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 for <linuxppc-dev@lists.ozlabs.org>; Sat, 24 Oct 2015 00:41:40 +1100 (AEDT)
Subject: Re: [PATCH v6 20/37] cxlflash: Fix to prevent workq from accessing
 freed memory
To: "Matthew R. Ochs" <mrochs@linux.vnet.ibm.com>, linux-scsi@vger.kernel.org,
 James Bottomley <James.Bottomley@HansenPartnership.com>,
 "Nicholas A. Bellinger" <nab@linux-iscsi.org>,
 Brian King <brking@linux.vnet.ibm.com>, Ian Munsie <imunsie@au1.ibm.com>,
 Daniel Axtens <dja@ozlabs.au.ibm.com>,
 Andrew Donnellan <andrew.donnellan@au1.ibm.com>,
 David Laight <David.Laight@ACULAB.COM>
References: <1445458134-63197-1-git-send-email-mrochs@linux.vnet.ibm.com>
 <1445458457-31539-1-git-send-email-mrochs@linux.vnet.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>,
 "Manoj N. Kumar" <manoj@linux.vnet.ibm.com>, linuxppc-dev@lists.ozlabs.org
From: Tomas Henzl <thenzl@redhat.com>
Message-ID: <562A390F.7040909@redhat.com>
Date: Fri, 23 Oct 2015 15:41:35 +0200
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On 21.10.2015 22:14, Matthew R. Ochs wrote:
> The workq can process work in parallel with a remove event, leading
> to a condition where the workq handler can access freed memory.
>
> To remedy, the workq should be terminated prior to freeing memory. Move
> the termination call earlier in remove and use cancel_work_sync() instead
> of flush_work() as there is not a need to process any scheduled work when
> shutting down.
>
> Signed-off-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
> Signed-off-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
> Reviewed-by: Brian King <brking@linux.vnet.ibm.com>

Reviewed-by: Tomas Henzl <thenzl@redhat.com>

Tomas