iommu/msm: Reduce indentation
[linux-2.6-block.git] / fs / exec.c
CommitLineData
1da177e4
LT
1/*
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
613cc2b6 22 * formats.
1da177e4
LT
23 */
24
1da177e4
LT
25#include <linux/slab.h>
26#include <linux/file.h>
9f3acc31 27#include <linux/fdtable.h>
ba92a43d 28#include <linux/mm.h>
615d6e87 29#include <linux/vmacache.h>
1da177e4
LT
30#include <linux/stat.h>
31#include <linux/fcntl.h>
ba92a43d 32#include <linux/swap.h>
74aadce9 33#include <linux/string.h>
1da177e4 34#include <linux/init.h>
6e84f315 35#include <linux/sched/mm.h>
f7ccbae4 36#include <linux/sched/coredump.h>
3f07c014 37#include <linux/sched/signal.h>
6a3827d7 38#include <linux/sched/numa_balancing.h>
29930025 39#include <linux/sched/task.h>
ca5b172b 40#include <linux/pagemap.h>
cdd6c482 41#include <linux/perf_event.h>
1da177e4
LT
42#include <linux/highmem.h>
43#include <linux/spinlock.h>
44#include <linux/key.h>
45#include <linux/personality.h>
46#include <linux/binfmts.h>
1da177e4 47#include <linux/utsname.h>
84d73786 48#include <linux/pid_namespace.h>
1da177e4
LT
49#include <linux/module.h>
50#include <linux/namei.h>
1da177e4
LT
51#include <linux/mount.h>
52#include <linux/security.h>
53#include <linux/syscalls.h>
8f0ab514 54#include <linux/tsacct_kern.h>
9f46080c 55#include <linux/cn_proc.h>
473ae30b 56#include <linux/audit.h>
6341c393 57#include <linux/tracehook.h>
5f4123be 58#include <linux/kmod.h>
6110e3ab 59#include <linux/fsnotify.h>
5ad4e53b 60#include <linux/fs_struct.h>
61be228a 61#include <linux/pipe_fs_i.h>
3d5992d2 62#include <linux/oom.h>
0e028465 63#include <linux/compat.h>
b44a7dfc 64#include <linux/vmalloc.h>
1da177e4 65
7c0f6ba6 66#include <linux/uaccess.h>
1da177e4 67#include <asm/mmu_context.h>
b6a2fea3 68#include <asm/tlb.h>
43d2b113
KH
69
70#include <trace/events/task.h>
a6f76f23 71#include "internal.h"
1da177e4 72
4ff16c25
DS
73#include <trace/events/sched.h>
74
d6e71144
AC
75int suid_dumpable = 0;
76
e4dc1b14 77static LIST_HEAD(formats);
1da177e4
LT
78static DEFINE_RWLOCK(binfmt_lock);
79
8fc3dc5a 80void __register_binfmt(struct linux_binfmt * fmt, int insert)
1da177e4 81{
8fc3dc5a 82 BUG_ON(!fmt);
92eaa565
ON
83 if (WARN_ON(!fmt->load_binary))
84 return;
1da177e4 85 write_lock(&binfmt_lock);
74641f58
IK
86 insert ? list_add(&fmt->lh, &formats) :
87 list_add_tail(&fmt->lh, &formats);
1da177e4 88 write_unlock(&binfmt_lock);
1da177e4
LT
89}
90
74641f58 91EXPORT_SYMBOL(__register_binfmt);
1da177e4 92
f6b450d4 93void unregister_binfmt(struct linux_binfmt * fmt)
1da177e4 94{
1da177e4 95 write_lock(&binfmt_lock);
e4dc1b14 96 list_del(&fmt->lh);
1da177e4 97 write_unlock(&binfmt_lock);
1da177e4
LT
98}
99
100EXPORT_SYMBOL(unregister_binfmt);
101
102static inline void put_binfmt(struct linux_binfmt * fmt)
103{
104 module_put(fmt->module);
105}
106
90f8572b
EB
107bool path_noexec(const struct path *path)
108{
109 return (path->mnt->mnt_flags & MNT_NOEXEC) ||
110 (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC);
111}
112
69369a70 113#ifdef CONFIG_USELIB
1da177e4
LT
114/*
115 * Note that a shared library must be both readable and executable due to
116 * security reasons.
117 *
118 * Also note that we take the address to load from from the file itself.
119 */
1e7bfb21 120SYSCALL_DEFINE1(uselib, const char __user *, library)
1da177e4 121{
72c2d531 122 struct linux_binfmt *fmt;
964bd183 123 struct file *file;
91a27b2a 124 struct filename *tmp = getname(library);
964bd183 125 int error = PTR_ERR(tmp);
47c805dc
AV
126 static const struct open_flags uselib_flags = {
127 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
62fb4a15 128 .acc_mode = MAY_READ | MAY_EXEC,
f9652e10
AV
129 .intent = LOOKUP_OPEN,
130 .lookup_flags = LOOKUP_FOLLOW,
47c805dc 131 };
964bd183 132
6e8341a1
AV
133 if (IS_ERR(tmp))
134 goto out;
135
f9652e10 136 file = do_filp_open(AT_FDCWD, tmp, &uselib_flags);
6e8341a1
AV
137 putname(tmp);
138 error = PTR_ERR(file);
139 if (IS_ERR(file))
1da177e4
LT
140 goto out;
141
142 error = -EINVAL;
496ad9aa 143 if (!S_ISREG(file_inode(file)->i_mode))
1da177e4
LT
144 goto exit;
145
30524472 146 error = -EACCES;
90f8572b 147 if (path_noexec(&file->f_path))
1da177e4
LT
148 goto exit;
149
2a12a9d7 150 fsnotify_open(file);
6110e3ab 151
1da177e4 152 error = -ENOEXEC;
1da177e4 153
72c2d531
AV
154 read_lock(&binfmt_lock);
155 list_for_each_entry(fmt, &formats, lh) {
156 if (!fmt->load_shlib)
157 continue;
158 if (!try_module_get(fmt->module))
159 continue;
1da177e4 160 read_unlock(&binfmt_lock);
72c2d531
AV
161 error = fmt->load_shlib(file);
162 read_lock(&binfmt_lock);
163 put_binfmt(fmt);
164 if (error != -ENOEXEC)
165 break;
1da177e4 166 }
72c2d531 167 read_unlock(&binfmt_lock);
6e8341a1 168exit:
1da177e4
LT
169 fput(file);
170out:
171 return error;
1da177e4 172}
69369a70 173#endif /* #ifdef CONFIG_USELIB */
1da177e4 174
b6a2fea3 175#ifdef CONFIG_MMU
ae6b585e
ON
176/*
177 * The nascent bprm->mm is not visible until exec_mmap() but it can
178 * use a lot of memory, account these pages in current->mm temporary
179 * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we
180 * change the counter back via acct_arg_size(0).
181 */
0e028465 182static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
3c77f845
ON
183{
184 struct mm_struct *mm = current->mm;
185 long diff = (long)(pages - bprm->vma_pages);
186
187 if (!mm || !diff)
188 return;
189
190 bprm->vma_pages = pages;
3c77f845 191 add_mm_counter(mm, MM_ANONPAGES, diff);
3c77f845
ON
192}
193
0e028465 194static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
b6a2fea3
OW
195 int write)
196{
197 struct page *page;
198 int ret;
9beae1ea 199 unsigned int gup_flags = FOLL_FORCE;
b6a2fea3
OW
200
201#ifdef CONFIG_STACK_GROWSUP
202 if (write) {
d05f3169 203 ret = expand_downwards(bprm->vma, pos);
b6a2fea3
OW
204 if (ret < 0)
205 return NULL;
206 }
207#endif
9beae1ea
LS
208
209 if (write)
210 gup_flags |= FOLL_WRITE;
211
1e987790
DH
212 /*
213 * We are doing an exec(). 'current' is the process
214 * doing the exec and bprm->mm is the new process's mm.
215 */
9beae1ea 216 ret = get_user_pages_remote(current, bprm->mm, pos, 1, gup_flags,
5b56d49f 217 &page, NULL, NULL);
b6a2fea3
OW
218 if (ret <= 0)
219 return NULL;
220
655c16a8
ON
221 if (write)
222 acct_arg_size(bprm, vma_pages(bprm->vma));
b6a2fea3
OW
223
224 return page;
225}
226
227static void put_arg_page(struct page *page)
228{
229 put_page(page);
230}
231
b6a2fea3
OW
232static void free_arg_pages(struct linux_binprm *bprm)
233{
234}
235
236static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
237 struct page *page)
238{
239 flush_cache_page(bprm->vma, pos, page_to_pfn(page));
240}
241
242static int __bprm_mm_init(struct linux_binprm *bprm)
243{
eaccbfa5 244 int err;
b6a2fea3
OW
245 struct vm_area_struct *vma = NULL;
246 struct mm_struct *mm = bprm->mm;
247
490fc053 248 bprm->vma = vma = vm_area_alloc(mm);
b6a2fea3 249 if (!vma)
eaccbfa5 250 return -ENOMEM;
bfd40eaf 251 vma_set_anonymous(vma);
b6a2fea3 252
f268dfe9
MH
253 if (down_write_killable(&mm->mmap_sem)) {
254 err = -EINTR;
255 goto err_free;
256 }
b6a2fea3
OW
257
258 /*
259 * Place the stack at the largest stack address the architecture
260 * supports. Later, we'll move this to an appropriate place. We don't
261 * use STACK_TOP because that can depend on attributes which aren't
262 * configured yet.
263 */
aacb3d17 264 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
b6a2fea3
OW
265 vma->vm_end = STACK_TOP_MAX;
266 vma->vm_start = vma->vm_end - PAGE_SIZE;
d9104d1c 267 vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
3ed75eb8 268 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
462e635e 269
b6a2fea3 270 err = insert_vm_struct(mm, vma);
eaccbfa5 271 if (err)
b6a2fea3 272 goto err;
b6a2fea3
OW
273
274 mm->stack_vm = mm->total_vm = 1;
fe3d197f 275 arch_bprm_mm_init(mm, vma);
b6a2fea3 276 up_write(&mm->mmap_sem);
b6a2fea3 277 bprm->p = vma->vm_end - sizeof(void *);
b6a2fea3 278 return 0;
b6a2fea3 279err:
eaccbfa5 280 up_write(&mm->mmap_sem);
f268dfe9 281err_free:
eaccbfa5 282 bprm->vma = NULL;
3928d4f5 283 vm_area_free(vma);
b6a2fea3
OW
284 return err;
285}
286
287static bool valid_arg_len(struct linux_binprm *bprm, long len)
288{
289 return len <= MAX_ARG_STRLEN;
290}
291
292#else
293
0e028465 294static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
3c77f845
ON
295{
296}
297
0e028465 298static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
b6a2fea3
OW
299 int write)
300{
301 struct page *page;
302
303 page = bprm->page[pos / PAGE_SIZE];
304 if (!page && write) {
305 page = alloc_page(GFP_HIGHUSER|__GFP_ZERO);
306 if (!page)
307 return NULL;
308 bprm->page[pos / PAGE_SIZE] = page;
309 }
310
311 return page;
312}
313
314static void put_arg_page(struct page *page)
315{
316}
317
318static void free_arg_page(struct linux_binprm *bprm, int i)
319{
320 if (bprm->page[i]) {
321 __free_page(bprm->page[i]);
322 bprm->page[i] = NULL;
323 }
324}
325
326static void free_arg_pages(struct linux_binprm *bprm)
327{
328 int i;
329
330 for (i = 0; i < MAX_ARG_PAGES; i++)
331 free_arg_page(bprm, i);
332}
333
334static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
335 struct page *page)
336{
337}
338
339static int __bprm_mm_init(struct linux_binprm *bprm)
340{
341 bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);
342 return 0;
343}
344
345static bool valid_arg_len(struct linux_binprm *bprm, long len)
346{
347 return len <= bprm->p;
348}
349
350#endif /* CONFIG_MMU */
351
352/*
353 * Create a new mm_struct and populate it with a temporary stack
354 * vm_area_struct. We don't have enough context at this point to set the stack
355 * flags, permissions, and offset, so we use temporary values. We'll update
356 * them later in setup_arg_pages().
357 */
9cc64cea 358static int bprm_mm_init(struct linux_binprm *bprm)
b6a2fea3
OW
359{
360 int err;
361 struct mm_struct *mm = NULL;
362
363 bprm->mm = mm = mm_alloc();
364 err = -ENOMEM;
365 if (!mm)
366 goto err;
367
c31dbb14
KC
368 /* Save current stack limit for all calculations made during exec. */
369 task_lock(current->group_leader);
370 bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK];
371 task_unlock(current->group_leader);
372
b6a2fea3
OW
373 err = __bprm_mm_init(bprm);
374 if (err)
375 goto err;
376
377 return 0;
378
379err:
380 if (mm) {
381 bprm->mm = NULL;
382 mmdrop(mm);
383 }
384
385 return err;
386}
387
ba2d0162 388struct user_arg_ptr {
0e028465
ON
389#ifdef CONFIG_COMPAT
390 bool is_compat;
391#endif
392 union {
393 const char __user *const __user *native;
394#ifdef CONFIG_COMPAT
38b983b3 395 const compat_uptr_t __user *compat;
0e028465
ON
396#endif
397 } ptr;
ba2d0162
ON
398};
399
400static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
1d1dbf81 401{
0e028465
ON
402 const char __user *native;
403
404#ifdef CONFIG_COMPAT
405 if (unlikely(argv.is_compat)) {
406 compat_uptr_t compat;
407
408 if (get_user(compat, argv.ptr.compat + nr))
409 return ERR_PTR(-EFAULT);
1d1dbf81 410
0e028465
ON
411 return compat_ptr(compat);
412 }
413#endif
414
415 if (get_user(native, argv.ptr.native + nr))
1d1dbf81
ON
416 return ERR_PTR(-EFAULT);
417
0e028465 418 return native;
1d1dbf81
ON
419}
420
1da177e4
LT
421/*
422 * count() counts the number of strings in array ARGV.
423 */
ba2d0162 424static int count(struct user_arg_ptr argv, int max)
1da177e4
LT
425{
426 int i = 0;
427
0e028465 428 if (argv.ptr.native != NULL) {
1da177e4 429 for (;;) {
1d1dbf81 430 const char __user *p = get_user_arg_ptr(argv, i);
1da177e4 431
1da177e4
LT
432 if (!p)
433 break;
1d1dbf81
ON
434
435 if (IS_ERR(p))
436 return -EFAULT;
437
6d92d4f6 438 if (i >= max)
1da177e4 439 return -E2BIG;
6d92d4f6 440 ++i;
9aea5a65
RM
441
442 if (fatal_signal_pending(current))
443 return -ERESTARTNOHAND;
1da177e4
LT
444 cond_resched();
445 }
446 }
447 return i;
448}
449
655c16a8
ON
450static int prepare_arg_pages(struct linux_binprm *bprm,
451 struct user_arg_ptr argv, struct user_arg_ptr envp)
452{
453 unsigned long limit, ptr_size;
454
455 bprm->argc = count(argv, MAX_ARG_STRINGS);
456 if (bprm->argc < 0)
457 return bprm->argc;
458
459 bprm->envc = count(envp, MAX_ARG_STRINGS);
460 if (bprm->envc < 0)
461 return bprm->envc;
462
463 /*
464 * Limit to 1/4 of the max stack size or 3/4 of _STK_LIM
465 * (whichever is smaller) for the argv+env strings.
466 * This ensures that:
467 * - the remaining binfmt code will not run out of stack space,
468 * - the program will have a reasonable amount of stack left
469 * to work from.
470 */
471 limit = _STK_LIM / 4 * 3;
472 limit = min(limit, bprm->rlim_stack.rlim_cur / 4);
473 /*
474 * We've historically supported up to 32 pages (ARG_MAX)
475 * of argument strings even with small stacks
476 */
477 limit = max_t(unsigned long, limit, ARG_MAX);
478 /*
479 * We must account for the size of all the argv and envp pointers to
480 * the argv and envp strings, since they will also take up space in
481 * the stack. They aren't stored until much later when we can't
482 * signal to the parent that the child has run out of stack space.
483 * Instead, calculate it here so it's possible to fail gracefully.
484 */
485 ptr_size = (bprm->argc + bprm->envc) * sizeof(void *);
486 if (limit <= ptr_size)
487 return -E2BIG;
488 limit -= ptr_size;
489
490 bprm->argmin = bprm->p - limit;
491 return 0;
492}
493
1da177e4 494/*
b6a2fea3
OW
495 * 'copy_strings()' copies argument/environment strings from the old
496 * processes's memory to the new process's stack. The call to get_user_pages()
497 * ensures the destination page is created and not swapped out.
1da177e4 498 */
ba2d0162 499static int copy_strings(int argc, struct user_arg_ptr argv,
75c96f85 500 struct linux_binprm *bprm)
1da177e4
LT
501{
502 struct page *kmapped_page = NULL;
503 char *kaddr = NULL;
b6a2fea3 504 unsigned long kpos = 0;
1da177e4
LT
505 int ret;
506
507 while (argc-- > 0) {
d7627467 508 const char __user *str;
1da177e4
LT
509 int len;
510 unsigned long pos;
511
1d1dbf81
ON
512 ret = -EFAULT;
513 str = get_user_arg_ptr(argv, argc);
514 if (IS_ERR(str))
1da177e4 515 goto out;
1da177e4 516
1d1dbf81
ON
517 len = strnlen_user(str, MAX_ARG_STRLEN);
518 if (!len)
519 goto out;
520
521 ret = -E2BIG;
522 if (!valid_arg_len(bprm, len))
1da177e4 523 goto out;
1da177e4 524
b6a2fea3 525 /* We're going to work our way backwords. */
1da177e4 526 pos = bprm->p;
b6a2fea3
OW
527 str += len;
528 bprm->p -= len;
655c16a8
ON
529#ifdef CONFIG_MMU
530 if (bprm->p < bprm->argmin)
531 goto out;
532#endif
1da177e4
LT
533
534 while (len > 0) {
1da177e4 535 int offset, bytes_to_copy;
1da177e4 536
9aea5a65
RM
537 if (fatal_signal_pending(current)) {
538 ret = -ERESTARTNOHAND;
539 goto out;
540 }
7993bc1f
RM
541 cond_resched();
542
1da177e4 543 offset = pos % PAGE_SIZE;
b6a2fea3
OW
544 if (offset == 0)
545 offset = PAGE_SIZE;
546
547 bytes_to_copy = offset;
548 if (bytes_to_copy > len)
549 bytes_to_copy = len;
550
551 offset -= bytes_to_copy;
552 pos -= bytes_to_copy;
553 str -= bytes_to_copy;
554 len -= bytes_to_copy;
555
556 if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
557 struct page *page;
558
559 page = get_arg_page(bprm, pos, 1);
1da177e4 560 if (!page) {
b6a2fea3 561 ret = -E2BIG;
1da177e4
LT
562 goto out;
563 }
1da177e4 564
b6a2fea3
OW
565 if (kmapped_page) {
566 flush_kernel_dcache_page(kmapped_page);
1da177e4 567 kunmap(kmapped_page);
b6a2fea3
OW
568 put_arg_page(kmapped_page);
569 }
1da177e4
LT
570 kmapped_page = page;
571 kaddr = kmap(kmapped_page);
b6a2fea3
OW
572 kpos = pos & PAGE_MASK;
573 flush_arg_page(bprm, kpos, kmapped_page);
1da177e4 574 }
b6a2fea3 575 if (copy_from_user(kaddr+offset, str, bytes_to_copy)) {
1da177e4
LT
576 ret = -EFAULT;
577 goto out;
578 }
1da177e4
LT
579 }
580 }
581 ret = 0;
582out:
b6a2fea3
OW
583 if (kmapped_page) {
584 flush_kernel_dcache_page(kmapped_page);
1da177e4 585 kunmap(kmapped_page);
b6a2fea3
OW
586 put_arg_page(kmapped_page);
587 }
1da177e4
LT
588 return ret;
589}
590
591/*
592 * Like copy_strings, but get argv and its values from kernel memory.
