4 * Copyright (C) 1991, 1992 Linus Torvalds
8 * #!-checking implemented by tytso.
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.
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.
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
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/personality.h>
38 #include <linux/binfmts.h>
39 #include <linux/swap.h>
40 #include <linux/utsname.h>
41 #include <linux/module.h>
42 #include <linux/namei.h>
43 #include <linux/proc_fs.h>
44 #include <linux/ptrace.h>
45 #include <linux/mount.h>
46 #include <linux/security.h>
47 #include <linux/syscalls.h>
48 #include <linux/rmap.h>
50 #include <asm/uaccess.h>
51 #include <asm/pgalloc.h>
52 #include <asm/mmu_context.h>
55 #include <linux/kmod.h>
59 char core_pattern[65] = "core";
60 /* The maximal length of core_pattern is also specified in sysctl.c */
62 static struct linux_binfmt *formats;
63 static rwlock_t binfmt_lock = RW_LOCK_UNLOCKED;
65 int register_binfmt(struct linux_binfmt * fmt)
67 struct linux_binfmt ** tmp = &formats;
73 write_lock(&binfmt_lock);
76 write_unlock(&binfmt_lock);
83 write_unlock(&binfmt_lock);
87 EXPORT_SYMBOL(register_binfmt);
89 int unregister_binfmt(struct linux_binfmt * fmt)
91 struct linux_binfmt ** tmp = &formats;
93 write_lock(&binfmt_lock);
97 write_unlock(&binfmt_lock);
102 write_unlock(&binfmt_lock);
106 EXPORT_SYMBOL(unregister_binfmt);
108 static inline void put_binfmt(struct linux_binfmt * fmt)
110 module_put(fmt->module);
114 * Note that a shared library must be both readable and executable due to
117 * Also note that we take the address to load from from the file itself.
119 asmlinkage long sys_uselib(const char __user * library)
125 nd.intent.open.flags = FMODE_READ;
126 error = __user_walk(library, LOOKUP_FOLLOW|LOOKUP_OPEN, &nd);
131 if (!S_ISREG(nd.dentry->d_inode->i_mode))
134 error = permission(nd.dentry->d_inode, MAY_READ | MAY_EXEC, &nd);
138 file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
139 error = PTR_ERR(file);
145 struct linux_binfmt * fmt;
147 read_lock(&binfmt_lock);
148 for (fmt = formats ; fmt ; fmt = fmt->next) {
149 if (!fmt->load_shlib)
151 if (!try_module_get(fmt->module))
153 read_unlock(&binfmt_lock);
154 error = fmt->load_shlib(file);
155 read_lock(&binfmt_lock);
157 if (error != -ENOEXEC)
160 read_unlock(&binfmt_lock);
171 * count() counts the number of strings in array ARGV.
173 static int count(char __user * __user * argv, int max)
181 if (get_user(p, argv))
194 * 'copy_strings()' copies argument/environment strings from user
195 * memory to free pages in kernel mem. These are in a format ready
196 * to be put directly into the top of new user memory.
198 int copy_strings(int argc,char __user * __user * argv, struct linux_binprm *bprm)
200 struct page *kmapped_page = NULL;
209 if (get_user(str, argv+argc) ||
210 !(len = strnlen_user(str, bprm->p))) {
221 /* XXX: add architecture specific overflow check here. */
226 int offset, bytes_to_copy;
229 offset = pos % PAGE_SIZE;
231 page = bprm->page[i];
234 page = alloc_page(GFP_HIGHUSER);
235 bprm->page[i] = page;
243 if (page != kmapped_page) {
245 kunmap(kmapped_page);
247 kaddr = kmap(kmapped_page);
250 memset(kaddr, 0, offset);
251 bytes_to_copy = PAGE_SIZE - offset;
252 if (bytes_to_copy > len) {
255 memset(kaddr+offset+len, 0,
256 PAGE_SIZE-offset-len);
258 err = copy_from_user(kaddr+offset, str, bytes_to_copy);
264 pos += bytes_to_copy;
265 str += bytes_to_copy;
266 len -= bytes_to_copy;
272 kunmap(kmapped_page);
277 * Like copy_strings, but get argv and its values from kernel memory.
279 int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm)
282 mm_segment_t oldfs = get_fs();
284 r = copy_strings(argc, (char __user * __user *)argv, bprm);
289 EXPORT_SYMBOL(copy_strings_kernel);
293 * This routine is used to map in a page into an address space: needed by
294 * execve() for the initial stack and environment pages.
