path: root/arch/arc
diff options
authorMatthew Wilcox <willy@infradead.org>2019-01-03 15:26:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-01-04 13:13:46 -0800
commit3fc2579e6f162fcff964f5aa01c8a29438ca5c05 (patch)
treea90c733a19c07e111d9195181d1f3a37e92ef0eb /arch/arc
parente6310f0fb5cd3f65244dbdef2fb264859891c7ec (diff)
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 <willy@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arc')
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arc/include/asm/bitops.h b/arch/arc/include/asm/bitops.h
index 8da87feec59a..ee9246184033 100644
--- a/arch/arc/include/asm/bitops.h
+++ b/arch/arc/include/asm/bitops.h
@@ -278,7 +278,7 @@ static inline __attribute__ ((const)) int clz(unsigned int x)
return res;
-static inline int constant_fls(int x)
+static inline int constant_fls(unsigned int x)
int r = 32;
@@ -312,7 +312,7 @@ static inline int constant_fls(int x)
* @result: [1-32]
* fls(1) = 1, fls(0x80000000) = 32, fls(0) = 0
-static inline __attribute__ ((const)) int fls(unsigned long x)
+static inline __attribute__ ((const)) int fls(unsigned int x)
if (__builtin_constant_p(x))
return constant_fls(x);