diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-04-05 19:41:22 -0400 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2009-04-05 19:41:22 -0400 |
commit | 9efe21cb82b5dbe3b0b2ae4de4eccc64ecb94e95 (patch) | |
tree | 7ff8833745d2f268f897f6fa4a27263b4a572245 /kernel/exit.c | |
parent | de18836e447c2dc30120c0919b8db8ddc0401cc4 (diff) | |
parent | 0221c81b1b8eb0cbb6b30a0ced52ead32d2b4e4c (diff) |
Merge branch 'linus' into irq/threaded
Conflicts:
include/linux/irq.h
kernel/irq/handle.c
Diffstat (limited to 'kernel/exit.c')
-rw-r--r-- | kernel/exit.c | 245 |
1 files changed, 69 insertions, 176 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index ca0b3488c4a9..789b8862fe3b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c | |||
@@ -46,6 +46,7 @@ | |||
46 | #include <linux/blkdev.h> | 46 | #include <linux/blkdev.h> |
47 | #include <linux/task_io_accounting_ops.h> | 47 | #include <linux/task_io_accounting_ops.h> |
48 | #include <linux/tracehook.h> | 48 | #include <linux/tracehook.h> |
49 | #include <linux/fs_struct.h> | ||
49 | #include <linux/init_task.h> | 50 | #include <linux/init_task.h> |
50 | #include <trace/sched.h> | 51 | #include <trace/sched.h> |
51 | 52 | ||
@@ -61,11 +62,6 @@ DEFINE_TRACE(sched_process_wait); | |||
61 | 62 | ||
62 | static void exit_mm(struct task_struct * tsk); | 63 | static void exit_mm(struct task_struct * tsk); |
63 | 64 | ||
64 | static inline int task_detached(struct task_struct *p) | ||
65 | { | ||
66 | return p->exit_signal == -1; | ||
67 | } | ||
68 | |||
69 | static void __unhash_process(struct task_struct *p) | 65 | static void __unhash_process(struct task_struct *p) |
70 | { | 66 | { |
71 | nr_threads--; | 67 | nr_threads--; |
@@ -362,16 +358,12 @@ static void reparent_to_kthreadd(void) | |||
362 | void __set_special_pids(struct pid *pid) | 358 | void __set_special_pids(struct pid *pid) |
363 | { | 359 | { |
364 | struct task_struct *curr = current->group_leader; | 360 | struct task_struct *curr = current->group_leader; |
365 | pid_t nr = pid_nr(pid); | ||
366 | 361 | ||
367 | if (task_session(curr) != pid) { | 362 | if (task_session(curr) != pid) |
368 | change_pid(curr, PIDTYPE_SID, pid); | 363 | change_pid(curr, PIDTYPE_SID, pid); |
369 | set_task_session(curr, nr); | 364 | |
370 | } | 365 | if (task_pgrp(curr) != pid) |
371 | if (task_pgrp(curr) != pid) { | ||
372 | change_pid(curr, PIDTYPE_PGID, pid); | 366 | change_pid(curr, PIDTYPE_PGID, pid); |
373 | set_task_pgrp(curr, nr); | ||
374 | } | ||
375 | } | 367 | } |
376 | 368 | ||
377 | static void set_special_pids(struct pid *pid) | 369 | static void set_special_pids(struct pid *pid) |
@@ -429,7 +421,6 @@ EXPORT_SYMBOL(disallow_signal); | |||
429 | void daemonize(const char *name, ...) | 421 | void daemonize(const char *name, ...) |
430 | { | 422 | { |
431 | va_list args; | 423 | va_list args; |
432 | struct fs_struct *fs; | ||
433 | sigset_t blocked; | 424 | sigset_t blocked; |
434 | 425 | ||
435 | va_start(args, name); | 426 | va_start(args, name); |
@@ -462,11 +453,7 @@ void daemonize(const char *name, ...) | |||
462 | 453 | ||
463 | /* Become as one with the init task */ | 454 | /* Become as one with the init task */ |
464 | 455 | ||
