Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH 06/11] tools/kernel.h: add BUILD_BUG_ON_NOT_POWER_OF_2 macro | Date | Mon, 17 Feb 2020 21:41:28 -0500 |
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This is now needed as a result of 12593b7467f9 ("locking/lockdep: Reduce space occupied by stack traces").
Signed-off-by: Sasha Levin <sashal@kernel.org> --- tools/include/linux/kernel.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/tools/include/linux/kernel.h b/tools/include/linux/kernel.h index d2b3e1cc0218e..cc3d60623ca47 100644 --- a/tools/include/linux/kernel.h +++ b/tools/include/linux/kernel.h @@ -38,6 +38,12 @@ #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)])) #define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) +/* Force a compilation error if a constant expression is not a power of 2 */ +#define __BUILD_BUG_ON_NOT_POWER_OF_2(n) \ + BUILD_BUG_ON(((n) & ((n) - 1)) != 0) +#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \ + BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0)) + #ifndef max #define max(x, y) ({ \ typeof(x) _max1 = (x); \ -- 2.20.1
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