593 */
ba2d0162 594int copy_strings_kernel(int argc, const char *const *__argv,
d7627467 595 struct linux_binprm *bprm)
1da177e4
LT
596{
597 int r;
598 mm_segment_t oldfs = get_fs();
ba2d0162 599 struct user_arg_ptr argv = {
0e028465 600 .ptr.native = (const char __user *const __user *)__argv,
ba2d0162
ON
601 };
602
1da177e4 603 set_fs(KERNEL_DS);
ba2d0162 604 r = copy_strings(argc, argv, bprm);
1da177e4 605 set_fs(oldfs);
ba2d0162 606
1da177e4
LT
607 return r;
608}
1da177e4
LT
609EXPORT_SYMBOL(copy_strings_kernel);
610
611#ifdef CONFIG_MMU
b6a2fea3 612
1da177e4 613/*
b6a2fea3
OW
614 * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once
615 * the binfmt code determines where the new stack should reside, we shift it to
616 * its final location. The process proceeds as follows:
1da177e4 617 *
b6a2fea3
OW
618 * 1) Use shift to calculate the new vma endpoints.
619 * 2) Extend vma to cover both the old and new ranges. This ensures the
620 * arguments passed to subsequent functions are consistent.
621 * 3) Move vma's page tables to the new range.
622 * 4) Free up any cleared pgd range.
623 * 5) Shrink the vma to cover only the new range.
1da177e4 624 */
b6a2fea3 625static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift)
1da177e4
LT
626{
627 struct mm_struct *mm = vma->vm_mm;
b6a2fea3
OW
628 unsigned long old_start = vma->vm_start;
629 unsigned long old_end = vma->vm_end;
630 unsigned long length = old_end - old_start;
631 unsigned long new_start = old_start - shift;
632 unsigned long new_end = old_end - shift;
d16dfc55 633 struct mmu_gather tlb;
1da177e4 634
b6a2fea3 635 BUG_ON(new_start > new_end);
1da177e4 636
b6a2fea3
OW
637 /*
638 * ensure there are no vmas between where we want to go
639 * and where we are
640 */
641 if (vma != find_vma(mm, new_start))
642 return -EFAULT;
643
644 /*
645 * cover the whole range: [new_start, old_end)
646 */
5beb4930
RR
647 if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL))
648 return -ENOMEM;
b6a2fea3
OW
649
650 /*
651 * move the page tables downwards, on failure we rely on
652 * process cleanup to remove whatever mess we made.
653 */
654 if (length != move_page_tables(vma, old_start,
38a76013 655 vma, new_start, length, false))
b6a2fea3
OW
656 return -ENOMEM;
657
658 lru_add_drain();
2b047252 659 tlb_gather_mmu(&tlb, mm, old_start, old_end);
b6a2fea3
OW
660 if (new_end > old_start) {
661 /*
662 * when the old and new regions overlap clear from new_end.
663 */
d16dfc55 664 free_pgd_range(&tlb, new_end, old_end, new_end,
6ee8630e 665 vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
b6a2fea3
OW
666 } else {
667 /*
668 * otherwise, clean from old_start; this is done to not touch
669 * the address space in [new_end, old_start) some architectures
670 * have constraints on va-space that make this illegal (IA64) -
671 * for the others its just a little faster.
672 */
d16dfc55 673 free_pgd_range(&tlb, old_start, old_end, new_end,
6ee8630e 674 vma->vm_next ? vma->vm_next->vm_start : USER_PGTABLES_CEILING);
1da177e4 675 }
2b047252 676 tlb_finish_mmu(&tlb, old_start, old_end);
b6a2fea3
OW
677
678 /*
5beb4930 679 * Shrink the vma to just the new range. Always succeeds.
b6a2fea3
OW
680 */
681 vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL);
682
683 return 0;
1da177e4
LT
684}
685
b6a2fea3
OW
686/*
687 * Finalizes the stack vm_area_struct. The flags and permissions are updated,
688 * the stack is optionally relocated, and some extra space is added.
689 */
1da177e4
LT
690int setup_arg_pages(struct linux_binprm *bprm,
691 unsigned long stack_top,
692 int executable_stack)
693{
b6a2fea3
OW
694 unsigned long ret;
695 unsigned long stack_shift;
1da177e4 696 struct mm_struct *mm = current->mm;
b6a2fea3
OW
697 struct vm_area_struct *vma = bprm->vma;
698 struct vm_area_struct *prev = NULL;
699 unsigned long vm_flags;
700 unsigned long stack_base;
803bf5ec
MN
701 unsigned long stack_size;
702 unsigned long stack_expand;
703 unsigned long rlim_stack;
1da177e4
LT
704
705#ifdef CONFIG_STACK_GROWSUP
d71f290b 706 /* Limit stack size */
c31dbb14 707 stack_base = bprm->rlim_stack.rlim_max;
d71f290b
JH
708 if (stack_base > STACK_SIZE_MAX)
709 stack_base = STACK_SIZE_MAX;
1da177e4 710
d045c77c
HD
711 /* Add space for stack randomization. */
712 stack_base += (STACK_RND_MASK << PAGE_SHIFT);
713
b6a2fea3
OW
714 /* Make sure we didn't let the argument array grow too large. */
715 if (vma->vm_end - vma->vm_start > stack_base)
716 return -ENOMEM;
1da177e4 717
b6a2fea3 718 stack_base = PAGE_ALIGN(stack_top - stack_base);
1da177e4 719
b6a2fea3
OW
720 stack_shift = vma->vm_start - stack_base;
721 mm->arg_start = bprm->p - stack_shift;
722 bprm->p = vma->vm_end - stack_shift;
1da177e4 723#else
b6a2fea3
OW
724 stack_top = arch_align_stack(stack_top);
725 stack_top = PAGE_ALIGN(stack_top);
1b528181
RM
726
727 if (unlikely(stack_top < mmap_min_addr) ||
728 unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr))
729 return -ENOMEM;
730
b6a2fea3
OW
731 stack_shift = vma->vm_end - stack_top;
732
733 bprm->p -= stack_shift;
1da177e4 734 mm->arg_start = bprm->p;
1da177e4
LT
735#endif
736
1da177e4 737 if (bprm->loader)
b6a2fea3
OW
738 bprm->loader -= stack_shift;
739 bprm->exec -= stack_shift;
1da177e4 740
f268dfe9
MH
741 if (down_write_killable(&mm->mmap_sem))
742 return -EINTR;
743
96a8e13e 744 vm_flags = VM_STACK_FLAGS;
b6a2fea3
OW
745
746 /*
747 * Adjust stack execute permissions; explicitly enable for
748 * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone
749 * (arch default) otherwise.
750 */
751 if (unlikely(executable_stack == EXSTACK_ENABLE_X))
752 vm_flags |= VM_EXEC;
753 else if (executable_stack == EXSTACK_DISABLE_X)
754 vm_flags &= ~VM_EXEC;
755 vm_flags |= mm->def_flags;
a8bef8ff 756 vm_flags |= VM_STACK_INCOMPLETE_SETUP;
b6a2fea3
OW
757
758 ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end,
759 vm_flags);
760 if (ret)
761 goto out_unlock;
762 BUG_ON(prev != vma);
763
764 /* Move stack pages down in memory. */
765 if (stack_shift) {
766 ret = shift_arg_pages(vma, stack_shift);
fc63cf23
AB
767 if (ret)
768 goto out_unlock;
1da177e4
LT
769 }
770
a8bef8ff
MG
771 /* mprotect_fixup is overkill to remove the temporary stack flags */
772 vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP;
773
5ef097dd 774 stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */
803bf5ec
MN
775 stack_size = vma->vm_end - vma->vm_start;
776 /*
777 * Align this down to a page boundary as expand_stack
778 * will align it up.
779 */
c31dbb14 780 rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK;
b6a2fea3 781#ifdef CONFIG_STACK_GROWSUP
803bf5ec
MN
782 if (stack_size + stack_expand > rlim_stack)
783 stack_base = vma->vm_start + rlim_stack;
784 else
785 stack_base = vma->vm_end + stack_expand;
b6a2fea3 786#else
803bf5ec
MN
787 if (stack_size + stack_expand > rlim_stack)
788 stack_base = vma->vm_end - rlim_stack;
789 else
790 stack_base = vma->vm_start - stack_expand;
b6a2fea3 791#endif
3af9e859 792 current->mm->start_stack = bprm->p;
b6a2fea3
OW
793 ret = expand_stack(vma, stack_base);
794 if (ret)
795 ret = -EFAULT;
796
797out_unlock:
1da177e4 798 up_write(&mm->mmap_sem);
fc63cf23 799 return ret;
1da177e4 800}
1da177e4
LT
801EXPORT_SYMBOL(setup_arg_pages);
802
7e7ec6a9
NP
803#else
804
805/*
806 * Transfer the program arguments and environment from the holding pages
807 * onto the stack. The provided stack pointer is adjusted accordingly.
