[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
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.) Other subsystem may put lock_task_sighand() into rcu_read_lock() critical region, but these rcu_read_lock() are used for protecting "for_each_process()", "find_task_by_vpid()" etc. , not for protecting lock_task_sighand(). Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com> [ok from Oleg] Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
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