From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> commit 1ffbe4e935f9b7308615c75be990aec07464d1e7 upstream. Ignore all INT3 instructions for unreachable code warnings, similar to NOP. This allows using INT3 for various paddings instead of NOPs. Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Acked-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220308154317.343312938@xxxxxxxxxxxxx Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/objtool/check.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2965,9 +2965,8 @@ static int validate_branch(struct objtoo switch (insn->type) { case INSN_RETURN: - if (next_insn && next_insn->type == INSN_TRAP) { - next_insn->ignore = true; - } else if (sls && !insn->retpoline_safe) { + if (sls && !insn->retpoline_safe && + next_insn && next_insn->type != INSN_TRAP) { WARN_FUNC("missing int3 after ret", insn->sec, insn->offset); } @@ -3014,9 +3013,8 @@ static int validate_branch(struct objtoo break; case INSN_JUMP_DYNAMIC: - if (next_insn && next_insn->type == INSN_TRAP) { - next_insn->ignore = true; - } else if (sls && !insn->retpoline_safe) { + if (sls && !insn->retpoline_safe && + next_insn && next_insn->type != INSN_TRAP) { WARN_FUNC("missing int3 after indirect jump", insn->sec, insn->offset); } @@ -3187,7 +3185,7 @@ static bool ignore_unreachable_insn(stru int i; struct instruction *prev_insn; - if (insn->ignore || insn->type == INSN_NOP) + if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP) return true; /*
