Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.19 21/57] compiler.h: update definition of unreachable() | Date | Fri, 29 Mar 2019 21:28:14 -0400 |
| |
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 /* -- 2.19.1
| |