From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 317B6111A8 for ; Thu, 24 Aug 2023 14:15:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A878C433C8; Thu, 24 Aug 2023 14:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1692886537; bh=PSzzHcLbiJRPJ8XMHvqia7Gwh0KcHTTH6tmKWeVToR8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oM9CBqnYWOa6i9nn5BvTA5O9scFSLDDtXq19H8AT+HP2L5pNYlRG7aO7SbF5zAb3k uXE9wRP6xfb+2HCtOPqgphIW1Ag6c0YvpdTVRi97BC8a8b6wXnPo0DXhDMESnFaFoF Uo1Tsmtk/qaUc1AfQaBvTJkNThXDsTN7sBBw3Xow= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Peter Zijlstra (Intel)" , "Borislav Petkov (AMD)" , Josh Poimboeuf Subject: [PATCH 6.1 14/15] objtool/x86: Fixup frame-pointer vs rethunk Date: Thu, 24 Aug 2023 16:15:10 +0200 Message-ID: <20230824141447.814551319@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230824141447.155846739@linuxfoundation.org> References: <20230824141447.155846739@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Peter Zijlstra commit dbf46008775516f7f25c95b7760041c286299783 upstream. For stack-validation of a frame-pointer build, objtool validates that every CALL instruction is preceded by a frame-setup. The new SRSO return thunks violate this with their RSB stuffing trickery. Extend the __fentry__ exception to also cover the embedded_insn case used for this. This cures: vmlinux.o: warning: objtool: srso_untrain_ret+0xd: call without frame pointer save/setup Fixes: 4ae68b26c3ab ("objtool/x86: Fix SRSO mess") Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20230816115921.GH980931@hirez.programming.kicks-ass.net Signed-off-by: Greg Kroah-Hartman --- tools/objtool/check.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2450,12 +2450,17 @@ static int decode_sections(struct objtoo return 0; } -static bool is_fentry_call(struct instruction *insn) +static bool is_special_call(struct instruction *insn) { - if (insn->type == INSN_CALL && - insn->call_dest && - insn->call_dest->fentry) - return true; + if (insn->type == INSN_CALL) { + struct symbol *dest = insn->call_dest; + + if (!dest) + return false; + + if (dest->fentry) + return true; + } return false; } @@ -3448,7 +3453,7 @@ static int validate_branch(struct objtoo if (ret) return ret; - if (opts.stackval && func && !is_fentry_call(insn) && + if (opts.stackval && func && !is_special_call(insn) && !has_valid_stack_frame(&state)) { WARN_FUNC("call without frame pointer save/setup", sec, insn->offset);