4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Ellerman <mpe@xxxxxxxxxxxxxx> commit b5fa0f7f88edcde37df1807fdf9ff10ec787a60e upstream. Anton says: In commit 4db7327194db ("powerpc: Add option to use jump label for cpu_has_feature()") and commit c12e6f24d413 ("powerpc: Add option to use jump label for mmu_has_feature()") we added: BUILD_BUG_ON(!__builtin_constant_p(feature)) to cpu_has_feature() and mmu_has_feature() in order to catch usage issues (such as cpu_has_feature(cpu_has_feature(X), which has happened once in the past). Unfortunately LLVM isn't smart enough to resolve this, and it errors out. I work around it in my clang/LLVM builds of the kernel, but I have just discovered that it causes a lot of issues for the bcc (eBPF) trace tool (which uses LLVM). For now just #ifdef it away for clang builds. Fixes: 4db7327194db ("powerpc: Add option to use jump label for cpu_has_feature()") Fixes: c12e6f24d413 ("powerpc: Add option to use jump label for mmu_has_feature()") Reported-by: Anton Blanchard <anton@xxxxxxxxx> Tested-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/include/asm/cpu_has_feature.h | 2 ++ arch/powerpc/include/asm/mmu.h | 2 ++ 2 files changed, 4 insertions(+) --- a/arch/powerpc/include/asm/cpu_has_feature.h +++ b/arch/powerpc/include/asm/cpu_has_feature.h @@ -23,7 +23,9 @@ static __always_inline bool cpu_has_feat { int i; +#ifndef __clang__ /* clang can't cope with this */ BUILD_BUG_ON(!__builtin_constant_p(feature)); +#endif #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG if (!static_key_initialized) { --- a/arch/powerpc/include/asm/mmu.h +++ b/arch/powerpc/include/asm/mmu.h @@ -160,7 +160,9 @@ static __always_inline bool mmu_has_feat { int i; +#ifndef __clang__ /* clang can't cope with this */ BUILD_BUG_ON(!__builtin_constant_p(feature)); +#endif #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG if (!static_key_initialized) { -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html