Messages in this thread | | | Date | Mon, 17 Dec 2007 13:41:06 +0000 | From | "Jan Beulich" <> | Subject | Re: [PATCH] x86: fix ref-counting bug in change_page_attr() |
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>>> Ingo Molnar <mingo@elte.hu> 17.12.07 14:28 >>> > >* Jan Beulich <jbeulich@novell.com> wrote: > >> When either calling change_page_attr() with the default attributes >> pages in the direct mapping have and a page's attributes already were >> set to the default or when changing the attributes from one >> non-default value to another, the reference counting broke, leading to >> either premature restoration of a large page or missing the >> opportunity to do so. >> >> At the same time, make __PHYSICAL_MASK_SHIFT on 64-bits the value it >> architecturally ought to have. > >hm, does this patch fix any real bug seen live? (if yes then do you have >links to it, etc?) It would be a v2.6.24 fix in theory but it looks too >dangerous for that. So i've queued it up for v2.6.25, for the time >being.
I had run into the issue with experimental code of mine quite a while back (i.e. I don't even recall what exactly I was doing back then). After that I just continued to keep the fix (which I had submitted before, but which collided with something in Andi's tree back then iirc).
Jan
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