linux-kernel - Re: [PATCH] DRM: Armada: fixup wait_event

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]

Message-ID: <20150610112235.GL7557@n2100.arm.linux.org.uk>
Date:	Wed, 10 Jun 2015 12:22:36 +0100
From:	Russell King - ARM Linux <linux@....linux.org.uk>
To:	Nicholas Mc Guire <hofrat@...dl.org>
Cc:	David Airlie <airlied@...ux.ie>, dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] DRM: Armada: fixup wait_event_timeout being ignored

On Wed, Jun 10, 2015 at 01:07:08PM +0200, Nicholas Mc Guire wrote:
> The calling side seems to assume 0 as success and <0 as error so 
> returning -ETIME should be fine here.

The idea here is to allow the remainder of the code to execute when
the condition succeeds _or_ times out.  If it times out, that is
not a failure - it merely means that the display has been blanked
and we're not seeing frame done interrupts anymore.

The code should not be checking the returned value at all - in fact
I have updates to this code which (in part) remove this, and fix a
glaring problem that the wait queue is never woken.

I wonder how many places you've made this same mistake... please
ensure that you review the code you're changing carefully.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
--
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/