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Date: Tue, 22 Mar 2005 05:47:13 +0000 (GMT)
From: Hugh Dickins <hugh@veritas.com>
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To: "David S. Miller" <davem@davemloft.net>
cc: akpm@osdl.org, nickpiggin@yahoo.com.au, tony.luck@intel.com,
       benh@kernel.crashing.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] freepgt: free_pgtables use vma list
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On Mon, 21 Mar 2005, David S. Miller wrote:
> 
> flush_tlb_pgtables() on sparc64 has a BUG() check which
> is basically:
> 
> 	BUG((long)start > (long)end);
> 
> This catches two cases of bogus arguments:
> 
> 1) start --> end straddles sparc64 address space hole

That's an interesting remark.  I hadn't noticed the signed long type.
I believe the vma gathering in free_pgtables will have no problem with
that, but what about the old code?  What happens if an app does a huge
munmap straddling the address space hole?  Or is all the user address
space below the hole?

Hugh