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Date: Sat, 21 Jun 2014 21:54:59 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Steven Rostedt <rostedt@goodmis.org>
cc: Oleg Nesterov <oleg@redhat.com>,
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        Andrew Morton <akpm@linux-foundation.org>,
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Subject: Re: safety of *mutex_unlock() (Was: [BUG] signal: sighand unprotected
 when accessed by /proc)
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On Wed, 18 Jun 2014, Steven Rostedt wrote:

> On Wed, 18 Jun 2014 18:43:59 +0200
> Oleg Nesterov <oleg@redhat.com> wrote:
> 
>  
> > And (contrary to what I said initially) we can rely on this because -rt
> > converts spinlock_t into rt_mutex ?
> 
> Correct. Because if spinlock_t has this behavior, rt_mutex must have it
> too, otherwise -rt will suffer greatly from that. Who knows, maybe this
> will fix some strange bug reports that we have had in the past.

Indeed. I found a few backtraces from Carstens test farm, where stuff
explodes in the slowpath raw_spin_unlock call. Happens once a year or
never ...

Thanks,

	tglx