summaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
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 /include
parente6310f0fb5cd3f65244dbdef2fb264859891c7ec (diff)
downloadlinux-3fc2579e6f162fcff964f5aa01c8a29438ca5c05.tar.bz2
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 'include')
-rw-r--r--include/asm-generic/bitops/builtin-fls.h2
-rw-r--r--include/asm-generic/bitops/fls.h2
2 files changed, 2 insertions, 2 deletions
diff --git a/include/asm-generic/bitops/builtin-fls.h b/include/asm-generic/bitops/builtin-fls.h
index 62daf940989d..c8455cc28841 100644
--- a/include/asm-generic/bitops/builtin-fls.h
+++ b/include/asm-generic/bitops/builtin-fls.h
@@ -9,7 +9,7 @@
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
}
diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h
index 753aecaab641..b168bb10e1be 100644
--- a/include/asm-generic/bitops/fls.h
+++ b/include/asm-generic/bitops/fls.h
@@ -10,7 +10,7 @@
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
-static __always_inline int fls(int x)
+static __always_inline int fls(unsigned int x)
{
int r = 32;