808 */
809int transfer_args_to_stack(struct linux_binprm *bprm,
810 unsigned long *sp_location)
811{
812 unsigned long index, stop, sp;
813 int ret = 0;
814
815 stop = bprm->p >> PAGE_SHIFT;
816 sp = *sp_location;
817
818 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
819 unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;
820 char *src = kmap(bprm->page[index]) + offset;
821 sp -= PAGE_SIZE - offset;
822 if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0)
823 ret = -EFAULT;
824 kunmap(bprm->page[index]);
825 if (ret)
826 goto out;
827 }
828
829 *sp_location = sp;
830
831out:
832 return ret;
833}
834EXPORT_SYMBOL(transfer_args_to_stack);
835
1da177e4
LT
836#endif /* CONFIG_MMU */
837
51f39a1f 838static struct file *do_open_execat(int fd, struct filename *name, int flags)
1da177e4 839{
1da177e4 840 struct file *file;
e56b6a5d 841 int err;
51f39a1f 842 struct open_flags open_exec_flags = {
47c805dc 843 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
62fb4a15 844 .acc_mode = MAY_EXEC,
f9652e10
AV
845 .intent = LOOKUP_OPEN,
846 .lookup_flags = LOOKUP_FOLLOW,
47c805dc 847 };
1da177e4 848
51f39a1f
DD
849 if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
850 return ERR_PTR(-EINVAL);
851 if (flags & AT_SYMLINK_NOFOLLOW)
852 open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW;
853 if (flags & AT_EMPTY_PATH)
854 open_exec_flags.lookup_flags |= LOOKUP_EMPTY;
855
856 file = do_filp_open(fd, name, &open_exec_flags);
6e8341a1 857 if (IS_ERR(file))
e56b6a5d
CH
858 goto out;
859
860 err = -EACCES;
496ad9aa 861 if (!S_ISREG(file_inode(file)->i_mode))
6e8341a1 862 goto exit;
e56b6a5d 863
90f8572b 864 if (path_noexec(&file->f_path))
6e8341a1 865 goto exit;
e56b6a5d
CH
866
867 err = deny_write_access(file);
6e8341a1
AV
868 if (err)
869 goto exit;
1da177e4 870
51f39a1f
DD
871 if (name->name[0] != '\0')
872 fsnotify_open(file);
873
6e8341a1 874out:
e56b6a5d
CH
875 return file;
876
6e8341a1
AV
877exit:
878 fput(file);
e56b6a5d
CH
879 return ERR_PTR(err);
880}
c4ad8f98
LT
881
882struct file *open_exec(const char *name)
883{
51689104
PM
884 struct filename *filename = getname_kernel(name);
885 struct file *f = ERR_CAST(filename);
886
887 if (!IS_ERR(filename)) {
888 f = do_open_execat(AT_FDCWD, filename, 0);
889 putname(filename);
890 }
891 return f;
c4ad8f98 892}
1da177e4
LT
893EXPORT_SYMBOL(open_exec);
894
b44a7dfc 895int kernel_read_file(struct file *file, void **buf, loff_t *size,
bc8ca5b9 896 loff_t max_size, enum kernel_read_file_id id)
b44a7dfc
MZ
897{
898 loff_t i_size, pos;
899 ssize_t bytes = 0;
900 int ret;
901
902 if (!S_ISREG(file_inode(file)->i_mode) || max_size < 0)
903 return -EINVAL;
904
7bd698b3 905 ret = deny_write_access(file);
39eeb4fb
MZ
906 if (ret)
907 return ret;
908
7bd698b3 909 ret = security_kernel_read_file(file, id);
39d637af 910 if (ret)
7bd698b3 911 goto out;
39d637af 912
b44a7dfc 913 i_size = i_size_read(file_inode(file));
39d637af
DK
914 if (i_size <= 0) {
915 ret = -EINVAL;
916 goto out;
917 }
691115c3
EB
918 if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) {
919 ret = -EFBIG;
920 goto out;
921 }
b44a7dfc 922
a098ecd2
SB
923 if (id != READING_FIRMWARE_PREALLOC_BUFFER)
924 *buf = vmalloc(i_size);
39d637af
DK
925 if (!*buf) {
926 ret = -ENOMEM;
927 goto out;
928 }
b44a7dfc
MZ
929
930 pos = 0;
931 while (pos < i_size) {
bdd1d2d3 932 bytes = kernel_read(file, *buf + pos, i_size - pos, &pos);
b44a7dfc
MZ
933 if (bytes < 0) {
934 ret = bytes;
935 goto out;
936 }
937
938 if (bytes == 0)
939 break;
b44a7dfc
MZ
940 }
941
942 if (pos != i_size) {
943 ret = -EIO;
39d637af 944 goto out_free;
b44a7dfc
MZ
945 }
946
bc8ca5b9 947 ret = security_kernel_post_read_file(file, *buf, i_size, id);
b44a7dfc
MZ
948 if (!ret)
949 *size = pos;
950
39d637af 951out_free:
b44a7dfc 952 if (ret < 0) {
a098ecd2
SB
953 if (id != READING_FIRMWARE_PREALLOC_BUFFER) {
954 vfree(*buf);
955 *buf = NULL;
956 }
b44a7dfc 957 }
39d637af
DK
958
959out:
960 allow_write_access(file);
b44a7dfc
MZ
961 return ret;
962}
963EXPORT_SYMBOL_GPL(kernel_read_file);
964
711aab1d 965int kernel_read_file_from_path(const char *path, void **buf, loff_t *size,
09596b94
MZ
966 loff_t max_size, enum kernel_read_file_id id)
967{
968 struct file *file;
969 int ret;
970
971 if (!path || !*path)
972 return -EINVAL;
973
974 file = filp_open(path, O_RDONLY, 0);
975 if (IS_ERR(file))
976 return PTR_ERR(file);
977
978 ret = kernel_read_file(file, buf, size, max_size, id);
979 fput(file);
980 return ret;
981}
982EXPORT_SYMBOL_GPL(kernel_read_file_from_path);
983
b844f0ec
MZ
984int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size,
985 enum kernel_read_file_id id)
986{
987 struct fd f = fdget(fd);
988 int ret = -EBADF;
989
990 if (!f.file)
991 goto out;
992
993 ret = kernel_read_file(f.file, buf, size, max_size, id);
994out:
995 fdput(f);
996 return ret;
997}
998EXPORT_SYMBOL_GPL(kernel_read_file_from_fd);
999
3dc20cb2
AV
1000ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
1001{
ec695579 1002 ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
3dc20cb2
AV
1003 if (res > 0)
1004 flush_icache_range(addr, addr + len);
1005 return res;
1006}
1007EXPORT_SYMBOL(read_code);
1008
1da177e4
LT
1009static int exec_mmap(struct mm_struct *mm)
1010{
1011 struct task_struct *tsk;
615d6e87 1012 struct mm_struct *old_mm, *active_mm;
1da177e4
LT
1013
1014 /* Notify parent that we're no longer interested in the old VM */
1015 tsk = current;
1016 old_mm = current->mm;
1017 mm_release(tsk, old_mm);
1018
1019 if (old_mm) {
4fe7efdb 1020 sync_mm_rss(old_mm);
1da177e4
LT
1021 /*
1022 * Make sure that if there is a core dump in progress
1023 * for the old mm, we get out and die instead of going
1024 * through with the exec. We must hold mmap_sem around
999d9fc1 1025 * checking core_state and changing tsk->mm.
1da177e4
LT
1026 */
1027 down_read(&old_mm->mmap_sem);
999d9fc1 1028 if (unlikely(old_mm->core_state)) {
1da177e4
LT
1029 up_read(&old_mm->mmap_sem);
1030 return -EINTR;
1031 }
1032 }
1033 task_lock(tsk);
1034 active_mm = tsk->active_mm;
1035 tsk->mm = mm;
1036 tsk->active_mm = mm;
1037 activate_mm(active_mm, mm);
615d6e87
DB
1038 tsk->mm->vmacache_seqnum = 0;
1039 vmacache_flush(tsk);
1da177e4 1040 task_unlock(tsk);
1da177e4
LT
1041 if (old_mm) {
1042 up_read(&old_mm->mmap_sem);
7dddb12c 1043 BUG_ON(active_mm != old_mm);
701085b2 1044 setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm);
31a78f23 1045 mm_update_next_owner(old_mm);
1da177e4
LT
1046 mmput(old_mm);
1047 return 0;
1048 }
1049 mmdrop(active_mm);
1050 return 0;
1051}
1052
1053/*
1054 * This function makes sure the current process has its own signal table,
1055 * so that flush_signal_handlers can later reset the handlers without
1056 * disturbing other processes. (Other processes might share the signal
1057 * table via the CLONE_SIGHAND option to clone().)
1058 */
858119e1 1059static int de_thread(struct task_struct *tsk)
1da177e4
LT
1060{
1061 struct signal_struct *sig = tsk->signal;
b2c903b8 1062 struct sighand_struct *oldsighand = tsk->sighand;
1da177e4 1063 spinlock_t *lock = &oldsighand->siglock;
1da177e4 1064
aafe6c2a 1065 if (thread_group_empty(tsk))
1da177e4
LT
1066 goto no_thread_group;
1067
1068 /*
1069 * Kill all other threads in the thread group.
