From mboxrd@z Thu Jan 1 00:00:00 1970 From: walter harms Date: Fri, 08 May 2015 11:13:22 +0000 Subject: Re: [patch v2] virtio_console: silence a static checker warning Message-Id: <554C9A52.4030707@bfs.de> List-Id: References: <20150508091624.GS14154@mwanda> In-Reply-To: <20150508091624.GS14154@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kernel-janitors@vger.kernel.org Am 08.05.2015 11:56, schrieb Amit Shah: > On (Fri) 08 May 2015 [11:30:09], walter harms wrote: >> >> >> Am 08.05.2015 11:16, schrieb Dan Carpenter: >>> My static checker complains that this sprintf() can overflow but really >>> it can't. Just silence the warning by using snprintf(). >>> >>> Signed-off-by: Dan Carpenter >>> --- >>> v2: the overflow is not possible so just leave the buffer size alone and >>> silence the warning with snprintf(). >>> >>> diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c >>> index 50754d20..8283989 100644 >>> --- a/drivers/char/virtio_console.c >>> +++ b/drivers/char/virtio_console.c >>> @@ -1492,8 +1492,8 @@ static int add_port(struct ports_device *portdev, u32 id) >>> * Finally, create the debugfs file that we can use to >>> * inspect a port's state at any time >>> */ >>> - sprintf(debugfs_name, "vport%up%u", >>> - port->portdev->vdev->index, id); >>> + snprintf(debugfs_name, sizeof(debugfs_name), "vport%up%u", >>> + port->portdev->vdev->index, id); >> >> >> would it help to use %03u (or so) to make it more obvious ? >> >> Note: i prefer a leading 0 in my programms to make it more easy >> to work with grep and friends. you may thing otherwise. > > Well we've been exposing names like /dev/vport0p0, /dev/vport2p15, > etc., and there might be scripts relying on such names, so that's one > argument against it. > > However we do have pretty names that map to these ports via udev > rules, but not sure if we should change the name just to prepend 0s. > > Amit > The basic idea was to limit the space, having leading zeros is my idea because i found this more convenient in the past. Using something like "%3u" will give static checkers a chance to detect the required max. space. re, wh