blob: 614991bf0c8738c616e342a51251ad378ff790a3 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/exec.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7/*
8 * #!-checking implemented by tytso.
9 */
10/*
11 * Demand-loading implemented 01.12.91 - no need to read anything but
12 * the header into memory. The inode of the executable is put into
13 * "current->executable", and page faults do the actual loading. Clean.
14 *
15 * Once more I can proudly say that linux stood up to being changed: it
16 * was less than 2 hours work to get demand-loading completely implemented.
17 *
18 * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead,
19 * current->executable is only used by the procfs. This allows a dispatch
20 * table to check for several different types of binary formats. We keep
21 * trying until we recognize the file or we run out of supported binary
22 * formats.
23 */
24
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/slab.h>
26#include <linux/file.h>
Al Viro9f3acc32008-04-24 07:44:08 -040027#include <linux/fdtable.h>
Hugh Dickinsba92a432008-07-25 01:45:43 -070028#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/stat.h>
30#include <linux/fcntl.h>
31#include <linux/smp_lock.h>
Hugh Dickinsba92a432008-07-25 01:45:43 -070032#include <linux/swap.h>
Neil Horman74aadce2007-10-16 23:26:35 -070033#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/init.h>
Hugh Dickinsca5b1722008-07-28 15:46:18 -070035#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <linux/highmem.h>
37#include <linux/spinlock.h>
38#include <linux/key.h>
39#include <linux/personality.h>
40#include <linux/binfmts.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <linux/utsname.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080042#include <linux/pid_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <linux/module.h>
44#include <linux/namei.h>
45#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/mount.h>
47#include <linux/security.h>
Mimi Zohar6146f0d2009-02-04 09:06:57 -050048#include <linux/ima.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/syscalls.h>
Jay Lan8f0ab512006-09-30 23:28:59 -070050#include <linux/tsacct_kern.h>
Matt Helsley9f460802005-11-07 00:59:16 -080051#include <linux/cn_proc.h>
Al Viro473ae302006-04-26 14:04:08 -040052#include <linux/audit.h>
Roland McGrath6341c392008-07-25 19:45:44 -070053#include <linux/tracehook.h>
Johannes Berg5f4123b2008-07-09 10:28:40 +020054#include <linux/kmod.h>
Eric Paris6110e3a2008-12-17 13:53:20 -050055#include <linux/fsnotify.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57#include <asm/uaccess.h>
58#include <asm/mmu_context.h>
Ollie Wildb6a2fea2007-07-19 01:48:16 -070059#include <asm/tlb.h>
David Howellsa6f76f22008-11-14 10:39:24 +110060#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
Linus Torvalds1da177e2005-04-16 15:20:36 -070062int core_uses_pid;
Dan Aloni71ce92f2007-05-16 22:11:16 -070063char core_pattern[CORENAME_MAX_SIZE] = "core";
Alan Coxd6e71142005-06-23 00:09:43 -070064int suid_dumpable = 0;
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066/* The maximal length of core_pattern is also specified in sysctl.c */
67
Alexey Dobriyane4dc1b12007-10-16 23:26:03 -070068static LIST_HEAD(formats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069static DEFINE_RWLOCK(binfmt_lock);
70
71int register_binfmt(struct linux_binfmt * fmt)
72{
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 if (!fmt)
74 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 write_lock(&binfmt_lock);
Alexey Dobriyane4dc1b12007-10-16 23:26:03 -070076 list_add(&fmt->lh, &formats);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 write_unlock(&binfmt_lock);
78 return 0;
79}
80
81EXPORT_SYMBOL(register_binfmt);
82
Alexey Dobriyanf6b450d2007-10-16 23:26:04 -070083void unregister_binfmt(struct linux_binfmt * fmt)
Linus Torvalds1da177e2005-04-16 15:20:36 -070084{
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 write_lock(&binfmt_lock);
Alexey Dobriyane4dc1b12007-10-16 23:26:03 -070086 list_del(&fmt->lh);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 write_unlock(&binfmt_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088}
89
90EXPORT_SYMBOL(unregister_binfmt);
91
92static inline void put_binfmt(struct linux_binfmt * fmt)
93{
94 module_put(fmt->module);
95}
96
97/*
98 * Note that a shared library must be both readable and executable due to
99 * security reasons.
100 *
101 * Also note that we take the address to load from from the file itself.
102 */
Heiko Carstens1e7bfb22009-01-14 14:14:29 +0100103SYSCALL_DEFINE1(uselib, const char __user *, library)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104{
Al Viro964bd182008-07-26 03:33:14 -0400105 struct file *file;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 struct nameidata nd;
Al Viro964bd182008-07-26 03:33:14 -0400107 char *tmp = getname(library);
108 int error = PTR_ERR(tmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109
Al Viro964bd182008-07-26 03:33:14 -0400110 if (!IS_ERR(tmp)) {
111 error = path_lookup_open(AT_FDCWD, tmp,
112 LOOKUP_FOLLOW, &nd,
113 FMODE_READ|FMODE_EXEC);
114 putname(tmp);
115 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 if (error)
117 goto out;
118
119 error = -EINVAL;
Jan Blunck4ac91372008-02-14 19:34:32 -0800120 if (!S_ISREG(nd.path.dentry->d_inode->i_mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 goto exit;
122
Al Viro30524472008-07-22 00:02:33 -0400123 error = -EACCES;
124 if (nd.path.mnt->mnt_flags & MNT_NOEXEC)
125 goto exit;
126
Christoph Hellwigcb23beb2008-10-24 09:59:29 +0200127 error = inode_permission(nd.path.dentry->d_inode,
128 MAY_READ | MAY_EXEC | MAY_OPEN);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 if (error)
130 goto exit;
Mimi Zohar6146f0d2009-02-04 09:06:57 -0500131 error = ima_path_check(&nd.path, MAY_READ | MAY_EXEC | MAY_OPEN);
132 if (error)
133 goto exit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Andi Kleenabe8be32008-02-08 04:20:23 -0800135 file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 error = PTR_ERR(file);
137 if (IS_ERR(file))
138 goto out;
139
Eric Paris6110e3a2008-12-17 13:53:20 -0500140 fsnotify_open(file->f_path.dentry);
141
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 error = -ENOEXEC;
143 if(file->f_op) {
144 struct linux_binfmt * fmt;
145
146 read_lock(&binfmt_lock);
Alexey Dobriyane4dc1b12007-10-16 23:26:03 -0700147 list_for_each_entry(fmt, &formats, lh) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 if (!fmt->load_shlib)
149 continue;
150 if (!try_module_get(fmt->module))
151 continue;
152 read_unlock(&binfmt_lock);
153 error = fmt->load_shlib(file);
154 read_lock(&binfmt_lock);
155 put_binfmt(fmt);
156 if (error != -ENOEXEC)
157 break;
158 }
159 read_unlock(&binfmt_lock);
160 }
161 fput(file);
162out:
163 return error;
164exit:
Trond Myklebust834f2a42005-10-18 14:20:16 -0700165 release_open_intent(&nd);
Jan Blunck1d957f92008-02-14 19:34:35 -0800166 path_put(&nd.path);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 goto out;
168}
169
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700170#ifdef CONFIG_MMU
171
172static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
173 int write)
174{
175 struct page *page;
176 int ret;
177
178#ifdef CONFIG_STACK_GROWSUP
179 if (write) {
180 ret = expand_stack_downwards(bprm->vma, pos);
181 if (ret < 0)
182 return NULL;
183 }
184#endif
185 ret = get_user_pages(current, bprm->mm, pos,
186 1, write, 1, &page, NULL);
187 if (ret <= 0)
188 return NULL;
189
190 if (write) {
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700191 unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start;
Linus Torvaldsa64e7152008-03-03 10:12:14 -0800192 struct rlimit *rlim;
193
194 /*
195 * We've historically supported up to 32 pages (ARG_MAX)
196 * of argument strings even with small stacks
197 */
198 if (size <= ARG_MAX)
199 return page;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700200
201 /*
202 * Limit to 1/4-th the stack size for the argv+env strings.
203 * This ensures that:
204 * - the remaining binfmt code will not run out of stack space,
205 * - the program will have a reasonable amount of stack left
206 * to work from.
207 */
Linus Torvaldsa64e7152008-03-03 10:12:14 -0800208 rlim = current->signal->rlim;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700209 if (size > rlim[RLIMIT_STACK].rlim_cur / 4) {
210 put_page(page);
211 return NULL;
212 }
213 }
214
215 return page;
216}
217
218static void put_arg_page(struct page *page)
219{
220 put_page(page);
221}
222
223static void free_arg_page(struct linux_binprm *bprm, int i)
224{
225}
226
227static void free_arg_pages(struct linux_binprm *bprm)
228{
229}
230
231static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
232 struct page *page)
233{
234 flush_cache_page(bprm->vma, pos, page_to_pfn(page));
235}
236
237static int __bprm_mm_init(struct linux_binprm *bprm)
238{
Luiz Fernando N. Capitulinoeaccbfa2009-01-06 14:40:44 -0800239 int err;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700240 struct vm_area_struct *vma = NULL;
241 struct mm_struct *mm = bprm->mm;
242
243 bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
244 if (!vma)
Luiz Fernando N. Capitulinoeaccbfa2009-01-06 14:40:44 -0800245 return -ENOMEM;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700246
247 down_write(&mm->mmap_sem);
248 vma->vm_mm = mm;
249
250 /*
251 * Place the stack at the largest stack address the architecture
252 * supports. Later, we'll move this to an appropriate place. We don't
253 * use STACK_TOP because that can depend on attributes which aren't
254 * configured yet.
