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> | |
27 | #include <linux/mman.h> | |
28 | #include <linux/a.out.h> | |
29 | #include <linux/stat.h> | |
30 | #include <linux/fcntl.h> | |
31 | #include <linux/smp_lock.h> | |
32 | #include <linux/init.h> | |
33 | #include <linux/pagemap.h> | |
34 | #include <linux/highmem.h> | |
35 | #include <linux/spinlock.h> | |
36 | #include <linux/key.h> | |
37 | #include <linux/personality.h> | |
38 | #include <linux/binfmts.h> | |
39 | #include <linux/swap.h> | |
40 | #include <linux/utsname.h> | |
84d73786 | 41 | #include <linux/pid_namespace.h> |
1da177e4 LT |
42 | #include <linux/module.h> |
43 | #include <linux/namei.h> | |
44 | #include <linux/proc_fs.h> | |
45 | #include <linux/ptrace.h> | |
46 | #include <linux/mount.h> | |
47 | #include <linux/security.h> | |
48 | #include <linux/syscalls.h> | |
49 | #include <linux/rmap.h> | |
8f0ab514 | 50 | #include <linux/tsacct_kern.h> |
9f46080c | 51 | #include <linux/cn_proc.h> |
473ae30b | 52 | #include <linux/audit.h> |
1da177e4 LT |
53 | |
54 | #include <asm/uaccess.h> | |
55 | #include <asm/mmu_context.h> | |
56 | ||
57 | #ifdef CONFIG_KMOD | |
58 | #include <linux/kmod.h> | |
59 | #endif | |
60 | ||
61 | int core_uses_pid; | |
d025c9db | 62 | char core_pattern[128] = "core"; |
d6e71144 AC |
63 | int suid_dumpable = 0; |
64 | ||
65 | EXPORT_SYMBOL(suid_dumpable); | |
1da177e4 LT |
66 | /* The maximal length of core_pattern is also specified in sysctl.c */ |
67 | ||
68 | static struct linux_binfmt *formats; | |
69 | static DEFINE_RWLOCK(binfmt_lock); | |
70 | ||
71 | int register_binfmt(struct linux_binfmt * fmt) | |
72 | { | |
73 | struct linux_binfmt ** tmp = &formats; | |
74 | ||
75 | if (!fmt) | |
76 | return -EINVAL; | |
77 | if (fmt->next) | |
78 | return -EBUSY; | |
79 | write_lock(&binfmt_lock); | |
80 | while (*tmp) { | |
81 | if (fmt == *tmp) { | |
82 | write_unlock(&binfmt_lock); | |
83 | return -EBUSY; | |
84 | } | |
85 | tmp = &(*tmp)->next; | |
86 | } | |
87 | fmt->next = formats; | |
88 | formats = fmt; | |
89 | write_unlock(&binfmt_lock); | |
90 | return 0; | |
91 | } | |
92 | ||
93 | EXPORT_SYMBOL(register_binfmt); | |
94 | ||
95 | int unregister_binfmt(struct linux_binfmt * fmt) | |
96 | { | |
97 | struct linux_binfmt ** tmp = &formats; | |
98 | ||
99 | write_lock(&binfmt_lock); | |
100 | while (*tmp) { | |
101 | if (fmt == *tmp) { | |
102 | *tmp = fmt->next; | |
98701d1b | 103 | fmt->next = NULL; |
1da177e4 LT |
104 | write_unlock(&binfmt_lock); |
105 | return 0; | |
106 | } | |
107 | tmp = &(*tmp)->next; | |
108 | } | |
109 | write_unlock(&binfmt_lock); | |
110 | return -EINVAL; | |
111 | } | |
112 | ||
113 | EXPORT_SYMBOL(unregister_binfmt); | |
114 | ||
115 | static inline void put_binfmt(struct linux_binfmt * fmt) | |
116 | { | |
117 | module_put(fmt->module); | |
118 | } | |
119 | ||
120 | /* | |
121 | * Note that a shared library must be both readable and executable due to | |
122 | * security reasons. | |
123 | * | |
124 | * Also note that we take the address to load from from the file itself. | |
125 | */ | |
126 | asmlinkage long sys_uselib(const char __user * library) | |
127 | { | |
128 | struct file * file; | |
129 | struct nameidata nd; | |
130 | int error; | |
131 | ||
b500531e | 132 | error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); |
1da177e4 LT |
133 | if (error) |
134 | goto out; | |
135 | ||
136 | error = -EINVAL; | |
137 | if (!S_ISREG(nd.dentry->d_inode->i_mode)) | |
138 | goto exit; | |
139 | ||
e4543edd | 140 | error = vfs_permission(&nd, MAY_READ | MAY_EXEC); |
1da177e4 LT |
141 | if (error) |
142 | goto exit; | |
143 | ||
834f2a4a | 144 | file = nameidata_to_filp(&nd, O_RDONLY); |
1da177e4 LT |
145 | error = PTR_ERR(file); |
146 | if (IS_ERR(file)) | |
147 | goto out; | |
148 | ||
149 | error = -ENOEXEC; | |
150 | if(file->f_op) { | |
151 | struct linux_binfmt * fmt; | |
152 | ||
153 | read_lock(&binfmt_lock); | |
154 | for (fmt = formats ; fmt ; fmt = fmt->next) { | |
155 | if (!fmt->load_shlib) | |
156 | continue; | |
157 | if (!try_module_get(fmt->module)) | |
158 | continue; | |
159 | read_unlock(&binfmt_lock); | |
160 | error = fmt->load_shlib(file); | |
161 | read_lock(&binfmt_lock); | |
162 | put_binfmt(fmt); | |
163 | if (error != -ENOEXEC) | |
164 | break; | |
165 | } | |
166 | read_unlock(&binfmt_lock); | |
167 | } | |
168 | fput(file); | |
169 | out: | |
170 | return error; | |
171 | exit: | |
834f2a4a | 172 | release_open_intent(&nd); |
1da177e4 LT |
173 | path_release(&nd); |
174 | goto out; | |
175 | } | |
176 | ||
177 | /* | |
178 | * count() counts the number of strings in array ARGV. | |
179 | */ | |
180 | static int count(char __user * __user * argv, int max) | |
181 | { | |
182 | int i = 0; | |
183 | ||
184 | if (argv != NULL) { | |
185 | for (;;) { | |
186 | char __user * p; | |
187 | ||
188 | if (get_user(p, argv)) | |
189 | return -EFAULT; | |
190 | if (!p) | |
191 | break; | |
192 | argv++; | |
193 | if(++i > max) | |
194 | return -E2BIG; | |
195 | cond_resched(); | |
196 | } | |
197 | } | |
198 | return i; | |
199 | } | |
200 | ||
201 | /* | |
202 | * 'copy_strings()' copies argument/environment strings from user | |
203 | * memory to free pages in kernel mem. These are in a format ready | |
204 | * to be put directly into the top of new user memory. | |
205 | */ | |
75c96f85 AB |
206 | static int copy_strings(int argc, char __user * __user * argv, |
207 | struct linux_binprm *bprm) | |
1da177e4 LT |
208 | { |
209 | struct page *kmapped_page = NULL; | |
210 | char *kaddr = NULL; | |
211 | int ret; | |
212 | ||
213 | while (argc-- > 0) { | |
214 | char __user *str; | |
215 | int len; | |
216 | unsigned long pos; | |
217 | ||
218 | if (get_user(str, argv+argc) || | |
219 | !(len = strnlen_user(str, bprm->p))) { | |
220 | ret = -EFAULT; | |
221 | goto out; | |
222 | } | |
223 | ||
224 | if (bprm->p < len) { | |
225 | ret = -E2BIG; | |
226 | goto out; | |
227 | } | |
228 | ||
229 | bprm->p -= len; | |
230 | /* XXX: add architecture specific overflow check here. */ | |
231 | pos = bprm->p; | |
232 | ||
233 | while (len > 0) { | |
234 | int i, new, err; | |
235 | int offset, bytes_to_copy; | |
236 | struct page *page; | |
237 | ||
238 | offset = pos % PAGE_SIZE; | |
239 | i = pos/PAGE_SIZE; | |
240 | page = bprm->page[i]; | |
241 | new = 0; | |
242 | if (!page) { | |
243 | page = alloc_page(GFP_HIGHUSER); | |