296 * vma->vm_mm->mmap_sem is held for writing.
298 void install_arg_page(struct vm_area_struct *vma,
299 struct page *page, unsigned long address)
301 struct mm_struct *mm = vma->vm_mm;
306 if (unlikely(anon_vma_prepare(vma)))
309 flush_dcache_page(page);
310 pgd = pgd_offset(mm, address);
312 spin_lock(&mm->page_table_lock);
313 pmd = pmd_alloc(mm, pgd, address);
316 pte = pte_alloc_map(mm, pmd, address);
319 if (!pte_none(*pte)) {
324 lru_cache_add_active(page);
325 set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(
326 page, vma->vm_page_prot))));
327 page_add_anon_rmap(page, vma, address);
329 spin_unlock(&mm->page_table_lock);
331 /* no need for flush_tlb */
334 spin_unlock(&mm->page_table_lock);
337 force_sig(SIGKILL, current);
340 int setup_arg_pages(struct linux_binprm *bprm, int executable_stack)
342 unsigned long stack_base;
343 struct vm_area_struct *mpnt;
344 struct mm_struct *mm = current->mm;
348 #ifdef CONFIG_STACK_GROWSUP
349 /* Move the argument and environment strings to the bottom of the
355 /* Start by shifting all the pages down */
357 for (j = 0; j < MAX_ARG_PAGES; j++) {
358 struct page *page = bprm->page[j];
361 bprm->page[i++] = page;
364 /* Now move them within their pages */
365 offset = bprm->p % PAGE_SIZE;
366 to = kmap(bprm->page[0]);
367 for (j = 1; j < i; j++) {
368 memmove(to, to + offset, PAGE_SIZE - offset);
369 from = kmap(bprm->page[j]);
370 memcpy(to + PAGE_SIZE - offset, from, offset);
371 kunmap(bprm->page[j - 1]);
374 memmove(to, to + offset, PAGE_SIZE - offset);
375 kunmap(bprm->page[j - 1]);
377 /* Adjust bprm->p to point to the end of the strings. */
378 bprm->p = PAGE_SIZE * i - offset;
380 /* Limit stack size to 1GB */
381 stack_base = current->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);
386 mm->arg_start = stack_base;
387 arg_size = i << PAGE_SHIFT;
389 /* zero pages that were copied above */
390 while (i < MAX_ARG_PAGES)
391 bprm->page[i++] = NULL;
393 #ifdef __HAVE_ARCH_ALIGN_STACK
394 stack_base = arch_align_stack(STACK_TOP - MAX_ARG_PAGES*PAGE_SIZE);
395 stack_base = PAGE_ALIGN(stack_base);
397 stack_base = STACK_TOP - MAX_ARG_PAGES * PAGE_SIZE;
399 mm->arg_start = bprm->p + stack_base;
400 arg_size = STACK_TOP - (PAGE_MASK & (unsigned long) mm->arg_start);
403 bprm->p += stack_base;
405 bprm->loader += stack_base;
406 bprm->exec += stack_base;
408 mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
412 if (security_vm_enough_memory(arg_size >> PAGE_SHIFT)) {
413 kmem_cache_free(vm_area_cachep, mpnt);
417 memset(mpnt, 0, sizeof(*mpnt));
419 down_write(&mm->mmap_sem);
422 #ifdef CONFIG_STACK_GROWSUP
423 mpnt->vm_start = stack_base;
424 mpnt->vm_end = PAGE_MASK &
425 (PAGE_SIZE - 1 + (unsigned long) bprm->p);
427 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
428 mpnt->vm_end = STACK_TOP;
430 /* Adjust stack execute permissions; explicitly enable
431 * for EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X
432 * and leave alone (arch default) otherwise. */
433 if (unlikely(executable_stack == EXSTACK_ENABLE_X))
434 mpnt->vm_flags = VM_STACK_FLAGS | VM_EXEC;
435 else if (executable_stack == EXSTACK_DISABLE_X)
436 mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
438 mpnt->vm_flags = VM_STACK_FLAGS;
439 mpnt->vm_page_prot = protection_map[mpnt->vm_flags & 0x7];
440 insert_vm_struct(mm, mpnt);
441 mm->total_vm = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
444 for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
445 struct page *page = bprm->page[i];
447 bprm->page[i] = NULL;
