--- /dev/null
+# $OpenBSD: Makefile,v 1.1 2021/04/28 17:59:53 bluhm Exp $
+
+# Copyright (c) 2021 Alexander Bluhm <bluhm@openbsd.org>
+#
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+# To hunt kernel bugs during exit, terminate processes simultaneously.
+# Fork 300 children that sleep. Kill them together as process group.
+# Sleeping can optionally be done with individual memory layout by
+# executing sleep(1).
+
+PROG= fork-exit
+WARNINGS= yes
+
+REGRESS_TARGETS += run-fork1-exit
+run-fork1-exit:
+ # test forking a single child
+ ./fork-exit
+
+REGRESS_TARGETS += run-fork-exit
+run-fork-exit:
+ # fork 300 children and kill them simultaneously as process group
+ ulimit -p 500 -n 1000; ./fork-exit -p 300
+
+REGRESS_TARGETS += run-fork-exec-exit
+run-fork-exec-exit:
+ # fork 300 children, exec sleep programs, and kill process group
+ ulimit -p 500 -n 1000; ./fork-exit -e -p 300
+
+.include <bsd.regress.mk>
--- /dev/null
+/* $OpenBSD: fork-exit.c,v 1.1 2021/04/28 17:59:53 bluhm Exp $ */
+
+/*
+ * Copyright (c) 2021 Alexander Bluhm <bluhm@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/select.h>
+#include <sys/wait.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int execute = 0;
+int daemonize = 0;
+int procs = 1;
+int timeout = 30;
+
+static void __dead
+usage(void)
+{
+ fprintf(stderr, "fork-exit [-ed] [-p procs] [-t timeout]\n"
+ " -e child execs sleep(1), default call sleep(3)\n"
+ " -d daemonize, if already process group leader\n"
+ " -p procs number of processes to fork, default 1\n"
+ " -t timeout parent and children will exit, default 30 sec\n");
+ exit(2);
+}
+
+static void __dead
+exec_sleep(void)
+{
+ execl("/bin/sleep", "sleep", "30", NULL);
+ err(1, "exec sleep");
+}
+
+static void
+fork_sleep(int fd)
+{
+ switch (fork()) {
+ case -1:
+ err(1, "fork");
+ case 0:
+ break;
+ default:
+ return;
+ }
+ /* close pipe to parent and sleep until killed */
+ if (execute) {
+ if (fcntl(fd, F_SETFD, FD_CLOEXEC))
+ err(1, "fcntl FD_CLOEXEC");
+ exec_sleep();
+ } else {
+ if (close(fd) == -1)
+ err(1, "close write");
+ if (sleep(timeout) != 0)
+ err(1, "sleep %d", timeout);
+ }
+ _exit(0);
+}
+
+static void
+sigexit(int sig)
+{
+ int i, status;
+ pid_t pid;
+
+ /* all children must terminate in time */
+ if ((int)alarm(timeout) == -1)
+ err(1, "alarm");
+
+ for (i = 0; i < procs; i++) {
+ pid = wait(&status);
+ if (pid == -1)
+ err(1, "wait");
+ if (!WIFSIGNALED(status))
+ errx(1, "child %d not killed", pid);
+ if(WTERMSIG(status) != SIGTERM)
+ errx(1, "child %d signal %d", pid, WTERMSIG(status));
+ }
+ exit(0);
+}
+
+int
+main(int argc, char *argv[])
+{
+ const char *errstr;
+ int ch, i, fdmax, fdlen, *rfds, waiting;
+ fd_set *fdset;
+ pid_t pgrp;
+ struct timeval tv;
+
+ while ((ch = getopt(argc, argv, "edp:t:")) != -1) {
+ switch (ch) {
+ case 'e':
+ execute = 1;
+ break;
+ case 'd':
+ daemonize = 1;
+ break;
+ case 'p':
+ procs = strtonum(optarg, 0, INT_MAX, &errstr);
+ if (errstr != NULL)
+ errx(1, "number of procs is %s: %s", errstr,
+ optarg);
+ break;
+ case 't':
+ timeout = strtonum(optarg, 0, INT_MAX, &errstr);
+ if (errstr != NULL)
+ errx(1, "timeout is %s: %s", errstr, optarg);
+ default:
+ usage();
+ }
+ }
+
+ /* become process group leader */
+ pgrp = setsid();
+ if (pgrp == -1) {
+ if (errno == EPERM && daemonize) {
+ /* get rid of leadership */
+ switch (fork()) {
+ case -1:
+ err(1, "fork parent");
+ case 0:
+ /* try again */
+ pgrp = setsid();
+ break;
+ default:
+ _exit(0);
+ }
+ }
+ if (!daemonize)
+ warnx("try -d to become process group leader");
+ if (pgrp == -1)
+ err(1, "setsid");
+ }
+
+ /* create pipes to keep in contact with children */
+ rfds = reallocarray(NULL, procs, sizeof(int));
+ if (rfds == NULL)
+ err(1, "rfds");
+ fdmax = 0;
+
+ /* fork child processes and pass writing end of pipe */
+ for (i = 0; i < procs; i++) {
+ int pipefds[2];
+
+ if (pipe(pipefds) == -1)
+ err(1, "pipe");
+ if (fdmax < pipefds[0])
+ fdmax = pipefds[0];
+ rfds[i] = pipefds[0];
+ fork_sleep(pipefds[1]);
+ if (close(pipefds[1]) == -1)
+ err(1, "close parent");
+ }
+
+ /* create select mask with all reading ends of child pipes */
+ fdlen = howmany(fdmax + 1, NFDBITS);
+ fdset = calloc(fdlen, sizeof(fd_mask));
+ if (fdset == NULL)
+ err(1, "fdset");
+ for (i = 0; i < procs; i++) {
+ FD_SET(rfds[i], fdset);
+ }
+
+ /* wait until all child processes are waiting */
+ do {
+ waiting = 0;
+ tv.tv_sec = timeout;
+ tv.tv_usec = 0;
+ errno = ETIMEDOUT;
+ if (select(fdmax + 1, fdset, NULL, NULL, &tv) <= 0)
+ err(1, "select");
+
+ /* remove fd of children that closed their end */
+ for (i = 0; i < procs; i++) {
+ if (rfds[i] >= 0) {
+ if (FD_ISSET(rfds[i], fdset)) {
+ if (close(rfds[i]) == -1)
+ err(1, "close read");
+ FD_CLR(rfds[i], fdset);
+ rfds[i] = -1;
+ } else {
+ FD_SET(rfds[i], fdset);
+ waiting = 1;
+ }
+ }
+ }
+ } while (waiting);
+
+ /* kill all children simultaneously, parent exits in signal handler */
+ if (signal(SIGTERM, sigexit) == SIG_ERR)
+ err(1, "signal SIGTERM");
+ if (kill(-pgrp, SIGTERM) == -1)
+ err(1, "kill %d", -pgrp);
+
+ errx(1, "alive");
+}
projects / openbsd / commitdiff