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 25 #include <linux/config.h> 26 #include <linux/slab.h> 27 #include <linux/file.h> 28 #include <linux/mman.h> 29 #include <linux/a.out.h> 30 #include <linux/stat.h> 31 #include <linux/fcntl.h> 32 #include <linux/smp_lock.h> 33 #include <linux/init.h> 34 #include <linux/pagemap.h> 35 #include <linux/highmem.h> 36 #include <linux/spinlock.h> 37 #include <linux/key.h> 38 #include <linux/personality.h> 39 #include <linux/binfmts.h> 40 #include <linux/swap.h> 41 #include <linux/utsname.h> 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> 50 #include <linux/acct.h> 51 #include <linux/cn_proc.h> 52 #include <linux/audit.h> 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; 62 char core_pattern[65] = "core"; 63 int suid_dumpable = 0; 64 65 EXPORT_SYMBOL(suid_dumpable); 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; 103 write_unlock(&binfmt_lock); 104 return 0; 105 } 106 tmp = &(*tmp)->next; 107 } 108 write_unlock(&binfmt_lock); 109 return -EINVAL; 110 } 111 112 EXPORT_SYMBOL(unregister_binfmt); 113 114 static inline void put_binfmt(struct linux_binfmt * fmt) 115 { 116 module_put(fmt->module); 117 } 118 119 /* 120 * Note that a shared library must be both readable and executable due to 121 * security reasons. 122 * 123 * Also note that we take the address to load from from the file itself. 124 */ 125 asmlinkage long sys_uselib(const char __user * library) 126 { 127 struct file * file; 128 struct nameidata nd; 129 int error; 130 131 error = __user_path_lookup_open(library, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); 132 if (error) 133 goto out; 134 135 error = -EINVAL; 136 if (!S_ISREG(nd.dentry->d_inode->i_mode)) 137 goto exit; 138 139 error = vfs_permission(&nd, MAY_READ | MAY_EXEC); 140 if (error) 141 goto exit; 142 143 file = nameidata_to_filp(&nd, O_RDONLY); 144 error = PTR_ERR(file); 145 if (IS_ERR(file)) 146 goto out; 147 148 error = -ENOEXEC; 149 if(file->f_op) { 150 struct linux_binfmt * fmt; 151 152 read_lock(&binfmt_lock); 153 for (fmt = formats ; fmt ; fmt = fmt->next) { 154 if (!fmt->load_shlib) 155 continue; 156 if (!try_module_get(fmt->module)) 157 continue; 158 read_unlock(&binfmt_lock); 159 error = fmt->load_shlib(file); 160 read_lock(&binfmt_lock); 161 put_binfmt(fmt); 162 if (error != -ENOEXEC) 163 break; 164 } 165 read_unlock(&binfmt_lock); 166 } 167 fput(file); 168 out: 169 return error; 170 exit: 171 release_open_intent(&nd); 172 path_release(&nd); 173 goto out; 174 } 175 176 /* 177 * count() counts the number of strings in array ARGV. 178 */ 179 static int count(char __user * __user * argv, int max) 180 { 181 int i = 0; 182 183 if (argv != NULL) { 184 for (;;) { 185 char __user * p; 186 187 if (get_user(p, argv)) 188 return -EFAULT; 189 if (!p) 190 break; 191 argv++; 192 if(++i > max) 193 return -E2BIG; 194 cond_resched(); 195 } 196 } 197 return i; 198 } 199 200 /* 201 * 'copy_strings()' copies argument/environment strings from user 202 * memory to free pages in kernel mem. These are in a format ready 203 * to be put directly into the top of new user memory. 204 */ 205 static int copy_strings(int argc, char __user * __user * argv, 206 struct linux_binprm *bprm) 207 { 208 struct page *kmapped_page = NULL; 209 char *kaddr = NULL; 210 int ret; 211 212 while (argc-- > 0) { 213 char __user *str; 214 int len; 215 unsigned long pos; 216 217 if (get_user(str, argv+argc) || 218 !(len = strnlen_user(str, bprm->p))) { 219 ret = -EFAULT; 220 goto out; 221 } 222 223 if (bprm->p < len) { 224 ret = -E2BIG; 225 goto out; 226 } 227 228 bprm->p -= len; 229 /* XXX: add architecture specific overflow check here. */ 230 pos = bprm->p; 231 232 while (len > 0) { 233 int i, new, err; 234 int offset, bytes_to_copy; 235 struct page *page; 236 237 offset = pos % PAGE_SIZE; 238 i = pos/PAGE_SIZE; 239 page = bprm->page[i]; 240 new = 0; 241 if (!page) { 242 page = alloc_page(GFP_HIGHUSER); 243 bprm->page[i] = page; 244 if (!page) { 245 ret = -ENOMEM; 246 goto out; 247 } 248 new = 1; 249 } 250 251 if (page != kmapped_page) { 252 if (kmapped_page) 253 kunmap(kmapped_page); 254 kmapped_page = page; 255 kaddr = kmap(kmapped_page); 256 } 257 if (new && offset) 258 memset(kaddr, 0, offset); 259 bytes_to_copy = PAGE_SIZE - offset; 260 if (bytes_to_copy > len) { 261 bytes_to_copy = len; 262 if (new) 263 memset(kaddr+offset+len, 0, 264 PAGE_SIZE-offset-len); 265 } 266 err = copy_from_user(kaddr+offset, str, bytes_to_copy); 267 if (err) { 268 ret = -EFAULT; 269 goto out; 270 } 271 272 pos += bytes_to_copy; 273 str += bytes_to_copy; 274 len -= bytes_to_copy; 275 } 276 } 277 ret = 0; 278 out: 279 if (kmapped_page) 280 kunmap(kmapped_page); 281 return ret; 282 } 283 284 /* 285 * Like copy_strings, but get argv and its values from kernel memory. 