From patchwork Wed Oct 26 21:22:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9398349 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8AA5F600BA for ; Wed, 26 Oct 2016 21:23:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 557AB29E13 for ; Wed, 26 Oct 2016 21:23:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4A21529E16; Wed, 26 Oct 2016 21:23:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 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.wl.linuxfoundation.org (Postfix) with ESMTPS id 480A129E13 for ; Wed, 26 Oct 2016 21:23:01 +0000 (UTC) Received: from localhost ([::1]:37458 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bzVf2-0006Mi-GG for patchwork-qemu-devel@patchwork.kernel.org; Wed, 26 Oct 2016 17:23:00 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51244) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bzVeg-0006LH-AJ for qemu-devel@nongnu.org; Wed, 26 Oct 2016 17:22:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bzVef-0000JO-CW for qemu-devel@nongnu.org; Wed, 26 Oct 2016 17:22:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59366) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1bzVea-0000GU-MA; Wed, 26 Oct 2016 17:22:32 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B7D2B8F278; Wed, 26 Oct 2016 21:22:31 +0000 (UTC) Received: from javelin.localdomain (vpn-55-145.rdu2.redhat.com [10.10.55.145]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u9QLMQFF013938 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 26 Oct 2016 17:22:28 -0400 From: P J P To: Qemu Developers Date: Thu, 27 Oct 2016 02:52:25 +0530 Message-Id: <1477516945-9891-1-git-send-email-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 26 Oct 2016 21:22:31 +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 v3] char: cadence: check baud rate generator and divider values 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: Peter Maydell , Prasad J Pandit , Alistair Francis , qemu-arm , "Edgar E . Iglesias" , Huawei PSIRT Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit The Cadence UART device emulator calculates speed by dividing the baud rate by a 'baud rate generator' & 'baud rate divider' value. The device specification defines these register values to be non-zero and within certain limits. Add checks for these limits to avoid errors like divide by zero. Reported-by: Huawei PSIRT Signed-off-by: Prasad J Pandit --- hw/char/cadence_uart.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) Update: mask R_BRGR and R_BDIV register values with 0xffff and 0xff resp. -> https://lists.gnu.org/archive/html/qemu-devel/2016-10/msg06206.html -> https://lists.gnu.org/archive/html/qemu-devel/2016-10/msg06215.html diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c index e3bc52f..5341d81 100644 --- a/hw/char/cadence_uart.c +++ b/hw/char/cadence_uart.c @@ -1,5 +1,10 @@ /* * Device model for Cadence UART + * -> http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf + * + * Reference: Xilinx Zynq 7000 reference manual + * - Chapter 19 UART Controller + * - Appendix B for Register details * * Copyright (c) 2010 Xilinx Inc. * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com) @@ -410,6 +415,18 @@ static void uart_write(void *opaque, hwaddr offset, break; } break; + case R_BRGR: /* Baud rate generator */ + s->r[offset] = 0x028B; /* default reset value */ + if (value >= 0x01) { + s->r[offset] = value & 0xFFFF; + } + break; + case R_BDIV: /* Baud rate divider */ + s->r[offset] = 0x0F; + if (value >= 0x04) { + s->r[offset] = value & 0xFF; + } + break; default: s->r[offset] = value; }