From: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Subject: mm,hwpoison-inject: don't pin for hwpoison_filter Another memory error injection interface debugfs:hwpoison/corrupt-pfn also takes bogus refcount for hwpoison_filter(). It's justified because this does a coarse filter, expecting that memory_failure() redoes the check for sure. Link: https://lkml.kernel.org/r/20200922135650.1634-4-osalvador@xxxxxxx Signed-off-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx> Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Aristeu Rozanski <aris@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Dmitry Yakunin <zeil@xxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Oscar Salvador <osalvador@xxxxxxxx> Cc: Qian Cai <cai@xxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hwpoison-inject.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) --- a/mm/hwpoison-inject.c~mmhwpoison-inject-dont-pin-for-hwpoison_filter +++ a/mm/hwpoison-inject.c @@ -26,11 +26,6 @@ static int hwpoison_inject(void *data, u p = pfn_to_page(pfn); hpage = compound_head(p); - /* - * This implies unable to support free buddy pages. - */ - if (!get_hwpoison_page(p)) - return 0; if (!hwpoison_filter_enable) goto inject; @@ -40,23 +35,20 @@ static int hwpoison_inject(void *data, u * This implies unable to support non-LRU pages. */ if (!PageLRU(hpage) && !PageHuge(p)) - goto put_out; + return 0; /* - * do a racy check with elevated page count, to make sure PG_hwpoison - * will only be set for the targeted owner (or on a free page). + * do a racy check to make sure PG_hwpoison will only be set for + * the targeted owner (or on a free page). * memory_failure() will redo the check reliably inside page lock. */ err = hwpoison_filter(hpage); if (err) - goto put_out; + return 0; inject: pr_info("Injecting memory failure at pfn %#lx\n", pfn); - return memory_failure(pfn, MF_COUNT_INCREASED); -put_out: - put_hwpoison_page(p); - return 0; + return memory_failure(pfn, 0); } static int hwpoison_unpoison(void *data, u64 val) _
