Messages in this thread | | | From | David Howells <> | Subject | Re: [PATCH 1/2] creds: kill __task_cred()->task_is_dead() check | Date | Tue, 20 Sep 2011 17:27:30 +0100 |
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Oleg Nesterov <oleg@redhat.com> wrote:
> From 8f92054e commit: > > Instead, add the following validation condition: > > task->exit_state >= 0 > > to permit the access if the target task is dead and therefore unable to change > its own credentials. > > OK, but afaics currently this can only help wait_task_zombie() which > calls __task_cred() without rcu lock. > > Remove this validation and change wait_task_zombie() to use task_uid() > instead. This means we do rcu_read_lock() only to shut up the lockdep, > but we already do the same in, say, wait_task_stopped(). > > Unfortunately, we can't kill task_is_dead() right now, it has already > found the users in drivers/staging/, and I bet the usage is wrong. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
It simplifies stuff in exchange for the most minor of slowdowns, so fair enough.
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