LT	169	}
1da177e4 LT	170	put_user(bprm->exec, --sp);
17580d7f	171	put_user(1001, --sp);
1da177e4 LT	172	#endif
	173	sp -= envc+1;
	174	envp = (char __user * __user *) sp;
	175	sp -= argc+1;
	176	argv = (char __user * __user *) sp;
17580d7f	177	#ifndef __alpha__
1da177e4 LT	178	put_user((unsigned long) envp,--sp);
	179	put_user((unsigned long) argv,--sp);
	180	#endif
	181	put_user(argc,--sp);
	182	current->mm->arg_start = (unsigned long) p;
	183	while (argc-->0) {
	184	char c;
	185	put_user(p,argv++);
	186	do {
	187	get_user(c,p++);
	188	} while (c);
	189	}
	190	put_user(NULL,argv);
	191	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	192	while (envc-->0) {
	193	char c;
	194	put_user(p,envp++);
	195	do {
	196	get_user(c,p++);
	197	} while (c);
	198	}
	199	put_user(NULL,envp);
	200	current->mm->env_end = (unsigned long) p;
	201	return sp;
	202	}
	203
	204	/*
	205	* These are the functions used to load a.out style executables and shared
	206	* libraries. There is no binary dependent code anywhere else.
	207	*/
	208
	209	static int load_aout_binary(struct linux_binprm * bprm, struct pt_regs * regs)
	210	{
	211	struct exec ex;
	212	unsigned long error;
	213	unsigned long fd_offset;
	214	unsigned long rlim;
	215	int retval;
	216
	217	ex = ((struct exec ) bprm->buf); /* exec-header */
	218	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != OMAGIC &&
	219	N_MAGIC(ex) != QMAGIC && N_MAGIC(ex) != NMAGIC) \|\|
	220	N_TRSIZE(ex) \|\| N_DRSIZE(ex) \|\|
0f7fc9e4	221	i_size_read(bprm->file->f_path.dentry->d_inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
1da177e4 LT	222	return -ENOEXEC;
	223	}
	224
8454aeef ET	225	/*
	226	* Requires a mmap handler. This prevents people from using a.out
	227	* as part of an exploit attack against /proc-related vulnerabilities.
	228	*/
	229	if (!bprm->file->f_op \|\| !bprm->file->f_op->mmap)
	230	return -ENOEXEC;
	231
1da177e4 LT	232	fd_offset = N_TXTOFF(ex);
	233
	234	/* Check initial limits. This avoids letting people circumvent
	235	* size limits imposed on them by creating programs with large
	236	* arrays in the data or bss.
	237	*/
d554ed89	238	rlim = rlimit(RLIMIT_DATA);
1da177e4 LT	239	if (rlim >= RLIM_INFINITY)
	240	rlim = ~0;
	241	if (ex.a_data + ex.a_bss > rlim)
	242	return -ENOMEM;
	243
	244	/* Flush all traces of the currently running executable */
	245	retval = flush_old_exec(bprm);
	246	if (retval)
	247	return retval;
	248
	249	/* OK, This is the point of no return */
17580d7f	250	#ifdef __alpha__
1da177e4	251	SET_AOUT_PERSONALITY(bprm, ex);
1da177e4 LT	252	#else
	253	set_personality(PER_LINUX);
	254	#endif
221af7f8	255	setup_new_exec(bprm);
1da177e4 LT	256
	257	current->mm->end_code = ex.a_text +
	258	(current->mm->start_code = N_TXTADDR(ex));
	259	current->mm->end_data = ex.a_data +
	260	(current->mm->start_data = N_DATADDR(ex));
	261	current->mm->brk = ex.a_bss +
	262	(current->mm->start_brk = N_BSSADDR(ex));
	263	current->mm->free_area_cache = current->mm->mmap_base;
1363c3cd	264	current->mm->cached_hole_size = 0;
1da177e4	265
a6f76f23	266	install_exec_creds(bprm);
1da177e4	267	current->flags &= ~PF_FORKNOEXEC;
1da177e4 LT	268
	269	if (N_MAGIC(ex) == OMAGIC) {
	270	unsigned long text_addr, map_size;
	271	loff_t pos;
	272
	273	text_addr = N_TXTADDR(ex);
	274
fe30af97	275	#ifdef __alpha__
1da177e4 LT	276	pos = fd_offset;
	277	map_size = ex.a_text+ex.a_data + PAGE_SIZE - 1;
	278	#else
	279	pos = 32;
	280	map_size = ex.a_text+ex.a_data;
	281	#endif
	282	down_write(&current->mm->mmap_sem);
	283	error = do_brk(text_addr & PAGE_MASK, map_size);
	284	up_write(&current->mm->mmap_sem);
	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;
	315	down_write(&current->mm->mmap_sem);
	316	do_brk(N_TXTADDR(ex), ex.a_text+ex.a_data);
	317	up_write(&current->mm->mmap_sem);
	318	bprm->file->f_op->read(bprm->file,
	319	(char __user *)N_TXTADDR(ex),
	320	ex.a_text+ex.a_data, &pos);
	321	flush_icache_range((unsigned long) N_TXTADDR(ex),
	322	(unsigned long) N_TXTADDR(ex) +
	323	ex.a_text+ex.a_data);
	324	goto beyond_if;
	325	}
	326
	327	down_write(&current->mm->mmap_sem);
	328	error = do_mmap(bprm->file, N_TXTADDR(ex), ex.a_text,
	329	PROT_READ \| PROT_EXEC,
	330	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	331	fd_offset);
