releases/4.4.165/x86-boot-undef-memcpy-et-al-in-string.c.patch

   1 From foo@baz Wed Nov 21 18:50:39 CET 2018
   2 From: Michael Davidson <md@google.com>
   3 Date: Mon, 24 Jul 2017 16:51:55 -0700
   4 Subject: x86/boot: #undef memcpy() et al in string.c
   5
   6 From: Michael Davidson <md@google.com>
   7
   8 commit 18d5e6c34a8eda438d5ad8b3b15f42dab01bf05d upstream.
   9
  10 undef memcpy() and friends in boot/string.c so that the functions
  11 defined here will have the correct names, otherwise we end up
  12 up trying to redefine __builtin_memcpy() etc.
  13
  14 Surprisingly, GCC allows this (and, helpfully, discards the
  15 __builtin_ prefix from the function name when compiling it),
  16 but clang does not.
  17
  18 Adding these #undef's appears to preserve what I assume was
  19 the original intent of the code.
  20
  21 Signed-off-by: Michael Davidson <md@google.com>
  22 Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
  23 Acked-by: H. Peter Anvin <hpa@zytor.com>
  24 Cc: Arnd Bergmann <arnd@arndb.de>
  25 Cc: Bernhard.Rosenkranzer@linaro.org
  26 Cc: Greg Hackmann <ghackmann@google.com>
  27 Cc: Kees Cook <keescook@chromium.org>
  28 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  29 Cc: Nick Desaulniers <ndesaulniers@google.com>
  30 Cc: Peter Zijlstra <peterz@infradead.org>
  31 Cc: Thomas Gleixner <tglx@linutronix.de>
  32 Link: http://lkml.kernel.org/r/20170724235155.79255-1-mka@chromium.org
  33 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  34 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
  35 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  36 ---
  37  arch/x86/boot/string.c |    9 +++++++++
  38  1 file changed, 9 insertions(+)
  39
  40 --- a/arch/x86/boot/string.c
  41 +++ b/arch/x86/boot/string.c
  42 @@ -16,6 +16,15 @@
  43  #include "ctype.h"
  44  #include "string.h"
  45
  46 +/*
  47 + * Undef these macros so that the functions that we provide
  48 + * here will have the correct names regardless of how string.h
  49 + * may have chosen to #define them.
  50 + */
  51 +#undef memcpy
  52 +#undef memset
  53 +#undef memcmp
  54 +
  55  int memcmp(const void *s1, const void *s2, size_t len)
  56  {
  57         u8 diff;