255 */
256 vma->vm_end = STACK_TOP_MAX;
257 vma->vm_start = vma->vm_end - PAGE_SIZE;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700258 vma->vm_flags = VM_STACK_FLAGS;
Coly Li3ed75eb2007-10-18 23:39:15 -0700259 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700260 err = insert_vm_struct(mm, vma);
Luiz Fernando N. Capitulinoeaccbfa2009-01-06 14:40:44 -0800261 if (err)
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700262 goto err;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700263
264 mm->stack_vm = mm->total_vm = 1;
265 up_write(&mm->mmap_sem);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700266 bprm->p = vma->vm_end - sizeof(void *);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700267 return 0;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700268err:
Luiz Fernando N. Capitulinoeaccbfa2009-01-06 14:40:44 -0800269 up_write(&mm->mmap_sem);
270 bprm->vma = NULL;
271 kmem_cache_free(vm_area_cachep, vma);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700272 return err;
273}
274
275static bool valid_arg_len(struct linux_binprm *bprm, long len)
276{
277 return len <= MAX_ARG_STRLEN;
278}
279
280#else
281
282static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
283 int write)
284{
285 struct page *page;
286
287 page = bprm->page[pos / PAGE_SIZE];
288 if (!page && write) {
289 page = alloc_page(GFP_HIGHUSER|__GFP_ZERO);
290 if (!page)
291 return NULL;
292 bprm->page[pos / PAGE_SIZE] = page;
293 }
294
295 return page;
296}
297
298static void put_arg_page(struct page *page)
299{
300}
301
302static void free_arg_page(struct linux_binprm *bprm, int i)
303{
304 if (bprm->page[i]) {
305 __free_page(bprm->page[i]);
306 bprm->page[i] = NULL;
307 }
308}
309
310static void free_arg_pages(struct linux_binprm *bprm)
311{
312 int i;
313
314 for (i = 0; i < MAX_ARG_PAGES; i++)
315 free_arg_page(bprm, i);
316}
317
318static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
319 struct page *page)
320{
321}
322
323static int __bprm_mm_init(struct linux_binprm *bprm)
324{
325 bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);
326 return 0;
327}
328
329static bool valid_arg_len(struct linux_binprm *bprm, long len)
330{
331 return len <= bprm->p;
332}
333
334#endif /* CONFIG_MMU */
335
336/*
337 * Create a new mm_struct and populate it with a temporary stack
338 * vm_area_struct. We don't have enough context at this point to set the stack
339 * flags, permissions, and offset, so we use temporary values. We'll update
340 * them later in setup_arg_pages().
341 */
342int bprm_mm_init(struct linux_binprm *bprm)
343{
344 int err;
345 struct mm_struct *mm = NULL;
346
347 bprm->mm = mm = mm_alloc();
348 err = -ENOMEM;
349 if (!mm)
350 goto err;
351
352 err = init_new_context(current, mm);
353 if (err)
354 goto err;
355
356 err = __bprm_mm_init(bprm);
357 if (err)
358 goto err;
359
360 return 0;
361
362err:
363 if (mm) {
364 bprm->mm = NULL;
365 mmdrop(mm);
366 }
367
368 return err;
369}
370
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371/*
372 * count() counts the number of strings in array ARGV.
373 */
374static int count(char __user * __user * argv, int max)
375{
376 int i = 0;
377
378 if (argv != NULL) {
379 for (;;) {
380 char __user * p;
381
382 if (get_user(p, argv))
383 return -EFAULT;
384 if (!p)
385 break;
386 argv++;
Jason Baron362e6662008-10-15 22:01:52 -0700387 if (i++ >= max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 return -E2BIG;
389 cond_resched();
390 }
391 }
392 return i;
393}
394
395/*
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700396 * 'copy_strings()' copies argument/environment strings from the old
397 * processes's memory to the new process's stack. The call to get_user_pages()
398 * ensures the destination page is created and not swapped out.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 */
Adrian Bunk75c96f82005-05-05 16:16:09 -0700400static int copy_strings(int argc, char __user * __user * argv,
401 struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402{
403 struct page *kmapped_page = NULL;
404 char *kaddr = NULL;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700405 unsigned long kpos = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 int ret;
407
408 while (argc-- > 0) {
409 char __user *str;
410 int len;
411 unsigned long pos;
412
413 if (get_user(str, argv+argc) ||
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700414 !(len = strnlen_user(str, MAX_ARG_STRLEN))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 ret = -EFAULT;
416 goto out;
417 }
418
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700419 if (!valid_arg_len(bprm, len)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 ret = -E2BIG;
421 goto out;
422 }
423
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700424 /* We're going to work our way backwords. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 pos = bprm->p;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700426 str += len;
427 bprm->p -= len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
429 while (len > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 int offset, bytes_to_copy;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
432 offset = pos % PAGE_SIZE;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700433 if (offset == 0)
434 offset = PAGE_SIZE;
435
436 bytes_to_copy = offset;
437 if (bytes_to_copy > len)
438 bytes_to_copy = len;
439
440 offset -= bytes_to_copy;
441 pos -= bytes_to_copy;
442 str -= bytes_to_copy;
443 len -= bytes_to_copy;
444
445 if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
446 struct page *page;
447
448 page = get_arg_page(bprm, pos, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 if (!page) {
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700450 ret = -E2BIG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 goto out;
452 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700454 if (kmapped_page) {
455 flush_kernel_dcache_page(kmapped_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 kunmap(kmapped_page);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700457 put_arg_page(kmapped_page);
458 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 kmapped_page = page;
460 kaddr = kmap(kmapped_page);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700461 kpos = pos & PAGE_MASK;
462 flush_arg_page(bprm, kpos, kmapped_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 }
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700464 if (copy_from_user(kaddr+offset, str, bytes_to_copy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 ret = -EFAULT;
466 goto out;
467 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 }
469 }
470 ret = 0;
471out:
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700472 if (kmapped_page) {
473 flush_kernel_dcache_page(kmapped_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 kunmap(kmapped_page);
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700475 put_arg_page(kmapped_page);
476 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 return ret;
478}
479
480/*
481 * Like copy_strings, but get argv and its values from kernel memory.
482 */
483int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
484{
485 int r;
486 mm_segment_t oldfs = get_fs();
487 set_fs(KERNEL_DS);
488 r = copy_strings(argc, (char __user * __user *)argv, bprm);
489 set_fs(oldfs);
490 return r;
491}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492EXPORT_SYMBOL(copy_strings_kernel);
493
494#ifdef CONFIG_MMU
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700495
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496/*
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700497 * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once
498 * the binfmt code determines where the new stack should reside, we shift it to
499 * its final location. The process proceeds as follows:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 *
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700501 * 1) Use shift to calculate the new vma endpoints.
502 * 2) Extend vma to cover both the old and new ranges. This ensures the
503 * arguments passed to subsequent functions are consistent.
504 * 3) Move vma's page tables to the new range.
505 * 4) Free up any cleared pgd range.
506 * 5) Shrink the vma to cover only the new range.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 */
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700508static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509{
510 struct mm_struct *mm = vma->vm_mm;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700511 unsigned long old_start = vma->vm_start;
512 unsigned long old_end = vma->vm_end;
513 unsigned long length = old_end - old_start;
514 unsigned long new_start = old_start - shift;
515 unsigned long new_end = old_end - shift;
516 struct mmu_gather *tlb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700518 BUG_ON(new_start > new_end);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700520 /*
521 * ensure there are no vmas between where we want to go
522 * and where we are
523 */
524 if (vma != find_vma(mm, new_start))
525 return -EFAULT;
526
527 /*
528 * cover the whole range: [new_start, old_end)
529 */
530 vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL);
531
532 /*
533 * move the page tables downwards, on failure we rely on
534 * process cleanup to remove whatever mess we made.
535 */
536 if (length != move_page_tables(vma, old_start,
537 vma, new_start, length))
538 return -ENOMEM;
539
540 lru_add_drain();
541 tlb = tlb_gather_mmu(mm, 0);
542 if (new_end > old_start) {
543 /*
544 * when the old and new regions overlap clear from new_end.
545 */
Jan Beulich42b77722008-07-23 21:27:10 -0700546 free_pgd_range(tlb, new_end, old_end, new_end,
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700547 vma->vm_next ? vma->vm_next->vm_start : 0);
548 } else {
549 /*
550 * otherwise, clean from old_start; this is done to not touch
551 * the address space in [new_end, old_start) some architectures
552 * have constraints on va-space that make this illegal (IA64) -
553 * for the others its just a little faster.
554 */
Jan Beulich42b77722008-07-23 21:27:10 -0700555 free_pgd_range(tlb, old_start, old_end, new_end,
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700556 vma->vm_next ? vma->vm_next->vm_start : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 }
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700558 tlb_finish_mmu(tlb, new_end, old_end);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700560 /*
561 * shrink the vma to just the new range.
562 */
563 vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL);
564
565 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566}
567
568#define EXTRA_STACK_VM_PAGES 20 /* random */
569
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700570/*
571 * Finalizes the stack vm_area_struct. The flags and permissions are updated,
572 * the stack is optionally relocated, and some extra space is added.
