4 # SPDX-License-Identifier: BSD-2-Clause-FreeBSD
6 # Copyright (c) 2021 Mark Johnston <markj@freebsd.org>
8 # Redistribution and use in source and binary forms, with or without
9 # modification, are permitted provided that the following conditions
11 # 1. Redistributions of source code must retain the above copyright
12 # notice, this list of conditions and the following disclaimer.
13 # 2. Redistributions in binary form must reproduce the above copyright
14 # notice, this list of conditions and the following disclaimer in the
15 # documentation and/or other materials provided with the distribution.
17 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 # 'panic: vm_fault_hold: fault on nofault entry, addr: 0x33522000' seen.
33 cat > /tmp/midi.c <<EOF
37 #include <stdatomic.h>
43 static _Atomic(int) threads;
47 t(void *data __unused)
53 (void)atomic_fetch_add(&threads, 1);
54 while (atomic_load(&threads) != NTHREADS)
58 arc4random_buf(&off, sizeof(off));
59 if ((n = pread(fd, buf, sizeof(buf), off)) >= 0)
60 write(STDOUT_FILENO, buf, n);
69 pthread_t tid[NTHREADS];
72 fd = open("/dev/midistat", O_RDONLY);
76 for (i = 0; i < NTHREADS; i++)
77 if ((error = pthread_create(&tid[i], NULL, t, NULL)) != 0)
78 errc(1, error, "pthread_create");
79 for (i = 0; i < NTHREADS; i++)
80 if ((error = pthread_join(tid[i], NULL)) != 0)
81 errc(1, error, "pthread_join");
86 cc -o /tmp/midi -Wall -Wextra -O2 /tmp/midi.c -lpthread
89 while [ $((`date +%s` - start)) -lt 120 ]; do
90 timeout 10 /tmp/midi | strings | head -20
93 rm -f /tmp/midi /tmp/midi.c /tmp/midi.core