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-rw-r--r--bin/pkill/tests/spin_helper.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/bin/pkill/tests/spin_helper.c b/bin/pkill/tests/spin_helper.c
new file mode 100644
index 000000000000..10541ad12516
--- /dev/null
+++ b/bin/pkill/tests/spin_helper.c
@@ -0,0 +1,123 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Klara, Inc.
+ *
+ * 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.
+ */
+#include <sys/cdefs.h>
+
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+
+static int
+exec_shortargs(char *argv[])
+{
+ char *flag_arg = argv[2];
+ char *sentinel = argv[3];
+ char * nargv[] = { argv[0], __DECONST(char *, "--spin"), flag_arg,
+ sentinel, NULL };
+ char * const nenvp[] = { NULL };
+
+ execve(argv[0], nargv, nenvp);
+ err(1, "execve");
+}
+
+static int
+exec_largeargs(char *argv[])
+{
+ char *flag_arg = argv[2];
+ char *sentinel = argv[3];
+ /*
+ * Account for each argument and their NUL terminator, as well as an
+ * extra NUL terminator.
+ */
+ size_t bufsz = ARG_MAX -
+ ((strlen(argv[0]) + 1) + sizeof("--spin") + (strlen(flag_arg) + 1) +
+ (strlen(sentinel) + 1) + 1);
+ char *s = NULL;
+ char * nargv[] = { argv[0], __DECONST(char *, "--spin"), flag_arg, NULL,
+ sentinel, NULL };
+ char * const nenvp[] = { NULL };
+
+ /*
+ * Our heuristic may or may not be accurate, we'll keep trying with
+ * smaller argument sizes as needed until we stop getting E2BIG.
+ */
+ do {
+ if (s == NULL)
+ s = malloc(bufsz + 1);
+ else
+ s = realloc(s, bufsz + 1);
+ if (s == NULL)
+ abort();
+ memset(s, 'x', bufsz);
+ s[bufsz] = '\0';
+ nargv[3] = s;
+
+ execve(argv[0], nargv, nenvp);
+ bufsz--;
+ } while (errno == E2BIG);
+ err(1, "execve");
+}
+
+int
+main(int argc, char *argv[])
+{
+
+ if (argc > 1 && strcmp(argv[1], "--spin") == 0) {
+ int fd;
+
+ if (argc < 4) {
+ fprintf(stderr, "usage: %s --spin flagfile ...\n", argv[0]);
+ return (1);
+ }
+
+ fd = open(argv[2], O_RDWR | O_CREAT, 0755);
+ if (fd < 0)
+ err(1, "%s", argv[2]);
+ close(fd);
+
+ for (;;) {
+ sleep(1);
+ }
+
+ return (1);
+ }
+
+ if (argc != 4) {
+ fprintf(stderr, "usage: %s [--short | --long] flagfile sentinel\n",
+ argv[0]);
+ return (1);
+ }
+
+ if (strcmp(argv[1], "--short") == 0)
+ exec_shortargs(argv);
+ else
+ exec_largeargs(argv);
+}