From nobody Sun Feb 8 05:47:59 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.zoho.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 (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1487247327846782.0407256089865; Thu, 16 Feb 2017 04:15:27 -0800 (PST) Received: from localhost ([::1]:46027 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ceKy5-0003TJ-3T for importer@patchew.org; Thu, 16 Feb 2017 07:15:25 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43251) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ceKv2-0000XD-B6 for qemu-devel@nongnu.org; Thu, 16 Feb 2017 07:12:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ceKuz-0002iE-3T for qemu-devel@nongnu.org; Thu, 16 Feb 2017 07:12:16 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:38509) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ceKuy-0002fN-Pq for qemu-devel@nongnu.org; Thu, 16 Feb 2017 07:12:13 -0500 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v1GC3ZeS009698 for ; Thu, 16 Feb 2017 07:12:11 -0500 Received: from e06smtp06.uk.ibm.com (e06smtp06.uk.ibm.com [195.75.94.102]) by mx0a-001b2d01.pphosted.com with ESMTP id 28n8jtgn2s-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 16 Feb 2017 07:12:11 -0500 Received: from localhost by e06smtp06.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 16 Feb 2017 12:12:06 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp02.portsmouth.uk.ibm.com (Postfix) with ESMTP id 7A7452190056; Thu, 16 Feb 2017 12:11:08 +0000 (GMT) Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v1GCC5PT20382048; Thu, 16 Feb 2017 12:12:05 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 34D2C52047; Thu, 16 Feb 2017 11:10:46 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id EA8675203F; Thu, 16 Feb 2017 11:10:45 +0000 (GMT) From: Halil Pasic To: qemu-devel@nongnu.org, "Dr. David Alan Gilbert" Date: Thu, 16 Feb 2017 13:11:37 +0100 X-Mailer: git-send-email 2.8.4 In-Reply-To: <20170216121140.9061-1-pasic@linux.vnet.ibm.com> References: <20170216121140.9061-1-pasic@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 X-Content-Scanned: Fidelis XPS MAILER x-cbid: 17021612-0024-0000-0000-000002B74813 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17021612-0025-0000-0000-0000226D86E8 Message-Id: <20170216121140.9061-3-pasic@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-02-16_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702160121 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 2/5] migration/vmstate: split up vmstate_base_addr 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: Amit Shah , Halil Pasic , Juan Quintela 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" Currently vmstate_base_addr does several things: it pinpoints the field within the struct, possibly allocates memory and possibly does the first pointer dereference. Obviously allocation is needed only for load. Let us split up the functionality in vmstate_base_addr and move the address manipulations (that is everything but the allocation logic) to load and save so it becomes more obvious what is actually going on. Like this all the address calculations (and the handling of the flags controlling these) is in one place and the sequence is more obvious. The newly introduced function vmstate_handle_alloc also fixes the allocation for the unused VMS_VBUFFER| VMS_MULTIPLY scenario and is substantially simpler than the original vmstate_base_addr. In load and save some asserts are added so it's easier to debug situations where we would end up with a null pointer dereference. Signed-off-by: Halil Pasic Reviewed-by: Dr. David Alan Gilbert --- migration/vmstate.c | 39 +++++++++++++++++---------------------- 1 file changed, 17 insertions(+), 22 deletions(-) diff --git a/migration/vmstate.c b/migration/vmstate.c index 36efa80..836a7a4 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -52,29 +52,15 @@ static int vmstate_size(void *opaque, VMStateField *fie= ld) return size; } =20 -static void *vmstate_base_addr(void *opaque, VMStateField *field, bool all= oc) +static void vmstate_handle_alloc(void *ptr, VMStateField *field, void *opa= que) { - void *base_addr =3D opaque + field->offset; - - if (field->flags & VMS_POINTER) { - if (alloc && (field->flags & VMS_ALLOC)) { - gsize size =3D 0; - if (field->flags & VMS_VBUFFER) { - size =3D vmstate_size(opaque, field); - } else { - int n_elems =3D vmstate_n_elems(opaque, field); - if (n_elems) { - size =3D n_elems * field->size; - } - } - if (size) { - *(void **)base_addr =3D g_malloc(size); - } + if (field->flags & VMS_POINTER && field->flags & VMS_ALLOC) { + gsize size =3D vmstate_size(opaque, field); + size *=3D vmstate_n_elems(opaque, field); + if (size) { + *(void **)ptr =3D g_malloc(size); } - base_addr =3D *(void **)base_addr; } - - return base_addr; } =20 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, @@ -116,10 +102,15 @@ int vmstate_load_state(QEMUFile *f, const VMStateDesc= ription *vmsd, field->field_exists(opaque, version_id)) || (!field->field_exists && field->version_id <=3D version_id)) { - void *first_elem =3D vmstate_base_addr(opaque, field, true); + void *first_elem =3D opaque + field->offset; int i, n_elems =3D vmstate_n_elems(opaque, field); int size =3D vmstate_size(opaque, field); =20 + vmstate_handle_alloc(first_elem, field, opaque); + if (field->flags & VMS_POINTER) { + first_elem =3D *(void **)first_elem; + assert(first_elem || !n_elems); + } for (i =3D 0; i < n_elems; i++) { void *curr_elem =3D first_elem + size * i; =20 @@ -321,13 +312,17 @@ void vmstate_save_state(QEMUFile *f, const VMStateDes= cription *vmsd, while (field->name) { if (!field->field_exists || field->field_exists(opaque, vmsd->version_id)) { - void *first_elem =3D vmstate_base_addr(opaque, field, false); + void *first_elem =3D opaque + field->offset; int i, n_elems =3D vmstate_n_elems(opaque, field); int size =3D vmstate_size(opaque, field); int64_t old_offset, written_bytes; QJSON *vmdesc_loop =3D vmdesc; =20 trace_vmstate_save_state_loop(vmsd->name, field->name, n_elems= ); + if (field->flags & VMS_POINTER) { + first_elem =3D *(void **)first_elem; + assert(first_elem || !n_elems); + } for (i =3D 0; i < n_elems; i++) { void *curr_elem =3D first_elem + size * i; =20 --=20 2.8.4