commit 0aad4b3124 (oom: fold __out_of_memory into out_of_memory)
introduced tasklist_lock leak. Then it caused following obvious
danger warings and panic.
================================================
[ BUG: lock held when returning to user space! ]
------------------------------------------------
rsyslogd/1422 is leaving the kernel with locks still held!
1 lock held by rsyslogd/1422:
#0: (tasklist_lock){.+.+.+}, at: [<ffffffff810faf64>] out_of_memory+0x164/0x3f0
BUG: scheduling while atomic: rsyslogd/1422/0x00000002
INFO: lockdep is turned off.
This patch fixes it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
---
mm/oom_kill.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 17d48a6..c48c5ef 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -646,6 +646,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
unsigned long freed = 0;
unsigned int points;
enum oom_constraint constraint = CONSTRAINT_NONE;
+ int killed = 0;
blocking_notifier_call_chain(&oom_notify_list, 0, &freed);
if (freed > 0)
@@ -683,7 +684,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
if (!oom_kill_process(current, gfp_mask, order, 0, totalpages,
NULL, nodemask,
"Out of memory (oom_kill_allocating_task)"))
- return;
+ goto out;
}
retry:
@@ -691,7 +692,7 @@ retry:
constraint == CONSTRAINT_MEMORY_POLICY ? nodemask :
NULL);
if (PTR_ERR(p) == -1UL)
- return;
+ goto out;
/* Found nothing?!?! Either we hang forever, or we panic. */
if (!p) {
@@ -703,13 +704,15 @@ retry:
if (oom_kill_process(p, gfp_mask, order, points, totalpages, NULL,
nodemask, "Out of memory"))
goto retry;
+ killed = 1;
+out:
read_unlock(&tasklist_lock);
/*
* Give "p" a good chance of killing itself before we
* retry to allocate memory unless "p" is current
*/
- if (!test_thread_flag(TIF_MEMDIE))
+ if (killed && !test_thread_flag(TIF_MEMDIE))
schedule_timeout_uninterruptible(1);
}
--
1.6.5.2
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