	332	up_write(&current->mm->mmap_sem);
	333
	334	if (error != N_TXTADDR(ex)) {
	335	send_sig(SIGKILL, current, 0);
	336	return error;
	337	}
	338
	339	down_write(&current->mm->mmap_sem);
	340	error = do_mmap(bprm->file, N_DATADDR(ex), ex.a_data,
	341	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	342	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE \| MAP_EXECUTABLE,
	343	fd_offset + ex.a_text);
	344	up_write(&current->mm->mmap_sem);
	345	if (error != N_DATADDR(ex)) {
	346	send_sig(SIGKILL, current, 0);
	347	return error;
	348	}
	349	}
	350	beyond_if:
	351	set_binfmt(&aout_format);
	352
	353	retval = set_brk(current->mm->start_brk, current->mm->brk);
	354	if (retval < 0) {
	355	send_sig(SIGKILL, current, 0);
	356	return retval;
	357	}
	358
	359	retval = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
	360	if (retval < 0) {
	361	/* Someone check-me: is this error path enough? */
	362	send_sig(SIGKILL, current, 0);
	363	return retval;
	364	}
	365
	366	current->mm->start_stack =
	367	(unsigned long) create_aout_tables((char __user *) bprm->p, bprm);
	368	#ifdef __alpha__
	369	regs->gp = ex.a_gpvalue;
	370	#endif
	371	start_thread(regs, ex.a_entry, current->mm->start_stack);
1da177e4 LT	372	return 0;
	373	}
	374
	375	static int load_aout_library(struct file *file)
	376	{
	377	struct inode * inode;
	378	unsigned long bss, start_addr, len;
	379	unsigned long error;
	380	int retval;
	381	struct exec ex;
	382
0f7fc9e4	383	inode = file->f_path.dentry->d_inode;
1da177e4 LT	384
	385	retval = -ENOEXEC;
	386	error = kernel_read(file, 0, (char *) &ex, sizeof(ex));
	387	if (error != sizeof(ex))
	388	goto out;
	389
	390	/* We come in here for the regular a.out style of shared libraries */
	391	if ((N_MAGIC(ex) != ZMAGIC && N_MAGIC(ex) != QMAGIC) \|\| N_TRSIZE(ex) \|\|
	392	N_DRSIZE(ex) \|\| ((ex.a_entry & 0xfff) && N_MAGIC(ex) == ZMAGIC) \|\|
	393	i_size_read(inode) < ex.a_text+ex.a_data+N_SYMSIZE(ex)+N_TXTOFF(ex)) {
	394	goto out;
	395	}
	396
8454aeef ET	397	/*
	398	* Requires a mmap handler. This prevents people from using a.out
	399	* as part of an exploit attack against /proc-related vulnerabilities.
	400	*/
	401	if (!file->f_op \|\| !file->f_op->mmap)
	402	goto out;
	403
1da177e4 LT	404	if (N_FLAGS(ex))
	405	goto out;
	406
	407	/* For QMAGIC, the starting address is 0x20 into the page. We mask
	408	this off to get the starting address for the page */
	409
	410	start_addr = ex.a_entry & 0xfffff000;
	411
	412	if ((N_TXTOFF(ex) & ~PAGE_MASK) != 0) {
1da177e4 LT	413	loff_t pos = N_TXTOFF(ex);
1da177e4 LT	414
2e50b6cc	415	if (printk_ratelimit())
1da177e4 LT	416	{
	417	printk(KERN_WARNING
	418	"N_TXTOFF is not page aligned. Please convert library: %s\n",
0f7fc9e4	419	file->f_path.dentry->d_name.name);
1da177e4 LT	420	}
	421	down_write(&current->mm->mmap_sem);
	422	do_brk(start_addr, ex.a_text + ex.a_data + ex.a_bss);
	423	up_write(&current->mm->mmap_sem);
	424
	425	file->f_op->read(file, (char __user *)start_addr,
	426	ex.a_text + ex.a_data, &pos);
	427	flush_icache_range((unsigned long) start_addr,
	428	(unsigned long) start_addr + ex.a_text + ex.a_data);
	429
	430	retval = 0;
	431	goto out;
	432	}
	433	/* Now use mmap to map the library into memory. */
	434	down_write(&current->mm->mmap_sem);
	435	error = do_mmap(file, start_addr, ex.a_text + ex.a_data,
	436	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	437	MAP_FIXED \| MAP_PRIVATE \| MAP_DENYWRITE,
	438	N_TXTOFF(ex));
	439	up_write(&current->mm->mmap_sem);
	440	retval = error;
	441	if (error != start_addr)
	442	goto out;
	443
	444	len = PAGE_ALIGN(ex.a_text + ex.a_data);
	445	bss = ex.a_text + ex.a_data + ex.a_bss;
	446	if (bss > len) {
	447	down_write(&current->mm->mmap_sem);
	448	error = do_brk(start_addr + len, bss - len);
	449	up_write(&current->mm->mmap_sem);
	450	retval = error;
	451	if (error != start_addr + len)
	452	goto out;
	453	}
	454	retval = 0;
	455	out:
	456	return retval;
	457	}
	458
	459	static int __init init_aout_binfmt(void)
	460	{
	461	return register_binfmt(&aout_format);
	462	}
	463
	464	static void __exit exit_aout_binfmt(void)
	465	{
	466	unregister_binfmt(&aout_format);
	467	}
	468
	469	core_initcall(init_aout_binfmt);
	470	module_exit(exit_aout_binfmt);
	471	MODULE_LICENSE("GPL");