286 */ 287 int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) 288 { 289 int r; 290 mm_segment_t oldfs = get_fs(); 291 set_fs(KERNEL_DS); 292 r = copy_strings(argc, (char __user * __user *)argv, bprm); 293 set_fs(oldfs); 294 return r; 295 } 296 297 EXPORT_SYMBOL(copy_strings_kernel); 298 299 #ifdef CONFIG_MMU 300 /* 301 * This routine is used to map in a page into an address space: needed by 302 * execve() for the initial stack and environment pages. 303 * 304 * vma->vm_mm->mmap_sem is held for writing. 305 */ 306 void install_arg_page(struct vm_area_struct *vma, 307 struct page *page, unsigned long address) 308 { 309 struct mm_struct *mm = vma->vm_mm; 310 pte_t * pte; 311 spinlock_t *ptl; 312 313 if (unlikely(anon_vma_prepare(vma))) 314 goto out; 315 316 flush_dcache_page(page); 317 pte = get_locked_pte(mm, address, &ptl); 318 if (!pte) 319 goto out; 320 if (!pte_none(*pte)) { 321 pte_unmap_unlock(pte, ptl); 322 goto out; 323 } 324 inc_mm_counter(mm, anon_rss); 325 lru_cache_add_active(page); 326 set_pte_at(mm, address, pte, pte_mkdirty(pte_mkwrite(mk_pte( 327 page, vma->vm_page_prot)))); 328 page_add_new_anon_rmap(page, vma, address); 329 pte_unmap_unlock(pte, ptl); 330 331 /* no need for flush_tlb */ 332 return; 333 out: 334 __free_page(page); 335 force_sig(SIGKILL, current); 336 } 337 338 #define EXTRA_STACK_VM_PAGES 20 /* random */ 339 340 int setup_arg_pages(struct linux_binprm *bprm, 341 unsigned long stack_top, 342 int executable_stack) 343 { 344 unsigned long stack_base; 345 struct vm_area_struct *mpnt; 346 struct mm_struct *mm = current->mm; 347 int i, ret; 348 long arg_size; 349 350 #ifdef CONFIG_STACK_GROWSUP 351 /* Move the argument and environment strings to the bottom of the 352 * stack space. 353 */ 354 int offset, j; 355 char *to, *from; 356 357 /* Start by shifting all the pages down */ 358 i = 0; 359 for (j = 0; j < MAX_ARG_PAGES; j++) { 360 struct page *page = bprm->page[j]; 361 if (!page) 362 continue; 363 bprm->page[i++] = page; 364 } 365 366 /* Now move them within their pages */ 367 offset = bprm->p % PAGE_SIZE; 368 to = kmap(bprm->page[0]); 369 for (j = 1; j < i; j++) { 370 memmove(to, to + offset, PAGE_SIZE - offset); 371 from = kmap(bprm->page[j]); 372 memcpy(to + PAGE_SIZE - offset, from, offset); 373 kunmap(bprm->page[j - 1]); 374 to = from; 375 } 376 memmove(to, to + offset, PAGE_SIZE - offset); 377 kunmap(bprm->page[j - 1]); 378 379 /* Limit stack size to 1GB */ 380 stack_base = current->signal->rlim[RLIMIT_STACK].rlim_max; 381 if (stack_base > (1 << 30)) 382 stack_base = 1 << 30; 383 stack_base = PAGE_ALIGN(stack_top - stack_base); 384 385 /* Adjust bprm->p to point to the end of the strings. */ 386 bprm->p = stack_base + PAGE_SIZE * i - offset; 387 388 mm->arg_start = stack_base; 389 arg_size = i << PAGE_SHIFT; 390 391 /* zero pages that were copied above */ 392 while (i < MAX_ARG_PAGES) 393 bprm->page[i++] = NULL; 394 #else 395 stack_base = arch_align_stack(stack_top - MAX_ARG_PAGES*PAGE_SIZE); 396 stack_base = PAGE_ALIGN(stack_base); 397 bprm->p += stack_base; 398 mm->arg_start = bprm->p; 399 arg_size = stack_top - (PAGE_MASK & (unsigned long) mm->arg_start); 400 #endif 401 402 arg_size += EXTRA_STACK_VM_PAGES * PAGE_SIZE; 403 404 if (bprm->loader) 405 bprm->loader += stack_base; 406 bprm->exec += stack_base; 407 408 mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); 409 if (!mpnt) 410 return -ENOMEM; 411 412 memset(mpnt, 0, sizeof(*mpnt)); 413 414 down_write(&mm->mmap_sem); 415 { 416 mpnt->vm_mm = mm; 417 #ifdef CONFIG_STACK_GROWSUP 418 mpnt->vm_start = stack_base; 419 mpnt->vm_end = stack_base + arg_size; 420 #else 421 mpnt->vm_end = stack_top; 422 mpnt->vm_start = mpnt->vm_end - arg_size; 423 #endif 424 /* Adjust stack execute permissions; explicitly enable 425 * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X 426 * and leave alone (arch default) otherwise. */ 427 if (unlikely(executable_stack == EXSTACK_ENABLE_X)) 428 mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; 429 else if (executable_stack == EXSTACK_DISABLE_X) 430 mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; 431 else 432 mpnt->vm_flags = VM_STACK_FLAGS; 433 mpnt->vm_flags |= mm->def_flags; 434 mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7]; 435 if ((ret = insert_vm_struct(mm, mpnt))) { 436 up_write(&mm->mmap_sem); 437 kmem_cache_free(vm_area_cachep, mpnt); 438 return ret; 439 } 440 mm->stack_vm = mm->total_vm = vma_pages(mpnt); 441 } 442 443 for (i = 0 ; i < MAX_ARG_PAGES ; i++) { 444 struct page *page = bprm->page[i]; 445 if (page) { 446 bprm->page[i] = NULL; 447 install_arg_page(mpnt, page, stack_base); 448 } 449 stack_base += PAGE_SIZE; 450 } 451 up_write(&mm->mmap_sem); 452 453 return 0; 454 } 455 456 EXPORT_SYMBOL(setup_arg_pages); 457 458 #define free_arg_pages(bprm) do { } while (0) 459 460 #else 461 462 static inline void free_arg_pages(struct linux_binprm *bprm) 463 { 464 int i; 465 466 for (i = 0; i < MAX_ARG_PAGES; i++) { 467 if (bprm->page[i]) 468 __free_page(bprm->page[i]); 469 bprm->page[i] = NULL; 470 } 471 } 472 473 #endif /* CONFIG_MMU */ 474 475 struct file *open_exec(const char *name) 476 { 477 struct nameidata nd; 478 int err; 479 struct file *file; 480 481 err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); 482 file = ERR_PTR(err); 483 484 if (!err) { 485 struct inode *inode = nd.dentry->d_inode; 486 file = ERR_PTR(-EACCES); 487 if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && 488 S_ISREG(inode->i_mode)) { 489 int err = vfs_permission(&nd, MAY_EXEC); 490 if (!err && !(inode->i_mode & 0111)) 491 err = -EACCES; 492 file = ERR_PTR(err); 493 if (!err) { 494 file = nameidata_to_filp(&nd, O_RDONLY); 495 if (!IS_ERR(file)) { 496 err = deny_write_access(file); 497 if (err) { 498 fput(file); 499 file = ERR_PTR(err); 500 } 501 } 502 out: 503 return file; 504 } 505 } 506 release_open_intent(&nd); 507 path_release(&nd); 508 } 509 goto out; 510 } 511 512 EXPORT_SYMBOL(open_exec); 513 514 int kernel_read(struct file *file, unsigned long offset, 515 char *addr, unsigned long count) 516 { 517 mm_segment_t old_fs; 518 loff_t pos = offset; 519 int result; 520 521 old_fs = get_fs(); 522 set_fs(get_ds()); 523 /* The cast to a user pointer is valid due to the set_fs() */ 524 result = vfs_read(file, (void __user *)addr, count, &pos); 525 set_fs(old_fs); 526 return result; 527 } 528 529 EXPORT_SYMBOL(kernel_read); 530 531 static int exec_mmap(struct mm_struct *mm) 532 { 533 struct task_struct *tsk; 534 struct mm_struct * old_mm, *active_mm; 535 536 /* Notify parent that we're no longer interested in the old VM */ 537 tsk = current; 538 old_mm = current->mm; 539 mm_release(tsk, old_mm); 540 541 if (old_mm) { 542 /* 543 * Make sure that if there is a core dump in progress 544 * for the old mm, we get out and die instead of going 545 * through with the exec. We must hold mmap_sem around 546 * checking core_waiters and changing tsk->mm. The 547 * core-inducing thread will increment core_waiters for 548 * each thread whose ->mm == old_mm. 549 */ 550 down_read(&old_mm->mmap_sem); 551 if (unlikely(old_mm->core_waiters)) { 552 up_read(&old_mm->mmap_sem); 553 return -EINTR; 554 } 555 } 556 task_lock(tsk); 557 active_mm = tsk->active_mm; 558 tsk->mm = mm; 559 tsk->active_mm = mm; 560 activate_mm(active_mm, mm); 561 task_unlock(tsk); 562 arch_pick_mmap_layout(mm); 563 if (old_mm) { 564 up_read(&old_mm->mmap_sem); 565 BUG_ON(active_mm != old_mm); 566 mmput(old_mm); 567 return 0; 568 } 569 mmdrop(active_mm); 570 return 0; 571 } 572 573 /* 574 * This function makes sure the current process has its own signal table, 575 * so that flush_signal_handlers can later reset the handlers without 576 * disturbing other processes. (Other processes might share the signal 577 * table via the CLONE_SIGHAND option to clone().) 578 */ 579 static int de_thread(struct task_struct *tsk) 580 { 581 struct signal_struct *sig = tsk->signal; 582 struct sighand_struct *newsighand, *oldsighand = tsk->sighand; 583 spinlock_t *lock = &oldsighand->siglock; 584 struct task_struct *leader = NULL; 585 int count; 586 587 /* 588 * If we don't share sighandlers, then we aren't sharing anything 589 * and we can just re-use it all. 590 */ 591 if (atomic_read(&oldsighand->count) <= 1) { 592 BUG_ON(atomic_read(&sig->count) != 1); 593 exit_itimers(sig); 594 return 0; 595 } 596 597 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); 598 if (!newsighand) 599 return -ENOMEM; 600 601 if (thread_group_empty(current)) 602 goto no_thread_group; 603 604 /* 605 * Kill all other threads in the thread group. 606 * We must hold tasklist_lock to call zap_other_threads. 607 */ 608 read_lock(&tasklist_lock); 609 spin_lock_irq(lock); 610 if (sig->flags & SIGNAL_GROUP_EXIT) { 611 /* 612 * Another group action in progress, just 613 * return so that the signal is processed. 