448 install_arg_page(mpnt, page, stack_base);
450 stack_base += PAGE_SIZE;
452 up_write(&mm->mmap_sem);
457 EXPORT_SYMBOL(setup_arg_pages);
459 #define free_arg_pages(bprm) do { } while (0)
463 static inline void free_arg_pages(struct linux_binprm *bprm)
467 for (i = 0; i < MAX_ARG_PAGES; i++) {
469 __free_page(bprm->page[i]);
470 bprm->page[i] = NULL;
474 #endif /* CONFIG_MMU */
476 struct file *open_exec(const char *name)
482 nd.intent.open.flags = FMODE_READ;
483 err = path_lookup(name, LOOKUP_FOLLOW|LOOKUP_OPEN, &nd);
487 struct inode *inode = nd.dentry->d_inode;
488 file = ERR_PTR(-EACCES);
489 if (!(nd.mnt->mnt_flags & MNT_NOEXEC) &&
490 S_ISREG(inode->i_mode)) {
491 int err = permission(inode, MAY_EXEC, &nd);
492 if (!err && !(inode->i_mode & 0111))
496 file = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
498 err = deny_write_access(file);
513 EXPORT_SYMBOL(open_exec);
515 int kernel_read(struct file *file, unsigned long offset,
516 char *addr, unsigned long count)
524 /* The cast to a user pointer is valid due to the set_fs() */
525 result = vfs_read(file, (void __user *)addr, count, &pos);
530 EXPORT_SYMBOL(kernel_read);
532 static int exec_mmap(struct mm_struct *mm)
534 struct task_struct *tsk;
535 struct mm_struct * old_mm, *active_mm;
537 /* Add it to the list of mm's */
538 spin_lock(&mmlist_lock);
539 list_add(&mm->mmlist, &init_mm.mmlist);
541 spin_unlock(&mmlist_lock);
543 /* Notify parent that we're no longer interested in the old VM */
545 old_mm = current->mm;
546 mm_release(tsk, old_mm);
549 active_mm = tsk->active_mm;
552 activate_mm(active_mm, mm);
555 if (active_mm != old_mm) BUG();
564 * This function makes sure the current process has its own signal table,
565 * so that flush_signal_handlers can later reset the handlers without
566 * disturbing other processes. (Other processes might share the signal
567 * table via the CLONE_SIGHAND option to clone().)
569 static inline int de_thread(struct task_struct *tsk)
571 struct signal_struct *newsig, *oldsig = tsk->signal;
572 struct sighand_struct *newsighand, *oldsighand = tsk->sighand;
573 spinlock_t *lock = &oldsighand->siglock;
577 * If we don't share sighandlers, then we aren't sharing anything
578 * and we can just re-use it all.
580 if (atomic_read(&oldsighand->count) <= 1)
583 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
587 spin_lock_init(&newsighand->siglock);
588 atomic_set(&newsighand->count, 1);
589 memcpy(newsighand->action, oldsighand->action, sizeof(newsighand->action));
592 * See if we need to allocate a new signal structure
595 if (atomic_read(&oldsig->count) > 1) {
596 newsig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
598 kmem_cache_free(sighand_cachep, newsighand);
601 atomic_set(&newsig->count, 1);
602 newsig->group_exit = 0;
603 newsig->group_exit_code = 0;
604 newsig->group_exit_task = NULL;
605 newsig->group_stop_count = 0;
606 newsig->curr_target = NULL;
607 init_sigpending(&newsig->shared_pending);
608 INIT_LIST_HEAD(&newsig->posix_timers);
610 newsig->tty = oldsig->tty;
611 newsig->pgrp = oldsig->pgrp;
612 newsig->session = oldsig->session;
613 newsig->leader = oldsig->leader;
614 newsig->tty_old_pgrp = oldsig->tty_old_pgrp;
617 if (thread_group_empty(current))
618 goto no_thread_group;
621 * Kill all other threads in the thread group.
622 * We must hold tasklist_lock to call zap_other_threads.
624 read_lock(&tasklist_lock);
626 if (oldsig->group_exit) {
628 * Another group action in progress, just
629 * return so that the signal is processed.
