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/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> 41 #include <linux/pid_namespace.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/tsacct_kern.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[128] = "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_zalloc(vm_area_cachep, GFP_KERNEL); 409 if (!mpnt) 410 return -ENOMEM; 411 412 down_write(&mm->mmap_sem); 413 { 414 mpnt->vm_mm = mm; 415 #ifdef CONFIG_STACK_GROWSUP 416 mpnt->vm_start = stack_base; 417 mpnt->vm_end = stack_base + arg_size; 418 #else 419 mpnt->vm_end = stack_top; 420 mpnt->vm_start = mpnt->vm_end - arg_size; 421 #endif 422 /* Adjust stack execute permissions; explicitly enable 423 * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X 424 * and leave alone (arch default) otherwise. */ 425 if (unlikely(executable_stack == EXSTACK_ENABLE_X)) 426 mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC; 427 else if (executable_stack == EXSTACK_DISABLE_X) 428 mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC; 429 else 430 mpnt->vm_flags = VM_STACK_FLAGS; 431 mpnt->vm_flags |= mm->def_flags; 432 mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7]; 433 if ((ret = insert_vm_struct(mm, mpnt))) { 434 up_write(&mm->mmap_sem); 435 kmem_cache_free(vm_area_cachep, mpnt); 436 return ret; 437 } 438 mm->stack_vm = mm->total_vm = vma_pages(mpnt); 439 } 440 441 for (i = 0 ; i < MAX_ARG_PAGES ; i++) { 442 struct page *page = bprm->page[i]; 443 if (page) { 444 bprm->page[i] = NULL; 445 install_arg_page(mpnt, page, stack_base); 446 } 447 stack_base += PAGE_SIZE; 448 } 449 up_write(&mm->mmap_sem); 450 451 return 0; 452 } 453 454 EXPORT_SYMBOL(setup_arg_pages); 455 456 #define free_arg_pages(bprm) do { } while (0) 457 458 #else 459 460 static inline void free_arg_pages(struct linux_binprm *bprm) 461 { 462 int i; 463 464 for (i = 0; i < MAX_ARG_PAGES; i++) { 465 if (bprm->page[i]) 466 __free_page(bprm->page[i]); 467 bprm->page[i] = NULL; 468 } 469 } 470 471 #endif /* CONFIG_MMU */ 472 473 struct file *open_exec(const char *name) 474 { 475 struct nameidata nd; 476 int err; 477 struct file *file; 478 479 err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, FMODE_READ|FMODE_EXEC); 480 file = ERR_PTR(err); 481 482 if (!err) { 483 struct inode *inode = nd.dentry->d_inode; 484 file = ERR_PTR(-EACCES); 485 if (!(nd.mnt->mnt_flags & MNT_NOEXEC) && 486 S_ISREG(inode->i_mode)) { 487 int err = vfs_permission(&nd, MAY_EXEC); 488 file = ERR_PTR(err); 489 if (!err) { 490 file = nameidata_to_filp(&nd, O_RDONLY); 491 if (!IS_ERR(file)) { 492 err = deny_write_access(file); 493 if (err) { 494 fput(file); 495 file = ERR_PTR(err); 496 } 497 } 498 out: 499 return file; 500 } 501 } 502 release_open_intent(&nd); 503 path_release(&nd); 504 } 505 goto out; 506 } 507 508 EXPORT_SYMBOL(open_exec); 509 510 int kernel_read(struct file *file, unsigned long offset, 511 char *addr, unsigned long count) 512 { 513 mm_segment_t old_fs; 514 loff_t pos = offset; 515 int result; 516 517 old_fs = get_fs(); 518 set_fs(get_ds()); 519 /* The cast to a user pointer is valid due to the set_fs() */ 520 result = vfs_read(file, (void __user *)addr, count, &pos); 521 set_fs(old_fs); 522 return result; 523 } 524 525 EXPORT_SYMBOL(kernel_read); 526 527 static int exec_mmap(struct mm_struct *mm) 528 { 529 struct task_struct *tsk; 530 struct mm_struct * old_mm, *active_mm; 531 532 /* Notify parent that we're no longer interested in the old VM */ 533 tsk = current; 534 old_mm = current->mm; 535 mm_release(tsk, old_mm); 536 537 if (old_mm) { 538 /* 539 * Make sure that if there is a core dump in progress 540 * for the old mm, we get out and die instead of going 541 * through with the exec. We must hold mmap_sem around 542 * checking core_waiters and changing tsk->mm. The 543 * core-inducing thread will