Re: [GIT PULL] aio: changes for 3.19

[Benjamin LaHaise]

On Mon, Dec 15, 2014 at 01:02:08AM +0200, Kirill A. Shutemov wrote:
> But it seems the problem is bigger than what the patch fixes. To me we are
> too permisive on what vma can be remapped.
> 
> How can we know that it's okay to move vma around for random driver which
> provide .mmap? Or I miss something obvious?

Most drivers do not care if a vma is moved within the virtual address space 
of a process.  The aio ring buffer is special in that it gets unmapped when 
userspace does an io_destroy(), and io_destroy() has to know what the address 
is moved to in order to perform the unmap.  Normal drivers don't perform the 
unmap themselves.

		-ben
-- 
"Thought is the essence of where you are now."
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