Commit 3724062c authored by Josh Poimboeuf's avatar Josh Poimboeuf Committed by Peter Zijlstra
Browse files

objtool: Ignore dangling jump table entries 

Clang sometimes leaves dangling unused jump table entries which point to
the end of the function.  Ignore them.

Closes: https://lore.kernel.org/20250113235835.vqgvb7cdspksy5dn@jpoimboe


Reported-by: default avatarKlaus Kusche <klaus.kusche@computerix.info>
Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/ee25c0b7e80113e950bd1d4c208b671d35774ff4.1736891751.git.jpoimboe@kernel.org
parent 2014c95a

tools/objtool/check.c

+9 −0
Original line number Diff line number Diff line
@@ -1975,6 +1975,14 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, 
		    reloc_addend(reloc) == pfunc->offset)

			break;



		/*

		 * Clang sometimes leaves dangling unused jump table entries

		 * which point to the end of the function.  Ignore them.

		 */

		if (reloc->sym->sec == pfunc->sec &&

		    reloc_addend(reloc) == pfunc->offset + pfunc->len)

			goto next;



		dest_insn = find_insn(file, reloc->sym->sec, reloc_addend(reloc));

		if (!dest_insn)

			break;
@@ -1992,6 +2000,7 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn, 
		alt->insn = dest_insn;

		alt->next = insn->alts;

		insn->alts = alt;

next:

		prev_offset = reloc_offset(reloc);

	}