[S390] vdso: use ntp adjusted clock multiplier

Commit "timekeeping: Fix clock_gettime vsyscall time warp" (0696b711e)
introduced the new parameter "mult" to update_vsyscall(). This parameter
contains the internal NTP adjusted clock multiplier.

The s390x vdso did not use this adjusted multiplier.  Instead, it used
the constant clock multiplier for gettimeofday() and clock_gettime()
variants.  This may result in observable time warps as explained in
commit 0696b711e.

Make the NTP adjusted clock multiplier available to the s390x vdso
implementation and use it for time calculations.

Cc: <stable@kernel.org>
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 9 insertions, 9 deletions

diff --git a/arch/s390/kernel/vdso32/clock_gettime.S b/arch/s390/kernel/vdso32/clock_gettime.S
index 4a98909a8310..969643954273 100644
--- a/arch/s390/kernel/vdso32/clock_gettime.S
+++ b/arch/s390/kernel/vdso32/clock_gettime.S
@@ -38,13 +38,13 @@ __kernel_clock_gettime:
         sl      %r1,__VDSO_XTIME_STAMP+4(%r5)
         brc     3,2f
         ahi     %r0,-1
-2:      mhi     %r0,1000                        /* cyc2ns(clock,cycle_delta) */
+2:      ms      %r0,__VDSO_NTP_MULT(%r5)        /* cyc2ns(clock,cycle_delta) */
         lr      %r2,%r0
-        lhi     %r0,1000
+        l       %r0,__VDSO_NTP_MULT(%r5)
         ltr     %r1,%r1
         mr      %r0,%r0
         jnm     3f
-        ahi     %r0,1000
+        a       %r0,__VDSO_NTP_MULT(%r5)
 3:      alr     %r0,%r2
         srdl    %r0,12
         al      %r0,__VDSO_XTIME_NSEC(%r5)      /*  + xtime */
@@ -86,13 +86,13 @@ __kernel_clock_gettime:
         sl      %r1,__VDSO_XTIME_STAMP+4(%r5)
         brc     3,12f
         ahi     %r0,-1
-12:     mhi     %r0,1000                        /* cyc2ns(clock,cycle_delta) */
+12:     ms      %r0,__VDSO_NTP_MULT(%r5)        /* cyc2ns(clock,cycle_delta) */
         lr      %r2,%r0
-        lhi     %r0,1000
+        l       %r0,__VDSO_NTP_MULT(%r5)
         ltr     %r1,%r1
         mr      %r0,%r0
         jnm     13f
-        ahi     %r0,1000
+        a       %r0,__VDSO_NTP_MULT(%r5)
 13:     alr     %r0,%r2
         srdl    %r0,12
         al      %r0,__VDSO_XTIME_NSEC(%r5)      /*  + xtime */
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S
index ad8acfc949fb..2d3633175e3b 100644
--- a/arch/s390/kernel/vdso32/gettimeofday.S
+++ b/arch/s390/kernel/vdso32/gettimeofday.S
@@ -35,13 +35,13 @@ __kernel_gettimeofday:
         sl      %r1,__VDSO_XTIME_STAMP+4(%r5)
         brc     3,3f
         ahi     %r0,-1
-3:      mhi     %r0,1000                        /* cyc2ns(clock,cycle_delta) */
+3:      ms      %r0,__VDSO_NTP_MULT(%r5)        /* cyc2ns(clock,cycle_delta) */
         st      %r0,24(%r15)
-        lhi     %r0,1000
+        l       %r0,__VDSO_NTP_MULT(%r5)
         ltr     %r1,%r1
         mr      %r0,%r0
         jnm     4f
-        ahi     %r0,1000
+        a       %r0,__VDSO_NTP_MULT(%r5)
 4:      al      %r0,24(%r15)
         srdl    %r0,12
         al      %r0,__VDSO_XTIME_NSEC(%r5)      /*  + xtime */