From nobody Wed Nov 27 06:45:40 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1700069271318504.7512871162594; Wed, 15 Nov 2023 09:27:51 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r3Jfx-0006D2-Tu; Wed, 15 Nov 2023 12:27:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3Jfu-00064m-UQ; Wed, 15 Nov 2023 12:27:39 -0500 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3Jfr-0007kn-B9; Wed, 15 Nov 2023 12:27:38 -0500 Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1r3Jfi-004Bc1-25; Wed, 15 Nov 2023 17:27:26 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96.2 #2 (Red Hat Linux)) id 1r3Jfh-004sFD-0h; Wed, 15 Nov 2023 17:27:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=nb4/k2mDzWcTB0WCWH1Sc4XyVKQa4fT5IUZadSOtr3A=; b=lHv8bWujGEmJl9ObnRZwBoZQPl gX7tpE1PWf5bAAP/UlMIQIio4a2+QZqHthuG5aA3qkM2vZGDvL5XqQUXCoSnzqjPG6NHqUcj4pj5b Mj1nNHARxT6exhbrY5ga6H1FrO8o05cTq5+WWJBFm91uuwEnQ8EzHGWimoZinGk1cdhlBAqqsZ5QL GPDIhHeAok8hk8s6DJUXW2FudVHzasFQHMao+kuK0m5SZB2wF4CID3aUheWtD2zRHP/ntD05fSCB4 2a9vXKFFmi34fk5gkSWR/cPvRHT6ChZ5j7eOKvGC2SWcvDE6xX9s9ZZtt2nGZUNY0T+3jH3tZZzZM gAVhOqKA==; From: David Woodhouse To: qemu-devel@nongnu.org Cc: Stefano Stabellini , Anthony Perard , Paul Durrant , Kevin Wolf , Hanna Reitz , Jason Wang , Paolo Bonzini , xen-devel@lists.xenproject.org, qemu-block@nongnu.org Subject: [PATCH 1/3] net: do not delete nics in net_cleanup() Date: Wed, 15 Nov 2023 17:24:35 +0000 Message-ID: <20231115172723.1161679-2-dwmw2@infradead.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231115172723.1161679-1-dwmw2@infradead.org> References: <20231115172723.1161679-1-dwmw2@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=2001:8b0:10b:1:d65d:64ff:fe57:4e05; envelope-from=BATV+a72437c23eaab18a7e37+7388+infradead.org+dwmw2@desiato.srs.infradead.org; helo=desiato.infradead.org X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 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-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1700069272642100007 Content-Type: text/plain; charset="utf-8" From: David Woodhouse In net_cleanup() we only need to delete the netdevs, as those may have state which outlives Qemu when it exits, and thus may actually need to be cleaned up on exit. The nics, on the other hand, are owned by the device which created them. Most devices don't bother to clean up on exit because they don't have any state which will outlive Qemu... but XenBus devices do need to clean up their nodes in XenStore, and do have an exit handler to delete them. When the XenBus exit handler destroys the xen-net-device, it attempts to delete its nic after net_cleanup() had already done so. And crashes. Fix this by only deleting netdevs as we walk the list. As the comment notes, we can't use QTAILQ_FOREACH_SAFE() as each deletion may remove *multiple* entries, including the "safely" saved 'next' pointer. But we can store the *previous* entry, since nics are safe. Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- net/net.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/net/net.c b/net/net.c index c0c0cbe99e..bbe33da176 100644 --- a/net/net.c +++ b/net/net.c @@ -1499,18 +1499,34 @@ static void net_vm_change_state_handler(void *opaqu= e, bool running, =20 void net_cleanup(void) { - NetClientState *nc; + NetClientState *nc, **p =3D &QTAILQ_FIRST(&net_clients); =20 /*cleanup colo compare module for COLO*/ colo_compare_cleanup(); =20 - /* We may del multiple entries during qemu_del_net_client(), - * so QTAILQ_FOREACH_SAFE() is also not safe here. + /* + * Walk the net_clients list and remove the netdevs but *not* any + * NET_CLIENT_DRIVER_NIC entries. The latter are owned by the device + * model which created them, and in some cases (e.g. xen-net-device) + * the device itself may do cleanup at exit and will be upset