diff --git a/tools/test/stress2/misc/fdatasync.sh b/tools/test/stress2/misc/fdatasync.sh
index f17e2826ad94..9abd31e5bd94 100755
--- a/tools/test/stress2/misc/fdatasync.sh
+++ b/tools/test/stress2/misc/fdatasync.sh
@@ -1,197 +1,197 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2018 Dell EMC Isilon
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # fdatasync(2) fuzz.
 
 # Deadlock seen:
 # https://people.freebsd.org/~pho/stress/log/fdatasync.txt
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 dir=$RUNDIR
 nfiles=500
 [ `df -i $dir | tail -1 | awk '{print $7}'` -lt $nfiles ] && exit 0
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > fdatasync.c
 rm -f /tmp/fdatasync
 mycc -o fdatasync -Wall -Wextra -O2 -g fdatasync.c -lpthread || exit 1
 rm -f fdatasync.c
 
 mkdir -p $dir && chmod 777 $dir
 
 cd $dir
 jot $nfiles | xargs touch
 jot $nfiles | xargs chmod 666
 cd $odir
 
 (cd /tmp; /tmp/fdatasync $dir)
 e=$?
 
 rm -rf $dir/* /tmp/fdatasync
 exit $e
 EOF
 #include <sys/param.h>
 #include <sys/resource.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 #define RUNTIME 180
 #define THREADS 2
 
 static int fd[900];
 static u_int32_t r[N];
 static char *args[2];
 
 static unsigned long
 makearg(void)
 {
 	unsigned long val;
 
 	val = arc4random();
 #if defined(__LP64__)
 	val = (val << 32) | arc4random();
 	val = val & 0x00007fffffffffffUL;
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 	FTS *fts;
 	FTSENT *p;
 	int ftsoptions, i, n;
 
 	ftsoptions = FTS_PHYSICAL;
 
 	for (;;) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = n = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) ==
 				    -1)
 				continue;
 			if (ftruncate(fd[i], 0) != 0)
 				err(1, "ftruncate");
 			i++;
 			i = i % nitems(fd);
 		}
 
 		if (fts_close(fts) == -1)
 			err(1, "fts_close()");
 		sleep(1);
 	}
 	return(0);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	off_t offset;
 	time_t start;
 	int fd2;
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		fd2 = makearg() % nitems(fd) + 3;
 		offset = makearg();
 		if (lseek(fd2, offset - 1, SEEK_SET) != -1) {
 			if (write(fd2, "x", 1) != 1)
 				if (errno != EBADF && errno != ENOSPC &&
 				    errno != E2BIG && errno != ESTALE &&
 				    errno != EFBIG)
 					warn("write");
 		} else
 			if (errno != EBADF)
 				warn("lseek");
 		if (fdatasync(fd2) == -1)
 			if (errno != EBADF)
 				warn("x");
 
 	}
 
 	return (0);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	pthread_t rp, cp[THREADS];
 	int e, i;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s <dir>\n", argv[0]);
 		exit(1);
 	}
 	args[0] = argv[1];
 	args[1] = 0;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 		errc(1, e, "pthread_create");
 	usleep(1000);
 	for (i = 0; i < THREADS; i++)
 		if ((e = pthread_create(&cp[i], NULL, calls, NULL)) != 0)
 			errc(1, e, "pthread_create");
 	for (i = 0; i < THREADS; i++)
 		pthread_join(cp[i], NULL);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/fdatasync2.sh b/tools/test/stress2/misc/fdatasync2.sh
index 6011eba53698..42ade0cedbd3 100755
--- a/tools/test/stress2/misc/fdatasync2.sh
+++ b/tools/test/stress2/misc/fdatasync2.sh
@@ -1,196 +1,196 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2018 Dell EMC Isilon
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # fdatasync(2) fuzz. Variation of fdatasync.sh.
 # https://people.freebsd.org/~pho/stress/log/fdatasync2.txt
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 dir=$RUNDIR
 nfiles=10000
 [ `df -i $dir | tail -1 | awk '{print $7}'` -lt $nfiles ] && exit 0
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > fdatasync2.c
 rm -f /tmp/fdatasync2
 mycc -o fdatasync2 -Wall -Wextra -O2 -g fdatasync2.c -lpthread || exit 1
 rm -f fdatasync2.c
 
 mkdir -p $dir && chmod 777 $dir
 
 cd $dir
 jot $nfiles | xargs touch
 jot $nfiles | xargs chmod 666
 cd $odir
 
 (cd /tmp; /tmp/fdatasync2 $dir)
 e=$?
 
 rm -rf $dir/* /tmp/fdatasync2
 exit $e
 EOF
 #include <sys/param.h>
 #include <sys/resource.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 #define RUNTIME 180
 #define THREADS 6
 
 static int fd[900];
 static u_int32_t r[N];
 static char *args[2];
 
 static unsigned long
 makearg(void)
 {
 	unsigned long val;
 
 	val = arc4random();
 #if defined(__LP64__)
 	val = (val << 32) | arc4random();
 	val = val & 0x00007fffffffffffUL;
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 	FTS *fts;
 	FTSENT *p;
 	int ftsoptions, i, n;
 
 	ftsoptions = FTS_PHYSICAL;
 
 	for (;;) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = n = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) ==
 				    -1)
 				continue;
 			if (ftruncate(fd[i], 0) != 0)
 				err(1, "ftruncate");
 			i++;
 			i = i % nitems(fd);
 		}
 
 		if (fts_close(fts) == -1)
 			err(1, "fts_close()");
 		sleep(1);
 	}
 	return(0);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	off_t offset;
 	time_t start;
 	int fd2;
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		fd2 = makearg() % nitems(fd) + 3;
 		offset = makearg();
 		if (lseek(fd2, offset - 1, SEEK_SET) != -1) {
 			if (write(fd2, "x", 1) != 1)
 				if (errno != EBADF && errno != ENOSPC &&
 				    errno != E2BIG && errno != ESTALE &&
 				    errno != EFBIG)
 					warn("write");
 		} else
 			if (errno != EBADF)
 				warn("lseek");
 		if (fdatasync(fd2) == -1)
 			if (errno != EBADF)
 				warn("x");
 
 	}
 
 	return (0);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	pthread_t rp, cp[THREADS];
 	int e, i, threads;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s <dir>\n", argv[0]);
 		exit(1);
 	}
 	args[0] = argv[1];
 	args[1] = 0;
 	threads = arc4random() % (THREADS -1 ) + 2; /* 2 - THREADS */
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 		errc(1, e, "pthread_create");
 	usleep(1000);
 	for (i = 0; i < threads; i++)
 		if ((e = pthread_create(&cp[i], NULL, calls, NULL)) != 0)
 			errc(1, e, "pthread_create");
 	for (i = 0; i < threads; i++)
 		pthread_join(cp[i], NULL);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/fifo2.sh b/tools/test/stress2/misc/fifo2.sh
index 4a7b986931d9..e84506cbfb01 100755
--- a/tools/test/stress2/misc/fifo2.sh
+++ b/tools/test/stress2/misc/fifo2.sh
@@ -1,204 +1,204 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2013 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Page fault seen
 # http://people.freebsd.org/~pho/stress/log/kostik654.txt
 # Fixed by r259521.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > fifo2.c
 rm -f /tmp/fifo2
 mycc -o fifo2 -Wall -Wextra -O2 -g fifo2.c -lpthread || exit 1
 rm -f fifo2.c
 
 mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint
 mdconfig -l | grep -q md$mdstart &&  mdconfig -d -u $mdstart
 
 mdconfig -a -t swap -s 1g -u $mdstart || exit 1
 newfs $newfs_flags md$mdstart > /dev/null
 mount /dev/md$mdstart $mntpoint
 chmod 777 $mntpoint
 mkfifo $mntpoint/f
 chmod 777 $mntpoint/f
 
 sleeptime=12
 st=`date '+%s'`
 while [ $((`date '+%s'` - st)) -lt $((10 * sleeptime)) ]; do
 	(cd $mntpoint; /tmp/fifo2) &
 	start=`date '+%s'`
 	while [ $((`date '+%s'` - start)) -lt $sleeptime ]; do
 		pgrep -q fifo2 || break
 		sleep .5
 	done
 	while pkill -9 fifo2; do :; done
 	wait
 done
 
 for i in `jot 10`; do
 	mount | grep -q md$mdstart  && \
 		umount $mntpoint > /dev/null 2>&1 &&
 		    mdconfig -d -u $mdstart && break
 	sleep 10
 done
 s=0
 mount | grep -q md$mdstart &&
     { echo "umount $mntpoint failed"; s=1; }
 rm -f /tmp/fifo2
 exit $s
 EOF
 #include <sys/types.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 static int debug; /* Set to 1 for debug output */
 u_int32_t r[N];
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(1);
 }
 
 static unsigned long
 makearg(void)
 {
 	unsigned int i;
 	unsigned long val;
 
 	val = arc4random();
 	i   = arc4random() % 100;
 	if (i < 20)
 		val = val & 0xff;
 	if (i >= 20 && i < 40)
 		val = val & 0xffff;
 	if (i >= 40 && i < 60)
 		val = (unsigned long)(r) | (val & 0xffff);
 #if defined(__LP64__)
 	if (i >= 60) {
 		val = (val << 32) | arc4random();
 		if (i > 80)
 			val = val & 0x00007fffffffffffUL;
 	}
 #endif
 
 	return(val);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	unsigned long arg1, arg2, arg3, arg4, arg5, arg6, arg7;
 	int i;
 
 	for (i = 0;; i++) {
 		arg1 = (unsigned long)(void *)"f";
 		arg2 = makearg();
 		arg3 = makearg();
 		arg4 = makearg();
 		arg5 = makearg();
 		arg6 = makearg();
 		arg7 = makearg();
 
 		if (debug != 0)
 			fprintf(stderr, "%2d : syscall(%3d, %lx, %lx, %lx, %lx, %lx, %lx, %lx)\n",
 			    i, SYS_open, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
 		usleep(100000);
 		alarm(1);
 		syscall(SYS_open, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
 	}
 
 	return (0);
 }
 
 int
 main(void)
 {
 	struct passwd *pw;
 	struct rlimit limit;
 	pthread_t cp[50];
 	time_t start;
 	int e, j;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	limit.rlim_cur = limit.rlim_max = 1000;
 	if (setrlimit(RLIMIT_NPTS, &limit) < 0)
 		err(1, "setrlimit");
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	start = time(NULL);
 	while ((time(NULL) - start) < 120) {
 		if (fork() == 0) {
 			for (j = 0; j < 1; j++)
 				if ((e = pthread_create(&cp[j], NULL, calls, NULL)) != 0)
 					errc(1, e,"pthread_create");
 
 			for (j = 0; j < 1; j++)
 				pthread_join(cp[j], NULL);
 			_exit(0);
 		}
 		wait(NULL);
 	}
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/ftruncate.sh b/tools/test/stress2/misc/ftruncate.sh
index ddec85b6745a..f9aa1869756f 100755
--- a/tools/test/stress2/misc/ftruncate.sh
+++ b/tools/test/stress2/misc/ftruncate.sh
@@ -1,189 +1,189 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2016 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # ftruncate(2) fuzz.
 