increment core_waiters for 544 * each thread whose ->mm == old_mm. 545 */ 546 down_read(&old_mm->mmap_sem); 547 if (unlikely(old_mm->core_waiters)) { 548 up_read(&old_mm->mmap_sem); 549 return -EINTR; 550 } 551 } 552 task_lock(tsk); 553 active_mm = tsk->active_mm; 554 tsk->mm = mm; 555 tsk->active_mm = mm; 556 activate_mm(active_mm, mm); 557 task_unlock(tsk); 558 arch_pick_mmap_layout(mm); 559 if (old_mm) { 560 up_read(&old_mm->mmap_sem); 561 BUG_ON(active_mm != old_mm); 562 mmput(old_mm); 563 return 0; 564 } 565 mmdrop(active_mm); 566 return 0; 567 } 568 569 /* 570 * This function makes sure the current process has its own signal table, 571 * so that flush_signal_handlers can later reset the handlers without 572 * disturbing other processes. (Other processes might share the signal 573 * table via the CLONE_SIGHAND option to clone().) 574 */ 575 static int de_thread(struct task_struct *tsk) 576 { 577 struct signal_struct *sig = tsk->signal; 578 struct sighand_struct *newsighand, *oldsighand = tsk->sighand; 579 spinlock_t *lock = &oldsighand->siglock; 580 struct task_struct *leader = NULL; 581 int count; 582 583 /* 584 * If we don't share sighandlers, then we aren't sharing anything 585 * and we can just re-use it all. 586 */ 587 if (atomic_read(&oldsighand->count) <= 1) { 588 BUG_ON(atomic_read(&sig->count) != 1); 589 exit_itimers(sig); 590 return 0; 591 } 592 593 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL); 594 if (!newsighand) 595 return -ENOMEM; 596 597 if (thread_group_empty(tsk)) 598 goto no_thread_group; 599 600 /* 601 * Kill all other threads in the thread group. 602 * We must hold tasklist_lock to call zap_other_threads. 603 */ 604 read_lock(&tasklist_lock); 605 spin_lock_irq(lock); 606 if (sig->flags & SIGNAL_GROUP_EXIT) { 607 /* 608 * Another group action in progress, just 609 * return so that the signal is processed. 610 */ 611 spin_unlock_irq(lock); 612 read_unlock(&tasklist_lock); 613 kmem_cache_free(sighand_cachep, newsighand); 614 return -EAGAIN; 615 } 616 617 /* 618 * child_reaper ignores SIGKILL, change it now. 619 * Reparenting needs write_lock on tasklist_lock, 620 * so it is safe to do it under read_lock. 621 */ 622 if (unlikely(tsk->group_leader == child_reaper(tsk))) 623 tsk->nsproxy->pid_ns->child_reaper = tsk; 624 625 zap_other_threads(tsk); 626 read_unlock(&tasklist_lock); 627 628 /* 629 * Account for the thread group leader hanging around: 630 */ 631 count = 1; 632 if (!thread_group_leader(tsk)) { 633 count = 2; 634 /* 635 * The SIGALRM timer survives the exec, but needs to point 636 * at us as the new group leader now. We have a race with 637 * a timer firing now getting the old leader, so we need to 638 * synchronize with any firing (by calling del_timer_sync) 639 * before we can safely let the old group leader die. 640 */ 641 sig->tsk = tsk; 642 spin_unlock_irq(lock); 643 if (hrtimer_cancel(&sig->real_timer)) 644 hrtimer_restart(&sig->real_timer); 645 spin_lock_irq(lock); 646 } 647 while (atomic_read(&sig->count) > count) { 648 sig->group_exit_task = tsk; 649 sig->notify_count = count; 650 __set_current_state(TASK_UNINTERRUPTIBLE); 651 spin_unlock_irq(lock); 652 schedule(); 653 spin_lock_irq(lock); 654 } 655 sig->group_exit_task = NULL; 656 sig->notify_count = 0; 657 spin_unlock_irq(lock); 658 659 /* 660 * At this point all other threads have exited, all we have to 661 * do is to wait for the thread group leader to become inactive, 662 * and to assume its PID: 663 */ 664 if (!thread_group_leader(tsk)) { 665 /* 666 * Wait for the thread group leader to be a zombie. 