573 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574int setup_arg_pages(struct linux_binprm *bprm,
575 unsigned long stack_top,
576 int executable_stack)
577{
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700578 unsigned long ret;
579 unsigned long stack_shift;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 struct mm_struct *mm = current->mm;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700581 struct vm_area_struct *vma = bprm->vma;
582 struct vm_area_struct *prev = NULL;
583 unsigned long vm_flags;
584 unsigned long stack_base;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586#ifdef CONFIG_STACK_GROWSUP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 /* Limit stack size to 1GB */
588 stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max;
589 if (stack_base > (1 << 30))
590 stack_base = 1 << 30;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700592 /* Make sure we didn't let the argument array grow too large. */
593 if (vma->vm_end - vma->vm_start > stack_base)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 return -ENOMEM;
595
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700596 stack_base = PAGE_ALIGN(stack_top - stack_base);
597
598 stack_shift = vma->vm_start - stack_base;
599 mm->arg_start = bprm->p - stack_shift;
600 bprm->p = vma->vm_end - stack_shift;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601#else
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700602 stack_top = arch_align_stack(stack_top);
603 stack_top = PAGE_ALIGN(stack_top);
604 stack_shift = vma->vm_end - stack_top;
605
606 bprm->p -= stack_shift;
607 mm->arg_start = bprm->p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608#endif
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700609
610 if (bprm->loader)
611 bprm->loader -= stack_shift;
612 bprm->exec -= stack_shift;
613
614 down_write(&mm->mmap_sem);
Hugh Dickins96a8e132008-07-10 21:19:20 +0100615 vm_flags = VM_STACK_FLAGS;
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700616
617 /*
618 * Adjust stack execute permissions; explicitly enable for
619 * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone
620 * (arch default) otherwise.
621 */
622 if (unlikely(executable_stack == EXSTACK_ENABLE_X))
623 vm_flags |= VM_EXEC;
624 else if (executable_stack == EXSTACK_DISABLE_X)
625 vm_flags &= ~VM_EXEC;
626 vm_flags |= mm->def_flags;
627
628 ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end,
629 vm_flags);
630 if (ret)
631 goto out_unlock;
632 BUG_ON(prev != vma);
633
634 /* Move stack pages down in memory. */
635 if (stack_shift) {
636 ret = shift_arg_pages(vma, stack_shift);
637 if (ret) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 up_write(&mm->mmap_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 return ret;
640 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 }
642
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700643#ifdef CONFIG_STACK_GROWSUP
644 stack_base = vma->vm_end + EXTRA_STACK_VM_PAGES * PAGE_SIZE;
645#else
646 stack_base = vma->vm_start - EXTRA_STACK_VM_PAGES * PAGE_SIZE;
647#endif
648 ret = expand_stack(vma, stack_base);
649 if (ret)
650 ret = -EFAULT;
651
652out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 up_write(&mm->mmap_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 return 0;
655}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656EXPORT_SYMBOL(setup_arg_pages);
657
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658#endif /* CONFIG_MMU */
659
660struct file *open_exec(const char *name)
661{
662 struct nameidata nd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 struct file *file;
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200664 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200666 err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd,
667 FMODE_READ|FMODE_EXEC);
668 if (err)
669 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200671 err = -EACCES;
672 if (!S_ISREG(nd.path.dentry->d_inode->i_mode))
673 goto out_path_put;
674
Al Viro30524472008-07-22 00:02:33 -0400675 if (nd.path.mnt->mnt_flags & MNT_NOEXEC)
676 goto out_path_put;
677
Christoph Hellwigcb23beb2008-10-24 09:59:29 +0200678 err = inode_permission(nd.path.dentry->d_inode, MAY_EXEC | MAY_OPEN);
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200679 if (err)
680 goto out_path_put;
Mimi Zohar6146f0d2009-02-04 09:06:57 -0500681 err = ima_path_check(&nd.path, MAY_EXEC | MAY_OPEN);
682 if (err)
683 goto out_path_put;
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200684
685 file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
686 if (IS_ERR(file))
687 return file;
688
Eric Paris6110e3a2008-12-17 13:53:20 -0500689 fsnotify_open(file->f_path.dentry);
690
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200691 err = deny_write_access(file);
692 if (err) {
693 fput(file);
694 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696
Christoph Hellwige56b6a52008-05-19 07:53:34 +0200697 return file;
698
699 out_path_put:
700 release_open_intent(&nd);
701 path_put(&nd.path);
702 out:
703 return ERR_PTR(err);
704}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705EXPORT_SYMBOL(open_exec);
706
707int kernel_read(struct file *file, unsigned long offset,
708 char *addr, unsigned long count)
709{
710 mm_segment_t old_fs;
711 loff_t pos = offset;
712 int result;
713
714 old_fs = get_fs();
715 set_fs(get_ds());
716 /* The cast to a user pointer is valid due to the set_fs() */
717 result = vfs_read(file, (void __user *)addr, count, &pos);
718 set_fs(old_fs);
719 return result;
720}
721
722EXPORT_SYMBOL(kernel_read);
723
724static int exec_mmap(struct mm_struct *mm)
725{
726 struct task_struct *tsk;
727 struct mm_struct * old_mm, *active_mm;
728
729 /* Notify parent that we're no longer interested in the old VM */
730 tsk = current;
731 old_mm = current->mm;
732 mm_release(tsk, old_mm);
733
734 if (old_mm) {
735 /*
736 * Make sure that if there is a core dump in progress
737 * for the old mm, we get out and die instead of going
738 * through with the exec. We must hold mmap_sem around
Oleg Nesterov999d9fc2008-07-25 01:47:41 -0700739 * checking core_state and changing tsk->mm.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 */
741 down_read(&old_mm->mmap_sem);
Oleg Nesterov999d9fc2008-07-25 01:47:41 -0700742 if (unlikely(old_mm->core_state)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 up_read(&old_mm->mmap_sem);
744 return -EINTR;
745 }
746 }
747 task_lock(tsk);
748 active_mm = tsk->active_mm;
749 tsk->mm = mm;
750 tsk->active_mm = mm;
751 activate_mm(active_mm, mm);
752 task_unlock(tsk);
753 arch_pick_mmap_layout(mm);
754 if (old_mm) {
755 up_read(&old_mm->mmap_sem);
Eric Sesterhenn7dddb122006-04-01 01:13:38 +0200756 BUG_ON(active_mm != old_mm);
Balbir Singh31a78f22008-09-28 23:09:31 +0100757 mm_update_next_owner(old_mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 mmput(old_mm);
759 return 0;
760 }
761 mmdrop(active_mm);
762 return 0;
763}
764
765/*
766 * This function makes sure the current process has its own signal table,
767 * so that flush_signal_handlers can later reset the handlers without
768 * disturbing other processes. (Other processes might share the signal
769 * table via the CLONE_SIGHAND option to clone().)
770 */
Arjan van de Ven858119e2006-01-14 13:20:43 -0800771static int de_thread(struct task_struct *tsk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772{
773 struct signal_struct *sig = tsk->signal;
Oleg Nesterovb2c903b2007-10-16 23:27:22 -0700774 struct sighand_struct *oldsighand = tsk->sighand;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 spinlock_t *lock = &oldsighand->siglock;
776 int count;
777
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700778 if (thread_group_empty(tsk))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 goto no_thread_group;
780
781 /*
782 * Kill all other threads in the thread group.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 spin_lock_irq(lock);
Oleg Nesteroved5d2ca2008-02-04 22:27:24 -0800785 if (signal_group_exit(sig)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 /*
787 * Another group action in progress, just
788 * return so that the signal is processed.
789 */
790 spin_unlock_irq(lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 return -EAGAIN;
792 }
Oleg Nesteroved5d2ca2008-02-04 22:27:24 -0800793 sig->group_exit_task = tsk;
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700794 zap_other_threads(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795
Oleg Nesterovfea9d172008-02-08 04:19:19 -0800796 /* Account for the thread group leader hanging around: */
797 count = thread_group_leader(tsk) ? 1 : 2;
Oleg Nesterov6db840f2007-10-16 23:27:23 -0700798 sig->notify_count = count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 while (atomic_read(&sig->count) > count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 __set_current_state(TASK_UNINTERRUPTIBLE);
801 spin_unlock_irq(lock);
802 schedule();
803 spin_lock_irq(lock);
804 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 spin_unlock_irq(lock);
806
807 /*
808 * At this point all other threads have exited, all we have to
809 * do is to wait for the thread group leader to become inactive,
810 * and to assume its PID:
811 */
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700812 if (!thread_group_leader(tsk)) {
Oleg Nesterov81879262008-12-01 14:18:16 -0800813 struct task_struct *leader = tsk->group_leader;
Oleg Nesterov6db840f2007-10-16 23:27:23 -0700814
Oleg Nesterov2800d8d2008-04-30 00:53:12 -0700815 sig->notify_count = -1; /* for exit_notify() */
Oleg Nesterov6db840f2007-10-16 23:27:23 -0700816 for (;;) {
817 write_lock_irq(&tasklist_lock);
818 if (likely(leader->exit_state))
819 break;
820 __set_current_state(TASK_UNINTERRUPTIBLE);
821 write_unlock_irq(&tasklist_lock);
822 schedule();
823 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
Roland McGrathf5e90282006-04-10 22:54:16 -0700825 /*
826 * The only record we have of the real-time age of a
827 * process, regardless of execs it's done, is start_time.
