public inbox for linux-arm-kernel@lists.infradead.org
 help / color / mirror / Atom feed
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH -next] ALSA: AACI: fix crash in aaci_size_fifo
Date: Mon, 7 Feb 2011 15:13:13 +0000	[thread overview]
Message-ID: <20110207151313.GA5853@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1297091227-27142-1-git-send-email-marc.zyngier@arm.com>

On Mon, Feb 07, 2011 at 03:07:07PM +0000, Marc Zyngier wrote:
> Commit ad58498 (ALSA: AACI: allow writes to MAINCR to take effect)
> that appeared in next-20110207 added a statement treating the maincr
> value as an address.  This leads to a crash while probing the device:
> 
> Unable to handle kernel NULL pointer dereference at virtual address 00000079
> pgd = c0004000
> [00000079] *pgd=00000000
> Internal error: Oops: 1 [#1] PREEMPT SMP
> last sysfs file:
> Modules linked in:
> CPU: 2    Not tainted  (2.6.38-rc3-next-20110207-00031-g7ed0487 #12)
> PC is at aaci_probe+0x438/0x5bc
> LR is at 0x79
> pc : [<c0385b98>]    lr : [<00000079>]    psr: 60000013
> sp : df83beb0  ip : e08be000  fp : 00000000
> r10: 00000000  r9 : 00000000  r8 : 00000000
> r7 : c048e1c0  r6 : df9a65f8  r5 : c0492840  r4 : 00000200
> r3 : 00000000  r2 : e08be000  r1 : 00000079  r0 : 00000078
> Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
> Control: 10c5387f  Table: 8000406a  DAC: 00000015
> 
> As this is probably only a debug leftover, get rid of the statement altogether.

No.  Reading back from the register makes sure that the write hits the device
before we delay.

  reply	other threads:[~2011-02-07 15:13 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-07 15:07 [PATCH -next] ALSA: AACI: fix crash in aaci_size_fifo Marc Zyngier
2011-02-07 15:13 ` Russell King - ARM Linux [this message]
2011-02-07 15:22   ` Marc Zyngier
2011-02-07 15:24     ` Russell King - ARM Linux

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110207151313.GA5853@n2100.arm.linux.org.uk \
    --to=linux@arm.linux.org.uk \
    --cc=linux-arm-kernel@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox