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 5FCB11171A for ; Mon, 21 Aug 2023 20:05:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6FBBC433C9; Mon, 21 Aug 2023 20:05:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1692648343; bh=4nD8u9nNpJpZ5wAZW7xX1mvhw11J97gYxsm1YDatnJk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kv8hf0UY/1JCC3px44iOapS7MgNKEchdK4a9zyEIXvA90+hxcNSoBD8WiCif1Owcg 3As2aKvK2LALVJoqYWfKuG0liIsEwYDKynwMjxtOOcwdC7ZupqTP/mNCgB4F1fmb3V 179wAk/ap3HwvKHLHCumUk7QhSRBF8zpVZ/s++74= 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 6.4 124/234] objtool/x86: Fixup frame-pointer vs rethunk Date: Mon, 21 Aug 2023 21:41:27 +0200 Message-ID: <20230821194134.308191977@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230821194128.754601642@linuxfoundation.org> References: <20230821194128.754601642@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 @@ -2698,12 +2698,17 @@ 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) && - insn_call_dest(insn)->fentry) - return true; + if (insn->type == INSN_CALL) { + struct symbol *dest = insn_call_dest(insn); + + if (!dest) + return false; + + if (dest->fentry || dest->embedded_insn) + return true; + } return false; } @@ -3701,7 +3706,7 @@ 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_INSN(insn, "call without frame pointer save/setup"); return 1;