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

[Chen Gang]

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@xxxxxxxxxxxxxxxxxxxx>
> Reported-by: Chen Gang <gang.chen@xxxxxxxxxxx>
> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> Cc: Stanislaw Gruszka <sgruszka@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxx>
> Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
> Cc: Chen Gang <gang.chen@xxxxxxxxxxx>
> ---

  thank you for mark me as reported by, although I reported too late
(Andrew Morton is the first reporter).

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

  :-)

-- 
Chen Gang

Asianux Corporation
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