From: Joerg Roedel <joro@8bytes.org>
To: "Lewycky, Andrew" <Andrew.Lewycky@amd.com>
Cc: Jerome Glisse <j.glisse@gmail.com>,
"Gabbay, Oded" <Oded.Gabbay@amd.com>,
"Deucher, Alexander" <Alexander.Deucher@amd.com>,
"Cornwall, Jay" <Jay.Cornwall@amd.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mgorman@suse.de" <mgorman@suse.de>,
"hpa@zytor.com" <hpa@zytor.com>,
"peterz@infraread.org" <peterz@infraread.org>,
"aarcange@redhat.com" <aarcange@redhat.com>,
"riel@redhat.com" <riel@redhat.com>,
"jweiner@redhat.com" <jweiner@redhat.com>,
"torvalds@linux-foundation.org" <torvalds@linux-foundation.org>,
Mark Hairgrove <mhairgrove@nvidia.com>,
Jatin Kumar <jakumar@nvidia.com>,
Subhash Gutti <sgutti@nvidia.com>,
Lucien Dunning <ldunning@nvidia.com>,
Cameron Buschardt <cabuschardt@nvidia.com>,
Arvind Gopalakrishnan <arvindg@nvidia.com>,
John
Subject: Re: [PATCH 1/6] mmput: use notifier chain to call subsystem exit handler.
Date: Tue, 1 Jul 2014 11:41:41 +0200 [thread overview]
Message-ID: <20140701094141.GG26537@8bytes.org> (raw)
In-Reply-To: <3725846D7614874B8367361CC6008D741645DFA0@storexdag01.amd.com>
Hi Andrew,
On Mon, Jun 30, 2014 at 06:57:48PM +0000, Lewycky, Andrew wrote:
> As an aside we found another small issue: amd_iommu_bind_pasid calls
> get_task_mm. This bumps the mm_struct use count and it will never be
> released. This would prevent the buggy code path described above from
> ever running in the first place.
You are right, the current code is a bit problematic, but to fix this no
new notifier chain in mm-code is needed.
In fact, using get_task_mm() is a good way to keep a reference to the mm
as a user (an external device is in fact another user) and defer the
destruction of the mappings to the file-close path (where you can call
mmput to destroy it). So this is another way to solve the problem
without any new notifier.
Joerg
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next prev parent reply other threads:[~2014-07-01 9:41 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1403920822-14488-1-git-send-email-j.glisse@gmail.com>
[not found] ` <1403920822-14488-2-git-send-email-j.glisse@gmail.com>
2014-06-30 14:41 ` [PATCH 1/6] mmput: use notifier chain to call subsystem exit handler Gabbay, Oded
[not found] ` <019CCE693E457142B37B791721487FD91806B836-0nO7ALo/ziwxlywnonMhLEEOCMrvLtNR@public.gmane.org>
2014-06-30 15:06 ` Jerome Glisse
2014-06-30 15:40 ` Joerg Roedel
2014-06-30 16:06 ` Jerome Glisse
2014-06-30 18:16 ` Joerg Roedel
2014-06-30 18:35 ` Jerome Glisse
2014-06-30 18:57 ` Lewycky, Andrew
2014-07-01 9:41 ` Joerg Roedel [this message]
[not found] ` <20140630183556.GB3280-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-07-01 9:15 ` Joerg Roedel
2014-07-01 9:29 ` Gabbay, Oded
[not found] ` <019CCE693E457142B37B791721487FD91806DD8B-0nO7ALo/ziwxlywnonMhLEEOCMrvLtNR@public.gmane.org>
2014-07-01 11:00 ` Joerg Roedel
2014-07-01 19:33 ` Jerome Glisse
[not found] ` <20140701193343.GB3322-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-07-01 21:06 ` Joerg Roedel
2014-07-01 21:32 ` Jerome Glisse
2014-07-03 18:30 ` Jerome Glisse
[not found] ` <20140703183024.GA3306-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-07-03 23:15 ` Joerg Roedel
2014-07-04 0:03 ` Jerome Glisse
[not found] ` <20140703231541.GR26537-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-07-06 19:25 ` Gabbay, Oded
2014-07-07 10:11 ` joro
2014-07-07 10:36 ` Oded Gabbay
2014-07-07 10:43 ` Oded Gabbay
[not found] ` <1404729783.31606.1.camel-OrheeFI7RUaGvNAqNQFwiPZ4XP/Yx64J@public.gmane.org>
2014-07-08 8:00 ` joro-zLv9SwRftAIdnm+yROfE0A
[not found] ` <20140708080059.GF1958-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
2014-07-08 17:03 ` Jerome Glisse
2015-10-11 19:03 ` David Woodhouse
[not found] ` <1444590209.92154.116.camel-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2015-10-12 17:41 ` Jerome Glisse
2015-11-20 15:45 ` David Woodhouse
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