Messages in this thread | | | Subject | Re: __update_max_tr: rcu_read_lock() used illegally while idle! | From | Steven Rostedt <> | Date | Tue, 31 Jul 2012 10:51:51 -0400 |
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On Tue, 2012-07-31 at 07:44 -0700, Paul E. McKenney wrote:
> > Found it (and Cc'd David). > > > > In __update_max_tr() we have: > > > > max_data = task_uid(tsk); > > > > where task_uid() is: > > > > #define task_uid(task) (task_cred_xxx((task), uid)) > > > > #define task_cred_xxx(task, xxx) \ > > ({ \ > > __typeof__(((struct cred *)NULL)->xxx) ___val; \ > > rcu_read_lock(); \ > > ___val = __task_cred((task))->xxx; \ > > rcu_read_unlock(); \ > > ___val; \ > > }) > > > > The __update_max_tr() is called at every location interrupts are enabled > > (and a max time is discovered). But now this can include places that > > rcu_read_lock can not be called, I'm not sure how to handle this. Is > > there a non rcu way to get a tasks uid? > > OK, I will bite. How about using something like RCU_NONIDLE(), either > directly or open-coded, to make it a legal call site?
OK, then something like:
RCU_NONIDLE(max_data = task_uid(tsk));
would work when called normally or with idle?
-- Steve
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