828 * All the past CPU time is accumulated in signal_struct
829 * from sister threads now dead. But in this non-leader
830 * exec, nothing survives from the original leader thread,
831 * whose birth marks the true age of this process now.
832 * When we take on its identity by switching to its PID, we
833 * also take its birthdate (always earlier than our own).
834 */
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700835 tsk->start_time = leader->start_time;
Roland McGrathf5e90282006-04-10 22:54:16 -0700836
Pavel Emelyanovbac0abd2007-10-18 23:40:18 -0700837 BUG_ON(!same_thread_group(leader, tsk));
838 BUG_ON(has_group_leader_pid(tsk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 /*
840 * An exec() starts a new thread group with the
841 * TGID of the previous thread group. Rehash the
842 * two threads with a switched PID, and release
843 * the former thread group leader:
844 */
Eric W. Biedermand73d6522006-03-28 16:11:03 -0800845
846 /* Become a process group leader with the old leader's pid.
Eric W. Biedermanc18258c2006-09-27 01:51:06 -0700847 * The old leader becomes a thread of the this thread group.
848 * Note: The old leader also uses this pid until release_task
Eric W. Biedermand73d6522006-03-28 16:11:03 -0800849 * is called. Odd but simple and correct.
850 */
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700851 detach_pid(tsk, PIDTYPE_PID);
852 tsk->pid = leader->pid;
Sukadev Bhattiprolu3743ca02007-10-18 23:39:51 -0700853 attach_pid(tsk, PIDTYPE_PID, task_pid(leader));
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700854 transfer_pid(leader, tsk, PIDTYPE_PGID);
855 transfer_pid(leader, tsk, PIDTYPE_SID);
856 list_replace_rcu(&leader->tasks, &tsk->tasks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700858 tsk->group_leader = tsk;
859 leader->group_leader = tsk;
Eric W. Biedermande12a782006-04-10 17:16:49 -0600860
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700861 tsk->exit_signal = SIGCHLD;
Oleg Nesterov962b5642005-11-23 13:37:43 -0800862
863 BUG_ON(leader->exit_state != EXIT_ZOMBIE);
864 leader->exit_state = EXIT_DEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 write_unlock_irq(&tasklist_lock);
Oleg Nesterov81879262008-12-01 14:18:16 -0800866
867 release_task(leader);
Oleg Nesteroved5d2ca2008-02-04 22:27:24 -0800868 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
Oleg Nesterov6db840f2007-10-16 23:27:23 -0700870 sig->group_exit_task = NULL;
871 sig->notify_count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872
873no_thread_group:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 exit_itimers(sig);
Oleg Nesterovcbaffba2008-05-26 20:55:42 +0400875 flush_itimer_signals();
Oleg Nesterov329f7db2005-11-07 21:12:43 +0300876
Oleg Nesterovb2c903b2007-10-16 23:27:22 -0700877 if (atomic_read(&oldsighand->count) != 1) {
878 struct sighand_struct *newsighand;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 /*
Oleg Nesterovb2c903b2007-10-16 23:27:22 -0700880 * This ->sighand is shared with the CLONE_SIGHAND
881 * but not CLONE_THREAD task, switch to the new one.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 */
Oleg Nesterovb2c903b2007-10-16 23:27:22 -0700883 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
884 if (!newsighand)
885 return -ENOMEM;
886
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 atomic_set(&newsighand->count, 1);
888 memcpy(newsighand->action, oldsighand->action,
889 sizeof(newsighand->action));
890
891 write_lock_irq(&tasklist_lock);
892 spin_lock(&oldsighand->siglock);
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700893 rcu_assign_pointer(tsk->sighand, newsighand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 spin_unlock(&oldsighand->siglock);
895 write_unlock_irq(&tasklist_lock);
896
Davide Libenzifba2afa2007-05-10 22:23:13 -0700897 __cleanup_sighand(oldsighand);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 }
899
Eric W. Biedermanaafe6c22006-09-27 01:51:13 -0700900 BUG_ON(!thread_group_leader(tsk));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 return 0;
902}
Oleg Nesterov0840a902007-10-16 23:27:22 -0700903
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904/*
905 * These functions flushes out all traces of the currently running executable
906 * so that a new one can be started
907 */
Arjan van de Ven858119e2006-01-14 13:20:43 -0800908static void flush_old_files(struct files_struct * files)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909{
910 long j = -1;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700911 struct fdtable *fdt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912
913 spin_lock(&files->file_lock);
914 for (;;) {
915 unsigned long set, i;
916
917 j++;
918 i = j * __NFDBITS;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700919 fdt = files_fdtable(files);
Vadim Lobanovbbea9f62006-12-10 02:21:12 -0800920 if (i >= fdt->max_fds)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 break;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700922 set = fdt->close_on_exec->fds_bits[j];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 if (!set)
924 continue;
Dipankar Sarmabadf1662005-09-09 13:04:10 -0700925 fdt->close_on_exec->fds_bits[j] = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 spin_unlock(&files->file_lock);
927 for ( ; set ; i++,set >>= 1) {
928 if (set & 1) {
929 sys_close(i);
930 }
931 }
932 spin_lock(&files->file_lock);
933
934 }
935 spin_unlock(&files->file_lock);
936}
937
Andrew Morton59714d62008-02-04 22:27:21 -0800938char *get_task_comm(char *buf, struct task_struct *tsk)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939{
940 /* buf must be at least sizeof(tsk->comm) in size */
941 task_lock(tsk);
942 strncpy(buf, tsk->comm, sizeof(tsk->comm));
943 task_unlock(tsk);
Andrew Morton59714d62008-02-04 22:27:21 -0800944 return buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945}
946
947void set_task_comm(struct task_struct *tsk, char *buf)
948{
949 task_lock(tsk);
950 strlcpy(tsk->comm, buf, sizeof(tsk->comm));
951 task_unlock(tsk);
952}
953
954int flush_old_exec(struct linux_binprm * bprm)
955{
956 char * name;
957 int i, ch, retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 char tcomm[sizeof(current->comm)];
959
960 /*
961 * Make sure we have a private signal table and that
962 * we are unassociated from the previous thread group.
963 */
964 retval = de_thread(current);
965 if (retval)
966 goto out;
967
Matt Helsley925d1c42008-04-29 01:01:36 -0700968 set_mm_exe_file(bprm->mm, bprm->file);
969
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 * Release all of the old mmap stuff
972 */
973 retval = exec_mmap(bprm->mm);
974 if (retval)
Al Virofd8328b2008-04-22 05:11:59 -0400975 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976
977 bprm->mm = NULL; /* We're using it now */
978
979 /* This is the point of no return */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 current->sas_ss_sp = current->sas_ss_size = 0;
981
David Howellsda9592e2008-11-14 10:39:05 +1100982 if (current_euid() == current_uid() && current_egid() == current_gid())
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700983 set_dumpable(current->mm, 1);
Alan Coxd6e71142005-06-23 00:09:43 -0700984 else
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -0700985 set_dumpable(current->mm, suid_dumpable);
Alan Coxd6e71142005-06-23 00:09:43 -0700986
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 name = bprm->filename;
Paolo 'Blaisorblade' Giarrusso36772092005-05-05 16:16:12 -0700988
989 /* Copies the binary name from after last slash */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 for (i=0; (ch = *(name++)) != '\0';) {
991 if (ch == '/')
Paolo 'Blaisorblade' Giarrusso36772092005-05-05 16:16:12 -0700992 i = 0; /* overwrite what we wrote */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 else
994 if (i < (sizeof(tcomm) - 1))
995 tcomm[i++] = ch;
996 }
997 tcomm[i] = '\0';
998 set_task_comm(current, tcomm);
999
1000 current->flags &= ~PF_RANDOMIZE;
1001 flush_thread();
1002
Benjamin Herrenschmidt0551fbd2006-02-28 16:59:19 -08001003 /* Set the new mm task size. We have to do that late because it may
1004 * depend on TIF_32BIT which is only updated in flush_thread() on
1005 * some architectures like powerpc
1006 */
1007 current->mm->task_size = TASK_SIZE;
1008
David Howellsa6f76f22008-11-14 10:39:24 +11001009 /* install the new credentials */
1010 if (bprm->cred->uid != current_euid() ||
1011 bprm->cred->gid != current_egid()) {
Marcel Holtmannd2d56c52007-08-17 21:47:58 +02001012 current->pdeath_signal = 0;
1013 } else if (file_permission(bprm->file, MAY_READ) ||
David Howellsa6f76f22008-11-14 10:39:24 +11001014 bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) {
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -07001015 set_dumpable(current->mm, suid_dumpable);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 }
1017
David Howellsa6f76f22008-11-14 10:39:24 +11001018 current->personality &= ~bprm->per_clear;
1019
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020 /* An exec changes our domain. We are no longer part of the thread
1021 group */
1022
1023 current->self_exec_id++;
1024
1025 flush_signal_handlers(current, 0);
1026 flush_old_files(current->files);
1027
1028 return 0;
1029
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030out:
1031 return retval;
1032}
1033
1034EXPORT_SYMBOL(flush_old_exec);
1035
David Howellsa6f76f22008-11-14 10:39:24 +11001036/*
1037 * install the new credentials for this executable
1038 */
1039void install_exec_creds(struct linux_binprm *bprm)
1040{
1041 security_bprm_committing_creds(bprm);
1042
1043 commit_creds(bprm->cred);
1044 bprm->cred = NULL;
1045
1046 /* cred_exec_mutex must be held at least to this point to prevent
1047 * ptrace_attach() from altering our determination of the task's
1048 * credentials; any time after this it may be unlocked */
1049
1050 security_bprm_committed_creds(bprm);
1051}
1052EXPORT_SYMBOL(install_exec_creds);
1053
1054/*
1055 * determine how safe it is to execute the proposed program
1056 * - the caller must hold current->cred_exec_mutex to protect against
1057 * PTRACE_ATTACH
1058 */
Al Viro498052b2009-03-30 07:20:30 -04001059int check_unsafe_exec(struct linux_binprm *bprm)
David Howellsa6f76f22008-11-14 10:39:24 +11001060{
David Howells0bf2f3a2009-02-06 11:45:46 +00001061 struct task_struct *p = current, *t;
1062 unsigned long flags;
Al Virof1191b52009-03-30 07:35:18 -04001063 unsigned n_fs;
Al Viro498052b2009-03-30 07:20:30 -04001064 int res = 0;
David Howellsa6f76f22008-11-14 10:39:24 +11001065
1066 bprm->unsafe = tracehook_unsafe_exec(p);
1067
David Howells0bf2f3a2009-02-06 11:45:46 +00001068 n_fs = 1;
Al Viro498052b2009-03-30 07:20:30 -04001069 write_lock(&p->fs->lock);
David Howells0bf2f3a2009-02-06 11:45:46 +00001070 lock_task_sighand(p, &flags);
1071 for (t = next_thread(p); t != p; t = next_thread(t)) {
1072 if (t->fs == p->fs)
1073 n_fs++;
David Howells0bf2f3a2009-02-06 11:45:46 +00001074 }
1075
Al Virof1191b52009-03-30 07:35:18 -04001076 if (p->fs->users > n_fs) {
David Howellsa6f76f22008-11-14 10:39:24 +11001077 bprm->unsafe |= LSM_UNSAFE_SHARE;
Al Viro498052b2009-03-30 07:20:30 -04001078 } else {
1079 if (p->fs->in_exec)
1080 res = -EAGAIN;
1081 p->fs->in_exec = 1;
1082 }
David Howells0bf2f3a2009-02-06 11:45:46 +00001083
1084 unlock_task_sighand(p, &flags);
Al Viro498052b2009-03-30 07:20:30 -04001085 write_unlock(&p->fs->lock);
1086
1087 return res;
David Howellsa6f76f22008-11-14 10:39:24 +11001088}
1089
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090/*
1091 * Fill the binprm structure from the inode.
