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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 6DAC6C3A5AA for ; Wed, 4 Sep 2019 16:12:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 440C72053B for ; Wed, 4 Sep 2019 16:12:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567613521; bh=MvYti3+n7kM/43yLnLVWf0pMoCa1vY6xzGEgd7FD1J4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sjkBKH4hJU+Gu4DpvKEmweqNNW2KKcBl0dBIk13r0CNwqpnxKjiZnlllVp1ZXC88w gBX24Iez3KEtD+9XAgRImPzCIjvswE6ZOsZZpaSm6BnktHCuC+c6whVeO43wGN0vvg cvjVQ2uboiFWNsW6rqMntAnP4nLH25/FWOl2C1BI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732653AbfIDQAW (ORCPT ); Wed, 4 Sep 2019 12:00:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:35218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732649AbfIDQAV (ORCPT ); Wed, 4 Sep 2019 12:00:21 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E6A4A22DBF; Wed, 4 Sep 2019 16:00:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567612820; bh=MvYti3+n7kM/43yLnLVWf0pMoCa1vY6xzGEgd7FD1J4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Rt+hQyaIh7CdP036AjtFLXhveCBrsExntT9/qrTjjAB7iNMAVPQbsgcC3i2s2pdLF C+Gb/TDBq8yLRBC23UKFyFt4Jn66vcSUuMcQXh7Hutim2BOiLypIwHjwn0HwFYWK3X HehbV2P9Injerao6Nsz2FAqWCtxeoZzX8xv+QPos= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ilya Leoshkevich , Yauheni Kaliuta , Vasily Gorbik , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 11/52] s390/bpf: use 32-bit index for tail calls Date: Wed, 4 Sep 2019 11:59:23 -0400 Message-Id: <20190904160004.3671-11-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190904160004.3671-1-sashal@kernel.org> References: <20190904160004.3671-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 a3ce1fdc3d802..2617e426c7926 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1015,8 +1015,8 @@ 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); /* @@ -1042,8 +1042,10 @@ 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