Commit | Line | Data |
---|---|---|
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 | |
22 | * formats. | |
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> |
1da177e4 LT |
29 | #include <linux/stat.h> |
30 | #include <linux/fcntl.h> | |
ba92a43d | 31 | #include <linux/swap.h> |
74aadce9 | 32 | #include <linux/string.h> |
1da177e4 | 33 | #include <linux/init.h> |
ca5b172b | 34 | #include <linux/pagemap.h> |
cdd6c482 | 35 | #include <linux/perf_event.h> |
1da177e4 LT |
36 | #include <linux/highmem.h> |
37 | #include <linux/spinlock.h> | |
38 | #include <linux/key.h> | |
39 | #include <linux/personality.h> | |
40 | #include <linux/binfmts.h> | |
1da177e4 | 41 | #include <linux/utsname.h> |
84d73786 | 42 | #include <linux/pid_namespace.h> |
1da177e4 LT |
43 | #include <linux/module.h> |
44 | #include <linux/namei.h> | |
1da177e4 LT |
45 | #include <linux/mount.h> |
46 | #include <linux/security.h> | |
47 | #include <linux/syscalls.h> | |
8f0ab514 | 48 | #include <linux/tsacct_kern.h> |
9f46080c | 49 | #include <linux/cn_proc.h> |
473ae30b | 50 | #include <linux/audit.h> |
6341c393 | 51 | #include <linux/tracehook.h> |
5f4123be | 52 | #include <linux/kmod.h> |
6110e3ab | 53 | #include <linux/fsnotify.h> |
5ad4e53b | 54 | #include <linux/fs_struct.h> |
61be228a | 55 | #include <linux/pipe_fs_i.h> |
3d5992d2 | 56 | #include <linux/oom.h> |
0e028465 | 57 | #include <linux/compat.h> |
1da177e4 LT |
58 | |
59 | #include <asm/uaccess.h> | |
60 | #include <asm/mmu_context.h> | |
b6a2fea3 | 61 | #include <asm/tlb.h> |
96f951ed | 62 | #include <asm/exec.h> |
43d2b113 KH |
63 | |
64 | #include <trace/events/task.h> | |
a6f76f23 | 65 | #include "internal.h" |
179899fd | 66 | #include "coredump.h" |
1da177e4 | 67 | |
4ff16c25 DS |
68 | #include <trace/events/sched.h> |
69 | ||
d6e71144 AC |
70 | int suid_dumpable = 0; |
71 | ||
e4dc1b14 | 72 | static LIST_HEAD(formats); |
1da177e4 LT |
73 | static DEFINE_RWLOCK(binfmt_lock); |
74 | ||
8fc3dc5a | 75 | void __register_binfmt(struct linux_binfmt * fmt, int insert) |
1da177e4 | 76 | { |
8fc3dc5a | 77 | BUG_ON(!fmt); |
1da177e4 | 78 | write_lock(&binfmt_lock); |
74641f58 IK |
79 | insert ? list_add(&fmt->lh, &formats) : |
80 | list_add_tail(&fmt->lh, &formats); | |
1da177e4 | 81 | write_unlock(&binfmt_lock); |
1da177e4 LT |
82 | } |
83 | ||
74641f58 | 84 | EXPORT_SYMBOL(__register_binfmt); |
1da177e4 | 85 | |
f6b450d4 | 86 | void unregister_binfmt(struct linux_binfmt * fmt) |
1da177e4 | 87 | { |
1da177e4 | 88 | write_lock(&binfmt_lock); |
e4dc1b14 | 89 | list_del(&fmt->lh); |
1da177e4 | 90 | write_unlock(&binfmt_lock); |
1da177e4 LT |
91 | } |
92 | ||
93 | EXPORT_SYMBOL(unregister_binfmt); | |
94 | ||
95 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
96 | { | |
97 | module_put(fmt->module); | |
98 | } | |
99 | ||
100 | /* | |
101 | * Note that a shared library must be both readable and executable due to | |
102 | * security reasons. | |
103 | * | |
104 | * Also note that we take the address to load from from the file itself. | |
105 | */ | |
1e7bfb21 | 106 | SYSCALL_DEFINE1(uselib, const char __user *, library) |
1da177e4 | 107 | { |
964bd183 | 108 | struct file *file; |
964bd183 AV |
109 | char *tmp = getname(library); |
110 | int error = PTR_ERR(tmp); | |
47c805dc AV |
111 | static const struct open_flags uselib_flags = { |
112 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
113 | .acc_mode = MAY_READ | MAY_EXEC | MAY_OPEN, | |
114 | .intent = LOOKUP_OPEN | |
115 | }; | |
964bd183 | 116 | |
6e8341a1 AV |
117 | if (IS_ERR(tmp)) |
118 | goto out; | |
119 | ||
47c805dc | 120 | file = do_filp_open(AT_FDCWD, tmp, &uselib_flags, LOOKUP_FOLLOW); |
6e8341a1 AV |
121 | putname(tmp); |
122 | error = PTR_ERR(file); | |
123 | if (IS_ERR(file)) | |
1da177e4 LT |
124 | goto out; |
125 | ||
126 | error = -EINVAL; | |
6e8341a1 | 127 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
1da177e4 LT |
128 | goto exit; |
129 | ||
30524472 | 130 | error = -EACCES; |
6e8341a1 | 131 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
1da177e4 LT |
132 | goto exit; |
133 | ||
2a12a9d7 | 134 | fsnotify_open(file); |
6110e3ab | 135 | |
1da177e4 LT |
136 | error = -ENOEXEC; |
137 | if(file->f_op) { | |
138 | struct linux_binfmt * fmt; | |
139 | ||
140 | read_lock(&binfmt_lock); | |
e4dc1b14 | 141 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
142 | if (!fmt->load_shlib) |
143 | continue; | |
144 | if (!try_module_get(fmt->module)) | |
145 | continue; | |
146 | read_unlock(&binfmt_lock); | |
147 | error = fmt->load_shlib(file); | |
148 | read_lock(&binfmt_lock); | |
149 | put_binfmt(fmt); | |
150 | if (error != -ENOEXEC) | |
151 | break; | |
152 | } | |
153 | read_unlock(&binfmt_lock); | |
154 | } | |
6e8341a1 | 155 | exit: |
1da177e4 LT |
156 | fput(file); |
157 | out: | |
158 | return error; | |
1da177e4 LT |
159 | } |
160 | ||
b6a2fea3 | 161 | #ifdef CONFIG_MMU |
ae6b585e ON |
162 | /* |
163 | * The nascent bprm->mm is not visible until exec_mmap() but it can | |
164 | * use a lot of memory, account these pages in current->mm temporary | |
165 | * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we | |
166 | * change the counter back via acct_arg_size(0). | |
167 | */ | |
0e028465 | 168 | static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
169 | { |
170 | struct mm_struct *mm = current->mm; | |
171 | long diff = (long)(pages - bprm->vma_pages); | |
172 | ||
173 | if (!mm || !diff) | |
174 | return; | |
175 | ||
176 | bprm->vma_pages = pages; | |
3c77f845 | 177 | add_mm_counter(mm, MM_ANONPAGES, diff); |
3c77f845 ON |
178 | } |
179 | ||
0e028465 | 180 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
181 | int write) |
182 | { | |
183 | struct page *page; | |
184 | int ret; | |
185 | ||
186 | #ifdef CONFIG_STACK_GROWSUP | |
187 | if (write) { | |
d05f3169 | 188 | ret = expand_downwards(bprm->vma, pos); |
b6a2fea3 OW |
189 | if (ret < 0) |
190 | return NULL; | |
191 | } | |
192 | #endif | |
193 | ret = get_user_pages(current, bprm->mm, pos, | |
194 | 1, write, 1, &page, NULL); | |
195 | if (ret <= 0) | |
196 | return NULL; | |
197 | ||
198 | if (write) { | |
b6a2fea3 | 199 | unsigned long size = bprm->vma->vm_end - bprm->vma->vm_start; |
a64e715f LT |
200 | struct rlimit *rlim; |
201 | ||
3c77f845 ON |
202 | acct_arg_size(bprm, size / PAGE_SIZE); |
203 | ||
a64e715f LT |
204 | /* |
205 | * We've historically supported up to 32 pages (ARG_MAX) | |
206 | * of argument strings even with small stacks | |
207 | */ | |
208 | if (size <= ARG_MAX) | |
209 | return page; | |
b6a2fea3 OW |
210 | |
211 | /* | |
212 | * Limit to 1/4-th the stack size for the argv+env strings. | |
213 | * This ensures that: | |
214 | * - the remaining binfmt code will not run out of stack space, | |
215 | * - the program will have a reasonable amount of stack left | |
216 | * to work from. | |
217 | */ | |
a64e715f | 218 | rlim = current->signal->rlim; |
d554ed89 | 219 | if (size > ACCESS_ONCE(rlim[RLIMIT_STACK].rlim_cur) / 4) { |
b6a2fea3 OW |
220 | put_page(page); |
221 | return NULL; | |
222 | } | |
223 | } | |
224 | ||
225 | return page; | |
226 | } | |
227 | ||