 # "panic: softdep_deallocate_dependencies: dangling deps" seen in
 # 10.3-STABLE:
 # https://people.freebsd.org/~pho/stress/log/ftruncate.txt
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 dir=$RUNDIR
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > ftruncate.c
 rm -f /tmp/ftruncate
 mycc -o ftruncate -Wall -Wextra -O2 -g ftruncate.c -lpthread || exit 1
 rm -f ftruncate.c
 
 rm -rf $dir
 mkdir -p $dir
 chmod 777 $dir
 
 cd $dir
 jot 500 | xargs touch
 jot 500 | xargs chmod 666
 cd $odir
 
 (cd /tmp; /tmp/ftruncate $dir)
 e=$?
 
 rm -rf $dir
 
 rm -f /tmp/ftruncate
 exit $e
 EOF
 #include <sys/param.h>
 #include <sys/resource.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 #define RUNTIME 180
 #define THREADS 2
 
 static int fd[900];
 static u_int32_t r[N];
 static char *args[2];
 
 static unsigned long
 makearg(void)
 {
 	unsigned long val;
 
 	val = arc4random();
 #if defined(__LP64__)
 	val = (val << 32) | arc4random();
 	val = val & 0x00007fffffffffffUL;
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 	FTS *fts;
 	FTSENT *p;
 	int ftsoptions, i, n;
 
 	ftsoptions = FTS_PHYSICAL;
 
 	for (;;) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = n = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) == -1)
 				continue;
 			i++;
 			i = i % nitems(fd);
 		}
 
 		if (fts_close(fts) == -1)
 			err(1, "fts_close()");
 		sleep(1);
 	}
 	return(0);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	off_t offset;
 	time_t start;
 	int fd2;
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		fd2 = makearg() % nitems(fd) + 3;
 		offset = makearg();
 		if (ftruncate(fd2, offset) == 0) {
 			if (lseek(fd2, offset - 1, SEEK_SET) != -1)
 				write(fd2, "x", 1);
 		}
 
 	}
 
 	return (0);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	pthread_t rp, cp[THREADS];
 	int e, i;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s <dir>\n", argv[0]);
 		exit(1);
 	}
 	args[0] = argv[1];
 	args[1] = 0;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 		errc(1, e, "pthread_create");
 	usleep(1000);
 	for (i = 0; i < THREADS; i++)
 		if ((e = pthread_create(&cp[i], NULL, calls, NULL)) != 0)
 			errc(1, e, "pthread_create");
 	for (i = 0; i < THREADS; i++)
 		pthread_join(cp[i], NULL);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/ftruncate2.sh b/tools/test/stress2/misc/ftruncate2.sh
index 35db3a4c5f8d..94d9b6ca810f 100755
--- a/tools/test/stress2/misc/ftruncate2.sh
+++ b/tools/test/stress2/misc/ftruncate2.sh
@@ -1,204 +1,204 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2016 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # A fuzz test triggered a failed block allocation unwinding problem.
 
 # "panic: ffs_blkfree_cg: freeing free block" seen:
 # https://people.freebsd.org/~pho/stress/log/kostik923.txt
 # Fixed by r304232.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > ftruncate2.c
 rm -f /tmp/ftruncate2
 mycc -o ftruncate2 -Wall -Wextra -O2 -g ftruncate2.c -lpthread || exit 1
 rm -f ftruncate2.c
 
 echo "Expect: \"/mnt: write failed, filesystem is full\""
 mount | grep $mntpoint | grep -q "on $mntpoint " && umount -f $mntpoint
 mdconfig -l | grep -q md$mdstart &&  mdconfig -d -u $mdstart
 mdconfig -a -t swap -s 1g -u $mdstart || exit 1
 newfs md$mdstart > /dev/null		# Non SU panics
 mount /dev/md$mdstart $mntpoint
 
 dir=$mntpoint
 chmod 777 $dir
 
 cd $dir
 jot 500 | xargs touch
 jot 500 | xargs chmod 666
 cd $odir
 
 (cd /tmp; /tmp/ftruncate2 $dir)
 e=$?
 
 rm -rf $dir/*
 
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 mdconfig -d -u $mdstart
 rm -f /tmp/ftruncate2
 exit $e
 EOF
 #include <sys/param.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 #define RUNTIME 180
 #define THREADS 2
 
 static int fd[900];
 static u_int32_t r[N];
 static char *args[2];
 
 static unsigned long
 makearg(void)
 {
 	unsigned long val;
 
 	val = arc4random();
 #if defined(__LP64__)
 	val = (val << 32) | arc4random();
 	val = val & 0x00007fffffffffffUL;
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 	FTS *fts;
 	FTSENT *p;
 	int ftsoptions, i, n;
 
 	ftsoptions = FTS_PHYSICAL;
 
 	for (;;) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = n = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) == -1)
 				continue;
 			if (ftruncate(fd[i], 0) != 0)
 				err(1, "ftruncate");
 			i++;
 			i = i % nitems(fd);
 		}
 
 		if (fts_close(fts) == -1)
 			err(1, "fts_close()");
 		sleep(1);
 	}
 	return(0);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	off_t offset;
 	time_t start;
 	int fd2;
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		fd2 = makearg() % nitems(fd) + 3;
 		offset = makearg();
 		if (lseek(fd2, offset - 1, SEEK_SET) != -1) {
 			if (write(fd2, "x", 1) != 1)
 				if (errno != EBADF && errno != ENOSPC && errno != E2BIG &&
 				    errno != ESTALE && errno != EFBIG)
 					warn("write");
 		} else
 			if (errno != EBADF)
 				warn("lseek");
 		if (fsync(fd2) == -1)
 			if (errno != EBADF)
 				warn("x");
 	}
 
 	return (0);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	pthread_t rp, cp[THREADS];
 	int e, i;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s <dir>\n", argv[0]);
 		exit(1);
 	}
 	args[0] = argv[1];
 	args[1] = 0;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 		errc(1, e, "pthread_create");
 	usleep(1000);
 	for (i = 0; i < THREADS; i++)
 		if ((e = pthread_create(&cp[i], NULL, calls, NULL)) != 0)
 			errc(1, e, "pthread_create");
 	for (i = 0; i < THREADS; i++)
 		pthread_join(cp[i], NULL);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/kevent7.sh b/tools/test/stress2/misc/kevent7.sh
index 8b58c35551f7..4c7718c6ae5f 100755
--- a/tools/test/stress2/misc/kevent7.sh
+++ b/tools/test/stress2/misc/kevent7.sh
@@ -1,280 +1,280 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2013 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Threaded syscall(2) fuzz test inspired by the iknowthis test suite
 # by Tavis Ormandy <taviso  cmpxchg8b com>
 
 # kevent(2) with random arguments.
 # Spinning threads seen.
 # Fixed in r255877.
 
 # "panic: softclock_call_cc: act 0xfffff801219a0840 0" seen:
 # https://people.freebsd.org/~pho/stress/log/kevent7.txt
 # Fixed by r315289
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 ulimit -t 200
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > kevent7.c
 rm -f /tmp/kevent7
 mycc -o kevent7 -Wall -Wextra -O2 -g kevent7.c -lpthread || exit 1
 rm -f kevent7.c
 
 mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint
 mdconfig -l | grep -q md$mdstart &&  mdconfig -d -u $mdstart
 
 mdconfig -a -t swap -s 2g -u $mdstart || exit 1
 newfs $newfs_flags md$mdstart > /dev/null
 mount /dev/md$mdstart $mntpoint
 chmod 777 $mntpoint
 
 for i in `jot 5`; do
 	(cd $mntpoint; /tmp/kevent7 $* < /dev/null) &
 	sleep 60
 	while pgrep -q kevent7; do
 		pkill -9 kevent7
 		sleep 1
 	done
 done
 
 for i in `jot 5`; do
 	mount | grep -q md$mdstart  && \
 		umount $mntpoint && mdconfig -d -u $mdstart && break
 	sleep 10
 done
 if mount | grep -q md$mdstart; then
 	fstat $mntpoint
 	echo "umount $mntpoint failed"
 	exit 1
 fi
 rm -f /tmp/kevent7
 exit 0
 EOF
 #include <sys/types.h>
 #include <sys/event.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <signal.h>
 #include <sys/socket.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define THREADS 50
 
 int fd[900], fds[2], socketpr[2];
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 static u_int32_t r[N];
 static int syscallno;
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(1);
 }
 
 static unsigned long
 makearg(void)
 {
 	unsigned int i;
 	unsigned long val;
 
 	val = arc4random();
 	i   = arc4random() % 100;
 	if (i < 20)
 		val = val & 0xff;
 	if (i >= 20 && i < 40)
 		val = val & 0xffff;
 	if (i >= 40 && i < 60)
 		val = (unsigned long)(r) | (val & 0xffff);
 #if defined(__LP64__)
 	if (i >= 60) {
 		val = (val << 32) | arc4random();
 		if (i > 80)
 			val = val & 0x00007fffffffffffUL;
 	}
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 
 	FTS		*fts;
 	FTSENT		*p;
 	int		ftsoptions;
 	int i;
 	char		*args[5];
 
 	ftsoptions = FTS_PHYSICAL;
 	args[0] = "/dev";
 	args[1] = "/proc";
 	args[2] = "/usr/compat/linux/proc";
 	args[3] = ".";
 	args[4] = 0;
 
 	for (;;) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) ==
 				    -1)
 					if ((fd[i] = open(p->fts_path,
 					    O_RDONLY)) == -1)
 						continue;
 			i++;
 			i = i % nitems(fd);
 		}
 
 		if (fts_close(fts) == -1)
 			if (errno != ENOTDIR)
 				warn("fts_close()");
 		if (pipe(fds) == -1)
 			err(1, "pipe()");
 		if (socketpair(PF_UNIX, SOCK_SEQPACKET, 0, socketpr) == -1)
 			err(1, "socketpair()");
 		sleep(1);
 		close(socketpr[0]);
 		close(socketpr[1]);
 		close(fds[0]);
 		close(fds[1]);
 	}
 	return(0);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	unsigned long arg1, arg2, arg3, arg4, arg5, arg6, arg7;
 	int i, kq, num;
 
 	if ((kq = kqueue()) < 0)
 		err(1, "kqueue()");
 	for (i = 0; i < 1000; i++) {
 		if (i == 0)
 			usleep(1000);
 		num = syscallno;
 		arg1 = makearg();
 		arg2 = makearg();
 		arg3 = makearg();
 		arg4 = makearg();
 		arg5 = makearg();
 		arg6 = makearg();
 		arg7 = makearg();
 
 #if 0
 		fprintf(stderr, "%2d : syscall(%3d, %lx, %lx, %lx, %lx, %lx,"
 		   " %lx, %lx)\n",
 			i, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
 #endif
 		alarm(1);
 		syscall(num, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
 		num = 0;
 	}
 	close(kq);
 
 	return (0);
 }
 
 int
 main(void)
 {
 	struct passwd *pw;
 	time_t start;
 	pthread_t rp, cp[THREADS];
 	int e, j, n;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	syscallno = SYS_kevent;
 
 	n = 0;
 	start = time(NULL);
 	while (time(NULL) - start < 120) {
 		if (fork() == 0) {
 			if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 				errc(1, e, "pthread_create");
 			usleep(1000);
 			for (j = 0; j < THREADS; j++) {
 				if ((e = pthread_create(&cp[j], NULL, calls,
 				    NULL)) != 0)
 					errc(1, e, "pthread_create");
 			}
 			for (j = 0; j < THREADS; j++)
 				pthread_join(cp[j], NULL);
 			if ((e = pthread_kill(rp, SIGINT)) != 0)
 				errc(1, e, "pthread_kill");
 			_exit(0);
 		}
 		wait(NULL);
 		if (n++ > 5000)
 			break;
 	}
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/killpg.sh b/tools/test/stress2/misc/killpg.sh
index c6af55a3d593..ea99f5e0d0fd 100755
--- a/tools/test/stress2/misc/killpg.sh
+++ b/tools/test/stress2/misc/killpg.sh
@@ -1,155 +1,155 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2013 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Regression test for r241859:
 # Return EPERM if processes were found but they were unable to be signaled.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 here=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $here/$0 > killpg.c
 mycc -o killpg -Wall -Wextra killpg.c || exit 1
 rm -f killpg.c
 
 /tmp/killpg
 
 rm -f /tmp/killpg
 exit 0
 EOF
 #include <sys/types.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 static pid_t gid, pid;
 
