Commit-ID: 185b42420b0948dfc00af6cc5d93aa00b7fef581
Gitweb: http://git.kernel.org/tip/185b42420b0948dfc00af6cc5d93aa00b7fef581
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Tue, 29 Sep 2015 11:28:28 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 29 Sep 2015 12:27:40 +0200
sched/core: Robustify preemption leak checks
When we warn about a preempt_count leak; reset the preempt_count
to the known good value such that the problem does not ripple
forward.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: fweisbec@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: oleg@xxxxxxxxxx
Cc: rostedt@xxxxxxxxxxx
Cc: umgwanakikbuti@xxxxxxxxx
Link: http://lkml.kernel.org/r/20150929093519.930244771@xxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/exit.c | 4 +++-
kernel/sched/core.c | 4 +++-
2 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index ea95ee1..443677c 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -706,10 +706,12 @@ void do_exit(long code)
smp_mb();
raw_spin_unlock_wait(&tsk->pi_lock);
- if (unlikely(in_atomic()))
+ if (unlikely(in_atomic())) {
pr_info("note: %s[%d] exited with preempt_count %d\n",
current->comm, task_pid_nr(current),
preempt_count());
+ preempt_count_set(PREEMPT_ENABLED);
+ }
/* sync mm's RSS info before statistics gathering */
if (tsk->mm)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ecd585c..d1dec5d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2953,8 +2953,10 @@ static inline void schedule_debug(struct task_struct *prev)
* schedule() atomically, we ignore that path. Otherwise whine
* if we are scheduling when we should not.
*/
- if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD))
+ if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD)) {
__schedule_bug(prev);
+ preempt_count_set(PREEMPT_DISABLED);
+ }
rcu_sleep_check();
profile_hit(SCHED_PROFILING, __builtin_return_address(0));
--
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