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: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.343312938@infradead.org
This commit is contained in:
Peter Zijlstra 2022-03-08 16:30:14 +01:00
parent f2d3a25089
commit 1ffbe4e935

View File

@ -3115,9 +3115,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
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);
}
@ -3164,9 +3163,8 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
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);
}
@ -3337,7 +3335,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
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;
/*