linux-kernel - Re: [PATCH v2] Input: evdev - Add EVIOC mechanism to extract the MT slot state

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20120106191835.GA2998@polaris.bitmath.org>
Date:	Fri, 6 Jan 2012 20:18:35 +0100
From:	"Henrik Rydberg" <rydberg@...omail.se>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Benjamin Tissoires <benjamin.tissoires@...il.com>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Chase Douglas <chase.douglas@...onical.com>
Subject: Re: [PATCH v2] Input: evdev - Add EVIOC mechanism to extract the MT
 slot state

On Fri, Jan 06, 2012 at 07:55:44PM +0100, Henrik Rydberg wrote:
> > 2 different processes should be fine; the problem would be if 2 threads
> > of the same process share the same file descriptor. So far the rest of
> > evdev copes just fine with multiple threads using the same fd (all
> > operations are atomic in this regard), setting ABS_MT_SLOT before
> > fetching the state break this property.
> 
> Are we talking about the need for a per-client mutex, or something
> more subtle, like introducing indirect coupling between threads
> through per-client states? The former ought to be easily remedied.

Ok, maybe not to so easy after all, which probably answers my own
question. Looks like a EVIOCGMTSLOT, taking both slot and event code
as argument, would be the cleaner route to take. Another ioctl, how do we
feel about that?

Henrik
--
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/