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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-11-21 15:38:21 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-11-21 15:38:21 -0800 |
| commit | a64bb02f4a62a604d8dd62decb559b9c6adfb40c (patch) | |
| tree | 56d0f7ba555d5b62e4043464f320baf239c05cbe | |
| parent | fc14f9c1272f62c3e8d01300f52467c0d9af50f9 (diff) | |
| parent | 00b4d9a14125f1e51874def2b9de6092e007412d (diff) | |
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
| -rw-r--r-- | include/linux/bitops.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/bitops.h b/include/linux/bitops.h index be5fd38bd5a0..5d858e02997f 100644 --- a/include/linux/bitops.h +++ b/include/linux/bitops.h @@ -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); |