465 | exit_fs(current); /* current->fs->count--; */ | 456 | daemonize_fs_struct(); |
466 | fs = init_task.fs; | ||
467 | current->fs = fs; | ||
468 | atomic_inc(&fs->count); | ||
469 | |||
470 | exit_files(current); | 457 | exit_files(current); |
471 | current->files = init_task.files; | 458 | current->files = init_task.files; |
472 | atomic_inc(¤t->files->count); | 459 | atomic_inc(¤t->files->count); |
@@ -565,30 +552,6 @@ void exit_files(struct task_struct *tsk) | |||
565 | } | 552 | } |
566 | } | 553 | } |
567 | 554 | ||
568 | void put_fs_struct(struct fs_struct *fs) | ||
569 | { | ||
570 | /* No need to hold fs->lock if we are killing it */ | ||
571 | if (atomic_dec_and_test(&fs->count)) { | ||
572 | path_put(&fs->root); | ||
573 | path_put(&fs->pwd); | ||
574 | kmem_cache_free(fs_cachep, fs); | ||
575 | } | ||
576 | } | ||
577 | |||
578 | void exit_fs(struct task_struct *tsk) | ||
579 | { | ||
580 | struct fs_struct * fs = tsk->fs; | ||
581 | |||
582 | if (fs) { | ||
583 | task_lock(tsk); | ||
584 | tsk->fs = NULL; | ||
585 | task_unlock(tsk); | ||
586 | put_fs_struct(fs); | ||
587 | } | ||
588 | } | ||
589 | |||
590 | EXPORT_SYMBOL_GPL(exit_fs); | ||
591 | |||
592 | #ifdef CONFIG_MM_OWNER | 555 | #ifdef CONFIG_MM_OWNER |
593 | /* | 556 | /* |
594 | * Task p is exiting and it owned mm, lets find a new owner for it | 557 | * Task p is exiting and it owned mm, lets find a new owner for it |
@@ -732,119 +695,6 @@ static void exit_mm(struct task_struct * tsk) | |||
732 | } | 695 | } |
733 | 696 | ||
734 | /* | 697 | /* |
735 | * Return nonzero if @parent's children should reap themselves. | ||
736 | * | ||
737 | * Called with write_lock_irq(&tasklist_lock) held. | ||
738 | */ | ||
739 | static int ignoring_children(struct task_struct *parent) | ||
740 | { | ||
741 | int ret; | ||
742 | struct sighand_struct *psig = parent->sighand; | ||
743 | unsigned long flags; | ||
744 | spin_lock_irqsave(&psig->siglock, flags); | ||
745 | ret = (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || | ||
746 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT)); | ||
747 | spin_unlock_irqrestore(&psig->siglock, flags); | ||
748 | return ret; | ||
749 | } | ||
750 | |||
751 | /* | ||
752 | * Detach all tasks we were using ptrace on. | ||
753 | * Any that need to be release_task'd are put on the @dead list. | ||
754 | * | ||
755 | * Called with write_lock(&tasklist_lock) held. | ||
756 | */ | ||
757 | static void ptrace_exit(struct task_struct *parent, struct list_head *dead) | ||
758 | { | ||
759 | struct task_struct *p, *n; | ||
760 | int ign = -1; | ||
761 | |||
762 | list_for_each_entry_safe(p, n, &parent->ptraced, ptrace_entry) { | ||
763 | __ptrace_unlink(p); | ||
764 | |||
765 | if (p->exit_state != EXIT_ZOMBIE) | ||
766 | continue; | ||
767 | |||
768 | /* | ||
769 | * If it's a zombie, our attachedness prevented normal | ||
770 | * parent notification or self-reaping. Do notification | ||
771 | * now if it would have happened earlier. If it should | ||
772 | * reap itself, add it to the @dead list. We can't call | ||
773 | * release_task() here because we already hold tasklist_lock. | ||
774 | * | ||
775 | * If it's our own child, there is no notification to do. | ||