631 spin_unlock_irq(lock);
632 read_unlock(&tasklist_lock);
633 kmem_cache_free(sighand_cachep, newsighand);
635 kmem_cache_free(signal_cachep, newsig);
638 oldsig->group_exit = 1;
639 zap_other_threads(current);
640 read_unlock(&tasklist_lock);
643 * Account for the thread group leader hanging around:
646 if (current->pid == current->tgid)
648 while (atomic_read(&oldsig->count) > count) {
649 oldsig->group_exit_task = current;
650 oldsig->notify_count = count;
651 __set_current_state(TASK_UNINTERRUPTIBLE);
652 spin_unlock_irq(lock);
656 spin_unlock_irq(lock);
659 * At this point all other threads have exited, all we have to
660 * do is to wait for the thread group leader to become inactive,
661 * and to assume its PID:
663 if (current->pid != current->tgid) {
664 struct task_struct *leader = current->group_leader, *parent;
665 struct dentry *proc_dentry1, *proc_dentry2;
666 unsigned long state, ptrace;
669 * Wait for the thread group leader to be a zombie.
670 * It should already be zombie at this point, most
673 while (leader->state != TASK_ZOMBIE)
676 spin_lock(&leader->proc_lock);
677 spin_lock(¤t->proc_lock);
678 proc_dentry1 = proc_pid_unhash(current);
679 proc_dentry2 = proc_pid_unhash(leader);
680 write_lock_irq(&tasklist_lock);
682 if (leader->tgid != current->tgid)
684 if (current->pid == current->tgid)
687 * An exec() starts a new thread group with the
688 * TGID of the previous thread group. Rehash the
689 * two threads with a switched PID, and release
690 * the former thread group leader:
692 ptrace = leader->ptrace;
693 parent = leader->parent;
695 ptrace_unlink(current);
696 ptrace_unlink(leader);
697 remove_parent(current);
698 remove_parent(leader);
700 switch_exec_pids(leader, current);
702 current->parent = current->real_parent = leader->real_parent;
703 leader->parent = leader->real_parent = child_reaper;
704 current->group_leader = current;
705 leader->group_leader = leader;
707 add_parent(current, current->parent);
708 add_parent(leader, leader->parent);
710 current->ptrace = ptrace;
711 __ptrace_link(current, parent);
714 list_del(¤t->tasks);
715 list_add_tail(¤t->tasks, &init_task.tasks);
716 current->exit_signal = SIGCHLD;
717 state = leader->state;
719 write_unlock_irq(&tasklist_lock);
720 spin_unlock(&leader->proc_lock);
721 spin_unlock(¤t->proc_lock);
722 proc_pid_flush(proc_dentry1);
723 proc_pid_flush(proc_dentry2);
725 if (state != TASK_ZOMBIE)
727 release_task(leader);
732 write_lock_irq(&tasklist_lock);
733 spin_lock(&oldsighand->siglock);
734 spin_lock(&newsighand->siglock);
736 if (current == oldsig->curr_target)
737 oldsig->curr_target = next_thread(current);
739 current->signal = newsig;
740 current->sighand = newsighand;
741 init_sigpending(¤t->pending);
744 spin_unlock(&newsighand->siglock);
745 spin_unlock(&oldsighand->siglock);
746 write_unlock_irq(&tasklist_lock);
748 if (newsig && atomic_dec_and_test(&oldsig->count))
749 kmem_cache_free(signal_cachep, oldsig);
751 if (atomic_dec_and_test(&oldsighand->count))
752 kmem_cache_free(sighand_cachep, oldsighand);
754 if (!thread_group_empty(current))
756 if (current->tgid != current->pid)
762 * These functions flushes out all traces of the currently running executable
763 * so that a new one can be started
766 static inline void flush_old_files(struct files_struct * files)
770 spin_lock(&files->file_lock);
772 unsigned long set, i;
776 if (i >= files->max_fds || i >= files->max_fdset)
778 set = files->close_on_exec->fds_bits[j];
781 files->close_on_exec->fds_bits[j] = 0;
782 spin_unlock(&files->file_lock);
783 for ( ; set ; i++,set >>= 1) {
788 spin_lock(&files->file_lock);
791 spin_unlock(&files->file_lock);
794 int flush_old_exec(struct linux_binprm * bprm)
798 struct files_struct *files;
801 * Make sure we have a private signal table and that
802 * we are unassociated from the previous thread group.
804 retval = de_thread(current);
809 * Make sure we have private file handles. Ask the
810 * fork helper to do the work for us and the exit
811 * helper to do the cleanup of the old one.
