[PATCH] include/linux/log2.h: mark is_power_of_2() with __always_inline

From: Su Hui
Date: Fri Feb 21 2025 - 02:18:40 EST


When build kernel with randconfig, there is an error:

In function ‘kvm_is_cr4_bit_set’,inlined from
‘kvm_update_cpuid_runtime’ at arch/x86/kvm/cpuid.c:310:9:

include/linux/compiler_types.h:542:38: error: call to
‘__compiletime_assert_380’ declared with attribute error:
BUILD_BUG_ON failed: !is_power_of_2(cr4_bit).

'!is_power_of_2(X86_CR4_OSXSAVE)' is False, but gcc treats is_power_of_2()
as non-inline function and a compilation error happens. Fix this by marking
is_power_of_2() with __always_inline.

Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
---
include/linux/log2.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/log2.h b/include/linux/log2.h
index 9f30d087a128..1366cb688a6d 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -41,7 +41,7 @@ int __ilog2_u64(u64 n)
* *not* considered a power of two.
* Return: true if @n is a power of 2, otherwise false.
*/
-static inline __attribute__((const))
+static __always_inline __attribute__((const))
bool is_power_of_2(unsigned long n)
{
return (n != 0 && ((n & (n - 1)) == 0));
--
2.30.2