ntp: Provide compability defines (You say MOD_NANO, I say ADJ_NANO)

MOD_NANO, ADJ_NANO, MOD_NANO, ADJ_NANO!
Lets call the whole thing off!
But oh! If we call the whole thing off,
Then we must part.
And oh! If we ever part,
Then that might break my heart^H^H^H^Hclock!
So, if you like MOD_NANO and I like ADJ_NANO,
I'll include MOD_NANO and give up ADJ_NANO (not really!).
For we know we need each other,
So we better call the calling off off.
Let's call the whole thing off!

The tumultuous NTP and Linux relationship has hit another snag: Ends
up NTPd still uses the "xntp 3.4 compatability names" and when the
STA_NANO value was added (along with ADJ_NANO), NTPd expected MOD_NANO
to be added and has apparently hit some build errors.

Report to ntp hackers:
https://lists.ntp.org/pipermail/hackers/2009-August/004455.html

Related Bugs:
https://support.ntp.org/bugs/show_bug.cgi?id=1219
https://bugzilla.redhat.com/show_bug.cgi?id=505566

So in an effort to make peace, here's a patch to help get things
building again. I also have updated the comment to make sure folks
don't think the MOD_* values are just legacy constants.

Of course, NTPd really uses the glibc-headers, so those will need to
be similarly updated before things are working again (the RH bug above
should probably cover that).

Thanks to Michael Tatarinov and Hal Murray for finding and reporting
the issue!

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: hmurray@megapathdsl.net
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Michael Tatarinov <kukabu@gmail.com>
LKML-Reference: <1251417882.7905.42.camel@localhost.localdomain>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/timex.h b/include/linux/timex.h
index e6967d10d9e5..782ccd45c0d9 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -115,13 +115,16 @@ struct timex {
 #define ADJ_OFFSET_SS_READ      0xa001  /* read-only adjtime */
 #endif
 
-/* xntp 3.4 compatibility names */
+/* NTP userland likes the MOD_ prefix better */
 #define MOD_OFFSET      ADJ_OFFSET
 #define MOD_FREQUENCY   ADJ_FREQUENCY
 #define MOD_MAXERROR    ADJ_MAXERROR
 #define MOD_ESTERROR    ADJ_ESTERROR
 #define MOD_STATUS      ADJ_STATUS
 #define MOD_TIMECONST   ADJ_TIMECONST
+#define MOD_TAI ADJ_TAI
+#define MOD_MICRO       ADJ_MICRO
+#define MOD_NANO        ADJ_NANO
 
 
 /*