| Message ID | 1410818884-8413-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/mm/util.c b/mm/util.c index 8636d3d..89abc97 100644 --- a/mm/util.c +++ b/mm/util.c @@ -276,17 +276,14 @@ 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(); }
This is a note to let you know that I have just added a patch titled vm_is_stack: use for_each_thread() rather then buggy while_each_thread() to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue This patch is scheduled to be released in version 3.13.11.7. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From adb734b4effae71eb08df3a8610b22ffc629203c Mon Sep 17 00:00:00 2001 From: Oleg Nesterov <oleg@redhat.com> Date: Fri, 8 Aug 2014 14:19:17 -0700 Subject: 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: Kamal Mostafa <kamal@canonical.com> --- mm/util.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) -- 1.9.1