 #define LOOPS 100
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(0);
 }
 
 static void
 nlooper(void)
 {
 	int i;
 
 	setproctitle("nlooper");
 	setpgrp(0, getpid());
 	for (i = 0; i < LOOPS; i++) {
 		if ((pid = fork()) == 0) {
 			signal(SIGINFO, hand);
 			if (arc4random() % 100 < 10)
 				usleep(arc4random() % 100);
 			_exit(0);
 		}
 		wait(NULL);
 	}
 	_exit(0);
 }
 
 static void
 looper(void)
 {
 	int i;
 
 	setproctitle("looper");
 	setpgrp(0, getpid());
 	for (i = 0; i < LOOPS; i++) {
 		if ((pid = fork()) == 0) {
 			signal(SIGINFO, hand);
 			if (arc4random() % 100 < 10)
 				usleep(arc4random() % 100);
 			_exit(0);
 		}
 		wait(NULL);
 	}
 	unlink("cont");
 	_exit(0);
 }
 
 static void
 killer(void)
 {
 	struct passwd *pw;
 
 	setproctitle("killer");
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	if ((gid = fork()) == 0)
 		nlooper();	/* nobody looper */
 
 	sleep(1);
 	while (access("cont", R_OK) == 0) {
 		if (killpg(gid, SIGINFO) == -1) {
 			if (errno == EPERM)
 				continue;
 			warn("FAIL killpg");
 		}
 	}
 	_exit(0);
 }
 
 int
 main(void)
 {
 	int fd;
 
 	if ((fd = open("cont", O_RDWR | O_CREAT, 0666)) == -1)
 		err(1, "creat");
 	close(fd);
 	signal(SIGINFO, SIG_IGN);
 
 	if ((gid = fork()) == 0)
 		looper();
 	if (fork() == 0)
 		killer();
 
 	wait(NULL);
 	wait(NULL);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/killpg2.sh b/tools/test/stress2/misc/killpg2.sh
index 5e986f059637..cf186d686dfd 100755
--- a/tools/test/stress2/misc/killpg2.sh
+++ b/tools/test/stress2/misc/killpg2.sh
@@ -1,197 +1,197 @@
 #!/bin/sh
 
 #
 # SPDX-License-Identifier: BSD-2-Clause
 #
 # Copyright (c) 2023 Peter Holm <pho@FreeBSD.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # killpg(2) version of reaper.sh. No problems seen.
 
 . ../default.cfg
 
 prog=$(basename "$0" .sh)
 cat > /tmp/$prog.c <<EOF
 #include <sys/param.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 
 static volatile u_int *share;
 
 #define CONT 0
 #define GID 1
 #define SYNC 2
 #define MAXP 10000
 
 static void
 hand(int i __unused) {
 	_exit(0);
 }
 
 static void
 looper(void)
 {
 	struct sigaction sa;
 	time_t start;
 	struct passwd *pw;
 	pid_t pids[MAXP];
 	int i, parallel;
 
 	setproctitle("looper");
 	sa.sa_handler = SIG_IGN;
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = 0;
 	if (sigaction(SIGUSR1, &sa, NULL) == -1)
 		err(1, "sigaction");
 
 	if ((pw = getpwnam("TUSER")) == NULL)
 		err(1, "no such user: TUSER");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"TUSER\"");
 	endpwent();
 	setpgrp(0, 0);
 	share[GID] = getpgrp();
 	share[SYNC] = 1;
 	start = time(NULL);
 	while (time(NULL) - start < 120) {
 		parallel = arc4random() % MAXP + 1;
 		for (i = 0; i < parallel; i++) {
 			if ((pids[i] = fork()) == 0) {
 				sa.sa_handler = hand;
 				sigemptyset(&sa.sa_mask);
 				sa.sa_flags = 0;
 				if (sigaction(SIGUSR1, &sa, NULL) == -1)
 					err(1, "sigaction");
 				setproctitle("child");
 				for (;;)
 					pause();
 				_exit(0); /* never reached */
 			}
 			if (pids[i] == -1)
 				err(1, "fork()");
 		}
 		for (i = 0; i < parallel; i++) {
 			if (waitpid(pids[i], NULL, 0) != pids[i])
 				err(1, "waitpid(%d) in looper", pids[i]);
 		}
 	}
 	_exit(0);
 }
 
 static void
 killer(void)
 {
 	int e, gid;
 
 	while (share[SYNC] == 0)
 		;
 	gid = share[GID];
 	while (share[CONT] == 1) {
 		usleep(arc4random() % 50000);
 		gid = share[GID];
 		if (gid != 0) {
 			e = 0;
 			while (e == 0) {
 				if (killpg(gid, SIGUSR1) == -1) {
 					e = 1;
 					if (errno != ESRCH)
 						err(1, "pgkill(%d)", gid);
 				}
 				usleep(5000 + arc4random() % 5000);
 			}
 		}
 	}
 	_exit(0);
 }
 
 int
 main(void)
 {
 	size_t len;
 	time_t start;
 	int lpid, kpid, s1, s2;
 
 	len = PAGE_SIZE;
 	if ((share = mmap(NULL, len, PROT_READ | PROT_WRITE,
 	    MAP_ANON | MAP_SHARED, -1, 0)) == MAP_FAILED)
 		err(1, "mmap");
 
 	start = time(NULL);
 	while (time(NULL) - start < 120) {
 		share[CONT] = 1;
 		share[GID] = 0;
 		share[SYNC] = 0;
 		if ((lpid = fork()) == 0)
 			looper();
 		usleep(arc4random() % 100000);
 		if ((kpid = fork()) == 0)
 			killer();
 
 		if (waitpid(lpid, &s1, 0) != lpid)
 			err(1, "waitpid looper");
 		usleep(arc4random() % 1000);
 		share[CONT] = 0;
 		waitpid(kpid, &s2, 0);
 	}
 
 	return (0);
 }
 EOF
 sed -i '' "s#TUSER#$testuser#" /tmp/$prog.c
 cc -o /tmp/$prog -Wall -Wextra -O0 /tmp/$prog.c || exit 1
 rm /tmp/$prog.c
 
 n=1
 start=`date +%s`
 while true; do
 	/tmp/$prog
 	for i in `jot 50`; do
 		pgrep -q $prog || break
 		sleep .5
 	done
 	if pgrep -q $prog; then
 		e=$((`date +%s` - start))
 		echo "Failed in loop #$n after $e seconds."
 		pgrep "$prog|timeout" | xargs ps -jp
 		pkill $prog
 		rm -f /tmp/$prog
 		exit 1
 	fi
 	[ $((`date +%s` - start)) -ge 600 ] && break
 	n=$((n + 1))
 done
 rm /tmp/$prog
 exit 0
diff --git a/tools/test/stress2/misc/killpg3.sh b/tools/test/stress2/misc/killpg3.sh
index 304b3e320f2f..4fcb4fa7a643 100755
--- a/tools/test/stress2/misc/killpg3.sh
+++ b/tools/test/stress2/misc/killpg3.sh
@@ -1,192 +1,192 @@
 #!/bin/sh
 
 #
 # SPDX-License-Identifier: BSD-2-Clause
 #
 # Copyright (c) 2023 Peter Holm <pho@FreeBSD.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # killpg(2) version of reaper.sh. No problems seen.
 
 . ../default.cfg
 
 prog=$(basename "$0" .sh)
 cat > /tmp/$prog.c <<EOF
 #include <sys/param.h>
 #include <sys/mman.h>
 #include <sys/wait.h>
 
 
 #include <err.h>
 #include <errno.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdatomic.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 
 static _Atomic(int) *share;
 
 #define GID 0
 #define PARALLEL 10
 #define RDY 1
 #define MAXP 7000
 
 static void
 hand(int i __unused) {
 	_exit(0);
 }
 
 static void
 innerloop(int parallel)
 {
 	pid_t pids[MAXP];
 	struct sigaction sa;
 	int i;
 
 	usleep(1000);
 	for (i = 0; i < parallel; i++) {
 		if ((pids[i] = fork()) == 0) {
 			sa.sa_handler = hand;
 			sigemptyset(&sa.sa_mask);
 			sa.sa_flags = 0;
 			if (sigaction(SIGUSR1, &sa, NULL) == -1)
 				err(1, "sigaction");
 			atomic_fetch_add(&share[RDY], 1);
 			setproctitle("child");
 			for (;;)
 				pause();
 			_exit(0); /* never reached */
 		}
 		if (pids[i] == -1)
 			err(1, "fork()");
 	}
 	for (i = 0; i < parallel; i++) {
 		if (waitpid(pids[i], NULL, 0) != pids[i])
 			err(1, "waitpid(%d) in looper", pids[i]);
 	}
 	_exit(0);
 }
 
 static void
 looper(void)
 {
 	struct sigaction sa;
 	struct passwd *pw;
 	pid_t pids[MAXP];
 	int i, parallel;
 
 	setproctitle("looper");
 	sa.sa_handler = SIG_IGN;
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = 0;
 	if (sigaction(SIGUSR1, &sa, NULL) == -1)
 		err(1, "sigaction");
 
 	if ((pw = getpwnam("TUSER")) == NULL)
 		err(1, "no such user: TUSER");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"TUSER\"");
 	endpwent();
 	setpgrp(0, 0);
 	share[GID] = getpgrp();
 	parallel = arc4random() % MAXP + 1;
 	parallel = parallel / PARALLEL * PARALLEL;
 	for (i = 0; i < PARALLEL; i++) {
 		if ((pids[i] = fork()) == 0)
 			innerloop(parallel / PARALLEL);
 	}
 	while (atomic_load(&share[RDY]) != parallel)
 		usleep(10000);
 	if (killpg(share[GID], SIGUSR1) == -1)
 		err(1, "pgkill(%d)", share[GID]);
 	for (i = 0; i < 4; i++) {
 		if (waitpid(pids[i], NULL, 0) != pids[i])
 			err(1, "waitpid(%d) in looper", pids[i]);
 	}
 	_exit(0);
 }
 
 int
 main(void)
 {
 	size_t len;
 	time_t start;
 	int lpid, s1;
 
 	len = PAGE_SIZE;
 	if ((share = mmap(NULL, len, PROT_READ | PROT_WRITE,
 	    MAP_ANON | MAP_SHARED, -1, 0)) == MAP_FAILED)
 		err(1, "mmap");
 
 	start = time(NULL);
 	while (time(NULL) - start < 120) {
 		share[GID] = 0;
 		share[RDY] = 0;
 		if ((lpid = fork()) == 0)
 			looper();
 		if (waitpid(lpid, &s1, 0) != lpid)
 			err(1, "waitpid looper");
 	}
 
 	return (0);
 }
 EOF
 sed -i '' "s#TUSER#$testuser#" /tmp/$prog.c
 mycc -o /tmp/$prog -Wall -Wextra -O0 /tmp/$prog.c || exit 1
 rm /tmp/$prog.c
 
 export MAXSWAPPCT=70
 n=1
 start=`date +%s`
 while true; do
 	../testcases/swap/swap -t 2m -i 20 > /dev/null &
 	/tmp/$prog & pid=$!
 	st=`date +%s`
 	while kill -0 $pid > /dev/null 2>&1; do
 		e=$((`date +%s` - st))
 		if [ $e -ge 120 ]; then
 			while pgrep -q swap; do pkill swap; done
 		fi
 		if [ $e -ge 600 ]; then
 			echo "Failed in loop #$n after $e seconds."
 			ps -jU$testuser | head -20
 			kill $pid
 			pkill -U$testuser
 			wait
 			rm -f /tmp/$prog
 			exit 1
 		fi
 	done
 	wait
 	[ $((`date +%s` - start)) -ge 300 ] && break
 	n=$((n + 1))
 done
 rm /tmp/$prog
 exit 0
diff --git a/tools/test/stress2/misc/maxproc.sh b/tools/test/stress2/misc/maxproc.sh
index 0574def8a605..3241e275375e 100755
--- a/tools/test/stress2/misc/maxproc.sh
+++ b/tools/test/stress2/misc/maxproc.sh
@@ -1,167 +1,167 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2014 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 # Test that a non root user can at most have maxproc - 10 processes.
 