228 | static void put_arg_page(struct page *page) | |
229 | { | |
230 | put_page(page); | |
231 | } | |
232 | ||
233 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
234 | { | |
235 | } | |
236 | ||
237 | static void free_arg_pages(struct linux_binprm *bprm) | |
238 | { | |
239 | } | |
240 | ||
241 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
242 | struct page *page) | |
243 | { | |
244 | flush_cache_page(bprm->vma, pos, page_to_pfn(page)); | |
245 | } | |
246 | ||
247 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
248 | { | |
eaccbfa5 | 249 | int err; |
b6a2fea3 OW |
250 | struct vm_area_struct *vma = NULL; |
251 | struct mm_struct *mm = bprm->mm; | |
252 | ||
253 | bprm->vma = vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); | |
254 | if (!vma) | |
eaccbfa5 | 255 | return -ENOMEM; |
b6a2fea3 OW |
256 | |
257 | down_write(&mm->mmap_sem); | |
258 | vma->vm_mm = mm; | |
259 | ||
260 | /* | |
261 | * Place the stack at the largest stack address the architecture | |
262 | * supports. Later, we'll move this to an appropriate place. We don't | |
263 | * use STACK_TOP because that can depend on attributes which aren't | |
264 | * configured yet. | |
265 | */ | |
aacb3d17 | 266 | BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP); |
b6a2fea3 OW |
267 | vma->vm_end = STACK_TOP_MAX; |
268 | vma->vm_start = vma->vm_end - PAGE_SIZE; | |
a8bef8ff | 269 | vma->vm_flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP; |
3ed75eb8 | 270 | vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); |
5beb4930 | 271 | INIT_LIST_HEAD(&vma->anon_vma_chain); |
462e635e | 272 | |
b6a2fea3 | 273 | err = insert_vm_struct(mm, vma); |
eaccbfa5 | 274 | if (err) |
b6a2fea3 | 275 | goto err; |
b6a2fea3 OW |
276 | |
277 | mm->stack_vm = mm->total_vm = 1; | |
278 | up_write(&mm->mmap_sem); | |
b6a2fea3 | 279 | bprm->p = vma->vm_end - sizeof(void *); |
b6a2fea3 | 280 | return 0; |
b6a2fea3 | 281 | err: |
eaccbfa5 LFC |
282 | up_write(&mm->mmap_sem); |
283 | bprm->vma = NULL; | |
284 | kmem_cache_free(vm_area_cachep, vma); | |
b6a2fea3 OW |
285 | return err; |
286 | } | |
287 | ||
288 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
289 | { | |
290 | return len <= MAX_ARG_STRLEN; | |
291 | } | |
292 | ||
293 | #else | |
294 | ||
0e028465 | 295 | static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages) |
3c77f845 ON |
296 | { |
297 | } | |
298 | ||
0e028465 | 299 | static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, |
b6a2fea3 OW |
300 | int write) |
301 | { | |
302 | struct page *page; | |
303 | ||
304 | page = bprm->page[pos / PAGE_SIZE]; | |
305 | if (!page && write) { | |
306 | page = alloc_page(GFP_HIGHUSER|__GFP_ZERO); | |
307 | if (!page) | |
308 | return NULL; | |
309 | bprm->page[pos / PAGE_SIZE] = page; | |
310 | } | |
311 | ||
312 | return page; | |
313 | } | |
314 | ||
315 | static void put_arg_page(struct page *page) | |
316 | { | |
317 | } | |
318 | ||
319 | static void free_arg_page(struct linux_binprm *bprm, int i) | |
320 | { | |
321 | if (bprm->page[i]) { | |
322 | __free_page(bprm->page[i]); | |
323 | bprm->page[i] = NULL; | |
324 | } | |
325 | } | |
326 | ||
327 | static void free_arg_pages(struct linux_binprm *bprm) | |
328 | { | |
329 | int i; | |
330 | ||
331 | for (i = 0; i < MAX_ARG_PAGES; i++) | |
332 | free_arg_page(bprm, i); | |
333 | } | |
334 | ||
335 | static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos, | |
336 | struct page *page) | |
337 | { | |
338 | } | |
339 | ||
340 | static int __bprm_mm_init(struct linux_binprm *bprm) | |
341 | { | |
342 | bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *); | |
343 | return 0; | |
344 | } | |
345 | ||
346 | static bool valid_arg_len(struct linux_binprm *bprm, long len) | |
347 | { | |
348 | return len <= bprm->p; | |
349 | } | |
350 | ||
351 | #endif /* CONFIG_MMU */ | |
352 | ||
353 | /* | |
354 | * Create a new mm_struct and populate it with a temporary stack | |
355 | * vm_area_struct. We don't have enough context at this point to set the stack | |
356 | * flags, permissions, and offset, so we use temporary values. We'll update | |
357 | * them later in setup_arg_pages(). | |
358 | */ | |
359 | int bprm_mm_init(struct linux_binprm *bprm) | |
360 | { | |
361 | int err; | |
362 | struct mm_struct *mm = NULL; | |
363 | ||
364 | bprm->mm = mm = mm_alloc(); | |
365 | err = -ENOMEM; | |
366 | if (!mm) | |
367 | goto err; | |
368 | ||
369 | err = init_new_context(current, mm); | |
370 | if (err) | |
371 | goto err; | |
372 | ||
373 | err = __bprm_mm_init(bprm); | |
374 | if (err) | |
375 | goto err; | |
376 | ||
377 | return 0; | |
378 | ||
379 | err: | |
380 | if (mm) { | |
381 | bprm->mm = NULL; | |
382 | mmdrop(mm); | |
383 | } | |
384 | ||
385 | return err; | |
386 | } | |
387 | ||
ba2d0162 | 388 | struct 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 | |
395 | compat_uptr_t __user *compat; | |
396 | #endif | |
397 | } ptr; | |
ba2d0162 ON |
398 | }; |
399 | ||
400 | static 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 | 424 | static 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 | ||
362e6663 | 438 | if (i++ >= max) |
1da177e4 | 439 | return -E2BIG; |
9aea5a65 RM |
440 | |
441 | if (fatal_signal_pending(current)) | |
442 | return -ERESTARTNOHAND; | |
1da177e4 LT |
443 | cond_resched(); |
444 | } | |
445 | } | |
446 | return i; | |
447 | } | |
448 | ||
449 | /* | |
b6a2fea3 OW |
450 | * 'copy_strings()' copies argument/environment strings from the old |
451 | * processes's memory to the new process's stack. The call to get_user_pages() | |
452 | * ensures the destination page is created and not swapped out. | |
1da177e4 | 453 | */ |
ba2d0162 | 454 | static int copy_strings(int argc, struct user_arg_ptr argv, |
75c96f85 | 455 | struct linux_binprm *bprm) |
1da177e4 LT |
456 | { |
457 | struct page *kmapped_page = NULL; | |
458 | char *kaddr = NULL; | |
b6a2fea3 | 459 | unsigned long kpos = 0; |
1da177e4 LT |
460 | int ret; |
461 | ||
462 | while (argc-- > 0) { | |
d7627467 | 463 | const char __user *str; |
1da177e4 LT |
464 | int len; |
465 | unsigned long pos; | |
466 | ||
1d1dbf81 ON |
467 | ret = -EFAULT; |
468 | str = get_user_arg_ptr(argv, argc); | |
469 | if (IS_ERR(str)) | |
1da177e4 | 470 | goto out; |
1da177e4 | 471 | |
1d1dbf81 ON |
472 | len = strnlen_user(str, MAX_ARG_STRLEN); |
473 | if (!len) | |
474 | goto out; | |
475 | ||
476 | ret = -E2BIG; | |
477 | if (!valid_arg_len(bprm, len)) | |
1da177e4 | 478 | goto out; |
1da177e4 | 479 | |
b6a2fea3 | 480 | /* We're going to work our way backwords. */ |
1da177e4 | 481 | pos = bprm->p; |
b6a2fea3 OW |
482 | str += len; |
483 | bprm->p -= len; | |
1da177e4 LT |
484 | |
485 | while (len > 0) { | |
1da177e4 | 486 | int offset, bytes_to_copy; |
1da177e4 | 487 | |
9aea5a65 RM |
488 | if (fatal_signal_pending(current)) { |
489 | ret = -ERESTARTNOHAND; | |
490 | goto out; | |
491 | } | |
7993bc1f RM |
492 | cond_resched(); |
493 | ||
1da177e4 | 494 | offset = pos % PAGE_SIZE; |
b6a2fea3 OW |
495 | if (offset == 0) |
496 | offset = PAGE_SIZE; | |
497 | ||
498 | bytes_to_copy = offset; | |
499 | if (bytes_to_copy > len) | |