667 * It should already be zombie at this point, most 668 * of the time. 669 */ 670 leader = tsk->group_leader; 671 while (leader->exit_state != EXIT_ZOMBIE) 672 yield(); 673 674 /* 675 * The only record we have of the real-time age of a 676 * process, regardless of execs it's done, is start_time. 677 * All the past CPU time is accumulated in signal_struct 678 * from sister threads now dead. But in this non-leader 679 * exec, nothing survives from the original leader thread, 680 * whose birth marks the true age of this process now. 681 * When we take on its identity by switching to its PID, we 682 * also take its birthdate (always earlier than our own). 683 */ 684 tsk->start_time = leader->start_time; 685 686 write_lock_irq(&tasklist_lock); 687 688 BUG_ON(leader->tgid != tsk->tgid); 689 BUG_ON(tsk->pid == tsk->tgid); 690 /* 691 * An exec() starts a new thread group with the 692 * TGID of the previous thread group. Rehash the 693 * two threads with a switched PID, and release 694 * the former thread group leader: 695 */ 696 697 /* Become a process group leader with the old leader's pid. 698 * The old leader becomes a thread of the this thread group. 699 * Note: The old leader also uses this pid until release_task 700 * is called. Odd but simple and correct. 701 */ 702 detach_pid(tsk, PIDTYPE_PID); 703 tsk->pid = leader->pid; 704 attach_pid(tsk, PIDTYPE_PID, tsk->pid); 705 transfer_pid(leader, tsk, PIDTYPE_PGID); 706 transfer_pid(leader, tsk, PIDTYPE_SID); 707 list_replace_rcu(&leader->tasks, &tsk->tasks); 708 709 tsk->group_leader = tsk; 710 leader->group_leader = tsk; 711 712 tsk->exit_signal = SIGCHLD; 713 714 BUG_ON(leader->exit_state != EXIT_ZOMBIE); 715 leader->exit_state = EXIT_DEAD; 716 717 write_unlock_irq(&tasklist_lock); 718 } 719 720 /* 721 * There may be one thread left which is just exiting, 722 * but it's safe to stop telling the group to kill themselves. 723 */ 724 sig->flags = 0; 725 726 no_thread_group: 727 exit_itimers(sig); 728 if (leader) 729 release_task(leader); 730 731 BUG_ON(atomic_read(&sig->count) != 1); 732 733 if (atomic_read(&oldsighand->count) == 1) { 734 /* 735 * Now that we nuked the rest of the thread group, 736 * it turns out we are not sharing sighand any more either. 737 * So we can just keep it. 738 */ 739 kmem_cache_free(sighand_cachep, newsighand); 740 } else { 741 /* 742 * Move our state over to newsighand and switch it in. 743 */ 744 atomic_set(&newsighand->count, 1); 745 memcpy(newsighand->action, oldsighand->action, 746 sizeof(newsighand->action)); 747 748 write_lock_irq(&tasklist_lock); 749 spin_lock(&oldsighand->siglock); 750 spin_lock_nested(&newsighand->siglock, SINGLE_DEPTH_NESTING); 751 752 rcu_assign_pointer(tsk->sighand, newsighand); 753 recalc_sigpending(); 754 755 spin_unlock(&newsighand->siglock); 756 spin_unlock(&oldsighand->siglock); 757 write_unlock_irq(&tasklist_lock); 758 759 if (atomic_dec_and_test(&oldsighand->count)) 760 kmem_cache_free(sighand_cachep, oldsighand); 761 } 762 763 BUG_ON(!thread_group_leader(tsk)); 764 return 0; 765 } 766 767 /* 768 * These functions flushes out all traces of the currently running executable 769 * so that a new one can be started 770 */ 771 772 static void flush_old_files(struct files_struct * files) 773 { 774 long j = -1; 775 struct fdtable *fdt; 776 777 spin_lock(&files->file_lock); 778 for (;;) { 779 unsigned long set, i; 780 781 j++; 782 i = j * __NFDBITS; 783 fdt = files_fdtable(files); 784 if (i >= fdt->max_fds) 785 break; 786 set = fdt->close_on_exec->fds_bits[j]; 787 if (!set) 788 continue; 789 fdt->close_on_exec->fds_bits[j] = 0; 790 spin_unlock(&files->file_lock); 791 for ( ; set ; i++,set >>= 1) { 792 if (set & 1) { 793 sys_close(i); 794 } 795 } 796 spin_lock(&files->file_lock); 797 798 } 799 spin_unlock(&files->file_lock); 800 } 801 802 void get_task_comm(char *buf, struct task_struct *tsk) 803 { 804 /* buf must be at least sizeof(tsk->comm) in size */ 805 task_lock(tsk); 806 strncpy(buf, tsk->comm, sizeof(tsk->comm)); 807 task_unlock(tsk); 808 } 809 810 void set_task_comm(struct task_struct *tsk, char *buf) 811 { 812 task_lock(tsk); 813 strlcpy(tsk->comm, buf, sizeof(tsk->comm)); 814 task_unlock(tsk); 815 } 816 817 int flush_old_exec(struct linux_binprm * bprm) 818 { 819 char * name; 820 int i, ch, retval; 821 struct files_struct *files; 822 char tcomm[sizeof(current->comm)]; 823 824 /* 825 * Make sure we have a private signal table and that 826 * we are unassociated from the previous thread group. 