1da177e4 1070 */
1da177e4 1071 spin_lock_irq(lock);
ed5d2cac 1072 if (signal_group_exit(sig)) {
1da177e4
LT
1073 /*
1074 * Another group action in progress, just
1075 * return so that the signal is processed.
1076 */
1077 spin_unlock_irq(lock);
1da177e4
LT
1078 return -EAGAIN;
1079 }
d344193a 1080
ed5d2cac 1081 sig->group_exit_task = tsk;
d344193a
ON
1082 sig->notify_count = zap_other_threads(tsk);
1083 if (!thread_group_leader(tsk))
1084 sig->notify_count--;
1da177e4 1085
d344193a 1086 while (sig->notify_count) {
d5bbd43d 1087 __set_current_state(TASK_KILLABLE);
1da177e4 1088 spin_unlock_irq(lock);
a72173ec 1089 schedule();
08d405c8 1090 if (__fatal_signal_pending(tsk))
d5bbd43d 1091 goto killed;
1da177e4
LT
1092 spin_lock_irq(lock);
1093 }
1da177e4
LT
1094 spin_unlock_irq(lock);
1095
1096 /*
1097 * At this point all other threads have exited, all we have to
1098 * do is to wait for the thread group leader to become inactive,
1099 * and to assume its PID:
1100 */
aafe6c2a 1101 if (!thread_group_leader(tsk)) {
8187926b 1102 struct task_struct *leader = tsk->group_leader;
6db840fa 1103
6db840fa 1104 for (;;) {
780de9dd 1105 cgroup_threadgroup_change_begin(tsk);
6db840fa 1106 write_lock_irq(&tasklist_lock);
dfcce791
KT
1107 /*
1108 * Do this under tasklist_lock to ensure that
1109 * exit_notify() can't miss ->group_exit_task
1110 */
1111 sig->notify_count = -1;
6db840fa
ON
1112 if (likely(leader->exit_state))
1113 break;
d5bbd43d 1114 __set_current_state(TASK_KILLABLE);
6db840fa 1115 write_unlock_irq(&tasklist_lock);
780de9dd 1116 cgroup_threadgroup_change_end(tsk);
a72173ec 1117 schedule();
08d405c8 1118 if (__fatal_signal_pending(tsk))
d5bbd43d 1119 goto killed;
6db840fa 1120 }
1da177e4 1121
f5e90281
RM
1122 /*
1123 * The only record we have of the real-time age of a
1124 * process, regardless of execs it's done, is start_time.
1125 * All the past CPU time is accumulated in signal_struct
1126 * from sister threads now dead. But in this non-leader
1127 * exec, nothing survives from the original leader thread,
1128 * whose birth marks the true age of this process now.
1129 * When we take on its identity by switching to its PID, we
1130 * also take its birthdate (always earlier than our own).
1131 */
aafe6c2a 1132 tsk->start_time = leader->start_time;
266b7a02 1133 tsk->real_start_time = leader->real_start_time;
f5e90281 1134
bac0abd6
PE
1135 BUG_ON(!same_thread_group(leader, tsk));
1136 BUG_ON(has_group_leader_pid(tsk));
1da177e4
LT
1137 /*
1138 * An exec() starts a new thread group with the
1139 * TGID of the previous thread group. Rehash the
1140 * two threads with a switched PID, and release
1141 * the former thread group leader:
1142 */
d73d6529
EB
1143
1144 /* Become a process group leader with the old leader's pid.
c18258c6
EB
1145 * The old leader becomes a thread of the this thread group.
1146 * Note: The old leader also uses this pid until release_task
d73d6529
EB
1147 * is called. Odd but simple and correct.
1148 */
aafe6c2a 1149 tsk->pid = leader->pid;
3f418548 1150 change_pid(tsk, PIDTYPE_PID, task_pid(leader));
6883f81a 1151 transfer_pid(leader, tsk, PIDTYPE_TGID);
aafe6c2a
EB
1152 transfer_pid(leader, tsk, PIDTYPE_PGID);
1153 transfer_pid(leader, tsk, PIDTYPE_SID);
9cd80bbb 1154
aafe6c2a 1155 list_replace_rcu(&leader->tasks, &tsk->tasks);
9cd80bbb 1156 list_replace_init(&leader->sibling, &tsk->sibling);
1da177e4 1157
aafe6c2a
EB
1158 tsk->group_leader = tsk;
1159 leader->group_leader = tsk;
de12a787 1160
aafe6c2a 1161 tsk->exit_signal = SIGCHLD;
087806b1 1162 leader->exit_signal = -1;
962b564c
ON
1163
1164 BUG_ON(leader->exit_state != EXIT_ZOMBIE);
1165 leader->exit_state = EXIT_DEAD;
eac1b5e5
ON
1166
1167 /*
1168 * We are going to release_task()->ptrace_unlink() silently,
1169 * the tracer can sleep in do_wait(). EXIT_DEAD guarantees
1170 * the tracer wont't block again waiting for this thread.
1171 */
1172 if (unlikely(leader->ptrace))
1173 __wake_up_parent(leader, leader->parent);
1da177e4 1174 write_unlock_irq(&tasklist_lock);
780de9dd 1175 cgroup_threadgroup_change_end(tsk);
8187926b
ON
1176
1177 release_task(leader);
ed5d2cac 1178 }
1da177e4 1179
6db840fa
ON
1180 sig->group_exit_task = NULL;
1181 sig->notify_count = 0;
1da177e4
LT
1182
1183no_thread_group:
e6368253
ON
1184 /* we have changed execution domain */
1185 tsk->exit_signal = SIGCHLD;
1186
baa73d9e 1187#ifdef CONFIG_POSIX_TIMERS
1da177e4 1188 exit_itimers(sig);
cbaffba1 1189 flush_itimer_signals();
baa73d9e 1190#endif
329f7dba 1191
b2c903b8
ON
1192 if (atomic_read(&oldsighand->count) != 1) {
1193 struct sighand_struct *newsighand;
1da177e4 1194 /*
b2c903b8
ON
1195 * This ->sighand is shared with the CLONE_SIGHAND
1196 * but not CLONE_THREAD task, switch to the new one.
1da177e4 1197 */
b2c903b8
ON
1198 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
1199 if (!newsighand)
1200 return -ENOMEM;
1201
1da177e4
LT
1202 atomic_set(&newsighand->count, 1);
1203 memcpy(newsighand->action, oldsighand->action,
1204 sizeof(newsighand->action));
1205
1206 write_lock_irq(&tasklist_lock);
1207 spin_lock(&oldsighand->siglock);
aafe6c2a 1208 rcu_assign_pointer(tsk->sighand, newsighand);
1da177e4
LT
1209 spin_unlock(&oldsighand->siglock);
1210 write_unlock_irq(&tasklist_lock);
1211
fba2afaa 1212 __cleanup_sighand(oldsighand);
1da177e4
LT
1213 }
1214
aafe6c2a 1215 BUG_ON(!thread_group_leader(tsk));
1da177e4 1216 return 0;
d5bbd43d
ON
1217
1218killed:
1219 /* protects against exit_notify() and __exit_signal() */
1220 read_lock(&tasklist_lock);
1221 sig->group_exit_task = NULL;
1222 sig->notify_count = 0;
1223 read_unlock(&tasklist_lock);
1224 return -EAGAIN;
1da177e4 1225}
0840a90d 1226
3756f640 1227char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk)
1da177e4 1228{
1da177e4 1229 task_lock(tsk);
3756f640 1230 strncpy(buf, tsk->comm, buf_size);
1da177e4 1231 task_unlock(tsk);
59714d65 1232 return buf;
1da177e4 1233}
3756f640 1234EXPORT_SYMBOL_GPL(__get_task_comm);
1da177e4 1235
6a6d27de
AV
1236/*
1237 * These functions flushes out all traces of the currently running executable
1238 * so that a new one can be started
1239 */
1240
82b89778 1241void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
1da177e4
LT
1242{
1243 task_lock(tsk);
43d2b113 1244 trace_task_rename(tsk, buf);
1da177e4
LT
1245 strlcpy(tsk->comm, buf, sizeof(tsk->comm));
1246 task_unlock(tsk);
82b89778 1247 perf_event_comm(tsk, exec);
1da177e4
LT
1248}
1249
a9208e42
KC
1250/*
1251 * Calling this is the point of no return. None of the failures will be
1252 * seen by userspace since either the process is already taking a fatal
1253 * signal (via de_thread() or coredump), or will have SEGV raised
1254 * (after exec_mmap()) by search_binary_handlers (see below).
1255 */
1da177e4
LT
1256int flush_old_exec(struct linux_binprm * bprm)
1257{
221af7f8 1258 int retval;
1da177e4
LT
1259
1260 /*
1261 * Make sure we have a private signal table and that
1262 * we are unassociated from the previous thread group.
1263 */
1264 retval = de_thread(current);
1265 if (retval)
1266 goto out;
1267
6e399cd1
DB
1268 /*
1269 * Must be called _before_ exec_mmap() as bprm->mm is
1270 * not visibile until then. This also enables the update
1271 * to be lockless.
1272 */
925d1c40 1273 set_mm_exe_file(bprm->mm, bprm->file);
6e399cd1 1274
1da177e4
LT
1275 /*
1276 * Release all of the old mmap stuff
1277 */
3c77f845 1278 acct_arg_size(bprm, 0);
1da177e4
LT
1279 retval = exec_mmap(bprm->mm);
1280 if (retval)
fd8328be 1281 goto out;
1da177e4 1282
a9208e42
KC
1283 /*
1284 * After clearing bprm->mm (to mark that current is using the
1285 * prepared mm now), we have nothing left of the original
1286 * process. If anything from here on returns an error, the check
1287 * in search_binary_handler() will SEGV current.
