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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/x86/include/asm/bitops.h
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/x86/include/asm/bitops.h')
-rw-r--r--arch/x86/include/asm/bitops.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 124f9195eb3e..ad7b210aa3f6 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -448,7 +448,7 @@ static __always_inline int ffs(int x)
* set bit if value is nonzero. The last (most significant) bit is
* at position 32.
*/
-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
int r;

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