Commit fb136219 authored Sep 15, 2020 by Julien Thierry Committed by Josh Poimboeuf Sep 18, 2020

objtool: Ignore unreachable fake jumps

It is possible for alternative code to unconditionally jump out of the
alternative region. In such a case, if a fake jump is added at the end
of the alternative instructions, the fake jump will never be reached.
Since the fake jump is just a mean to make sure code validation does not
go beyond the set of alternatives, reaching it is not a requirement.

Signed-off-by: Julien Thierry <jthierry@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

parent f4f80398

tools/objtool/check.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2648,6 +2648,9 @@ static bool ignore_unreachable_insn(struct instruction *insn)
		!strcmp(insn->sec->name, ".altinstr_aux"))
		return true;

		if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->offset == FAKE_JUMP_OFFSET)
		return true;

		if (!insn->func)
		return false;

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