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