1288 */
1289 bprm->mm = NULL;
7ab02af4 1290
dac853ae 1291 set_fs(USER_DS);
b88fae64
ZY
1292 current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
1293 PF_NOFREEZE | PF_NO_SETAFFINITY);
7ab02af4
LT
1294 flush_thread();
1295 current->personality &= ~bprm->per_clear;
1296
613cc2b6
AS
1297 /*
1298 * We have to apply CLOEXEC before we change whether the process is
1299 * dumpable (in setup_new_exec) to avoid a race with a process in userspace
1300 * trying to access the should-be-closed file descriptors of a process
1301 * undergoing exec(2).
1302 */
1303 do_close_on_exec(current->files);
221af7f8
LT
1304 return 0;
1305
1306out:
1307 return retval;
1308}
1309EXPORT_SYMBOL(flush_old_exec);
1310
1b5d783c
AV
1311void would_dump(struct linux_binprm *bprm, struct file *file)
1312{
f84df2a6
EB
1313 struct inode *inode = file_inode(file);
1314 if (inode_permission(inode, MAY_READ) < 0) {
1315 struct user_namespace *old, *user_ns;
1b5d783c 1316 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
f84df2a6
EB
1317
1318 /* Ensure mm->user_ns contains the executable */
1319 user_ns = old = bprm->mm->user_ns;
1320 while ((user_ns != &init_user_ns) &&
1321 !privileged_wrt_inode_uidgid(user_ns, inode))
1322 user_ns = user_ns->parent;
1323
1324 if (old != user_ns) {
1325 bprm->mm->user_ns = get_user_ns(user_ns);
1326 put_user_ns(old);
1327 }
1328 }
1b5d783c
AV
1329}
1330EXPORT_SYMBOL(would_dump);
1331
221af7f8
LT
1332void setup_new_exec(struct linux_binprm * bprm)
1333{
46d98eb4
KC
1334 /*
1335 * Once here, prepare_binrpm() will not be called any more, so
1336 * the final state of setuid/setgid/fscaps can be merged into the
1337 * secureexec flag.
1338 */
1339 bprm->secureexec |= bprm->cap_elevated;
1340
64701dee 1341 if (bprm->secureexec) {
fe8993b3
KC
1342 /* Make sure parent cannot signal privileged process. */
1343 current->pdeath_signal = 0;
1344
64701dee
KC
1345 /*
1346 * For secureexec, reset the stack limit to sane default to
1347 * avoid bad behavior from the prior rlimits. This has to
1348 * happen before arch_pick_mmap_layout(), which examines
1349 * RLIMIT_STACK, but after the point of no return to avoid
779f4e1c 1350 * needing to clean up the change on failure.
64701dee 1351 */
c31dbb14
KC
1352 if (bprm->rlim_stack.rlim_cur > _STK_LIM)
1353 bprm->rlim_stack.rlim_cur = _STK_LIM;
64701dee
KC
1354 }
1355
c31dbb14 1356 arch_pick_mmap_layout(current->mm, &bprm->rlim_stack);
1da177e4 1357
1da177e4
LT
1358 current->sas_ss_sp = current->sas_ss_size = 0;
1359
e816c201
KC
1360 /*
1361 * Figure out dumpability. Note that this checking only of current
1362 * is wrong, but userspace depends on it. This should be testing
1363 * bprm->secureexec instead.
1364 */
473d8963 1365 if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
e816c201
KC
1366 !(uid_eq(current_euid(), current_uid()) &&
1367 gid_eq(current_egid(), current_gid())))
6c5d5238 1368 set_dumpable(current->mm, suid_dumpable);
473d8963
KC
1369 else
1370 set_dumpable(current->mm, SUID_DUMP_USER);
d6e71144 1371
e9ea1e7f 1372 arch_setup_new_exec();
e041e328 1373 perf_event_exec();
82b89778 1374 __set_task_comm(current, kbasename(bprm->filename), true);
1da177e4 1375
0551fbd2
BH
1376 /* Set the new mm task size. We have to do that late because it may
1377 * depend on TIF_32BIT which is only updated in flush_thread() on
1378 * some architectures like powerpc
1379 */
1380 current->mm->task_size = TASK_SIZE;
1381
1da177e4
LT
1382 /* An exec changes our domain. We are no longer part of the thread
1383 group */
1da177e4 1384 current->self_exec_id++;
1da177e4 1385 flush_signal_handlers(current, 0);
1da177e4 1386}
221af7f8 1387EXPORT_SYMBOL(setup_new_exec);
1da177e4 1388
b8383831
KC
1389/* Runs immediately before start_thread() takes over. */
1390void finalize_exec(struct linux_binprm *bprm)
1391{
c31dbb14
KC
1392 /* Store any stack rlimit changes before starting thread. */
1393 task_lock(current->group_leader);
1394 current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack;
1395 task_unlock(current->group_leader);
b8383831
KC
1396}
1397EXPORT_SYMBOL(finalize_exec);
1398
a2a8474c
ON
1399/*
1400 * Prepare credentials and lock ->cred_guard_mutex.
1401 * install_exec_creds() commits the new creds and drops the lock.
1402 * Or, if exec fails before, free_bprm() should release ->cred and
1403 * and unlock.
1404 */
4addd264 1405static int prepare_bprm_creds(struct linux_binprm *bprm)
a2a8474c 1406{
9b1bf12d 1407 if (mutex_lock_interruptible(&current->signal->cred_guard_mutex))
a2a8474c
ON
1408 return -ERESTARTNOINTR;
1409
1410 bprm->cred = prepare_exec_creds();
1411 if (likely(bprm->cred))
1412 return 0;
1413
9b1bf12d 1414 mutex_unlock(&current->signal->cred_guard_mutex);
a2a8474c
ON
1415 return -ENOMEM;
1416}
1417
c4ad8f98 1418static void free_bprm(struct linux_binprm *bprm)
a2a8474c
ON
1419{
1420 free_arg_pages(bprm);
1421 if (bprm->cred) {
9b1bf12d 1422 mutex_unlock(&current->signal->cred_guard_mutex);
a2a8474c
ON
1423 abort_creds(bprm->cred);
1424 }
63e46b95
ON
1425 if (bprm->file) {
1426 allow_write_access(bprm->file);
1427 fput(bprm->file);
1428 }
b66c5984
KC
1429 /* If a binfmt changed the interp, free it. */
1430 if (bprm->interp != bprm->filename)
1431 kfree(bprm->interp);
a2a8474c
ON
1432 kfree(bprm);
1433}
1434
c2315c18 1435int bprm_change_interp(const char *interp, struct linux_binprm *bprm)
b66c5984
KC
1436{
1437 /* If a binfmt changed the interp, free it first. */
1438 if (bprm->interp != bprm->filename)
1439 kfree(bprm->interp);
1440 bprm->interp = kstrdup(interp, GFP_KERNEL);
1441 if (!bprm->interp)
1442 return -ENOMEM;
1443 return 0;
1444}
1445EXPORT_SYMBOL(bprm_change_interp);
1446
a6f76f23
DH
1447/*
1448 * install the new credentials for this executable
1449 */
1450void install_exec_creds(struct linux_binprm *bprm)
1451{
1452 security_bprm_committing_creds(bprm);
1453
1454 commit_creds(bprm->cred);
1455 bprm->cred = NULL;
2976b10f
SE
1456
1457 /*
1458 * Disable monitoring for regular users
1459 * when executing setuid binaries. Must
1460 * wait until new credentials are committed
1461 * by commit_creds() above
1462 */
1463 if (get_dumpable(current->mm) != SUID_DUMP_USER)
1464 perf_event_exit_task(current);
a2a8474c
ON
1465 /*
1466 * cred_guard_mutex must be held at least to this point to prevent
a6f76f23 1467 * ptrace_attach() from altering our determination of the task's
a2a8474c
ON
1468 * credentials; any time after this it may be unlocked.
1469 */
a6f76f23 1470 security_bprm_committed_creds(bprm);
9b1bf12d 1471 mutex_unlock(&current->signal->cred_guard_mutex);
a6f76f23
DH
1472}
1473EXPORT_SYMBOL(install_exec_creds);
1474
1475/*
1476 * determine how safe it is to execute the proposed program
9b1bf12d 1477 * - the caller must hold ->cred_guard_mutex to protect against
c2e1f2e3 1478 * PTRACE_ATTACH or seccomp thread-sync
a6f76f23 1479 */
9e00cdb0 1480static void check_unsafe_exec(struct linux_binprm *bprm)
a6f76f23 1481{
0bf2f3ae 1482 struct task_struct *p = current, *t;
f1191b50 1483 unsigned n_fs;
a6f76f23 1484
9227dd2a
EB
1485 if (p->ptrace)
1486 bprm->unsafe |= LSM_UNSAFE_PTRACE;
a6f76f23 1487
259e5e6c
AL
1488 /*
1489 * This isn't strictly necessary, but it makes it harder for LSMs to
1490 * mess up.
