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