244 | bprm->page[i] = page; | |
245 | if (!page) { | |
246 | ret = -ENOMEM; | |
247 | goto out; | |
248 | } | |
249 | new = 1; | |
250 | } | |
251 | ||
252 | if (page != kmapped_page) { | |
253 | if (kmapped_page) | |
254 | kunmap(kmapped_page); | |
255 | kmapped_page = page; | |
256 | kaddr = kmap(kmapped_page); | |
257 | } | |
258 | if (new && offset) | |
259 | memset(kaddr, 0, offset); | |
260 | bytes_to_copy = PAGE_SIZE - offset; | |
261 | if (bytes_to_copy > len) { | |
262 | bytes_to_copy = len; | |
263 | if (new) | |
264 | memset(kaddr+offset+len, 0, | |
265 | PAGE_SIZE-offset-len); | |
266 | } | |
267 | err = copy_from_user(kaddr+offset, str, bytes_to_copy); | |
268 | if (err) { | |
269 | ret = -EFAULT; | |
270 | goto out; | |
271 | } | |
272 | ||
273 | pos += bytes_to_copy; | |
274 | str += bytes_to_copy; | |
275 | len -= bytes_to_copy; | |
276 | } | |
277 | } | |
278 | ret = 0; | |
279 | out: | |
280 | if (kmapped_page) | |
281 | kunmap(kmapped_page); | |
282 | return ret; | |
283 | } | |
284 | ||
285 | /* | |
286 | * Like copy_strings, but get argv and its values from kernel memory. | |
287 | */ | |
288 | int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) | |
289 | { | |
290 | int r; | |
291 | mm_segment_t oldfs = get_fs(); | |
292 | set_fs(KERNEL_DS); | |
293 | r = copy_strings(argc, (char __user * __user *)argv, bprm); | |
294 | set_fs(oldfs); | |
295 | return r; | |
296 | } | |
297 | ||
298 | EXPORT_SYMBOL(copy_strings_kernel); | |
299 | ||
300 | #ifdef CONFIG_MMU | |
301 | /* | |
302 | * This routine is used to map in a page into an address space: needed by | |
303 | * execve() for the initial stack and environment pages. | |
304 | * | |
305 | * vma->vm_mm->mmap_sem is held for writing. | |
306 | */ | |
307 | void install_arg_page(struct vm_area_struct *vma, | |
308 | struct page *page, unsigned long address) | |
309 | { | |
310 | struct mm_struct *mm = vma->vm_mm; | |
1da177e4 | 311 | pte_t * pte; |
c74df32c | 312 | spinlock_t *ptl; |
1da177e4 LT |
313 | |
314 | if (unlikely(anon_vma_prepare(vma))) | |
c74df32c | 315 | goto out; |
1da177e4 LT |
316 | |
317 | flush_dcache_page(page); | |
c9cfcddf | 318 | pte = get_locked_pte(mm, address, &ptl); |
1da177e4 LT |
319 | if (!pte) |
320 | goto out; | |
321 | if (!pte_none(*pte)) { | |
c74df32c | 322 | pte_unmap_unlock(pte, ptl); |
1da177e4 LT |
323 | goto out; |
324 | } | |
4294621f | 325 | inc_mm_counter(mm, anon_rss); |
1da177e4 LT |
326 | lru_cache_add_active(page); |
327 | set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte( | |
328 | page, vma->vm_page_prot)))); | |
9617d95e | 329 | page_add_new_anon_rmap(page, vma, address); |
c74df32c | 330 | pte_unmap_unlock(pte, ptl); |
1da177e4 LT |
331 | |
332 | /* no need for flush_tlb */ | |
333 | return; | |
334 | out: | |
1da177e4 LT |
335 | __free_page(page); |
336 | force_sig(SIGKILL, current); | |
337 | } | |
338 | ||
339 | #define EXTRA_STACK_VM_PAGES 20 /* random */ | |
340 | ||
341 | int setup_arg_pages(struct linux_binprm *bprm, | |
342 | unsigned long stack_top, | |
343 | int executable_stack) | |
344 | { | |
345 | unsigned long stack_base; | |
346 | struct vm_area_struct *mpnt; | |
347 | struct mm_struct *mm = current->mm; | |
348 | int i, ret; | |
349 | long arg_size; | |
350 | ||
351 | #ifdef CONFIG_STACK_GROWSUP | |
352 | /* Move the argument and environment strings to the bottom of the | |
353 | * stack space. | |
354 | */ | |
355 | int offset, j; | |
356 | char *to, *from; | |
357 | ||
358 | /* Start by shifting all the pages down */ | |
359 | i = 0; | |
360 | for (j = 0; j < MAX_ARG_PAGES; j++) { | |
361 | struct page *page = bprm->page[j]; | |
362 | if (!page) | |
363 | continue; | |
364 | bprm->page[i++] = page; | |
365 | } | |
366 | ||
367 | /* Now move them within their pages */ | |
368 | offset = bprm->p % PAGE_SIZE; | |
369 | to = kmap(bprm->page[0]); | |
370 | for (j = 1; j < i; j++) { | |
371 | memmove(to, to + offset, PAGE_SIZE - offset); | |
372 | from = kmap(bprm->page[j]); | |
373 | memcpy(to + PAGE_SIZE - offset, from, offset); | |
374 | kunmap(bprm->page[j - 1]); | |
375 | to = from; | |
376 | } | |
377 | memmove(to, to + offset, PAGE_SIZE - offset); | |
378 | kunmap(bprm->page[j - 1]); | |
379 | ||
380 | /* Limit stack size to 1GB */ | |
381 | stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max; | |
382 | if (stack_base > (1 << 30)) | |
383 | stack_base = 1 << 30; | |
384 | stack_base = PAGE_ALIGN(stack_top - stack_base); | |
385 | ||
386 | /* Adjust bprm->p to point to the end of the strings. */ | |
387 | bprm->p = stack_base + PAGE_SIZE * i - offset; | |
388 | ||
389 | mm->arg_start = stack_base; | |
390 | arg_size = i << PAGE_SHIFT; | |
391 | ||
392 | /* zero pages that were copied above */ | |
393 | while (i < MAX_ARG_PAGES) | |
394 | bprm->page[i++] = NULL; | |
395 | #else | |
396 | stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE); | |
397 | stack_base = PAGE_ALIGN(stack_base); | |
398 | bprm->p += stack_base; | |
399 | mm->arg_start = bprm->p; | |
400 | arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start); | |
401 | #endif | |
402 | ||
403 | arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE; | |
404 | ||
405 | if (bprm->loader) | |
406 | bprm->loader += stack_base; | |
407 | bprm->exec += stack_base; | |
408 | ||
c3762229 | 409 | mpnt = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); |
1da177e4 LT |
410 | if (!mpnt) |
411 | return -ENOMEM; | |
412 | ||
1da177e4 LT |
413 | down_write(&mm->mmap_sem); |
414 | { | |
415 | mpnt->vm_mm = mm; | |
416 | #ifdef CONFIG_STACK_GROWSUP | |
417 | mpnt->vm_start = stack_base; | |
418 | mpnt->vm_end = stack_base + arg_size; | |
419 | #else | |
420 | mpnt->vm_end = stack_top; | |
421 | mpnt->vm_start = mpnt->vm_end - arg_size; | |
422 | #endif | |
423 | /* Adjust stack execute permissions; explicitly enable | |
424 | * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X | |
425 | * and leave alone (arch default) otherwise. */ | |
426 | if (unlikely(executable_stack == EXSTACK_ENABLE_X)) | |
427 | mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; | |
428 | else if (executable_stack == EXSTACK_DISABLE_X) | |
429 | mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; | |
430 | else | |
431 | mpnt->vm_flags = VM_STACK_FLAGS; | |
432 | mpnt->vm_flags |= mm->def_flags; | |
433 | mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7]; | |
