| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.1 222/267] compiler-intel: fix wrong compiler barrier() macro | Date | Fri, 31 Jul 2015 12:41:13 -0700 |
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4.1-stable review patch. If anyone has any objections, please let me know.
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From: Daniel Borkmann <daniel@iogearbox.net>
commit b86a50c3b5414eafdbee7f34af4a201a4a7817c2 upstream.
Cleanup commit 73679e508201 ("compiler-intel.h: Remove duplicate definition") removed the double definition of __memory_barrier() intrinsics.
However, in doing so, it also removed the preceding #undef barrier by accident, meaning, the actual barrier() macro from compiler-gcc.h with inline asm is still in place as __GNUC__ is provided.
Subsequently, barrier() can never be defined as __memory_barrier() from compiler.h since it already has a definition in place and if we trust the comment in compiler-intel.h, ecc doesn't support gcc specific asm statements.
I don't have an ecc at hand (unsure if that's still used in the field?) and only found this by accident during code review, a revert of that cleanup would be simplest option.
Fixes: 73679e508201 ("compiler-intel.h: Remove duplicate definition") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: mancha security <mancha1@zoho.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- include/linux/compiler-intel.h | 2 ++ 1 file changed, 2 insertions(+)
--- a/include/linux/compiler-intel.h +++ b/include/linux/compiler-intel.h @@ -13,10 +13,12 @@ /* Intel ECC compiler doesn't support gcc specific asm stmts. * It uses intrinsics to do the equivalent things. */ +#undef barrier #undef barrier_data #undef RELOC_HIDE #undef OPTIMIZER_HIDE_VAR +#define barrier() __memory_barrier() #define barrier_data(ptr) barrier() #define RELOC_HIDE(ptr, off) \
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