From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Guenter Roeck <linux@roeck-us.net>
Cc: linux-usb <linux-usb@vger.kernel.org>,
"linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>
Subject: Re: usb_control_msg and non-dma buffers
Date: Mon, 14 Oct 2013 08:53:10 -0700 [thread overview]
Message-ID: <20131014155310.GA3474@kroah.com> (raw)
In-Reply-To: <525C1218.7060901@roeck-us.net>
On Mon, Oct 14, 2013 at 08:47:36AM -0700, Guenter Roeck wrote:
> Hi all,
>
> I am getting the following smatch error in drivers/watchdog/pcwd_usb.c:
>
> drivers/watchdog/pcwd_usb.c:257 usb_pcwd_send_command() error: doing dma on the stack (buf)
>
> This is from a call to usb_control_msg().
>
> Is this a false positive or a real problem that needs to be fixed ?
It is a real problem that must be fixed.
You can't send USB data off of the stack and expect the driver to work
on all controllers and platforms.
thanks,
greg k-h
prev parent reply other threads:[~2013-10-14 15:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-14 15:47 usb_control_msg and non-dma buffers Guenter Roeck
2013-10-14 15:53 ` Greg Kroah-Hartman [this message]
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