434 | if ((ret = insert_vm_struct(mm, mpnt))) { | |
435 | up_write(&mm->mmap_sem); | |
436 | kmem_cache_free(vm_area_cachep, mpnt); | |
437 | return ret; | |
438 | } | |
439 | mm->stack_vm = mm->total_vm = vma_pages(mpnt); | |
440 | } | |
441 | ||
442 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
443 | struct page *page = bprm->page[i]; | |
444 | if (page) { | |
445 | bprm->page[i] = NULL; | |
446 | install_arg_page(mpnt, page, stack_base); | |
447 | } | |
448 | stack_base += PAGE_SIZE; | |
449 | } | |
450 | up_write(&mm->mmap_sem); | |
451 | ||
452 | return 0; | |
453 | } | |
454 | ||
455 | EXPORT_SYMBOL(setup_arg_pages); | |
456 | ||
457 | #define free_arg_pages(bprm) do { } while (0) | |
458 | ||
459 | #else | |
460 | ||
461 | static inline void free_arg_pages(struct linux_binprm *bprm) | |
462 | { | |
463 | int i; | |
464 | ||
465 | for (i = 0; i < MAX_ARG_PAGES; i++) { | |
466 | if (bprm->page[i]) | |
467 | __free_page(bprm->page[i]); | |
468 | bprm->page[i] = NULL; | |
469 | } | |
470 | } | |
471 | ||
472 | #endif /* CONFIG_MMU */ | |
473 | ||
474 | struct file *open_exec(const char *name) | |
475 | { | |
476 | struct nameidata nd; | |
477 | int err; | |
478 | struct file *file; | |
479 | ||
b500531e | 480 | err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); |
1da177e4 LT |
481 | file = ERR_PTR(err); |
482 | ||
483 | if (!err) { | |
484 | struct inode *inode = nd.dentry->d_inode; | |
485 | file = ERR_PTR(-EACCES); | |
486 | if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && | |
487 | S_ISREG(inode->i_mode)) { | |
e4543edd | 488 | int err = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
489 | file = ERR_PTR(err); |
490 | if (!err) { | |
834f2a4a | 491 | file = nameidata_to_filp(&nd, O_RDONLY); |
1da177e4 LT |
492 | if (!IS_ERR(file)) { |
493 | err = deny_write_access(file); | |
494 | if (err) { | |
495 | fput(file); | |
496 | file = ERR_PTR(err); | |
497 | } | |
498 | } | |
499 | out: | |
500 | return file; | |
501 | } | |
502 | } | |
834f2a4a | 503 | release_open_intent(&nd); |
1da177e4 LT |
504 | path_release(&nd); |
505 | } | |
506 | goto out; | |
507 | } | |
508 | ||
509 | EXPORT_SYMBOL(open_exec); | |
510 | ||
511 | int kernel_read(struct file *file, unsigned long offset, | |
512 | char *addr, unsigned long count) | |
513 | { | |
514 | mm_segment_t old_fs; | |
515 | loff_t pos = offset; | |
516 | int result; | |
517 | ||
518 | old_fs = get_fs(); | |
519 | set_fs(get_ds()); | |
520 | /* The cast to a user pointer is valid due to the set_fs() */ | |
521 | result = vfs_read(file, (void __user *)addr, count, &pos); | |
522 | set_fs(old_fs); | |
523 | return result; | |
524 | } | |
525 | ||
526 | EXPORT_SYMBOL(kernel_read); | |
527 | ||
528 | static int exec_mmap(struct mm_struct *mm) | |
529 | { | |
530 | struct task_struct *tsk; | |
531 | struct mm_struct * old_mm, *active_mm; | |
532 | ||
533 | /* Notify parent that we're no longer interested in the old VM */ | |
534 | tsk = current; | |
535 | old_mm = current->mm; | |
536 | mm_release(tsk, old_mm); | |
537 | ||
538 | if (old_mm) { | |
539 | /* | |
540 | * Make sure that if there is a core dump in progress | |
541 | * for the old mm, we get out and die instead of going | |
542 | * through with the exec. We must hold mmap_sem around | |
543 | * checking core_waiters and changing tsk->mm. The | |
544 | * core-inducing thread will increment core_waiters for | |
545 | * each thread whose ->mm == old_mm. | |
546 | */ | |
547 | down_read(&old_mm->mmap_sem); | |
548 | if (unlikely(old_mm->core_waiters)) { | |
549 | up_read(&old_mm->mmap_sem); | |
550 | return -EINTR; | |
551 | } | |
552 | } | |
553 | task_lock(tsk); | |
554 | active_mm = tsk->active_mm; | |
555 | tsk->mm = mm; | |
556 | tsk->active_mm = mm; | |
557 | activate_mm(active_mm, mm); | |
558 | task_unlock(tsk); | |
559 | arch_pick_mmap_layout(mm); | |
560 | if (old_mm) { | |
561 | up_read(&old_mm->mmap_sem); | |
7dddb12c | 562 | BUG_ON(active_mm != old_mm); |
1da177e4 LT |
563 | mmput(old_mm); |
564 | return 0; | |
565 | } | |
566 | mmdrop(active_mm); | |
567 | return 0; | |
568 | } | |
569 | ||
570 | /* | |
571 | * This function makes sure the current process has its own signal table, | |
572 | * so that flush_signal_handlers can later reset the handlers without | |
573 | * disturbing other processes. (Other processes might share the signal | |
574 | * table via the CLONE_SIGHAND option to clone().) | |
575 | */ | |
858119e1 | 576 | static int de_thread(struct task_struct *tsk) |
1da177e4 LT |
577 | { |
578 | struct signal_struct *sig = tsk->signal; | |
579 | struct sighand_struct *newsighand, *oldsighand = tsk->sighand; | |
580 | spinlock_t *lock = &oldsighand->siglock; | |
329f7dba | 581 | struct task_struct *leader = NULL; |
1da177e4 LT |
582 | int count; |
583 | ||
584 | /* | |
585 | * If we don't share sighandlers, then we aren't sharing anything | |
586 | * and we can just re-use it all. | |
587 | */ | |
588 | if (atomic_read(&oldsighand->count) <= 1) { | |
589 | BUG_ON(atomic_read(&sig->count) != 1); | |
590 | exit_itimers(sig); | |
591 | return 0; | |
592 | } | |
593 | ||
594 | newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); | |
595 | if (!newsighand) | |
596 | return -ENOMEM; | |
597 | ||
aafe6c2a | 598 | if (thread_group_empty(tsk)) |
1da177e4 LT |
599 | goto no_thread_group; |
600 | ||
601 | /* | |
602 | * Kill all other threads in the thread group. | |
603 | * We must hold tasklist_lock to call zap_other_threads. | |
604 | */ | |
605 | read_lock(&tasklist_lock); | |
606 | spin_lock_irq(lock); | |
607 | if (sig->flags & SIGNAL_GROUP_EXIT) { | |
608 | /* | |
609 | * Another group action in progress, just | |
610 | * return so that the signal is processed. | |
611 | */ | |
612 | spin_unlock_irq(lock); | |
613 | read_unlock(&tasklist_lock); | |
614 | kmem_cache_free(sighand_cachep, newsighand); | |
615 | return -EAGAIN; | |
616 | } | |
1434261c ON |
617 | |
618 | /* | |
619 | * child_reaper ignores SIGKILL, change it now. | |
620 | * Reparenting needs write_lock on tasklist_lock, | |
621 | * so it is safe to do it under read_lock. | |
622 | */ | |
84d73786 SB |
623 | if (unlikely(tsk->group_leader == child_reaper(tsk))) |
624 | tsk->nsproxy->pid_ns->child_reaper = tsk; | |
1434261c | 625 | |
aafe6c2a | 626 | zap_other_threads(tsk); |
1da177e4 LT |
627 | read_unlock(&tasklist_lock); |
628 | ||
629 | /* | |
630 | * Account for the thread group leader hanging around: | |
