Re: oom: __task_cred() need rcu_read_lock()

[KOSAKI Motohiro]

Hi

> KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
> 
> > dump_tasks() can call __task_cred() safely because we are holding
> > tasklist_lock. but rcu lock validator don't have enough knowledge and
> > it makes following annoying warning.
> 
> No, it can't.  The tasklist_lock is not protection against the creds changing
> on another CPU.

Thank you for correction.

I suppose you mean I missed CONFIG_TREE_PREEMPT_RCU, right?
As far as my grepping, other rcu implementation and spinlock use 
preempt_disable(). In other word, Can I assume usual distro user 
don't hit this issue?

Thanks.



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