Messages in this thread | | | Subject | Re: [PATCH v5] mm/gup: check page hwposion status for coredump. | From | David Hildenbrand <> | Date | Wed, 31 Mar 2021 09:05:06 +0200 |
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On 31.03.21 08:53, HORIGUCHI NAOYA(堀口 直也) wrote: > On Wed, Mar 31, 2021 at 07:07:39AM +0100, Matthew Wilcox wrote: >> On Wed, Mar 31, 2021 at 01:52:59AM +0000, HORIGUCHI NAOYA(堀口 直也) wrote: >>> If we successfully unmapped but failed in truncate_error_page() for example, >>> the processes mapping the page would get -EFAULT as expected. But even in >>> this case, other processes could reach the error page via page cache and >>> __get_user_pages_locked() for them could return the hwpoisoned page. >> >> How would that happen? We check PageHWPoison before inserting a page >> into the page tables. See, eg, filemap_map_pages() and __do_fault(). > > Ah, you're right, that never happens. I misread the code. > Thanks for correcting me. >
I'm wondering if there is a small race window, if we poison a page while inserting it.
-- Thanks,
David / dhildenb
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