Commit 4449a51a authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

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: default avatarOleg Nesterov <oleg@redhat.com>
Reported-by: default avatarAleksei Besogonov <alex.besogonov@gmail.com>
Tested-by: default avatarAleksei Besogonov <alex.besogonov@gmail.com>
Suggested-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent edcad250
...@@ -183,17 +183,14 @@ pid_t vm_is_stack(struct task_struct *task, ...@@ -183,17 +183,14 @@ pid_t vm_is_stack(struct task_struct *task,
if (in_group) { if (in_group) {
struct task_struct *t; struct task_struct *t;
rcu_read_lock();
if (!pid_alive(task))
goto done;
t = task; rcu_read_lock();
do { for_each_thread(task, t) {
if (vm_is_stack_for_task(t, vma)) { if (vm_is_stack_for_task(t, vma)) {
ret = t->pid; ret = t->pid;
goto done; goto done;
} }
} while_each_thread(task, t); }
done: done:
rcu_read_unlock(); rcu_read_unlock();
} }
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment