Re: [PATCH 19/22] block: DAC960: shut up format-overflow warning

From: Jens Axboe
Date: Fri Jul 14 2017 - 10:05:43 EST

On 07/14/2017 06:07 AM, Arnd Bergmann wrote:
> gcc-7 points out that a large controller number would overflow the
> string length for the procfs name and the firmware version string:
> drivers/block/DAC960.c: In function 'DAC960_Probe':
> drivers/block/DAC960.c:6591:38: warning: 'sprintf' may write a terminating nul past the end of the destination [-Wformat-overflow=]
> drivers/block/DAC960.c: In function 'DAC960_V1_ReadControllerConfiguration':
> drivers/block/DAC960.c:1681:40: error: '%02d' directive writing between 2 and 3 bytes into a region of size between 2 and 5 [-Werror=format-overflow=]
> drivers/block/DAC960.c:1681:40: note: directive argument in the range [0, 255]
> drivers/block/DAC960.c:1681:3: note: 'sprintf' output between 10 and 14 bytes into a destination of size 12
> Both of these seem appropriately sized, and using snprintf()
> instead of sprintf() improves this by ensuring that even
> incorrect data won't cause undefined behavior here.

Thanks Arnd, added for 4.14.

Jens Axboe