Hi Kees, On Fri, Sep 09, 2022 at 07:59:05PM +0900, Gwan-gyeong Mun wrote: > From: Kees Cook <keescook@xxxxxxxxxxxx> > > When the check_[op]_overflow() helpers were introduced, all arguments were > required to be the same type to make the fallback macros simpler. However, > now that the fallback macros have been removed[1], it is fine to allow > mixed types, which makes using the helpers much more useful, as they > can be used to test for type-based overflows (e.g. adding two large ints > but storing into a u8), as would be handy in the drm core[2]. > > Remove the restriction, and add additional self-tests that exercise some > of the mixed-type overflow cases, and double-check for accidental macro > side-effects. I would split in two different patches the check_[op]_overflow() helpers with the tests. Overall they look good though. > [1] https://git.kernel.org/linus/4eb6bd55cfb22ffc20652732340c4962f3ac9a91 > [2] https://lore.kernel.org/lkml/20220824084514.2261614-2-gwan-gyeong.mun@xxxxxxxxx > > Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> > Cc: Gwan-gyeong Mun <gwan-gyeong.mun@xxxxxxxxx> > Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx> > Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> > Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > Cc: linux-hardening@xxxxxxxxxxxxxxx > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Gwan-gyeong, can you please add your SoB here? And you don't need to 'Cc:' yourself. Andi