500 | bytes_to_copy = len; | |
501 | ||
502 | offset -= bytes_to_copy; | |
503 | pos -= bytes_to_copy; | |
504 | str -= bytes_to_copy; | |
505 | len -= bytes_to_copy; | |
506 | ||
507 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | |
508 | struct page *page; | |
509 | ||
510 | page = get_arg_page(bprm, pos, 1); | |
1da177e4 | 511 | if (!page) { |
b6a2fea3 | 512 | ret = -E2BIG; |
1da177e4 LT |
513 | goto out; |
514 | } | |
1da177e4 | 515 | |
b6a2fea3 OW |
516 | if (kmapped_page) { |
517 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 518 | kunmap(kmapped_page); |
b6a2fea3 OW |
519 | put_arg_page(kmapped_page); |
520 | } | |
1da177e4 LT |
521 | kmapped_page = page; |
522 | kaddr = kmap(kmapped_page); | |
b6a2fea3 OW |
523 | kpos = pos & PAGE_MASK; |
524 | flush_arg_page(bprm, kpos, kmapped_page); | |
1da177e4 | 525 | } |
b6a2fea3 | 526 | if (copy_from_user(kaddr+offset, str, bytes_to_copy)) { |
1da177e4 LT |
527 | ret = -EFAULT; |
528 | goto out; | |
529 | } | |
1da177e4 LT |
530 | } |
531 | } | |
532 | ret = 0; | |
533 | out: | |
b6a2fea3 OW |
534 | if (kmapped_page) { |
535 | flush_kernel_dcache_page(kmapped_page); | |
1da177e4 | 536 | kunmap(kmapped_page); |
b6a2fea3 OW |
537 | put_arg_page(kmapped_page); |
538 | } | |
1da177e4 LT |
539 | return ret; |
540 | } | |
541 | ||
542 | /* | |
543 | * Like copy_strings, but get argv and its values from kernel memory. | |
544 | */ | |
ba2d0162 | 545 | int copy_strings_kernel(int argc, const char *const *__argv, |
d7627467 | 546 | struct linux_binprm *bprm) |
1da177e4 LT |
547 | { |
548 | int r; | |
549 | mm_segment_t oldfs = get_fs(); | |
ba2d0162 | 550 | struct user_arg_ptr argv = { |
0e028465 | 551 | .ptr.native = (const char __user *const __user *)__argv, |
ba2d0162 ON |
552 | }; |
553 | ||
1da177e4 | 554 | set_fs(KERNEL_DS); |
ba2d0162 | 555 | r = copy_strings(argc, argv, bprm); |
1da177e4 | 556 | set_fs(oldfs); |
ba2d0162 | 557 | |
1da177e4 LT |
558 | return r; |
559 | } | |
1da177e4 LT |
560 | EXPORT_SYMBOL(copy_strings_kernel); |
561 | ||
562 | #ifdef CONFIG_MMU | |
b6a2fea3 | 563 | |
1da177e4 | 564 | /* |
b6a2fea3 OW |
565 | * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once |
566 | * the binfmt code determines where the new stack should reside, we shift it to | |
567 | * its final location. The process proceeds as follows: | |
1da177e4 | 568 | * |
b6a2fea3 OW |
569 | * 1) Use shift to calculate the new vma endpoints. |
570 | * 2) Extend vma to cover both the old and new ranges. This ensures the | |
571 | * arguments passed to subsequent functions are consistent. | |
572 | * 3) Move vma's page tables to the new range. | |
573 | * 4) Free up any cleared pgd range. | |
574 | * 5) Shrink the vma to cover only the new range. | |
1da177e4 | 575 | */ |
b6a2fea3 | 576 | static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) |
1da177e4 LT |
577 | { |
578 | struct mm_struct *mm = vma->vm_mm; | |
b6a2fea3 OW |
579 | unsigned long old_start = vma->vm_start; |
580 | unsigned long old_end = vma->vm_end; | |
581 | unsigned long length = old_end - old_start; | |
582 | unsigned long new_start = old_start - shift; | |
583 | unsigned long new_end = old_end - shift; | |
d16dfc55 | 584 | struct mmu_gather tlb; |
1da177e4 | 585 | |
b6a2fea3 | 586 | BUG_ON(new_start > new_end); |
1da177e4 | 587 | |
b6a2fea3 OW |
588 | /* |
589 | * ensure there are no vmas between where we want to go | |
590 | * and where we are | |
591 | */ | |
592 | if (vma != find_vma(mm, new_start)) | |
593 | return -EFAULT; | |
594 | ||
595 | /* | |
596 | * cover the whole range: [new_start, old_end) | |
597 | */ | |
5beb4930 RR |
598 | if (vma_adjust(vma, new_start, old_end, vma->vm_pgoff, NULL)) |
599 | return -ENOMEM; | |
b6a2fea3 OW |
600 | |
601 | /* | |
602 | * move the page tables downwards, on failure we rely on | |
603 | * process cleanup to remove whatever mess we made. | |
604 | */ | |
605 | if (length != move_page_tables(vma, old_start, | |
606 | vma, new_start, length)) | |
607 | return -ENOMEM; | |
608 | ||
609 | lru_add_drain(); | |
d16dfc55 | 610 | tlb_gather_mmu(&tlb, mm, 0); |
b6a2fea3 OW |
611 | if (new_end > old_start) { |
612 | /* | |
613 | * when the old and new regions overlap clear from new_end. | |
614 | */ | |
d16dfc55 | 615 | free_pgd_range(&tlb, new_end, old_end, new_end, |
b6a2fea3 OW |
616 | vma->vm_next ? vma->vm_next->vm_start : 0); |
617 | } else { | |
618 | /* | |
619 | * otherwise, clean from old_start; this is done to not touch | |
620 | * the address space in [new_end, old_start) some architectures | |
621 | * have constraints on va-space that make this illegal (IA64) - | |
622 | * for the others its just a little faster. | |
623 | */ | |
d16dfc55 | 624 | free_pgd_range(&tlb, old_start, old_end, new_end, |
b6a2fea3 | 625 | vma->vm_next ? vma->vm_next->vm_start : 0); |
1da177e4 | 626 | } |
d16dfc55 | 627 | tlb_finish_mmu(&tlb, new_end, old_end); |
b6a2fea3 OW |
628 | |
629 | /* | |
5beb4930 | 630 | * Shrink the vma to just the new range. Always succeeds. |
b6a2fea3 OW |
631 | */ |
632 | vma_adjust(vma, new_start, new_end, vma->vm_pgoff, NULL); | |
633 | ||
634 | return 0; | |
1da177e4 LT |
635 | } |
636 | ||
b6a2fea3 OW |
637 | /* |
638 | * Finalizes the stack vm_area_struct. The flags and permissions are updated, | |
639 | * the stack is optionally relocated, and some extra space is added. | |
640 | */ | |
1da177e4 LT |
641 | int setup_arg_pages(struct linux_binprm *bprm, |
642 | unsigned long stack_top, | |
643 | int executable_stack) | |
644 | { | |
b6a2fea3 OW |
645 | unsigned long ret; |
646 | unsigned long stack_shift; | |
1da177e4 | 647 | struct mm_struct *mm = current->mm; |
b6a2fea3 OW |
648 | struct vm_area_struct *vma = bprm->vma; |
649 | struct vm_area_struct *prev = NULL; | |
650 | unsigned long vm_flags; | |
651 | unsigned long stack_base; | |
803bf5ec MN |
652 | unsigned long stack_size; |
653 | unsigned long stack_expand; | |
654 | unsigned long rlim_stack; | |
1da177e4 LT |
655 | |
656 | #ifdef CONFIG_STACK_GROWSUP | |
1da177e4 | 657 | /* Limit stack size to 1GB */ |
d554ed89 | 658 | stack_base = rlimit_max(RLIMIT_STACK); |
1da177e4 LT |
659 | if (stack_base > (1 << 30)) |
660 | stack_base = 1 << 30; | |
1da177e4 | 661 | |
b6a2fea3 OW |
662 | /* Make sure we didn't let the argument array grow too large. */ |
663 | if (vma->vm_end - vma->vm_start > stack_base) | |
664 | return -ENOMEM; | |
1da177e4 | 665 | |
b6a2fea3 | 666 | stack_base = PAGE_ALIGN(stack_top - stack_base); |
1da177e4 | 667 | |
b6a2fea3 OW |
668 | stack_shift = vma->vm_start - stack_base; |
669 | mm->arg_start = bprm->p - stack_shift; | |
670 | bprm->p = vma->vm_end - stack_shift; | |
1da177e4 | 671 | #else |
b6a2fea3 OW |
672 | stack_top = arch_align_stack(stack_top); |
673 | stack_top = PAGE_ALIGN(stack_top); | |
1b528181 RM |
674 | |
675 | if (unlikely(stack_top < mmap_min_addr) || | |
676 | unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr)) | |
677 | return -ENOMEM; | |
678 | ||
b6a2fea3 OW |
679 | stack_shift = vma->vm_end - stack_top; |
680 | ||
681 | bprm->p -= stack_shift; | |
1da177e4 | 682 | mm->arg_start = bprm->p; |
1da177e4 LT |
683 | #endif |
