From 3fc2579e6f162fcff964f5aa01c8a29438ca5c05 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 3 Jan 2019 15:26:41 -0800 Subject: fls: change parameter to unsigned int When testing in userspace, UBSAN pointed out that shifting into the sign bit is undefined behaviour. It doesn't really make sense to ask for the highest set bit of a negative value, so just turn the argument type into an unsigned int. Some architectures (eg ppc) already had it declared as an unsigned int, so I don't expect too many problems. Link: http://lkml.kernel.org/r/20181105221117.31828-1-willy@infradead.org Signed-off-by: Matthew Wilcox Acked-by: Thomas Gleixner Acked-by: Geert Uytterhoeven Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/include/asm/bitops.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/s390') diff --git a/arch/s390/include/asm/bitops.h b/arch/s390/include/asm/bitops.h index 86e5b2fdee3c..d1f8a4d94cca 100644 --- a/arch/s390/include/asm/bitops.h +++ b/arch/s390/include/asm/bitops.h @@ -397,9 +397,9 @@ static inline int fls64(unsigned long word) * This is defined the same way as ffs. * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. */ -static inline int fls(int word) +static inline int fls(unsigned int word) { - return fls64((unsigned int)word); + return fls64(word); } #else /* CONFIG_HAVE_MARCH_Z9_109_FEATURES */ -- cgit v1.2.3-70-g09d2