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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 1B5FDC433E1 for ; Mon, 17 Aug 2020 15:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE184208E4 for ; Mon, 17 Aug 2020 15:37:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597678641; bh=puuZK4Hc/ru+F/LefG+5ZC9v99mVnZgP2MsXOFegl9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=e597Cj+4y0pWLN8zBxaUyX3ZdzxjF7fSwG88C3UMmWaXLtlX/F0kAgQh/Kxw5hFMw 1+/UNYZAGBD01PFCMNOwNw8ZUGy7DkBcWcTCw5e70elOTR1Xc/fojs6eI+QBfmTitx DrfTW5vxNuEAUvaccvSbp23aJ7y0TMXrmZqhNjzU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387405AbgHQPhQ (ORCPT ); Mon, 17 Aug 2020 11:37:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:54458 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730262AbgHQPbJ (ORCPT ); Mon, 17 Aug 2020 11:31:09 -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 464352245C; Mon, 17 Aug 2020 15:31:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597678268; bh=puuZK4Hc/ru+F/LefG+5ZC9v99mVnZgP2MsXOFegl9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UDuHtfXDDkoW0gR51mirMoKE5vsHd2mKqeAtdJjTOhdBGCw7uOLWaEMmnj2hUlwCt Rp3OcEL/ZUUUaJjrJ+PdbQajnOvivTktYKJlGvQvZAPCM8rBzYq7e/eV7YlXZlfMnU joz+mtmj9IMYalzrScdBbUxdIfgG6flGZV/W/vRM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ilya Leoshkevich , Alexei Starovoitov , Sasha Levin Subject: [PATCH 5.8 275/464] s390/bpf: Use brcl for jumping to exit_ip if necessary Date: Mon, 17 Aug 2020 17:13:48 +0200 Message-Id: <20200817143846.943990302@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143833.737102804@linuxfoundation.org> References: <20200817143833.737102804@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 5fa6974471c5518a50bdd814067508dbcb477251 ] "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 Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200717165326.6786-4-iii@linux.ibm.com Signed-off-by: Sasha Levin --- 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 6b3d612948fba..6b8968f6e207d 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1268,8 +1268,12 @@ 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 -- 2.25.1