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-rw-r--r--mm/internal.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/mm/internal.h b/mm/internal.h
index 1432feec62df..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;
/*