diff --git a/tools/test/stress2/misc/setrlimit.sh b/tools/test/stress2/misc/setrlimit.sh
new file mode 100755
index 000000000000..ea679f987510
--- /dev/null
+++ b/tools/test/stress2/misc/setrlimit.sh
@@ -0,0 +1,193 @@
+#!/bin/sh
+
+#
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# 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.
+#
+
+[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+
+# Test setrlimit() max file size and ftruncate()
+
+# Problem seen:
+# Testing UFS -O1
+# setrlimit: ftruncate(5413) did not fail. limit = 2791
+# Testing FFS -U
+# setrlimit: ftruncate(9956) did not fail. limit = 7880
+# Testing msdosfs
+# setrlimit: ftruncate(9033) did not fail. limit = 5884
+# Testing tmpfs
+# setrlimit: ftruncate(123) did not fail. limit = 86
+
+. ../default.cfg
+
+cat > /tmp/setrlimit.c <<EOF
+#include <sys/types.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static int signals;
+
+static void
+handler(int sig __unused)
+{
+#if defined(DEBUG)
+	fprintf(stderr, "Got signal SIGXFSZ\n");
+#endif
+	signals++;
+}
+
+void
+test(int argc, char *argv[])
+{
+	struct rlimit rlim;
+	rlim_t limit, sz;
+	struct sigaction act;
+	long pos;
+	int e, expected, fd;
+	char file[] = "setrlimit.file";
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s <FS size>\n", argv[0]);
+		exit(1);
+	}
+	expected = signals = 0;
+	sz = atol(argv[1]);
+	arc4random_buf(&limit, sizeof(limit));
+	if (limit < 0)
+		limit = -limit;
+	limit = limit % sz + 1;
+	rlim.rlim_cur = rlim.rlim_max = limit;
+	if (setrlimit(RLIMIT_FSIZE, &rlim) == -1)
+		err(1, "setrlimit(%ld)", limit);
+
+	act.sa_handler = handler;
+	act.sa_flags = 0;
+	sigemptyset(&act.sa_mask);
+	if (sigaction(SIGXFSZ, &act, NULL) != 0)
+		err(1, "sigaction");
+
+	if ((fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, DEFFILEMODE)) == -1)
+		err(1, "open(%s)", file);
+
+	e  = 0;
+	arc4random_buf(&pos, sizeof(pos));
+	if (pos < 0)
+		pos = -pos;
+	pos = pos % (limit * 2);
+	if (pos > limit)
+		expected = 1;
+	if (ftruncate(fd, pos) == -1) {
+		e = errno;
+		if (pos <= limit)
+			errc(1, e, "ftruncate(%ld), limit = %ld", pos, limit);
+	} else {
+		if (pos > limit)
+			errx(1, "ftruncate(%ld) did not fail. limit = %ld", pos, limit);
+	}
+
+	if (lseek(fd, limit - 1, SEEK_SET) == -1)
+		err(1, "lseek(limit - 1)");
+	if (write(fd, "a", 1) != 1)
+		err(1, "write() at limit - 1. limit = %ld", limit);
+
+	if (write(fd, "b", 1) != -1)
+		err(1, "write() at limit. limit = %ld", limit);
+	expected++;
+
+	/* Partial write test. No signal is expected */
+	if (lseek(fd, limit - 1, SEEK_SET) == -1)
+		err(1, "lseek(limit - 1)");
+	if (write(fd, "12", 2) != 1)
+		err(1, "write() at limit - 1. limit = %ld", limit);
+
+	if (signals != expected)
+		errx(1, "Expected %d signals, got %d", expected, signals);
+
+	close(fd);
+	unlink(file);
+}
+
+int
+main(int argc, char *argv[])
+{
+	int i;
+
+	for (i = 0; i < 100; i++)
+		test(argc, argv);
+
+}
+EOF
+
+here=`pwd`
+s=0
+cc -o /tmp/setrlimit -Wall -Wextra -O0 -g /tmp/setrlimit.c || exit 1
+
+mount | grep "on $mntpoint " | grep -q /dev/md && umount -f $mntpoint
+[ -c /dev/md$mdstart ] &&  mdconfig -d -u $mdstart
+
+echo "Testing UFS -O1"
+mdconfig -t swap -s 1g -u $mdstart
+newfs -O1 /dev/md$mdstart > /dev/null
+mount /dev/md$mdstart $mntpoint
+cd $mntpoint; /tmp/setrlimit 10000 ||  s=1
+cd $here
+umount $mntpoint
+mdconfig -d -u $mdstart
+
+echo "Testing FFS -U"
+mdconfig -t swap -s 1g -u $mdstart
+newfs -U /dev/md$mdstart > /dev/null
+mount /dev/md$mdstart $mntpoint
+cd $mntpoint; /tmp/setrlimit 10000 || s=$((s + 2))
+cd $here
+umount $mntpoint
+mdconfig -d -u $mdstart
+
+echo "Testing msdosfs"
+mdconfig -t swap -s 1g -u $mdstart
+newfs_msdos -F 32 -b 8192 /dev/md$mdstart > /dev/null 2>&1
+mount -t msdosfs /dev/md$mdstart $mntpoint
+cd $mntpoint; /tmp/setrlimit 10000 || s=$((s + 4))
+cd $here
+umount $mntpoint
+mdconfig -d -u $mdstart
+
+echo "Testing tmpfs"
+mount -o size=20000 -t tmpfs dummy $mntpoint
+cd $mntpoint; /tmp/setrlimit 10000 || s=$((s + 8))
+cd $here
+umount $mntpoint
+
+rm -f /tmp/setrlimit /tmp/setrlimit.c
+exit $s
diff --git a/tools/test/stress2/misc/setrlimit2.sh b/tools/test/stress2/misc/setrlimit2.sh
new file mode 100755
index 000000000000..f0b933158393
--- /dev/null
+++ b/tools/test/stress2/misc/setrlimit2.sh
@@ -0,0 +1,118 @@
+#!/bin/sh
+
+#
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# 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.