if we + * just delete its NIC from underneath it. + * + * Since qemu_del_net_client() may delete multiple entries, using + * QTAILQ_FOREACH_SAFE() is not safe here. The only safe pointer + * to keep as a bookmark is a NET_CLIENT_DRIVER_NIC entry, so keep + * 'p' pointing to either the head of the list, or the 'next' field + * of the latest NET_CLIENT_DRIVER_NIC, and operate on *p as we walk + * the list. + * + * The 'nc' variable isn't part of the list traversal; it's purely + * for convenience as too much '(*p)->' has a tendency to make the + * readers' eyes bleed. */ - while (!QTAILQ_EMPTY(&net_clients)) { - nc =3D QTAILQ_FIRST(&net_clients); + while (*p) { + nc =3D *p; if (nc->info->type =3D=3D NET_CLIENT_DRIVER_NIC) { - qemu_del_nic(qemu_get_nic(nc)); + /* Skip NET_CLIENT_DRIVER_NIC entries */ + p =3D &QTAILQ_NEXT(nc, next); } else { qemu_del_net_client(nc); } --=20 2.41.0 From nobody Wed Nov 27 06:45:40 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1700069283832495.213662090978; Wed, 15 Nov 2023 09:28:03 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r3Jfx-0006DD-V9; Wed, 15 Nov 2023 12:27:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3Jfw-000657-8R; Wed, 15 Nov 2023 12:27:40 -0500 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3Jfr-0007ju-Am; Wed, 15 Nov 2023 12:27:38 -0500 Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1r3Jfh-00FTE8-Nd; Wed, 15 Nov 2023 17:27:25 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96.2 #2 (Red Hat Linux)) id 1r3Jfh-004sFH-0w; Wed, 15 Nov 2023 17:27:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=U2nfIn0v8qQcweyjpuwetdqXtDTacmG9Ew4TFyBXTIk=; b=Z0hyEVwBzW2EjTAYTKEL9c5Jxb FIFLgifQJSEBNQMSx1dJbhnwRd5EyKn413VSvoQitCGS1XgTHSiuwuY1iKWaOjex+I+QwAtNtIkrZ ncu525Eu5aYcICJbRPH0prOFfUd7psULCeDYK1sd+1u8YT/uOWkTt+l2/HBIOf6Ok5JiT6BGVN4K/ dPLPIQMMl72swFVHG5VOl9pTmf/iEojG7bdPQwBgUBDl2Bt90S8SMmypzJxsdYFt+nSJB12Kd96IL 9BOfxKI4YY8f13ViEYj0RRLpzy6cDH/Si+CJs/FBAzOU6eL1n+y8cCdjZXlA7grXwNcE2848vcEG8 KYSN3t1A==; From: David Woodhouse To: qemu-devel@nongnu.org Cc: Stefano Stabellini , Anthony Perard , Paul Durrant , Kevin Wolf , Hanna Reitz , Jason Wang , Paolo Bonzini , xen-devel@lists.xenproject.org, qemu-block@nongnu.org Subject: [PATCH 2/3] vl: disable default serial when xen-console is enabled Date: Wed, 15 Nov 2023 17:24:36 +0000 Message-ID: <20231115172723.1161679-3-dwmw2@infradead.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231115172723.1161679-1-dwmw2@infradead.org> References: <20231115172723.1161679-1-dwmw2@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=2001:8b0:10b:1236::1; envelope-from=BATV+a96bd05b928ee04f18d5+7388+infradead.org+dwmw2@casper.srs.infradead.org; helo=casper.infradead.org X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 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-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1700069285031100001 Content-Type: text/plain; charset="utf-8" From: David Woodhouse If a Xen console is configured on the command line, do not add a default serial port. Signed-off-by: David Woodhouse Reviewed-by: Marc-Andr=C3=A9 Lureau Reviewed-by: Paul Durrant --- system/vl.c | 1 + 1 file changed, 1 insertion(+) diff --git a/system/vl.c b/system/vl.c index 5af7ced2a1..8109231834 100644 --- a/system/vl.c +++ b/system/vl.c @@ -198,6 +198,7 @@ static const struct { const char *driver; int *flag; } default_list[] =3D { + { .driver =3D "xen-console", .flag =3D &default_serial }, { .driver =3D "isa-serial", .flag =3D &default_serial }, { .driver =3D "isa-parallel", .flag =3D &default_parallel }, { .driver =3D "isa-fdc", .flag =3D &default_floppy }, --=20 2.41.0 From nobody Wed Nov 27 06:45:40 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1700069304867780.0130224203954; Wed, 15 Nov 2023 09:28:24 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r3Jfv-00065P-J4; Wed, 15 Nov 2023 12:27:39 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3Jfu-00062e-Mt; Wed, 15 Nov 2023 12:27:38 -0500 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r3Jfr-0007km-9x; Wed, 15 Nov 2023 12:27:38 -0500 Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1r3Jfi-004Bc2-26; Wed, 15 Nov 2023 17:27:26 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.96.2 #2 (Red Hat Linux)) id 1r3Jfh-004sFL-16; Wed, 15 Nov 2023 17:27:25 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=iJEkdS0pn0NaWuyuJa10RygKkR2b5taCeZjDdDEb+V8=; b=kAKl+Xku2nRKfIhSLPH3+fjd8S PIIIAjYbVjC4xBDHZaXNvD0z9x58yFQGqYFlfOnrlK+4kceqKQqBzVf/04nDaW7UNNcPAq7CN3GON 53EQfv1KL4qKFIxx1w0US+jxdYqvXc7rz+VeWnWsY6SMjejou4sfApYbzAtwVZtc+xAb7CnxLZO8h fGQ4l0vEe7cWQ+BAJAboVAzNGMLlBX3Azmy5PcL6SK0RsmpuFWKpXr02LRE5FrafLzTVJHR/q/xlr /DjObAZMr4mskpzSgSE0g6R8w8U3d6Pj9cs6eGpjrhG0hEQEBZfInO3RbFgBLxC6gPbX0LxKhDsjk P2AENoUQ==; From: David Woodhouse To: qemu-devel@nongnu.org Cc: Stefano Stabellini , Anthony Perard , Paul Durrant , Kevin Wolf , Hanna Reitz , Jason Wang , Paolo Bonzini , xen-devel@lists.xenproject.org, qemu-block@nongnu.org Subject: [PATCH 3/3] hw/xen: clean up xen_block_find_free_vdev() to avoid Coverity false positive Date: Wed, 15 Nov 2023 17:24:37 +0000 Message-ID: <20231115172723.1161679-4-dwmw2@infradead.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231115172723.1161679-1-dwmw2@infradead.org> References: <20231115172723.1161679-1-dwmw2@infradead.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SRS-Rewrite: SMTP reverse-path rewritten from by desiato.infradead.org. See http://www.infradead.org/rpr.html Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: none client-ip=2001:8b0:10b:1:d65d:64ff:fe57:4e05; envelope-from=BATV+a72437c23eaab18a7e37+7388+infradead.org+dwmw2@desiato.srs.infradead.org; helo=desiato.infradead.org X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 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-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1700069306588100003 Content-Type: text/plain; charset="utf-8" From: David Woodhouse Coverity couldn't see that nr_existing was always going to be zero when qemu_xen_xs_directory() returned NULL in the ENOENT case (CID 1523906). Perhaps more to the point, neither could Peter at first glance. Improve the code to hopefully make it clearer to Coverity and human reviewers alike. Signed-off-by: David Woodhouse Reviewed-by: Paul Durrant --- hw/block/xen-block.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index 6d64ede94f..aed1d5c330 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -91,9 +91,27 @@ static bool xen_block_find_free_vdev(XenBlockDevice *blo= ckdev, Error **errp) =20 existing_frontends =3D qemu_xen_xs_directory(xenbus->xsh, XBT_NULL, fe= _path, &nr_existing); - if (!existing_frontends && errno !=3D ENOENT) { - error_setg_errno(errp, errno, "cannot read %s", fe_path); - return false; + if (!existing_frontends) { + if (errno =3D=3D ENOENT) { + /* + * If the frontend directory doesn't exist because there are + * no existing vbd devices, that's fine. Just ensure that we + * don't dereference the NULL existing_frontends pointer, by + * checking that nr_existing is zero so the loop below is not + * entered. + * + * In fact this is redundant since nr_existing is initialized + * to zero, but setting it again here makes it abundantly clear + * to Coverity, and to the human reader who doesn't know the + * semantics of qemu_xen_xs_directory() off the top of their + * head. + */ + nr_existing =3D 0; + } else { + /* All other errors accessing the frontend directory are fatal= . */ + error_setg_errno(errp, errno, "cannot read %s", fe_path); + return false; + } } =20 memset(used_devs, 0, sizeof(used_devs)); --=20 2.41.0