diff options
| author | Dennis Zhou <dennis@kernel.org> | 2021-02-14 20:16:33 +0300 |
|---|---|---|
| committer | Dennis Zhou <dennis@kernel.org> | 2021-02-14 21:15:15 +0300 |
| commit | 258e0815e2b1706e87c0d874211097aa8a7aa52f (patch) | |
| tree | b98cacd48ddbbdfb81a243053bfd1fbf27d9a5fb /include/linux/compiler_attributes.h | |
| parent | d7d29ac76f7efb506bcecc092641e704f791d92d (diff) | |
| download | linux-258e0815e2b1706e87c0d874211097aa8a7aa52f.tar.xz | |
percpu: fix clang modpost section mismatch
pcpu_build_alloc_info() is an __init function that makes a call to
cpumask_clear_cpu(). With CONFIG_GCOV_PROFILE_ALL enabled, the inline
heuristics are modified and such cpumask_clear_cpu() which is marked
inline doesn't get inlined. Because it works on mask in __initdata,
modpost throws a section mismatch error.
Arnd sent a patch with the flatten attribute as an alternative [2]. I've
added it to compiler_attributes.h.
modpost complaint:
WARNING: modpost: vmlinux.o(.text+0x735425): Section mismatch in reference from the function cpumask_clear_cpu() to the variable .init.data:pcpu_build_alloc_info.mask
The function cpumask_clear_cpu() references
the variable __initdata pcpu_build_alloc_info.mask.
This is often because cpumask_clear_cpu lacks a __initdata
annotation or the annotation of pcpu_build_alloc_info.mask is wrong.
clang output:
mm/percpu.c:2724:5: remark: cpumask_clear_cpu not inlined into pcpu_build_alloc_info because too costly to inline (cost=725, threshold=325) [-Rpass-missed=inline]
[1] https://lore.kernel.org/linux-mm/202012220454.9F6Bkz9q-lkp@intel.com/
[2] https://lore.kernel.org/lkml/CAK8P3a2ZWfNeXKSm8K_SUhhwkor17jFo3xApLXjzfPqX0eUDUA@mail.gmail.com/
Reported-by: kernel test robot <lkp@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Diffstat (limited to 'include/linux/compiler_attributes.h')
| -rw-r--r-- | include/linux/compiler_attributes.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h index ea5e04e75845..c043b8d2b17b 100644 --- a/include/linux/compiler_attributes.h +++ b/include/linux/compiler_attributes.h @@ -211,6 +211,12 @@ #endif /* + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#Common-Function-Attributes + * clang: https://clang.llvm.org/docs/AttributeReference.html#flatten + */ +# define __flatten __attribute__((flatten)) + +/* * Note the missing underscores. * * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-noinline-function-attribute |