614 */ 615 spin_unlock_irq(lock); 616 read_unlock(&tasklist_lock); 617 kmem_cache_free(sighand_cachep, newsighand); 618 return -EAGAIN; 619 } 620 621 /* 622 * child_reaper ignores SIGKILL, change it now. 623 * Reparenting needs write_lock on tasklist_lock, 624 * so it is safe to do it under read_lock. 625 */ 626 if (unlikely(current->group_leader == child_reaper)) 627 child_reaper = current; 628 629 zap_other_threads(current); 630 read_unlock(&tasklist_lock); 631 632 /* 633 * Account for the thread group leader hanging around: 634 */ 635 count = 1; 636 if (!thread_group_leader(current)) { 637 count = 2; 638 /* 639 * The SIGALRM timer survives the exec, but needs to point 640 * at us as the new group leader now. We have a race with 641 * a timer firing now getting the old leader, so we need to 642 * synchronize with any firing (by calling del_timer_sync) 643 * before we can safely let the old group leader die. 644 */ 645 sig->tsk = current; 646 spin_unlock_irq(lock); 647 if (hrtimer_cancel(&sig->real_timer)) 648 hrtimer_restart(&sig->real_timer); 649 spin_lock_irq(lock); 650 } 651 while (atomic_read(&sig->count) > count) { 652 sig->group_exit_task = current; 653 sig->notify_count = count; 654 __set_current_state(TASK_UNINTERRUPTIBLE); 655 spin_unlock_irq(lock); 656 schedule(); 657 spin_lock_irq(lock); 658 } 659 sig->group_exit_task = NULL; 660 sig->notify_count = 0; 661 spin_unlock_irq(lock); 662 663 /* 664 * At this point all other threads have exited, all we have to 665 * do is to wait for the thread group leader to become inactive, 666 * and to assume its PID: 667 */ 668 if (!thread_group_leader(current)) { 669 struct dentry *proc_dentry1, *proc_dentry2; 670 671 /* 672 * Wait for the thread group leader to be a zombie. 673 * It should already be zombie at this point, most 674 * of the time. 675 */ 676 leader = current->group_leader; 677 while (leader->exit_state != EXIT_ZOMBIE) 678 yield(); 679 680 /* 681 * The only record we have of the real-time age of a 682 * process, regardless of execs it's done, is start_time. 683 * All the past CPU time is accumulated in signal_struct 684 * from sister threads now dead. But in this non-leader 685 * exec, nothing survives from the original leader thread, 686 * whose birth marks the true age of this process now. 687 * When we take on its identity by switching to its PID, we 688 * also take its birthdate (always earlier than our own). 689 */ 690 current->start_time = leader->start_time; 691 692 spin_lock(&leader->proc_lock); 693 spin_lock(¤t->proc_lock); 694 proc_dentry1 = proc_pid_unhash(current); 695 proc_dentry2 = proc_pid_unhash(leader); 696 write_lock_irq(&tasklist_lock); 697 698 BUG_ON(leader->tgid != current->tgid); 699 BUG_ON(current->pid == current->tgid); 700 /* 701 * An exec() starts a new thread group with the 702 * TGID of the previous thread group. Rehash the 703 * two threads with a switched PID, and release 704 * the former thread group leader: 705 */ 706 707 /* Become a process group leader with the old leader's pid. 708 * Note: The old leader also uses thispid until release_task 709 * is called. Odd but simple and correct. 710 */ 711 detach_pid(current, PIDTYPE_PID); 712 current->pid = leader->pid; 713 attach_pid(current, PIDTYPE_PID, current->pid); 714 attach_pid(current, PIDTYPE_PGID, current->signal->pgrp); 715 attach_pid(current, PIDTYPE_SID, current->signal->session); 716 list_add_tail_rcu(¤t->tasks, &init_task.tasks); 717 718 current->group_leader = current; 719 leader->group_leader = current; 720 721 /* Reduce leader to a thread */ 722 detach_pid(leader, PIDTYPE_PGID); 723 detach_pid(leader, PIDTYPE_SID); 724 list_del_init(&leader->tasks); 725 726 current->exit_signal = SIGCHLD; 727 728 BUG_ON(leader->exit_state != EXIT_ZOMBIE); 729 leader->exit_state = EXIT_DEAD; 730 731 write_unlock_irq(&tasklist_lock); 732 spin_unlock(&leader->proc_lock); 733 spin_unlock(¤t->proc_lock); 734 proc_pid_flush(proc_dentry1); 735 proc_pid_flush(proc_dentry2); 736 } 737 738 /* 739 * There may be one thread left which is just exiting, 740 * but it's safe to stop telling the group to kill themselves. 741 */ 742 sig->flags = 0; 743 744 no_thread_group: 745 exit_itimers(sig); 746 if (leader) 747 release_task(leader); 748 749 BUG_ON(atomic_read(&sig->count) != 1); 750 751 if (atomic_read(&oldsighand->count) == 1) { 752 /* 753 * Now that we nuked the rest of the thread group, 754 * it turns out we are not sharing sighand any more either. 755 * So we can just keep it. 756 */ 757 kmem_cache_free(sighand_cachep, newsighand); 758 } else { 759 /* 760 * Move our state over to newsighand and switch it in. 761 */ 762 atomic_set(&newsighand->count, 1); 763 memcpy(newsighand->action, oldsighand->action, 764 sizeof(newsighand->action)); 765 766 write_lock_irq(&tasklist_lock); 767 spin_lock(&oldsighand->siglock); 768 spin_lock(&newsighand->siglock); 769 770 rcu_assign_pointer(current->sighand, newsighand); 771 recalc_sigpending(); 772 773 spin_unlock(&newsighand->siglock); 774 spin_unlock(&oldsighand->siglock); 775 write_unlock_irq(&tasklist_lock); 776 777 if (atomic_dec_and_test(&oldsighand->count)) 778 kmem_cache_free(sighand_cachep, oldsighand); 779 } 780 781 BUG_ON(!thread_group_leader(current)); 782 return 0; 783 } 784 785 /* 786 * These functions flushes out all traces of the currently running executable 787 * so that a new one can be started 788 */ 789 790 static void