From patchwork Tue Mar 15 18:34:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 8591731 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id ADF08C0553 for ; Tue, 15 Mar 2016 18:49:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0F509202EC for ; Tue, 15 Mar 2016 18:49:27 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4D5A2202E6 for ; Tue, 15 Mar 2016 18:49:26 +0000 (UTC) Received: from localhost ([::1]:50733 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afu21-0001m7-Og for patchwork-qemu-devel@patchwork.kernel.org; Tue, 15 Mar 2016 14:49:25 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43740) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afto9-0006fw-Uk for qemu-devel@nongnu.org; Tue, 15 Mar 2016 14:35:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1afto8-0001qp-H3 for qemu-devel@nongnu.org; Tue, 15 Mar 2016 14:35:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48674) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1afto8-0001qS-8S for qemu-devel@nongnu.org; Tue, 15 Mar 2016 14:35:04 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id DC2A146215; Tue, 15 Mar 2016 18:35:03 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-46.ams2.redhat.com [10.36.116.46]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2FIZ1de007805 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 15 Mar 2016 14:35:02 -0400 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 2EF2B30052F2; Tue, 15 Mar 2016 19:34:57 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Tue, 15 Mar 2016 19:34:39 +0100 Message-Id: <1458066895-20632-25-git-send-email-armbru@redhat.com> In-Reply-To: <1458066895-20632-1-git-send-email-armbru@redhat.com> References: <1458066895-20632-1-git-send-email-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: claudio.fontana@huawei.com, cam@cs.ualberta.ca, mlureau@redhat.com, david.marchand@6wind.com, pbonzini@redhat.com Subject: [Qemu-devel] [PATCH v3 24/40] ivshmem: Plug leaks on unplug, fix peer disconnect X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP close_peer_eventfds() cleans up three things: ioeventfd triggers if they exist, eventfds, and the array to store them. Commit 98609cd (v1.2.0) fixed it not to clean up ioeventfd triggers when they don't exist (property ioeventfd=off, which is the default). Unfortunately, the fix also made it skip cleanup of the eventfds and the array then. This is a memory and file descriptor leak on unplug. Additionally, the reset of nb_eventfds is skipped. Doesn't matter on unplug. On peer disconnect, however, this permanently wedges the interrupt vectors used for that peer's ID. The eventfds stay behind, but aren't connected to a peer anymore. When the ID gets recycled for a new peer, the new peer's eventfds get assigned to vectors after the old ones. Commonly, the device's number of vectors matches the server's, so the new ones get dropped with a "Too many eventfd received" message. Interrupts either don't work (common case) or go to the wrong vector. Fix by narrowing the conditional to just the ioeventfd trigger cleanup. While there, move the "invalid" peer check to the only caller where it can actually happen, and tighten it to reject own ID. Cc: Paolo Bonzini Signed-off-by: Markus Armbruster Reviewed-by: Marc-André Lureau --- hw/misc/ivshmem.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index d8d363e..c6d5dd5 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -428,21 +428,17 @@ static void close_peer_eventfds(IVShmemState *s, int posn) { int i, n; - if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { - return; - } - if (posn < 0 || posn >= s->nb_peers) { - error_report("invalid peer %d", posn); - return; - } - + assert(posn >= 0 && posn < s->nb_peers); n = s->peers[posn].nb_eventfds; - memory_region_transaction_begin(); - for (i = 0; i < n; i++) { - ivshmem_del_eventfd(s, posn, i); + if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) { + memory_region_transaction_begin(); + for (i = 0; i < n; i++) { + ivshmem_del_eventfd(s, posn, i); + } + memory_region_transaction_commit(); } - memory_region_transaction_commit(); + for (i = 0; i < n; i++) { event_notifier_cleanup(&s->peers[posn].eventfds[i]); } @@ -598,6 +594,10 @@ static void process_msg_shmem(IVShmemState *s, int fd) static void process_msg_disconnect(IVShmemState *s, uint16_t posn) { IVSHMEM_DPRINTF("posn %d has gone away\n", posn); + if (posn >= s->nb_peers || posn == s->vm_id) { + error_report("invalid peer %d", posn); + return; + } close_peer_eventfds(s, posn); }