776 | * But if our normal children self-reap, then this child | ||
777 | * was prevented by ptrace and we must reap it now. | ||
778 | */ | ||
779 | if (!task_detached(p) && thread_group_empty(p)) { | ||
780 | if (!same_thread_group(p->real_parent, parent)) | ||
781 | do_notify_parent(p, p->exit_signal); | ||
782 | else { | ||
783 | if (ign < 0) | ||
784 | ign = ignoring_children(parent); | ||
785 | if (ign) | ||
786 | p->exit_signal = -1; | ||
787 | } | ||
788 | } | ||
789 | |||
790 | if (task_detached(p)) { | ||
791 | /* | ||
792 | * Mark it as in the process of being reaped. | ||
793 | */ | ||
794 | p->exit_state = EXIT_DEAD; | ||
795 | list_add(&p->ptrace_entry, dead); | ||
796 | } | ||
797 | } | ||
798 | } | ||
799 | |||
800 | /* | ||
801 | * Finish up exit-time ptrace cleanup. | ||
802 | * | ||
803 | * Called without locks. | ||
804 | */ | ||
805 | static void ptrace_exit_finish(struct task_struct *parent, | ||
806 | struct list_head *dead) | ||
807 | { | ||
808 | struct task_struct *p, *n; | ||
809 | |||
810 | BUG_ON(!list_empty(&parent->ptraced)); | ||
811 | |||
812 | list_for_each_entry_safe(p, n, dead, ptrace_entry) { | ||
813 | list_del_init(&p->ptrace_entry); | ||
814 | release_task(p); | ||
815 | } | ||
816 | } | ||
817 | |||
818 | static void reparent_thread(struct task_struct *p, struct task_struct *father) | ||
819 | { | ||
820 | if (p->pdeath_signal) | ||
821 | /* We already hold the tasklist_lock here. */ | ||
822 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | ||
823 | |||
824 | list_move_tail(&p->sibling, &p->real_parent->children); | ||
825 | |||
826 | /* If this is a threaded reparent there is no need to | ||
827 | * notify anyone anything has happened. | ||
828 | */ | ||
829 | if (same_thread_group(p->real_parent, father)) | ||
830 | return; | ||
831 | |||
832 | /* We don't want people slaying init. */ | ||
833 | if (!task_detached(p)) | ||
834 | p->exit_signal = SIGCHLD; | ||
835 | |||
836 | /* If we'd notified the old parent about this child's death, | ||
837 | * also notify the new parent. | ||
838 | */ | ||
839 | if (!ptrace_reparented(p) && | ||
840 | p->exit_state == EXIT_ZOMBIE && | ||
841 | !task_detached(p) && thread_group_empty(p)) | ||
842 | do_notify_parent(p, p->exit_signal); | ||
843 | |||
844 | kill_orphaned_pgrp(p, father); | ||
845 | } | ||
846 | |||
847 | /* | ||
848 | * When we die, we re-parent all our children. | 698 | * When we die, we re-parent all our children. |
849 | * Try to give them to another thread in our thread | 699 | * Try to give them to another thread in our thread |
850 | * group, and if no such member exists, give it to | 700 | * group, and if no such member exists, give it to |
@@ -883,17 +733,51 @@ static struct task_struct *find_new_reaper(struct task_struct *father) | |||
883 | return pid_ns->child_reaper; | 733 | return pid_ns->child_reaper; |
884 | } | 734 | } |
885 | 735 | ||
736 | /* | ||
737 | * Any that need to be release_task'd are put on the @dead list. | ||
738 | */ | ||
739 | static void reparent_thread(struct task_struct *father, struct task_struct *p, | ||
740 | struct list_head *dead) | ||
741 | { | ||
742 | if (p->pdeath_signal) | ||
743 | group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p); | ||
