Re: - maps2-add-proc-pid-pagemap-interface-fix.patch removed from -mm tree

[Matt Mackall]

On Fri, Apr 27, 2007 at 01:27:13PM -0700, Andrew Morton wrote:
> On Fri, 27 Apr 2007 14:45:33 +0400
> Alexey Dobriyan <adobriyan@xxxxx> wrote:
> 
> > > maps2-add-proc-pid-pagemap-interface.patch
> > 
> > Ohhh, you're repeating december mincore() bug
> > 2f77d107050abc14bc393b34bdb7b91cf670c250
> > 
> > pagemap_read() takes ->mmap_sem for reading
> > walk_page_range
> > pagemap_pte_range
> > add_to_pagemap
> > flush_pagemap
> > copy_to_user
> 
> argh.  I think it's always a bug to run uaccess functions while holding
> mmap_sem, isn't it?

Yep, looks that way.

> I'll see if I can get something like this working as a -mm-only thing:

I was wondering if there was a sensible way to do this. This looks
pretty good.
 
> +	no+_mmap_sem();						\

Except for this bit. Maybe put it in the same config bucket as might_sleep?

-- 
Mathematics is the supreme nostalgia of our time.
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