 . ../default.cfg
 
 [ `sysctl -n kern.maxproc` -gt 37028 ] && exit 0	# Excessive run time
 here=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $here/$0 > maxproc.c
 mycc -o maxproc -Wall -Wextra maxproc.c -lkvm || exit 1
 rm -f maxproc.c
 cd $here
 
 /tmp/maxproc
 
 rm -f /tmp/maxproc
 exit
 EOF
 #include <sys/wait.h>
 
 #include <err.h>
 #include <fcntl.h>
 #include <kvm.h>
 #include <limits.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 
 enum {
 	NL_NPROCS,
 	NL_MAXPROC,
 	NL_MARKER
 };
 
 static struct {
 	int order;
 	const char *name;
 } namelist[] = {
 	{ NL_NPROCS, "_nprocs" },
 	{ NL_MAXPROC, "_maxproc" },
 	{ NL_MARKER, "" },
 };
 
 #define NNAMES	(sizeof(namelist) / sizeof(*namelist))
 #define MULTIUSERFUZZ 5
 
 static struct nlist nl[NNAMES];
 
 static void
 t2(void)
 {
 	pid_t p;
 
 	for (;;) {
 		if ((p = fork()) == 0) {
 			sleep(2);
 			_exit(0);
 		}
 		if (p == -1)
 			break;
 	}
 }
 
 static void
 t1(int priv)
 {
 	pid_t p;
 	struct passwd *pw;
 
 	if ((p = fork()) == 0) {
 		if ((pw = getpwnam("nobody")) == NULL)
 			err(1, "no such user: nobody");
 
 		if (priv == 0) {
-			if (setgroups(1, &pw->pw_gid) ||
+			if (setgroups(0, NULL) ||
 			    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 			    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 				err(1, "Can't drop privileges to \"nobody\"");
 		}
 		endpwent();
 
 		t2();
 		_exit(0);
 	}
 	waitpid(p, NULL, 0);
 }
 
 int
 getprocs(void)
 {
 	kvm_t *kd;
 	int i, nprocs, maxproc;
 	char buf[_POSIX2_LINE_MAX];
 	char *nlistf, *memf;
 
 	nlistf = memf = NULL;
 	for (i = 0; i < (int)NNAMES; i++)
 		nl[namelist[i].order].n_name = strdup(namelist[i].name);
 
 	if ((kd = kvm_openfiles(nlistf, memf, NULL, O_RDONLY, buf)) == NULL)
 		errx(1, "kvm_openfile(%s, %s): %s", nlistf, memf, buf);
 	if (kvm_nlist(kd, nl) == -1)
 		errx(1, "kvm_nlist: %s", kvm_geterr(kd));
 	if (kvm_read(kd, nl[NL_NPROCS].n_value, &nprocs,
 	    sizeof(nprocs)) != sizeof(nprocs))
 		errx(1, "kvm_read(): %s", kvm_geterr(kd));
 	if (kvm_read(kd, nl[NL_MAXPROC].n_value, &maxproc,
 	    sizeof(maxproc)) != sizeof(maxproc))
 		errx(1, "kvm_read(): %s", kvm_geterr(kd));
 	kvm_close(kd);
 
 	return (maxproc - nprocs - 1);
 }
 
 int
 main(void)
 {
 	int i, n;
 
 	alarm(1200);
 	n = getprocs();
 	for (i = 0; i < n / 10 * 8; i++) {
 		if (fork() == 0) {
 			sleep(2);
 			_exit(0);
 		}
 	}
 
 	t1(0);
 
 	n = getprocs();
 	if (n < 10 - MULTIUSERFUZZ)
 		errx(1, "FAIL: nprocs = %d\n", n);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/mlockall3.sh b/tools/test/stress2/misc/mlockall3.sh
index 0ff1e24eaa7f..aa53e75166a5 100755
--- a/tools/test/stress2/misc/mlockall3.sh
+++ b/tools/test/stress2/misc/mlockall3.sh
@@ -1,167 +1,167 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2013 Peter Holm <pho@FreeBSD.org>
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # mlockall(2) test scenario.
 # "panic: vm_page_unwire: page xxx's wire count is zero" seen.
 # http://people.freebsd.org/~pho/stress/log/mlockall.txt
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 dir=/tmp
 odir=`pwd`
 cd $dir
 sed '1,/^EOF/d' < $odir/$0 > $dir/mlockall3.c
 mycc -o mlockall3 -Wall -Wextra mlockall3.c -lpthread || exit 1
 rm -f mlockall3.c
 cd $odir
 
 /tmp/mlockall3
 
 killall mlockall3 > /dev/null 2>&1
 rm -f /tmp/mlockall3
 exit
 
 EOF
 #include <sys/types.h>
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <signal.h>
 #include <sys/mman.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 u_int32_t r[N];
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(1);
 }
 
 unsigned long
 makearg(void)
 {
 	unsigned int i;
 	unsigned long val;
 
 	val = arc4random();
 	i   = arc4random() % 100;
 	if (i < 20)
 		val = val & 0xff;
 	if (i >= 20 && i < 40)
 		val = val & 0xffff;
 	if (i >= 40 && i < 60)
 		val = (unsigned long)(r) | (val & 0xffff);
 #if defined(__LP64__)
 	if (i >= 60) {
 		val = (val << 32) | arc4random();
 		if (i > 80)
 			val = val & 0x00007fffffffffffUL;
 	}
 #endif
 
 	return(val);
 }
 
 void *
 calls(void *arg __unused)
 {
 	int i;
 	unsigned long arg1, arg2, arg3;
 
 	usleep(1000);
 	for (i = 0; i < 500; i++) {
 		arg1 = makearg();
 		arg2 = makearg();
 		arg3 = makearg();
 
 		alarm(1);
 		syscall(SYS_mlockall, arg1, arg2, arg3);
 	}
 
 	return (0);
 }
 
 int
 main(void)
 {
 	struct passwd *pw;
 	pid_t pid;
 	pthread_t cp[50];
 	int e, i, j;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	alarm(180);
 	for (i = 0; i < 8000; i++) {
 		if ((pid = fork()) == 0) {
 			for (j = 0; j < N; j++)
 				r[j] = arc4random();
 			for (j = 0; j < 50; j++)
 				if ((e = pthread_create(&cp[j], NULL, calls, NULL)) != 0)
 					errc(1, e, "pthread_create");
 
 			for (j = 0; j < 50; j++)
 				pthread_join(cp[j], NULL);
 			_exit(0);
 		}
 		if (pid == -1)
 			err(1, "fork()");
 		wait(NULL);
 	}
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/mlockall7.sh b/tools/test/stress2/misc/mlockall7.sh
index 987e312f19e7..5a927043cb56 100755
--- a/tools/test/stress2/misc/mlockall7.sh
+++ b/tools/test/stress2/misc/mlockall7.sh
@@ -1,262 +1,262 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2014 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Variation of mmap18.sh.
 # "panic: vm_page_unwire: page 0xfffff81038d721f0's wire count is zero" seen:
 # https://people.freebsd.org/~pho/stress/log/mlockall7.txt
 # Fixed by r328880
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 here=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $here/$0 > mlockall7.c
 mycc -o mlockall7 -Wall -Wextra -O2 mlockall7.c -lpthread || exit 1
 rm -f mlockall7.c
 
 /tmp/mlockall7 `[ $# -eq 0 ] && echo 1 || echo $1` || s=1
 
 sleep 2
 rm -f /tmp/mlockall7 /tmp/mlockall7.core
 exit $s
 EOF
 #include <sys/types.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/sysctl.h>
 #include <sys/time.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <fcntl.h>
 #include <pwd.h>
 #include <pthread.h>
 #include <pthread_np.h>
 #include <sched.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
 
 #define N 4096
 #define PARALLEL 50
 #define RUNTIME 180
 
 static u_int32_t r[N];
 static void *p;
 
 static unsigned long
 makearg(void)
 {
 	unsigned long val;
 	unsigned int i;
 
 	val = arc4random();
 	i   = arc4random() % 100;
 	if (i < 20)
 		val = val & 0xff;
 	if (i >= 20 && i < 40)
 		val = val & 0xffff;
 	if (i >= 40 && i < 60)
 		val = (unsigned long)(r) | (val & 0xffff);
 #if defined(__LP64__)
 	if (i >= 60) {
 		val = (val << 32) | arc4random();
 		if (i > 80)
 			val = val & 0x00007fffffffffffUL;
 	}
 #endif
 
 	return (val);
 }
 
 static void *
 tmmap(void *arg __unused)
 {
 	size_t len;
 	time_t start;
 
 	pthread_set_name_np(pthread_self(), __func__);
 	len = 128LL * 1024 * 1024;
 
 	start = time(NULL);
 	while (time(NULL) - start < 60) {
 		if ((p = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_ANON,
 		    -1, 0)) != MAP_FAILED) {
 			usleep(100);
 			munmap(p, len);
 		}
 	}
 
 	return (NULL);
 }
 
 static void *
 tmlockall(void *arg __unused)
 {
 	time_t start;
 	int flags;
 
 	pthread_set_name_np(pthread_self(), __func__);
 	start = time(NULL);
 	while (time(NULL) - start < 60) {
 		flags = makearg() & 0xff;
 		mlockall(flags);
 		usleep(100);
 		munlockall();
 		usleep(1000);
 	}
 
 	return (NULL);
 }
 
 static void
 test(void)
 {
 	pthread_t tid[2];
 	time_t start;
 	int i, rc;
 
 	if ((rc = pthread_create(&tid[0], NULL, tmmap, NULL)) != 0)
 		errc(1, rc, "tmmap()");
 	if ((rc = pthread_create(&tid[1], NULL, tmlockall, NULL)) != 0)
 		errc(1, rc, "tmlock()");
 
 	start = time(NULL);
 	while (time(NULL) - start < 60) {
 		if (fork() == 0) {
 			usleep(10000);
 			_exit(0);
 		}
 		wait(NULL);
 	}
 
 	for (i = 0; i < 2; i++)
 		if ((rc = pthread_join(tid[i], NULL)) != 0)
 			errc(1, rc, "pthread_join");
 	_exit(0);
 }
 
 int
 testing(unsigned long maxl)
 {
 	struct passwd *pw;
 	struct rlimit rl;
 	rlim_t maxlock;
 	time_t start;
 	int i;
 
 	maxlock = maxl;
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	rl.rlim_max = rl.rlim_cur = 0;
 	if (setrlimit(RLIMIT_CORE, &rl) == -1)
 		warn("setrlimit");
 
 	if (getrlimit(RLIMIT_MEMLOCK, &rl) == -1)
 		warn("getrlimit");
 	if (maxlock <= 0)
 		errx(1, "Argument is %jd", maxlock);
 	maxlock = (maxlock / 10 * 8) / PARALLEL * PAGE_SIZE;
 	if (maxlock < rl.rlim_cur) {
 		rl.rlim_max = rl.rlim_cur = maxlock;
 		if (setrlimit(RLIMIT_MEMLOCK, &rl) == -1)
 			warn("setrlimit");
 	}
 
 	for (i = 0; i < N; i++)
 		r[i] = arc4random();
 
 	start = time(NULL);
 	while (time(NULL) - start < RUNTIME) {
 		for (i = 0; i < PARALLEL; i++) {
 			if (fork() == 0)
 				test();
 		}
 
 		for (i = 0; i < PARALLEL; i++)
 			wait(NULL);
 	}
 
 	_exit(0);
 }
 
 int
 main(int argc, char *argv[])
 {
 	pid_t pid;
 	size_t len;
 	int i, loops, s, status;
 	unsigned long max_wired;
 	unsigned int wire_count, wire_count_old;
 
