diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2014-08-08 14:19:17 -0700 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-09-17 15:12:24 +0200 |
| commit | d9cd4a157bb0068a044552015bdf0020d21bbfd4 (patch) | |
| tree | 2e9848d46586d38007b804ca4321da558a8c750a /mm/util.c | |
| parent | 24bafe7dfd3771f280cbd3074b1dfff62aa7715d (diff) | |
vm_is_stack: use for_each_thread() rather then buggy while_each_thread()
commit 4449a51a7c281602d3a385044ab928322a122a02 upstream.
Aleksei hit the soft lockup during reading /proc/PID/smaps. David
investigated the problem and suggested the right fix.
while_each_thread() is racy and should die, this patch updates
vm_is_stack().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Aleksei Besogonov <alex.besogonov@gmail.com>
Tested-by: Aleksei Besogonov <alex.besogonov@gmail.com>
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/mm/util.c b/mm/util.c index 96da2d7c076c..de943ec0a4c8 100644 --- a/mm/util.c +++ b/mm/util.c @@ -272,17 +272,14 @@ pid_t vm_is_stack(struct task_struct *task, if (in_group) { struct task_struct *t; - rcu_read_lock(); - if (!pid_alive(task)) - goto done; - t = task; - do { + rcu_read_lock(); + for_each_thread(task, t) { if (vm_is_stack_for_task(t, vma)) { ret = t->pid; goto done; } - } while_each_thread(task, t); + } done: rcu_read_unlock(); } |