linux-kernel - Re: [PATCH 11/19] regmap: avoid undefined return from regmap_read

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: <201301260917.28028.arnd@arndb.de>
Date:	Sat, 26 Jan 2013 09:17:27 +0000
From:	Arnd Bergmann <arnd@...db.de>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	"Greg Kroah-Hartman" <gregkh@...uxfoundation.org>
Subject: Re: [PATCH 11/19] regmap: avoid undefined return from regmap_read_debugfs

On Saturday 26 January 2013, Mark Brown wrote:
> On Fri, Jan 25, 2013 at 02:14:28PM +0000, Arnd Bergmann wrote:
> > Gcc warns about the case where regmap_read_debugfs tries
> 
> Are you sure about that function name?

Yes, regmap_read_debugfs uses the return value from
regmap_debugfs_get_dump_start, for which gcc found
a path that returns the uninitialized value.

> > to walk an empty map->debugfs_off_cache list, which results
> > in uninitialized variable getting returned.
> 
> > Setting this variable to 0 first avoids the warning and
> > the potentially undefined value.
> 
> This probably won't apply against current code as there's already a
> better fix there, in general just picking a value to initialise masks
> errors.

I agree on the general rule not to do this, and I'm trying to avoid it
in the cases where I can find a better fix, but here I could not
(mostly because I could not figure out what this code actually
does. Thanks for taking a look.

Which code is the current version? Is your fix headed for 3.8 inclusion?

I still see the warning in 3.8-rc5 as well as yesterday's linux-next,
with gcc-4.6, 4.7 and 4.8-pre.

	Arnd
--
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/