diff options
| author | David Rientjes <rientjes@google.com> | 2009-05-28 14:34:19 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-05-29 08:40:01 -0700 |
| commit | 6d2661ede5f20f968422e790af3334908c3bc857 (patch) | |
| tree | 2e002d883eee9be5c52d844a7b0c3354338d8995 /mm | |
| parent | 681a1b4032d72f4ad6d4beed751bc65574572746 (diff) | |
| download | lwn-6d2661ede5f20f968422e790af3334908c3bc857.tar.gz lwn-6d2661ede5f20f968422e790af3334908c3bc857.zip | |
oom: fix possible oom_dump_tasks NULL pointer
When /proc/sys/vm/oom_dump_tasks is enabled, it is possible to get a NULL
pointer for tasks that have detached mm's since task_lock() is not held
during the tasklist scan. Add the task_lock().
Acked-by: Nick Piggin <npiggin@suse.de>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-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')
| -rw-r--r-- | mm/oom_kill.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 92bcf1db16b2..a7b2460e922b 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -284,22 +284,28 @@ static void dump_tasks(const struct mem_cgroup *mem) printk(KERN_INFO "[ pid ] uid tgid total_vm rss cpu oom_adj " "name\n"); do_each_thread(g, p) { - /* - * total_vm and rss sizes do not exist for tasks with a - * detached mm so there's no need to report them. - */ - if (!p->mm) - continue; + struct mm_struct *mm; + if (mem && !task_in_mem_cgroup(p, mem)) continue; if (!thread_group_leader(p)) continue; task_lock(p); + mm = p->mm; + if (!mm) { + /* + * total_vm and rss sizes do not exist for tasks with no + * mm so there's no need to report them; they can't be + * oom killed anyway. + */ + task_unlock(p); + continue; + } printk(KERN_INFO "[%5d] %5d %5d %8lu %8lu %3d %3d %s\n", - p->pid, __task_cred(p)->uid, p->tgid, - p->mm->total_vm, get_mm_rss(p->mm), (int)task_cpu(p), - p->oomkilladj, p->comm); + p->pid, __task_cred(p)->uid, p->tgid, mm->total_vm, + get_mm_rss(mm), (int)task_cpu(p), p->oomkilladj, + p->comm); task_unlock(p); } while_each_thread(g, p); } |