[PATCH 5.10 070/126] s390/vdso: copy tod_steering_delta value to vdso_data page

Greg Kroah-Hartman
2021-04-05T09:12:01Z

From: Heiko Carstens <hca@linux.ibm.com>

commit 72bbc226ed2ef0a46c165a482861fff00dd6d4e1 upstream.

When converting the vdso assembler code to C it was forgotten to
actually copy the tod_steering_delta value to vdso_data page.

Which in turn means that tod clock steering will not work correctly.

Fix this by simply copying the value whenever it is updated.

Fixes: 4bff8cb54502 ("s390: convert to GENERIC_VDSO")
Cc: <stable@vger.kernel.org> # 5.10
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/s390/kernel/time.c | 1 +
1 file changed, 1 insertion(+)

--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -398,6 +398,7 @@ static void clock_sync_global(unsigned l
tod_steering_delta);
tod_steering_end = now + (abs(tod_steering_delta) << 15);
vdso_data->arch_data.tod_steering_end = tod_steering_end;
+ vdso_data->arch_data.tod_steering_delta = tod_steering_delta;

/* Update LPAR offset. */
if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)