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Date: Mon, 12 Aug 2002 10:30:25 -0700 (PDT)
From: Linus Torvalds <torvalds@transmeta.com>
To: Rusty Russell <rusty@rustcorp.com.au>
cc: akpm@zip.com.au, <linux-kernel@vger.kernel.org>
Subject: Re: [patch 6/12] hold atomic kmaps across generic_file_read
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On Mon, 12 Aug 2002, Rusty Russell wrote:
> On Fri, 9 Aug 2002 18:33:09 -0700 (PDT)
> Linus Torvalds <torvalds@transmeta.com> wrote:
> 
> > 	repeat:
> > 		kmap_atomic(..); // this increments preempt count
> > 		nr = copy_from_user(..);
> 
> Please please please use a different name for "I know I'm not preemptible but
> I can handle it" or a flag or something.
> 
> That leaves us with the possibility of a BUG() in the "normal" copy_to/from_user
> for all those "I'm holding a spinlock while copying to userspace wheeee!" bugs.
> Very common mistake for new kernel authors.

Agreed. 

Maybe the right thing to do is to just have a 

	atomic_copy_from_user()

which can then be used to explicitly not check if we have a kernel 
debugging option.

		Linus

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