827 */ 828 retval = de_thread(current); 829 if (retval) 830 goto out; 831 832 /* 833 * Make sure we have private file handles. Ask the 834 * fork helper to do the work for us and the exit 835 * helper to do the cleanup of the old one. 836 */ 837 files = current->files; /* refcounted so safe to hold */ 838 retval = unshare_files(); 839 if (retval) 840 goto out; 841 /* 842 * Release all of the old mmap stuff 843 */ 844 retval = exec_mmap(bprm->mm); 845 if (retval) 846 goto mmap_failed; 847 848 bprm->mm = NULL; /* We're using it now */ 849 850 /* This is the point of no return */ 851 put_files_struct(files); 852 853 current->sas_ss_sp = current->sas_ss_size = 0; 854 855 if (current->euid == current->uid && current->egid == current->gid) 856 current->mm->dumpable = 1; 857 else 858 current->mm->dumpable = suid_dumpable; 859 860 name = bprm->filename; 861 862 /* Copies the binary name from after last slash */ 863 for (i=0; (ch = *(name++)) != '\0';) { 864 if (ch == '/') 865 i = 0; /* overwrite what we wrote */ 866 else 867 if (i < (sizeof(tcomm) - 1)) 868 tcomm[i++] = ch; 869 } 870 tcomm[i] = '\0'; 871 set_task_comm(current, tcomm); 872 873 current->flags &= ~PF_RANDOMIZE; 874 flush_thread(); 875 876 /* Set the new mm task size. We have to do that late because it may 877 * depend on TIF_32BIT which is only updated in flush_thread() on 878 * some architectures like powerpc 879 */ 880 current->mm->task_size = TASK_SIZE; 881 882 if (bprm->e_uid != current->euid || bprm->e_gid != current->egid || 883 file_permission(bprm->file, MAY_READ) || 884 (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) { 885 suid_keys(current); 886 current->mm->dumpable = suid_dumpable; 887 } 888 889 /* An exec changes our domain. We are no longer part of the thread 890 group */ 891 892 current->self_exec_id++; 893 894 flush_signal_handlers(current, 0); 895 flush_old_files(current->files); 896 897 return 0; 898 899 mmap_failed: 900 reset_files_struct(current, files); 901 out: 902 return retval; 903 } 904 905 EXPORT_SYMBOL(flush_old_exec); 906 907 /* 908 * Fill the binprm structure from the inode. 909 * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes 910 */ 911 int prepare_binprm(struct linux_binprm *bprm) 912 { 913 int mode; 914 struct inode * inode = bprm->file->f_path.dentry->d_inode; 915 int retval; 916 917 mode = inode->i_mode; 918 if (bprm->file->f_op == NULL) 919 return -EACCES; 920 921 bprm->e_uid = current->euid; 922 bprm->e_gid = current->egid; 923 924 if(!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) { 925 /* Set-uid? */ 926 if (mode & S_ISUID) { 927 current->personality &= ~PER_CLEAR_ON_SETID; 928 bprm->e_uid = inode->i_uid; 929 } 930 931 /* Set-gid? */ 932 /* 933 * If setgid is set but no group execute bit then this 934 * is a candidate for mandatory locking, not a setgid 935 * executable. 936 */ 937 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) { 938 current->personality &= ~PER_CLEAR_ON_SETID; 939 bprm->e_gid = inode->i_gid; 940 } 941 } 942 943 /* fill in binprm security blob */ 944 retval = security_bprm_set(bprm); 945 if (retval) 946 return retval; 947 948 memset(bprm->buf,0,BINPRM_BUF_SIZE); 949 return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE); 950 } 951 952 EXPORT_SYMBOL(prepare_binprm); 953 954 static int unsafe_exec(struct task_struct *p) 955 { 956 int unsafe = 0; 957 if (p->ptrace & PT_PTRACED) { 958 if (p->ptrace & PT_PTRACE_CAP) 959 unsafe |= LSM_UNSAFE_PTRACE_CAP; 960 else 961 unsafe |= LSM_UNSAFE_PTRACE; 962 } 963 if (atomic_read(&p->fs->count) > 1 || 964 atomic_read(&p->files->count) > 1 || 965 atomic_read(&p->sighand->count) > 1) 966 unsafe |= LSM_UNSAFE_SHARE; 967 968 return unsafe; 969 } 970 971 void compute_creds(struct linux_binprm *bprm) 972 { 973 int unsafe; 974 975 if (bprm->e_uid != current->uid) 976 suid_keys(current); 977 exec_keys(current); 978 979 task_lock(current); 980 unsafe = unsafe_exec(current); 981 security_bprm_apply_creds(bprm, unsafe); 982 task_unlock(current); 983 security_bprm_post_apply_creds(bprm); 984 } 985 EXPORT_SYMBOL(compute_creds); 986 987 /* 988 * Arguments are '\0' separated strings found at the location bprm->p 989 * points to; chop off the first by relocating brpm->p to right after 990 * the first '\0' encountered. 991 */ 992 void remove_arg_zero(struct linux_binprm *bprm) 993 { 994 if (bprm->argc) { 995 char ch; 996 997 do { 998 unsigned long offset; 999 unsigned long index; 1000 char *kaddr; 1001 struct page *page; 1002 1003 offset = bprm->p & ~PAGE_MASK; 1004 index = bprm->p >> PAGE_SHIFT; 1005 1006 page = bprm->page[index]; 1007 kaddr = kmap_atomic(page, KM_USER0); 1008 1009 /* run through page until we reach end or find NUL */ 1010 do { 1011 ch = *(kaddr + offset); 1012 1013 /* discard that character... */ 1014 bprm->p++; 1015 offset++; 1016 } while (offset < PAGE_SIZE && ch != '\0'); 1017 1018 kunmap_atomic(kaddr, KM_USER0); 1019 1020 /* free the old page */ 1021 if (offset == PAGE_SIZE) { 1022 __free_page(page); 1023 bprm->page[index] = NULL; 1024 } 1025 } while (ch != '\0'); 1026 1027 bprm->argc--; 1028 } 1029 } 1030 EXPORT_SYMBOL(remove_arg_zero); 1031 1032 /* 1033 * cycle the list of binary formats handler, until one recognizes the image 1034 */ 1035 int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs) 1036 { 1037 int try,retval; 1038 struct linux_binfmt *fmt; 1039 #ifdef __alpha__ 1040 /* handle /sbin/loader.. */ 1041 { 1042 struct exec * eh = (struct exec *) bprm->buf; 1043 1044 if (!bprm->loader && eh->fh.f_magic == 0x183 && 1045 (eh->fh.f_flags & 0x3000) == 0x3000) 1046 { 1047 struct file * file; 1048 unsigned long loader; 1049 1050 allow_write_access(bprm->file); 1051 fput(bprm->file); 1052 bprm->file = NULL; 1053 1054 loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); 1055 1056 file = open_exec("/sbin/loader"); 1057 retval = PTR_ERR(file); 1058 if (IS_ERR(file)) 1059 return retval; 1060 1061 /* Remember if the application is TASO. */ 1062 bprm->sh_bang = eh->ah.entry < 0x100000000UL; 1063 1064 bprm->file = file; 1065 bprm->loader = loader; 1066 retval = prepare_binprm(bprm); 1067 if (retval<0) 1068 return retval; 1069 /* should call search_binary_handler recursively here, 1070 but it does not matter */ 1071 } 1072 } 1073 #endif 1074 retval = security_bprm_check(bprm); 1075 if (retval) 1076 return retval; 1077 1078 /* kernel module loader fixup */ 1079 /* so we don't try to load run modprobe in kernel space. */ 1080 set_fs(USER_DS); 1081 1082 retval = audit_bprm(bprm); 1083 if (retval) 1084 return retval; 1085 1086 retval = -ENOENT; 1087 for (try=0; try<2; try++) { 1088 read_lock(&binfmt_lock); 1089 for (fmt = formats ; fmt ; fmt = fmt->next) { 1090 int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary; 1091 if (!fn) 1092 continue; 1093 if (!try_module_get(fmt->module)) 1094 continue; 1095 read_unlock(&binfmt_lock); 1096 retval = fn(bprm, regs); 1097 if (retval >= 0) { 1098 put_binfmt(fmt); 1099 allow_write_access(bprm->file); 1100 if (bprm->file) 1101 fput(bprm->file); 1102 bprm->file = NULL; 1103 current->did_exec = 1; 1104 proc_exec_connector(current); 1105 return retval; 1106 } 1107 read_lock(&binfmt_lock); 1108 put_binfmt(fmt); 1109 if (retval != -ENOEXEC || bprm->mm == NULL) 1110 break; 1111 if (!bprm->file) { 1112 read_unlock(&binfmt_lock); 1113 return retval; 1114 } 1115 } 1116 read_unlock(&binfmt_lock); 1117 if (retval != -ENOEXEC || bprm->mm == NULL) { 1118 break; 1119 #ifdef CONFIG_KMOD 1120 }else{ 1121 #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) 1122 if (printable(bprm->buf[0]) && 1123 printable(bprm->buf[1]) && 1124 printable(bprm->buf[2]) && 1125 printable(bprm->buf[3])) 1126 break; /* -ENOEXEC */ 1127 request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2])); 1128 #endif 1129 } 1130 } 1131 return retval; 1132 } 1133 1134 EXPORT_SYMBOL(search_binary_handler); 1135 1136 /* 1137 * sys_execve() executes a new program. 