1 files changed, 63 insertions, 0 deletions
diff --git a/lib/libc/tests/sys/swapcontext_test.c b/lib/libc/tests/sys/swapcontext_test.c
new file mode 100644
index 000000000000..f341a746e515
--- /dev/null
+++ b/lib/libc/tests/sys/swapcontext_test.c
@@ -0,0 +1,63 @@
+/*-
+ * Copyright (c) 2025 Raptor Computing Systems, LLC
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ucontext.h>
+#include <errno.h>
+
+#include <atf-c.h>
+
+#define STACK_SIZE	(64ull << 10)
+
+static volatile int callback_reached = 0;
+
+static ucontext_t uctx_save, uctx_switch;
+
+static void swapcontext_callback()
+{
+	// Increment callback reached variable
+	// If this is called multiple times, we will fail the test
+	// If this is not called at all, we will fail the test
+	callback_reached++;
+}
+
+ATF_TC(swapcontext_basic);
+ATF_TC_HEAD(swapcontext_basic, tc)
+{
+	atf_tc_set_md_var(tc, "descr",
+		"Verify basic functionality of swapcontext");
+}
+
+ATF_TC_BODY(swapcontext_basic, tc)
+{
+	char *stack;
+        int res;
+
+	stack = malloc(STACK_SIZE);
+	ATF_REQUIRE_MSG(stack != NULL, "malloc failed: %s", strerror(errno));
+	res = getcontext(&uctx_switch);
+	ATF_REQUIRE_MSG(res == 0, "getcontext failed: %s", strerror(errno));
+
+	uctx_switch.uc_stack.ss_sp = stack;
+	uctx_switch.uc_stack.ss_size = STACK_SIZE;
+	uctx_switch.uc_link = &uctx_save;
+	makecontext(&uctx_switch, swapcontext_callback, 0);
+
+	res = swapcontext(&uctx_save, &uctx_switch);
+
+        ATF_REQUIRE_MSG(res == 0, "swapcontext failed: %s", strerror(errno));
+        ATF_REQUIRE_MSG(callback_reached == 1,
+		"callback failed, reached %d times", callback_reached);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, swapcontext_basic);
+
+	return (atf_no_error());
+}
+