1092 * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
David Howellsa6f76f22008-11-14 10:39:24 +11001093 *
1094 * This may be called multiple times for binary chains (scripts for example).
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 */
1096int prepare_binprm(struct linux_binprm *bprm)
1097{
David Howellsa6f76f22008-11-14 10:39:24 +11001098 umode_t mode;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001099 struct inode * inode = bprm->file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 int retval;
1101
1102 mode = inode->i_mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 if (bprm->file->f_op == NULL)
1104 return -EACCES;
1105
David Howellsa6f76f22008-11-14 10:39:24 +11001106 /* clear any previous set[ug]id data from a previous binary */
1107 bprm->cred->euid = current_euid();
1108 bprm->cred->egid = current_egid();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109
David Howellsa6f76f22008-11-14 10:39:24 +11001110 if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 /* Set-uid? */
1112 if (mode & S_ISUID) {
David Howellsa6f76f22008-11-14 10:39:24 +11001113 bprm->per_clear |= PER_CLEAR_ON_SETID;
1114 bprm->cred->euid = inode->i_uid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 }
1116
1117 /* Set-gid? */
1118 /*
1119 * If setgid is set but no group execute bit then this
1120 * is a candidate for mandatory locking, not a setgid
1121 * executable.
1122 */
1123 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
David Howellsa6f76f22008-11-14 10:39:24 +11001124 bprm->per_clear |= PER_CLEAR_ON_SETID;
1125 bprm->cred->egid = inode->i_gid;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 }
1127 }
1128
1129 /* fill in binprm security blob */
David Howellsa6f76f22008-11-14 10:39:24 +11001130 retval = security_bprm_set_creds(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 if (retval)
1132 return retval;
David Howellsa6f76f22008-11-14 10:39:24 +11001133 bprm->cred_prepared = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134
David Howellsa6f76f22008-11-14 10:39:24 +11001135 memset(bprm->buf, 0, BINPRM_BUF_SIZE);
1136 return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137}
1138
1139EXPORT_SYMBOL(prepare_binprm);
1140
Nick Piggin4fc75ff2007-05-08 00:25:16 -07001141/*
1142 * Arguments are '\0' separated strings found at the location bprm->p
1143 * points to; chop off the first by relocating brpm->p to right after
1144 * the first '\0' encountered.
1145 */
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001146int remove_arg_zero(struct linux_binprm *bprm)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147{
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001148 int ret = 0;
1149 unsigned long offset;
1150 char *kaddr;
1151 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001153 if (!bprm->argc)
1154 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001156 do {
1157 offset = bprm->p & ~PAGE_MASK;
1158 page = get_arg_page(bprm, bprm->p, 0);
1159 if (!page) {
1160 ret = -EFAULT;
1161 goto out;
1162 }
1163 kaddr = kmap_atomic(page, KM_USER0);
Nick Piggin4fc75ff2007-05-08 00:25:16 -07001164
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001165 for (; offset < PAGE_SIZE && kaddr[offset];
1166 offset++, bprm->p++)
1167 ;
Nick Piggin4fc75ff2007-05-08 00:25:16 -07001168
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001169 kunmap_atomic(kaddr, KM_USER0);
1170 put_arg_page(page);
Nick Piggin4fc75ff2007-05-08 00:25:16 -07001171
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001172 if (offset == PAGE_SIZE)
1173 free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1);
1174 } while (offset == PAGE_SIZE);
Nick Piggin4fc75ff2007-05-08 00:25:16 -07001175
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001176 bprm->p++;
1177 bprm->argc--;
1178 ret = 0;
Nick Piggin4fc75ff2007-05-08 00:25:16 -07001179
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001180out:
1181 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183EXPORT_SYMBOL(remove_arg_zero);
1184
1185/*
1186 * cycle the list of binary formats handler, until one recognizes the image
1187 */
1188int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
1189{
Roland McGrath85f33462008-12-09 19:36:38 -08001190 unsigned int depth = bprm->recursion_depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 int try,retval;
1192 struct linux_binfmt *fmt;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001193
Linus Torvalds1da177e2005-04-16 15:20:36 -07001194 retval = security_bprm_check(bprm);
1195 if (retval)
1196 return retval;
Mimi Zohar6146f0d2009-02-04 09:06:57 -05001197 retval = ima_bprm_check(bprm);
1198 if (retval)
1199 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200
1201 /* kernel module loader fixup */
1202 /* so we don't try to load run modprobe in kernel space. */
1203 set_fs(USER_DS);
Al Viro473ae302006-04-26 14:04:08 -04001204
1205 retval = audit_bprm(bprm);
1206 if (retval)
1207 return retval;
1208
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 retval = -ENOENT;
1210 for (try=0; try<2; try++) {
1211 read_lock(&binfmt_lock);
Alexey Dobriyane4dc1b12007-10-16 23:26:03 -07001212 list_for_each_entry(fmt, &formats, lh) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
1214 if (!fn)
1215 continue;
1216 if (!try_module_get(fmt->module))
1217 continue;
1218 read_unlock(&binfmt_lock);
1219 retval = fn(bprm, regs);
Roland McGrath85f33462008-12-09 19:36:38 -08001220 /*
1221 * Restore the depth counter to its starting value
1222 * in this call, so we don't have to rely on every
1223 * load_binary function to restore it on return.
1224 */
1225 bprm->recursion_depth = depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 if (retval >= 0) {
Roland McGrath85f33462008-12-09 19:36:38 -08001227 if (depth == 0)
1228 tracehook_report_exec(fmt, bprm, regs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 put_binfmt(fmt);
1230 allow_write_access(bprm->file);
1231 if (bprm->file)
1232 fput(bprm->file);
1233 bprm->file = NULL;
1234 current->did_exec = 1;
Matt Helsley9f460802005-11-07 00:59:16 -08001235 proc_exec_connector(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 return retval;
1237 }
1238 read_lock(&binfmt_lock);
1239 put_binfmt(fmt);
1240 if (retval != -ENOEXEC || bprm->mm == NULL)
1241 break;
1242 if (!bprm->file) {
1243 read_unlock(&binfmt_lock);
1244 return retval;
1245 }
1246 }
1247 read_unlock(&binfmt_lock);
1248 if (retval != -ENOEXEC || bprm->mm == NULL) {
1249 break;
Johannes Berg5f4123b2008-07-09 10:28:40 +02001250#ifdef CONFIG_MODULES
1251 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
1253 if (printable(bprm->buf[0]) &&
1254 printable(bprm->buf[1]) &&
1255 printable(bprm->buf[2]) &&
1256 printable(bprm->buf[3]))
1257 break; /* -ENOEXEC */
1258 request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
1259#endif
1260 }
1261 }
1262 return retval;
1263}
1264
1265EXPORT_SYMBOL(search_binary_handler);
1266
Al Viro08a6fac2008-05-10 16:38:25 -04001267void free_bprm(struct linux_binprm *bprm)
1268{
1269 free_arg_pages(bprm);
David Howellsa6f76f22008-11-14 10:39:24 +11001270 if (bprm->cred)
1271 abort_creds(bprm->cred);
Al Viro08a6fac2008-05-10 16:38:25 -04001272 kfree(bprm);
1273}
1274
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275/*
1276 * sys_execve() executes a new program.
