The wait_task_interactive() will have a task sleep waiting for another
task to have a certain state. But it ignores the rt_spin_locks state
and can return with an incorrect result if the task it is waiting
for is blocked on a rt_spin_lock() and is waking up.
The rt_spin_locks save the tasks state in the saved_state field
and the wait_task_interactive() must also test that state.
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/sched.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/kernel/sched.c b/kernel/sched.c
index 81b340d..1cc706d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2450,7 +2450,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
* is actually now running somewhere else!
*/
while (task_running(rq, p)) {
- if (match_state && unlikely(p->state != match_state))
+ if (match_state && unlikely(p->state != match_state)
+ && unlikely(p->saved_state != match_state))
return 0;
cpu_relax();
}
@@ -2465,7 +2466,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
running = task_running(rq, p);
on_rq = p->on_rq;
ncsw = 0;
- if (!match_state || p->state == match_state)
+ if (!match_state || p->state == match_state
+ || p->saved_state == match_state)
ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
task_rq_unlock(rq, p, &flags);
--
1.7.3.4
--
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