744 | |||
745 | list_move_tail(&p->sibling, &p->real_parent->children); | ||
746 | |||
747 | if (task_detached(p)) | ||
748 | return; | ||
749 | /* | ||
750 | * If this is a threaded reparent there is no need to | ||
751 | * notify anyone anything has happened. | ||
752 | */ | ||
753 | if (same_thread_group(p->real_parent, father)) | ||
754 | return; | ||
755 | |||
756 | /* We don't want people slaying init. */ | ||
757 | p->exit_signal = SIGCHLD; | ||
758 | |||
759 | /* If it has exited notify the new parent about this child's death. */ | ||
760 | if (!p->ptrace && | ||
761 | p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) { | ||
762 | do_notify_parent(p, p->exit_signal); | ||
763 | if (task_detached(p)) { | ||
764 | p->exit_state = EXIT_DEAD; | ||
765 | list_move_tail(&p->sibling, dead); | ||
766 | } | ||
767 | } | ||
768 | |||
769 | kill_orphaned_pgrp(p, father); | ||
770 | } | ||
771 | |||
886 | static void forget_original_parent(struct task_struct *father) | 772 | static void forget_original_parent(struct task_struct *father) |
887 | { | 773 | { |
888 | struct task_struct *p, *n, *reaper; | 774 | struct task_struct *p, *n, *reaper; |
889 | LIST_HEAD(ptrace_dead); | 775 | LIST_HEAD(dead_children); |
776 | |||
777 | exit_ptrace(father); | ||
890 | 778 | ||
891 | write_lock_irq(&tasklist_lock); | 779 | write_lock_irq(&tasklist_lock); |
892 | reaper = find_new_reaper(father); | 780 | reaper = find_new_reaper(father); |
893 | /* | ||
894 | * First clean up ptrace if we were using it. | ||
895 | */ | ||
896 | ptrace_exit(father, &ptrace_dead); | ||
897 | 781 | ||
898 | list_for_each_entry_safe(p, n, &father->children, sibling) { | 782 | list_for_each_entry_safe(p, n, &father->children, sibling) { |
899 | p->real_parent = reaper; | 783 | p->real_parent = reaper; |
@@ -901,13 +785,16 @@ static void forget_original_parent(struct task_struct *father) | |||
901 | BUG_ON(p->ptrace); | 785 | BUG_ON(p->ptrace); |
902 | p->parent = p->real_parent; | 786 | p->parent = p->real_parent; |
903 | } | 787 | } |
904 | reparent_thread(p, father); | 788 | reparent_thread(father, p, &dead_children); |
905 | } | 789 | } |
906 | |||
907 | write_unlock_irq(&tasklist_lock); | 790 | write_unlock_irq(&tasklist_lock); |
791 | |||
908 | BUG_ON(!list_empty(&father->children)); | 792 | BUG_ON(!list_empty(&father->children)); |
909 | 793 | ||
910 | ptrace_exit_finish(father, &ptrace_dead); | 794 | list_for_each_entry_safe(p, n, &dead_children, sibling) { |
795 | list_del_init(&p->sibling); | ||
796 | release_task(p); | ||
797 | } | ||
911 | } | 798 | } |
912 | 799 | ||
913 | /* | 800 | /* |
@@ -1419,6 +1306,18 @@ static int wait_task_zombie(struct task_struct *p, int options, | |||
1419 | return retval; | 1306 | return retval; |
1420 | } | 1307 | } |
1421 | 1308 | ||
1309 | static int *task_stopped_code(struct task_struct *p, bool ptrace) | ||
1310 | { | ||
1311 | if (ptrace) { | ||
1312 | if (task_is_stopped_or_traced(p)) | ||
1313 | return &p->exit_code; | ||
1314 | } else { | ||
1315 | if (p->signal->flags & SIGNAL_STOP_STOPPED) | ||
1316 | return &p->signal->group_exit_code; | ||
1317 | } | ||
1318 | return NULL; | ||
1319 | } | ||
1320 | |||
