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| author | Oleg Nesterov <oleg@redhat.com> | 2014-08-08 14:19:17 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-08 15:57:17 -0700 |
| commit | 4449a51a7c281602d3a385044ab928322a122a02 (patch) | |
| tree | 22d23d36c1e64938b75945160394d9e625939321 /mm/util.c | |
| parent | edcad25095503c9a390bea0cc2f518793447a6a8 (diff) | |
| download | linux-rpi3-4449a51a7c281602d3a385044ab928322a122a02.tar.gz linux-rpi3-4449a51a7c281602d3a385044ab928322a122a02.tar.bz2 linux-rpi3-4449a51a7c281602d3a385044ab928322a122a02.zip | |
vm_is_stack: use for_each_thread() rather then buggy while_each_thread()
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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 7b6608df2ee8..093c973f1697 100644 --- a/mm/util.c +++ b/mm/util.c @@ -183,17 +183,14 @@ 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(); } |