1138 */ 1139 int do_execve(char * filename, 1140 char __user *__user *argv, 1141 char __user *__user *envp, 1142 struct pt_regs * regs) 1143 { 1144 struct linux_binprm *bprm; 1145 struct file *file; 1146 int retval; 1147 int i; 1148 1149 retval = -ENOMEM; 1150 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); 1151 if (!bprm) 1152 goto out_ret; 1153 1154 file = open_exec(filename); 1155 retval = PTR_ERR(file); 1156 if (IS_ERR(file)) 1157 goto out_kfree; 1158 1159 sched_exec(); 1160 1161 bprm->p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *); 1162 1163 bprm->file = file; 1164 bprm->filename = filename; 1165 bprm->interp = filename; 1166 bprm->mm = mm_alloc(); 1167 retval = -ENOMEM; 1168 if (!bprm->mm) 1169 goto out_file; 1170 1171 retval = init_new_context(current, bprm->mm); 1172 if (retval < 0) 1173 goto out_mm; 1174 1175 bprm->argc = count(argv, bprm->p / sizeof(void *)); 1176 if ((retval = bprm->argc) < 0) 1177 goto out_mm; 1178 1179 bprm->envc = count(envp, bprm->p / sizeof(void *)); 1180 if ((retval = bprm->envc) < 0) 1181 goto out_mm; 1182 1183 retval = security_bprm_alloc(bprm); 1184 if (retval) 1185 goto out; 1186 1187 retval = prepare_binprm(bprm); 1188 if (retval < 0) 1189 goto out; 1190 1191 retval = copy_strings_kernel(1, &bprm->filename, bprm); 1192 if (retval < 0) 1193 goto out; 1194 1195 bprm->exec = bprm->p; 1196 retval = copy_strings(bprm->envc, envp, bprm); 1197 if (retval < 0) 1198 goto out; 1199 1200 retval = copy_strings(bprm->argc, argv, bprm); 1201 if (retval < 0) 1202 goto out; 1203 1204 retval = search_binary_handler(bprm,regs); 1205 if (retval >= 0) { 1206 free_arg_pages(bprm); 1207 1208 /* execve success */ 1209 security_bprm_free(bprm); 1210 acct_update_integrals(current); 1211 kfree(bprm); 1212 return retval; 1213 } 1214 1215 out: 1216 /* Something went wrong, return the inode and free the argument pages*/ 1217 for (i = 0 ; i < MAX_ARG_PAGES ; i++) { 1218 struct page * page = bprm->page[i]; 1219 if (page) 1220 __free_page(page); 1221 } 1222 1223 if (bprm->security) 1224 security_bprm_free(bprm); 1225 1226 out_mm: 1227 if (bprm->mm) 1228 mmdrop(bprm->mm); 1229 1230 out_file: 1231 if (bprm->file) { 1232 allow_write_access(bprm->file); 1233 fput(bprm->file); 1234 } 1235 1236 out_kfree: 1237 kfree(bprm); 1238 1239 out_ret: 1240 return retval; 1241 } 1242 1243 int set_binfmt(struct linux_binfmt *new) 1244 { 1245 struct linux_binfmt *old = current->binfmt; 1246 1247 if (new) { 1248 if (!try_module_get(new->module)) 1249 return -1; 1250 } 1251 current->binfmt = new; 1252 if (old) 1253 module_put(old->module); 1254 return 0; 1255 } 1256 1257 EXPORT_SYMBOL(set_binfmt); 1258 1259 #define CORENAME_MAX_SIZE 64 1260 1261 /* format_corename will inspect the pattern parameter, and output a 1262 * name into corename, which must have space for at least 1263 * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator. 1264 */ 1265 static int format_corename(char *corename, const char *pattern, long signr) 1266 { 1267 const char *pat_ptr = pattern; 1268 char *out_ptr = corename; 1269 char *const out_end = corename + CORENAME_MAX_SIZE; 1270 int rc; 1271 int pid_in_pattern = 0; 1272 int ispipe = 0; 1273 1274 if (*pattern == '|') 1275 ispipe = 1; 1276 1277 /* Repeat as long as we have more