From 4099bcd87390c64d6778a17d5495863a11a7b356 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 29 Nov 2024 15:47:49 +0100 Subject: [PATCH] objtool/x86: allow syscall instruction commit dda014ba59331dee4f3b773a020e109932f4bd24 upstream. The syscall instruction is used in Xen PV mode for doing hypercalls. Allow syscall to be used in the kernel in case it is tagged with an unwind hint for objtool. This is part of XSA-466 / CVE-2024-53241. Reported-by: Andrew Cooper Signed-off-by: Juergen Gross Co-developed-by: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman --- tools/objtool/check.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 0506a48f124c2..bcc9948645a00 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3039,10 +3039,13 @@ static int validate_branch(struct objtool_file *file, struct symbol *func, break; case INSN_CONTEXT_SWITCH: - if (func && (!next_insn || !next_insn->hint)) { - WARN_FUNC("unsupported instruction in callable function", - sec, insn->offset); - return 1; + if (func) { + if (!next_insn || !next_insn->hint) { + WARN_FUNC("unsupported instruction in callable function", + sec, insn->offset); + return 1; + } + break; } return 0; -- 2.47.3