4.9-stable review patch. If anyone has any objections, please let me know.
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From: Michael Davidson md@google.com
commit 18d5e6c34a8eda438d5ad8b3b15f42dab01bf05d upstream.
undef memcpy() and friends in boot/string.c so that the functions defined here will have the correct names, otherwise we end up up trying to redefine __builtin_memcpy() etc.
Surprisingly, GCC allows this (and, helpfully, discards the __builtin_ prefix from the function name when compiling it), but clang does not.
Adding these #undef's appears to preserve what I assume was the original intent of the code.
Signed-off-by: Michael Davidson md@google.com Signed-off-by: Matthias Kaehlcke mka@chromium.org Acked-by: H. Peter Anvin hpa@zytor.com Cc: Arnd Bergmann arnd@arndb.de Cc: Bernhard.Rosenkranzer@linaro.org Cc: Greg Hackmann ghackmann@google.com Cc: Kees Cook keescook@chromium.org Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Nick Desaulniers ndesaulniers@google.com Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Link: http://lkml.kernel.org/r/20170724235155.79255-1-mka@chromium.org Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/boot/string.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/arch/x86/boot/string.c +++ b/arch/x86/boot/string.c @@ -16,6 +16,15 @@ #include "ctype.h" #include "string.h"
+/* + * Undef these macros so that the functions that we provide + * here will have the correct names regardless of how string.h + * may have chosen to #define them. + */ +#undef memcpy +#undef memset +#undef memcmp + int memcmp(const void *s1, const void *s2, size_t len) { bool diff;