631 | */ | |
9e4e23bc | 632 | count = 1; |
aafe6c2a | 633 | if (!thread_group_leader(tsk)) { |
9e4e23bc | 634 | count = 2; |
53231250 RM |
635 | /* |
636 | * The SIGALRM timer survives the exec, but needs to point | |
637 | * at us as the new group leader now. We have a race with | |
638 | * a timer firing now getting the old leader, so we need to | |
639 | * synchronize with any firing (by calling del_timer_sync) | |
640 | * before we can safely let the old group leader die. | |
641 | */ | |
aafe6c2a | 642 | sig->tsk = tsk; |
932aeafb | 643 | spin_unlock_irq(lock); |
2ff678b8 TG |
644 | if (hrtimer_cancel(&sig->real_timer)) |
645 | hrtimer_restart(&sig->real_timer); | |
932aeafb | 646 | spin_lock_irq(lock); |
53231250 | 647 | } |
1da177e4 | 648 | while (atomic_read(&sig->count) > count) { |
aafe6c2a | 649 | sig->group_exit_task = tsk; |
1da177e4 LT |
650 | sig->notify_count = count; |
651 | __set_current_state(TASK_UNINTERRUPTIBLE); | |
652 | spin_unlock_irq(lock); | |
653 | schedule(); | |
654 | spin_lock_irq(lock); | |
655 | } | |
656 | sig->group_exit_task = NULL; | |
657 | sig->notify_count = 0; | |
658 | spin_unlock_irq(lock); | |
659 | ||
660 | /* | |
661 | * At this point all other threads have exited, all we have to | |
662 | * do is to wait for the thread group leader to become inactive, | |
663 | * and to assume its PID: | |
664 | */ | |
aafe6c2a | 665 | if (!thread_group_leader(tsk)) { |
1da177e4 LT |
666 | /* |
667 | * Wait for the thread group leader to be a zombie. | |
668 | * It should already be zombie at this point, most | |
669 | * of the time. | |
670 | */ | |
aafe6c2a | 671 | leader = tsk->group_leader; |
1da177e4 LT |
672 | while (leader->exit_state != EXIT_ZOMBIE) |
673 | yield(); | |
674 | ||
f5e90281 RM |
675 | /* |
676 | * The only record we have of the real-time age of a | |
677 | * process, regardless of execs it's done, is start_time. | |
678 | * All the past CPU time is accumulated in signal_struct | |
679 | * from sister threads now dead. But in this non-leader | |
680 | * exec, nothing survives from the original leader thread, | |
681 | * whose birth marks the true age of this process now. | |
682 | * When we take on its identity by switching to its PID, we | |
683 | * also take its birthdate (always earlier than our own). | |
684 | */ | |
aafe6c2a | 685 | tsk->start_time = leader->start_time; |
f5e90281 | 686 | |
1da177e4 LT |
687 | write_lock_irq(&tasklist_lock); |
688 | ||
aafe6c2a EB |
689 | BUG_ON(leader->tgid != tsk->tgid); |
690 | BUG_ON(tsk->pid == tsk->tgid); | |
1da177e4 LT |
691 | /* |
692 | * An exec() starts a new thread group with the | |
693 | * TGID of the previous thread group. Rehash the | |
694 | * two threads with a switched PID, and release | |
695 | * the former thread group leader: | |
696 | */ | |
d73d6529 EB |
697 | |
698 | /* Become a process group leader with the old leader's pid. | |
c18258c6 EB |
699 | * The old leader becomes a thread of the this thread group. |
700 | * Note: The old leader also uses this pid until release_task | |
d73d6529 EB |
701 | * is called. Odd but simple and correct. |
702 | */ | |
aafe6c2a EB |
703 | detach_pid(tsk, PIDTYPE_PID); |
704 | tsk->pid = leader->pid; | |
e713d0da | 705 | attach_pid(tsk, PIDTYPE_PID, find_pid(tsk->pid)); |
aafe6c2a EB |
706 | transfer_pid(leader, tsk, PIDTYPE_PGID); |
707 | transfer_pid(leader, tsk, PIDTYPE_SID); | |
708 | list_replace_rcu(&leader->tasks, &tsk->tasks); | |
1da177e4 | 709 | |
aafe6c2a EB |
710 | tsk->group_leader = tsk; |
711 | leader->group_leader = tsk; | |
de12a787 | 712 | |
aafe6c2a | 713 | tsk->exit_signal = SIGCHLD; |
962b564c ON |
714 | |
715 | BUG_ON(leader->exit_state != EXIT_ZOMBIE); | |
716 | leader->exit_state = EXIT_DEAD; | |
1da177e4 LT |
717 | |
718 | write_unlock_irq(&tasklist_lock); | |
1da177e4 LT |
719 | } |
720 | ||
721 | /* | |
fb085cf1 AN |
722 | * There may be one thread left which is just exiting, |
723 | * but it's safe to stop telling the group to kill themselves. | |
1da177e4 LT |
724 | */ |
725 | sig->flags = 0; | |
726 | ||
727 | no_thread_group: | |
1da177e4 | 728 | exit_itimers(sig); |
329f7dba ON |
729 | if (leader) |
730 | release_task(leader); | |
731 | ||
732 | BUG_ON(atomic_read(&sig->count) != 1); | |
1da177e4 LT |
733 | |
734 | if (atomic_read(&oldsighand->count) == 1) { | |
735 | /* | |
736 | * Now that we nuked the rest of the thread group, | |
737 | * it turns out we are not sharing sighand any more either. | |
738 | * So we can just keep it. | |
739 | */ | |
740 | kmem_cache_free(sighand_cachep, newsighand); | |
741 | } else { | |
742 | /* | |
743 | * Move our state over to newsighand and switch it in. | |
744 | */ | |
1da177e4 LT |
745 | atomic_set(&newsighand->count, 1); |
746 | memcpy(newsighand->action, oldsighand->action, | |
747 | sizeof(newsighand->action)); | |
748 | ||
749 | write_lock_irq(&tasklist_lock); | |
750 | spin_lock(&oldsighand->siglock); | |
513627d7 | 751 | spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING); |
1da177e4 | 752 | |
aafe6c2a | 753 | rcu_assign_pointer(tsk->sighand, newsighand); |
1da177e4 LT |
754 | recalc_sigpending(); |
755 | ||
756 | spin_unlock(&newsighand->siglock); | |
757 | spin_unlock(&oldsighand->siglock); | |
758 | write_unlock_irq(&tasklist_lock); | |
759 | ||
760 | if (atomic_dec_and_test(&oldsighand->count)) | |
aa1757f9 | 761 | kmem_cache_free(sighand_cachep, oldsighand); |
1da177e4 LT |
762 | } |
763 | ||
aafe6c2a | 764 | BUG_ON(!thread_group_leader(tsk)); |
1da177e4 LT |
765 | return 0; |
766 | } | |
767 | ||
768 | /* | |
769 | * These functions flushes out all traces of the currently running executable | |
770 | * so that a new one can be started | |
771 | */ | |
772 | ||
858119e1 | 773 | static void flush_old_files(struct files_struct * files) |
1da177e4 LT |
774 | { |
775 | long j = -1; | |
badf1662 | 776 | struct fdtable *fdt; |
1da177e4 LT |
777 | |
778 | spin_lock(&files->file_lock); | |
779 | for (;;) { | |
780 | unsigned long set, i; | |
781 | ||
782 | j++; | |
783 | i = j * __NFDBITS; | |
badf1662 | 784 | fdt = files_fdtable(files); |
bbea9f69 | 785 | if (i >= fdt->max_fds) |
1da177e4 | 786 | break; |
badf1662 | 787 | set = fdt->close_on_exec->fds_bits[j]; |
1da177e4 LT |
788 | if (!set) |
789 | continue; | |
badf1662 | 790 | fdt->close_on_exec->fds_bits[j] = 0; |
1da177e4 LT |
791 | spin_unlock(&files->file_lock); |