flush_old_files(struct files_struct * files) 791 { 792 long j = -1; 793 struct fdtable *fdt; 794 795 spin_lock(&files->file_lock); 796 for (;;) { 797 unsigned long set, i; 798 799 j++; 800 i = j * __NFDBITS; 801 fdt = files_fdtable(files); 802 if (i >= fdt->max_fds || i >= fdt->max_fdset) 803 break; 804 set = fdt->close_on_exec->fds_bits[j]; 805 if (!set) 806 continue; 807 fdt->close_on_exec->fds_bits[j] = 0; 808 spin_unlock(&files->file_lock); 809 for ( ; set ; i++,set >>= 1) { 810 if (set & 1) { 811 sys_close(i); 812 } 813 } 814 spin_lock(&files->file_lock); 815 816 } 817 spin_unlock(&files->file_lock); 818 } 819 820 void get_task_comm(char *buf, struct task_struct *tsk) 821 { 822 /* buf must be at least sizeof(tsk->comm) in size */ 823 task_lock(tsk); 824 strncpy(buf, tsk->comm, sizeof(tsk->comm)); 825 task_unlock(tsk); 826 } 827 828 void set_task_comm(struct task_struct *tsk, char *buf) 829 { 830 task_lock(tsk); 831 strlcpy(tsk->comm, buf, sizeof(tsk->comm)); 832 task_unlock(tsk); 833 } 834 835 int flush_old_exec(struct linux_binprm * bprm) 836 { 837 char * name; 838 int i, ch, retval; 839 struct files_struct *files; 840 char tcomm[sizeof(current->comm)]; 841 842 /* 843 * Make sure we have a private signal table and that 844 * we are unassociated from the previous thread group. 845 */ 846 retval = de_thread(current); 847 if (retval) 848 goto out; 849 850 /* 851 * Make sure we have private file handles. Ask the 852 * fork helper to do the work for us and the exit 853 * helper to do the cleanup of the old one. 854 */ 855 files = current->files; /* refcounted so safe to hold */ 856 retval = unshare_files(); 857 if (retval) 858 goto out; 859 /* 860 * Release all of the old mmap stuff 861 */ 862 retval = exec_mmap(bprm->mm); 863 if (retval) 864 goto mmap_failed; 865 866 bprm->mm = NULL; /* We're using it now */ 867 868 /* This is the point of no return */ 869 put_files_struct(files); 870 871 current->sas_ss_sp = current->sas_ss_size = 0; 872 873 if (current->euid == current->uid && current->egid == current->gid) 874 current->mm->dumpable = 1; 875 else 876 current->mm->dumpable = suid_dumpable; 877 878 name = bprm->filename; 879 880 /* Copies the binary name from after last slash */ 881 for (i=0; (ch = *(name++)) != '\0';) { 882 if (ch == '/') 883 i = 0; /* overwrite what we wrote */ 884 else 885 if (i < (sizeof(tcomm) - 1)) 886 tcomm[i++] = ch; 887 } 888 tcomm[i] = '\0'; 889 set_task_comm(current, tcomm); 890 891 current->flags &= ~PF_RANDOMIZE; 892 flush_thread(); 893 894 /* Set the new mm task size. We have to do that late because it may 895 * depend on TIF_32BIT which is only updated in flush_thread() on 896 * some architectures like powerpc 897 */ 898 current->mm->task_size = TASK_SIZE; 899 900 if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || 901 file_permission(bprm->file, MAY_READ) || 902 (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { 903 suid_keys(current); 904 current->mm->dumpable = suid_dumpable; 905 } 906 907 /* An exec changes our domain. We are no longer part of the thread 908 group */ 909 910 current->self_exec_id++; 911 912 flush_signal_handlers(current, 0); 913 flush_old_files(current->files); 914 915 return 0; 916 917 mmap_failed: 918 put_files_struct(current->files); 919 current->files = files; 920 out: 921 return retval; 922 } 923 924 EXPORT_SYMBOL(flush_old_exec); 925 926 /* 927 * Fill the binprm structure from the inode. 928 * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes 929 */ 930 int prepare_binprm(struct linux_binprm *bprm) 931 { 932 int mode; 933 struct inode * inode = bprm->file->f_dentry->d_inode; 934 int retval; 935 936 mode = inode->i_mode; 937 /* 938 * Check execute perms again - if the caller has CAP_DAC_OVERRIDE, 939 * generic_permission lets a non-executable through 940 */ 941 if (!(mode & 0111)) /* with at least _one_ execute bit set */ 942 return -EACCES; 943 if (bprm->file->f_op == NULL) 944 return -EACCES; 945 946 bprm->e_uid = current->euid; 947 bprm->e_gid = current->egid; 948 949 if(!(bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)) { 950 /* Set-uid? */ 951 if (mode & S_ISUID) { 952 current->personality &= ~PER_CLEAR_ON_SETID; 953 bprm->e_uid = inode->i_uid; 954 } 955 956 /* Set-gid? */ 957 /* 958 * If setgid is set but no group execute bit then this 959 * is a candidate for mandatory locking, not a setgid 960 * executable. 