From patchwork Mon Mar 21 20:43:45 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 600333 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3qTSh30CsPz9s2k for ; Tue, 22 Mar 2016 07:52:35 +1100 (AEDT) Received: from localhost ([::1]:60292 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ai6oT-0007Sb-9N for incoming@patchwork.ozlabs.org; Mon, 21 Mar 2016 16:52:33 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48715) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ai6gR-0000QK-DM for qemu-devel@nongnu.org; Mon, 21 Mar 2016 16:44:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ai6gO-0000n2-0O for qemu-devel@nongnu.org; Mon, 21 Mar 2016 16:44:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36603) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ai6gN-0000mO-NT for qemu-devel@nongnu.org; Mon, 21 Mar 2016 16:44:11 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (Postfix) with ESMTPS id 573958E248 for ; Mon, 21 Mar 2016 20:44:11 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-116-41.ams2.redhat.com [10.36.116.41]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u2LKi9bR021972 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Mon, 21 Mar 2016 16:44:10 -0400 Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id F1ED23005315; Mon, 21 Mar 2016 21:44:04 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Date: Mon, 21 Mar 2016 21:43:45 +0100 Message-Id: <1458593043-31731-23-git-send-email-armbru@redhat.com> In-Reply-To: <1458593043-31731-1-git-send-email-armbru@redhat.com> References: <1458593043-31731-1-git-send-email-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v2 22/40] ivshmem: Simplify rejection of invalid peer ID from server 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org ivshmem_read() processes server messages. These are 64 bit signed integers. -1 is shared memory setup, 16 bit unsigned is a peer ID, anything else is invalid. ivshmem_read() rejects invalid negative messages right away, silently. Invalid positive messages get rejected only in resize_peers(), and ivshmem_read() then prints the rather cryptic message "failed to resize peers array". Extend the first check to cover all invalid messages, make it report "server sent invalid message", and drop the second check. Now resize_peers() can't fail anymore; simplify. Signed-off-by: Markus Armbruster Reviewed-by: Marc-André Lureau Message-Id: <1458066895-20632-23-git-send-email-armbru@redhat.com> --- hw/misc/ivshmem.c | 61 ++++++++++++++++++++----------------------------------- 1 file changed, 22 insertions(+), 39 deletions(-) diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c index 61e21cd..703b3bf 100644 --- a/hw/misc/ivshmem.c +++ b/hw/misc/ivshmem.c @@ -39,7 +39,7 @@ #define PCI_VENDOR_ID_IVSHMEM PCI_VENDOR_ID_REDHAT_QUMRANET #define PCI_DEVICE_ID_IVSHMEM 0x1110 -#define IVSHMEM_MAX_PEERS G_MAXUINT16 +#define IVSHMEM_MAX_PEERS UINT16_MAX #define IVSHMEM_IOEVENTFD 0 #define IVSHMEM_MSI 1 @@ -93,7 +93,7 @@ typedef struct IVShmemState { uint32_t ivshmem_64bit; Peer *peers; - int nb_peers; /* how many peers we have space for */ + int nb_peers; /* space in @peers[] */ int vm_id; uint32_t vectors; @@ -451,34 +451,21 @@ static void close_peer_eventfds(IVShmemState *s, int posn) s->peers[posn].nb_eventfds = 0; } -/* this function increase the dynamic storage need to store data about other - * peers */ -static int resize_peers(IVShmemState *s, int new_min_size) +static void resize_peers(IVShmemState *s, int nb_peers) { + int old_nb_peers = s->nb_peers; + int i; - int j, old_size; + assert(nb_peers > old_nb_peers); + IVSHMEM_DPRINTF("bumping storage to %d peers\n", nb_peers); - /* limit number of max peers */ - if (new_min_size <= 0 || new_min_size > IVSHMEM_MAX_PEERS) { - return -1; - } - if (new_min_size <= s->nb_peers) { - return 0; - } - - old_size = s->nb_peers; - s->nb_peers = new_min_size; + s->peers = g_realloc(s->peers, nb_peers * sizeof(Peer)); + s->nb_peers = nb_peers; - IVSHMEM_DPRINTF("bumping storage to %d peers\n", s->nb_peers); - - s->peers = g_realloc(s->peers, s->nb_peers * sizeof(Peer)); - - for (j = old_size; j < s->nb_peers; j++) { - s->peers[j].eventfds = g_new0(EventNotifier, s->vectors); - s->peers[j].nb_eventfds = 0; + for (i = old_nb_peers; i < nb_peers; i++) { + s->peers[i].eventfds = g_new0(EventNotifier, s->vectors); + s->peers[i].nb_eventfds = 0; } - - return 0; } static bool fifo_update_and_get(IVShmemState *s, const uint8_t *buf, int size, @@ -590,25 +577,21 @@ static void ivshmem_read(void *opaque, const uint8_t *buf, int size) return; } - if (incoming_posn < -1) { - IVSHMEM_DPRINTF("invalid incoming_posn %" PRId64 "\n", incoming_posn); - return; - } - - /* pick off s->server_chr->msgfd and store it, posn should accompany msg */ incoming_fd = qemu_chr_fe_get_msgfd(s->server_chr); IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", incoming_posn, incoming_fd); - /* make sure we have enough space for this peer */ + if (incoming_posn < -1 || incoming_posn > IVSHMEM_MAX_PEERS) { + error_report("server sent invalid message %" PRId64, + incoming_posn); + if (incoming_fd != -1) { + close(incoming_fd); + } + return; + } + if (incoming_posn >= s->nb_peers) { - if (resize_peers(s, incoming_posn + 1) < 0) { - error_report("failed to resize peers array"); - if (incoming_fd != -1) { - close(incoming_fd); - } - return; - } + resize_peers(s, incoming_posn + 1); } peer = &s->peers[incoming_posn];