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=ham 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 512E2C49ED7 for ; Thu, 19 Sep 2019 22:09:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FEB02196F for ; Thu, 19 Sep 2019 22:09:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568930958; bh=jHeOX+JGSjeo8/ClvRymMzd+5AAANs5t135kcyVXqk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XmZWZzCRQ6YO4kJ5sNiFOAb59bo5S4UZVoGLEmIBRrbTa9i5LpKW9sxiaw+uOgjjQ qCZpDNkwhIyiE3WzwUY+ojlitK3CaQMEW9DJLZequLcSRCFJl6KovGZ7eNsc/ilXOf Bbc07nB3hGVC1CFIW5JCvhPQXaqZ8sChwAr337o0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405385AbfISWJR (ORCPT ); Thu, 19 Sep 2019 18:09:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:47360 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405365AbfISWJN (ORCPT ); Thu, 19 Sep 2019 18:09:13 -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 8402121907; Thu, 19 Sep 2019 22:09:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568930953; bh=jHeOX+JGSjeo8/ClvRymMzd+5AAANs5t135kcyVXqk8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vGcRxIpncc/9/fYrWZ5vbDwv2mEu8X/5hHsx4Wb+0+utDhQeNWGD7X51a64ECRMVk bVONfkDpCZEfY64Js8p+FHWXuGjU4NgCj0fr7ltkYxClNFivwb9N0iE+zGNkq9pOqn rcV6dG8X4E8wkCi+LQC6bALb6KHBBytaRPVUOzmg= 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 5.2 043/124] s390/bpf: use 32-bit index for tail calls Date: Fri, 20 Sep 2019 00:02:11 +0200 Message-Id: <20190919214820.572419274@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190919214819.198419517@linuxfoundation.org> References: <20190919214819.198419517@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 9a711472cbdc0..fd9844f947f79 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1027,8 +1027,8 @@ 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); /* @@ -1054,8 +1054,10 @@ 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