[PATCH 3.16 076/157] powerpc/vdso32: fix CLOCK_MONOTONIC on PPC64

[Ben Hutchings]

3.16.72-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Christophe Leroy <christophe.leroy@xxxxxx>

commit dd9a994fc68d196a052b73747e3366c57d14a09e upstream.

Commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC
inconsistencies across Y2038") changed the type of wtom_clock_sec
to s64 on PPC64. Therefore, VDSO32 needs to read it with a 4 bytes
shift in order to retrieve the lower part of it.

Fixes: b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038")
Reported-by: Christian Zigotzky <chzigotzky@xxxxxxxxxxx>
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/powerpc/kernel/vdso32/gettimeofday.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -98,7 +98,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
 	 * can be used, r7 contains NSEC_PER_SEC.
 	 */
 
-	lwz	r5,WTOM_CLOCK_SEC(r9)
+	lwz	r5,(WTOM_CLOCK_SEC+LOPART)(r9)
 	lwz	r6,WTOM_CLOCK_NSEC(r9)
 
 	/* We now have our offset in r5,r6. We create a fake dependency