Thread (6 messages) 6 messages, 3 authors, 2016-11-17

[PATCH] pinctrl: sunxi: fix theoretical uninitialized variable access

From: Maxime Ripard <hidden>
Date: 2016-11-17 09:28:49
Also in: linux-gpio, lkml

On Thu, Nov 17, 2016 at 10:08:28AM +0100, Linus Walleij wrote:
On Wed, Nov 16, 2016 at 9:33 PM, Maxime Ripard
[off-list ref] wrote:
quoted
On Wed, Nov 16, 2016 at 03:18:18PM +0100, Arnd Bergmann wrote:
quoted
gcc warns about a  way that it could use an uninitialized variable:

drivers/pinctrl/sunxi/pinctrl-sunxi.c: In function 'sunxi_pinctrl_init':
drivers/pinctrl/sunxi/pinctrl-sunxi.c:1191:8: error: 'best_div' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This cannot really happen except if 'freq' is UINT_MAX and 'clock' is
zero, and both of these are forbidden. To shut up the warning anyway,
this changes the logic to initialize the return code to the first
divider value before looking at the others.

Fixes: 7c926492d38a ("pinctrl: sunxi: Add support for interrupt debouncing")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Thanks for that patch.

Just out of curiosity, which gcc gives those warnings? I have 6.2 and
it didn't output anything..
Context: Arnd re-enabled -Werror=maybe-uninitialized
in the kernel build and this kind of stuff started to appear so
it needs to be fixed up.
Ah, that makes sense. Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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