By default, objtool assumes that a UD2 is a dead end. This is mainly because GCC 7+ sometimes inserts a UD2 when it detects a divide-by-zero condition.
Now that WARN() is moving back to UD2, annotate the code after it as reachable so objtool can follow the code flow. Reported-by: Borislav Petkov <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> --- arch/x86/include/asm/bug.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index f2da5fc90e5c..697d89d6fa76 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -74,7 +74,11 @@ do { \ unreachable(); \ } while (0) -#define __WARN_FLAGS(flags) _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)) +#define __WARN_FLAGS(flags) \ +do { \ + _BUG_FLAGS(ASM_UD2, BUGFLAG_WARNING|(flags)); \ + annotate_reachable(); \ +} while (0) #include <asm-generic/bug.h> -- 2.14.3
