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Date: Wed, 4 Oct 2006 10:57:15 -0700 (PDT)
Subject: Re: [PATCH] bitmap: bitmap_parse takes a kernel buffer instead of 
     a user buffer
From: "Inaky Perez-Gonzalez" <inaky@linux.intel.com>
To: "Joe Korty" <joe.korty@ccur.com>
Cc: "Andrew Morton" <akpm@osdl.org>,
       "Reinette Chatre" <reinette.chatre@linux.intel.com>,
       linux-kernel@vger.kernel.org,
       "Inaky Perez-Gonzalez" <inaky@linux.intel.com>,
       "Paul Jackson" <pj@sgi.com>
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Joe Korty wrote:
> On Wed, Oct 04, 2006 at 09:40:29AM -0700, Andrew Morton wrote:
>> I think we can do a version which omits the kmalloc altogether:
>
>> 			if (__get_user(c, ubuf++))
>> 				return -EFAULT;
>>
>> (Note the s/get_user/__get_user/)
>
> Nice.  This eliminates the bulk of the get_user() overhead.  And
> it can be merged into Inaky's enum solution too, for something
> that is both simple and efficient.

Then bitmap_parse_user() will need a quick access_ok() check
before calling down on __bitmap_parse(). Nice.

-- 
Inaky
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