+#
+
+# Demonstrate that a mapped SHARED file can be updated past past LIMIT_FSIZE
+
+# Kostik wrote:
+# This one should be reproducible when you
+# - have file larger than e.g. RLIMIT_FSIZE
+# - mmaped it without closing the file descriptor
+# - dirty its pages beyond the limit
+# - then unmap
+# - then close the file descriptor.
+
+[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+
+. ../default.cfg
+
+cat > /tmp/setrlimit2.c <<EOF
+#include <sys/param.h>
+#include <sys/mman.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+static int signals;
+
+static void
+handler(int sig __unused)
+{
+	signals++;
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct rlimit rlim;
+	struct sigaction act;
+	struct stat st;
+	size_t len;
+	int error, fd, ps;
+	char *file, *p;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s <data file>\n", argv[0]);
+		exit(1);
+	}
+	act.sa_handler = handler;
+	act.sa_flags = 0;
+	sigemptyset(&act.sa_mask);
+	if (sigaction(SIGXFSZ, &act, NULL) != 0)
+		err(1, "sigaction");
+
+	file = argv[1];
+	ps = getpagesize();
+	if ((fd = open(file, O_RDWR)) == -1)
+		err(1, "open(%s)", file);
+	if ((error = fstat(fd, &st)) == -1)
+		err(1, "stat(%s)", file);
+	len = round_page(st.st_size);
+	if ((p = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED)
+			err(1, "mmap");
+	rlim.rlim_cur = rlim.rlim_max = len / 2;;
+	if (setrlimit(RLIMIT_FSIZE, &rlim) == -1)
+		err(1, "setrlimit(%ld)", len / 2);
+
+	p[len / 2 + ps] = 'a';
+
+	if (munmap(p, len) == -1)
+		err(1, "unmap()");
+	close(fd);
+
+}
+EOF
+here=`pwd`
+cd /tmp
+mycc -o setrlimit2 -Wall -Wextra -O0 -g setrlimit2.c || exit 1
+data=/tmp/setrlimit2.data
+dd if=/dev/zero of=$data bs=1m count=1 status=none
+h1=`md5 < $data`
+
+./setrlimit2 $data
+
+h2=`md5 < $data`
+rm -f /tmp/setrlimit2 /tmp/setrlimit2.c
+[ $h1 = $h2 ] && exit 1 || exit 0
diff --git a/tools/test/stress2/misc/sigreturn3.sh b/tools/test/stress2/misc/sigreturn3.sh
new file mode 100755
index 000000000000..1070876539b6
--- /dev/null
+++ b/tools/test/stress2/misc/sigreturn3.sh
@@ -0,0 +1,182 @@
+#!/bin/sh
+
+#
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# 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 <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;
+	int i;
+
+	start = time(NULL);
+	for (i = 0; time(NULL) - start < 10; i++) {
+		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) ||
+		    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
+	date +%T
+done
+rm -f /tmp/$prog /tmp/$ptog.c /tmp/$prog.core
+exit 0
diff --git a/tools/test/stress2/misc/sigreturn4.sh b/tools/test/stress2/misc/sigreturn4.sh
new file mode 100755
index 000000000000..f7916dc3b1ee
--- /dev/null
+++ b/tools/test/stress2/misc/sigreturn4.sh
@@ -0,0 +1,208 @@
+#!/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 i, n;
+
+	start = time(NULL);
+	for (i = 0; time(NULL) - start < 10; i++) {
+		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) ||
+		    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
+	date +%T
+done
+rm -f /tmp/$prog /tmp/$ptog.c /tmp/$prog.core
+exit 0