From patchwork Wed Jun 17 12:45:03 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laszlo Ersek X-Patchwork-Id: 485382 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 685BA1401F0 for ; Wed, 17 Jun 2015 22:47:13 +1000 (AEST) Received: from localhost ([::1]:46558 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5CkJ-0003iZ-Lq for incoming@patchwork.ozlabs.org; Wed, 17 Jun 2015 08:47:11 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55389) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5Cia-0001wP-BO for qemu-devel@nongnu.org; Wed, 17 Jun 2015 08:45:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5CiZ-0000CF-76 for qemu-devel@nongnu.org; Wed, 17 Jun 2015 08:45:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35931) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5CiZ-0000CB-2G for qemu-devel@nongnu.org; Wed, 17 Jun 2015 08:45:23 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (Postfix) with ESMTPS id AC18C2DC3F4 for ; Wed, 17 Jun 2015 12:45:22 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com ([10.10.116.42]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t5HCjBRw007141; Wed, 17 Jun 2015 08:45:21 -0400 From: Laszlo Ersek To: qemu-devel@nongnu.org, lersek@redhat.com Date: Wed, 17 Jun 2015 14:45:03 +0200 Message-Id: <1434545105-5811-6-git-send-email-lersek@redhat.com> In-Reply-To: <1434545105-5811-1-git-send-email-lersek@redhat.com> References: <1434545105-5811-1-git-send-email-lersek@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Marcel Apfelbaum , Markus Armbruster , "Michael S. Tsirkin" Subject: [Qemu-devel] [PATCH v6 5/7] hw/core: rebase sysbus_get_fw_dev_path() to g_strdup_printf() 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 This is done mainly for improving readability, and in preparation for the next patch, but Markus pointed out another bonus for the string being returned: "No arbitrary length limit. Before the patch, it's 39 characters, and the code breaks catastrophically when qdev_fw_name() is longer: the second snprintf() is called with its first argument pointing beyond path[], and its second argument underflowing to a huge size." Cc: Markus Armbruster Cc: Marcel Apfelbaum Cc: Michael S. Tsirkin Signed-off-by: Laszlo Ersek Tested-by: Marcel Apfelbaum Reviewed-by: Marcel Apfelbaum Reviewed-by: Markus Armbruster Reviewed-by: Michael S. Tsirkin --- Notes: v6: - no changes v5: - separate "%s@" from TARGET_FMT_plx with a space [Markus] - copied Markus's note about "no arbitrary length limit" on the retval into the commit message v4: - unchanged v3: - new in v3 hw/core/sysbus.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/hw/core/sysbus.c b/hw/core/sysbus.c index b53c351..92eced9 100644 --- a/hw/core/sysbus.c +++ b/hw/core/sysbus.c @@ -281,19 +281,15 @@ static void sysbus_dev_print(Monitor *mon, DeviceState *dev, int indent) static char *sysbus_get_fw_dev_path(DeviceState *dev) { SysBusDevice *s = SYS_BUS_DEVICE(dev); - char path[40]; - int off; - - off = snprintf(path, sizeof(path), "%s", qdev_fw_name(dev)); if (s->num_mmio) { - snprintf(path + off, sizeof(path) - off, "@"TARGET_FMT_plx, - s->mmio[0].addr); - } else if (s->num_pio) { - snprintf(path + off, sizeof(path) - off, "@i%04x", s->pio[0]); + return g_strdup_printf("%s@" TARGET_FMT_plx, qdev_fw_name(dev), + s->mmio[0].addr); } - - return g_strdup(path); + if (s->num_pio) { + return g_strdup_printf("%s@i%04x", qdev_fw_name(dev), s->pio[0]); + } + return g_strdup(qdev_fw_name(dev)); } void sysbus_add_io(SysBusDevice *dev, hwaddr addr,