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| author | Richard Cochran <richardcochran@gmail.com> | 2011-02-01 13:52:26 +0000 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2011-02-02 15:28:19 +0100 |
| commit | f1f1d5ebd10ffa4242bce7a90a56a222d6b7bc77 (patch) | |
| tree | ca04ea979512e0037c52bca855dbf050b1b08360 /kernel/posix-timers.c | |
| parent | 65f5d80bdf83ec0d7f3887db10153bf3f36ed73c (diff) | |
| download | linux-f1f1d5ebd10ffa4242bce7a90a56a222d6b7bc77.tar.bz2 | |
posix-timers: Introduce a syscall for clock tuning.
A new syscall is introduced that allows tuning of a POSIX clock. The
new call, clock_adjtime, takes two parameters, the clock ID and a
pointer to a struct timex. Any ADJTIMEX(2) operation may be requested
via this system call, but various POSIX clocks may or may not support
tuning.
[ tglx: Adapted to the posix-timer cleanup series. Avoid copy_to_user
in the error case ]
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134419.869804645@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/posix-timers.c')
| -rw-r--r-- | kernel/posix-timers.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c index a3fdfd4be0ec..5a5a4f1c0971 100644 --- a/kernel/posix-timers.c +++ b/kernel/posix-timers.c @@ -170,6 +170,12 @@ static int posix_clock_realtime_set(const clockid_t which_clock, return do_sys_settimeofday(tp, NULL); } +static int posix_clock_realtime_adj(const clockid_t which_clock, + struct timex *t) +{ + return do_adjtimex(t); +} + /* * Get monotonic time for posix timers */ @@ -216,6 +222,7 @@ static __init int init_posix_timers(void) .clock_getres = hrtimer_get_res, .clock_get = posix_clock_realtime_get, .clock_set = posix_clock_realtime_set, + .clock_adj = posix_clock_realtime_adj, .nsleep = common_nsleep, .nsleep_restart = hrtimer_nanosleep_restart, .timer_create = common_timer_create, @@ -948,6 +955,29 @@ SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock, return error; } +SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock, + struct timex __user *, utx) +{ + struct k_clock *kc = clockid_to_kclock(which_clock); + struct timex ktx; + int err; + + if (!kc) + return -EINVAL; + if (!kc->clock_adj) + return -EOPNOTSUPP; + + if (copy_from_user(&ktx, utx, sizeof(ktx))) + return -EFAULT; + + err = kc->clock_adj(which_clock, &ktx); + + if (!err && copy_to_user(utx, &ktx, sizeof(ktx))) + return -EFAULT; + + return err; +} + SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp) { |