[PATCH AUTOSEL 6.6 12/24] objtool: Stop UNRET validation on UD2

From: Sasha Levin
Date: Mon Apr 14 2025 - 09:56:32 EST


From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>

[ Upstream commit 9f9cc012c2cbac4833746a0182e06a8eec940d19 ]

In preparation for simplifying INSN_SYSCALL, make validate_unret()
terminate control flow on UD2 just like validate_branch() already does.

Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/ce841269e7e28c8b7f32064464a9821034d724ff.1744095216.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/objtool/check.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 9102ad5985cc0..78f38a74bd398 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3935,6 +3935,9 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn)
break;
}

+ if (insn->dead_end)
+ return 0;
+
if (!next) {
WARN_INSN(insn, "teh end!");
return -1;
--
2.39.5