792 | for ( ; set ; i++,set >>= 1) { | |
793 | if (set & 1) { | |
794 | sys_close(i); | |
795 | } | |
796 | } | |
797 | spin_lock(&files->file_lock); | |
798 | ||
799 | } | |
800 | spin_unlock(&files->file_lock); | |
801 | } | |
802 | ||
803 | void get_task_comm(char *buf, struct task_struct *tsk) | |
804 | { | |
805 | /* buf must be at least sizeof(tsk->comm) in size */ | |
806 | task_lock(tsk); | |
807 | strncpy(buf, tsk->comm, sizeof(tsk->comm)); | |
808 | task_unlock(tsk); | |
809 | } | |
810 | ||
811 | void set_task_comm(struct task_struct *tsk, char *buf) | |
812 | { | |
813 | task_lock(tsk); | |
814 | strlcpy(tsk->comm, buf, sizeof(tsk->comm)); | |
815 | task_unlock(tsk); | |
816 | } | |
817 | ||
818 | int flush_old_exec(struct linux_binprm * bprm) | |
819 | { | |
820 | char * name; | |
821 | int i, ch, retval; | |
822 | struct files_struct *files; | |
823 | char tcomm[sizeof(current->comm)]; | |
824 | ||
825 | /* | |
826 | * Make sure we have a private signal table and that | |
827 | * we are unassociated from the previous thread group. | |
828 | */ | |
829 | retval = de_thread(current); | |
830 | if (retval) | |
831 | goto out; | |
832 | ||
833 | /* | |
834 | * Make sure we have private file handles. Ask the | |
835 | * fork helper to do the work for us and the exit | |
836 | * helper to do the cleanup of the old one. | |
837 | */ | |
838 | files = current->files; /* refcounted so safe to hold */ | |
839 | retval = unshare_files(); | |
840 | if (retval) | |
841 | goto out; | |
842 | /* | |
843 | * Release all of the old mmap stuff | |
844 | */ | |
845 | retval = exec_mmap(bprm->mm); | |
846 | if (retval) | |
847 | goto mmap_failed; | |
848 | ||
849 | bprm->mm = NULL; /* We're using it now */ | |
850 | ||
851 | /* This is the point of no return */ | |
1da177e4 LT |
852 | put_files_struct(files); |
853 | ||
854 | current->sas_ss_sp = current->sas_ss_size = 0; | |
855 | ||
856 | if (current->euid == current->uid && current->egid == current->gid) | |
857 | current->mm->dumpable = 1; | |
d6e71144 AC |
858 | else |
859 | current->mm->dumpable = suid_dumpable; | |
860 | ||
1da177e4 | 861 | name = bprm->filename; |
36772092 PBG |
862 | |
863 | /* Copies the binary name from after last slash */ | |
1da177e4 LT |
864 | for (i=0; (ch = *(name++)) != '\0';) { |
865 | if (ch == '/') | |
36772092 | 866 | i = 0; /* overwrite what we wrote */ |
1da177e4 LT |
867 | else |
868 | if (i < (sizeof(tcomm) - 1)) | |
869 | tcomm[i++] = ch; | |
870 | } | |
871 | tcomm[i] = '\0'; | |
872 | set_task_comm(current, tcomm); | |
873 | ||
874 | current->flags &= ~PF_RANDOMIZE; | |
875 | flush_thread(); | |
876 | ||
0551fbd2 BH |
877 | /* Set the new mm task size. We have to do that late because it may |
878 | * depend on TIF_32BIT which is only updated in flush_thread() on | |
879 | * some architectures like powerpc | |
880 | */ | |
881 | current->mm->task_size = TASK_SIZE; | |
882 | ||
1da177e4 | 883 | if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || |
8c744fb8 | 884 | file_permission(bprm->file, MAY_READ) || |
1da177e4 LT |
885 | (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { |
886 | suid_keys(current); | |
d6e71144 | 887 | current->mm->dumpable = suid_dumpable; |
1da177e4 LT |
888 | } |
889 | ||
890 | /* An exec changes our domain. We are no longer part of the thread | |
891 | group */ | |
892 | ||
893 | current->self_exec_id++; | |
894 | ||
895 | flush_signal_handlers(current, 0); | |
896 | flush_old_files(current->files); | |
897 | ||
898 | return 0; | |
899 | ||
900 | mmap_failed: | |
3b9b8ab6 | 901 | reset_files_struct(current, files); |
1da177e4 LT |
902 | out: |
903 | return retval; | |
904 | } | |
905 | ||
906 | EXPORT_SYMBOL(flush_old_exec); | |
907 | ||
908 | /* | |
909 | * Fill the binprm structure from the inode. | |
910 | * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes | |
911 | */ | |
912 | int prepare_binprm(struct linux_binprm *bprm) | |
913 | { | |
914 | int mode; | |
0f7fc9e4 | 915 | struct inode * inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
916 | int retval; |
917 | ||
918 | mode = inode->i_mode; | |
1da177e4 LT |
919 | if (bprm->file->f_op == NULL) |
920 | return -EACCES; | |
921 | ||
922 | bprm->e_uid = current->euid; | |
923 | bprm->e_gid = current->egid; | |
924 | ||
0f7fc9e4 | 925 | if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { |
1da177e4 LT |
926 | /* Set-uid? */ |
927 | if (mode & S_ISUID) { | |
928 | current->personality &= ~PER_CLEAR_ON_SETID; | |
929 | bprm->e_uid = inode->i_uid; | |
930 | } | |
931 | ||
932 | /* Set-gid? */ | |
933 | /* | |
934 | * If setgid is set but no group execute bit then this | |
935 | * is a candidate for mandatory locking, not a setgid | |
936 | * executable. | |
937 | */ | |
938 | if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { | |
939 | current->personality &= ~PER_CLEAR_ON_SETID; | |
940 | bprm->e_gid = inode->i_gid; | |
941 | } | |
942 | } | |
943 | ||
944 | /* fill in binprm security blob */ | |
945 | retval = security_bprm_set(bprm); | |
946 | if (retval) | |
947 | return retval; | |
948 | ||
949 | memset(bprm->buf,0,BINPRM_BUF_SIZE); | |
950 | return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); | |
951 | } | |
952 | ||
953 | EXPORT_SYMBOL(prepare_binprm); | |
954 | ||
858119e1 | 955 | static int unsafe_exec(struct task_struct *p) |
1da177e4 LT |
956 | { |
957 | int unsafe = 0; | |
958 | if (p->ptrace & PT_PTRACED) { | |
959 | if (p->ptrace & PT_PTRACE_CAP) | |
960 | unsafe |= LSM_UNSAFE_PTRACE_CAP; | |
961 | else | |
962 | unsafe |= LSM_UNSAFE_PTRACE; | |
963 | } | |
964 | if (atomic_read(&p->fs->count) > 1 || | |
965 | atomic_read(&p->files->count) > 1 || | |
966 | atomic_read(&p->sighand->count) > 1) | |
967 | unsafe |= LSM_UNSAFE_SHARE; | |
968 | ||
969 | return unsafe; | |
970 | } | |
971 | ||
972 | void compute_creds(struct linux_binprm *bprm) | |
973 | { | |
974 | int unsafe; | |
975 | ||
976 | if (bprm->e_uid != current->uid) | |
977 | suid_keys(current); | |
978 | exec_keys(current); | |
979 | ||
980 | task_lock(current); | |
981 | unsafe = unsafe_exec(current); | |
982 | security_bprm_apply_creds(bprm, unsafe); | |
983 | task_unlock(current); | |
984 | security_bprm_post_apply_creds(bprm); | |
985 | } | |
1da177e4 LT |
986 | EXPORT_SYMBOL(compute_creds); |
987 | ||
4fc75ff4 NP |
988 | /* |
989 | * Arguments are '\0' separated strings found at the location bprm->p | |