961 */ 962 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { 963 current->personality &= ~PER_CLEAR_ON_SETID; 964 bprm->e_gid = inode->i_gid; 965 } 966 } 967 968 /* fill in binprm security blob */ 969 retval = security_bprm_set(bprm); 970 if (retval) 971 return retval; 972 973 memset(bprm->buf,0,BINPRM_BUF_SIZE); 974 return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); 975 } 976 977 EXPORT_SYMBOL(prepare_binprm); 978 979 static int unsafe_exec(struct task_struct *p) 980 { 981 int unsafe = 0; 982 if (p->ptrace & PT_PTRACED) { 983 if (p->ptrace & PT_PTRACE_CAP) 984 unsafe |= LSM_UNSAFE_PTRACE_CAP; 985 else 986 unsafe |= LSM_UNSAFE_PTRACE; 987 } 988 if (atomic_read(&p->fs->count) > 1 || 989 atomic_read(&p->files->count) > 1 || 990 atomic_read(&p->sighand->count) > 1) 991 unsafe |= LSM_UNSAFE_SHARE; 992 993 return unsafe; 994 } 995 996 void compute_creds(struct linux_binprm *bprm) 997 { 998 int unsafe; 999 1000 if (bprm->e_uid != current->uid) 1001 suid_keys(current); 1002 exec_keys(current); 1003 1004 task_lock(current); 1005 unsafe = unsafe_exec(current); 1006 security_bprm_apply_creds(bprm, unsafe); 1007 task_unlock(current); 1008 security_bprm_post_apply_creds(bprm); 1009 } 1010 1011 EXPORT_SYMBOL(compute_creds); 1012 1013 void remove_arg_zero(struct linux_binprm *bprm) 1014 { 1015 if (bprm->argc) { 1016 unsigned long offset; 1017 char * kaddr; 1018 struct page *page; 1019 1020 offset = bprm->p % PAGE_SIZE; 1021 goto inside; 1022 1023 while (bprm->p++, *(kaddr+offset++)) { 1024 if (offset != PAGE_SIZE) 1025 continue; 1026 offset = 0; 1027 kunmap_atomic(kaddr, KM_USER0); 1028 inside: 1029 page = bprm->page[bprm->p/PAGE_SIZE]; 1030 kaddr = kmap_atomic(page, KM_USER0); 1031 } 1032 kunmap_atomic(kaddr, KM_USER0); 1033 bprm->argc--; 1034 } 1035 } 1036 1037 EXPORT_SYMBOL(remove_arg_zero); 1038 1039 /* 1040 * cycle the list of binary formats handler, until one recognizes the image 1041 */ 1042 int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) 1043 { 1044 int try,retval; 1045 struct linux_binfmt *fmt; 1046 #ifdef __alpha__ 1047 /* handle /sbin/loader.. */ 1048 { 1049 struct exec * eh = (struct exec *) bprm->buf; 1050 1051 if (!bprm->loader && eh->fh.f_magic == 0x183 && 1052 (eh->fh.f_flags & 0x3000) == 0x3000) 1053 { 1054 struct file * file; 1055 unsigned long loader; 1056 1057 allow_write_access(bprm->file); 1058 fput(bprm->file); 1059 bprm->file = NULL; 1060 1061 loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); 1062 1063 file = open_exec("/sbin/loader"); 1064 retval = PTR_ERR(file); 1065 if (IS_ERR(file)) 1066 return retval; 1067 1068 /* Remember if the application is TASO. */ 1069 bprm->sh_bang = eh->ah.entry < 0x100000000UL; 1070 1071 bprm->file = file; 1072 bprm->loader = loader; 1073 retval = prepare_binprm(bprm); 1074 if (retval<0) 1075 return retval; 1076 /* should call search_binary_handler recursively here, 1077 but it does not matter */ 1078 } 1079 } 1080 #endif 1081 retval = security_bprm_check(bprm); 1082 if (retval) 1083 return retval; 1084 1085 /* kernel module loader fixup */ 1086 /* so we don't try to load run modprobe in kernel space. */ 1087 set_fs(USER_DS); 1088 1089 retval = audit_bprm(bprm); 1090 if (retval) 1091 return retval; 1092 1093 retval = -ENOENT; 1094 for (try=0; try<2; try++) { 1095 read_lock(&binfmt_lock); 1096 for (fmt = formats ; fmt ; fmt = fmt->next) { 1097 int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; 1098 if (!fn) 1099 continue; 1100 if (!try_module_get(fmt->module)) 1101 continue; 1102 read_unlock(&binfmt_lock); 1103 retval = fn(bprm, regs); 1104 if (retval >= 0) { 1105 put_binfmt(fmt); 1106 allow_write_access(bprm->file); 1107 if (bprm->file) 1108 fput(bprm->file); 1109 bprm->file = NULL; 1110 current->did_exec = 1; 1111 proc_exec_connector(current); 1112 return retval; 1113 } 1114 read_lock(&binfmt_lock); 1115 put_binfmt(fmt); 1116 if (retval != -ENOEXEC || bprm->mm == NULL) 1117 break; 1118 if (!bprm->file) { 1119 read_unlock(&binfmt_lock); 1120 return retval; 1121 } 1122 } 1123 read_unlock(&binfmt_lock); 1124 if (retval != -ENOEXEC || bprm->mm == NULL) { 1125 break; 1126 #ifdef CONFIG_KMOD 1127 }else{ 1128 #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) 1129 if (printable(bprm->buf[0]) && 1130 printable(bprm->buf[1]) && 1131 printable(bprm->buf[2]) && 1132 printable(bprm->buf[3])) 1133 break; /* -ENOEXEC */ 1134 request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); 1135 #endif 1136 } 1137 } 1138 return retval; 1139 } 1140 1141 EXPORT_SYMBOL(search_binary_handler); 1142 1143 /* 1144 * sys_execve() executes a new program. 