Commit e53ac737 authored by Rik van Riel's avatar Rik van Riel Committed by Linus Torvalds

mm: invalidate hwpoison page cache page in fault path

Sometimes the page offlining code can leave behind a hwpoisoned clean
page cache page.  This can lead to programs being killed over and over
and over again as they fault in the hwpoisoned page, get killed, and
then get re-spawned by whatever wanted to run them.

This is particularly embarrassing when the page was offlined due to
having too many corrected memory errors.  Now we are killing tasks due
to them trying to access memory that probably isn't even corrupted.

This problem can be avoided by invalidating the page from the page fault
handler, which already has a branch for dealing with these kinds of
pages.  With this patch we simply pretend the page fault was successful
if the page was invalidated, return to userspace, incur another page
fault, read in the file from disk (to a new memory page), and then
everything works again.

Link: https://lkml.kernel.org/r/20220212213740.423efcea@imladris.surriel.comSigned-off-by: default avatarRik van Riel <riel@surriel.com>
Reviewed-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Acked-by: default avatarNaoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: default avatarOscar Salvador <osalvador@suse.de>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 046545a6
......@@ -3877,11 +3877,16 @@ static vm_fault_t __do_fault(struct vm_fault *vmf)
return ret;
if (unlikely(PageHWPoison(vmf->page))) {
if (ret & VM_FAULT_LOCKED)
vm_fault_t poisonret = VM_FAULT_HWPOISON;
if (ret & VM_FAULT_LOCKED) {
/* Retry if a clean page was removed from the cache. */
if (invalidate_inode_page(vmf->page))
poisonret = 0;
unlock_page(vmf->page);
}
put_page(vmf->page);
vmf->page = NULL;
return VM_FAULT_HWPOISON;
return poisonret;
}
if (unlikely(!(ret & VM_FAULT_LOCKED)))
......
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