diff options
| author | Michael Ellerman <mpe@ellerman.id.au> | 2017-01-24 16:36:57 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-02-09 08:08:27 +0100 |
| commit | 8f415333be3a448d9db57a9142fde7efe863432d (patch) | |
| tree | b34d6fe6a56d48ab7f5058062922725a4cf07442 | |
| parent | bbf69e5197daf5560fa37894e50d943b2065496c (diff) | |
powerpc: Fix build failure with clang due to BUILD_BUG_ON()
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@samba.org>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/include/asm/cpu_has_feature.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/mmu.h | 2 |
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cpu_has_feature.h b/arch/powerpc/include/asm/cpu_has_feature.h index b312b152461b..6e834caa3720 100644 --- 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_feature(unsigned long feature) { 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) { diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h index e311c25751a4..a244e09d2d88 100644 --- a/arch/powerpc/include/asm/mmu.h +++ b/arch/powerpc/include/asm/mmu.h @@ -160,7 +160,9 @@ static __always_inline bool mmu_has_feature(unsigned long feature) { 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) { |