1145 */ 1146 int do_execve(char * filename, 1147 char __user *__user *argv, 1148 char __user *__user *envp, 1149 struct pt_regs * regs) 1150 { 1151 struct linux_binprm *bprm; 1152 struct file *file; 1153 int retval; 1154 int i; 1155 1156 retval = -ENOMEM; 1157 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); 1158 if (!bprm) 1159 goto out_ret; 1160 1161 file = open_exec(filename); 1162 retval = PTR_ERR(file); 1163 if (IS_ERR(file)) 1164 goto out_kfree; 1165 1166 sched_exec(); 1167 1168 bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); 1169 1170 bprm->file = file; 1171 bprm->filename = filename; 1172 bprm->interp = filename; 1173 bprm->mm = mm_alloc(); 1174 retval = -ENOMEM; 1175 if (!bprm->mm) 1176 goto out_file; 1177 1178 retval = init_new_context(current, bprm->mm); 1179 if (retval < 0) 1180 goto out_mm; 1181 1182 bprm->argc = count(argv, bprm->p / sizeof(void *)); 1183 if ((retval = bprm->argc) < 0) 1184 goto out_mm; 1185 1186 bprm->envc = count(envp, bprm->p / sizeof(void *)); 1187 if ((retval = bprm->envc) < 0) 1188 goto out_mm; 1189 1190 retval = security_bprm_alloc(bprm); 1191 if (retval) 1192 goto out; 1193 1194 retval = prepare_binprm(bprm); 1195 if (retval < 0) 1196 goto out; 1197 1198 retval = copy_strings_kernel(1, &bprm->filename, bprm); 1199 if (retval < 0) 1200 goto out; 1201 1202 bprm->exec = bprm->p; 1203 retval = copy_strings(bprm->envc, envp, bprm); 1204 if (retval < 0) 1205 goto out; 1206 1207 retval = copy_strings(bprm->argc, argv, bprm); 1208 if (retval < 0) 1209 goto out; 1210 1211 retval = search_binary_handler(bprm,regs); 1212 if (retval >= 0) { 1213 free_arg_pages(bprm); 1214 1215 /* execve success */ 1216 security_bprm_free(bprm); 1217 acct_update_integrals(current); 1218 kfree(bprm); 1219 return retval; 1220 } 1221 1222 out: 1223 /* Something went wrong, return the inode and free the argument pages*/ 1224 for (i = 0 ; i < MAX_ARG_PAGES ; i++) { 1225 struct page * page = bprm->page[i]; 1226 if (page) 1227 __free_page(page); 1228 } 1229 1230 if (bprm->security) 1231 security_bprm_free(bprm); 1232 1233 out_mm: 1234 if (bprm->mm) 1235 mmdrop(bprm->mm); 1236 1237 out_file: 1238 if (bprm->file) { 1239 allow_write_access(bprm->file); 1240 fput(bprm->file); 1241 } 1242 1243 out_kfree: 1244 kfree(bprm); 1245 1246 out_ret: 1247 return retval; 1248 } 1249 1250 int set_binfmt(struct linux_binfmt *new) 1251 { 1252 struct linux_binfmt *old = current->binfmt; 1253 1254 if (new) { 1255 if (!try_module_get(new->module)) 1256 return -1; 1257 } 1258 current->binfmt = new; 1259 if (old) 1260 module_put(old->module); 1261 return 0; 1262 } 1263 1264 EXPORT_SYMBOL(set_binfmt); 1265 1266 #define CORENAME_MAX_SIZE 64 1267 1268 /* format_corename will inspect the pattern parameter, and output a 1269 * name into corename, which must have space for at least 1270 * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. 1271 */ 1272 static void format_corename(char *corename, const char *pattern, long signr) 1273 { 1274 const char *pat_ptr = pattern; 1275 char *out_ptr = corename; 1276 char *const out_end = corename + CORENAME_MAX_SIZE; 1277 int rc; 1278 int pid_in_pattern = 0; 1279 1280 /* Repeat as long as we have more pattern to process and more output 1281 space */ 1282 while (*pat_ptr) { 1283 if (*pat_ptr != '%') { 1284 if (out_ptr == out_end) 1285 goto out; 1286 *out_ptr++ = *pat_ptr++; 1287 } else { 1288 switch (*++pat_ptr) { 1289 case 0: 1290 goto out; 1291 /* Double percent, output one percent */ 1292 case '%': 1293 if (out_ptr == out_end) 1294 goto out; 1295 *out_ptr++ = '%'; 1296 break; 1297 /* pid */ 1298 case 'p': 1299 pid_in_pattern = 1; 1300 rc = snprintf(out_ptr, out_end - out_ptr, 1301 "%d", current->tgid); 1302 if (rc > out_end - out_ptr) 1303 goto out; 1304 out_ptr += rc; 1305 break; 1306 /* uid */ 1307 case 'u': 1308 rc = snprintf(out_ptr, out_end - out_ptr, 1309 "%d", current->uid); 1310 if (rc > out_end - out_ptr) 1311 goto out; 1312 out_ptr += rc; 1313 break; 1314 /* gid */ 1315 case 'g': 1316 rc = snprintf(out_ptr, out_end - out_ptr, 1317 "%d", current->gid); 1318 if (rc > out_end - out_ptr) 1319 goto out; 1320 out_ptr += rc; 1321 break; 1322 /* signal that caused the coredump */ 1323 case 's': 1324 rc = snprintf(out_ptr, out_end - out_ptr, 1325 "%ld", signr); 1326 if (rc > out_end - out_ptr) 1327 goto out; 1328 out_ptr += rc; 1329 break; 1330 /* UNIX time of coredump */ 1331 case 't': { 1332 struct timeval tv; 1333 do_gettimeofday(&tv); 1334 rc = snprintf(out_ptr, out_end - out_ptr, 1335 "%lu", tv.tv_sec); 1336 if (rc > out_end - out_ptr) 1337 goto out; 1338 out_ptr += rc; 1339 break; 1340 } 1341 /* hostname */ 1342 case 'h': 1343 down_read(&uts_sem); 1344 rc = snprintf(out_ptr, out_end - out_ptr, 1345 "%s", system_utsname.nodename); 1346 up_read(&uts_sem); 1347 if (rc > out_end - out_ptr) 1348 goto out; 1349 out_ptr += rc; 1350 break; 1351 /* executable */ 1352 case 'e': 1353 rc = snprintf(out_ptr, out_end - out_ptr, 1354 "%s", current->comm); 1355 if (rc > out_end - out_ptr) 1356 goto out; 1357 out_ptr += rc; 1358 break; 1359 default: 1360 break; 1361 } 1362 ++pat_ptr; 1363 } 1364 } 1365 /* Backward compatibility with core_uses_pid: 1366 * 1367 * If core_pattern does not include a %p (as is the default) 1368 * and core_uses_pid is set, then .