From: Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx> Subject: linux/build_bug.h: change type to int Having BUILD_BUG_ON_ZERO produce a value of type size_t leads to awkward casts in cases where the result needs to be signed, or of smaller type than size_t. To avoid this, cast the value to int instead and rely on implicit type conversions when a larger or unsigned type is needed. Link: http://lkml.kernel.org/r/20190811184938.1796-3-rikard.falkeborn@xxxxxxxxx Signed-off-by: Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx> Suggested-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Reviewed-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/build_bug.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/include/linux/build_bug.h~linux-build_bugh-change-type-to-int +++ a/include/linux/build_bug.h @@ -9,11 +9,11 @@ #else /* __CHECKER__ */ /* * Force a compilation error if condition is true, but also produce a - * result (of value 0 and type size_t), so the expression can be used + * result (of value 0 and type int), so the expression can be used * e.g. in a structure initializer (or where-ever else comma expressions * aren't permitted). */ -#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:(-!!(e)); })) +#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); }))) #endif /* __CHECKER__ */ /* Force a compilation error if a constant expression is not a power of 2 */ _