813 files = current->files; /* refcounted so safe to hold */
814 retval = unshare_files();
818 * Release all of the old mmap stuff
820 retval = exec_mmap(bprm->mm);
824 bprm->mm = NULL; /* We're using it now */
826 /* This is the point of no return */
828 put_files_struct(files);
830 current->sas_ss_sp = current->sas_ss_size = 0;
832 if (current->euid == current->uid && current->egid == current->gid)
833 current->mm->dumpable = 1;
834 name = bprm->filename;
835 for (i=0; (ch = *(name++)) != '\0';) {
840 current->comm[i++] = ch;
842 current->comm[i] = '\0';
844 current->flags &= ~PF_RELOCEXEC;
847 if (bprm->e_uid != current->euid || bprm->e_gid != current->egid ||
848 permission(bprm->file->f_dentry->d_inode,MAY_READ, NULL))
849 current->mm->dumpable = 0;
851 /* An exec changes our domain. We are no longer part of the thread
854 current->self_exec_id++;
856 flush_signal_handlers(current, 0);
857 flush_old_files(current->files);
862 put_files_struct(current->files);
863 current->files = files;
868 EXPORT_SYMBOL(flush_old_exec);
871 * Fill the binprm structure from the inode.
872 * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
874 int prepare_binprm(struct linux_binprm *bprm)
877 struct inode * inode = bprm->file->f_dentry->d_inode;
880 mode = inode->i_mode;
882 * Check execute perms again - if the caller has CAP_DAC_OVERRIDE,
883 * vfs_permission lets a non-executable through
885 if (!(mode & 0111)) /* with at least _one_ execute bit set */
887 if (bprm->file->f_op == NULL)
890 bprm->e_uid = current->euid;
891 bprm->e_gid = current->egid;
893 if(!(bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)) {
895 if (mode & S_ISUID) {
896 bprm->e_uid = inode->i_uid;
898 /* reset personality */
899 current->personality = PER_LINUX;
905 * If setgid is set but no group execute bit then this
906 * is a candidate for mandatory locking, not a setgid
909 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
910 bprm->e_gid = inode->i_gid;
912 /* reset personality */
913 current->personality = PER_LINUX;
918 /* fill in binprm security blob */
919 retval = security_bprm_set(bprm);
923 memset(bprm->buf,0,BINPRM_BUF_SIZE);
924 return kernel_read(bprm->file,0,bprm->buf,BINPRM_BUF_SIZE);
927 EXPORT_SYMBOL(prepare_binprm);
929 static inline int unsafe_exec(struct task_struct *p)
932 if (p->ptrace & PT_PTRACED) {
933 if (p->ptrace & PT_PTRACE_CAP)
934 unsafe |= LSM_UNSAFE_PTRACE_CAP;
936 unsafe |= LSM_UNSAFE_PTRACE;
938 if (atomic_read(&p->fs->count) > 1 ||
939 atomic_read(&p->files->count) > 1 ||
940 atomic_read(&p->sighand->count) > 1)
941 unsafe |= LSM_UNSAFE_SHARE;
946 void compute_creds(struct linux_binprm *bprm)
950 unsafe = unsafe_exec(current);
951 security_bprm_apply_creds(bprm, unsafe);
952 task_unlock(current);
955 EXPORT_SYMBOL(compute_creds);
957 void remove_arg_zero(struct linux_binprm *bprm)
960 unsigned long offset;
964 offset = bprm->p % PAGE_SIZE;
967 while (bprm->p++, *(kaddr+offset++)) {
968 if (offset != PAGE_SIZE)
971 kunmap_atomic(kaddr, KM_USER0);
973 page = bprm->page[bprm->p/PAGE_SIZE];
974 kaddr = kmap_atomic(page, KM_USER0);
976 kunmap_atomic(kaddr, KM_USER0);
981 EXPORT_SYMBOL(remove_arg_zero);
984 * cycle the list of binary formats handler, until one recognizes the image
986 int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
989 struct linux_binfmt *fmt;
991 /* handle /sbin/loader.. */
993 struct exec * eh = (struct exec *) bprm->buf;
