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| author | Heiko Carstens <hca@linux.ibm.com> | 2021-03-24 20:23:55 +0100 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2021-03-25 21:57:26 +0100 |
| commit | 5b43bd184530af6b868d8273b0a743a138d37ee8 (patch) | |
| tree | f8420c59764e10b88616096c178fd8875d5d2ee9 | |
| parent | b24bacd67ffddd9192c4745500fd6f73dbfe565e (diff) | |
| download | vfs-5b43bd184530af6b868d8273b0a743a138d37ee8.tar.gz | |
s390/vdso: fix initializing and updating of vdso_data
Li Wang reported that clock_gettime(CLOCK_MONOTONIC_RAW, ...) returns
incorrect values when time is provided via vdso instead of system call:
vdso_ts_nsec = 4484351380985507, vdso_ts.tv_sec = 4484351, vdso_ts.tv_nsec = 380985507
sys_ts_nsec = 1446923235377, sys_ts.tv_sec = 1446, sys_ts.tv_nsec = 923235377
Within the s390 specific vdso function __arch_get_hw_counter() reads
tod clock steering values from the arch_data member of the passed in
vdso_data structure.
Problem is that only for the CS_HRES_COARSE vdso_data arch_data is
initialized and gets updated. The CS_RAW specific vdso_data does not
contain any valid tod_clock_steering information, which explains the
different values.
Fix this by initializing and updating all vdso_datas.
Reported-by: Li Wang <liwang@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Fixes: 1ba2d6c0fd4e ("s390/vdso: simplify __arch_get_hw_counter()")
Link: https://lore.kernel.org/linux-s390/YFnxr1ZlMIOIqjfq@osiris
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| -rw-r--r-- | arch/s390/kernel/time.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index e37285a5101be..326cb8f75f58e 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -80,10 +80,12 @@ void __init time_early_init(void) { struct ptff_qto qto; struct ptff_qui qui; + int cs; /* Initialize TOD steering parameters */ tod_steering_end = tod_clock_base.tod; - vdso_data->arch_data.tod_steering_end = tod_steering_end; + for (cs = 0; cs < CS_BASES; cs++) + vdso_data[cs].arch_data.tod_steering_end = tod_steering_end; if (!test_facility(28)) return; @@ -366,6 +368,7 @@ static void clock_sync_global(unsigned long delta) { unsigned long now, adj; struct ptff_qto qto; + int cs; /* Fixup the monotonic sched clock. */ tod_clock_base.eitod += delta; @@ -381,8 +384,10 @@ static void clock_sync_global(unsigned long delta) panic("TOD clock sync offset %li is too large to drift\n", 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; + for (cs = 0; cs < CS_BASES; cs++) { + vdso_data[cs].arch_data.tod_steering_end = tod_steering_end; + vdso_data[cs].arch_data.tod_steering_delta = tod_steering_delta; + } /* Update LPAR offset. */ if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) |