Messages in this thread | | | Date | Wed, 13 Oct 2021 10:49:04 +0800 | From | Peter Xu <> | Subject | Re: [PATCH v1] mm, pagemap: expose hwpoison entry |
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Hi, Naoya,
On Mon, Oct 04, 2021 at 08:50:01PM +0900, Naoya Horiguchi wrote: > +static inline struct page *hwpoison_entry_to_page(swp_entry_t entry) > +{ > + struct page *p = pfn_to_page(swp_offset(entry)); > + > + WARN_ON(!PageHWPoison(p)); > + return p; > +}
This is more a pure question..
I'm wondering whether that WARN_ON() could trigger.
IOW, what if we poison an anonymous page and then unpoison it? Will there be a hwpoison swap entry leftover in the ptes that it used to map? Will it crash the program when the page is accessed?
I had a feeling that when handling the page fault in do_swap_page before we SIGBUS the program, we should double-check the PageHWPoison on the pfn page, but I could be missing something..
Thanks,
-- Peter Xu
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