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| author | Nathan Chancellor <nathan@kernel.org> | 2021-05-28 11:27:52 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-19 09:44:56 +0200 |
| commit | a024e88f8ab79a7b7e15337096d4f5f77edc6a49 (patch) | |
| tree | ec2b7afe6156ad3fa4681a78daf01a19be09afc9 | |
| parent | d2e52d4664097a6c1f591d869ec594bd7a0d4925 (diff) | |
| download | linux-stable-rc-a024e88f8ab79a7b7e15337096d4f5f77edc6a49.tar.gz | |
powerpc/barrier: Avoid collision with clang's __lwsync macro
commit 015d98149b326e0f1f02e44413112ca8b4330543 upstream.
A change in clang 13 results in the __lwsync macro being defined as
__builtin_ppc_lwsync, which emits 'lwsync' or 'msync' depending on what
the target supports. This breaks the build because of -Werror in
arch/powerpc, along with thousands of warnings:
In file included from arch/powerpc/kernel/pmc.c:12:
In file included from include/linux/bug.h:5:
In file included from arch/powerpc/include/asm/bug.h:109:
In file included from include/asm-generic/bug.h:20:
In file included from include/linux/kernel.h:12:
In file included from include/linux/bitops.h:32:
In file included from arch/powerpc/include/asm/bitops.h:62:
arch/powerpc/include/asm/barrier.h:49:9: error: '__lwsync' macro redefined [-Werror,-Wmacro-redefined]
#define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory")
^
<built-in>:308:9: note: previous definition is here
#define __lwsync __builtin_ppc_lwsync
^
1 error generated.
Undefine this macro so that the runtime patching introduced by
commit 2d1b2027626d ("powerpc: Fixup lwsync at runtime") continues to
work properly with clang and the build no longer breaks.
Cc: stable@vger.kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/1386
Link: https://github.com/llvm/llvm-project/commit/62b5df7fe2b3fda1772befeda15598fbef96a614
Link: https://lore.kernel.org/r/20210528182752.1852002-1-nathan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/powerpc/include/asm/barrier.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h index f53c423808327..8c14f84a8770b 100644 --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -46,6 +46,8 @@ # define SMPWMB eieio #endif +/* clang defines this macro for a builtin, which will not work with runtime patching */ +#undef __lwsync #define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") #define dma_rmb() __lwsync() #define dma_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory") |