diff options
| author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2010-08-19 14:13:39 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-20 09:34:55 -0700 |
| commit | b52723c5607f7684c2c0c075f86f86da0d7fb6d0 (patch) | |
| tree | 97db08ef9d74c8fcacff6a96070854a5bc276419 /mm/oom_kill.c | |
| parent | be71cf2202971e50ce4953d473649c724799eb8a (diff) | |
| download | lwn-b52723c5607f7684c2c0c075f86f86da0d7fb6d0.tar.gz lwn-b52723c5607f7684c2c0c075f86f86da0d7fb6d0.zip | |
oom: fix tasklist_lock leak
Commit 0aad4b3124 ("oom: fold __out_of_memory into out_of_memory")
introduced a tasklist_lock leak. Then it caused following obvious
danger warnings 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@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/oom_kill.c')
| -rw-r--r-- | 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 17d48a67e7b7..c48c5ef3ccfd 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); } |