1491 */
1d4457f9 1492 if (task_no_new_privs(current))
259e5e6c
AL
1493 bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
1494
83f62a2e 1495 t = p;
0bf2f3ae 1496 n_fs = 1;
2a4419b5 1497 spin_lock(&p->fs->lock);
437f7fdb 1498 rcu_read_lock();
83f62a2e 1499 while_each_thread(p, t) {
0bf2f3ae
DH
1500 if (t->fs == p->fs)
1501 n_fs++;
0bf2f3ae 1502 }
437f7fdb 1503 rcu_read_unlock();
0bf2f3ae 1504
9e00cdb0 1505 if (p->fs->users > n_fs)
a6f76f23 1506 bprm->unsafe |= LSM_UNSAFE_SHARE;
9e00cdb0
ON
1507 else
1508 p->fs->in_exec = 1;
2a4419b5 1509 spin_unlock(&p->fs->lock);
a6f76f23
DH
1510}
1511
8b01fc86
JH
1512static void bprm_fill_uid(struct linux_binprm *bprm)
1513{
1514 struct inode *inode;
1515 unsigned int mode;
1516 kuid_t uid;
1517 kgid_t gid;
1518
cb6fd68f
KC
1519 /*
1520 * Since this can be called multiple times (via prepare_binprm),
1521 * we must clear any previous work done when setting set[ug]id
1522 * bits from any earlier bprm->file uses (for example when run
1523 * first for a setuid script then again for its interpreter).
1524 */
8b01fc86
JH
1525 bprm->cred->euid = current_euid();
1526 bprm->cred->egid = current_egid();
1527
380cf5ba 1528 if (!mnt_may_suid(bprm->file->f_path.mnt))
8b01fc86
JH
1529 return;
1530
1531 if (task_no_new_privs(current))
1532 return;
1533
fea6d2a6 1534 inode = bprm->file->f_path.dentry->d_inode;
8b01fc86
JH
1535 mode = READ_ONCE(inode->i_mode);
1536 if (!(mode & (S_ISUID|S_ISGID)))
1537 return;
1538
1539 /* Be careful if suid/sgid is set */
5955102c 1540 inode_lock(inode);
8b01fc86
JH
1541
1542 /* reload atomically mode/uid/gid now that lock held */
1543 mode = inode->i_mode;
1544 uid = inode->i_uid;
1545 gid = inode->i_gid;
5955102c 1546 inode_unlock(inode);
8b01fc86
JH
1547
1548 /* We ignore suid/sgid if there are no mappings for them in the ns */
1549 if (!kuid_has_mapping(bprm->cred->user_ns, uid) ||
1550 !kgid_has_mapping(bprm->cred->user_ns, gid))
1551 return;
1552
1553 if (mode & S_ISUID) {
1554 bprm->per_clear |= PER_CLEAR_ON_SETID;
1555 bprm->cred->euid = uid;
1556 }
1557
1558 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
1559 bprm->per_clear |= PER_CLEAR_ON_SETID;
1560 bprm->cred->egid = gid;
1561 }
1562}
1563
9e00cdb0
ON
1564/*
1565 * Fill the binprm structure from the inode.
1da177e4 1566 * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
a6f76f23
DH
1567 *
1568 * This may be called multiple times for binary chains (scripts for example).
1da177e4
LT
1569 */
1570int prepare_binprm(struct linux_binprm *bprm)
1571{
1da177e4 1572 int retval;
bdd1d2d3 1573 loff_t pos = 0;
1da177e4 1574
8b01fc86 1575 bprm_fill_uid(bprm);
1da177e4
LT
1576
1577 /* fill in binprm security blob */
a6f76f23 1578 retval = security_bprm_set_creds(bprm);
1da177e4
LT
1579 if (retval)
1580 return retval;
ddb4a144 1581 bprm->called_set_creds = 1;
1da177e4 1582
a6f76f23 1583 memset(bprm->buf, 0, BINPRM_BUF_SIZE);
bdd1d2d3 1584 return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);
1da177e4
LT
1585}
1586
1587EXPORT_SYMBOL(prepare_binprm);
1588
4fc75ff4
NP
1589/*
1590 * Arguments are '\0' separated strings found at the location bprm->p
1591 * points to; chop off the first by relocating brpm->p to right after
1592 * the first '\0' encountered.
1593 */
b6a2fea3 1594int remove_arg_zero(struct linux_binprm *bprm)
1da177e4 1595{
b6a2fea3
OW
1596 int ret = 0;
1597 unsigned long offset;
1598 char *kaddr;
1599 struct page *page;
4fc75ff4 1600
b6a2fea3
OW
1601 if (!bprm->argc)
1602 return 0;
1da177e4 1603
b6a2fea3
OW
1604 do {
1605 offset = bprm->p & ~PAGE_MASK;
1606 page = get_arg_page(bprm, bprm->p, 0);
1607 if (!page) {
1608 ret = -EFAULT;
1609 goto out;
1610 }
e8e3c3d6 1611 kaddr = kmap_atomic(page);
4fc75ff4 1612
b6a2fea3
OW
1613 for (; offset < PAGE_SIZE && kaddr[offset];
1614 offset++, bprm->p++)
1615 ;
4fc75ff4 1616
e8e3c3d6 1617 kunmap_atomic(kaddr);
b6a2fea3 1618 put_arg_page(page);
b6a2fea3 1619 } while (offset == PAGE_SIZE);
4fc75ff4 1620
b6a2fea3
OW
1621 bprm->p++;
1622 bprm->argc--;
1623 ret = 0;
4fc75ff4 1624
b6a2fea3
OW
1625out:
1626 return ret;
1da177e4 1627}
1da177e4
LT
1628EXPORT_SYMBOL(remove_arg_zero);
1629
cb7b6b1c 1630#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
1da177e4
LT
1631/*
1632 * cycle the list of binary formats handler, until one recognizes the image
1633 */
3c456bfc 1634int search_binary_handler(struct linux_binprm *bprm)
1da177e4 1635{
cb7b6b1c 1636 bool need_retry = IS_ENABLED(CONFIG_MODULES);
1da177e4 1637 struct linux_binfmt *fmt;
cb7b6b1c 1638 int retval;
1da177e4 1639
d7402698 1640 /* This allows 4 levels of binfmt rewrites before failing hard. */
131b2f9f 1641 if (bprm->recursion_depth > 5)
d7402698
KC
1642 return -ELOOP;
1643
1da177e4
LT
1644 retval = security_bprm_check(bprm);
1645 if (retval)
1646 return retval;
1647
1da177e4 1648 retval = -ENOENT;
cb7b6b1c
ON
1649 retry:
1650 read_lock(&binfmt_lock);
1651 list_for_each_entry(fmt, &formats, lh) {
1652 if (!try_module_get(fmt->module))
1653 continue;
1654 read_unlock(&binfmt_lock);
1655 bprm->recursion_depth++;
1656 retval = fmt->load_binary(bprm);
19d860a1
AV
1657 read_lock(&binfmt_lock);
1658 put_binfmt(fmt);
cb7b6b1c 1659 bprm->recursion_depth--;
19d860a1
AV
1660 if (retval < 0 && !bprm->mm) {
1661 /* we got to flush_old_exec() and failed after it */
1662 read_unlock(&binfmt_lock);
1663 force_sigsegv(SIGSEGV, current);
1664 return retval;
1665 }
1666 if (retval != -ENOEXEC || !bprm->file) {
1667 read_unlock(&binfmt_lock);
cb7b6b1c 1668 return retval;
1da177e4 1669 }
1da177e4 1670 }
cb7b6b1c
ON
1671 read_unlock(&binfmt_lock);
1672
19d860a1 1673 if (need_retry) {
cb7b6b1c
ON
1674 if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
1675 printable(bprm->buf[2]) && printable(bprm->buf[3]))
1676 return retval;
4e0621a0
ON
1677 if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
1678 return retval;
cb7b6b1c
ON
1679 need_retry = false;
1680 goto retry;
1681 }
1682
1da177e4
LT
1683 return retval;
1684}
1da177e4
LT
1685EXPORT_SYMBOL(search_binary_handler);
1686
5d1baf3b
ON
1687static int exec_binprm(struct linux_binprm *bprm)
1688{
1689 pid_t old_pid, old_vpid;
1690 int ret;
1691
1692 /* Need to fetch pid before load_binary changes it */
1693 old_pid = current->pid;
1694 rcu_read_lock();
1695 old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
1696 rcu_read_unlock();
1697
1698 ret = search_binary_handler(bprm);
1699 if (ret >= 0) {
3eaded86 1700 audit_bprm(bprm);
5d1baf3b
ON
1701 trace_sched_process_exec(current, old_pid, bprm);
1702 ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
9beb266f 1703 proc_exec_connector(current);
5d1baf3b
ON
1704 }
1705
1706 return ret;
1707}
1708
1da177e4
LT
1709/*
1710 * sys_execve() executes a new program.
1711 */
449325b5
AS
1712static int __do_execve_file(int fd, struct filename *filename,
1713 struct user_arg_ptr argv,
1714 struct user_arg_ptr envp,
1715 int flags, struct file *file)
1da177e4 1716{
51f39a1f 1717 char *pathbuf = NULL;
1da177e4 1718 struct linux_binprm *bprm;
3b125388 1719 struct files_struct *displaced;
1da177e4 1720 int retval;
72fa5997 1721
c4ad8f98
LT
1722 if (IS_ERR(filename))
1723 return PTR_ERR(filename);
1724
72fa5997
VK
1725 /*
1726 * We move the actual failure in case of RLIMIT_NPROC excess from
1727 * set*uid() to execve() because too many poorly written programs
1728 * don't check setuid() return code. Here we additionally recheck
1729 * whether NPROC limit is still exceeded.
