[PATCH] arm: put_user: fix possible data corruption in put_user

Russell King - ARM Linux linux at arm.linux.org.uk
Mon May 5 02:01:26 PDT 2014


On Mon, May 05, 2014 at 10:13:58AM +0400, Andrey Ryabinin wrote:
> According to arm procedure call standart r2 register is call-cloberred.
> So after the result of x expression was put into r2 any following
> function call in p may overwrite r2. To fix this, the result of p
> expression must be saved to the temporary variable before the
> assigment x expression to __r2.

This and the patch make no sense.  You talk about r2, but you're doing
nothing with r2 in the patch.

-- 
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.



More information about the linux-arm-kernel mailing list