util: fix fallback SUB_OVERFLOW() macro

This only applies when the compiler doesn't provide the
__builtin_sub_overflow() function (before GCC 5.1).

Fixes problem due to integer promotion in overflow macros when result is
a signed type and the subtrahend is an unsigned type with a low value.

SUB_OVERFLOW() still doesn't handle all combinations of signed and
unsigned types in the parameters.

Fixes: ce0d8e2da340 ("util: add macros for arithmetics with overflow checking")
Acked-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

0 files changed, 0 insertions, 0 deletions