1730 */
1731 if ((current->flags & PF_NPROC_EXCEEDED) &&
bd9d43f4 1732 atomic_read(&current_user()->processes) > rlimit(RLIMIT_NPROC)) {
72fa5997
VK
1733 retval = -EAGAIN;
1734 goto out_ret;
1735 }
1736
1737 /* We're below the limit (still or again), so we don't want to make
1738 * further execve() calls fail. */
1739 current->flags &= ~PF_NPROC_EXCEEDED;
1da177e4 1740
3b125388 1741 retval = unshare_files(&displaced);
fd8328be
AV
1742 if (retval)
1743 goto out_ret;
1744
1da177e4 1745 retval = -ENOMEM;
11b0b5ab 1746 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
1da177e4 1747 if (!bprm)
fd8328be 1748 goto out_files;
1da177e4 1749
a2a8474c
ON
1750 retval = prepare_bprm_creds(bprm);
1751 if (retval)
a6f76f23 1752 goto out_free;
498052bb 1753
9e00cdb0 1754 check_unsafe_exec(bprm);
a2a8474c 1755 current->in_execve = 1;
a6f76f23 1756
449325b5
AS
1757 if (!file)
1758 file = do_open_execat(fd, filename, flags);
1da177e4
LT
1759 retval = PTR_ERR(file);
1760 if (IS_ERR(file))
498052bb 1761 goto out_unmark;
1da177e4
LT
1762
1763 sched_exec();
1764
1da177e4 1765 bprm->file = file;
449325b5
AS
1766 if (!filename) {
1767 bprm->filename = "none";
1768 } else if (fd == AT_FDCWD || filename->name[0] == '/') {
51f39a1f
DD
1769 bprm->filename = filename->name;
1770 } else {
1771 if (filename->name[0] == '\0')
0ee931c4 1772 pathbuf = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd);
51f39a1f 1773 else
0ee931c4 1774 pathbuf = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s",
51f39a1f
DD
1775 fd, filename->name);
1776 if (!pathbuf) {
1777 retval = -ENOMEM;
1778 goto out_unmark;
1779 }
1780 /*
1781 * Record that a name derived from an O_CLOEXEC fd will be
1782 * inaccessible after exec. Relies on having exclusive access to
1783 * current->files (due to unshare_files above).
1784 */
1785 if (close_on_exec(fd, rcu_dereference_raw(current->files->fdt)))
1786 bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
1787 bprm->filename = pathbuf;
1788 }
1789 bprm->interp = bprm->filename;
1da177e4 1790
b6a2fea3
OW
1791 retval = bprm_mm_init(bprm);
1792 if (retval)
63e46b95 1793 goto out_unmark;
1da177e4 1794
655c16a8
ON
1795 retval = prepare_arg_pages(bprm, argv, envp);
1796 if (retval < 0)
1da177e4
LT
1797 goto out;
1798
1799 retval = prepare_binprm(bprm);
1800 if (retval < 0)
1801 goto out;
1802
1803 retval = copy_strings_kernel(1, &bprm->filename, bprm);
1804 if (retval < 0)
1805 goto out;
1806
1807 bprm->exec = bprm->p;
1808 retval = copy_strings(bprm->envc, envp, bprm);
1809 if (retval < 0)
1810 goto out;
1811
1812 retval = copy_strings(bprm->argc, argv, bprm);
1813 if (retval < 0)
1814 goto out;
1815
f84df2a6
EB
1816 would_dump(bprm, bprm->file);
1817
5d1baf3b 1818 retval = exec_binprm(bprm);
a6f76f23
DH
1819 if (retval < 0)
1820 goto out;
1da177e4 1821
a6f76f23 1822 /* execve succeeded */
498052bb 1823 current->fs->in_exec = 0;
f9ce1f1c 1824 current->in_execve = 0;
a961e409 1825 membarrier_execve(current);
d7822b1e 1826 rseq_execve(current);
a6f76f23 1827 acct_update_integrals(current);
82727018 1828 task_numa_free(current);
a6f76f23 1829 free_bprm(bprm);
51f39a1f 1830 kfree(pathbuf);
449325b5
AS
1831 if (filename)
1832 putname(filename);
a6f76f23
DH
1833 if (displaced)
1834 put_files_struct(displaced);
1835 return retval;
1da177e4 1836
a6f76f23 1837out:
3c77f845
ON
1838 if (bprm->mm) {
1839 acct_arg_size(bprm, 0);
1840 mmput(bprm->mm);
1841 }
1da177e4 1842
498052bb 1843out_unmark:
9e00cdb0 1844 current->fs->in_exec = 0;
f9ce1f1c 1845 current->in_execve = 0;
a6f76f23
DH
1846
1847out_free:
08a6fac1 1848 free_bprm(bprm);
51f39a1f 1849 kfree(pathbuf);
1da177e4 1850
fd8328be 1851out_files:
3b125388
AV
1852 if (displaced)
1853 reset_files_struct(displaced);
1da177e4 1854out_ret:
449325b5
AS
1855 if (filename)
1856 putname(filename);
1da177e4
LT
1857 return retval;
1858}
1859
449325b5
AS
1860static int do_execveat_common(int fd, struct filename *filename,
1861 struct user_arg_ptr argv,
1862 struct user_arg_ptr envp,
1863 int flags)
1864{
1865 return __do_execve_file(fd, filename, argv, envp, flags, NULL);
1866}
1867
1868int do_execve_file(struct file *file, void *__argv, void *__envp)
1869{
1870 struct user_arg_ptr argv = { .ptr.native = __argv };
1871 struct user_arg_ptr envp = { .ptr.native = __envp };
1872
1873 return __do_execve_file(AT_FDCWD, NULL, argv, envp, 0, file);
1874}
1875
c4ad8f98 1876int do_execve(struct filename *filename,
ba2d0162 1877 const char __user *const __user *__argv,
da3d4c5f 1878 const char __user *const __user *__envp)
ba2d0162 1879{
0e028465
ON
1880 struct user_arg_ptr argv = { .ptr.native = __argv };
1881 struct user_arg_ptr envp = { .ptr.native = __envp };
51f39a1f
DD
1882 return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
1883}
1884
1885int do_execveat(int fd, struct filename *filename,
1886 const char __user *const __user *__argv,
1887 const char __user *const __user *__envp,
1888 int flags)
1889{
1890 struct user_arg_ptr argv = { .ptr.native = __argv };
1891 struct user_arg_ptr envp = { .ptr.native = __envp };
1892
1893 return do_execveat_common(fd, filename, argv, envp, flags);
0e028465
ON
1894}
1895
1896#ifdef CONFIG_COMPAT
c4ad8f98 1897static int compat_do_execve(struct filename *filename,
38b983b3 1898 const compat_uptr_t __user *__argv,
d03d26e5 1899 const compat_uptr_t __user *__envp)
0e028465
ON
1900{
1901 struct user_arg_ptr argv = {
1902 .is_compat = true,
1903 .ptr.compat = __argv,
1904 };
1905 struct user_arg_ptr envp = {
1906 .is_compat = true,
1907 .ptr.compat = __envp,
1908 };
51f39a1f
DD
1909 return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
1910}
1911
1912static int compat_do_execveat(int fd, struct filename *filename,
1913 const compat_uptr_t __user *__argv,
1914 const compat_uptr_t __user *__envp,
1915 int flags)
1916{
1917 struct user_arg_ptr argv = {
1918 .is_compat = true,
1919 .ptr.compat = __argv,
1920 };
1921 struct user_arg_ptr envp = {
1922 .is_compat = true,
1923 .ptr.compat = __envp,
1924 };
1925 return do_execveat_common(fd, filename, argv, envp, flags);
ba2d0162 1926}
0e028465 1927#endif
ba2d0162 1928
964ee7df 1929void set_binfmt(struct linux_binfmt *new)
1da177e4 1930{
801460d0
HS
1931 struct mm_struct *mm = current->mm;
1932
1933 if (mm->binfmt)
1934 module_put(mm->binfmt->module);
1da177e4 1935
801460d0 1936 mm->binfmt = new;
964ee7df
ON
1937 if (new)
1938 __module_get(new->module);
1da177e4 1939}
1da177e4
LT
1940EXPORT_SYMBOL(set_binfmt);
1941
6c5d5238 1942/*
7288e118 1943 * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
6c5d5238
KH
1944 */
1945void set_dumpable(struct mm_struct *mm, int value)
1946{
abacd2fe
ON
1947 unsigned long old, new;
1948
7288e118
ON
1949 if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
1950 return;
1951
abacd2fe 1952 do {
6aa7de05 1953 old = READ_ONCE(mm->flags);
7288e118 1954 new = (old & ~MMF_DUMPABLE_MASK) | value;
abacd2fe 1955 } while (cmpxchg(&mm->flags, old, new) != old);
6c5d5238 1956}
6c5d5238 1957
38b983b3
AV
1958SYSCALL_DEFINE3(execve,
1959 const char __user *, filename,
1960 const char __user *const __user *, argv,
1961 const char __user *const __user *, envp)
1962{
c4ad8f98 1963 return do_execve(getname(filename), argv, envp);
38b983b3 1964}
51f39a1f
DD
1965
1966SYSCALL_DEFINE5(execveat,
1967 int, fd, const char __user *, filename,
1968 const char __user *const __user *, argv,
1969 const char __user *const __user *, envp,
1970 int, flags)
1971{
1972 int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
1973
1974 return do_execveat(fd,
1975 getname_flags(filename, lookup_flags, NULL),
1976 argv, envp, flags);
1977}
1978
38b983b3 1979#ifdef CONFIG_COMPAT
625b1d7e
HC
1980COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
1981 const compat_uptr_t __user *, argv,
1982 const compat_uptr_t __user *, envp)
38b983b3 1983{
c4ad8f98 1984 return compat_do_execve(getname(filename), argv, envp);
38b983b3 1985}
51f39a1f
DD
1986
1987COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
1988 const char __user *, filename,
1989 const compat_uptr_t __user *, argv,
1990 const compat_uptr_t __user *, envp,
1991 int, flags)
1992{
1993 int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
1994
1995 return compat_do_execveat(fd,
1996 getname_flags(filename, lookup_flags, NULL),
1997 argv, envp, flags);
1998}
38b983b3 1999#endif