Commit fe0640eb authored Oct 15, 2018 by ndesaulniers@google.com Committed by Miguel Ojeda Oct 19, 2018

compiler.h: update definition of unreachable()

Fixes the objtool warning seen with Clang:
arch/x86/mm/fault.o: warning: objtool: no_context()+0x220: unreachable
instruction

Fixes commit 815f0ddb ("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>

parent f0604f63

include/linux/compiler.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -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

		/*

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