1277 */
1278int do_execve(char * filename,
1279 char __user *__user *argv,
1280 char __user *__user *envp,
1281 struct pt_regs * regs)
1282{
1283 struct linux_binprm *bprm;
1284 struct file *file;
Al Viro3b125382008-04-22 05:31:30 -04001285 struct files_struct *displaced;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 int retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287
Al Viro3b125382008-04-22 05:31:30 -04001288 retval = unshare_files(&displaced);
Al Virofd8328b2008-04-22 05:11:59 -04001289 if (retval)
1290 goto out_ret;
1291
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292 retval = -ENOMEM;
Oliver Neukum11b0b5a2006-03-25 03:08:13 -08001293 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 if (!bprm)
Al Virofd8328b2008-04-22 05:11:59 -04001295 goto out_files;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296
David Howellsa6f76f22008-11-14 10:39:24 +11001297 retval = mutex_lock_interruptible(&current->cred_exec_mutex);
1298 if (retval < 0)
1299 goto out_free;
Kentaro Takedaf9ce1f12009-02-05 17:18:11 +09001300 current->in_execve = 1;
David Howellsa6f76f22008-11-14 10:39:24 +11001301
1302 retval = -ENOMEM;
1303 bprm->cred = prepare_exec_creds();
1304 if (!bprm->cred)
1305 goto out_unlock;
Al Viro498052b2009-03-30 07:20:30 -04001306
1307 retval = check_unsafe_exec(bprm);
1308 if (retval)
1309 goto out_unlock;
David Howellsa6f76f22008-11-14 10:39:24 +11001310
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 file = open_exec(filename);
1312 retval = PTR_ERR(file);
1313 if (IS_ERR(file))
Al Viro498052b2009-03-30 07:20:30 -04001314 goto out_unmark;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315
1316 sched_exec();
1317
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 bprm->file = file;
1319 bprm->filename = filename;
1320 bprm->interp = filename;
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001321
1322 retval = bprm_mm_init(bprm);
1323 if (retval)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 goto out_file;
1325
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001326 bprm->argc = count(argv, MAX_ARG_STRINGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 if ((retval = bprm->argc) < 0)
David Howellsa6f76f22008-11-14 10:39:24 +11001328 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001330 bprm->envc = count(envp, MAX_ARG_STRINGS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 if ((retval = bprm->envc) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332 goto out;
1333
1334 retval = prepare_binprm(bprm);
1335 if (retval < 0)
1336 goto out;
1337
1338 retval = copy_strings_kernel(1, &bprm->filename, bprm);
1339 if (retval < 0)
1340 goto out;
1341
1342 bprm->exec = bprm->p;
1343 retval = copy_strings(bprm->envc, envp, bprm);
1344 if (retval < 0)
1345 goto out;
1346
1347 retval = copy_strings(bprm->argc, argv, bprm);
1348 if (retval < 0)
1349 goto out;
1350
Oleg Nesterov7b34e422008-07-25 01:47:37 -07001351 current->flags &= ~PF_KTHREAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 retval = search_binary_handler(bprm,regs);
David Howellsa6f76f22008-11-14 10:39:24 +11001353 if (retval < 0)
1354 goto out;
1355
1356 /* execve succeeded */
Al Viro498052b2009-03-30 07:20:30 -04001357 write_lock(&current->fs->lock);
1358 current->fs->in_exec = 0;
1359 write_unlock(&current->fs->lock);
Kentaro Takedaf9ce1f12009-02-05 17:18:11 +09001360 current->in_execve = 0;
David Howellsa6f76f22008-11-14 10:39:24 +11001361 mutex_unlock(&current->cred_exec_mutex);
1362 acct_update_integrals(current);
1363 free_bprm(bprm);
1364 if (displaced)
1365 put_files_struct(displaced);
1366 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001367
1368out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 if (bprm->mm)
Ollie Wildb6a2fea2007-07-19 01:48:16 -07001370 mmput (bprm->mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371
1372out_file:
1373 if (bprm->file) {
1374 allow_write_access(bprm->file);
1375 fput(bprm->file);
1376 }
David Howellsa6f76f22008-11-14 10:39:24 +11001377
Al Viro498052b2009-03-30 07:20:30 -04001378out_unmark:
1379 write_lock(&current->fs->lock);
1380 current->fs->in_exec = 0;
1381 write_unlock(&current->fs->lock);
1382
David Howellsa6f76f22008-11-14 10:39:24 +11001383out_unlock:
Kentaro Takedaf9ce1f12009-02-05 17:18:11 +09001384 current->in_execve = 0;
David Howellsa6f76f22008-11-14 10:39:24 +11001385 mutex_unlock(&current->cred_exec_mutex);
1386
1387out_free:
Al Viro08a6fac2008-05-10 16:38:25 -04001388 free_bprm(bprm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389
Al Virofd8328b2008-04-22 05:11:59 -04001390out_files:
Al Viro3b125382008-04-22 05:31:30 -04001391 if (displaced)
1392 reset_files_struct(displaced);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393out_ret:
1394 return retval;
1395}
1396
1397int set_binfmt(struct linux_binfmt *new)
1398{
1399 struct linux_binfmt *old = current->binfmt;
1400
1401 if (new) {
1402 if (!try_module_get(new->module))
1403 return -1;
1404 }
1405 current->binfmt = new;
1406 if (old)
1407 module_put(old->module);
1408 return 0;
1409}
1410
1411EXPORT_SYMBOL(set_binfmt);
1412
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413/* format_corename will inspect the pattern parameter, and output a
1414 * name into corename, which must have space for at least
1415 * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
1416 */
Oleg Nesterov64093242008-10-18 20:28:22 -07001417static int format_corename(char *corename, long signr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418{
David Howells86a264a2008-11-14 10:39:18 +11001419 const struct cred *cred = current_cred();
Oleg Nesterov565b9b12008-07-25 01:47:47 -07001420 const char *pat_ptr = core_pattern;
1421 int ispipe = (*pat_ptr == '|');
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422 char *out_ptr = corename;
1423 char *const out_end = corename + CORENAME_MAX_SIZE;
1424 int rc;
1425 int pid_in_pattern = 0;
1426
1427 /* Repeat as long as we have more pattern to process and more output
1428 space */
1429 while (*pat_ptr) {
1430 if (*pat_ptr != '%') {
1431 if (out_ptr == out_end)
1432 goto out;
1433 *out_ptr++ = *pat_ptr++;
1434 } else {
1435 switch (*++pat_ptr) {
1436 case 0:
1437 goto out;
1438 /* Double percent, output one percent */
1439 case '%':
1440 if (out_ptr == out_end)
1441 goto out;
1442 *out_ptr++ = '%';
1443 break;
1444 /* pid */
1445 case 'p':
1446 pid_in_pattern = 1;
1447 rc = snprintf(out_ptr, out_end - out_ptr,
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001448 "%d", task_tgid_vnr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 if (rc > out_end - out_ptr)
1450 goto out;
1451 out_ptr += rc;
1452 break;
1453 /* uid */
1454 case 'u':
1455 rc = snprintf(out_ptr, out_end - out_ptr,
David Howells86a264a2008-11-14 10:39:18 +11001456 "%d", cred->uid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 if (rc > out_end - out_ptr)
1458 goto out;
1459 out_ptr += rc;
1460 break;
1461 /* gid */
1462 case 'g':
1463 rc = snprintf(out_ptr, out_end - out_ptr,
David Howells86a264a2008-11-14 10:39:18 +11001464 "%d", cred->gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465 if (rc > out_end - out_ptr)
1466 goto out;
1467 out_ptr += rc;
1468 break;
1469 /* signal that caused the coredump */
1470 case 's':
1471 rc = snprintf(out_ptr, out_end - out_ptr,
1472 "%ld", signr);
1473 if (rc > out_end - out_ptr)
1474 goto out;
1475 out_ptr += rc;
1476 break;
1477 /* UNIX time of coredump */
1478 case 't': {
1479 struct timeval tv;
1480 do_gettimeofday(&tv);
1481 rc = snprintf(out_ptr, out_end - out_ptr,
1482 "%lu", tv.tv_sec);
1483 if (rc > out_end - out_ptr)
1484 goto out;
1485 out_ptr += rc;
1486 break;
1487 }
1488 /* hostname */
1489 case 'h':
1490 down_read(&uts_sem);
1491 rc = snprintf(out_ptr, out_end - out_ptr,
Serge E. Hallyne9ff3992006-10-02 02:18:11 -07001492 "%s", utsname()->nodename);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001493 up_read(&uts_sem);
1494 if (rc > out_end - out_ptr)
1495 goto out;
1496 out_ptr += rc;
1497 break;
1498 /* executable */
1499 case 'e':
1500 rc = snprintf(out_ptr, out_end - out_ptr,
1501 "%s", current->comm);
1502 if (rc > out_end - out_ptr)
1503 goto out;
1504 out_ptr += rc;
1505 break;
Neil Horman74aadce2007-10-16 23:26:35 -07001506 /* core limit size */
1507 case 'c':
1508 rc = snprintf(out_ptr, out_end - out_ptr,
1509 "%lu", current->signal->rlim[RLIMIT_CORE].rlim_cur);
1510 if (rc > out_end - out_ptr)
1511 goto out;
1512 out_ptr += rc;
1513 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001514 default:
1515 break;
1516 }
1517 ++pat_ptr;
1518 }
1519 }
1520 /* Backward compatibility with core_uses_pid:
1521 *
1522 * If core_pattern does not include a %p (as is the default)
1523 * and core_uses_pid is set, then .%pid will be appended to
Alan Coxc4bbafd2007-04-16 22:53:13 -07001524 * the filename. Do not do this for piped commands. */