684 | ||
1da177e4 | 685 | if (bprm->loader) |
b6a2fea3 OW |
686 | bprm->loader -= stack_shift; |
687 | bprm->exec -= stack_shift; | |
1da177e4 | 688 | |
1da177e4 | 689 | down_write(&mm->mmap_sem); |
96a8e13e | 690 | vm_flags = VM_STACK_FLAGS; |
b6a2fea3 OW |
691 | |
692 | /* | |
693 | * Adjust stack execute permissions; explicitly enable for | |
694 | * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone | |
695 | * (arch default) otherwise. | |
696 | */ | |
697 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
698 | vm_flags |= VM_EXEC; | |
699 | else if (executable_stack == EXSTACK_DISABLE_X) | |
700 | vm_flags &= ~VM_EXEC; | |
701 | vm_flags |= mm->def_flags; | |
a8bef8ff | 702 | vm_flags |= VM_STACK_INCOMPLETE_SETUP; |
b6a2fea3 OW |
703 | |
704 | ret = mprotect_fixup(vma, &prev, vma->vm_start, vma->vm_end, | |
705 | vm_flags); | |
706 | if (ret) | |
707 | goto out_unlock; | |
708 | BUG_ON(prev != vma); | |
709 | ||
710 | /* Move stack pages down in memory. */ | |
711 | if (stack_shift) { | |
712 | ret = shift_arg_pages(vma, stack_shift); | |
fc63cf23 AB |
713 | if (ret) |
714 | goto out_unlock; | |
1da177e4 LT |
715 | } |
716 | ||
a8bef8ff MG |
717 | /* mprotect_fixup is overkill to remove the temporary stack flags */ |
718 | vma->vm_flags &= ~VM_STACK_INCOMPLETE_SETUP; | |
719 | ||
5ef097dd | 720 | stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */ |
803bf5ec MN |
721 | stack_size = vma->vm_end - vma->vm_start; |
722 | /* | |
723 | * Align this down to a page boundary as expand_stack | |
724 | * will align it up. | |
725 | */ | |
726 | rlim_stack = rlimit(RLIMIT_STACK) & PAGE_MASK; | |
b6a2fea3 | 727 | #ifdef CONFIG_STACK_GROWSUP |
803bf5ec MN |
728 | if (stack_size + stack_expand > rlim_stack) |
729 | stack_base = vma->vm_start + rlim_stack; | |
730 | else | |
731 | stack_base = vma->vm_end + stack_expand; | |
b6a2fea3 | 732 | #else |
803bf5ec MN |
733 | if (stack_size + stack_expand > rlim_stack) |
734 | stack_base = vma->vm_end - rlim_stack; | |
735 | else | |
736 | stack_base = vma->vm_start - stack_expand; | |
b6a2fea3 | 737 | #endif |
3af9e859 | 738 | current->mm->start_stack = bprm->p; |
b6a2fea3 OW |
739 | ret = expand_stack(vma, stack_base); |
740 | if (ret) | |
741 | ret = -EFAULT; | |
742 | ||
743 | out_unlock: | |
1da177e4 | 744 | up_write(&mm->mmap_sem); |
fc63cf23 | 745 | return ret; |
1da177e4 | 746 | } |
1da177e4 LT |
747 | EXPORT_SYMBOL(setup_arg_pages); |
748 | ||
1da177e4 LT |
749 | #endif /* CONFIG_MMU */ |
750 | ||
751 | struct file *open_exec(const char *name) | |
752 | { | |
1da177e4 | 753 | struct file *file; |
e56b6a5d | 754 | int err; |
47c805dc AV |
755 | static const struct open_flags open_exec_flags = { |
756 | .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC, | |
757 | .acc_mode = MAY_EXEC | MAY_OPEN, | |
758 | .intent = LOOKUP_OPEN | |
759 | }; | |
1da177e4 | 760 | |
47c805dc | 761 | file = do_filp_open(AT_FDCWD, name, &open_exec_flags, LOOKUP_FOLLOW); |
6e8341a1 | 762 | if (IS_ERR(file)) |
e56b6a5d CH |
763 | goto out; |
764 | ||
765 | err = -EACCES; | |
6e8341a1 AV |
766 | if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) |
767 | goto exit; | |
e56b6a5d | 768 | |
6e8341a1 AV |
769 | if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
770 | goto exit; | |
e56b6a5d | 771 | |
2a12a9d7 | 772 | fsnotify_open(file); |
6110e3ab | 773 | |
e56b6a5d | 774 | err = deny_write_access(file); |
6e8341a1 AV |
775 | if (err) |
776 | goto exit; | |
1da177e4 | 777 | |
6e8341a1 | 778 | out: |
e56b6a5d CH |
779 | return file; |
780 | ||
6e8341a1 AV |
781 | exit: |
782 | fput(file); | |
e56b6a5d CH |
783 | return ERR_PTR(err); |
784 | } | |
1da177e4 LT |
785 | EXPORT_SYMBOL(open_exec); |
786 | ||
6777d773 MZ |
787 | int kernel_read(struct file *file, loff_t offset, |
788 | char *addr, unsigned long count) | |
1da177e4 LT |
789 | { |
790 | mm_segment_t old_fs; | |
791 | loff_t pos = offset; | |
792 | int result; | |
793 | ||
794 | old_fs = get_fs(); | |
795 | set_fs(get_ds()); | |
796 | /* The cast to a user pointer is valid due to the set_fs() */ | |
797 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
798 | set_fs(old_fs); | |
799 | return result; | |
800 | } | |
801 | ||
802 | EXPORT_SYMBOL(kernel_read); | |
803 | ||
804 | static int exec_mmap(struct mm_struct *mm) | |
805 | { | |
806 | struct task_struct *tsk; | |
807 | struct mm_struct * old_mm, *active_mm; | |
808 | ||
809 | /* Notify parent that we're no longer interested in the old VM */ | |
810 | tsk = current; | |
811 | old_mm = current->mm; | |
812 | mm_release(tsk, old_mm); | |
813 | ||
814 | if (old_mm) { | |
4fe7efdb | 815 | sync_mm_rss(old_mm); |
1da177e4 LT |
816 | /* |
817 | * Make sure that if there is a core dump in progress | |
818 | * for the old mm, we get out and die instead of going | |
819 | * through with the exec. We must hold mmap_sem around | |
999d9fc1 | 820 | * checking core_state and changing tsk->mm. |
1da177e4 LT |
821 | */ |
822 | down_read(&old_mm->mmap_sem); | |
999d9fc1 | 823 | if (unlikely(old_mm->core_state)) { |
1da177e4 LT |
824 | up_read(&old_mm->mmap_sem); |
825 | return -EINTR; | |
826 | } | |
827 | } | |
828 | task_lock(tsk); | |
829 | active_mm = tsk->active_mm; | |
830 | tsk->mm = mm; | |
831 | tsk->active_mm = mm; | |
832 | activate_mm(active_mm, mm); | |
833 | task_unlock(tsk); | |
834 | arch_pick_mmap_layout(mm); | |
835 | if (old_mm) { | |
836 | up_read(&old_mm->mmap_sem); | |
7dddb12c | 837 | BUG_ON(active_mm != old_mm); |
701085b2 | 838 | setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm); |
31a78f23 | 839 | mm_update_next_owner(old_mm); |
1da177e4 LT |
840 | mmput(old_mm); |
841 | return 0; | |
842 | } | |
843 | mmdrop(active_mm); | |
844 | return 0; | |
845 | } | |
846 | ||
847 | /* | |
848 | * This function makes sure the current process has its own signal table, | |
849 | * so that flush_signal_handlers can later reset the handlers without | |
850 | * disturbing other processes. (Other processes might share the signal | |
851 | * table via the CLONE_SIGHAND option to clone().) | |
852 | */ | |
858119e1 | 853 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
854 | { |
855 | struct signal_struct *sig = tsk->signal; | |
b2c903b8 | 856 | struct sighand_struct *oldsighand = tsk->sighand; |
1da177e4 | 857 | spinlock_t *lock = &oldsighand->siglock; |
1da177e4 | 858 | |
aafe6c2a | 859 | if (thread_group_empty(tsk)) |
1da177e4 LT |
860 | goto no_thread_group; |
861 | ||
862 | /* | |
863 | * Kill all other threads in the thread group. | |
1da177e4 | 864 | */ |
1da177e4 | 865 | spin_lock_irq(lock); |
ed5d2cac | 866 | if (signal_group_exit(sig)) { |
1da177e4 LT |
867 | /* |
868 | * Another group action in progress, just | |
869 | * return so that the signal is processed. | |
870 | */ | |
871 | spin_unlock_irq(lock); | |
1da177e4 LT |
872 | return -EAGAIN; |
873 | } | |
d344193a | 874 | |
ed5d2cac | 875 | sig->group_exit_task = tsk; |
d344193a ON |
876 | sig->notify_count = zap_other_threads(tsk); |
877 | if (!thread_group_leader(tsk)) | |
878 | sig->notify_count--; | |
1da177e4 | 879 | |
d344193a | 880 | while (sig->notify_count) { |
1da177e4 LT |
