On Wed, Feb 07, 2024 at 01:45:28AM +0000, Justin Stitt wrote: > I wouldn't mind also seeing a test_ubsan_div_overflow test case here. > > It has some quirky behavior and it'd be nice to test that the sanitizers > properly capture it. > > Check out this Godbolt: https://godbolt.org/z/qG5f1j6n1 > > tl;dr: with -fsanitize=signed-integer-overflow division (/) and > remainder (%) operators still instrument arithmetic even with > -fno-strict-overflow on. > > This makes sense as division by 0 and INT_MIN/-1 are UBs that are not > influenced by -fno-strict-overflow. There is actually already a test_ubsan_divrem_overflow, but because the failure modes result in a trap even without the sanitizer, it's disabled in the test. For testing a crashing mode, it might be interesting to add it to LKDTM, which is the crash tester... > > Really though, the patch is fine and the above test case is optional and > can be shipped later -- as such: > > Reviewed-by: Justin Stitt <justinstitt@xxxxxxxxxx> Thanks! -Kees -- Kees Cook
