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| author |   Matthew Wilcox <willy@infradead.org> | 2019-01-03 15:26:41 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-01-04 13:13:46 -0800 |
| commit | 3fc2579e6f162fcff964f5aa01c8a29438ca5c05 (patch) | |
| tree | a90c733a19c07e111d9195181d1f3a37e92ef0eb /include/asm-generic/bitops | |
| parent | include/linux/printk.h: drop silly "static inline asmlinkage" from dump_stack() (diff) | |
| download | linux-dev-3fc2579e6f162fcff964f5aa01c8a29438ca5c05.tar.xz linux-dev-3fc2579e6f162fcff964f5aa01c8a29438ca5c05.zip | |
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/asm-generic/bitops')
| -rw-r--r-- | include/asm-generic/bitops/builtin-fls.h | 2 | ||||
| -rw-r--r-- | include/asm-generic/bitops/fls.h | 2 |
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; |