Merge tag 'v5.12-rc8' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 20 insertions, 5 deletions

diff --git a/mm/internal.h b/mm/internal.h
index 9902648f2206..cb3c5e0a7799 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -97,6 +97,26 @@ static inline void set_page_refcounted(struct page *page)
 	set_page_count(page, 1);
 }
 
+/*
+ * When kernel touch the user page, the user page may be have been marked
+ * poison but still mapped in user space, if without this page, the kernel
+ * can guarantee the data integrity and operation success, the kernel is
+ * better to check the posion status and avoid touching it, be good not to
+ * panic, coredump for process fatal signal is a sample case matching this
+ * scenario. Or if kernel can't guarantee the data integrity, it's better
+ * not to call this function, let kernel touch the poison page and get to
+ * panic.
+ */
+static inline bool is_page_poisoned(struct page *page)
+{
+	if (PageHWPoison(page))
+		return true;
+	else if (PageHuge(page) && PageHWPoison(compound_head(page)))
+		return true;
+
+	return false;
+}
+
 extern unsigned long highest_memmap_pfn;
 
 /*
@@ -296,11 +316,6 @@ static inline unsigned int buddy_order(struct page *page)
  */
 #define buddy_order_unsafe(page)	READ_ONCE(page_private(page))
 
-static inline bool is_cow_mapping(vm_flags_t flags)
-{
-	return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
-}
-
 /*
  * These three helpers classifies VMAs for virtual memory accounting.
  */