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ntp: Split out timex validation from do_adjtimex 

Split out the timex validation done in do_adjtimex into a separate
function. This will help simplify logic in following patches.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
John Stultz 2013-03-22 11:59:04 -07:00
parent 0ed2aef9b3
commit ad460967a2
1 changed files with 28 additions and 13 deletions
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41
kernel/time/ntp.c
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@ -622,17 +622,13 @@ static inline void process_adjtimex_modes(struct timex *txc,
ntp_update_frequency();
}
/*
* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
int do_adjtimex(struct timex *txc)
{
struct timespec ts;
u32 time_tai, orig_tai;
int result;
/* Validate the data before disabling interrupts */
/**
* ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex
*/
int ntp_validate_timex(struct timex *txc)
{
if (txc->modes & ADJ_ADJTIME) {
/* singleshot must not be used with any other mode bits */
if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
@ -644,7 +640,6 @@ int do_adjtimex(struct timex *txc)
/* In order to modify anything, you gotta be super-user! */
if (txc->modes && !capable(CAP_SYS_TIME))
return -EPERM;
/*
* if the quartz is off by more than 10% then
* something is VERY wrong!
@ -655,12 +650,32 @@ int do_adjtimex(struct timex *txc)
return -EINVAL;
}
if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
return -EPERM;
return 0;
}
/*
* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
int do_adjtimex(struct timex *txc)
{
struct timespec ts;
u32 time_tai, orig_tai;
int result;
/* Validate the data before disabling interrupts */
result = ntp_validate_timex(txc);
if (result)
return result;
if (txc->modes & ADJ_SETOFFSET) {
struct timespec delta;
delta.tv_sec = txc->time.tv_sec;
delta.tv_nsec = txc->time.tv_usec;
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (!(txc->modes & ADJ_NANO))
delta.tv_nsec *= 1000;
result = timekeeping_inject_offset(&delta);