Oleg Nesterov64093242008-10-18 20:28:22 -07001525 if (!ispipe && !pid_in_pattern && core_uses_pid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526 rc = snprintf(out_ptr, out_end - out_ptr,
Pavel Emelyanovb4888932007-10-18 23:40:14 -07001527 ".%d", task_tgid_vnr(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 if (rc > out_end - out_ptr)
1529 goto out;
1530 out_ptr += rc;
1531 }
Alan Coxc4bbafd2007-04-16 22:53:13 -07001532out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001533 *out_ptr = 0;
Alan Coxc4bbafd2007-04-16 22:53:13 -07001534 return ispipe;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535}
1536
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001537static int zap_process(struct task_struct *start)
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001538{
1539 struct task_struct *t;
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001540 int nr = 0;
Oleg Nesterov281de332006-06-26 00:26:06 -07001541
Oleg Nesterovd5f70c02006-06-26 00:26:07 -07001542 start->signal->flags = SIGNAL_GROUP_EXIT;
1543 start->signal->group_stop_count = 0;
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001544
1545 t = start;
1546 do {
1547 if (t != current && t->mm) {
Oleg Nesterov281de332006-06-26 00:26:06 -07001548 sigaddset(&t->pending.signal, SIGKILL);
1549 signal_wake_up(t, 1);
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001550 nr++;
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001551 }
Oleg Nesterove4901f92008-07-25 01:47:31 -07001552 } while_each_thread(start, t);
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001553
1554 return nr;
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001555}
1556
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001557static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm,
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001558 struct core_state *core_state, int exit_code)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559{
1560 struct task_struct *g, *p;
Oleg Nesterov5debfa62006-06-26 00:26:09 -07001561 unsigned long flags;
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001562 int nr = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001564 spin_lock_irq(&tsk->sighand->siglock);
Oleg Nesteroved5d2ca2008-02-04 22:27:24 -08001565 if (!signal_group_exit(tsk->signal)) {
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001566 mm->core_state = core_state;
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001567 tsk->signal->group_exit_code = exit_code;
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001568 nr = zap_process(tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001569 }
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001570 spin_unlock_irq(&tsk->sighand->siglock);
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001571 if (unlikely(nr < 0))
1572 return nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001573
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001574 if (atomic_read(&mm->mm_users) == nr + 1)
Oleg Nesterov5debfa62006-06-26 00:26:09 -07001575 goto done;
Oleg Nesterove4901f92008-07-25 01:47:31 -07001576 /*
1577 * We should find and kill all tasks which use this mm, and we should
Oleg Nesterov999d9fc2008-07-25 01:47:41 -07001578 * count them correctly into ->nr_threads. We don't take tasklist
Oleg Nesterove4901f92008-07-25 01:47:31 -07001579 * lock, but this is safe wrt:
1580 *
1581 * fork:
1582 * None of sub-threads can fork after zap_process(leader). All
1583 * processes which were created before this point should be
1584 * visible to zap_threads() because copy_process() adds the new
1585 * process to the tail of init_task.tasks list, and lock/unlock
1586 * of ->siglock provides a memory barrier.
1587 *
1588 * do_exit:
1589 * The caller holds mm->mmap_sem. This means that the task which
1590 * uses this mm can't pass exit_mm(), so it can't exit or clear
1591 * its ->mm.
1592 *
1593 * de_thread:
1594 * It does list_replace_rcu(&leader->tasks, &current->tasks),
1595 * we must see either old or new leader, this does not matter.
1596 * However, it can change p->sighand, so lock_task_sighand(p)
1597 * must be used. Since p->mm != NULL and we hold ->mmap_sem
1598 * it can't fail.
1599 *
1600 * Note also that "g" can be the old leader with ->mm == NULL
1601 * and already unhashed and thus removed from ->thread_group.
1602 * This is OK, __unhash_process()->list_del_rcu() does not
1603 * clear the ->next pointer, we will find the new leader via
1604 * next_thread().
1605 */
Oleg Nesterov7b1c6152006-06-26 00:26:08 -07001606 rcu_read_lock();
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001607 for_each_process(g) {
Oleg Nesterov5debfa62006-06-26 00:26:09 -07001608 if (g == tsk->group_leader)
1609 continue;
Oleg Nesterov15b9f362008-07-25 01:47:39 -07001610 if (g->flags & PF_KTHREAD)
1611 continue;
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001612 p = g;
1613 do {
1614 if (p->mm) {
Oleg Nesterov15b9f362008-07-25 01:47:39 -07001615 if (unlikely(p->mm == mm)) {
Oleg Nesterov5debfa62006-06-26 00:26:09 -07001616 lock_task_sighand(p, &flags);
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001617 nr += zap_process(p);
Oleg Nesterov5debfa62006-06-26 00:26:09 -07001618 unlock_task_sighand(p, &flags);
1619 }
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001620 break;
1621 }
Oleg Nesterove4901f92008-07-25 01:47:31 -07001622 } while_each_thread(g, p);
Oleg Nesterovaceecc02006-06-26 00:26:05 -07001623 }
Oleg Nesterov7b1c6152006-06-26 00:26:08 -07001624 rcu_read_unlock();
Oleg Nesterov5debfa62006-06-26 00:26:09 -07001625done:
Oleg Nesterovc5f1cc82008-07-25 01:47:42 -07001626 atomic_set(&core_state->nr_threads, nr);
Oleg Nesterov8cd9c242008-07-25 01:47:42 -07001627 return nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628}
1629
Oleg Nesterov9d5b3272008-07-25 01:47:43 -07001630static int coredump_wait(int exit_code, struct core_state *core_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631{
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001632 struct task_struct *tsk = current;
1633 struct mm_struct *mm = tsk->mm;
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001634 struct completion *vfork_done;
Oleg Nesterov2384f552005-10-30 15:02:47 -08001635 int core_waiters;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001636
Oleg Nesterov9d5b3272008-07-25 01:47:43 -07001637 init_completion(&core_state->startup);
Oleg Nesterovb564daf2008-07-25 01:47:44 -07001638 core_state->dumper.task = tsk;
1639 core_state->dumper.next = NULL;
Oleg Nesterov9d5b3272008-07-25 01:47:43 -07001640 core_waiters = zap_threads(tsk, mm, core_state, exit_code);
Oleg Nesterov2384f552005-10-30 15:02:47 -08001641 up_write(&mm->mmap_sem);
1642
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001643 if (unlikely(core_waiters < 0))
1644 goto fail;
1645
1646 /*
1647 * Make sure nobody is waiting for us to release the VM,
1648 * otherwise we can deadlock when we wait on each other
1649 */
1650 vfork_done = tsk->vfork_done;
1651 if (vfork_done) {
1652 tsk->vfork_done = NULL;
1653 complete(vfork_done);
1654 }
1655
Oleg Nesterov2384f552005-10-30 15:02:47 -08001656 if (core_waiters)
Oleg Nesterov9d5b3272008-07-25 01:47:43 -07001657 wait_for_completion(&core_state->startup);
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001658fail:
Oleg Nesterovdcf560c2006-06-26 00:26:08 -07001659 return core_waiters;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001660}
1661
Oleg Nesterova94e2d42008-07-25 01:47:46 -07001662static void coredump_finish(struct mm_struct *mm)
1663{
1664 struct core_thread *curr, *next;
1665 struct task_struct *task;
1666
1667 next = mm->core_state->dumper.next;
1668 while ((curr = next) != NULL) {
1669 next = curr->next;
1670 task = curr->task;
1671 /*
1672 * see exit_mm(), curr->task must not see
1673 * ->task == NULL before we read ->next.
1674 */
1675 smp_mb();
1676 curr->task = NULL;
1677 wake_up_process(task);
1678 }
1679
1680 mm->core_state = NULL;
1681}
1682
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -07001683/*
1684 * set_dumpable converts traditional three-value dumpable to two flags and
1685 * stores them into mm->flags. It modifies lower two bits of mm->flags, but
1686 * these bits are not changed atomically. So get_dumpable can observe the
1687 * intermediate state. To avoid doing unexpected behavior, get get_dumpable
1688 * return either old dumpable or new one by paying attention to the order of
1689 * modifying the bits.
1690 *
1691 * dumpable | mm->flags (binary)
1692 * old new | initial interim final
1693 * ---------+-----------------------
1694 * 0 1 | 00 01 01
1695 * 0 2 | 00 10(*) 11
1696 * 1 0 | 01 00 00
1697 * 1 2 | 01 11 11
1698 * 2 0 | 11 10(*) 00
1699 * 2 1 | 11 11 01
1700 *
1701 * (*) get_dumpable regards interim value of 10 as 11.
