From: David Miller <davem@davemloft.net>
To: isubramanian@apm.com
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, mlangsdo@redhat.com,
patches@apm.com, eric.dumazet@gmail.com, kchudgar@apm.com
Subject: Re: [PATCH v2] drivers: net: xgene: fix: Out of order descriptor bytes read
Date: Fri, 30 Jan 2015 18:24:53 -0800 (PST) [thread overview]
Message-ID: <20150130.182453.1030337100939592336.davem@davemloft.net> (raw)
In-Reply-To: <1422571103-17497-1-git-send-email-isubramanian@apm.com>
From: Iyappan Subramanian <isubramanian@apm.com>
Date: Thu, 29 Jan 2015 14:38:23 -0800
> This patch fixes the following kernel crash,
...
> Software writes poison data into the descriptor bytes[15:8] and upon
> receiving the interrupt, if those bytes are overwritten by the hardware with
> the valid data, software also reads bytes[7:0] and executes receive/tx
> completion logic.
>
> If the CPU executes the above two reads in out of order fashion, then the
> bytes[7:0] will have older data and causing the kernel panic. We have to
> force the order of the reads and thus this patch introduces read memory
> barrier between these reads.
>
> Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
> Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Applied, thanks.
prev parent reply other threads:[~2015-01-31 2:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-29 22:38 [PATCH v2] drivers: net: xgene: fix: Out of order descriptor bytes read Iyappan Subramanian
2015-01-31 2:24 ` David Miller [this message]
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