Merge branch 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux...

[pandora-kernel.git] / mm / memory-failure.c

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index d0b420a..9c26eec 100644 (file)
--- 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 <linux/hugetlb.h>
 #include "internal.h"
 
@@ -1356,3 +1357,35 @@ 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);