 	s = 0;
 	if (argc != 2)
 		errx(1, "Usage: %s <loops>", argv[0]);
 	loops = atoi(argv[1]);
 
 	len = sizeof(max_wired);
 	if (sysctlbyname("vm.max_user_wired", &max_wired, &len, NULL, 0) != 0)
 		err(1, "vm.max_user_wired");
 
 	len = sizeof(wire_count);
 	if (sysctlbyname("vm.stats.vm.v_user_wire_count", &wire_count, &len,
 	    NULL, 0) != 0)
 		err(1, "vm.stats.vm.v_user_wire_count");
 
 	for (i = 0; i < loops; i++) {
 		wire_count_old = wire_count;
 
 		if ((pid = fork()) == 0)
 			testing(max_wired);
 		if (waitpid(pid, &status, 0) != pid)
 			err(1, "waitpid(%d)", pid);
 		if (status != 0)
 			errx(1, "Exit status %d from pid %d\n", status, pid);
 
 		len = sizeof(wire_count);
 		if (sysctlbyname("vm.stats.vm.v_user_wire_count", &wire_count, &len,
 		    NULL, 0) != 0)
 			err(1, "vm.stats.vm.v_user_wire_count");
 		fprintf(stderr, "vm.stats.vm.v_user_wire_count was %d, is %d. %d\n",
 		    wire_count_old, wire_count, wire_count - wire_count_old);
 	}
 
 	return (s);
 }
diff --git a/tools/test/stress2/misc/mountu.sh b/tools/test/stress2/misc/mountu.sh
index abd3c744d160..95043e634ef1 100755
--- a/tools/test/stress2/misc/mountu.sh
+++ b/tools/test/stress2/misc/mountu.sh
@@ -1,288 +1,288 @@
 #!/bin/sh
 
 #
 # SPDX-License-Identifier: BSD-2-Clause
 #
 # Copyright (c) 2012 Peter Holm <pho@FreeBSD.org>
 # Copyright (c) 2019 Dell EMC Isilon
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Change mount point from rw to ro with a file mapped rw
 # Currently fails for NFS
 
 # Page fault seen:
 # https://people.freebsd.org/~pho/stress/log/mountu.txt
 # Fixed by: r285039.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 here=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $here/$0 > mountu.c
 mycc -o mountu -Wall -Wextra -O2 mountu.c || exit 1
 rm -f mountu.c
 
 pstat() {
 	local pid
 	pid=`ps ax | grep -v grep | grep /tmp/mountu | awk '{print $1}'`
 	[ -n "$pid" ] && procstat -v $pid
 }
 
 ck() {
 	if mount | grep $mntpoint | grep -q "read-only"; then
 		if pstat $!| awk "\$2 == \"$map\"" | grep -q " rw-"; then
 			echo
 			echo "$1 difference"
 			mount | grep $mntpoint
 			printf "RW mount mapping and RO mount mapping:\n%s\n" "$r"
 			pstat $! | awk "\$2 == \"$map\""
 			status=$((status + 1))
 		fi
 	else
 		echo "$1 mount point RO did not succeed"
 		mount | grep $mntpoint
 		status=$((status + 1))
 	fi
 }
 
 status=0
 file=$mntpoint/mountu.sh.file
 mapfile=/tmp/mountu.sh.map
 mount | grep -q "$mntpoint " && umount $mntpoint
 mdconfig -l | grep -q $mdstart && mdconfig -d -u $mdstart
 mdconfig -a -t swap -s 100m -u $mdstart
 gpart create -s bsd md$mdstart > /dev/null
 gpart add -t freebsd-ufs md$mdstart > /dev/null
 part=a
 newfs $newfs_flags md${mdstart}$part > /dev/null
 mount /dev/md${mdstart}$part $mntpoint
 chmod 777 $mntpoint
 
 # ufs
 exec 5>$mapfile
 /tmp/mountu UFS $file &
 pid=$!
 sleep 1
 map=`cat $mapfile`; rm $mapfile; exec 5>&-
 
 r=`pstat $! | awk "\\$2 == \"$map\""`
 mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint
 ck UFS
 mount -u -o rw $mntpoint
 rm -f $file
 wait $pid
 s=$?
 [ $s -ne 139 ] && { echo "UFS exit status is $s"; status=1; }
 while mount | grep -q "$mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 mdconfig -d -u $mdstart
 
 # nfs
 if ping -c 2 `echo $nfs_export | sed 's/:.*//'` > /dev/null 2>&1; then
 	mount -t nfs -o tcp -o retrycnt=3 -o intr,soft -o rw $nfs_export \
 	    $mntpoint
 	sleep .2
 	rm -f $file
 	/tmp/mountu NFS $file &
 	pid=$!
 	sleep 1
 
 	r=`pstat $! | awk "\\$2 == \"$map\""`
 	mount -u -o ro $mntpoint 2>/dev/null ||
 	    mount -fu -o ro $mntpoint 2>/dev/null
 	ck NFS
 	wait $pid
 	s=$?
 	[ $s -ne 139 ] && { echo "NFS exit status is $s"; status=1; }
 
 	mount -u -o rw $mntpoint 2>/dev/null
 	sleep .2
 	[ -f $file ] && rm -f $file
 	umount $mntpoint || umount $mntpoint
 fi
 
 # msdos
 if [ -x /sbin/mount_msdosfs ]; then
 	mdconfig -a -t swap -s 100m -u $mdstart
 	gpart create -s bsd md$mdstart > /dev/null
 	gpart add -t freebsd-ufs md$mdstart > /dev/null
 	part=a
 	newfs_msdos -F 16 -b 8192 /dev/md${mdstart}$part > /dev/null 2>&1
 	mount_msdosfs -m 777 /dev/md${mdstart}$part $mntpoint
 	/tmp/mountu MSDOS $file &
 	pid=$!
 
 	sleep 1
 	r=`pstat $! | awk "\\$2 == \"$map\""`
 	mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint
 	ck MSDOS
 	wait $pid
 	s=$?
 	[ $s -ne 139 ] && { echo "MSDOS exit status is $s"; status=1; }
 	mount -u -o rw $mntpoint
 	rm -f $file
 
 	while mount | grep -q "$mntpoint "; do
 		umount $mntpoint || sleep 1
 	done
 	mdconfig -d -u $mdstart
 fi
 
 # tmpfs
 mount -t tmpfs null $mntpoint
 chmod 777 $mntpoint
 
 /tmp/mountu TMPFS $file &
 pid=$!
 
 sleep 1
 r=`pstat $! | awk "\\$2 == \"$map\""`
 mount -u -o ro $mntpoint 2>/dev/null || mount -fu -o ro $mntpoint
 ck TMPFS
 sleep 1
 mount -u -o rw $mntpoint
 rm -f $file
 wait $pid
 s=$?
 [ $s -ne 139 ] && { echo "TMPFS exit status is $s"; status=1; }
 while mount | grep -q "$mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 
 rm -f /tmp/mountu
 exit 0
 EOF
 /* kib@ noted:
    UFS/NFS/msdosfs reclaim vnode on rw->ro forced remount, and
    change the type of the underying object to OBJT_DEAD, but leave
    the pages on the object queue and installed in the page tables.
    Applications can read/write already mapped pages, but cannot
    page in new pages, cannot observe possible further modifications
    to already mapped pages (if ro->rw remount happen later), and
    their updates to pages are not flushed to file.
 
    It is impossible to mimic this behaviour for tmpfs.
  */
 #include <sys/param.h>
 #include <sys/mman.h>
 #include <sys/ucontext.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define STARTADDR 0x0U
 #define ADRSPACE 0x0640000U
 
 static void
 sighandler(int signo, siginfo_t *si, void *uc1)
 {
 	ucontext_t *uc;
 
 	uc = uc1;
 	printf("SIG%s at %p, addr %p\n", sys_signame[signo], si->si_addr,
 #if defined(__i386__)
 	    (void *)uc->uc_mcontext.mc_eip);
 #else
 	    (void *)uc->uc_mcontext.mc_rip);
 #endif
 	exit(1);
 }
 
 int
 main(int argc __unused, char **argv)
 {
 	struct passwd *pw;
 	struct sigaction sa;
 	void *p;
 	size_t len;
 	int fd;
 	char *name, *path;
 	volatile char *c;
 
 	memset(&sa, 0, sizeof(sa));
 	sa.sa_sigaction = sighandler;
 	sa.sa_flags = SA_SIGINFO;
 	if (sigaction(SIGSEGV, &sa, NULL) == -1)
 		err(1, "sigaction(SIGSEGV)");
 	if (sigaction(SIGBUS, &sa, NULL) == -1)
 		err(1, "sigaction(SIGBUS)");
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	p = (void *)STARTADDR;
 	len = ADRSPACE;
 
 	name = argv[1];
 	path = argv[2];
 	if ((fd = open(path, O_CREAT | O_TRUNC | O_RDWR, 0622)) == -1)
 		err(1,"open(%s)", path);
 	if (ftruncate(fd, len) == -1)
 		err(1, "ftruncate");
 	if ((p = mmap(p, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) ==
 			MAP_FAILED) {
 		if (errno == ENOMEM) {
 			warn("mmap()");
 			return (1);
 		}
 		err(1, "mmap(1)");
 	}
 	dprintf(5, "%p\n", p);
 
 	for (c = p; (void *)c < p + len; c += PAGE_SIZE) {
 		*c = 1;
 	}
 
 	close(fd);
 	sleep(5);
 	fprintf(stderr, "%s: Late read start.\n", name);
 	for (c = p; (void *)c < p + len; c += PAGE_SIZE) {
 		*c;
 	}
 	fprintf(stderr, "%s: Late read complete.\n", name);
 
 	fprintf(stderr, "%s: Late write start.\n", name);
 	for (c = p; (void *)c < p + len; c += PAGE_SIZE) {
 		*c = 1;
 	}
 	fprintf(stderr, "%s: Late write complete.\n", name);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/msync.sh b/tools/test/stress2/misc/msync.sh
index 326c7e723774..df05875afb45 100755
--- a/tools/test/stress2/misc/msync.sh
+++ b/tools/test/stress2/misc/msync.sh
@@ -1,201 +1,201 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2013 Peter Holm <pho@FreeBSD.org>
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # msync(2) / mlockall(2) test scenario.
 # "panic: vm_fault_copy_wired: page missing" seen.
 # http://people.freebsd.org/~pho/stress/log/msync.txt
 # Fixed in r253189.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 dir=/tmp
 odir=`pwd`
 cd $dir
 sed '1,/^EOF/d' < $odir/$0 > $dir/msync.c
 mycc -o msync -Wall -Wextra msync.c -lpthread || exit 1
 rm -f msync.c
 cd $odir
 
 /tmp/msync &
 sleep 180
 while pkill -9 msync; do :; done
 wait
 rm -f /tmp/msync
 exit
 
 EOF
 #include <sys/types.h>
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <signal.h>
 #include <sys/mman.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 int syscallno = SYS_msync;
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 u_int32_t r[N];
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(1);
 }
 
 unsigned long
 makearg(void)
 {
 	unsigned int i;
 	unsigned long val;
 
 	val = arc4random();
 	i   = arc4random() % 100;
 	if (i < 20)
 		val = val & 0xff;
 	if (i >= 20 && i < 40)
 		val = val & 0xffff;
 	if (i >= 40 && i < 60)
 		val = (unsigned long)(r) | (val & 0xffff);
 #if defined(__LP64__)
 	if (i >= 60) {
 		val = (val << 32) | arc4random();
 		if (i > 80)
 			val = val & 0x00007fffffffffffUL;
 	}
 #endif
 
 	return(val);
 }
 
 void *
 calls(void *arg __unused)
 {
 	int i, num;
 	unsigned long arg1, arg2, arg3;
 
 	usleep(1000);
 	num = syscallno;
 	for (i = 0; i < 500; i++) {
 		arg1 = makearg();
 		arg2 = makearg();
 #if 0
 		arg3 = makearg();
 		arg3 = arg3 & ~MS_INVALIDATE;	/* No problem seen */
 #else
 		arg3 = MS_INVALIDATE;		/* panic */
 #endif
 
