[PATCH 6.12 033/242] objtool: Fix Clang jump table detection

Greg Kroah-Hartman
2026-04-08T18:40:45Z

From: Josh Poimboeuf <jpoimboe@kernel.org>

[ Upstream commit 4e5019216402ad0b4a84cff457b662d26803f103 ]

With Clang, there can be a conditional forward jump between the load of
the jump table address and the indirect branch.

Fixes the following warning:

vmlinux.o: warning: objtool: ___bpf_prog_run+0x1c5: sibling call from callable instruction with modified stack frame

Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/a426d669-58bb-4be1-9eaa-6f3d83109e2d@app.fastmail.com
Link: https://patch.msgid.link/7d8600caed08901b6679767488acd639f6df9688.1773071992.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/objtool/check.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index ad83bb3197225..b75ddb3fca0df 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -2174,12 +2174,11 @@ static void mark_func_jump_tables(struct objtool_file *file,
last = insn;

/*
- * Store back-pointers for unconditional forward jumps such
+ * Store back-pointers for forward jumps such
* that find_jump_table() can back-track using those and
* avoid some potentially confusing code.
*/
- if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest &&
- insn->offset > last->offset &&
+ if (insn->jump_dest &&
insn->jump_dest->offset > insn->offset &&
!insn->jump_dest->first_jump_src) {

--
2.53.0