fls: change parameter to unsigned int
authorMatthew Wilcox <willy@infradead.org>
Thu, 3 Jan 2019 23:26:41 +0000 (15:26 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 4 Jan 2019 21:13:46 +0000 (13:13 -0800)
commitc744494202d5721504399a1759a8ed04401070a8
treea90c733a19c07e111d9195181d1f3a37e92ef0eb
parente053b9669719ea19b14e6a695baf5f154a9d19d9
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>
16 files changed:
arch/alpha/include/asm/bitops.h
arch/arc/include/asm/bitops.h
arch/c6x/include/asm/bitops.h
arch/csky/include/asm/bitops.h
arch/hexagon/include/asm/bitops.h
arch/ia64/include/asm/bitops.h
arch/m68k/include/asm/bitops.h
arch/mips/include/asm/bitops.h
arch/openrisc/include/asm/bitops/fls.h
arch/parisc/include/asm/bitops.h
arch/s390/include/asm/bitops.h
arch/unicore32/include/asm/bitops.h
arch/x86/include/asm/bitops.h
include/asm-generic/bitops/builtin-fls.h
include/asm-generic/bitops/fls.h
tools/include/asm-generic/bitops/fls.h