pattern to process and more output 1278 space */ 1279 while (*pat_ptr) { 1280 if (*pat_ptr != '%') { 1281 if (out_ptr == out_end) 1282 goto out; 1283 *out_ptr++ = *pat_ptr++; 1284 } else { 1285 switch (*++pat_ptr) { 1286 case 0: 1287 goto out; 1288 /* Double percent, output one percent */ 1289 case '%': 1290 if (out_ptr == out_end) 1291 goto out; 1292 *out_ptr++ = '%'; 1293 break; 1294 /* pid */ 1295 case 'p': 1296 pid_in_pattern = 1; 1297 rc = snprintf(out_ptr, out_end - out_ptr, 1298 "%d", current->tgid); 1299 if (rc > out_end - out_ptr) 1300 goto out; 1301 out_ptr += rc; 1302 break; 1303 /* uid */ 1304 case 'u': 1305 rc = snprintf(out_ptr, out_end - out_ptr, 1306 "%d", current->uid); 1307 if (rc > out_end - out_ptr) 1308 goto out; 1309 out_ptr += rc; 1310 break; 1311 /* gid */ 1312 case 'g': 1313 rc = snprintf(out_ptr, out_end - out_ptr, 1314 "%d", current->gid); 1315 if (rc > out_end - out_ptr) 1316 goto out; 1317 out_ptr += rc; 1318 break; 1319 /* signal that caused the coredump */ 1320 case 's': 1321 rc = snprintf(out_ptr, out_end - out_ptr, 1322 "%ld", signr); 1323 if (rc > out_end - out_ptr) 1324 goto out; 1325 out_ptr += rc; 1326 break; 1327 /* UNIX time of coredump */ 1328 case 't': { 1329 struct timeval tv; 1330 do_gettimeofday(&tv); 1331 rc = snprintf(out_ptr, out_end - out_ptr, 1332 "%lu", tv.tv_sec); 1333 if (rc > out_end - out_ptr) 1334 goto out; 1335 out_ptr += rc; 1336 break; 1337 } 1338 /* hostname */ 1339 case 'h': 1340 down_read(&uts_sem); 1341 rc = snprintf(out_ptr, out_end - out_ptr, 1342 "%s", utsname()->nodename); 1343 up_read(&uts_sem); 1344 if (rc > out_end - out_ptr) 1345 goto out; 1346 out_ptr += rc; 1347 break; 1348 /* executable */ 1349 case 'e': 1350 rc = snprintf(out_ptr, out_end - out_ptr, 1351 "%s", current->comm); 1352 if (rc > out_end - out_ptr) 1353 goto out; 1354 out_ptr += rc; 1355 break; 1356 default: 1357 break; 1358 } 1359 ++pat_ptr; 1360 } 1361 } 1362 /* Backward compatibility with core_uses_pid: 1363 * 1364 * If core_pattern does not include a %p (as is the default) 1365 * and core_uses_pid is set, then .%pid will be appended to 1366 * the filename. Do not do this for piped commands. */ 1367 if (!ispipe && !pid_in_pattern 1368 && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) { 1369 rc = snprintf(out_ptr, out_end - out_ptr, 1370 ".%d", current->tgid); 1371 if (rc > out_end - out_ptr) 1372 goto out; 1373 out_ptr += rc; 1374 } 1375 out: 1376 *out_ptr = 0; 1377 return ispipe; 1378 } 1379 1380 static void zap_process(struct task_struct *start) 1381 { 1382 struct task_struct *t; 1383 1384 start->signal->flags = SIGNAL_GROUP_EXIT; 1385 start->signal->group_stop_count = 0; 1386 1387 t = start; 1388 do { 1389 if (t != current && t->mm) { 1390 t->mm->core_waiters++; 1391 sigaddset(&t->pending.signal, SIGKILL); 1392 signal_wake_up(t, 1); 1393 } 1394 } while ((t = next_thread(t)) != start); 1395 } 1396 1397 static inline int zap_threads(struct task_struct *tsk, struct mm_struct *mm, 1398 int exit_code) 1399 { 1400 struct task_struct *g, *p; 1401 unsigned long flags; 1402 int err = -EAGAIN; 1403 1404 spin_lock_irq(&tsk->sighand->siglock); 1405 if (!(tsk->signal->flags & SIGNAL_GROUP_EXIT)) { 1406 tsk->signal->group_exit_code = exit_code; 1407 zap_process(tsk); 1408 err = 0; 1409 } 1410 spin_unlock_irq(&tsk->sighand->siglock); 1411 if (err) 1412 return err; 1413 1414 if (atomic_read(&mm->mm_users) == mm->core_waiters + 1) 1415 goto done; 1416 1417 rcu_read_lock(); 1418 for_each_process(g) { 1419 if (g == tsk->group_leader) 1420 continue; 1421 1422 p = g; 1423 do { 1424 if (p->mm) { 1425 if (p->mm == mm) { 1426 /* 1427 * p->sighand can't disappear, but 1428 * may be changed by de_thread() 1429 */ 1430 lock_task_sighand(p, &flags); 1431 zap_process(p); 1432 unlock_task_sighand(p, &flags); 1433 } 1434 break; 1435 } 1436 } while ((p = next_thread(p)) != g); 1437 } 1438 rcu_read_unlock(); 1439 done: 1440 return mm->core_waiters; 1441 } 1442 1443 static int coredump_wait(int exit_code) 1444 { 1445 struct task_struct *tsk = current; 1446 struct mm_struct *mm = tsk->mm; 1447 struct completion startup_done; 1448 struct completion *vfork_done; 1449 int core_waiters; 1450 1451 init_completion(&mm->core_done); 1452 init_completion(&startup_done); 1453 mm->core_startup_done = &startup_done; 1454 1455 core_waiters = zap_threads(tsk, mm, exit_code); 1456 up_write(&mm->mmap_sem); 1457 1458 if (unlikely(core_waiters < 0)) 1459 goto fail; 1460 1461 /* 1462 * Make sure nobody is waiting for us to release the VM, 1463 * otherwise we can deadlock when we wait on each other 1464 */ 1465 vfork_done = tsk->vfork_done; 1466 if (vfork_done) { 1467 tsk->vfork_done = NULL; 1468 complete(vfork_done); 1469 } 1470 1471 if (core_waiters) 1472 wait_for_completion(&startup_done); 1473 fail: 1474 BUG_ON(mm->core_waiters); 1475 return core_waiters; 1476 } 1477 1478 int do_coredump(long signr, int exit_code, struct pt_regs * regs) 1479 { 1480 char corename[CORENAME_MAX_SIZE + 1]; 1481 struct mm_struct *mm = current->mm; 1482 struct linux_binfmt * binfmt; 1483 struct inode * inode; 1484 struct file * file; 1485 int retval = 0; 1486 int fsuid = current->fsuid; 1487 int flag = 0; 1488 int ispipe = 0; 1489 1490 binfmt = current->binfmt; 1491 if (!binfmt || !binfmt->core_dump) 1492 goto fail; 1493 down_write(&mm->mmap_sem); 1494 if (!mm->dumpable) { 1495 up_write(&mm->mmap_sem); 1496 goto fail; 1497 } 1498 1499 /* 1500 * We cannot trust fsuid as being the "true" uid of the 1501 * process nor do we know its entire history. We only know it 1502 * was tainted so we dump it as root in mode 2. 1503 */ 1504 if (mm->dumpable == 2) { /* Setuid core dump mode */ 1505 flag = O_EXCL; /* Stop rewrite attacks */ 1506 current->fsuid = 0; /* Dump root private */ 1507 } 1508 mm->dumpable = 0; 1509 1510 retval = coredump_wait(exit_code); 1511 if (retval < 0) 1512 goto fail; 1513 1514 /* 1515 * Clear any false indication of pending signals that might 1516 * be seen by the filesystem code called to write the core file. 1517 */ 1518 clear_thread_flag(TIF_SIGPENDING); 1519 1520 if (current->signal->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump) 1521 goto fail_unlock; 1522 1523 /* 1524 * lock_kernel() because format_corename() is controlled by sysctl, which 1525 * uses lock_kernel() 1526 */ 1527 lock_kernel(); 1528 ispipe = format_corename(corename, core_pattern, signr); 1529 unlock_kernel(); 1530 if (ispipe) { 1531 /* SIGPIPE can happen, but it's just never processed */ 1532 if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) { 1533 printk(KERN_INFO "Core dump to %s pipe failed\n", 1534 corename); 1535 goto fail_unlock; 1536 } 1537 } else 1538 file = filp_open(corename, 1539 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag, 1540 0600); 1541 if (IS_ERR(file)) 1542 goto fail_unlock; 1543 inode = file->f_path.dentry->d_inode; 1544 if (inode->i_nlink > 1) 1545 goto close_fail; /* multiple links - don't dump */ 1546 if (!ispipe && d_unhashed(file->f_path.dentry)) 1547 goto close_fail; 1548 1549 /* AK: actually i see no reason to not allow this for named pipes etc., 1550 but keep the previous behaviour for now. */ 1551 if (!ispipe && !S_ISREG(inode->i_mode)) 1552 goto close_fail; 1553 if (!file->f_op) 1554 goto close_fail; 1555 if (!file->f_op->write) 1556 goto close_fail; 1557 if (!ispipe && do_truncate(file->f_path.dentry, 0, 0, file) != 0) 1558 goto close_fail; 1559 1560 retval = binfmt->core_dump(signr, regs, file); 1561 1562 if (retval) 1563 current->signal->group_exit_code |= 0x80; 1564 close_fail: 1565 filp_close(file, NULL); 1566 fail_unlock: 1567 current->fsuid = fsuid; 1568 complete_all(&mm->core_done); 1569 fail: 1570 return retval; 1571 } 1572