Re: [PATCH] usb: use memdup_user()

From: Li Hong <lihong.hi@gmail.com>
To: Oliver Neukum <oliver@neukum.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] usb: use memdup_user()
Date: Sun, 3 May 2009 23:38:33 -0400	[thread overview]
Message-ID: <3a3680030905032038h40cd75bdrbee839117e5a4d55@mail.gmail.com> (raw)
In-Reply-To: <200905031909.14101.oliver@neukum.org>

The key is: is there any need or probability to use GFP_NOIO instead
of GFP_KERNEL _here_? It also confuses me to move the user space copy
outside of the loop.

IMHO, this is just a simple cleanup of the code.

Regards,
Hong

2009/5/3 Oliver Neukum <oliver@neukum.org>:
> Am Sonntag, 3. Mai 2009 18:00:56 schrieb Li Hong:
>> Replace a combination call of kmalloc() and copy_from_user() with
>> memdup_user().
>
> To be precise. copy_*_user() of course implies that you can do
> GFP_KERNEL. But the point is one of design. Right now I can change
> locking and if that means that one must use GFP_NOIO, which is common
> in usb due to the storage driver, we can find out by simply grepping and
> move the user space copy outside of the loop.
>
> If you make that change we must grep against a second and rare
> key.
>
>        Regards
>                Oliver
>
>