From 157a1a27d5921fc94db8c14e0d01363d13de99b5 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Thu, 22 Apr 2010 17:17:06 +0200 Subject: [PATCH] [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: Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/vdso.h | 1 + arch/s390/kernel/asm-offsets.c | 1 + arch/s390/kernel/time.c | 1 + arch/s390/kernel/vdso32/clock_gettime.S | 12 ++++++------ arch/s390/kernel/vdso32/gettimeofday.S | 6 +++--- arch/s390/kernel/vdso64/clock_gettime.S | 4 ++-- arch/s390/kernel/vdso64/gettimeofday.S | 2 +- 7 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h index 4a76d9480cce..533f35751aeb 100644 --- a/arch/s390/include/asm/vdso.h +++ b/arch/s390/include/asm/vdso.h @@ -29,6 +29,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Minutes west of Greenwich 0x30 */ __u32 tz_dsttime; /* Type of dst correction 0x34 */ __u32 ectg_available; + __u32 ntp_mult; /* NTP adjusted multiplier 0x3C */ }; struct vdso_per_cpu_data { diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index 08db736dded0..a09408952ed0 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -61,6 +61,7 @@ int main(void) DEFINE(__VDSO_WTOM_NSEC, offsetof(struct vdso_data, wtom_clock_nsec)); DEFINE(__VDSO_TIMEZONE, offsetof(struct vdso_data, tz_minuteswest)); DEFINE(__VDSO_ECTG_OK, offsetof(struct vdso_data, ectg_available)); + DEFINE(__VDSO_NTP_MULT, offsetof(struct vdso_data, ntp_mult)); DEFINE(__VDSO_ECTG_BASE, offsetof(struct vdso_per_cpu_data, ectg_timer_base)); DEFINE(__VDSO_ECTG_USER, offsetof(struct vdso_per_cpu_data, ectg_user_time)); /* constants used by the vdso */ diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index fba6dec156bf..d906bf19c14a 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -221,6 +221,7 @@ void update_vsyscall(struct timespec *wall_time, struct clocksource *clock, vdso_data->xtime_clock_nsec = wall_time->tv_nsec; vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec; vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec; + vdso_data->ntp_mult = mult; smp_wmb(); ++vdso_data->tb_update_count; } 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 */ diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S index 49106c6e6f88..f40467884a03 100644 --- a/arch/s390/kernel/vdso64/clock_gettime.S +++ b/arch/s390/kernel/vdso64/clock_gettime.S @@ -36,7 +36,7 @@ __kernel_clock_gettime: stck 48(%r15) /* Store TOD clock */ lg %r1,48(%r15) sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ - mghi %r1,1000 + msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */ srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */ lg %r0,__VDSO_XTIME_SEC(%r5) @@ -64,7 +64,7 @@ __kernel_clock_gettime: stck 48(%r15) /* Store TOD clock */ lg %r1,48(%r15) sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ - mghi %r1,1000 + msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */ srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */ lg %r0,__VDSO_XTIME_SEC(%r5) diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S index f873e75634e1..36ee674722ec 100644 --- a/arch/s390/kernel/vdso64/gettimeofday.S +++ b/arch/s390/kernel/vdso64/gettimeofday.S @@ -31,7 +31,7 @@ __kernel_gettimeofday: stck 48(%r15) /* Store TOD clock */ lg %r1,48(%r15) sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ - mghi %r1,1000 + msgf %r1,__VDSO_NTP_MULT(%r5) /* * NTP adjustment */ srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime.tv_nsec */ lg %r0,__VDSO_XTIME_SEC(%r5) /* xtime.tv_sec */ -- 2.20.1