 #if 0
 		fprintf(stderr, "%2d : syscall(%3d, 0x%lx, 0x%lx, 0x%lx)\n",
 			i, num, arg1, arg2, arg3);
 		usleep(50000);
 #endif
 		alarm(1);
 		syscall(num, arg1, arg2, arg3);
 		num = 0;
 	}
 
 	return (0);
 }
 void
 wd(void)
 {
 	int i;
 
 	if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0)
 		err(1, "mlockall failed");
 
 	for (i = 0; i < 800; i++) {
 		if (fork() == 0) {
 			usleep(20000);
 			_exit(0);
 		}
 		wait(NULL);
 		usleep(100000);
 	}
 
 	_exit(0);
 }
 
 int
 main(void)
 {
 	struct passwd *pw;
 	pthread_t cp[50];
 	int e, i, j;
 
 	if (fork() == 0)
 		wd();
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
 
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	alarm(180);
 	for (i = 0; i < 8000; i++) {
 		if (fork() == 0) {
 			for (j = 0; j < N; j++)
 				r[j] = arc4random();
 			for (j = 0; j < 50; j++)
 				if ((e = pthread_create(&cp[j], NULL, calls, NULL)) != 0)
 					errc(1, e, "pthread_create");
 
 			for (j = 0; j < 50; j++)
 				pthread_join(cp[j], NULL);
 			_exit(0);
 		}
 		wait(NULL);
 	}
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/pread.sh b/tools/test/stress2/misc/pread.sh
index 24ee2efb696a..985d3f643df1 100755
--- a/tools/test/stress2/misc/pread.sh
+++ b/tools/test/stress2/misc/pread.sh
@@ -1,189 +1,189 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2011 Peter Holm <pho@FreeBSD.org>
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # pread(2) fuzzing inspired by the iknowthis test suite
 # by Tavis Ormandy <taviso  cmpxchg8b com>
 
 # Fixed in r227527.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 here=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $here/$0 > pread.c
 mycc -o pread -Wall -Wextra pread.c
 rm -f pread.c
 
 mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint
 mdconfig -l | grep -q md$mdstart &&  mdconfig -d -u $mdstart
 
 mount -t tmpfs tmpfs $mntpoint
 cp -a /usr/include $mntpoint
 echo "Testing tmpfs(4)"
 /tmp/pread $mntpoint
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 
 echo "Testing fdescfs(4)"
 mount -t fdescfs null /dev/fd
 for i in `jot 100`; do
 	/tmp/pread /dev/fd
 done
 
 while mount | grep -q "on /dev/fd "; do
 	umount /dev/fd || sleep 1
 done
 
 echo "Testing procfs(4)"
 mount -t procfs procfs $mntpoint
 /tmp/pread $mntpoint
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 
 mdconfig -a -t swap -s 1g -u $mdstart || exit 1
 newfs $newfs_flags md$mdstart > /dev/null
 mount /dev/md$mdstart $mntpoint
 cp -a /usr/include $mntpoint
 echo "Testing FFS"
 /tmp/pread $mntpoint
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 mdconfig -d -u $mdstart
 
 mount -t nullfs /bin $mntpoint
 echo "Testing nullfs(4)"
 /tmp/pread $mntpoint
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 
 echo "Testing procfs(4)"
 mount -t procfs procfs $mntpoint
 /tmp/pread $mntpoint
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 
 echo "Testing devfs(8)"
 mount -t devfs devfs $mntpoint
 /tmp/pread $mntpoint
 while mount | grep -q "on $mntpoint "; do
 	umount $mntpoint || sleep 1
 done
 
 rm -f /tmp/pread
 exit 0
 EOF
 #include <sys/types.h>
 #include <strings.h>
 #include <dirent.h>
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <sys/uio.h>
 #include <unistd.h>
 #include <sys/wait.h>
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(1);
 }
 
 int
 test(char *path)
 {
 
 	FTS		*fts;
 	FTSENT		*p;
 	int		ftsoptions;
 	char		*args[2];
 	int buf[64], fd;
 
 	signal(SIGSEGV, hand);
 	signal(SIGABRT, hand);
 	ftsoptions = FTS_PHYSICAL;
 	args[0] = path;
 	args[1] = 0;
 
 	if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 		err(1, "fts_open");
 
 	while ((p = fts_read(fts)) != NULL) {
 		if ((fd = open(p->fts_path, O_RDONLY)) == -1) {
 			if (errno != EACCES && errno != ENXIO)
 				warn("open(%s)", p->fts_path);
 			continue;
 		}
 		alarm(1);
 		pread(fd, (void *)0xdeadc0de, 0x7ffffff, 0xffffffff);
 		pread(fd, buf, 0x7ffffff, 0xffffffff);
 		pread(fd, buf, sizeof(buf), 0xffffffff);
 		pread(fd, buf, sizeof(buf), 0);
 		close(fd);
 	}
 	fts_close(fts);
 
 	exit(0);
 }
 
 int
 main(int argc __unused, char **argv)
 {
 	int i;
         struct passwd *pw;
 
         if ((pw = getpwnam("nobody")) == NULL)
                 err(1, "no such user: nobody");
 
-        if (setgroups(1, &pw->pw_gid) ||
+        if (setgroups(0, NULL) ||
             setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
             seteuid(pw->pw_uid) || setuid(pw->pw_uid))
                 err(1, "Can't drop privileges to \"nobody\"");
         endpwent();
 
 	if (daemon(0, 0) == -1)
 		err(1, "daemon()");
 
 	for (i = 0; i < 10; i++) {
 		if (fork() == 0)
 			test(argv[1]);
 		wait(NULL);
 	}
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/sched.sh b/tools/test/stress2/misc/sched.sh
index 1a1db70eb38a..8b33d7b16094 100755
--- a/tools/test/stress2/misc/sched.sh
+++ b/tools/test/stress2/misc/sched.sh
@@ -1,160 +1,160 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2014 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 # Show scheduler fairness for ULE vs. 4BSD.
 
 . ../default.cfg
 
 here=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $here/$0 > sched.c
 mycc -o sched -Wall -Wextra -O0 sched.c || exit 1
 rm -f sched.c
 cd $here
 
 mount | grep $mntpoint | grep -q /dev/md && umount -f $mntpoint
 mdconfig -l | grep -q md$mdstart &&  mdconfig -d -u $mdstart
 
 mdconfig -a -t swap -s 1g -u $mdstart || exit 1
 newfs $newfs_flags md$mdstart > /dev/null
 mount /dev/md$mdstart $mntpoint
 chmod 777 $mntpoint
 
 cpus=`sysctl hw.ncpu | sed 's/.*: //'`
 uname -v
 (cd $mntpoint; /tmp/sched $((cpus + 1))) > /dev/null 2>&1 &
 sleep 30
 export LANG=C
 top -U nobody -d 1 | grep nobody | awk '{print $11}' | sed 's/%//' |
     ministat -A -w 73 | tail -1 | awk '{if ($NF > 1.0) exit 1}' ||
 { echo Broken; top -U nobody -d 1 | grep nobody; }
 killall sched
 wait
 
 for i in `jot 3`; do
 	echo "run #$i"
 	(cd $mntpoint; /tmp/sched $((cpus + 1)))
 done
 
 while mount | grep $mntpoint | grep -q /dev/md; do
 	umount $mntpoint || sleep 1
 done
 rm -f /tmp/sched
 mdconfig -d -u $mdstart
 exit
 EOF
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pwd.h>
 #include <sched.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N 100 * 1024 * 1024
 
 double r;
 int parallel;
 
 void
 work(void)
 {
 	struct passwd *pw;
 	struct timespec start, finish;
 	double d1, d2;
 	int i, j;
 	volatile char *cp;
 
 	while (access("rendezvous", R_OK) != 0)
 		usleep(1);
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "no such user: nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	d1 = d2 = 0;
 	cp = malloc(N);
 	clock_gettime(CLOCK_REALTIME_PRECISE, &start);
 	for (i = 0; i < 1; i++) {
 		for (j = 0; j < INT_MAX; j++) {
 			d1 = d1 + 1.0 / j;
 			d2 = d1 + 0.8 / j;
 			if (j % 1000 == 0) {
 				cp[arc4random() % N] = j % 255;
 			}
 		}
 	}
 	r = d1 + d2;
 	clock_gettime(CLOCK_REALTIME_PRECISE, &finish);
 	timespecsub(&finish, &start, &finish);
 #if defined(DEBUG)
 	fprintf(stderr, "Elapsed time for pid %d: %.4f\n", getpid(),
 	    finish.tv_sec + (double)finish.tv_nsec / 1e9);
 #endif
 
 	_exit(0);
 }
 
 int
 main(int argc, char **argv)
 {
 	int fd, i;
 
 	if (argc == 2)
 		parallel = atoi(argv[1]);
 	else
 		errx(1, "Usage: %s <cpus>", argv[0]);
 
 	for (i = 0; i < parallel; i++) {
 		if (fork() == 0)
 			work();
 	}
 	if ((fd = open("rendezvous", O_CREAT, 0644)) == -1)
 		err(1, "open()");
 	close(fd);
 	for (i = 0; i < parallel; i++)
 		wait(NULL);
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/sigreturn3.sh b/tools/test/stress2/misc/sigreturn3.sh
index a2d865b73847..6795c4fd0846 100755
--- a/tools/test/stress2/misc/sigreturn3.sh
+++ b/tools/test/stress2/misc/sigreturn3.sh
@@ -1,181 +1,181 @@
 #!/bin/sh
 
 #
 # SPDX-License-Identifier: BSD-2-Clause
 #
 # Copyright (c) 2022 Peter Holm <pho@FreeBSD.org>
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Fatal trap -4186856: UNKNOWN while in kernel mode
 # cpuid = 1; apic id = 01
 # error code              = 0xfbafcf8c
 # instruction pointer     = 0x79e4:0x4
 # stack pointer           = 0x28:0xffc0aff0
 # frame pointer           = 0x28:0x204620d4
 # code segment            = base 0x0, limit 0x0, type 0x0
 #                         = DPL 0, pres 0, def32 0, gran 0
 # processor eflags        = trace trap,  at 0x3b/frame 0xffc0340c
 # KDB: enter: panic
 # [ thread pid 15631 tid 114622 ]
 # Stopped at      kdb_enter+0x34: movl    $0,kdb_why
 # db>
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 prog=sigreturn3
 
 cat > /tmp/$prog.c <<EOF
 #include <sys/types.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pthread_np.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N 4096
 #define RUNTIME 120
 #define THREADS 1
 
 static uint32_t r[N];
 
 static void
 hand(int i __unused) {	/* handler */
 	exit(1);
 }
 
 static void *
 churn(void *arg __unused)
 {
 	time_t start;
 
 	pthread_set_name_np(pthread_self(), __func__);
 	start = time(NULL);
 	while (time(NULL) - start < 10) {
 		arc4random_buf(r, sizeof(r));
 		usleep(100);
 	}
 	return(NULL);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	time_t start;
 
 	start = time(NULL);
 	while (time(NULL) - start < 10) {
 		arc4random_buf(r, sizeof(r));
 		alarm(1);
 		syscall(SYS_sigreturn, r);
 	}
 
 	return (NULL);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	struct rlimit limit;
 	pid_t pid;
 	pthread_t rp, cp[THREADS];
 	time_t start;
 	int e, j;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
 
