From nobody Tue Feb 10 13:16:21 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 151083416024233.80869155733899; Thu, 16 Nov 2017 04:09:20 -0800 (PST) Received: from localhost ([::1]:40326 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFIyj-0001Om-FR for importer@patchew.org; Thu, 16 Nov 2017 07:09:09 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33991) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eFIpm-0001xe-Ow for qemu-devel@nongnu.org; Thu, 16 Nov 2017 06:59:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eFIpl-0000Pc-KA for qemu-devel@nongnu.org; Thu, 16 Nov 2017 06:59:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48346) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eFIpl-0000P1-Dy for qemu-devel@nongnu.org; Thu, 16 Nov 2017 06:59:53 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 36C11FC7AE; Thu, 16 Nov 2017 11:59:52 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-65.ams2.redhat.com [10.36.117.65]) by smtp.corp.redhat.com (Postfix) with ESMTP id B30B060F87; Thu, 16 Nov 2017 11:59:50 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Thu, 16 Nov 2017 12:59:25 +0100 Message-Id: <20171116115926.16627-11-pbonzini@redhat.com> In-Reply-To: <20171116115926.16627-1-pbonzini@redhat.com> References: <20171116115926.16627-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 16 Nov 2017 11:59:52 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 10/11] exec: Do not resolve subpage in mru_section X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" This fixes a crash caused by picking the wrong memory region in address_space_lookup_region seen with client code accessing a device model that uses alias memory regions. The expensive part of address_space_lookup_region anyway is phys_page_find; performance-wise it is okay to repeat the subsequent subpage lookup. Signed-off-by: BALATON Zoltan Message-Id: <20171114225941.072707456B5@zero.eik.bme.hu> Signed-off-by: Paolo Bonzini --- exec.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/exec.c b/exec.c index 97a24a875e..3bb9fcf257 100644 --- a/exec.c +++ b/exec.c @@ -410,22 +410,16 @@ static MemoryRegionSection *address_space_lookup_regi= on(AddressSpaceDispatch *d, { MemoryRegionSection *section =3D atomic_read(&d->mru_section); subpage_t *subpage; - bool update; =20 - if (section && section !=3D &d->map.sections[PHYS_SECTION_UNASSIGNED] = && - section_covers_addr(section, addr)) { - update =3D false; - } else { + if (!section || section =3D=3D &d->map.sections[PHYS_SECTION_UNASSIGNE= D] || + !section_covers_addr(section, addr)) { section =3D phys_page_find(d, addr); - update =3D true; + atomic_set(&d->mru_section, section); } if (resolve_subpage && section->mr->subpage) { subpage =3D container_of(section->mr, subpage_t, iomem); section =3D &d->map.sections[subpage->sub_section[SUBPAGE_IDX(addr= )]]; } - if (update) { - atomic_set(&d->mru_section, section); - } return section; } =20 --=20 2.14.3