From: Andy Lutomirski <luto@amacapital.net>
To: Waiman Long <waiman.long@hp.com>
Cc: Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Scott J Norton <scott.norton@hp.com>,
Aswin Chandramouleeswaran <aswin@hp.com>,
tip-bot for Peter Zijlstra <tipbot@zytor.com>,
linux-tip-commits@vger.kernel.org
Subject: Re: [tip:perf/core] x86, mm, perf: Allow recursive faults from interrupts
Date: Fri, 17 Jan 2014 11:17:38 -0800 [thread overview]
Message-ID: <CALCETrWF4AwFrBrA1WdrEUj5=oPfiPPUF7PJCooagTi6Y07Pwg@mail.gmail.com> (raw)
In-Reply-To: <52D971FE.9030008@hp.com>
On Fri, Jan 17, 2014 at 10:10 AM, Waiman Long <waiman.long@hp.com> wrote:
> On 01/16/2014 08:39 AM, tip-bot for Peter Zijlstra wrote:
>>
>> Commit-ID: c026b3591e4f2a4993df773183704bb31634e0bd
>> Gitweb:
>> http://git.kernel.org/tip/c026b3591e4f2a4993df773183704bb31634e0bd
>> Author: Peter Zijlstra<peterz@infradead.org>
>> AuthorDate: Fri, 10 Jan 2014 21:06:03 +0100
>> Committer: Ingo Molnar<mingo@kernel.org>
>> CommitDate: Thu, 16 Jan 2014 09:19:48 +0100
>>
>> x86, mm, perf: Allow recursive faults from interrupts
>>
>> Waiman managed to trigger a PMI while in a emulate_vsyscall() fault,
>> the PMI in turn managed to trigger a fault while obtaining a stack
>> trace. This triggered the sig_on_uaccess_error recursive fault logic
>> and killed the process dead.
>>
>> Fix this by explicitly excluding interrupts from the recursive fault
>> logic.
>>
>> Reported-and-Tested-by: Waiman Long<waiman.long@hp.com>
>> Fixes: e00b12e64be9 ("perf/x86: Further optimize copy_from_user_nmi()")
>> Cc: Aswin Chandramouleeswaran<aswin@hp.com>
>> Cc: Scott J Norton<scott.norton@hp.com>
>> Cc: Linus Torvalds<torvalds@linux-foundation.org>
>> Cc: Andy Lutomirski<luto@amacapital.net>
>> Cc: Arnaldo Carvalho de Melo<acme@ghostprotocols.net>
>> Cc: Andrew Morton<akpm@linux-foundation.org>
>> Signed-off-by: Peter Zijlstra<peterz@infradead.org>
>> Link:
>> http://lkml.kernel.org/r/20140110200603.GJ7572@laptop.programming.kicks-ass.net
>> Signed-off-by: Ingo Molnar<mingo@kernel.org>
>> ---
>> arch/x86/mm/fault.c | 18 ++++++++++++++++++
>> 1 file changed, 18 insertions(+)
>>
>>
>
> Will that be picked up by Linus as it is a 3.13 regression?
Does anyone actually know why this regressed recently? The buggy code
has been there for quite a while.
--Andy
next prev parent reply other threads:[~2014-01-17 19:18 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-10 15:29 SIGSEGV when using "perf record -g" with 3.13-rc* kernel Waiman Long
2014-01-10 16:58 ` Peter Zijlstra
2014-01-10 17:02 ` Peter Zijlstra
2014-01-10 17:41 ` Peter Zijlstra
2014-01-10 18:54 ` Andy Lutomirski
2014-01-10 19:43 ` Waiman Long
2014-01-10 19:56 ` Andy Lutomirski
2014-01-10 20:12 ` Peter Zijlstra
2014-01-10 20:06 ` Peter Zijlstra
2014-01-10 20:28 ` Andy Lutomirski
2014-01-15 15:33 ` Waiman Long
2014-01-16 13:39 ` [tip:perf/core] x86, mm, perf: Allow recursive faults from interrupts tip-bot for Peter Zijlstra
2014-01-17 18:10 ` Waiman Long
2014-01-17 19:17 ` Andy Lutomirski [this message]
2014-01-17 20:08 ` Waiman Long
2014-01-17 21:07 ` Andy Lutomirski
2014-01-10 19:37 ` SIGSEGV when using "perf record -g" with 3.13-rc* kernel Waiman Long
2014-01-10 20:10 ` Peter Zijlstra
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