From patchwork Fri Jul 17 16:53:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 1331343 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B7cjz1stQz9sTF for ; Sat, 18 Jul 2020 02:57:27 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727828AbgGQQ50 (ORCPT ); Fri, 17 Jul 2020 12:57:26 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:37434 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727870AbgGQQ5V (ORCPT ); Fri, 17 Jul 2020 12:57:21 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06HGWh21080245; Fri, 17 Jul 2020 12:57:09 -0400 Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0b-001b2d01.pphosted.com with ESMTP id 32ax79473g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Jul 2020 12:57:09 -0400 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 06HGnf6X027378; Fri, 17 Jul 2020 16:57:07 GMT Received: from b06cxnps4075.portsmouth.uk.ibm.com (d06relay12.portsmouth.uk.ibm.com [9.149.109.197]) by ppma02fra.de.ibm.com with ESMTP id 327527y40h-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 17 Jul 2020 16:57:07 +0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 06HGtoE154591736 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Jul 2020 16:55:50 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 15C21A405C; Fri, 17 Jul 2020 16:55:50 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8E7C0A405B; Fri, 17 Jul 2020 16:55:49 +0000 (GMT) Received: from localhost.localdomain (unknown [9.145.6.1]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 17 Jul 2020 16:55:49 +0000 (GMT) From: Ilya Leoshkevich To: Alexei Starovoitov , Daniel Borkmann Cc: bpf@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich Subject: [PATCH 3/5] s390/bpf: use brcl for jumping to exit_ip if necessary Date: Fri, 17 Jul 2020 18:53:24 +0200 Message-Id: <20200717165326.6786-4-iii@linux.ibm.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20200717165326.6786-1-iii@linux.ibm.com> References: <20200717165326.6786-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-17_08:2020-07-17,2020-07-17 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 adultscore=0 spamscore=0 priorityscore=1501 mlxscore=0 mlxlogscore=865 phishscore=0 lowpriorityscore=0 clxscore=1015 malwarescore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007170117 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org "BPF_MAXINSNS: Maximum possible literals" test causes panic with bpf_jit_harden = 2. The reason is that BPF_JMP | BPF_EXIT is always emitted as brc, however, after removal of JITed image size limitations, brcl might be required. Fix by using brcl when necessary. Fixes: 4e9b4a6883dd ("s390/bpf: Use relative long branches") Signed-off-by: Ilya Leoshkevich --- arch/s390/net/bpf_jit_comp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 67608f6092f8..625ebe32b2d1 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1358,8 +1358,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, last = (i == fp->len - 1) ? 1 : 0; if (last) break; - /* j */ - EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg); + if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip)) + /* brc 0xf, */ + EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip); + else + /* brcl 0xf, */ + EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip); break; /* * Branch relative (number of skipped instructions) to offset on