Both collect_procs_anon() and collect_procs_file() iterate over the VMA interval trees looking for a single pgoff, so it is wrong to look for the pgoff of the head page as is currently done. However, it is also wrong to look at page->mapping of the precise page as this is invalid for tail pages. Clear up the confusion by passing both the folio and the precise page to collect_procs().

Fixes: 415c64c1453a ("mm/memory-failure: split thp earlier in memory error handling") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org --- mm/memory-failure.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 660c21859118..6953bda11e6e 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -595,10 +595,9 @@ struct task_struct *task_early_kill(struct task_struct *tsk, int force_early) /* * Collect processes when the error hit an anonymous page. */ -static void collect_procs_anon(struct page *page, struct list_head *to_kill, - int force_early) +static void collect_procs_anon(struct folio *folio, struct page *page, + struct list_head *to_kill, int force_early) { - struct folio *folio = page_folio(page); struct vm_area_struct *vma; struct task_struct *tsk; struct anon_vma *av; @@ -633,12 +632,12 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, /* * Collect processes when the error hit a file mapped page. */ -static void collect_procs_file(struct page *page, struct list_head *to_kill, - int force_early) +static void collect_procs_file(struct folio *folio, struct page *page, + struct list_head *to_kill, int force_early) { struct vm_area_struct *vma; struct task_struct *tsk; - struct address_space *mapping = page->mapping; + struct address_space *mapping = folio->mapping; pgoff_t pgoff;

i_mmap_lock_read(mapping); @@ -704,17 +703,17 @@ static void collect_procs_fsdax(struct page *page, /* * Collect the processes who have the corrupted page mapped to kill. */ -static void collect_procs(struct page *page, struct list_head *tokill, - int force_early) +static void collect_procs(struct folio *folio, struct page *page, + struct list_head *tokill, int force_early) { - if (!page->mapping) + if (!folio->mapping) return; if (unlikely(PageKsm(page))) collect_procs_ksm(page, tokill, force_early); else if (PageAnon(page)) - collect_procs_anon(page, tokill, force_early); + collect_procs_anon(folio, page, tokill, force_early); else - collect_procs_file(page, tokill, force_early); + collect_procs_file(folio, page, tokill, force_early); }

struct hwpoison_walk { @@ -1602,7 +1601,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn, * mapped in dirty form. This has to be done before try_to_unmap, * because ttu takes the rmap data structures down. */ - collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED); + collect_procs(folio, p, &tokill, flags & MF_ACTION_REQUIRED);

if (PageHuge(hpage) && !PageAnon(hpage)) { /* @@ -1772,7 +1771,7 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags, * SIGBUS (i.e. MF_MUST_KILL) */ flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; - collect_procs(&folio->page, &to_kill, true); + collect_procs(folio, &folio->page, &to_kill, true);

unmap_and_kill(&to_kill, pfn, folio->mapping, folio->index, flags); unlock: