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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 ED627C433E0 for ; Fri, 8 Jan 2021 13:27:31 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8890C235FF for ; Fri, 8 Jan 2021 13:27:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8890C235FF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34454 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kxrne-0001bK-8i for qemu-devel@archiver.kernel.org; Fri, 08 Jan 2021 08:27:30 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40038) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kxrhW-0005n5-Oa for qemu-devel@nongnu.org; Fri, 08 Jan 2021 08:21:10 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:52024) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kxrhU-0002mZ-Mk for qemu-devel@nongnu.org; Fri, 08 Jan 2021 08:21:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610112068; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=7HcHqSvmrMM7rKL0EaaDfO3SAVmfU+tWX+JLtEAfu9U=; b=S1TeJSHqe6smoftap8kv5VxSkkWju+EtqFoL6/ejcp2p+43e6vk12a2tmclisxX5U8vczq iZvR6J2aQMIQ8ZX5miUhbfKu6m6uuEb2hpblDn/GHwrF6SPs1MaWb5/3ZbtQu/ZIctuGU1 V5LpSdS/nCGDzn0GfTwldKO/dBbvjKY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-188-Zm892t7NMuWUbQtk-hxpzg-1; Fri, 08 Jan 2021 08:21:04 -0500 X-MC-Unique: Zm892t7NMuWUbQtk-hxpzg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F2B61801817; Fri, 8 Jan 2021 13:21:02 +0000 (UTC) Received: from t480s.redhat.com (ovpn-114-168.ams2.redhat.com [10.36.114.168]) by smtp.corp.redhat.com (Postfix) with ESMTP id F3DAB5D9C0; Fri, 8 Jan 2021 13:21:00 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Subject: [PATCH v2 3/4] s390x/tcg: Only ignore content in r0 when specified via "b" or "x" Date: Fri, 8 Jan 2021 14:20:48 +0100 Message-Id: <20210108132049.8501-4-david@redhat.com> In-Reply-To: <20210108132049.8501-1-david@redhat.com> References: <20210108132049.8501-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=david@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Received-SPF: pass client-ip=63.128.21.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.247, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Thomas Huth , David Hildenbrand , Richard Henderson , Heiko Carstens , Cornelia Huck , Nick Desaulniers , Christian Borntraeger , qemu-s390x@nongnu.org, Guenter Roeck Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Using get_address() with register identifiers comming from an "r" field is wrong: if the "r" field designates "r0", we don't read the content and instead assume 0 - which should only be applied when the register was specified via "b" or "x". PoP 5-11 "Operand-Address Generation": "A zero in any of the B1, B2, X2, B3, or B4 fields indicates the absence of the corresponding address component. For the absent component, a zero is used in forming the intermediate sum, regardless of the contents of general register 0. A displacement of zero has no special significance." This BUG became visible for CSPG as generated by LLVM-12 in the upstream Linux kernel (v5.11-rc2), used while creating the linear mapping in vmem_map_init(): Trying to store to address 0 results in a Low Address Protection exception. Debugging this was more complicated than it could have been: The program interrupt handler in the kernel will try to crash the kernel: doing so, it will enable DAT. As the linear mapping is not created yet (asce=0), we