 	if (getenv("USE_ROOT") && argc == 2)
 		fprintf(stderr, "Running syscall4 as root for %s.\n",
 				argv[1]);
 	else {
-		if (setgroups(1, &pw->pw_gid) ||
+		if (setgroups(0, NULL) ||
 		    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 		    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 			err(1, "Can't drop privileges to \"nobody\"");
 		endpwent();
 	}
 
 	limit.rlim_cur = limit.rlim_max = 1000;
 #if defined(RLIMIT_NPTS)
 	if (setrlimit(RLIMIT_NPTS, &limit) < 0)
 		err(1, "setrlimit");
 #endif
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	if (daemon(1, 1) == -1)
 		err(1, "daemon()");
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		if ((pid = fork()) == 0) {
 			if ((e = pthread_create(&rp, NULL, churn, NULL)) != 0)
 			errc(1, e, "pthread_create");
 			for (j = 0; j < THREADS; j++)
 				if ((e = pthread_create(&cp[j], NULL, calls,
 				    NULL)) != 0)
 					errc(1, e, "pthread_create");
 			for (j = 0; j < THREADS; j++)
 				pthread_join(cp[j], NULL);
 
 			if ((e = pthread_kill(rp, SIGINT)) != 0)
 				errc(1, e, "pthread_kill");
 			if ((e = pthread_join(rp, NULL)) != 0)
 				errc(1, e, "pthread_join");
 			_exit(0);
 		}
 		waitpid(pid, NULL, 0);
 	}
 
 	return (0);
 }
 EOF
 
 cd /tmp
 cc -o $prog -Wall -Wextra -O0 $prog.c -lpthread || exit 1
 start=`date +%s`
 while [ $((`date +%s` - start)) -lt 300 ]; do
 	./$prog > /dev/null 2>&1
 done
 rm -f /tmp/$prog /tmp/$prog.c /tmp/$prog.core
 exit 0
diff --git a/tools/test/stress2/misc/sigreturn4.sh b/tools/test/stress2/misc/sigreturn4.sh
index c77140de0518..90ee16777e03 100755
--- a/tools/test/stress2/misc/sigreturn4.sh
+++ b/tools/test/stress2/misc/sigreturn4.sh
@@ -1,207 +1,207 @@
 #!/bin/sh
 
 # panic: vm_fault_lookup: fault on nofault entry, addr: 0
 # cpuid = 2
 # time = 1661698922
 # KDB: stack backtrace:
 # db_trace_self_wrapper(b,2931e740,2931e742,ffc0ddb8,190431,...) at db_trace_self_wrapper+0x28/frame 0xffc0dd24
 # vpanic(150acba,ffc0dd60,ffc0dd60,ffc0de20,12cc155,...) at vpanic+0xf4/frame 0xffc0dd40
 # panic(150acba,14ec1ab,0,146253d,1430,...) at panic+0x14/frame 0xffc0dd54
 # vm_fault(1e360c8,0,4,0,0) at vm_fault+0x1725/frame 0xffc0de20
 # vm_fault_trap(1e360c8,3b,4,0,0,0) at vm_fault_trap+0x52/frame 0xffc0de48
 # trap_pfault(3b,0,0) at trap_pfault+0x176/frame 0xffc0de94
 # trap(ffc0df6c,8,28,28,19156000,...) at trap+0x2d9/frame 0xffc0df60
 # calltrap() at 0xffc031ef/frame 0xffc0df60
 # --- trap 0xc, eip = 0x3b, esp = 0xffc0dfac, ebp = 0xffc0340c ---
 # (null)() at 0x3b/frame 0xffc0340c
 # KDB: enter: panic
 # [ thread pid 54680 tid 102765 ]
 # Stopped at      kdb_enter+0x34: movl    $0,kdb_why
 # db> x/s version
 # version:        FreeBSD 14.0-CURRENT #0 main-n257606-9ea2716b775-dirty: Thu Aug 25 10:47:45 CEST 2022
 # pho@mercat1.netperf.freebsd.org:/media/ob
 # j/usr/src/i386.i386/sys/PHO\012
 # db> show proc
 # Process 54680 (date) at 0x28905d50:
 #  state: NORMAL
 #  uid: 0  gids: 0, 0, 5
 #  parent: pid 785 at 0x26c14000
 #  ABI: FreeBSD ELF32
 #  flag: 0x10004002  flag2: 0
 #  arguments: date +%s
 #  reaper: 0x18c710a4 reapsubtree: 1
 #  sigparent: 20
 #  vmspace: 0x29332100
 #    (map 0x29332100)
 #    (map.pmap 0x29332174)
 #    (pmap 0x293321b0)
 #  threads: 1
 # 102765                   Run     CPU 2               date
 # db>
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 prog=sigreturn4
 
 cat > /tmp/$prog.c <<EOF
 #include <sys/types.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 
 #include <ucontext.h>
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define RUNTIME 120
 #define THREADS 1
 
 static void
 hand(int i __unused) {	/* handler */
 	_exit(1);
 }
 
 static long
 random_long(long mi, long ma)
 {
         return (arc4random()  % (ma - mi + 1) + mi);
 }
 
 static void
 flip(void *ap, size_t len)
 {
 	unsigned char *cp;
 	int byte;
 	unsigned char bit, buf, mask, old __unused;
 
 	cp = (unsigned char *)ap;
 	byte = random_long(0, len);
 	bit = random_long(0,7);
 	mask = ~(1 << bit);
 	buf = cp[byte];
 	old = cp[byte];
 	buf = (buf & mask) | (~buf & ~mask);
 	cp[byte] = buf;
 }
 
 static void *
 churn(void *arg __unused)
 {
 	time_t start;
 
 	start = time(NULL);
 	while (time(NULL) - start < 10) {
 		usleep(100);
 	}
 	return(NULL);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	time_t start;
 	ucontext_t uc;
 	int n;
 
 	start = time(NULL);
 	while (time(NULL) - start < 10) {
 		n = 0;
 		if (getcontext(&uc) == -1)
 			err(1, "getcontext");
 		n++;
 
 		if (n == 1) {
 			flip(&uc, sizeof(uc));
 			alarm(1);
 			if (sigreturn(&uc) == -1)
 				err(1, "sigreturn()");
 		} else
 			break;
 	}
 	return (NULL);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	struct rlimit limit;
 	pid_t pid;
 	pthread_t rp, cp[THREADS];
 	time_t start;
 	int e, j;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
 
 	if (getenv("USE_ROOT") && argc == 2)
 		fprintf(stderr, "Running sigreturn4 as root for %s.\n",
 				argv[1]);
 	else {
-		if (setgroups(1, &pw->pw_gid) ||
+		if (setgroups(0, NULL) ||
 		    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 		    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 			err(1, "Can't drop privileges to \"nobody\"");
 		endpwent();
 	}
 
 	limit.rlim_cur = limit.rlim_max = 1000;
 #if defined(RLIMIT_NPTS)
 	if (setrlimit(RLIMIT_NPTS, &limit) < 0)
 		err(1, "setrlimit");
 #endif
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	if (daemon(1, 1) == -1)
 		err(1, "daemon()");
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		if ((pid = fork()) == 0) {
 			if ((e = pthread_create(&rp, NULL, churn, NULL)) != 0)
 			errc(1, e, "pthread_create");
 			for (j = 0; j < THREADS; j++)
 				if ((e = pthread_create(&cp[j], NULL, calls,
 				    NULL)) != 0)
 					errc(1, e, "pthread_create");
 			for (j = 0; j < THREADS; j++)
 				pthread_join(cp[j], NULL);
 
 			if ((e = pthread_kill(rp, SIGINT)) != 0)
 				errc(1, e, "pthread_kill");
 			if ((e = pthread_join(rp, NULL)) != 0)
 				errc(1, e, "pthread_join");
 			_exit(0);
 		}
 		waitpid(pid, NULL, 0);
 	}
 
 	return (0);
 }
 EOF
 
 cd /tmp
 cc -o $prog -Wall -Wextra -O0 $prog.c -lpthread || exit 1
 start=`date +%s`
 while [ $((`date +%s` - start)) -lt 300 ]; do
 	./$prog > /dev/null 2>&1
 done
 rm -f /tmp/$prog /tmp/$prog.c /tmp/$prog.core
 exit 0
diff --git a/tools/test/stress2/misc/syscall4.sh b/tools/test/stress2/misc/syscall4.sh
index 3937d45c0303..92150c782ac1 100755
--- a/tools/test/stress2/misc/syscall4.sh
+++ b/tools/test/stress2/misc/syscall4.sh
@@ -1,381 +1,381 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2011-2013 Peter Holm
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # Threaded syscall(2) fuzz test inspired by the iknowthis test suite
 # by Tavis Ormandy <taviso  cmpxchg8b com>
 
 # Usage: syscall4.sh [syscall number]
 #	Without an argument random syscall numbers are tested.
 #	With an argument only the specified syscall number is tested.
 
 # Sample problems found:
 # Thread stuck in stopprof.
 # http://people.freebsd.org/~pho/stress/log/kostik732.txt
 # Fixed by r275121.
 
 # panic: td 0xcbe1ac40 is not suspended.
 # https://people.freebsd.org/~pho/stress/log/kostik807.txt
 # Fixed by r282944.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > syscall4.c
 sed -i '' -e "s#MNTPOINT#$mntpoint#" syscall4.c
 rm -f /tmp/syscall4
 mycc -o syscall4 -Wall -Wextra -O2 -g syscall4.c -lpthread || exit 1
 rm -f syscall4.c
 
 kldstat -v | grep -q sysvmsg  || $stress2tools/kldload.sh sysvmsg
 kldstat -v | grep -q sysvsem  || $stress2tools/kldload.sh sysvsem
 kldstat -v | grep -q sysvshm  || $stress2tools/kldload.sh sysvshm
 kldstat -v | grep -q aio      || $stress2tools/kldload.sh aio
 kldstat -v | grep -q mqueuefs || $stress2tools/kldload.sh mqueuefs
 
 mount | grep -q "on $mntpoint " && umount -f $mntpoint
 [ -c /dev/md$mdstart ] && mdconfig -d -u $mdstart
 
 mdconfig -a -t swap -s 2g -u $mdstart || exit 1
 newfs $newfs_flags -n md$mdstart > /dev/null
 mount /dev/md$mdstart $mntpoint
 chmod 777 $mntpoint
 
 [ -z "$noswap" ] &&
     daemon sh -c "(cd $odir/../testcases/swap; ./swap -t 10m -i 20 -k)" > \
     /dev/null
 sleeptime=${sleeptime:-12}
 st=`date '+%s'`
 while [ $((`date '+%s'` - st)) -lt $((10 * sleeptime)) ]; do
 	(cd $mntpoint; /tmp/syscall4 $* 1>>stdout 2>>stderr) &
 	start=`date '+%s'`
 	while [ $((`date '+%s'` - start)) -lt $sleeptime ]; do
 		pgrep syscall4 > /dev/null || break
 		sleep .5
 	done
 	while pkill -9 syscall4; do :; done
 	wait
 	ipcs | grep nobody | awk '/^(q|m|s)/ {print " -" $1, $2}' |
 	    xargs -L 1 ipcrm
 done
 while pkill -9 swap; do :; done
 while pkill -9 syscall4; do :; done
 
 for i in `jot 10`; do
 	mount | grep -q md$mdstart  && \
 		umount $mntpoint && mdconfig -d -u $mdstart && break
 	sleep 10
 done
 if mount | grep -q md$mdstart; then
 	fstat $mntpoint
 	echo "umount $mntpoint failed"
 	exit 1
 fi
 rm -f /tmp/syscall4
 exit 0
 EOF
 #include <sys/types.h>
 #include <sys/event.h>
 #include <sys/resource.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/wait.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #if defined(__FreeBSD__)
 #include <pthread_np.h>
 #define	__NP__
 #endif
 #include <pwd.h>
 #include <signal.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 static int ignore[] = {
 	SYS_syscall,
 	SYS_exit,
 	SYS_fork,
 	11,			/* 11 is obsolete execv */
 	SYS_reboot,
 	SYS_vfork,
 	109,			/* 109 is old sigblock */
 	111,			/* 111 is old sigsuspend */
 	SYS_shutdown,
 	SYS___syscall,
 	216,			/* custom syscall */
 	SYS_rfork,
 	SYS_mac_syscall,
 };
 
 static int fd[900], fds[2], kq, socketpr[2];
 #ifndef nitems
 #define nitems(x) (sizeof((x)) / sizeof((x)[0]))
 #endif
 #define N 4096
 #define MAGIC 1664
 #define RUNTIME 120
 #define THREADS 50
 
 static uint32_t r[N];
 static int magic1, syscallno, magic2;
 
 static int
 random_int(int mi, int ma)
 {
         return (arc4random()  % (ma - mi + 1) + mi);
 }
 
 static void
 hand(int i __unused) {	/* handler */
 	exit(1);
 }
 
 static unsigned long
 makearg(void)
 {
 	unsigned int i;
 	unsigned long val;
 
 	val = arc4random();
 	i   = arc4random() % 100;
 	if (i < 20)
 		val = val & 0xff;
 	if (i >= 20 && i < 40)
 		val = val & 0xffff;
 	if (i >= 40 && i < 60)
 		val = (unsigned long)(r) | (val & 0xffff);
 #if defined(__LP64__)
 	if (i >= 60) {
 		val = (val << 32) | arc4random();
 		if (i > 80)
 			val = val & 0x00007fffffffffffUL;
 	}
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 	FTS *fts;
 	FTSENT *p;
 	time_t start;
 	int ftsoptions, i, numfiles;
 	char *args[] = {
 	    "/dev",
 	    "/proc",
 	    "MNTPOINT",
 	    "mnt2",
 	    ".",
 	    NULL,
 	};
 
 #ifdef __NP__
 	pthread_set_name_np(pthread_self(), __func__);
 #endif
 	numfiles = 0;
 	ftsoptions = FTS_PHYSICAL;
 	start = time(NULL);
 	while (time(NULL) - start < 2) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 
 		if (pipe(fds) == -1)
 			err(1, "pipe()");
 		if (socketpair(PF_UNIX, SOCK_SEQPACKET, 0, socketpr) == -1)
 			err(1, "socketpair()");
 		kq = kqueue();
 
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) ==
 				    -1)
 					if ((fd[i] = open(p->fts_path,
 					    O_RDONLY)) == -1)
 						continue;
 			i++;
 			i = i % nitems(fd);
 			if (numfiles++ < 10) {
 				fprintf(stderr, "%d: pts_path = %s\n",
 				    numfiles, p->fts_path);
 			}
 		}
 
 		if (fts_close(fts) == -1)
 			warn("fts_close()");
 		sleep(1);
 		close(socketpr[0]);
 		close(socketpr[1]);
 		close(fds[0]);
 		close(fds[1]);
 		close(kq);
 	}
 	return(NULL);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	time_t start;
 	int i __unused, j, num;
 	unsigned long arg1, arg2, arg3, arg4, arg5, arg6, arg7;
 
 #ifdef __NP__
 	pthread_set_name_np(pthread_self(), __func__);
 #endif
 	start = time(NULL);
 	for (i = 0; time(NULL) - start < 10; i++) {
 		num = syscallno;
 		while (num == 0) {
 			num = random_int(0, SYS_MAXSYSCALL);
 			for (j = 0; j < (int)nitems(ignore); j++)
 				if (num == ignore[j]) {
 					num = 0;
 					break;
 				}
 		}
 		arg1 = makearg();
 		arg2 = makearg();
 		arg3 = makearg();
 		arg4 = makearg();
 		arg5 = makearg();
 		arg6 = makearg();
 		arg7 = makearg();
 
 #if 0		/* Debug mode */
 		fprintf(stderr, "%2d : syscall(%3d, %lx, %lx, %lx, %lx, %lx,"
 		   " %lx, %lx)\n",
 			i, num, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
 		sleep(2);
 #endif
 		alarm(1);
 		syscall(num, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
 		num = 0;
 		if (magic1 != MAGIC || magic2 != MAGIC)
 			exit(1);
 	}
 
 	return (NULL);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	struct rlimit limit;
 	pthread_t rp, cp[THREADS];
 	time_t start;
 	int e, j;
 
 	magic1 = magic2 = MAGIC;
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
 
 	if (getenv("USE_ROOT") && argc == 2)
 		fprintf(stderr, "Running syscall4 as root for %s.\n",
 				argv[1]);
 	else {
-		if (setgroups(1, &pw->pw_gid) ||
+		if (setgroups(0, NULL) ||
 		    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 		    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 			err(1, "Can't drop privileges to \"nobody\"");
 		endpwent();
 	}
 
 	limit.rlim_cur = limit.rlim_max = 1000;
 #if defined(RLIMIT_NPTS)
 	if (setrlimit(RLIMIT_NPTS, &limit) < 0)
 		err(1, "setrlimit");
 #endif
 
 	signal(SIGALRM, hand);
 	signal(SIGILL,  hand);
 	signal(SIGFPE,  hand);
 	signal(SIGSEGV, hand);
 	signal(SIGBUS,  hand);
 	signal(SIGURG,  hand);
 	signal(SIGSYS,  hand);
 	signal(SIGTRAP, hand);
 
 	if (argc > 2) {
 		fprintf(stderr, "usage: %s [syscall-num]\n", argv[0]);
 		exit(1);
 	}
 	if (argc == 2) {
 		syscallno = atoi(argv[1]);
 		for (j = 0; j < (int)nitems(ignore); j++)
 			if (syscallno == ignore[j])
 				errx(0, "syscall #%d is on the ignore list.",
 				    syscallno);
 	}
 
 	if (daemon(1, 1) == -1)
 		err(1, "daemon()");
 
 	system("touch aaa bbb ccc; mkdir -p ddd");
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		if (fork() == 0) {
 			if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 				errc(1, e, "pthread_create");
 			usleep(1000);
 			for (j = 0; j < THREADS; j++)
 				if ((e = pthread_create(&cp[j], NULL, calls,
 				    NULL)) != 0)
 					errc(1, e, "pthread_create");
 			for (j = 0; j < THREADS; j++)
 				pthread_join(cp[j], NULL);
 
 			if ((e = pthread_kill(rp, SIGINT)) != 0)
 				errc(1, e, "pthread_kill");
 			exit(0);
 		}
 		wait(NULL);
 		usleep(10000);
 	}
 
 	return (0);
 }
diff --git a/tools/test/stress2/misc/tmpfs16.sh b/tools/test/stress2/misc/tmpfs16.sh
index 8cc3c3596a4e..683817ce6497 100755
--- a/tools/test/stress2/misc/tmpfs16.sh
+++ b/tools/test/stress2/misc/tmpfs16.sh
@@ -1,200 +1,200 @@
 #!/bin/sh
 
 #
 # Copyright (c) 2016 EMC Corp.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 # ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
 
 # A fuzz test using random file descriptors with random seeks.
 # "panic: Assertion (cookie & TMPFS_DIRCOOKIE_MASK) == cookie failed":
 # https://people.freebsd.org/~pho/stress/log/kostik922.txt
 # Fixed by r303916.
 
 [ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
 
 . ../default.cfg
 
 mount | grep -q "on $mntpoint " && umount -f $mntpoint
 mount -o size=1g -t tmpfs tmpfs $mntpoint
 RUNDIR=$mntpoint/stressX
 dir=$RUNDIR
 
 odir=`pwd`
 cd /tmp
 sed '1,/^EOF/d' < $odir/$0 > tmpfs16.c
 rm -f /tmp/tmpfs16
 mycc -o tmpfs16 -Wall -Wextra -O2 -g tmpfs16.c -lpthread || exit 1
 rm -f tmpfs16.c
 
 rm -rf $dir
 mkdir -p $dir
 chmod 777 $dir
 
 cd $dir
 jot 500 | xargs touch
 jot 500 | xargs chmod 666
 cd $odir
 
 (cd /tmp; /tmp/tmpfs16 $dir)
 e=$?
 
 rm -rf $dir
 umount $mntpoint
 
 rm -f /tmp/tmpfs16
 exit $e
 EOF
 #include <sys/param.h>
 #include <sys/resource.h>
 
 #include <err.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
 #include <libutil.h>
 #include <pthread.h>
 #include <pwd.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #define N (128 * 1024 / (int)sizeof(u_int32_t))
 #define RUNTIME 180
 #define THREADS 2
 
 static int fd[900];
 static u_int32_t r[N];
 static char *args[2];
 
 static unsigned long
 makearg(void)
 {
 	unsigned long val;
 
 	val = arc4random();
 #if defined(__LP64__)
 	val = (val << 31) | arc4random();
 	val = val & 0x00007fffffffffffUL;
 #endif
 
 	return(val);
 }
 
 static void *
 test(void *arg __unused)
 {
 	FTS *fts;
 	FTSENT *p;
 	int ftsoptions, i, n;
 
 	ftsoptions = FTS_PHYSICAL;
 
 	for (;;) {
 		for (i = 0; i < N; i++)
 			r[i] = arc4random();
 		if ((fts = fts_open(args, ftsoptions, NULL)) == NULL)
 			err(1, "fts_open");
 
 		i = n = 0;
 		while ((p = fts_read(fts)) != NULL) {
 			if (fd[i] > 0)
 				close(fd[i]);
 			if ((fd[i] = open(p->fts_path, O_RDWR)) == -1)
 				if ((fd[i] = open(p->fts_path, O_WRONLY)) == -1)
 				continue;
 			if (ftruncate(fd[i], 0) != 0)
 				err(1, "ftruncate");
 			i++;
 			i = i % nitems(fd);
 		}
 
 		if (fts_close(fts) == -1)
 			err(1, "fts_close()");
 		sleep(1);
 	}
 	return(0);
 }
 
 static void *
 calls(void *arg __unused)
 {
 	off_t offset;
 	time_t start;
 	int fd2;
 
 	start = time(NULL);
 	while ((time(NULL) - start) < RUNTIME) {
 		fd2 = makearg() % nitems(fd) + 3;
 		offset = makearg();
 		if (lseek(fd2, offset - 1, SEEK_SET) != -1) {
 			if (write(fd2, "x", 1) != 1)
 				if (errno != EBADF && errno != ENOSPC)
 					warn("write");
 		} else
 			if (errno != EBADF)
 				warn("lseek");
 		if (fsync(fd2) == -1)
 			if (errno != EBADF)
 				warn("x");
 
 	}
 
 	return (0);
 }
 
 int
 main(int argc, char **argv)
 {
 	struct passwd *pw;
 	pthread_t rp, cp[THREADS];
 	int e, i;
 
 	if (argc != 2) {
 		fprintf(stderr, "Usage: %s <dir>\n", argv[0]);
 		exit(1);
 	}
 	args[0] = argv[1];
 	args[1] = 0;
 
 	if ((pw = getpwnam("nobody")) == NULL)
 		err(1, "failed to resolve nobody");
-	if (setgroups(1, &pw->pw_gid) ||
+	if (setgroups(0, NULL) ||
 	    setegid(pw->pw_gid) || setgid(pw->pw_gid) ||
 	    seteuid(pw->pw_uid) || setuid(pw->pw_uid))
 		err(1, "Can't drop privileges to \"nobody\"");
 	endpwent();
 
 	if ((e = pthread_create(&rp, NULL, test, NULL)) != 0)
 		errc(1, e, "pthread_create");
 	usleep(1000);
 	for (i = 0; i < THREADS; i++)
 		if ((e = pthread_create(&cp[i], NULL, calls, NULL)) != 0)
 			errc(1, e, "pthread_create");
 	for (i = 0; i < THREADS; i++)
 		pthread_join(cp[i], NULL);
 
 	return (0);
 }