1702 */
1703void set_dumpable(struct mm_struct *mm, int value)
1704{
1705 switch (value) {
1706 case 0:
1707 clear_bit(MMF_DUMPABLE, &mm->flags);
1708 smp_wmb();
1709 clear_bit(MMF_DUMP_SECURELY, &mm->flags);
1710 break;
1711 case 1:
1712 set_bit(MMF_DUMPABLE, &mm->flags);
1713 smp_wmb();
1714 clear_bit(MMF_DUMP_SECURELY, &mm->flags);
1715 break;
1716 case 2:
1717 set_bit(MMF_DUMP_SECURELY, &mm->flags);
1718 smp_wmb();
1719 set_bit(MMF_DUMPABLE, &mm->flags);
1720 break;
1721 }
1722}
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -07001723
1724int get_dumpable(struct mm_struct *mm)
1725{
1726 int ret;
1727
1728 ret = mm->flags & 0x3;
1729 return (ret >= 2) ? 2 : ret;
1730}
1731
WANG Cong8cd3ac32009-01-06 14:42:48 -08001732void do_coredump(long signr, int exit_code, struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733{
Oleg Nesterov9d5b3272008-07-25 01:47:43 -07001734 struct core_state core_state;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 char corename[CORENAME_MAX_SIZE + 1];
1736 struct mm_struct *mm = current->mm;
1737 struct linux_binfmt * binfmt;
1738 struct inode * inode;
1739 struct file * file;
David Howellsd84f4f92008-11-14 10:39:23 +11001740 const struct cred *old_cred;
1741 struct cred *cred;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 int retval = 0;
Alan Coxd6e71142005-06-23 00:09:43 -07001743 int flag = 0;
Andi Kleend025c9d2006-09-30 23:29:28 -07001744 int ispipe = 0;
Neil Horman7dc0b222007-10-16 23:26:34 -07001745 unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
Neil Horman74aadce2007-10-16 23:26:35 -07001746 char **helper_argv = NULL;
1747 int helper_argc = 0;
1748 char *delimit;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001749
Steve Grubb0a4ff8c2007-04-19 10:28:21 -04001750 audit_core_dumps(signr);
1751
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752 binfmt = current->binfmt;
1753 if (!binfmt || !binfmt->core_dump)
1754 goto fail;
David Howellsd84f4f92008-11-14 10:39:23 +11001755
1756 cred = prepare_creds();
1757 if (!cred) {
1758 retval = -ENOMEM;
1759 goto fail;
1760 }
1761
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762 down_write(&mm->mmap_sem);
Roland McGrath00ec99d2007-11-11 19:13:43 -08001763 /*
1764 * If another thread got here first, or we are not dumpable, bail out.
1765 */
Oleg Nesterov999d9fc2008-07-25 01:47:41 -07001766 if (mm->core_state || !get_dumpable(mm)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001767 up_write(&mm->mmap_sem);
David Howellsd84f4f92008-11-14 10:39:23 +11001768 put_cred(cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001769 goto fail;
1770 }
Alan Coxd6e71142005-06-23 00:09:43 -07001771
1772 /*
1773 * We cannot trust fsuid as being the "true" uid of the
1774 * process nor do we know its entire history. We only know it
1775 * was tainted so we dump it as root in mode 2.
1776 */
Kawai, Hidehiro6c5d5232007-07-19 01:48:27 -07001777 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */
Alan Coxd6e71142005-06-23 00:09:43 -07001778 flag = O_EXCL; /* Stop rewrite attacks */
David Howellsd84f4f92008-11-14 10:39:23 +11001779 cred->fsuid = 0; /* Dump root private */
Alan Coxd6e71142005-06-23 00:09:43 -07001780 }
Oleg Nesterov1291cf42005-10-30 15:02:54 -08001781
Oleg Nesterov9d5b3272008-07-25 01:47:43 -07001782 retval = coredump_wait(exit_code, &core_state);
David Howellsd84f4f92008-11-14 10:39:23 +11001783 if (retval < 0) {
1784 put_cred(cred);
Oleg Nesterov1291cf42005-10-30 15:02:54 -08001785 goto fail;
David Howellsd84f4f92008-11-14 10:39:23 +11001786 }
1787
1788 old_cred = override_creds(cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789
1790 /*
1791 * Clear any false indication of pending signals that might
1792 * be seen by the filesystem code called to write the core file.
1793 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794 clear_thread_flag(TIF_SIGPENDING);
1795
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796 /*
1797 * lock_kernel() because format_corename() is controlled by sysctl, which
1798 * uses lock_kernel()
1799 */
1800 lock_kernel();
Oleg Nesterov64093242008-10-18 20:28:22 -07001801 ispipe = format_corename(corename, signr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 unlock_kernel();
Neil Horman7dc0b222007-10-16 23:26:34 -07001803 /*
1804 * Don't bother to check the RLIMIT_CORE value if core_pattern points
1805 * to a pipe. Since we're not writing directly to the filesystem
1806 * RLIMIT_CORE doesn't really apply, as no actual core file will be
1807 * created unless the pipe reader choses to write out the core file
1808 * at which point file size limits and permissions will be imposed
1809 * as it does with any other process
1810 */
Neil Horman74aadce2007-10-16 23:26:35 -07001811 if ((!ispipe) && (core_limit < binfmt->min_coredump))
Neil Horman7dc0b222007-10-16 23:26:34 -07001812 goto fail_unlock;
1813
Alan Coxc4bbafd2007-04-16 22:53:13 -07001814 if (ispipe) {
Neil Horman74aadce2007-10-16 23:26:35 -07001815 helper_argv = argv_split(GFP_KERNEL, corename+1, &helper_argc);
Tetsuo Handa350eaf72009-01-06 14:41:11 -08001816 if (!helper_argv) {
1817 printk(KERN_WARNING "%s failed to allocate memory\n",
1818 __func__);
1819 goto fail_unlock;
1820 }
Neil Horman74aadce2007-10-16 23:26:35 -07001821 /* Terminate the string before the first option */
1822 delimit = strchr(corename, ' ');
1823 if (delimit)
1824 *delimit = '\0';
Neil Horman32321132007-10-16 23:26:36 -07001825 delimit = strrchr(helper_argv[0], '/');
1826 if (delimit)
1827 delimit++;
1828 else
1829 delimit = helper_argv[0];
1830 if (!strcmp(delimit, current->comm)) {
1831 printk(KERN_NOTICE "Recursive core dump detected, "
1832 "aborting\n");
1833 goto fail_unlock;
1834 }
1835
1836 core_limit = RLIM_INFINITY;
1837
Andi Kleend025c9d2006-09-30 23:29:28 -07001838 /* SIGPIPE can happen, but it's just never processed */
Neil Horman32321132007-10-16 23:26:36 -07001839 if (call_usermodehelper_pipe(corename+1, helper_argv, NULL,
1840 &file)) {
Andi Kleend025c9d2006-09-30 23:29:28 -07001841 printk(KERN_INFO "Core dump to %s pipe failed\n",
1842 corename);
1843 goto fail_unlock;
1844 }
Andi Kleend025c9d2006-09-30 23:29:28 -07001845 } else
1846 file = filp_open(corename,
Alexey Dobriyan6d4df672006-12-06 20:40:39 -08001847 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
1848 0600);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849 if (IS_ERR(file))
1850 goto fail_unlock;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001851 inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852 if (inode->i_nlink > 1)
1853 goto close_fail; /* multiple links - don't dump */
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001854 if (!ispipe && d_unhashed(file->f_path.dentry))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 goto close_fail;
1856
Andi Kleend025c9d2006-09-30 23:29:28 -07001857 /* AK: actually i see no reason to not allow this for named pipes etc.,
1858 but keep the previous behaviour for now. */
1859 if (!ispipe && !S_ISREG(inode->i_mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001860 goto close_fail;
Ingo Molnarc46f7392007-11-28 13:59:18 +01001861 /*
1862 * Dont allow local users get cute and trick others to coredump
1863 * into their pre-created files:
1864 */
David Howellsda9592e2008-11-14 10:39:05 +11001865 if (inode->i_uid != current_fsuid())
Ingo Molnarc46f7392007-11-28 13:59:18 +01001866 goto close_fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001867 if (!file->f_op)
1868 goto close_fail;
1869 if (!file->f_op->write)
1870 goto close_fail;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -08001871 if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872 goto close_fail;
1873
Neil Horman7dc0b222007-10-16 23:26:34 -07001874 retval = binfmt->core_dump(signr, regs, file, core_limit);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001875
1876 if (retval)
1877 current->signal->group_exit_code |= 0x80;
1878close_fail:
1879 filp_close(file, NULL);
1880fail_unlock:
Neil Horman74aadce2007-10-16 23:26:35 -07001881 if (helper_argv)
1882 argv_free(helper_argv);
1883
David Howellsd84f4f92008-11-14 10:39:23 +11001884 revert_creds(old_cred);
1885 put_cred(cred);
Oleg Nesterova94e2d42008-07-25 01:47:46 -07001886 coredump_finish(mm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001887fail:
WANG Cong8cd3ac32009-01-06 14:42:48 -08001888 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001889}