1422 | /* | 1321 | /* |
1423 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold | 1322 | * Handle sys_wait4 work for one task in state TASK_STOPPED. We hold |
1424 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold | 1323 | * read_lock(&tasklist_lock) on entry. If we return zero, we still hold |
@@ -1429,7 +1328,7 @@ static int wait_task_stopped(int ptrace, struct task_struct *p, | |||
1429 | int options, struct siginfo __user *infop, | 1328 | int options, struct siginfo __user *infop, |
1430 | int __user *stat_addr, struct rusage __user *ru) | 1329 | int __user *stat_addr, struct rusage __user *ru) |
1431 | { | 1330 | { |
1432 | int retval, exit_code, why; | 1331 | int retval, exit_code, *p_code, why; |
1433 | uid_t uid = 0; /* unneeded, required by compiler */ | 1332 | uid_t uid = 0; /* unneeded, required by compiler */ |
1434 | pid_t pid; | 1333 | pid_t pid; |
1435 | 1334 | ||
@@ -1439,22 +1338,16 @@ static int wait_task_stopped(int ptrace, struct task_struct *p, | |||
1439 | exit_code = 0; | 1338 | exit_code = 0; |
1440 | spin_lock_irq(&p->sighand->siglock); | 1339 | spin_lock_irq(&p->sighand->siglock); |
1441 | 1340 | ||
1442 | if (unlikely(!task_is_stopped_or_traced(p))) | 1341 | p_code = task_stopped_code(p, ptrace); |
1443 | goto unlock_sig; | 1342 | if (unlikely(!p_code)) |
1444 | |||
1445 | if (!ptrace && p->signal->group_stop_count > 0) | ||
1446 | /* | ||
1447 | * A group stop is in progress and this is the group leader. | ||
1448 | * We won't report until all threads have stopped. | ||
1449 | */ | ||
1450 | goto unlock_sig; | 1343 | goto unlock_sig; |
1451 | 1344 | ||
1452 | exit_code = p->exit_code; | 1345 | exit_code = *p_code; |
1453 | if (!exit_code) | 1346 | if (!exit_code) |
1454 | goto unlock_sig; | 1347 | goto unlock_sig; |
1455 | 1348 | ||
1456 | if (!unlikely(options & WNOWAIT)) | 1349 | if (!unlikely(options & WNOWAIT)) |
1457 | p->exit_code = 0; | 1350 | *p_code = 0; |
1458 | 1351 | ||
1459 | /* don't need the RCU readlock here as we're holding a spinlock */ | 1352 | /* don't need the RCU readlock here as we're holding a spinlock */ |
1460 | uid = __task_cred(p)->uid; | 1353 | uid = __task_cred(p)->uid; |
@@ -1610,7 +1503,7 @@ static int wait_consider_task(struct task_struct *parent, int ptrace, | |||
1610 | */ | 1503 | */ |
1611 | *notask_error = 0; | 1504 | *notask_error = 0; |
1612 | 1505 | ||
1613 | if (task_is_stopped_or_traced(p)) | 1506 | if (task_stopped_code(p, ptrace)) |
1614 | return wait_task_stopped(ptrace, p, options, | 1507 | return wait_task_stopped(ptrace, p, options, |
1615 | infop, stat_addr, ru); | 1508 | infop, stat_addr, ru); |
1616 | 1509 | ||
@@ -1814,7 +1707,7 @@ SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr, | |||
1814 | pid = find_get_pid(-upid); | 1707 | pid = find_get_pid(-upid); |
1815 | } else if (upid == 0) { | 1708 | } else if (upid == 0) { |
1816 | type = PIDTYPE_PGID; | 1709 | type = PIDTYPE_PGID; |
1817 | pid = get_pid(task_pgrp(current)); | 1710 | pid = get_task_pid(current, PIDTYPE_PGID); |
1818 | } else /* upid > 0 */ { | 1711 | } else /* upid > 0 */ { |
1819 | type = PIDTYPE_PID; | 1712 | type = PIDTYPE_PID; |
1820 | pid = find_get_pid(upid); | 1713 | pid = find_get_pid(upid); |