From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50609) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5Dfm-0002u4-KT for qemu-devel@nongnu.org; Wed, 17 Jun 2015 09:46:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z5Dfg-0001kT-7q for qemu-devel@nongnu.org; Wed, 17 Jun 2015 09:46:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33752) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z5Dfg-0001kP-2o for qemu-devel@nongnu.org; Wed, 17 Jun 2015 09:46:28 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (Postfix) with ESMTPS id AF1228E4F7 for ; Wed, 17 Jun 2015 13:46:27 +0000 (UTC) Date: Wed, 17 Jun 2015 15:46:24 +0200 From: "Michael S. Tsirkin" Message-ID: <20150617154603-mutt-send-email-mst@redhat.com> References: <1434545105-5811-1-git-send-email-lersek@redhat.com> <1434545105-5811-6-git-send-email-lersek@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1434545105-5811-6-git-send-email-lersek@redhat.com> Subject: Re: [Qemu-devel] [PATCH v6 5/7] hw/core: rebase sysbus_get_fw_dev_path() to g_strdup_printf() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laszlo Ersek Cc: Marcel Apfelbaum , qemu-devel@nongnu.org, Markus Armbruster On Wed, Jun 17, 2015 at 02:45:03PM +0200, Laszlo Ersek wrote: > 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 In fact, I'd Cc stable on this one. > --- > > 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, > -- > 1.8.3.1 >