From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Arnd Bergmann" <arnd@arndb.de>,
linux-arm-kernel@lists.infradead.org,
"Måns Rullgård" <mans@mansr.com>,
"David Laight" <David.Laight@aculab.com>,
netdev@vger.kernel.org, "Jon Masters" <jonathan@jonmasters.org>
Subject: Re: alignment faults in 3.6
Date: Fri, 12 Oct 2012 13:24:02 +0100 [thread overview]
Message-ID: <20121012122402.GI21164@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1350036263.21172.11438.camel@edumazet-glaptop>
On Fri, Oct 12, 2012 at 12:04:23PM +0200, Eric Dumazet wrote:
> On Fri, 2012-10-12 at 10:03 +0100, Russell King - ARM Linux wrote:
>
> > No. It is my understanding that various IP option processing can also
> > cause the alignment fault handler to be invoked, even when the packet is
> > properly aligned, and then there's jffs2/mtd which also relies upon
> > alignment faults being fixed up.
>
> Oh well.
>
> We normally make sure we dont have alignment faults on arches that dont
> have CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS (or a non null NET_IP_ALIGN)
>
> So if you find an offender, please report a bug, because I can guarantee
> you we will _fix_ it.
I think one change I will make to the ARM alignment fixup is to get it
to record the last PC where a misaligned kernel fault occurred, and
report it via our statistics procfs file. That should allow us to
track down where some of these occur.
They aren't anywhere near regular though - looking at the statistics, my
firewall seems to do an average of around 2-3 a day, and a web server
around 7-8 a day.
next prev parent reply other threads:[~2012-10-12 12:24 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <506E1762.3010601@gmail.com>
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[not found] ` <506EEFBB.3060705@gmail.com>
[not found] ` <507619FA.6080001@jonmasters.org>
2012-10-11 2:27 ` alignment faults in 3.6 Måns Rullgård
2012-10-11 2:34 ` Jon Masters
2012-10-11 8:21 ` David Laight
2012-10-11 8:53 ` Russell King - ARM Linux
2012-10-11 9:45 ` Måns Rullgård
2012-10-11 10:00 ` Eric Dumazet
2012-10-11 10:20 ` Måns Rullgård
2012-10-11 10:22 ` Eric Dumazet
2012-10-11 10:32 ` Russell King - ARM Linux
2012-10-11 10:49 ` Eric Dumazet
2012-10-11 10:56 ` Maxime Bizon
2012-10-11 11:28 ` Eric Dumazet
2012-10-11 11:47 ` Maxime Bizon
2012-10-11 11:54 ` Eric Dumazet
2012-10-11 12:00 ` Eric Dumazet
2012-10-11 12:51 ` Maxime Bizon
2012-10-11 12:59 ` Eric Dumazet
2012-10-11 12:28 ` Arnd Bergmann
2012-10-11 12:40 ` Eric Dumazet
2012-10-11 13:20 ` Rob Herring
2012-10-11 13:32 ` Måns Rullgård
2012-10-11 13:35 ` Arnd Bergmann
2012-10-11 13:47 ` Eric Dumazet
2012-10-11 15:23 ` Rob Herring
2012-10-11 15:39 ` David Laight
2012-10-11 16:18 ` Måns Rullgård
2012-10-12 8:11 ` Arnd Bergmann
2012-10-12 9:03 ` Russell King - ARM Linux
2012-10-12 10:04 ` Eric Dumazet
2012-10-12 12:24 ` Russell King - ARM Linux [this message]
2012-10-12 11:00 ` Måns Rullgård
2012-10-12 11:07 ` Russell King - ARM Linux
2012-10-12 11:18 ` Måns Rullgård
2012-10-12 11:44 ` Russell King - ARM Linux
2012-10-12 12:08 ` Eric Dumazet
2012-10-12 14:22 ` Benjamin LaHaise
2012-10-12 14:36 ` David Laight
2012-10-12 14:48 ` Eric Dumazet
2012-10-12 15:00 ` Benjamin LaHaise
2012-10-12 15:04 ` Ben Hutchings
2012-10-12 15:47 ` David Laight
2012-10-12 16:13 ` Ben Hutchings
2012-10-12 12:16 ` Måns Rullgård
2012-10-12 11:19 ` Russell King - ARM Linux
2012-10-11 16:15 ` Eric Dumazet
2012-10-11 16:59 ` Catalin Marinas
2012-10-11 10:16 ` David Laight
2012-10-11 10:46 ` Måns Rullgård
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