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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 EB687C433DB for ; Wed, 24 Mar 2021 09:20:19 +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 22275619E5 for ; Wed, 24 Mar 2021 09:20:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22275619E5 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]:50006 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lOzgX-0000fO-VR for qemu-devel@archiver.kernel.org; Wed, 24 Mar 2021 05:20:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46602) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOzdt-0006Z7-OV for qemu-devel@nongnu.org; Wed, 24 Mar 2021 05:17:34 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:44855) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOzdm-0008QP-2e for qemu-devel@nongnu.org; Wed, 24 Mar 2021 05:17:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616577443; 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=7/GXiX5ZJ1cX+7W2jhJZxSBTuwWgeMUIEGujJoTgcck=; b=MbP0mYzpkq0b0ktq81SY5rUqOaWuKEO1K86kNdTpEV/d7Tm8cB3RERd5OvlwHpTNc/ECln n0Ri3CHB+SHwu2akGqYhyMkXl7dJj6WPBcnNbBLPWcS9ib6gAVrdjIfDTgeuUIWz4kzCeQ mUBL8XUPfSMUkOIix3Swk0ndlN3M20g= 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-349-IzPWaOXgNSKKdsCJy8BBZw-1; Wed, 24 Mar 2021 05:17:21 -0400 X-MC-Unique: IzPWaOXgNSKKdsCJy8BBZw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A901C8143FE; Wed, 24 Mar 2021 09:17:20 +0000 (UTC) Received: from [10.36.115.66] (ovpn-115-66.ams2.redhat.com [10.36.115.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC8996A046; Wed, 24 Mar 2021 09:17:19 +0000 (UTC) Subject: Re: [PATCH 1/1] linux-user/s390x: Apply h2g to address of sigreturn stub To: Andreas Krebbel , qemu-devel@nongnu.org References: <20210324085129.29684-1-krebbel@linux.ibm.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <5070a253-cd95-59b0-dbdb-2eb549e9f61c@redhat.com> Date: Wed, 24 Mar 2021 10:17:18 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210324085129.29684-1-krebbel@linux.ibm.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 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-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, 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=unavailable 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: qemu-s390x@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 24.03.21 09:51, Andreas Krebbel wrote: > The sigreturn SVC is put onto the stack by the emulation code. Hence > the address of it should not be subject to guest_base transformation > when fetching it. > > The fix applies h2g to the address when writing it into the return > address register to nullify the transformation applied to it later. > > Note: This only caused problems if Qemu has been built with > --disable-pie (as it is in distros nowadays). Otherwise guest_base > defaults to 0 hiding the actual problem. > > Signed-off-by: Andreas Krebbel > --- > linux-user/s390x/signal.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/linux-user/s390x/signal.c b/linux-user/s390x/signal.c > index ecfa2a14a9..1412376958 100644 > --- a/linux-user/s390x/signal.c > +++ b/linux-user/s390x/signal.c > @@ -152,7 +152,7 @@ void setup_frame(int sig, struct target_sigaction *ka, > env->regs[14] = (unsigned long) > ka->sa_restorer | PSW_ADDR_AMODE; > } else { > - env->regs[14] = (frame_addr + offsetof(sigframe, retcode)) > + env->regs[14] = h2g(frame_addr + offsetof(sigframe, retcode)) > | PSW_ADDR_AMODE; > __put_user(S390_SYSCALL_OPCODE | TARGET_NR_sigreturn, > (uint16_t *)(frame->retcode)); > @@ -213,7 +213,7 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, > if (ka->sa_flags & TARGET_SA_RESTORER) { > env->regs[14] = (unsigned long) ka->sa_restorer | PSW_ADDR_AMODE; > } else { > - env->regs[14] = (unsigned long) frame->retcode | PSW_ADDR_AMODE; > + env->regs[14] = (unsigned long) h2g(frame->retcode) | PSW_ADDR_AMODE; > __put_user(S390_SYSCALL_OPCODE | TARGET_NR_rt_sigreturn, > (uint16_t *)(frame->retcode)); > } > Sounds sane to me, although I am not an expert on that code :) Acked-by: David Hildenbrand -- Thanks, David / dhildenb