Messages in this thread | | | Date | Fri, 3 Oct 2008 20:29:15 +0400 | From | Oleg Nesterov <> | Subject | Re: [PATCH] signal, procfs: lock_task_sighand() do not need rcu_read_lock() |
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On 10/03, Lai Jiangshan wrote: > > lock_task_sighand() make sure task->sighand is being protected, > so we do not need rcu_read_lock(). > [ exec() will get task->sighand->siglock before change task->sighand! ] > > But code using rcu_read_lock() _just_ to protect lock_task_sighand() > only appear in procfs. (and some code in procfs use lock_task_sighand() > without such redundant protection.)
Yes, the patch looks correct.
The initial implementaion of lock_task_sighand() did not take RCU lock, that is why we still have the callers which call rcu_read_lock(). See 1406f2d321bae5ac5ff729dcb773336d9c05ec74.
Thanks!
Oleg.
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