nice(): Correct return value and [EPERM] error.

PR:		189821
Obtained from:	NetBSD
Relnotes:	yes

3 files changed, 32 insertions, 33 deletions

diff --git a/contrib/netbsd-tests/lib/libc/gen/t_nice.c b/contrib/netbsd-tests/lib/libc/gen/t_nice.c
index 10b8df7..f4a62e9 100644
--- a/contrib/netbsd-tests/lib/libc/gen/t_nice.c
+++ b/contrib/netbsd-tests/lib/libc/gen/t_nice.c
@@ -72,11 +72,6 @@ ATF_TC_BODY(nice_err, tc)
 {
 	int i;
 
-#ifdef __FreeBSD__
-	atf_tc_expect_fail("nice(incr) with incr < 0 fails with unprivileged "
-	   "users and sets errno == EPERM; see PR # 189821 for more details");
-#endif
-
 	/*
 	 * The call should fail with EPERM if the
 	 * supplied parameter is negative and the
@@ -98,11 +93,7 @@ ATF_TC_HEAD(nice_priority, tc)
 
 ATF_TC_BODY(nice_priority, tc)
 {
-#ifdef __FreeBSD__
-	int i, pri, pri2, nic;
-#else
 	int i, pri, nic;
-#endif
 	pid_t pid;
 	int sta;
 
@@ -115,10 +106,8 @@ ATF_TC_BODY(nice_priority, tc)
 		pri = getpriority(PRIO_PROCESS, 0);
 		ATF_REQUIRE(errno == 0);
 
-#ifdef __NetBSD__
 		if (nic != pri)
 			atf_tc_fail("nice(3) and getpriority(2) conflict");
-#endif
 
 		/*
 		 * Also verify that the nice(3) values
@@ -130,18 +119,10 @@ ATF_TC_BODY(nice_priority, tc)
 		if (pid == 0) {
 
 			errno = 0;
-#ifdef __FreeBSD__
 			pri = getpriority(PRIO_PROCESS, 0);
-#else
-			pri2 = getpriority(PRIO_PROCESS, 0);
-#endif
 			ATF_REQUIRE(errno == 0);
 
-#ifdef __FreeBSD__
-			if (pri != pri2)
-#else
 			if (nic != pri)
-#endif
 				_exit(EXIT_FAILURE);
 
 			_exit(EXIT_SUCCESS);
@@ -180,11 +161,7 @@ ATF_TC_HEAD(nice_thread, tc)
 ATF_TC_BODY(nice_thread, tc)
 {
 	pthread_t tid[5];
-#ifdef __FreeBSD__
-	int pri, rv, val;
-#else
 	int rv, val;
-#endif
 	size_t i;
 
 	/*
@@ -196,12 +173,7 @@ ATF_TC_BODY(nice_thread, tc)
 		val = nice(i);
 		ATF_REQUIRE(val != -1);
 
-#ifdef __FreeBSD__
-		pri = getpriority(PRIO_PROCESS, 0);
-		rv = pthread_create(&tid[i], NULL, threadfunc, &pri);
-#else
 		rv = pthread_create(&tid[i], NULL, threadfunc, &val);
-#endif
 		ATF_REQUIRE(rv == 0);
 
 		rv = pthread_join(tid[i], NULL);
diff --git a/lib/libc/gen/nice.3 b/lib/libc/gen/nice.3
index 9c39b78..3bad5f7 100644
--- a/lib/libc/gen/nice.3
+++ b/lib/libc/gen/nice.3
@@ -28,7 +28,7 @@
 .\"     @(#)nice.3	8.1 (Berkeley) 6/4/93
 .\" $FreeBSD$
 .\"
-.Dd June 4, 1993
+.Dd February 22, 2015
 .Dt NICE 3
 .Os
 .Sh NAME
@@ -57,11 +57,34 @@ Only the super-user may lower priorities.
 .Pp
 Children inherit the priority of their parent processes via
 .Xr fork 2 .
+.Sh RETURN VALUES
+Upon successful completion,
+.Fn nice
+returns the new nice value minus
+.Dv NZERO .
+Otherwise, \-1 is returned, the process' nice value is not changed, and
+.Va errno
+is set to indicate the error.
+.Sh ERRORS
+The
+.Fn nice
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EPERM
+The
+.Fa incr
+argument is negative and the caller does not have appropriate privileges.
+.El
 .Sh SEE ALSO
 .Xr nice 1 ,
 .Xr fork 2 ,
 .Xr setpriority 2 ,
 .Xr renice 8
+.Sh STANDARDS
+The
+.Fn nice
+function conforms to
+.St -xpg4.2 .
 .Sh HISTORY
 A
 .Fn nice
diff --git a/lib/libc/gen/nice.c b/lib/libc/gen/nice.c
index e8375e8..58cde98 100644
--- a/lib/libc/gen/nice.c
+++ b/lib/libc/gen/nice.c
@@ -43,14 +43,18 @@ __FBSDID("$FreeBSD$");
  * Backwards compatible nice.
  */
 int
-nice(incr)
-	int incr;
+nice(int incr)
 {
 	int prio;
 
 	errno = 0;
 	prio = getpriority(PRIO_PROCESS, 0);
 	if (prio == -1 && errno)
-		return (-1);
-	return (setpriority(PRIO_PROCESS, 0, prio + incr));
+		return -1;
+	if (setpriority(PRIO_PROCESS, 0, prio + incr) == -1) {
+		if (errno == EACCES)
+			errno = EPERM;
+		return -1;
+	}
+	return getpriority(PRIO_PROCESS, 0);
 }