run into an addressing exception while tring to walk non-existant DAT tables, resulting in a program exception loop. This allows for booting upstream Linux kernels compiled by clang-12. Most of these cases seem to be broken forever. Reported-by: Nick Desaulniers Cc: Guenter Roeck Cc: Christian Borntraeger Cc: Heiko Carstens Signed-off-by: David Hildenbrand --- target/s390x/insn-data.def | 8 ++++---- target/s390x/translate.c | 15 +++++++++------ 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def index eac5136ee5..e5b6efabf3 100644 --- a/target/s390x/insn-data.def +++ b/target/s390x/insn-data.def @@ -1290,8 +1290,8 @@ F(0xe313, LRAY, RXY_a, LD, 0, a2, r1, 0, lra, 0, IF_PRIV) F(0xe303, LRAG, RXY_a, Z, 0, a2, r1, 0, lra, 0, IF_PRIV) /* LOAD USING REAL ADDRESS */ - E(0xb24b, LURA, RRE, Z, 0, 0, new, r1_32, lura, 0, MO_TEUL, IF_PRIV) - E(0xb905, LURAG, RRE, Z, 0, 0, r1, 0, lura, 0, MO_TEQ, IF_PRIV) + E(0xb24b, LURA, RRE, Z, 0, ra2, new, r1_32, lura, 0, MO_TEUL, IF_PRIV) + E(0xb905, LURAG, RRE, Z, 0, ra2, r1, 0, lura, 0, MO_TEQ, IF_PRIV) /* MOVE TO PRIMARY */ F(0xda00, MVCP, SS_d, Z, la1, a2, 0, 0, mvcp, 0, IF_PRIV) /* MOVE TO SECONDARY */ @@ -1344,8 +1344,8 @@ /* STORE THEN OR SYSTEM MASK */ F(0xad00, STOSM, SI, Z, la1, 0, 0, 0, stnosm, 0, IF_PRIV) /* STORE USING REAL ADDRESS */ - E(0xb246, STURA, RRE, Z, r1_o, 0, 0, 0, stura, 0, MO_TEUL, IF_PRIV) - E(0xb925, STURG, RRE, Z, r1_o, 0, 0, 0, stura, 0, MO_TEQ, IF_PRIV) + E(0xb246, STURA, RRE, Z, r1_o, ra2, 0, 0, stura, 0, MO_TEUL, IF_PRIV) + E(0xb925, STURG, RRE, Z, r1_o, ra2, 0, 0, stura, 0, MO_TEQ, IF_PRIV) /* TEST BLOCK */ F(0xb22c, TB, RRE, Z, 0, r2_o, 0, 0, testblock, 0, IF_PRIV) /* TEST PROTECTION */ diff --git a/target/s390x/translate.c b/target/s390x/translate.c index 39e33eeb67..61dd0341e4 100644 --- a/target/s390x/translate.c +++ b/target/s390x/translate.c @@ -3285,8 +3285,7 @@ static DisasJumpType op_lpq(DisasContext *s, DisasOps *o) #ifndef CONFIG_USER_ONLY static DisasJumpType op_lura(DisasContext *s, DisasOps *o) { - o->addr1 = get_address(s, 0, get_field(s, r2), 0); - tcg_gen_qemu_ld_tl(o->out, o->addr1, MMU_REAL_IDX, s->insn->data); + tcg_gen_qemu_ld_tl(o->out, o->in2, MMU_REAL_IDX, s->insn->data); return DISAS_NEXT; } #endif @@ -4234,7 +4233,8 @@ static DisasJumpType op_ectg(DisasContext *s, DisasOps *o) tcg_gen_addi_i64(o->in1, regs[b1], d1); o->in2 = tcg_temp_new_i64(); tcg_gen_addi_i64(o->in2, regs[b2], d2); - o->addr1 = get_address(s, 0, r3, 0); + o->addr1 = tcg_temp_new_i64(); + gen_addi_and_wrap_i64(s, o->addr1, regs[r3], 0); /* load the third operand into r3 before modifying anything */ tcg_gen_qemu_ld64(regs[r3], o->addr1, get_mem_index(s)); @@ -4539,8 +4539,7 @@ static DisasJumpType op_stnosm(DisasContext *s, DisasOps *o) static DisasJumpType op_stura(DisasContext *s, DisasOps *o) { - o->addr1 = get_address(s, 0, get_field(s, r2), 0); - tcg_gen_qemu_st_tl(o->in1, o->addr1, MMU_REAL_IDX, s->insn->data); + tcg_gen_qemu_st_tl(o->in1, o->in2, MMU_REAL_IDX, s->insn->data); if (s->base.tb->flags & FLAG_MASK_PER) { update_psw_addr(s); @@ -5923,7 +5922,11 @@ static void in2_x2l(DisasContext *s, DisasOps *o) static void in2_ra2(DisasContext *s, DisasOps *o) { - o->in2 = get_address(s, 0, get_field(s, r2), 0); + int r2 = get_field(s, r2); + + /* Note: *don't* treat !r2 as 0, use the reg value. */ + o->in2 = tcg_temp_new_i64(); + gen_addi_and_wrap_i64(s, o->in2, regs[r2], 0); } #define SPEC_in2_ra2 0 -- 2.29.2