From: "ndesaulniers@google.com" ndesaulniers@google.com
[ Upstream commit fe0640eb30b7da261ae84d252ed9ed3c7e68dfd8 ]
Fixes the objtool warning seen with Clang: arch/x86/mm/fault.o: warning: objtool: no_context()+0x220: unreachable instruction
Fixes commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")
Josh noted that the fallback definition was meant to work around a pre-gcc-4.6 bug. GCC still needs to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365, so compiler-gcc.h defines its own version of unreachable(). Clang and ICC can use this shared definition.
Link: https://github.com/ClangBuiltLinux/linux/issues/204 Suggested-by: Andy Lutomirski luto@amacapital.net Suggested-by: Josh Poimboeuf jpoimboe@redhat.com Tested-by: Nathan Chancellor natechancellor@gmail.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Miguel Ojeda miguel.ojeda.sandonis@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/compiler.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 269d376f5a11..81c2238b884c 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -124,7 +124,10 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, # define ASM_UNREACHABLE #endif #ifndef unreachable -# define unreachable() do { annotate_reachable(); do { } while (1); } while (0) +# define unreachable() do { \ + annotate_unreachable(); \ + __builtin_unreachable(); \ +} while (0) #endif
/*