%pid will be appended to 1369 * the filename */ 1370 if (!pid_in_pattern 1371 && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) { 1372 rc = snprintf(out_ptr, out_end - out_ptr, 1373 ".%d", current->tgid); 1374 if (rc > out_end - out_ptr) 1375 goto out; 1376 out_ptr += rc; 1377 } 1378 out: 1379 *out_ptr = 0; 1380 } 1381 1382 static void zap_threads (struct mm_struct *mm) 1383 { 1384 struct task_struct *g, *p; 1385 struct task_struct *tsk = current; 1386 struct completion *vfork_done = tsk->vfork_done; 1387 int traced = 0; 1388 1389 /* 1390 * Make sure nobody is waiting for us to release the VM, 1391 * otherwise we can deadlock when we wait on each other 1392 */ 1393 if (vfork_done) { 1394 tsk->vfork_done = NULL; 1395 complete(vfork_done); 1396 } 1397 1398 read_lock(&tasklist_lock); 1399 do_each_thread(g,p) 1400 if (mm == p->mm && p != tsk) { 1401 force_sig_specific(SIGKILL, p); 1402 mm->core_waiters++; 1403 if (unlikely(p->ptrace) && 1404 unlikely(p->parent->mm == mm)) 1405 traced = 1; 1406 } 1407 while_each_thread(g,p); 1408 1409 read_unlock(&tasklist_lock); 1410 1411 if (unlikely(traced)) { 1412 /* 1413 * We are zapping a thread and the thread it ptraces. 1414 * If the tracee went into a ptrace stop for exit tracing, 1415 * we could deadlock since the tracer is waiting for this 1416 * coredump to finish. Detach them so they can both die. 1417 */ 1418 write_lock_irq(&tasklist_lock); 1419 do_each_thread(g,p) { 1420 if (mm == p->mm && p != tsk && 1421 p->ptrace && p->parent->mm == mm) { 1422 __ptrace_detach(p, 0); 1423 } 1424 } while_each_thread(g,p); 1425 write_unlock_irq(&tasklist_lock); 1426 } 1427 } 1428 1429 static void coredump_wait(struct mm_struct *mm) 1430 { 1431 DECLARE_COMPLETION(startup_done); 1432 int core_waiters; 1433 1434 mm->core_startup_done = &startup_done; 1435 1436 zap_threads(mm); 1437 core_waiters = mm->core_waiters; 1438 up_write(&mm->mmap_sem); 1439 1440 if (core_waiters) 1441 wait_for_completion(&startup_done); 1442 BUG_ON(mm->core_waiters); 1443 } 1444 1445 int do_coredump(long signr, int exit_code, struct pt_regs * regs) 1446 { 1447 char corename[CORENAME_MAX_SIZE + 1]; 1448 struct mm_struct *mm = current->mm; 1449 struct linux_binfmt * binfmt; 1450 struct inode * inode; 1451 struct file * file; 1452 int retval = 0; 1453 int fsuid = current->fsuid; 1454 int flag = 0; 1455 1456 binfmt = current->binfmt; 1457 if (!binfmt || !binfmt->core_dump) 1458 goto fail; 1459 down_write(&mm->mmap_sem); 1460 if (!mm->dumpable) { 1461 up_write(&mm->mmap_sem); 1462 goto fail; 1463 } 1464 1465 /* 1466 * We cannot trust fsuid as being the "true" uid of the 1467 * process nor do we know its entire history. We only know it 1468 * was tainted so we dump it as root in mode 2. 1469 */ 1470 if (mm->dumpable == 2) { /* Setuid core dump mode */ 1471 flag = O_EXCL; /* Stop rewrite attacks */ 1472 current->fsuid = 0; /* Dump root private */ 1473 } 1474 mm->dumpable = 0; 1475 1476 retval = -EAGAIN; 1477 spin_lock_irq(¤t->sighand->siglock); 1478 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { 1479 current->signal->flags = SIGNAL_GROUP_EXIT; 1480 current->signal->group_exit_code = exit_code; 1481 current->signal->group_stop_count = 0; 1482 retval = 0; 1483 } 1484 spin_unlock_irq(¤t->sighand->siglock); 1485 if (retval) { 1486 up_write(&mm->mmap_sem); 1487 goto fail; 1488 } 1489 1490 init_completion(&mm->core_done); 1491 coredump_wait(mm); 1492 1493 /* 1494 * Clear any false indication of pending signals that might 1495 * be seen by the filesystem code called to write the core file. 1496 */ 1497 clear_thread_flag(TIF_SIGPENDING); 1498 1499 if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump) 1500 goto fail_unlock; 1501 1502 /* 1503 * lock_kernel() because format_corename() is controlled by sysctl, which 1504 * uses lock_kernel() 1505 */ 1506 lock_kernel(); 1507 format_corename(corename, core_pattern, signr); 1508 unlock_kernel(); 1509 file = filp_open(corename, O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, 0600); 1510 if (IS_ERR(file)) 1511 goto fail_unlock; 1512 inode = file->f_dentry->d_inode; 1513 if (inode->i_nlink > 1) 1514 goto close_fail; /* multiple links - don't dump */ 1515 if (d_unhashed(file->f_dentry)) 1516 goto close_fail; 1517 1518 if (!S_ISREG(inode->i_mode)) 1519 goto close_fail; 1520 if (!file->f_op) 1521 goto close_fail; 1522 if (!file->f_op->write) 1523 goto close_fail; 1524 if (do_truncate(file->f_dentry, 0, 0, file) != 0) 1525 goto close_fail; 1526 1527 retval = binfmt->core_dump(signr, regs, file); 1528 1529 if (retval) 1530 current->signal->group_exit_code |= 0x80; 1531 close_fail: 1532 filp_close(file, NULL); 1533 fail_unlock: 1534 current->fsuid = fsuid; 1535 complete_all(&mm->core_done); 1536 fail: 1537 return retval; 1538 } 1539