Commit a64bb02f authored Nov 21, 2014 by Linus Torvalds

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core fix from Ingo Molnar:
 "Fix GENMASK macro shift overflow"

Nobody seems to currently use GENMASK() to fill every single last bit
(which is what overflows) in-tree, and gcc would warn about it, so we
have that going for us.  But apparently there are pending changes that
want this.

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  bitops: Fix shift overflow in GENMASK macros

parents fc14f9c1 00b4d9a1

include/linux/bitops.h

+5 −2

Original line number	Diff line number	Diff line
		@@ -18,8 +18,11 @@
		* position @h. For example
		* GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
		*/
		#define GENMASK(h, l) (((U32_C(1) << ((h) - (l) + 1)) - 1) << (l))
		#define GENMASK_ULL(h, l) (((U64_C(1) << ((h) - (l) + 1)) - 1) << (l))
		#define GENMASK(h, l) \
		(((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h))))

		#define GENMASK_ULL(h, l) \
		(((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))

		extern unsigned int __sw_hweight8(unsigned int w);
		extern unsigned int __sw_hweight16(unsigned int w);

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