linux-kernel - Re: irq 16: nobody cared

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 22 Apr 2013 10:32:17 +0200
From:	Takashi Iwai <tiwai@...e.de>
To:	Borislav Petkov <bp@...en8.de>, x86-ml <x86@...nel.org>,
	lkml <linux-kernel@...r.kernel.org>
Subject: Re: irq 16: nobody cared

At Sun, 21 Apr 2013 09:30:02 -0700,
Paul E. McKenney wrote:
> 
> On Sun, Apr 21, 2013 at 12:34:03PM +0200, Borislav Petkov wrote:
> > On Sat, Apr 20, 2013 at 04:52:07PM -0700, Paul E. McKenney wrote:
> > > Hmmm... Does this problem occur only with CONFIG_RCU_FAST_NO_HZ=y, or
> > > does it occur unconditionally? (My guess is the former, but figured I
> > > should check.)
> > 
> > Your guess is correct, sir.
> > 
> > >From quickly grepping in /boot/, I have CONFIG_RCU_FAST_NO_HZ=y in all
> > my 3.9 configs. So I went and turned it off and the issue doesn't appear
> > anymore.
> 
> Thank you for the info!  Now to figure out what the heck is causing this.
> 
> I am also guessing that your system does have hardware that could do an
> irq 16.  Of course, if removing or disabing this hardware is an option,
> it would be interesting to see what happens.  Especially given that at the
> very bottom of the .jpg, there is a chopped-off line that appears to read
> "Disabling IRQ #16".  Which of course leads me to wonder whether we hit
> a race between the last interrupt arriving and the device being disabled.
> 
> Hmmm...  Do you have either CONFIG_PM_SLEEP, SUPPORT_VGA_SWITCHEROO,
> or CONFIG_PM_RUNTIME set for these runs?
> 
> Adding Takashi Iwai on CC in case he has any insight.

Hm, if it's really due to a stray irq, just adding the missing
synchronize_irq() like below would help?


Takashi

---
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 7b213d5..262dbf1 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -2682,6 +2682,8 @@ static void azx_stop_chip(struct azx *chip)
 	/* disable interrupts */
 	azx_int_disable(chip);
 	azx_int_clear(chip);
+	if (chip->irq >= 0)
+		synchronize_irq(chip->irq);
 
 	/* disable CORB/RIRB */
 	azx_free_cmd_io(chip);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/