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>
This commit is contained in:
Richard Cochran
2011-02-01 13:52:26 +00:00
committed by Thomas Gleixner
parent 65f5d80bdf
commit f1f1d5ebd1
4 changed files with 57 additions and 0 deletions

View File

@@ -675,6 +675,29 @@ long compat_sys_clock_gettime(clockid_t which_clock,
return err;
}
long compat_sys_clock_adjtime(clockid_t which_clock,
struct compat_timex __user *utp)
{
struct timex txc;
mm_segment_t oldfs;
int err, ret;
err = compat_get_timex(&txc, utp);
if (err)
return err;
oldfs = get_fs();
set_fs(KERNEL_DS);
ret = sys_clock_adjtime(which_clock, (struct timex __user *) &txc);
set_fs(oldfs);
err = compat_put_timex(utp, &txc);
if (err)
return err;
return ret;
}
long compat_sys_clock_getres(clockid_t which_clock,
struct compat_timespec __user *tp)
{