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To: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <a.p.zijlstra@chello.nl>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [patch] x86: some lock annotations for user copy paths
From: Andi Kleen <andi@firstfloor.org>
References: <20080910113717.GB16811@wotan.suse.de>
Date: Wed, 10 Sep 2008 16:31:15 +0200
In-Reply-To: <20080910113717.GB16811@wotan.suse.de> (Nick Piggin's message of "Wed, 10 Sep 2008 13:37:17 +0200")
Message-ID: <87od2wrs24.fsf@basil.nowhere.org>
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Nick Piggin <npiggin@suse.de> writes:
>  int __copy_from_user(void *dst, const void __user *src, unsigned size)
>  {
>  	int ret = 0;
> +
> +	might_sleep();
> +	if (current->mm)
> +		might_lock_read(&current->mm->mmap_sem);

It would be nicer if you defined a standard function for this, e.g.
a might_page_fault(); 

This would also make it easier to potentially add more locks.

-Andi

-- 
ak@linux.intel.com