Commit 1ffbe4e9 authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

objtool: Default ignore INT3 for unreachable 



Ignore all INT3 instructions for unreachable code warnings, similar to NOP.
This allows using INT3 for various paddings instead of NOPs.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.343312938@infradead.org
parent f2d3a250

tools/objtool/check.c

+5 −7
Original line number Original line Diff line number Diff line
@@ -3115,9 +3115,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, 
		switch (insn->type) {

		switch (insn->type) {





		case INSN_RETURN:

		case INSN_RETURN:

			if (next_insn && next_insn->type == INSN_TRAP) {

			if (sls && !insn->retpoline_safe &&

				next_insn->ignore = true;

			    next_insn && next_insn->type != INSN_TRAP) {

			} else if (sls && !insn->retpoline_safe) {

				WARN_FUNC("missing int3 after ret",

				WARN_FUNC("missing int3 after ret",

					  insn->sec, insn->offset);

					  insn->sec, insn->offset);

			}

			}
@@ -3164,9 +3163,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, 
			break;

			break;





		case INSN_JUMP_DYNAMIC:

		case INSN_JUMP_DYNAMIC:

			if (next_insn && next_insn->type == INSN_TRAP) {

			if (sls && !insn->retpoline_safe &&

				next_insn->ignore = true;

			    next_insn && next_insn->type != INSN_TRAP) {

			} else if (sls && !insn->retpoline_safe) {

				WARN_FUNC("missing int3 after indirect jump",

				WARN_FUNC("missing int3 after indirect jump",

					  insn->sec, insn->offset);

					  insn->sec, insn->offset);

			}

			}
@@ -3337,7 +3335,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio 
	int i;

	int i;

	struct instruction *prev_insn;

	struct instruction *prev_insn;





	if (insn->ignore || insn->type == INSN_NOP)

	if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP)

		return true;

		return true;





	/*

	/*