881 | __set_current_state(TASK_UNINTERRUPTIBLE); |
882 | spin_unlock_irq(lock); | |
883 | schedule(); | |
884 | spin_lock_irq(lock); | |
885 | } | |
1da177e4 LT |
886 | spin_unlock_irq(lock); |
887 | ||
888 | /* | |
889 | * At this point all other threads have exited, all we have to | |
890 | * do is to wait for the thread group leader to become inactive, | |
891 | * and to assume its PID: | |
892 | */ | |
aafe6c2a | 893 | if (!thread_group_leader(tsk)) { |
8187926b | 894 | struct task_struct *leader = tsk->group_leader; |
6db840fa | 895 | |
2800d8d1 | 896 | sig->notify_count = -1; /* for exit_notify() */ |
6db840fa ON |
897 | for (;;) { |
898 | write_lock_irq(&tasklist_lock); | |
899 | if (likely(leader->exit_state)) | |
900 | break; | |
901 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
902 | write_unlock_irq(&tasklist_lock); | |
903 | schedule(); | |
904 | } | |
1da177e4 | 905 | |
f5e90281 RM |
906 | /* |
907 | * The only record we have of the real-time age of a | |
908 | * process, regardless of execs it's done, is start_time. | |
909 | * All the past CPU time is accumulated in signal_struct | |
910 | * from sister threads now dead. But in this non-leader | |
911 | * exec, nothing survives from the original leader thread, | |
912 | * whose birth marks the true age of this process now. | |
913 | * When we take on its identity by switching to its PID, we | |
914 | * also take its birthdate (always earlier than our own). | |
915 | */ | |
aafe6c2a | 916 | tsk->start_time = leader->start_time; |
f5e90281 | 917 | |
bac0abd6 PE |
918 | BUG_ON(!same_thread_group(leader, tsk)); |
919 | BUG_ON(has_group_leader_pid(tsk)); | |
1da177e4 LT |
920 | /* |
921 | * An exec() starts a new thread group with the | |
922 | * TGID of the previous thread group. Rehash the | |
923 | * two threads with a switched PID, and release | |
924 | * the former thread group leader: | |
925 | */ | |
d73d6529 EB |
926 | |
927 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
928 | * The old leader becomes a thread of the this thread group. |
929 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
930 | * is called. Odd but simple and correct. |
931 | */ | |
aafe6c2a EB |
932 | detach_pid(tsk, PIDTYPE_PID); |
933 | tsk->pid = leader->pid; | |
3743ca05 | 934 | attach_pid(tsk, PIDTYPE_PID, task_pid(leader)); |
aafe6c2a EB |
935 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
936 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
9cd80bbb | 937 | |
aafe6c2a | 938 | list_replace_rcu(&leader->tasks, &tsk->tasks); |
9cd80bbb | 939 | list_replace_init(&leader->sibling, &tsk->sibling); |
1da177e4 | 940 | |
aafe6c2a EB |
941 | tsk->group_leader = tsk; |
942 | leader->group_leader = tsk; | |
de12a787 | 943 | |
aafe6c2a | 944 | tsk->exit_signal = SIGCHLD; |
087806b1 | 945 | leader->exit_signal = -1; |
962b564c ON |
946 | |
947 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
948 | leader->exit_state = EXIT_DEAD; | |
eac1b5e5 ON |
949 | |
950 | /* | |
951 | * We are going to release_task()->ptrace_unlink() silently, | |
952 | * the tracer can sleep in do_wait(). EXIT_DEAD guarantees | |
953 | * the tracer wont't block again waiting for this thread. | |
954 | */ | |
955 | if (unlikely(leader->ptrace)) | |
956 | __wake_up_parent(leader, leader->parent); | |
1da177e4 | 957 | write_unlock_irq(&tasklist_lock); |
8187926b ON |
958 | |
959 | release_task(leader); | |
ed5d2cac | 960 | } |
1da177e4 | 961 | |
6db840fa ON |
962 | sig->group_exit_task = NULL; |
963 | sig->notify_count = 0; | |
1da177e4 LT |
964 | |
965 | no_thread_group: | |
e6368253 ON |
966 | /* we have changed execution domain */ |
967 | tsk->exit_signal = SIGCHLD; | |
968 | ||
1da177e4 | 969 | exit_itimers(sig); |
cbaffba1 | 970 | flush_itimer_signals(); |
329f7dba | 971 | |
b2c903b8 ON |
972 | if (atomic_read(&oldsighand->count) != 1) { |
973 | struct sighand_struct *newsighand; | |
1da177e4 | 974 | /* |
b2c903b8 ON |
975 | * This ->sighand is shared with the CLONE_SIGHAND |
976 | * but not CLONE_THREAD task, switch to the new one. | |
1da177e4 | 977 | */ |
b2c903b8 ON |
978 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); |
979 | if (!newsighand) | |
980 | return -ENOMEM; | |
981 | ||
1da177e4 LT |
982 | atomic_set(&newsighand->count, 1); |
983 | memcpy(newsighand->action, oldsighand->action, | |
984 | sizeof(newsighand->action)); | |
985 | ||
986 | write_lock_irq(&tasklist_lock); | |
987 | spin_lock(&oldsighand->siglock); | |
aafe6c2a | 988 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
989 | spin_unlock(&oldsighand->siglock); |
990 | write_unlock_irq(&tasklist_lock); | |
991 | ||
fba2afaa | 992 | __cleanup_sighand(oldsighand); |
1da177e4 LT |
993 | } |
994 | ||
aafe6c2a | 995 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
996 | return 0; |
997 | } | |
0840a90d | 998 | |
59714d65 | 999 | char *get_task_comm(char *buf, struct task_struct *tsk) |
1da177e4 LT |
1000 | { |
1001 | /* buf must be at least sizeof(tsk->comm) in size */ | |
1002 | task_lock(tsk); | |
1003 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
1004 | task_unlock(tsk); | |
59714d65 | 1005 | return buf; |
1da177e4 | 1006 | } |
7d74f492 | 1007 | EXPORT_SYMBOL_GPL(get_task_comm); |
1da177e4 | 1008 | |
6a6d27de AV |
1009 | /* |
1010 | * These functions flushes out all traces of the currently running executable | |
1011 | * so that a new one can be started | |
1012 | */ | |
1013 | ||
1da177e4 LT |
1014 | void set_task_comm(struct task_struct *tsk, char *buf) |
1015 | { | |
1016 | task_lock(tsk); | |
4614a696 | 1017 | |
43d2b113 KH |
1018 | trace_task_rename(tsk, buf); |
1019 | ||
4614a696 | 1020 | /* |
1021 | * Threads may access current->comm without holding | |
1022 | * the task lock, so write the string carefully. | |
1023 | * Readers without a lock may see incomplete new | |
1024 | * names but are safe from non-terminating string reads. | |
1025 | */ | |
1026 | memset(tsk->comm, 0, TASK_COMM_LEN); | |
1027 | wmb(); | |
1da177e4 LT |
1028 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); |
1029 | task_unlock(tsk); | |
cdd6c482 | 1030 | perf_event_comm(tsk); |
1da177e4 LT |
1031 | } |
1032 | ||
96e02d15 HC |
1033 | static void filename_to_taskname(char *tcomm, const char *fn, unsigned int len) |
1034 | { | |
1035 | int i, ch; | |
1036 | ||
1037 | /* Copies the binary name from after last slash */ | |
1038 | for (i = 0; (ch = *(fn++)) != '\0';) { | |
1039 | if (ch == '/') | |
1040 | i = 0; /* overwrite what we wrote */ | |
1041 | else | |
1042 | if (i < len - 1) | |
1043 | tcomm[i++] = ch; | |
1044 | } | |
1045 | tcomm[i] = '\0'; | |
1046 | } | |
1047 | ||
1da177e4 LT |
1048 | int flush_old_exec(struct linux_binprm * bprm) |
1049 | { | |
221af7f8 | 1050 | int retval; |
1da177e4 LT |
1051 | |
1052 | /* | |
1053 | * Make sure we have a private signal table and that | |
1054 | * we are unassociated from the previous thread group. | |
1055 | */ | |
1056 | retval = de_thread(current); | |
1057 | if (retval) | |
1058 | goto out; | |
1059 | ||
925d1c40 MH |
1060 | set_mm_exe_file(bprm->mm, bprm->file); |
1061 | ||
96e02d15 | 1062 | filename_to_taskname(bprm->tcomm, bprm->filename, sizeof(bprm->tcomm)); |