995 if (!bprm->loader && eh->fh.f_magic == 0x183 &&
996 (eh->fh.f_flags & 0x3000) == 0x3000)
999 unsigned long loader;
1001 allow_write_access(bprm->file);
1005 loader = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
1007 file = open_exec("/sbin/loader");
1008 retval = PTR_ERR(file);
1012 /* Remember if the application is TASO. */
1013 bprm->sh_bang = eh->ah.entry < 0x100000000UL;
1016 bprm->loader = loader;
1017 retval = prepare_binprm(bprm);
1020 /* should call search_binary_handler recursively here,
1021 but it does not matter */
1025 retval = security_bprm_check(bprm);
1029 /* kernel module loader fixup */
1030 /* so we don't try to load run modprobe in kernel space. */
1032 for (try=0; try<2; try++) {
1033 read_lock(&binfmt_lock);
1034 for (fmt = formats ; fmt ; fmt = fmt->next) {
1035 int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
1038 if (!try_module_get(fmt->module))
1040 read_unlock(&binfmt_lock);
1041 retval = fn(bprm, regs);
1044 allow_write_access(bprm->file);
1048 current->did_exec = 1;
1051 read_lock(&binfmt_lock);
1053 if (retval != -ENOEXEC || bprm->mm == NULL)
1056 read_unlock(&binfmt_lock);
1060 read_unlock(&binfmt_lock);
1061 if (retval != -ENOEXEC || bprm->mm == NULL) {
1065 #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
1066 if (printable(bprm->buf[0]) &&
1067 printable(bprm->buf[1]) &&
1068 printable(bprm->buf[2]) &&
1069 printable(bprm->buf[3]))
1070 break; /* -ENOEXEC */
1071 request_module("binfmt-%04x", *(unsigned short *)(&bprm->buf[2]));
1078 EXPORT_SYMBOL(search_binary_handler);
1081 * sys_execve() executes a new program.
1083 int do_execve(char * filename,
1084 char __user *__user *argv,
1085 char __user *__user *envp,
1086 struct pt_regs * regs)
1088 struct linux_binprm bprm;
1093 sched_balance_exec();
1095 file = open_exec(filename);
1097 retval = PTR_ERR(file);
1101 bprm.p = PAGE_SIZE*MAX_ARG_PAGES-sizeof(void *);
1102 memset(bprm.page, 0, MAX_ARG_PAGES*sizeof(bprm.page[0]));
1105 bprm.filename = filename;
1106 bprm.interp = filename;
1110 bprm.security = NULL;
1111 bprm.mm = mm_alloc();
1116 retval = init_new_context(current, bprm.mm);
1120 bprm.argc = count(argv, bprm.p / sizeof(void *));
1121 if ((retval = bprm.argc) < 0)
1124 bprm.envc = count(envp, bprm.p / sizeof(void *));
1125 if ((retval = bprm.envc) < 0)
1128 retval = security_bprm_alloc(&bprm);
1132 retval = prepare_binprm(&bprm);
1136 retval = copy_strings_kernel(1, &bprm.filename, &bprm);
1141 retval = copy_strings(bprm.envc, envp, &bprm);
1145 retval = copy_strings(bprm.argc, argv, &bprm);
1149 retval = search_binary_handler(&bprm,regs);
1151 free_arg_pages(&bprm);
1153 /* execve success */
1154 security_bprm_free(&bprm);
1159 /* Something went wrong, return the inode and free the argument pages*/
1160 for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
1161 struct page * page = bprm.page[i];
1167 security_bprm_free(&bprm);
1175 allow_write_access(bprm.file);
1181 EXPORT_SYMBOL(do_execve);
1183 int set_binfmt(struct linux_binfmt *new)
1185 struct linux_binfmt *old = current->binfmt;
1188 if (!try_module_get(new->module))
1191 current->binfmt = new;
1193 module_put(old->module);
1197 EXPORT_SYMBOL(set_binfmt);
1199 #define CORENAME_MAX_SIZE 64
1201 /* format_corename will inspect the pattern parameter, and output a
1202 * name into corename, which must have space for at least
1203 * CORENAME_MAX_SIZE bytes plus one byte for the zero terminator.
