[ 34/94] um: Fix __swp_type()

[Greg KH]

3.3-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Richard Weinberger <richard@xxxxxx>

commit 2b76ebaa728f8a3967c52aa189261c72fe56a6f1 upstream.

The current __swp_type() function uses a too small bitshift.
Using more than one swap files causes bad pages because
the type bits clash with other page flags.

Analyzed-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Richard Weinberger <richard@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/um/include/asm/pgtable.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -346,11 +346,11 @@ extern pte_t *virt_to_pte(struct mm_stru
 #define update_mmu_cache(vma,address,ptep) do ; while (0)
 
 /* Encode and de-code a swap entry */
-#define __swp_type(x)			(((x).val >> 4) & 0x3f)
+#define __swp_type(x)			(((x).val >> 5) & 0x1f)
 #define __swp_offset(x)			((x).val >> 11)
 
 #define __swp_entry(type, offset) \
-	((swp_entry_t) { ((type) << 4) | ((offset) << 11) })
+	((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
 #define __pte_to_swp_entry(pte) \
 	((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/