990 | * points to; chop off the first by relocating brpm->p to right after | |
991 | * the first '\0' encountered. | |
992 | */ | |
1da177e4 LT |
993 | void remove_arg_zero(struct linux_binprm *bprm) |
994 | { | |
995 | if (bprm->argc) { | |
4fc75ff4 NP |
996 | char ch; |
997 | ||
998 | do { | |
999 | unsigned long offset; | |
1000 | unsigned long index; | |
1001 | char *kaddr; | |
1002 | struct page *page; | |
1da177e4 | 1003 | |
4fc75ff4 NP |
1004 | offset = bprm->p & ~PAGE_MASK; |
1005 | index = bprm->p >> PAGE_SHIFT; | |
1da177e4 | 1006 | |
4fc75ff4 | 1007 | page = bprm->page[index]; |
1da177e4 | 1008 | kaddr = kmap_atomic(page, KM_USER0); |
4fc75ff4 NP |
1009 | |
1010 | /* run through page until we reach end or find NUL */ | |
1011 | do { | |
1012 | ch = *(kaddr + offset); | |
1013 | ||
1014 | /* discard that character... */ | |
1015 | bprm->p++; | |
1016 | offset++; | |
1017 | } while (offset < PAGE_SIZE && ch != '\0'); | |
1018 | ||
1019 | kunmap_atomic(kaddr, KM_USER0); | |
1020 | ||
1021 | /* free the old page */ | |
1022 | if (offset == PAGE_SIZE) { | |
1023 | __free_page(page); | |
1024 | bprm->page[index] = NULL; | |
1025 | } | |
1026 | } while (ch != '\0'); | |
1027 | ||
1da177e4 LT |
1028 | bprm->argc--; |
1029 | } | |
1030 | } | |
1da177e4 LT |
1031 | EXPORT_SYMBOL(remove_arg_zero); |
1032 | ||
1033 | /* | |
1034 | * cycle the list of binary formats handler, until one recognizes the image | |
1035 | */ | |
1036 | int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) | |
1037 | { | |
1038 | int try,retval; | |
1039 | struct linux_binfmt *fmt; | |
1040 | #ifdef __alpha__ | |
1041 | /* handle /sbin/loader.. */ | |
1042 | { | |
1043 | struct exec * eh = (struct exec *) bprm->buf; | |
1044 | ||
1045 | if (!bprm->loader && eh->fh.f_magic == 0x183 && | |
1046 | (eh->fh.f_flags & 0x3000) == 0x3000) | |
1047 | { | |
1048 | struct file * file; | |
1049 | unsigned long loader; | |
1050 | ||
1051 | allow_write_access(bprm->file); | |
1052 | fput(bprm->file); | |
1053 | bprm->file = NULL; | |
1054 | ||
1055 | loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); | |
1056 | ||
1057 | file = open_exec("/sbin/loader"); | |
1058 | retval = PTR_ERR(file); | |
1059 | if (IS_ERR(file)) | |
1060 | return retval; | |
1061 | ||
1062 | /* Remember if the application is TASO. */ | |
1063 | bprm->sh_bang = eh->ah.entry < 0x100000000UL; | |
1064 | ||
1065 | bprm->file = file; | |
1066 | bprm->loader = loader; | |
1067 | retval = prepare_binprm(bprm); | |
1068 | if (retval<0) | |
1069 | return retval; | |
1070 | /* should call search_binary_handler recursively here, | |
1071 | but it does not matter */ | |
1072 | } | |
1073 | } | |
1074 | #endif | |
1075 | retval = security_bprm_check(bprm); | |
1076 | if (retval) | |
1077 | return retval; | |
1078 | ||
1079 | /* kernel module loader fixup */ | |
1080 | /* so we don't try to load run modprobe in kernel space. */ | |
1081 | set_fs(USER_DS); | |
473ae30b AV |
1082 | |
1083 | retval = audit_bprm(bprm); | |
1084 | if (retval) | |
1085 | return retval; | |
1086 | ||
1da177e4 LT |
1087 | retval = -ENOENT; |
1088 | for (try=0; try<2; try++) { | |
1089 | read_lock(&binfmt_lock); | |
1090 | for (fmt = formats ; fmt ; fmt = fmt->next) { | |
1091 | int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; | |
1092 | if (!fn) | |
1093 | continue; | |
1094 | if (!try_module_get(fmt->module)) | |
1095 | continue; | |
1096 | read_unlock(&binfmt_lock); | |
1097 | retval = fn(bprm, regs); | |
1098 | if (retval >= 0) { | |
1099 | put_binfmt(fmt); | |
1100 | allow_write_access(bprm->file); | |
1101 | if (bprm->file) | |
1102 | fput(bprm->file); | |
1103 | bprm->file = NULL; | |
1104 | current->did_exec = 1; | |
9f46080c | 1105 | proc_exec_connector(current); |
1da177e4 LT |
1106 | return retval; |
1107 | } | |
1108 | read_lock(&binfmt_lock); | |
1109 | put_binfmt(fmt); | |
1110 | if (retval != -ENOEXEC || bprm->mm == NULL) | |
1111 | break; | |
1112 | if (!bprm->file) { | |
1113 | read_unlock(&binfmt_lock); | |
1114 | return retval; | |
1115 | } | |
1116 | } | |
1117 | read_unlock(&binfmt_lock); | |
1118 | if (retval != -ENOEXEC || bprm->mm == NULL) { | |
1119 | break; | |
1120 | #ifdef CONFIG_KMOD | |
1121 | }else{ | |
1122 | #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) | |
1123 | if (printable(bprm->buf[0]) && | |
1124 | printable(bprm->buf[1]) && | |
1125 | printable(bprm->buf[2]) && | |
1126 | printable(bprm->buf[3])) | |
1127 | break; /* -ENOEXEC */ | |
1128 | request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); | |
1129 | #endif | |
1130 | } | |
1131 | } | |
1132 | return retval; | |
1133 | } | |
1134 | ||
1135 | EXPORT_SYMBOL(search_binary_handler); | |
1136 | ||
1137 | /* | |
1138 | * sys_execve() executes a new program. | |
1139 | */ | |
1140 | int do_execve(char * filename, | |
1141 | char __user *__user *argv, | |
1142 | char __user *__user *envp, | |
1143 | struct pt_regs * regs) | |
1144 | { | |
1145 | struct linux_binprm *bprm; | |
1146 | struct file *file; | |
1147 | int retval; | |
1148 | int i; | |
1149 | ||
1150 | retval = -ENOMEM; | |
11b0b5ab | 1151 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); |
1da177e4 LT |
1152 | if (!bprm) |
1153 | goto out_ret; | |
1da177e4 LT |
1154 | |
1155 | file = open_exec(filename); | |
1156 | retval = PTR_ERR(file); | |
1157 | if (IS_ERR(file)) | |
1158 | goto out_kfree; | |
1159 | ||
1160 | sched_exec(); | |
1161 | ||
1162 | bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); | |
1163 | ||
1164 | bprm->file = file; | |
1165 | bprm->filename = filename; | |
1166 | bprm->interp = filename; | |
1167 | bprm->mm = mm_alloc(); | |
1168 | retval = -ENOMEM; | |
1169 | if (!bprm->mm) | |
1170 | goto out_file; | |
1171 | ||
1172 | retval = init_new_context(current, bprm->mm); | |
1173 | if (retval < 0) | |
1174 | goto out_mm; | |
1175 | ||
1176 | bprm->argc = count(argv, bprm->p / sizeof(void *)); | |
1177 | if ((retval = bprm->argc) < 0) | |
1178 | goto out_mm; | |
1179 | ||
1180 | bprm->envc = count(envp, bprm->p / sizeof(void *)); | |
1181 | if ((retval = bprm->envc) < 0) | |
1182 | goto out_mm; | |
1183 | ||
1184 | retval = security_bprm_alloc(bprm); | |
1185 | if (retval) | |
1186 | goto out; | |
1187 | ||
1188 | retval = prepare_binprm(bprm); | |
1189 | if (retval < 0) | |
1190 | goto out; | |
1191 | ||
1192 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | |
1193 | if (retval < 0) | |
1194 | goto out; | |
1195 | ||
1196 | bprm->exec = bprm->p; | |
1197 | retval = copy_strings(bprm->envc, envp, bprm); | |
1198 | if (retval < 0) | |
1199 | goto out; | |
1200 | ||
1201 | retval = copy_strings(bprm->argc, argv, bprm); | |
1202 | if (retval < 0) | |
1203 | goto out; | |
1204 | ||
1205 | retval = search_binary_handler(bprm,regs); | |
1206 | if (retval >= 0) { | |
1207 | free_arg_pages(bprm); | |
1208 | ||
1209 | /* execve success */ | |
1210 | security_bprm_free(bprm); | |
1211 | acct_update_integrals(current); | |
1da177e4 LT |
1212 | kfree(bprm); |
1213 | return retval; | |
1214 | } | |
1215 | ||
1216 | out: | |
1217 | /* Something went wrong, return the inode and free the argument pages*/ | |
1218 | for (i = 0 ; i < MAX_ARG_PAGES ; i++) { | |
1219 | struct page * page = bprm->page[i]; | |
1220 | if (page) | |
1221 | __free_page(page); | |
1222 | } | |
1223 | ||
1224 | if (bprm->security) | |
1225 | security_bprm_free(bprm); | |
1226 | ||
1227 | out_mm: | |
1228 | if (bprm->mm) | |
1229 | mmdrop(bprm->mm); | |
1230 | ||
1231 | out_file: | |
1232 | if (bprm->file) { | |
1233 | allow_write_access(bprm->file); | |
1234 | fput(bprm->file); | |
1235 | } | |
1236 | ||
1237 | out_kfree: | |
1238 | kfree(bprm); | |
1239 | ||
1240 | out_ret: | |
1241 | return retval; | |
1242 | } | |
1243 | ||
1244 | int set_binfmt(struct linux_binfmt *new) | |
1245 | { | |
1246 | struct linux_binfmt *old = current->binfmt; | |
1247 | ||
1248 | if (new) { | |
1249 | if (!try_module_get(new->module)) | |
1250 | return -1; | |
1251 | } | |
1252 | current->binfmt = new; | |
1253 | if (old) | |
1254 | module_put(old->module); | |
1255 | return 0; | |
1256 | } | |
1257 | ||
1258 | EXPORT_SYMBOL(set_binfmt); | |
1259 | ||
1260 | #define CORENAME_MAX_SIZE 64 | |
1261 | ||
1262 | /* format_corename will inspect the pattern parameter, and output a | |
1263 | * name into corename, which must have space for at least | |
1264 | * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. | |
1265 | */ | |
c4bbafda | 1266 | static int format_corename(char *corename, const char *pattern, long signr) |
1da177e4 LT |
1267 | { |
1268 | const char *pat_ptr = pattern; | |
1269 | char *out_ptr = corename; | |
1270 | char *const out_end = corename + CORENAME_MAX_SIZE; | |
1271 | int rc; | |
1272 | int pid_in_pattern = 0; | |
c4bbafda AC |
1273 | int ispipe = 0; |
1274 | ||
1275 | if (*pattern == '|') | |
1276 | ispipe = 1; | |
1da177e4 LT |
1277 | |
1278 | /* Repeat as long as we have more pattern to process and more output | |
1279 | space */ | |
1280 | while (*pat_ptr) { | |
1281 | if (*pat_ptr != '%') { | |
1282 | if (out_ptr == out_end) | |
1283 | goto out; | |
1284 | *out_ptr++ = *pat_ptr++; | |
1285 | } else { | |
1286 | switch (*++pat_ptr) { | |
1287 | case 0: | |
1288 | goto out; | |
1289 | /* Double percent, output one percent */ | |
1290 | case '%': | |
1291 | if (out_ptr == out_end) | |
1292 | goto out; | |
1293 | *out_ptr++ = '%'; | |
1294 | break; | |
1295 | /* pid */ | |
1296 | case 'p': | |
1297 | pid_in_pattern = 1; | |
1298 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1299 | "%d", current->tgid); | |
1300 | if (rc > out_end - out_ptr) | |
1301 | goto out; | |
1302 | out_ptr += rc; | |
1303 | break; | |
1304 | /* uid */ | |
1305 | case 'u': | |
1306 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1307 | "%d", current->uid); | |
1308 | if (rc > out_end - out_ptr) | |
1309 | goto out; | |
1310 | out_ptr += rc; | |
1311 | break; | |
1312 | /* gid */ | |
1313 | case 'g': | |
1314 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1315 | "%d", current->gid); | |
1316 | if (rc > out_end - out_ptr) | |
1317 | goto out; | |
1318 | out_ptr += rc; | |
1319 | break; | |
1320 | /* signal that caused the coredump */ | |
1321 | case 's': | |
1322 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1323 | "%ld", signr); | |
1324 | if (rc > out_end - out_ptr) | |
1325 | goto out; | |
1326 | out_ptr += rc; | |
1327 | break; | |
1328 | /* UNIX time of coredump */ | |
1329 | case 't': { | |
1330 | struct timeval tv; | |
1331 | do_gettimeofday(&tv); | |
1332 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1333 | "%lu", tv.tv_sec); | |
1334 | if (rc > out_end - out_ptr) | |
1335 | goto out; | |
1336 | out_ptr += rc; | |
1337 | break; | |
1338 | } | |
1339 | /* hostname */ | |
1340 | case 'h': | |
1341 | down_read(&uts_sem); | |
1342 | rc = snprintf(out_ptr, out_end - out_ptr, | |
e9ff3990 | 1343 | "%s", utsname()->nodename); |
1da177e4 LT |
1344 | up_read(&uts_sem); |
1345 | if (rc > out_end - out_ptr) | |
1346 | goto out; | |
1347 | out_ptr += rc; | |
1348 | break; | |
1349 | /* executable */ | |
1350 | case 'e': | |
1351 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1352 | "%s", current->comm); | |
1353 | if (rc > out_end - out_ptr) | |
1354 | goto out; | |
1355 | out_ptr += rc; | |
1356 | break; | |
1357 | default: | |
1358 | break; | |
1359 | } | |
1360 | ++pat_ptr; | |
1361 | } | |
1362 | } | |
1363 | /* Backward compatibility with core_uses_pid: | |
1364 | * | |
1365 | * If core_pattern does not include a %p (as is the default) | |
1366 | * and core_uses_pid is set, then .%pid will be appended to | |
c4bbafda AC |
1367 | * the filename. Do not do this for piped commands. */ |
1368 | if (!ispipe && !pid_in_pattern | |
1da177e4 LT |
1369 | && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) { |
1370 | rc = snprintf(out_ptr, out_end - out_ptr, | |
1371 | ".%d", current->tgid); | |
1372 | if (rc > out_end - out_ptr) | |
1373 | goto out; | |
1374 | out_ptr += rc; | |
1375 | } | |
c4bbafda | 1376 | out: |
1da177e4 | 1377 | *out_ptr = 0; |
c4bbafda | 1378 | return ispipe; |
1da177e4 LT |
1379 | } |
1380 | ||
d5f70c00 | 1381 | static void zap_process(struct task_struct *start) |
aceecc04 ON |
1382 | { |
1383 | struct task_struct *t; | |
281de339 | 1384 | |
d5f70c00 ON |
1385 | start->signal->flags = SIGNAL_GROUP_EXIT; |
1386 | start->signal->group_stop_count = 0; | |
aceecc04 ON |
1387 | |
1388 | t = start; | |
1389 | do { | |
1390 | if (t != current && t->mm) { | |
1391 | t->mm->core_waiters++; | |
281de339 ON |
1392 | sigaddset(&t->pending.signal, SIGKILL); |
1393 | signal_wake_up(t, 1); | |
aceecc04 ON |
1394 | } |
1395 | } while ((t = next_thread(t)) != start); | |
1396 | } | |
1397 | ||
dcf560c5 ON |
1398 | static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, |
