From: Maksim Salau <maksim.salau@gmail.com>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: linux-kernel@vger.kernel.org, arnd@arndb.de,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alan Stern <stern@rowland.harvard.edu>,
Mathias Nyman <mathias.nyman@linux.intel.com>,
Peter Chen <peter.chen@nxp.com>, Roger Quadros <rogerq@ti.com>,
Baoyou Xie <baoyou.xie@linaro.org>, Sekhar Nori <nsekhar@ti.com>,
Chris Bainbridge <chris.bainbridge@gmail.com>,
Wolfram Sang <wsa-dev@sang-engineering.com>,
linux-usb@vger.kernel.org (open list:USB SUBSYSTEM)
Subject: Re: [PATCH v2] usb: core: Warn if an URB's transfer_buffer is on stack
Date: Tue, 25 Apr 2017 13:35:33 +0300 [thread overview]
Message-ID: <20170425133533.52ba1cb6@gmail.com> (raw)
In-Reply-To: <20170424012939.29929-1-f.fainelli@gmail.com>
> + } else if (object_is_on_stack(urb->transfer_buffer)) {
> + WARN_ONCE(1, "transfer buffer is on stack\n");
> + ret = -EAGAIN;
> } else {
Hi,
Has anyone considered a fail-safe mode? I.e.: if a buffer is on stack,
kmemdup it and continue with a warning. This will give us both: functional
drivers (with possibly decreased efficiency in speed and memory footprint)
and warnings for developers that a particular driver requires attention.
This mode will not affect drivers which obey the rules, but will make
offenders at least functional. My main concern is that not every user is able
to detect and report a problem, which prevents drivers from functioning.
Especially this is a problem for not wide spread devices.
Due to this users a seeing unusable equipment, but developers are not
aware of those, even if fixes are trivial.
Such mode has a also a negative effect: if a developer has a device
with an offending driver, he can miss the warning message, since the driver
just works.
Regards,
Maksim.
next prev parent reply other threads:[~2017-04-25 10:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-24 1:29 [PATCH v2] usb: core: Warn if an URB's transfer_buffer is on stack Florian Fainelli
2017-04-24 7:15 ` Clemens Ladisch
2017-04-24 13:27 ` Alan Stern
2017-04-25 10:35 ` Maksim Salau [this message]
2017-04-25 11:37 ` Greg Kroah-Hartman
2017-04-25 13:27 ` Felipe Balbi
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