1205 void format_corename(char *corename, const char *pattern, long signr)
1207 const char *pat_ptr = pattern;
1208 char *out_ptr = corename;
1209 char *const out_end = corename + CORENAME_MAX_SIZE;
1211 int pid_in_pattern = 0;
1213 /* Repeat as long as we have more pattern to process and more output
1216 if (*pat_ptr != '%') {
1217 if (out_ptr == out_end)
1219 *out_ptr++ = *pat_ptr++;
1221 switch (*++pat_ptr) {
1224 /* Double percent, output one percent */
1226 if (out_ptr == out_end)
1233 rc = snprintf(out_ptr, out_end - out_ptr,
1234 "%d", current->tgid);
1235 if (rc > out_end - out_ptr)
1241 rc = snprintf(out_ptr, out_end - out_ptr,
1242 "%d", current->uid);
1243 if (rc > out_end - out_ptr)
1249 rc = snprintf(out_ptr, out_end - out_ptr,
1250 "%d", current->gid);
1251 if (rc > out_end - out_ptr)
1255 /* signal that caused the coredump */
1257 rc = snprintf(out_ptr, out_end - out_ptr,
1259 if (rc > out_end - out_ptr)
1263 /* UNIX time of coredump */
1266 do_gettimeofday(&tv);
1267 rc = snprintf(out_ptr, out_end - out_ptr,
1269 if (rc > out_end - out_ptr)
1276 down_read(&uts_sem);
1277 rc = snprintf(out_ptr, out_end - out_ptr,
1278 "%s", system_utsname.nodename);
1280 if (rc > out_end - out_ptr)
1286 rc = snprintf(out_ptr, out_end - out_ptr,
1287 "%s", current->comm);
1288 if (rc > out_end - out_ptr)
1298 /* Backward compatibility with core_uses_pid:
1300 * If core_pattern does not include a %p (as is the default)
1301 * and core_uses_pid is set, then .%pid will be appended to
1304 && (core_uses_pid || atomic_read(¤t->mm->mm_users) != 1)) {
1305 rc = snprintf(out_ptr, out_end - out_ptr,
1306 ".%d", current->tgid);
1307 if (rc > out_end - out_ptr)
1315 static void zap_threads (struct mm_struct *mm)
1317 struct task_struct *g, *p;
1318 struct task_struct *tsk = current;
1319 struct completion *vfork_done = tsk->vfork_done;
1322 * Make sure nobody is waiting for us to release the VM,
1323 * otherwise we can deadlock when we wait on each other
1326 tsk->vfork_done = NULL;
1327 complete(vfork_done);
1330 read_lock(&tasklist_lock);
1332 if (mm == p->mm && p != tsk) {
1333 force_sig_specific(SIGKILL, p);
1336 while_each_thread(g,p);
1338 read_unlock(&tasklist_lock);
1341 static void coredump_wait(struct mm_struct *mm)
1343 DECLARE_COMPLETION(startup_done);
1345 mm->core_waiters++; /* let other threads block */
1346 mm->core_startup_done = &startup_done;
1348 /* give other threads a chance to run: */
1352 if (--mm->core_waiters) {
1353 up_write(&mm->mmap_sem);
1354 wait_for_completion(&startup_done);
1356 up_write(&mm->mmap_sem);
1357 BUG_ON(mm->core_waiters);
1360 int do_coredump(long signr, int exit_code, struct pt_regs * regs)
1362 char corename[CORENAME_MAX_SIZE + 1];
1363 struct mm_struct *mm = current->mm;
1364 struct linux_binfmt * binfmt;
1365 struct inode * inode;
1370 binfmt = current->binfmt;
1371 if (!binfmt || !binfmt->core_dump)
1373 down_write(&mm->mmap_sem);
1374 if (!mm->dumpable) {
1375 up_write(&mm->mmap_sem);
1379 init_completion(&mm->core_done);
1380 current->signal->group_exit = 1;
1381 current->signal->group_exit_code = exit_code;
1384 if (current->rlim[RLIMIT_CORE].rlim_cur < binfmt->min_coredump)
1387 format_corename(corename, core_pattern, signr);
1388 file = filp_open(corename, O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE, 0600);
1391 inode = file->f_dentry->d_inode;
1392 if (inode->i_nlink > 1)
1393 goto close_fail; /* multiple links - don't dump */
1394 if (d_unhashed(file->f_dentry))
1397 if (!S_ISREG(inode->i_mode))
1401 if (!file->f_op->write)
1403 if (do_truncate(file->f_dentry, 0) != 0)
1406 retval = binfmt->core_dump(signr, regs, file);
1408 current->signal->group_exit_code |= 0x80;
1410 filp_close(file, NULL);
1412 complete_all(&mm->core_done);