OS-6014 native gettimeofday should use comm page

Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Approved by: Jerry Jelinek <jerry.jelinek@joyent.com>

usr/src/cmd/sgs/rtld/common/external.c

@@ -22,7 +22,7 @@
 /*
  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2014 Garrett D'Amore <garrett@damore.org>
- * Copyright 2016 Joyent, Inc.
+ * Copyright (c) 2017, Joyent, Inc.
  */
 
 /*
@@ -723,9 +723,9 @@ isalnum(int c)
 
 #if defined(__i386) || defined(__amd64)
 /*
- * Instead of utilizing the comm page for clock_gettime, rtld uses the raw
- * syscall instead.  Doing so decreases the surface of symbols needed from libc
- * for a modest performance cost.
+ * Instead of utilizing the comm page for clock_gettime and gettimeofday, rtld
+ * uses the raw syscall instead.  Doing so decreases the surface of symbols
+ * needed from libc for a modest performance cost.
  */
 extern int __clock_gettime_sys(clockid_t, struct timespec *);
 
@@ -734,6 +734,22 @@ __clock_gettime(clockid_t clock_id, struct timespec *tp)
 {
 	return (__clock_gettime_sys(clock_id, tp));
 }
+
+int
+gettimeofday(struct timeval *tv, void *tz)
+{
+	if (tv != NULL) {
+		/*
+		 * Perform the same logic as the libc gettimeofday() when it
+		 * lacks comm page support: Make the clock_gettime syscall and
+		 * divide out the tv_usec field as required.
+		 */
+		__clock_gettime_sys(CLOCK_REALTIME, (timespec_t *)tv);
+		tv->tv_usec /= 1000;
+	}
+
+	return (0);
+}
 #endif /* defined(__i386) || defined(__amd64) */
 
 /*

usr/src/lib/libc/amd64/Makefile

@@ -20,7 +20,7 @@
 #
 #
 # Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
-# Copyright 2016 Joyent, Inc.
+# Copyright (c) 2017, Joyent, Inc.
 #
 # Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved.
 # Copyright 2013 Garrett D'Amore <garrett@damore.org>
@@ -1198,6 +1198,7 @@ $(PORTI18N_COND:%=pics/%) := \
 pics/arc4random.o :=	CPPFLAGS += -I$(SRC)/common/crypto/chacha
 
 pics/__clock_gettime.o := CPPFLAGS += $(COMMPAGE_CPPFLAGS)
+pics/gettimeofday.o := CPPFLAGS += $(COMMPAGE_CPPFLAGS)
 
 .KEEP_STATE:
 

usr/src/lib/libc/i386/Makefile.com

@@ -20,7 +20,7 @@
 #
 #
 # Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
-# Copyright 2016 Joyent, Inc.
+# Copyright (c) 2017, Joyent, Inc.
 # Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved.
 # Copyright 2013 Garrett D'Amore <garrett@damore.org>
 #
@@ -1265,6 +1265,7 @@ $(PORTI18N_COND:%=pics/%) := \
 pics/arc4random.o :=	CPPFLAGS += -I$(SRC)/common/crypto/chacha
 
 pics/__clock_gettime.o := CPPFLAGS += $(COMMPAGE_CPPFLAGS)
+pics/gettimeofday.o := CPPFLAGS += $(COMMPAGE_CPPFLAGS)
 
 .KEEP_STATE:
 

usr/src/lib/libc/i386/sys/gettimeofday.c

@@ -0,0 +1,50 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright (c) 2017, Joyent, Inc.
+ */
+
+
+#include "thr_uberdata.h"
+#include <cp_defs.h>
+
+#pragma weak _gettimeofday = gettimeofday
+
+extern int __clock_gettime_sys(clockid_t, timespec_t *);
+
+int
+gettimeofday(struct timeval *tv, void *tz)
+{
+	comm_page_t *cp = (comm_page_t *)__uberdata.ub_comm_page;
+
+	/*
+	 * Perform a NULL check before attempting to store the result directly.
+	 * The old fasttrop logic would perform this same check, but after the
+	 * call into hrestime().
+	 */
+	if (tv == NULL) {
+		return (0);
+	}
+
+	/*
+	 * Since timeval and timespec structs feature the same effective types
+	 * and layout of their members, the conversion can be done in-place.
+	 */
+	if (cp != NULL && __cp_can_gettime(cp) != 0) {
+		__cp_clock_gettime_realtime(cp, (struct timespec *)tv);
+	} else {
+		__clock_gettime_sys(CLOCK_REALTIME, (struct timespec *)tv);
+	}
+	/* Convert from tv_nsec to tv_usec */
+	tv->tv_usec /= 1000;
+	return (0);
+}