Add support for timeconting in userland.

This diff exposes parts of clock_gettime(2) and gettimeofday(2) to
userland via libc eliberating processes from the need for a context
switch everytime they want to count the passage of time.

If a timecounter clock can be exposed to userland than it needs to set
its tc_user member to a non-zero value. Tested with one or multiple
counters per architecture.

The timing data is shared through a pointer found in the new ELF
auxiliary vector AUX_openbsd_timekeep containing timehands information
that is frequently updated by the kernel.

Timing differences between the last kernel update and the current time
are adjusted in userland by the tc_get_timecount() function inside the
MD usertc.c file.

This permits a much more responsive environment, quite visible in
browsers, office programs and gaming (apparently one is are able to fly
in Minecraft now).

Tested by robert@, sthen@, naddy@, kmos@, phessler@, and many others!

OK from at least kettenis@, cheloha@, naddy@, sthen@

1 files changed, 3 insertions, 3 deletions

diff --git a/lib/libc/rpc/auth_unix.c b/lib/libc/rpc/auth_unix.c
index 402d98cede4..de2c14d246e 100644
--- a/lib/libc/rpc/auth_unix.c
+++ b/lib/libc/rpc/auth_unix.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: auth_unix.c,v 1.27 2019/06/28 13:32:42 deraadt Exp $ */
+/*	$OpenBSD: auth_unix.c,v 1.28 2020/07/06 13:33:06 pirofti Exp $ */
 
 /*
  * Copyright (c) 2010, Oracle America, Inc.
@@ -121,7 +121,7 @@ authunix_create(char *machname, int uid, int gid, int len, int *aup_gids)
 	/*
 	 * fill in param struct from the given params
 	 */
-	(void)gettimeofday(&now,  NULL);
+	(void)WRAP(gettimeofday)(&now,  NULL);
 	aup.aup_time = now.tv_sec;
 	aup.aup_machname = machname;
 	aup.aup_uid = uid;
@@ -274,7 +274,7 @@ authunix_refresh(AUTH *auth)
 		goto done;
 
 	/* update the time and serialize in place */
-	(void)gettimeofday(&now, NULL);
+	(void)WRAP(gettimeofday)(&now, NULL);
 	aup.aup_time = now.tv_sec;
 	xdrs.x_op = XDR_ENCODE;
 	XDR_SETPOS(&xdrs, 0);