1da177e4 LT |
1063 | /* |
1064 | * Release all of the old mmap stuff | |
1065 | */ | |
3c77f845 | 1066 | acct_arg_size(bprm, 0); |
1da177e4 LT |
1067 | retval = exec_mmap(bprm->mm); |
1068 | if (retval) | |
fd8328be | 1069 | goto out; |
1da177e4 LT |
1070 | |
1071 | bprm->mm = NULL; /* We're using it now */ | |
7ab02af4 | 1072 | |
dac853ae | 1073 | set_fs(USER_DS); |
19e5109f | 1074 | current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD); |
7ab02af4 LT |
1075 | flush_thread(); |
1076 | current->personality &= ~bprm->per_clear; | |
1077 | ||
221af7f8 LT |
1078 | return 0; |
1079 | ||
1080 | out: | |
1081 | return retval; | |
1082 | } | |
1083 | EXPORT_SYMBOL(flush_old_exec); | |
1084 | ||
1b5d783c AV |
1085 | void would_dump(struct linux_binprm *bprm, struct file *file) |
1086 | { | |
1087 | if (inode_permission(file->f_path.dentry->d_inode, MAY_READ) < 0) | |
1088 | bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; | |
1089 | } | |
1090 | EXPORT_SYMBOL(would_dump); | |
1091 | ||
221af7f8 LT |
1092 | void setup_new_exec(struct linux_binprm * bprm) |
1093 | { | |
221af7f8 | 1094 | arch_pick_mmap_layout(current->mm); |
1da177e4 LT |
1095 | |
1096 | /* This is the point of no return */ | |
1da177e4 LT |
1097 | current->sas_ss_sp = current->sas_ss_size = 0; |
1098 | ||
8e96e3b7 | 1099 | if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid())) |
0f4cfb2e | 1100 | set_dumpable(current->mm, SUID_DUMPABLE_ENABLED); |
d6e71144 | 1101 | else |
6c5d5238 | 1102 | set_dumpable(current->mm, suid_dumpable); |
d6e71144 | 1103 | |
96e02d15 | 1104 | set_task_comm(current, bprm->tcomm); |
1da177e4 | 1105 | |
0551fbd2 BH |
1106 | /* Set the new mm task size. We have to do that late because it may |
1107 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
1108 | * some architectures like powerpc | |
1109 | */ | |
1110 | current->mm->task_size = TASK_SIZE; | |
1111 | ||
a6f76f23 | 1112 | /* install the new credentials */ |
8e96e3b7 EB |
1113 | if (!uid_eq(bprm->cred->uid, current_euid()) || |
1114 | !gid_eq(bprm->cred->gid, current_egid())) { | |
d2d56c5f | 1115 | current->pdeath_signal = 0; |
1b5d783c AV |
1116 | } else { |
1117 | would_dump(bprm, bprm->file); | |
1118 | if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP) | |
1119 | set_dumpable(current->mm, suid_dumpable); | |
1da177e4 LT |
1120 | } |
1121 | ||
f65cb45c IM |
1122 | /* |
1123 | * Flush performance counters when crossing a | |
1124 | * security domain: | |
1125 | */ | |
1126 | if (!get_dumpable(current->mm)) | |
cdd6c482 | 1127 | perf_event_exit_task(current); |
f65cb45c | 1128 | |
1da177e4 LT |
1129 | /* An exec changes our domain. We are no longer part of the thread |
1130 | group */ | |
1131 | ||
1132 | current->self_exec_id++; | |
1133 | ||
1134 | flush_signal_handlers(current, 0); | |
6a6d27de | 1135 | do_close_on_exec(current->files); |
1da177e4 | 1136 | } |
221af7f8 | 1137 | EXPORT_SYMBOL(setup_new_exec); |
1da177e4 | 1138 | |
a2a8474c ON |
1139 | /* |
1140 | * Prepare credentials and lock ->cred_guard_mutex. | |
1141 | * install_exec_creds() commits the new creds and drops the lock. | |
1142 | * Or, if exec fails before, free_bprm() should release ->cred and | |
1143 | * and unlock. | |
1144 | */ | |
1145 | int prepare_bprm_creds(struct linux_binprm *bprm) | |
1146 | { | |
9b1bf12d | 1147 | if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex)) |
a2a8474c ON |
1148 | return -ERESTARTNOINTR; |
1149 | ||
1150 | bprm->cred = prepare_exec_creds(); | |
1151 | if (likely(bprm->cred)) | |
1152 | return 0; | |
1153 | ||
9b1bf12d | 1154 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1155 | return -ENOMEM; |
1156 | } | |
1157 | ||
1158 | void free_bprm(struct linux_binprm *bprm) | |
1159 | { | |
1160 | free_arg_pages(bprm); | |
1161 | if (bprm->cred) { | |
9b1bf12d | 1162 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a2a8474c ON |
1163 | abort_creds(bprm->cred); |
1164 | } | |
1165 | kfree(bprm); | |
1166 | } | |
1167 | ||
a6f76f23 DH |
1168 | /* |
1169 | * install the new credentials for this executable | |
1170 | */ | |
1171 | void install_exec_creds(struct linux_binprm *bprm) | |
1172 | { | |
1173 | security_bprm_committing_creds(bprm); | |
1174 | ||
1175 | commit_creds(bprm->cred); | |
1176 | bprm->cred = NULL; | |
a2a8474c ON |
1177 | /* |
1178 | * cred_guard_mutex must be held at least to this point to prevent | |
a6f76f23 | 1179 | * ptrace_attach() from altering our determination of the task's |
a2a8474c ON |
1180 | * credentials; any time after this it may be unlocked. |
1181 | */ | |
a6f76f23 | 1182 | security_bprm_committed_creds(bprm); |
9b1bf12d | 1183 | mutex_unlock(¤t->signal->cred_guard_mutex); |
a6f76f23 DH |
1184 | } |
1185 | EXPORT_SYMBOL(install_exec_creds); | |
1186 | ||
1187 | /* | |
1188 | * determine how safe it is to execute the proposed program | |
9b1bf12d | 1189 | * - the caller must hold ->cred_guard_mutex to protect against |
a6f76f23 DH |
1190 | * PTRACE_ATTACH |
1191 | */ | |
f47ec3f2 | 1192 | static int check_unsafe_exec(struct linux_binprm *bprm) |
a6f76f23 | 1193 | { |
0bf2f3ae | 1194 | struct task_struct *p = current, *t; |
f1191b50 | 1195 | unsigned n_fs; |
498052bb | 1196 | int res = 0; |
a6f76f23 | 1197 | |
4b9d33e6 TH |
1198 | if (p->ptrace) { |
1199 | if (p->ptrace & PT_PTRACE_CAP) | |
1200 | bprm->unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
1201 | else | |
1202 | bprm->unsafe |= LSM_UNSAFE_PTRACE; | |
1203 | } | |
a6f76f23 | 1204 | |
259e5e6c AL |
1205 | /* |
1206 | * This isn't strictly necessary, but it makes it harder for LSMs to | |
1207 | * mess up. | |
1208 | */ | |
1209 | if (current->no_new_privs) | |
1210 | bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; | |
1211 | ||
0bf2f3ae | 1212 | n_fs = 1; |
2a4419b5 | 1213 | spin_lock(&p->fs->lock); |
437f7fdb | 1214 | rcu_read_lock(); |
0bf2f3ae DH |
1215 | for (t = next_thread(p); t != p; t = next_thread(t)) { |
1216 | if (t->fs == p->fs) | |
1217 | n_fs++; | |
0bf2f3ae | 1218 | } |
437f7fdb | 1219 | rcu_read_unlock(); |
0bf2f3ae | 1220 | |
f1191b50 | 1221 | if (p->fs->users > n_fs) { |
a6f76f23 | 1222 | bprm->unsafe |= LSM_UNSAFE_SHARE; |
498052bb | 1223 | } else { |
8c652f96 ON |
1224 | res = -EAGAIN; |
1225 | if (!p->fs->in_exec) { | |
1226 | p->fs->in_exec = 1; | |
1227 | res = 1; | |
1228 | } | |
498052bb | 1229 | } |
2a4419b5 | 1230 | spin_unlock(&p->fs->lock); |
498052bb AV |
1231 | |
1232 | return res; | |
a6f76f23 DH |
1233 | } |
1234 | ||
1da177e4 LT |
1235 | /* |
1236 | * Fill the binprm structure from the inode. | |
1237 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
a6f76f23 DH |
1238 | * |
1239 | * This may be called multiple times for binary chains (scripts for example). | |
1da177e4 LT |
1240 | */ |
1241 | int prepare_binprm(struct linux_binprm *bprm) | |
1242 | { | |
a6f76f23 | 1243 | umode_t mode; |
0f7fc9e4 | 1244 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
1245 | int retval; |
1246 | ||
1247 | mode = inode->i_mode; | |
1da177e4 LT |
1248 | if (bprm->file->f_op == NULL) |
1249 | return -EACCES; | |
1250 | ||
a6f76f23 DH |
