Re: [PATCH] bitmap: separate bitmap parsing for user buffer and kernel buffer

From: Inaky Perez-Gonzalez
Date: Wed Oct 04 2006 - 21:34:04 EST


On Wednesday 04 October 2006 18:10, Andrew Morton wrote:
> On Wed, 4 Oct 2006 17:56:30 -0700
> Reinette Chatre <reinette.chatre@xxxxxxxxxxxxxxx> wrote:
> > + if (is_user) {
> > + if (__get_user(c, buf++))
> > + return -EFAULT;
> > + }
> > + else
> > + c = *buf++;
>
> Is this actually needed? __get_user(kernel_address) works OK and (believe
> it or not, given all the stuff it involves) boils down to a single
> instruction.

We weren't too sure if that'd be true in all kinds of arches and
memory models. If it works for kernel space too, then we can fold
out a lot of code...

Your call, you are the expert :)

--
Inaky
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