1399 | int exit_code) | |
1da177e4 LT |
1400 | { |
1401 | struct task_struct *g, *p; | |
5debfa6d | 1402 | unsigned long flags; |
dcf560c5 ON |
1403 | int err = -EAGAIN; |
1404 | ||
1405 | spin_lock_irq(&tsk->sighand->siglock); | |
1406 | if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) { | |
dcf560c5 | 1407 | tsk->signal->group_exit_code = exit_code; |
5debfa6d | 1408 | zap_process(tsk); |
dcf560c5 | 1409 | err = 0; |
1da177e4 | 1410 | } |
dcf560c5 ON |
1411 | spin_unlock_irq(&tsk->sighand->siglock); |
1412 | if (err) | |
1413 | return err; | |
1da177e4 | 1414 | |
5debfa6d ON |
1415 | if (atomic_read(&mm->mm_users) == mm->core_waiters + 1) |
1416 | goto done; | |
1417 | ||
7b1c6154 | 1418 | rcu_read_lock(); |
aceecc04 | 1419 | for_each_process(g) { |
5debfa6d ON |
1420 | if (g == tsk->group_leader) |
1421 | continue; | |
1422 | ||
aceecc04 ON |
1423 | p = g; |
1424 | do { | |
1425 | if (p->mm) { | |
5debfa6d ON |
1426 | if (p->mm == mm) { |
1427 | /* | |
1428 | * p->sighand can't disappear, but | |
1429 | * may be changed by de_thread() | |
1430 | */ | |
1431 | lock_task_sighand(p, &flags); | |
d5f70c00 | 1432 | zap_process(p); |
5debfa6d ON |
1433 | unlock_task_sighand(p, &flags); |
1434 | } | |
aceecc04 ON |
1435 | break; |
1436 | } | |
1437 | } while ((p = next_thread(p)) != g); | |
1438 | } | |
7b1c6154 | 1439 | rcu_read_unlock(); |
5debfa6d | 1440 | done: |
dcf560c5 | 1441 | return mm->core_waiters; |
1da177e4 LT |
1442 | } |
1443 | ||
dcf560c5 | 1444 | static int coredump_wait(int exit_code) |
1da177e4 | 1445 | { |
dcf560c5 ON |
1446 | struct task_struct *tsk = current; |
1447 | struct mm_struct *mm = tsk->mm; | |
1448 | struct completion startup_done; | |
1449 | struct completion *vfork_done; | |
2384f55f | 1450 | int core_waiters; |
1da177e4 | 1451 | |
dcf560c5 ON |
1452 | init_completion(&mm->core_done); |
1453 | init_completion(&startup_done); | |
1da177e4 LT |
1454 | mm->core_startup_done = &startup_done; |
1455 | ||
dcf560c5 | 1456 | core_waiters = zap_threads(tsk, mm, exit_code); |
2384f55f ON |
1457 | up_write(&mm->mmap_sem); |
1458 | ||
dcf560c5 ON |
1459 | if (unlikely(core_waiters < 0)) |
1460 | goto fail; | |
1461 | ||
1462 | /* | |
1463 | * Make sure nobody is waiting for us to release the VM, | |
1464 | * otherwise we can deadlock when we wait on each other | |
1465 | */ | |
1466 | vfork_done = tsk->vfork_done; | |
1467 | if (vfork_done) { | |
1468 | tsk->vfork_done = NULL; | |
1469 | complete(vfork_done); | |
1470 | } | |
1471 | ||
2384f55f | 1472 | if (core_waiters) |
1da177e4 | 1473 | wait_for_completion(&startup_done); |
dcf560c5 | 1474 | fail: |
1da177e4 | 1475 | BUG_ON(mm->core_waiters); |
dcf560c5 | 1476 | return core_waiters; |
1da177e4 LT |
1477 | } |
1478 | ||
1479 | int do_coredump(long signr, int exit_code, struct pt_regs * regs) | |
1480 | { | |
1481 | char corename[CORENAME_MAX_SIZE + 1]; | |
1482 | struct mm_struct *mm = current->mm; | |
1483 | struct linux_binfmt * binfmt; | |
1484 | struct inode * inode; | |
1485 | struct file * file; | |
1486 | int retval = 0; | |
d6e71144 AC |
1487 | int fsuid = current->fsuid; |
1488 | int flag = 0; | |
d025c9db | 1489 | int ispipe = 0; |
1da177e4 LT |
1490 | |
1491 | binfmt = current->binfmt; | |
1492 | if (!binfmt || !binfmt->core_dump) | |
1493 | goto fail; | |
1494 | down_write(&mm->mmap_sem); | |
1495 | if (!mm->dumpable) { | |
1496 | up_write(&mm->mmap_sem); | |
1497 | goto fail; | |
1498 | } | |
d6e71144 AC |
1499 | |
1500 | /* | |
1501 | * We cannot trust fsuid as being the "true" uid of the | |
1502 | * process nor do we know its entire history. We only know it | |
1503 | * was tainted so we dump it as root in mode 2. | |
1504 | */ | |
1505 | if (mm->dumpable == 2) { /* Setuid core dump mode */ | |
1506 | flag = O_EXCL; /* Stop rewrite attacks */ | |
1507 | current->fsuid = 0; /* Dump root private */ | |
1508 | } | |
1da177e4 | 1509 | mm->dumpable = 0; |
1291cf41 | 1510 | |
dcf560c5 ON |
1511 | retval = coredump_wait(exit_code); |
1512 | if (retval < 0) | |
1291cf41 | 1513 | goto fail; |
1da177e4 LT |
1514 | |
1515 | /* | |
1516 | * Clear any false indication of pending signals that might | |
1517 | * be seen by the filesystem code called to write the core file. | |
1518 | */ | |
1da177e4 LT |
1519 | clear_thread_flag(TIF_SIGPENDING); |
1520 | ||
1521 | if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump) | |
1522 | goto fail_unlock; | |
1523 | ||
1524 | /* | |
1525 | * lock_kernel() because format_corename() is controlled by sysctl, which | |
1526 | * uses lock_kernel() | |
1527 | */ | |
1528 | lock_kernel(); | |
c4bbafda | 1529 | ispipe = format_corename(corename, core_pattern, signr); |
1da177e4 | 1530 | unlock_kernel(); |
c4bbafda | 1531 | if (ispipe) { |
d025c9db AK |
1532 | /* SIGPIPE can happen, but it's just never processed */ |
1533 | if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) { | |
1534 | printk(KERN_INFO "Core dump to %s pipe failed\n", | |
1535 | corename); | |
1536 | goto fail_unlock; | |
1537 | } | |
d025c9db AK |
1538 | } else |
1539 | file = filp_open(corename, | |
6d4df677 AD |
1540 | O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, |
1541 | 0600); | |
1da177e4 LT |
1542 | if (IS_ERR(file)) |
1543 | goto fail_unlock; | |
0f7fc9e4 | 1544 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1545 | if (inode->i_nlink > 1) |
1546 | goto close_fail; /* multiple links - don't dump */ | |
0f7fc9e4 | 1547 | if (!ispipe && d_unhashed(file->f_path.dentry)) |
1da177e4 LT |
1548 | goto close_fail; |
1549 | ||
d025c9db AK |
1550 | /* AK: actually i see no reason to not allow this for named pipes etc., |
1551 | but keep the previous behaviour for now. */ | |
1552 | if (!ispipe && !S_ISREG(inode->i_mode)) | |
1da177e4 LT |
1553 | goto close_fail; |
1554 | if (!file->f_op) | |
1555 | goto close_fail; | |
1556 | if (!file->f_op->write) | |
1557 | goto close_fail; | |
0f7fc9e4 | 1558 | if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0) |
1da177e4 LT |
1559 | goto close_fail; |
1560 | ||
1561 | retval = binfmt->core_dump(signr, regs, file); | |
1562 | ||
1563 | if (retval) | |
1564 | current->signal->group_exit_code |= 0x80; | |
1565 | close_fail: | |
1566 | filp_close(file, NULL); | |
1567 | fail_unlock: | |
d6e71144 | 1568 | current->fsuid = fsuid; |
1da177e4 LT |
1569 | complete_all(&mm->core_done); |
1570 | fail: | |
1571 | return retval; | |
1572 | } |