1251 | /* clear any previous set[ug]id data from a previous binary */ |
1252 | bprm->cred->euid = current_euid(); | |
1253 | bprm->cred->egid = current_egid(); | |
1da177e4 | 1254 | |
259e5e6c AL |
1255 | if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) && |
1256 | !current->no_new_privs) { | |
1da177e4 LT |
1257 | /* Set-uid? */ |
1258 | if (mode & S_ISUID) { | |
9e4a36ec EB |
1259 | if (!kuid_has_mapping(bprm->cred->user_ns, inode->i_uid)) |
1260 | return -EPERM; | |
a6f76f23 DH |
1261 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1262 | bprm->cred->euid = inode->i_uid; | |
9e4a36ec | 1263 | |
1da177e4 LT |
1264 | } |
1265 | ||
1266 | /* Set-gid? */ | |
1267 | /* | |
1268 | * If setgid is set but no group execute bit then this | |
1269 | * is a candidate for mandatory locking, not a setgid | |
1270 | * executable. | |
1271 | */ | |
1272 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
9e4a36ec EB |
1273 | if (!kgid_has_mapping(bprm->cred->user_ns, inode->i_gid)) |
1274 | return -EPERM; | |
a6f76f23 DH |
1275 | bprm->per_clear |= PER_CLEAR_ON_SETID; |
1276 | bprm->cred->egid = inode->i_gid; | |
1da177e4 LT |
1277 | } |
1278 | } | |
1279 | ||
1280 | /* fill in binprm security blob */ | |
a6f76f23 | 1281 | retval = security_bprm_set_creds(bprm); |
1da177e4 LT |
1282 | if (retval) |
1283 | return retval; | |
a6f76f23 | 1284 | bprm->cred_prepared = 1; |
1da177e4 | 1285 | |
a6f76f23 DH |
1286 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); |
1287 | return kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); | |
1da177e4 LT |
1288 | } |
1289 | ||
1290 | EXPORT_SYMBOL(prepare_binprm); | |
1291 | ||
4fc75ff4 NP |
1292 | /* |
1293 | * Arguments are '\0' separated strings found at the location bprm->p | |
1294 | * points to; chop off the first by relocating brpm->p to right after | |
1295 | * the first '\0' encountered. | |
1296 | */ | |
b6a2fea3 | 1297 | int remove_arg_zero(struct linux_binprm *bprm) |
1da177e4 | 1298 | { |
b6a2fea3 OW |
1299 | int ret = 0; |
1300 | unsigned long offset; | |
1301 | char *kaddr; | |
1302 | struct page *page; | |
4fc75ff4 | 1303 | |
b6a2fea3 OW |
1304 | if (!bprm->argc) |
1305 | return 0; | |
1da177e4 | 1306 | |
b6a2fea3 OW |
1307 | do { |
1308 | offset = bprm->p & ~PAGE_MASK; | |
1309 | page = get_arg_page(bprm, bprm->p, 0); | |
1310 | if (!page) { | |
1311 | ret = -EFAULT; | |
1312 | goto out; | |
1313 | } | |
e8e3c3d6 | 1314 | kaddr = kmap_atomic(page); |
4fc75ff4 | 1315 | |
b6a2fea3 OW |
1316 | for (; offset < PAGE_SIZE && kaddr[offset]; |
1317 | offset++, bprm->p++) | |
1318 | ; | |
4fc75ff4 | 1319 | |
e8e3c3d6 | 1320 | kunmap_atomic(kaddr); |
b6a2fea3 | 1321 | put_arg_page(page); |
4fc75ff4 | 1322 | |
b6a2fea3 OW |
1323 | if (offset == PAGE_SIZE) |
1324 | free_arg_page(bprm, (bprm->p >> PAGE_SHIFT) - 1); | |
1325 | } while (offset == PAGE_SIZE); | |
4fc75ff4 | 1326 | |
b6a2fea3 OW |
1327 | bprm->p++; |
1328 | bprm->argc--; | |
1329 | ret = 0; | |
4fc75ff4 | 1330 | |
b6a2fea3 OW |
1331 | out: |
1332 | return ret; | |
1da177e4 | 1333 | } |
1da177e4 LT |
1334 | EXPORT_SYMBOL(remove_arg_zero); |
1335 | ||
1336 | /* | |
1337 | * cycle the list of binary formats handler, until one recognizes the image | |
1338 | */ | |
1339 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1340 | { | |
85f33466 | 1341 | unsigned int depth = bprm->recursion_depth; |
1da177e4 LT |
1342 | int try,retval; |
1343 | struct linux_binfmt *fmt; | |
6308191f | 1344 | pid_t old_pid, old_vpid; |
1da177e4 | 1345 | |
1da177e4 LT |
1346 | retval = security_bprm_check(bprm); |
1347 | if (retval) | |
1348 | return retval; | |
1349 | ||
473ae30b AV |
1350 | retval = audit_bprm(bprm); |
1351 | if (retval) | |
1352 | return retval; | |
1353 | ||
bb188d7e | 1354 | /* Need to fetch pid before load_binary changes it */ |
6308191f | 1355 | old_pid = current->pid; |
bb188d7e | 1356 | rcu_read_lock(); |
6308191f | 1357 | old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent)); |
bb188d7e DV |
1358 | rcu_read_unlock(); |
1359 | ||
1da177e4 LT |
1360 | retval = -ENOENT; |
1361 | for (try=0; try<2; try++) { | |
1362 | read_lock(&binfmt_lock); | |
e4dc1b14 | 1363 | list_for_each_entry(fmt, &formats, lh) { |
1da177e4 LT |
1364 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; |
1365 | if (!fn) | |
1366 | continue; | |
1367 | if (!try_module_get(fmt->module)) | |
1368 | continue; | |
1369 | read_unlock(&binfmt_lock); | |
1370 | retval = fn(bprm, regs); | |
85f33466 RM |
1371 | /* |
1372 | * Restore the depth counter to its starting value | |
1373 | * in this call, so we don't have to rely on every | |
1374 | * load_binary function to restore it on return. | |
1375 | */ | |
1376 | bprm->recursion_depth = depth; | |
1da177e4 | 1377 | if (retval >= 0) { |
4ff16c25 DS |
1378 | if (depth == 0) { |
1379 | trace_sched_process_exec(current, old_pid, bprm); | |
6308191f | 1380 | ptrace_event(PTRACE_EVENT_EXEC, old_vpid); |
4ff16c25 | 1381 | } |
1da177e4 LT |
1382 | put_binfmt(fmt); |
1383 | allow_write_access(bprm->file); | |
1384 | if (bprm->file) | |
1385 | fput(bprm->file); | |
1386 | bprm->file = NULL; | |
1387 | current->did_exec = 1; | |
9f46080c | 1388 | proc_exec_connector(current); |
1da177e4 LT |
1389 | return retval; |
1390 | } | |
1391 | read_lock(&binfmt_lock); | |
1392 | put_binfmt(fmt); | |
1393 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1394 | break; | |
1395 | if (!bprm->file) { | |
1396 | read_unlock(&binfmt_lock); | |
1397 | return retval; | |
1398 | } | |
1399 | } | |
1400 | read_unlock(&binfmt_lock); | |
b4edf8bd | 1401 | #ifdef CONFIG_MODULES |
1da177e4 LT |
1402 | if (retval != -ENOEXEC || bprm->mm == NULL) { |
1403 | break; | |
5f4123be | 1404 | } else { |
1da177e4 LT |
1405 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) |
1406 | if (printable(bprm->buf[0]) && | |
1407 | printable(bprm->buf[1]) && | |
1408 | printable(bprm->buf[2]) && | |
1409 | printable(bprm->buf[3])) | |
1410 | break; /* -ENOEXEC */ | |
91219352 TH |
1411 | if (try) |
1412 | break; /* -ENOEXEC */ | |
1da177e4 | 1413 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); |
1da177e4 | 1414 | } |
b4edf8bd TH |
1415 | #else |
1416 | break; | |
1417 | #endif | |
1da177e4 LT |
1418 | } |
1419 | return retval; | |
1420 | } | |
1421 | ||
1422 | EXPORT_SYMBOL(search_binary_handler); | |
1423 | ||
1424 | /* | |
1425 | * sys_execve() executes a new program. | |
1426 | */ | |
ba2d0162 ON |
1427 | static int do_execve_common(const char *filename, |
1428 | struct user_arg_ptr argv, | |
1429 | struct user_arg_ptr envp, | |
1430 | struct pt_regs *regs) | |
1da177e4 LT |
1431 | { |
1432 | struct linux_binprm *bprm; | |
1433 | struct file *file; | |
3b125388 | 1434 | struct files_struct *displaced; |
8c652f96 | 1435 | bool clear_in_exec; |
1da177e4 | 1436 | int retval; |
72fa5997 VK |
1437 | const struct cred *cred = current_cred(); |
1438 | ||
1439 | /* | |
1440 | * We move the actual failure in case of RLIMIT_NPROC excess from | |
1441 | * set*uid() to execve() because too many poorly written programs | |
1442 | * don't check setuid() return code. Here we additionally recheck | |
