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authorDavid S. Miller <davem@davemloft.net>2008-09-08 19:59:05 -0400
committerDavid S. Miller <davem@davemloft.net>2008-09-08 19:59:05 -0400
commit17dce5dfe38ae2fb359b61e855f5d8a3a8b7892b (patch)
tree88bb1fcf84f9ebfa4299c9a8dcd9e6330b358446 /kernel/exit.c
parent712d6954e3998d0de2840d8130941e8042541246 (diff)
parent82a28c794f27aac17d7a3ebd7f14d731a11a5532 (diff)
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts: net/mac80211/mlme.c
Diffstat (limited to 'kernel/exit.c')
-rw-r--r--kernel/exit.c88
1 files changed, 39 insertions, 49 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 38ec40630149..16395644a98f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -112,9 +112,9 @@ static void __exit_signal(struct task_struct *tsk)
112 * We won't ever get here for the group leader, since it 112 * We won't ever get here for the group leader, since it
113 * will have been the last reference on the signal_struct. 113 * will have been the last reference on the signal_struct.
114 */ 114 */
115 sig->utime = cputime_add(sig->utime, tsk->utime); 115 sig->utime = cputime_add(sig->utime, task_utime(tsk));
116 sig->stime = cputime_add(sig->stime, tsk->stime); 116 sig->stime = cputime_add(sig->stime, task_stime(tsk));
117 sig->gtime = cputime_add(sig->gtime, tsk->gtime); 117 sig->gtime = cputime_add(sig->gtime, task_gtime(tsk));
118 sig->min_flt += tsk->min_flt; 118 sig->min_flt += tsk->min_flt;
119 sig->maj_flt += tsk->maj_flt; 119 sig->maj_flt += tsk->maj_flt;
120 sig->nvcsw += tsk->nvcsw; 120 sig->nvcsw += tsk->nvcsw;
@@ -831,26 +831,50 @@ static void reparent_thread(struct task_struct *p, struct task_struct *father)
831 * the child reaper process (ie "init") in our pid 831 * the child reaper process (ie "init") in our pid
832 * space. 832 * space.
833 */ 833 */
834static struct task_struct *find_new_reaper(struct task_struct *father)
835{
836 struct pid_namespace *pid_ns = task_active_pid_ns(father);
837 struct task_struct *thread;
838
839 thread = father;
840 while_each_thread(father, thread) {
841 if (thread->flags & PF_EXITING)
842 continue;
843 if (unlikely(pid_ns->child_reaper == father))
844 pid_ns->child_reaper = thread;
845 return thread;
846 }
847
848 if (unlikely(pid_ns->child_reaper == father)) {
849 write_unlock_irq(&tasklist_lock);
850 if (unlikely(pid_ns == &init_pid_ns))
851 panic("Attempted to kill init!");
852
853 zap_pid_ns_processes(pid_ns);
854 write_lock_irq(&tasklist_lock);
855 /*
856 * We can not clear ->child_reaper or leave it alone.
857 * There may by stealth EXIT_DEAD tasks on ->children,
858 * forget_original_parent() must move them somewhere.
859 */
860 pid_ns->child_reaper = init_pid_ns.child_reaper;
861 }
862
863 return pid_ns->child_reaper;
864}
865
834static void forget_original_parent(struct task_struct *father) 866static void forget_original_parent(struct task_struct *father)
835{ 867{
836 struct task_struct *p, *n, *reaper = father; 868 struct task_struct *p, *n, *reaper;
837 LIST_HEAD(ptrace_dead); 869 LIST_HEAD(ptrace_dead);
838 870
839 write_lock_irq(&tasklist_lock); 871 write_lock_irq(&tasklist_lock);
840 872 reaper = find_new_reaper(father);
841 /* 873 /*
842 * First clean up ptrace if we were using it. 874 * First clean up ptrace if we were using it.
843 */ 875 */
844 ptrace_exit(father, &ptrace_dead); 876 ptrace_exit(father, &ptrace_dead);
845 877
846 do {
847 reaper = next_thread(reaper);
848 if (reaper == father) {
849 reaper = task_child_reaper(father);
850 break;
851 }
852 } while (reaper->flags & PF_EXITING);
853
854 list_for_each_entry_safe(p, n, &father->children, sibling) { 878 list_for_each_entry_safe(p, n, &father->children, sibling) {
855 p->real_parent = reaper; 879 p->real_parent = reaper;
856 if (p->parent == father) { 880 if (p->parent == father) {
@@ -918,8 +942,8 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
918 942
919 /* mt-exec, de_thread() is waiting for us */ 943 /* mt-exec, de_thread() is waiting for us */
920 if (thread_group_leader(tsk) && 944 if (thread_group_leader(tsk) &&
921 tsk->signal->notify_count < 0 && 945 tsk->signal->group_exit_task &&
922 tsk->signal->group_exit_task) 946 tsk->signal->notify_count < 0)
923 wake_up_process(tsk->signal->group_exit_task); 947 wake_up_process(tsk->signal->group_exit_task);
924 948
925 write_unlock_irq(&tasklist_lock); 949 write_unlock_irq(&tasklist_lock);
@@ -959,39 +983,6 @@ static void check_stack_usage(void)
959static inline void check_stack_usage(void) {} 983static inline void check_stack_usage(void) {}
960#endif 984#endif
961 985
962static inline void exit_child_reaper(struct task_struct *tsk)
963{
964 if (likely(tsk->group_leader != task_child_reaper(tsk)))
965 return;
966
967 if (tsk->nsproxy->pid_ns == &init_pid_ns)
968 panic("Attempted to kill init!");
969
970 /*
971 * @tsk is the last thread in the 'cgroup-init' and is exiting.
972 * Terminate all remaining processes in the namespace and reap them
973 * before exiting @tsk.
974 *
975 * Note that @tsk (last thread of cgroup-init) may not necessarily
976 * be the child-reaper (i.e main thread of cgroup-init) of the
977 * namespace i.e the child_reaper may have already exited.
978 *
979 * Even after a child_reaper exits, we let it inherit orphaned children,
980 * because, pid_ns->child_reaper remains valid as long as there is
981 * at least one living sub-thread in the cgroup init.
982
983 * This living sub-thread of the cgroup-init will be notified when
984 * a child inherited by the 'child-reaper' exits (do_notify_parent()
985 * uses __group_send_sig_info()). Further, when reaping child processes,
986 * do_wait() iterates over children of all living sub threads.
987
988 * i.e even though 'child_reaper' thread is listed as the parent of the
989 * orphaned children, any living sub-thread in the cgroup-init can
990 * perform the role of the child_reaper.
991 */
992 zap_pid_ns_processes(tsk->nsproxy->pid_ns);
993}
994
995NORET_TYPE void do_exit(long code) 986NORET_TYPE void do_exit(long code)
996{ 987{
997 struct task_struct *tsk = current; 988 struct task_struct *tsk = current;
@@ -1051,7 +1042,6 @@ NORET_TYPE void do_exit(long code)
1051 } 1042 }
1052 group_dead = atomic_dec_and_test(&tsk->signal->live); 1043 group_dead = atomic_dec_and_test(&tsk->signal->live);
1053 if (group_dead) { 1044 if (group_dead) {
1054 exit_child_reaper(tsk);
1055 hrtimer_cancel(&tsk->signal->real_timer); 1045 hrtimer_cancel(&tsk->signal->real_timer);
1056 exit_itimers(tsk->signal); 1046 exit_itimers(tsk->signal);
1057 } 1047 }