From nobody Thu Nov 6 14:14:57 2025 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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1542114217733772.8758912971867; Tue, 13 Nov 2018 05:03:37 -0800 (PST) Received: from localhost ([::1]:53756 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gMYLn-0003mv-44 for importer@patchew.org; Tue, 13 Nov 2018 08:03:27 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51865) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gMYKn-0003Sf-U5 for qemu-devel@nongnu.org; Tue, 13 Nov 2018 08:02:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gMYKh-00079J-Oy for qemu-devel@nongnu.org; Tue, 13 Nov 2018 08:02:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45482) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gMYKh-00075s-FN for qemu-devel@nongnu.org; Tue, 13 Nov 2018 08:02:19 -0500 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 mx1.redhat.com (Postfix) with ESMTPS id 543EB80F8D; Tue, 13 Nov 2018 13:02:18 +0000 (UTC) Received: from t460s.redhat.com (ovpn-116-155.ams2.redhat.com [10.36.116.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id C93B560BE4; Tue, 13 Nov 2018 13:01:31 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Date: Tue, 13 Nov 2018 14:01:29 +0100 Message-Id: <20181113130129.26558-1-david@redhat.com> In-Reply-To: <20181023152306.3123-8-david@redhat.com> References: <20181023152306.3123-8-david@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Tue, 13 Nov 2018 13:02:18 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v4] memory-device: rewrite address assignment using ranges 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: , Cc: Eduardo Habkost , "Michael S . Tsirkin" , David Hildenbrand , Michael Roth , Markus Armbruster , Igor Mammedov , "Dr . David Alan Gilbert" , David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Let's rewrite it properly using ranges. This fixes certain overflows that are right now possible. E.g. qemu-system-x86_64 -m 4G,slots=3D20,maxmem=3D40G -M pc \ -object memory-backend-file,id=3Dmem1,share,mem-path=3D/dev/zero,size= =3D2G -device pc-dimm,memdev=3Dmem1,id=3Ddimm1,addr=3D-0x40000000 Now properly errors out instead of succeeding. (Note that qapi parsing of huge uint64_t values is broken and fixes are on the way) "can't add memory device [0xffffffffa0000000:0x80000000], usable range for memory devices [0x140000000:0xe00000000]" Signed-off-by: David Hildenbrand --- v3 -> v4: - Use better error messages - Fix one theretical overflow hw/mem/memory-device.c | 54 ++++++++++++++++++++++++------------------ 1 file changed, 31 insertions(+), 23 deletions(-) diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c index 8be63c8032..28e871f562 100644 --- a/hw/mem/memory-device.c +++ b/hw/mem/memory-device.c @@ -100,9 +100,8 @@ static uint64_t memory_device_get_free_addr(MachineStat= e *ms, uint64_t align, uint64_t size, Error **errp) { - uint64_t address_space_start, address_space_end; GSList *list =3D NULL, *item; - uint64_t new_addr =3D 0; + Range as, new =3D range_empty; =20 if (!ms->device_memory) { error_setg(errp, "memory devices (e.g. for memory hotplug) are not= " @@ -115,13 +114,11 @@ static uint64_t memory_device_get_free_addr(MachineSt= ate *ms, "enabled, please specify the maxmem option"); return 0; } - address_space_start =3D ms->device_memory->base; - address_space_end =3D address_space_start + - memory_region_size(&ms->device_memory->mr); - g_assert(address_space_end >=3D address_space_start); + range_init_nofail(&as, ms->device_memory->base, + memory_region_size(&ms->device_memory->mr)); =20 - /* address_space_start indicates the maximum alignment we expect */ - if (!QEMU_IS_ALIGNED(address_space_start, align)) { + /* start of address space indicates the maximum alignment we expect */ + if (!QEMU_IS_ALIGNED(range_lob(&as), align)) { error_setg(errp, "the alignment (0x%" PRIx64 ") is not supported", align); return 0; @@ -145,20 +142,25 @@ static uint64_t memory_device_get_free_addr(MachineSt= ate *ms, } =20 if (hint) { - new_addr =3D *hint; - if (new_addr < address_space_start) { + if (range_init(&new, *hint, size)) { error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" = PRIx64 - "] before 0x%" PRIx64, new_addr, size, - address_space_start); + "], usable range for memory devices [0x%" PRIx64 ":= 0x%" + PRIx64 "]", *hint, size, range_lob(&as), + range_size(&as)); return 0; - } else if ((new_addr + size) > address_space_end) { + } + if (!range_contains_range(&as, &new)) { error_setg(errp, "can't add memory device [0x%" PRIx64 ":0x%" = PRIx64 - "] beyond 0x%" PRIx64, new_addr, size, - address_space_end); + "], usable range for memory devices [0x%" PRIx64 ":= 0x%" + PRIx64 "]", range_lob(&new), range_size(&new), + range_lob(&as), range_size(&as)); return 0; } } else { - new_addr =3D address_space_start; + if (range_init(&new, range_lob(&as), size)) { + error_setg(errp, "can't add memory device, device too big"); + return 0; + } } =20 /* find address range that will fit new memory device */ @@ -166,30 +168,36 @@ static uint64_t memory_device_get_free_addr(MachineSt= ate *ms, for (item =3D list; item; item =3D g_slist_next(item)) { const MemoryDeviceState *md =3D item->data; const MemoryDeviceClass *mdc =3D MEMORY_DEVICE_GET_CLASS(OBJECT(md= )); - uint64_t md_size, md_addr; + uint64_t next_addr; + Range tmp; =20 - md_addr =3D mdc->get_addr(md); - md_size =3D memory_device_get_region_size(md, &error_abort); + range_init_nofail(&tmp, mdc->get_addr(md), + memory_device_get_region_size(md, &error_abort)); =20 - if (ranges_overlap(md_addr, md_size, new_addr, size)) { + if (range_overlaps_range(&tmp, &new)) { if (hint) { const DeviceState *d =3D DEVICE(md); error_setg(errp, "address range conflicts with memory devi= ce" " id=3D'%s'", d->id ? d->id : "(unnamed)"); goto out; } - new_addr =3D QEMU_ALIGN_UP(md_addr + md_size, align); + + next_addr =3D QEMU_ALIGN_UP(range_upb(&tmp) + 1, align); + if (!next_addr || range_init(&new, next_addr, range_size(&new)= )) { + range_make_empty(&new); + break; + } } } =20 - if (new_addr + size > address_space_end) { + if (!range_contains_range(&as, &new)) { error_setg(errp, "could not find position in guest address space f= or " "memory device - memory fragmented due to alignments"); goto out; } out: g_slist_free(list); - return new_addr; + return range_lob(&new); } =20 MemoryDeviceInfoList *qmp_memory_device_list(void) --=20 2.17.2