1443 | * whether NPROC limit is still exceeded. | |
1444 | */ | |
1445 | if ((current->flags & PF_NPROC_EXCEEDED) && | |
1446 | atomic_read(&cred->user->processes) > rlimit(RLIMIT_NPROC)) { | |
1447 | retval = -EAGAIN; | |
1448 | goto out_ret; | |
1449 | } | |
1450 | ||
1451 | /* We're below the limit (still or again), so we don't want to make | |
1452 | * further execve() calls fail. */ | |
1453 | current->flags &= ~PF_NPROC_EXCEEDED; | |
1da177e4 | 1454 | |
3b125388 | 1455 | retval = unshare_files(&displaced); |
fd8328be AV |
1456 | if (retval) |
1457 | goto out_ret; | |
1458 | ||
1da177e4 | 1459 | retval = -ENOMEM; |
11b0b5ab | 1460 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 | 1461 | if (!bprm) |
fd8328be | 1462 | goto out_files; |
1da177e4 | 1463 | |
a2a8474c ON |
1464 | retval = prepare_bprm_creds(bprm); |
1465 | if (retval) | |
a6f76f23 | 1466 | goto out_free; |
498052bb AV |
1467 | |
1468 | retval = check_unsafe_exec(bprm); | |
8c652f96 | 1469 | if (retval < 0) |
a2a8474c | 1470 | goto out_free; |
8c652f96 | 1471 | clear_in_exec = retval; |
a2a8474c | 1472 | current->in_execve = 1; |
a6f76f23 | 1473 | |
1da177e4 LT |
1474 | file = open_exec(filename); |
1475 | retval = PTR_ERR(file); | |
1476 | if (IS_ERR(file)) | |
498052bb | 1477 | goto out_unmark; |
1da177e4 LT |
1478 | |
1479 | sched_exec(); | |
1480 | ||
1da177e4 LT |
1481 | bprm->file = file; |
1482 | bprm->filename = filename; | |
1483 | bprm->interp = filename; | |
1da177e4 | 1484 | |
b6a2fea3 OW |
1485 | retval = bprm_mm_init(bprm); |
1486 | if (retval) | |
1487 | goto out_file; | |
1da177e4 | 1488 | |
b6a2fea3 | 1489 | bprm->argc = count(argv, MAX_ARG_STRINGS); |
1da177e4 | 1490 | if ((retval = bprm->argc) < 0) |
a6f76f23 | 1491 | goto out; |
1da177e4 | 1492 | |
b6a2fea3 | 1493 | bprm->envc = count(envp, MAX_ARG_STRINGS); |
1da177e4 | 1494 | if ((retval = bprm->envc) < 0) |
1da177e4 LT |
1495 | goto out; |
1496 | ||
1497 | retval = prepare_binprm(bprm); | |
1498 | if (retval < 0) | |
1499 | goto out; | |
1500 | ||
1501 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1502 | if (retval < 0) | |
1503 | goto out; | |
1504 | ||
1505 | bprm->exec = bprm->p; | |
1506 | retval = copy_strings(bprm->envc, envp, bprm); | |
1507 | if (retval < 0) | |
1508 | goto out; | |
1509 | ||
1510 | retval = copy_strings(bprm->argc, argv, bprm); | |
1511 | if (retval < 0) | |
1512 | goto out; | |
1513 | ||
1514 | retval = search_binary_handler(bprm,regs); | |
a6f76f23 DH |
1515 | if (retval < 0) |
1516 | goto out; | |
1da177e4 | 1517 | |
a6f76f23 | 1518 | /* execve succeeded */ |
498052bb | 1519 | current->fs->in_exec = 0; |
f9ce1f1c | 1520 | current->in_execve = 0; |
a6f76f23 DH |
1521 | acct_update_integrals(current); |
1522 | free_bprm(bprm); | |
1523 | if (displaced) | |
1524 | put_files_struct(displaced); | |
1525 | return retval; | |
1da177e4 | 1526 | |
a6f76f23 | 1527 | out: |
3c77f845 ON |
1528 | if (bprm->mm) { |
1529 | acct_arg_size(bprm, 0); | |
1530 | mmput(bprm->mm); | |
1531 | } | |
1da177e4 LT |
1532 | |
1533 | out_file: | |
1534 | if (bprm->file) { | |
1535 | allow_write_access(bprm->file); | |
1536 | fput(bprm->file); | |
1537 | } | |
a6f76f23 | 1538 | |
498052bb | 1539 | out_unmark: |
8c652f96 ON |
1540 | if (clear_in_exec) |
1541 | current->fs->in_exec = 0; | |
f9ce1f1c | 1542 | current->in_execve = 0; |
a6f76f23 DH |
1543 | |
1544 | out_free: | |
08a6fac1 | 1545 | free_bprm(bprm); |
1da177e4 | 1546 | |
fd8328be | 1547 | out_files: |
3b125388 AV |
1548 | if (displaced) |
1549 | reset_files_struct(displaced); | |
1da177e4 LT |
1550 | out_ret: |
1551 | return retval; | |
1552 | } | |
1553 | ||
ba2d0162 ON |
1554 | int do_execve(const char *filename, |
1555 | const char __user *const __user *__argv, | |
1556 | const char __user *const __user *__envp, | |
1557 | struct pt_regs *regs) | |
1558 | { | |
0e028465 ON |
1559 | struct user_arg_ptr argv = { .ptr.native = __argv }; |
1560 | struct user_arg_ptr envp = { .ptr.native = __envp }; | |
1561 | return do_execve_common(filename, argv, envp, regs); | |
1562 | } | |
1563 | ||
1564 | #ifdef CONFIG_COMPAT | |
1565 | int compat_do_execve(char *filename, | |
1566 | compat_uptr_t __user *__argv, | |
1567 | compat_uptr_t __user *__envp, | |
1568 | struct pt_regs *regs) | |
1569 | { | |
1570 | struct user_arg_ptr argv = { | |
1571 | .is_compat = true, | |
1572 | .ptr.compat = __argv, | |
1573 | }; | |
1574 | struct user_arg_ptr envp = { | |
1575 | .is_compat = true, | |
1576 | .ptr.compat = __envp, | |
1577 | }; | |
ba2d0162 ON |
1578 | return do_execve_common(filename, argv, envp, regs); |
1579 | } | |
0e028465 | 1580 | #endif |
ba2d0162 | 1581 | |
964ee7df | 1582 | void set_binfmt(struct linux_binfmt *new) |
1da177e4 | 1583 | { |
801460d0 HS |
1584 | struct mm_struct *mm = current->mm; |
1585 | ||
1586 | if (mm->binfmt) | |
1587 | module_put(mm->binfmt->module); | |
1da177e4 | 1588 | |
801460d0 | 1589 | mm->binfmt = new; |
964ee7df ON |
1590 | if (new) |
1591 | __module_get(new->module); | |
1da177e4 LT |
1592 | } |
1593 | ||
1594 | EXPORT_SYMBOL(set_binfmt); | |
1595 | ||
6c5d5238 KH |
1596 | /* |
1597 | * set_dumpable converts traditional three-value dumpable to two flags and | |
1598 | * stores them into mm->flags. It modifies lower two bits of mm->flags, but | |
1599 | * these bits are not changed atomically. So get_dumpable can observe the | |
1600 | * intermediate state. To avoid doing unexpected behavior, get get_dumpable | |
1601 | * return either old dumpable or new one by paying attention to the order of | |
1602 | * modifying the bits. | |
1603 | * | |
1604 | * dumpable | mm->flags (binary) | |
1605 | * old new | initial interim final | |
1606 | * ---------+----------------------- | |
1607 | * 0 1 | 00 01 01 | |
1608 | * 0 2 | 00 10(*) 11 | |
1609 | * 1 0 | 01 00 00 | |
1610 | * 1 2 | 01 11 11 | |
1611 | * 2 0 | 11 10(*) 00 | |
1612 | * 2 1 | 11 11 01 | |
1613 | * | |
1614 | * (*) get_dumpable regards interim value of 10 as 11. | |
1615 | */ | |
1616 | void set_dumpable(struct mm_struct *mm, int value) | |
1617 | { | |
1618 | switch (value) { | |
54b50199 | 1619 | case SUID_DUMPABLE_DISABLED: |
6c5d5238 KH |
1620 | clear_bit(MMF_DUMPABLE, &mm->flags); |
1621 | smp_wmb(); | |
1622 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1623 | break; | |
54b50199 | 1624 | case SUID_DUMPABLE_ENABLED: |
6c5d5238 KH |
1625 | set_bit(MMF_DUMPABLE, &mm->flags); |
1626 | smp_wmb(); | |
1627 | clear_bit(MMF_DUMP_SECURELY, &mm->flags); | |
1628 | break; | |
54b50199 | 1629 | case SUID_DUMPABLE_SAFE: |
6c5d5238 KH |
1630 | set_bit(MMF_DUMP_SECURELY, &mm->flags); |
1631 | smp_wmb(); | |
1632 | set_bit(MMF_DUMPABLE, &mm->flags); | |
1633 | break; | |
1634 | } | |
1635 | } | |
6c5d5238 | 1636 | |
10c28d93 | 1637 | int __get_dumpable(unsigned long mm_flags) |
6c5d5238 KH |
1638 | { |
1639 | int ret; | |
1640 | ||
30736a4d | 1641 | ret = mm_flags & MMF_DUMPABLE_MASK; |
54b50199 | 1642 | return (ret > SUID_DUMPABLE_ENABLED) ? SUID_DUMPABLE_SAFE : ret; |
6c5d5238 KH |
1643 | } |
1644 | ||
30736a4d MH |
1645 | int get_dumpable(struct mm_struct *mm) |
1646 | { | |
1647 | return __get_dumpable(mm->flags); | |
1648 | } |