mm, hwpoison: kill procs if unmap fails
If try_to_unmap() fails, the hwpoisoned page still resides in the address
space of some processes. We should kill these processes or the hwpoisoned
page might be consumed later. collect_procs() is always called to collect
relevant processes now so they can be killed later if unmap fails.
[linmiaohe@huawei.com: v2]
Link: https://lkml.kernel.org/r/20220823032346.4260-6-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220818130016.45313-6-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 208a0f8..3b8e793 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1397,7 +1397,7 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
struct address_space *mapping;
LIST_HEAD(tokill);
bool unmap_success;
- int kill = 1, forcekill;
+ int forcekill;
bool mlocked = PageMlocked(hpage);
/*
@@ -1438,7 +1438,6 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
if (page_mkclean(hpage)) {
SetPageDirty(hpage);
} else {
- kill = 0;
ttu |= TTU_IGNORE_HWPOISON;
pr_info("%#lx: corrupted page was clean: dropped without side effects\n",
pfn);
@@ -1449,12 +1448,8 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
* First collect all the processes that have the page
* mapped in dirty form. This has to be done before try_to_unmap,
* because ttu takes the rmap data structures down.
- *
- * Error handling: We ignore errors here because
- * there's nothing that can be done.
*/
- if (kill)
- collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
+ collect_procs(hpage, &tokill, flags & MF_ACTION_REQUIRED);
if (PageHuge(hpage) && !PageAnon(hpage)) {
/*
@@ -1496,7 +1491,8 @@ static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
* use a more force-full uncatchable kill to prevent
* any accesses to the poisoned memory.
*/
- forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL);
+ forcekill = PageDirty(hpage) || (flags & MF_MUST_KILL) ||
+ !unmap_success;
kill_procs(&tokill, forcekill, !unmap_success, pfn, flags);
return unmap_success;
