Re: [PATCH 1/3] posix-timers: Correctly get dying task time sample in posix_cpu_timer_schedule()

[Frederic Weisbecker <fweisbec@gmail.com>]

On Mon, Apr 01, 2013 at 08:07:59AM +0800, Chen Gang wrote:
> On 2013年03月30日 21:15, Frederic Weisbecker wrote:
> > In order to arm the next timer to schedule, we take a sample of the
> > current process or thread cputime.
> > 
> > If the task is dying though, we don't arm anything but we
> > cache the remaining timer expiration delta for further reads.
> > 
> > Something similar is performed in posix_cpu_timer_get() but
> > here we forget to take the process wide cputime sample
> > before caching it.
> > 
> > As a result we are storing random stack content, leading
> > every further reads of that timer to return junk values.
> > 
> > Fix this by taking the appropriate sample in the case of
> > process wide timers.
> > 
> > Reported-by: Andrew Morton <akpm@linux-foundation.org>
> > Reported-by: Chen Gang <gang.chen@asianux.com>
> > Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
> > Cc: Stanislaw Gruszka <sgruszka@redhat.com>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > Cc: Ingo Molnar <mingo@elte.hu>
> > Cc: Oleg Nesterov <oleg@redhat.com>
> > Cc: Chen Gang <gang.chen@asianux.com>
> > ---
> 
>   thank you for mark me as reported by, although I reported too late
> (Andrew Morton is the first reporter).

Bug reporters simply deserve to be credited, no sorting is required ;)

> 
>   next, I should continue to try to find another issues about kernel.

I encourage you to do so :)

Thanks.