1 files changed, 33 insertions, 0 deletions

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 620b0b46159..6b44e52caca 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -45,6 +45,7 @@
 #include <linux/page-isolation.h>
 #include <linux/suspend.h>
 #include <linux/slab.h>
+#include <linux/swapops.h>
 #include "internal.h"
 
 int sysctl_memory_failure_early_kill __read_mostly = 0;
@@ -1296,3 +1297,35 @@ done:
         /* keep elevated page count for bad page */
         return ret;
 }
+
+/*
+ * The caller must hold current->mm->mmap_sem in read mode.
+ */
+int is_hwpoison_address(unsigned long addr)
+{
+        pgd_t *pgdp;
+        pud_t pud, *pudp;
+        pmd_t pmd, *pmdp;
+        pte_t pte, *ptep;
+        swp_entry_t entry;
+
+        pgdp = pgd_offset(current->mm, addr);
+        if (!pgd_present(*pgdp))
+                return 0;
+        pudp = pud_offset(pgdp, addr);
+        pud = *pudp;
+        if (!pud_present(pud) || pud_large(pud))
+                return 0;
+        pmdp = pmd_offset(pudp, addr);
+        pmd = *pmdp;
+        if (!pmd_present(pmd) || pmd_large(pmd))
+                return 0;
+        ptep = pte_offset_map(pmdp, addr);
+        pte = *ptep;
+        pte_unmap(ptep);
+        if (!is_swap_pte(pte))
+                return 0;
+        entry = pte_to_swp_entry(pte);
+        return is_hwpoison_entry(entry);
+}
+EXPORT_SYMBOL_GPL(is_hwpoison_address);