[PATCH] posix-timers: fix task accounting

Make sure we release the task struct properly when releasing pending
timers.

release_task() does write_lock_irq(&tasklist_lock), so it can't race
with run_posix_cpu_timers() on any cpu.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index ad85d3f0dcc4..7a51a5597c33 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -424,6 +424,7 @@ static void cleanup_timers(struct list_head *head,
         cputime_t ptime = cputime_add(utime, stime);
 
         list_for_each_entry_safe(timer, next, head, entry) {
+                put_task_struct(timer->task);
                 timer->task = NULL;
                 list_del_init(&timer->entry);
                 if (cputime_lt(timer->expires.cpu, ptime)) {
@@ -436,6 +437,7 @@ static void cleanup_timers(struct list_head *head,
 
         ++head;
         list_for_each_entry_safe(timer, next, head, entry) {
+                put_task_struct(timer->task);
                 timer->task = NULL;
                 list_del_init(&timer->entry);
                 if (cputime_lt(timer->expires.cpu, utime)) {
@@ -448,6 +450,7 @@ static void cleanup_timers(struct list_head *head,
 
         ++head;
         list_for_each_entry_safe(timer, next, head, entry) {
+                put_task_struct(timer->task);
                 timer->task = NULL;
                 list_del_init(&timer->entry);
                 if (timer->expires.sched < sched_time) {