From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4E7EC49ED7 for ; Thu, 19 Sep 2019 22:30:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7AF2620678 for ; Thu, 19 Sep 2019 22:30:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568932238; bh=MDQ7rLMjvv0P66wPoli3ZPds3gzwj7sGjeX3LmqqTIo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fwcAyZEdLwnnHO3UBjLC4M1VLBqlqrHkGR1nw4vmrWUliPPkck+IBcAmkJj6z0xCa /jykPBa/ZX0lh/+hwHcysAKGWjf1BO0EyTNpw644im5WzaHmTOWQLxSQdAc31HxccI ItWkKSXLhawHIuMeWLjsSLhCi4jEoxaW1h6LHj0Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406253AbfISWQD (ORCPT ); Thu, 19 Sep 2019 18:16:03 -0400 Received: from mail.kernel.org ([198.145.29.99]:56176 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406249AbfISWQD (ORCPT ); Thu, 19 Sep 2019 18:16:03 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B15FE217D6; Thu, 19 Sep 2019 22:16:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568931362; bh=MDQ7rLMjvv0P66wPoli3ZPds3gzwj7sGjeX3LmqqTIo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W+KAwkVEjVyPZq2dg/tdcOA31pKRLT0Z7wEsgXJ3Nk2xjSO2WEJBrg36DPkWFAbBs 3zimrnPrP5nH7evDpr2Tp11N1R2P4kJljHx/odHE3ItLSRQS7gH1+HsyU+gR88CCub KaJNGamk1FrOL7v4XIH9ibMW4PZx8qpccM/1wOkM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yauheni Kaliuta , Vasily Gorbik , Ilya Leoshkevich , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.14 19/59] s390/bpf: use 32-bit index for tail calls Date: Fri, 20 Sep 2019 00:03:34 +0200 Message-Id: <20190919214801.315715000@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190919214755.852282682@linuxfoundation.org> References: <20190919214755.852282682@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ilya Leoshkevich [ Upstream commit 91b4db5313a2c793aabc2143efb8ed0cf0fdd097 ] "p runtime/jit: pass > 32bit index to tail_call" fails when bpf_jit_enable=1, because the tail call is not executed. This in turn is because the generated code assumes index is 64-bit, while it must be 32-bit, and as a result prog array bounds check fails, while it should pass. Even if bounds check would have passed, the code that follows uses 64-bit index to compute prog array offset. Fix by using clrj instead of clgrj for comparing index with array size, and also by using llgfr for truncating index to 32 bits before using it to compute prog array offset. Fixes: 6651ee070b31 ("s390/bpf: implement bpf_tail_call() helper") Reported-by: Yauheni Kaliuta Acked-by: Vasily Gorbik Signed-off-by: Ilya Leoshkevich Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- arch/s390/net/bpf_jit_comp.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index fcb9e840727cd..b8bd841048434 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1063,8 +1063,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i /* llgf %w1,map.max_entries(%b2) */ EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2, offsetof(struct bpf_array, map.max_entries)); - /* clgrj %b3,%w1,0xa,label0: if %b3 >= %w1 goto out */ - EMIT6_PCREL_LABEL(0xec000000, 0x0065, BPF_REG_3, + /* clrj %b3,%w1,0xa,label0: if (u32)%b3 >= (u32)%w1 goto out */ + EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3, REG_W1, 0, 0xa); /* @@ -1090,8 +1090,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i * goto out; */ - /* sllg %r1,%b3,3: %r1 = index * 8 */ - EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3); + /* llgfr %r1,%b3: %r1 = (u32) index */ + EMIT4(0xb9160000, REG_1, BPF_REG_3); + /* sllg %r1,%r1,3: %r1 *= 8 */ + EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3); /* lg %r1,prog(%b2,%r1) */ EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2, REG_1, offsetof(struct bpf_array, ptrs)); -- 2.20.1