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From: Benjamin LaHaise <bcrl@kvack.org>
To: "Elliott, Robert (Server Storage)" <Elliott@hp.com>
Cc: Dan Aloni <dan@kernelim.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	"security@kernel.org" <security@kernel.org>,
	"linux-aio@kvack.org" <linux-aio@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Mateusz Guzik <mguzik@redhat.com>,
	Petr Matousek <pmatouse@redhat.com>,
	Kent Overstreet <kmo@daterainc.com>,
	Jeff Moyer <jmoyer@redhat.com>,
	"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: Revert "aio: fix aio request leak when events are reaped by user space"
Date: Mon, 25 Aug 2014 11:11:56 -0400	[thread overview]
Message-ID: <20140825151156.GE20070@kvack.org> (raw)
In-Reply-To: <94D0CD8314A33A4D9D801C0FE68B402958C22133@G9W0745.americas.hpqcorp.net>

On Mon, Aug 25, 2014 at 03:06:12PM +0000, Elliott, Robert (Server Storage) wrote:
> Using this version of the patch, I ran into this crash after 36
> hours of scsi-mq testing over the weekend.
...
> 
>         local_irq_save(flags);
>         kcpu = this_cpu_ptr(ctx->cpu);
>         kcpu->reqs_available += nr;
> 
>         while (kcpu->reqs_available >= ctx->req_batch * 2) {

This crash is not particularly useful, as that version of the patch was 
buggy and could result in reqs_available getting corrupted (ie, it could 
overflow), which could lead to the system getting stuck for a significant 
amount of time in put_reqs_available().  In other words, the crash you 
reported matches the known problem with that patch.

		-ben
-- 
"Thought is the essence of where you are now."

  reply	other threads:[~2014-08-25 15:11 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-24 18:01 [PATCH 0/2] aio: fixes for kernel memory disclosure in aio read events Benjamin LaHaise
2014-06-24 18:01 ` [PATCH 1/2] aio: fix aio request leak when events are reaped by userspace Benjamin LaHaise
2014-06-24 18:20   ` Jeff Moyer
2014-08-19 16:37   ` Revert "aio: fix aio request leak when events are reaped by user space" Dan Aloni
2014-08-19 16:54     ` Benjamin LaHaise
2014-08-19 17:14       ` Dan Aloni
2014-08-20  0:46         ` Benjamin LaHaise
2014-08-22 16:01           ` Benjamin LaHaise
2014-08-22 16:15             ` Dan Aloni
2014-08-22 16:26               ` Benjamin LaHaise
2014-08-22 18:51                 ` Dan Aloni
2014-08-22 21:43                   ` Linus Torvalds
2014-08-24 18:11                     ` Benjamin LaHaise
2014-08-26  1:11                     ` Kent Overstreet
2014-08-24 18:05                   ` Benjamin LaHaise
2014-08-24 18:48                     ` Dan Aloni
2014-08-27 20:26                       ` Jeff Moyer
2014-08-25 15:06                 ` Elliott, Robert (Server Storage)
2014-08-25 15:11                   ` Benjamin LaHaise [this message]
2014-06-24 18:02 ` [PATCH 2/2] aio: fix kernel memory disclosure in io_getevents() introduced in v3.10 Benjamin LaHaise
2014-06-24 18:23   ` Jeff Moyer
2014-06-24 18:39     ` Benjamin LaHaise
2014-06-24 19:21       ` Jeff Moyer

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