releases/4.14.113/compiler.h-update-definition-of-unreachable.patch

   1 From 55aa856ef228dac6708a7ca0e8b678d49f47e59a Mon Sep 17 00:00:00 2001
   2 From: "ndesaulniers@google.com" <ndesaulniers@google.com>
   3 Date: Mon, 15 Oct 2018 10:22:21 -0700
   4 Subject: compiler.h: update definition of unreachable()
   5
   6 [ Upstream commit fe0640eb30b7da261ae84d252ed9ed3c7e68dfd8 ]
   7
   8 Fixes the objtool warning seen with Clang:
   9 arch/x86/mm/fault.o: warning: objtool: no_context()+0x220: unreachable
  10 instruction
  11
  12 Fixes commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h
  13 mutually exclusive")
  14
  15 Josh noted that the fallback definition was meant to work around a
  16 pre-gcc-4.6 bug. GCC still needs to work around
  17 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365, so compiler-gcc.h
  18 defines its own version of unreachable().  Clang and ICC can use this
  19 shared definition.
  20
  21 Link: https://github.com/ClangBuiltLinux/linux/issues/204
  22 Suggested-by: Andy Lutomirski <luto@amacapital.net>
  23 Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
  24 Tested-by: Nathan Chancellor <natechancellor@gmail.com>
  25 Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
  26 Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
  27 Signed-off-by: Sasha Levin <sashal@kernel.org>
  28 ---
  29  include/linux/compiler.h | 5 ++++-
  30  1 file changed, 4 insertions(+), 1 deletion(-)
  31
  32 diff --git a/include/linux/compiler.h b/include/linux/compiler.h
  33 index a704d032713b..67c3934fb9ed 100644
  34 --- a/include/linux/compiler.h
  35 +++ b/include/linux/compiler.h
  36 @@ -119,7 +119,10 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
  37  # define ASM_UNREACHABLE
  38  #endif
  39  #ifndef unreachable
  40 -# define unreachable() do { annotate_reachable(); do { } while (1); } while (0)
  41 +# define unreachable() do {            \
  42 +       annotate_unreachable();         \
  43 +       __builtin_unreachable();        \
  44 +} while (0)
  45  #endif
  46
  47  /*
  48 --
  49 2.19.1
  50