1 files changed, 114 insertions, 0 deletions
diff --git a/lib/libc/tests/sys/mlock_helper.c b/lib/libc/tests/sys/mlock_helper.c
new file mode 100644
index 0000000..7fa40d1
--- /dev/null
+++ b/lib/libc/tests/sys/mlock_helper.c
@@ -0,0 +1,114 @@
+/*-
+ * Copyright (C) 2016 Bryan Drewery <bdrewery@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.
+ */
+
+/*
+ * Helper for mlock(3) to avoid EAGAIN errors
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+#include <atf-c.h>
+#include <errno.h>
+#include <stdio.h>
+#include <limits.h>
+
+#define	VM_MAX_WIRED "vm.max_wired"
+
+static void
+vm_max_wired_sysctl(int *old_value, int *new_value)
+{
+	size_t old_len;
+	size_t new_len = (new_value == NULL ? 0 : sizeof(int));
+
+	if (old_value == NULL)
+		printf("Setting the new value to %d\n", *new_value);
+	else {
+		ATF_REQUIRE_MSG(sysctlbyname(VM_MAX_WIRED, NULL, &old_len,
+		    new_value, new_len) == 0,
+		    "sysctlbyname(%s) failed: %s", VM_MAX_WIRED, strerror(errno));
+	}
+
+	ATF_REQUIRE_MSG(sysctlbyname(VM_MAX_WIRED, old_value, &old_len,
+	    new_value, new_len) == 0,
+	    "sysctlbyname(%s) failed: %s", VM_MAX_WIRED, strerror(errno));
+
+	if (old_value != NULL)
+		printf("Saved the old value (%d)\n", *old_value);
+}
+
+void
+set_vm_max_wired(int new_value)
+{
+	FILE *fp;
+	int old_value;
+
+	fp = fopen(VM_MAX_WIRED, "w");
+	if (fp == NULL) {
+		atf_tc_skip("could not open %s for writing: %s",
+		    VM_MAX_WIRED, strerror(errno));
+		return;
+	}
+
+	vm_max_wired_sysctl(&old_value, NULL);
+
+	ATF_REQUIRE_MSG(fprintf(fp, "%d", old_value) > 0,
+	    "saving %s failed", VM_MAX_WIRED);
+
+	fclose(fp);
+
+	vm_max_wired_sysctl(NULL, &new_value);
+}
+
+void
+restore_vm_max_wired(void)
+{
+	FILE *fp;
+	int saved_max_wired;
+
+	fp = fopen(VM_MAX_WIRED, "r");
+	if (fp == NULL) {
+		perror("fopen failed\n");
+		return;
+	}
+
+	if (fscanf(fp, "%d", &saved_max_wired) != 1) {
+		perror("fscanf failed\n");
+		fclose(fp);
+		return;
+	}
+
+	fclose(fp);
+	printf("old value in %s: %d\n", VM_MAX_WIRED, saved_max_wired);
+
+	if (saved_max_wired == 0) /* This will cripple the test host */
+		return;
+
+	vm_max_wired_sysctl(NULL, &saved_max_wired);
+}