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>
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 59e2749..457d2ba 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -622,17 +622,13 @@
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 @@
/* 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 @@
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);