kprobes: add testcases for s390

Add a few testcases to make sure that it's not possible to place
a kprobe in the mid of an instruction on s390.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 75 insertions, 0 deletions

diff --git a/arch/s390/lib/test_kprobes.c b/arch/s390/lib/test_kprobes.c
new file mode 100644
index 000000000000..9e62d62812e5
--- /dev/null
+++ b/arch/s390/lib/test_kprobes.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/kernel.h>
+#include <linux/kprobes.h>
+#include <linux/random.h>
+#include <kunit/test.h>
+#include "test_kprobes.h"
+
+static struct kprobe kp;
+
+static void setup_kprobe(struct kunit *test, struct kprobe *kp,
+			 const char *symbol, int offset)
+{
+	kp->offset = offset;
+	kp->addr = NULL;
+	kp->symbol_name = symbol;
+}
+
+static void test_kprobe_offset(struct kunit *test, struct kprobe *kp,
+			       const char *target, int offset)
+{
+	int ret;
+
+	setup_kprobe(test, kp, target, 0);
+	ret = register_kprobe(kp);
+	if (!ret)
+		unregister_kprobe(kp);
+	KUNIT_EXPECT_EQ(test, 0, ret);
+	setup_kprobe(test, kp, target, offset);
+	ret = register_kprobe(kp);
+	KUNIT_EXPECT_EQ(test, -EINVAL, ret);
+	if (!ret)
+		unregister_kprobe(kp);
+}
+
+static void test_kprobe_odd(struct kunit *test)
+{
+	test_kprobe_offset(test, &kp, "kprobes_target_odd",
+			   kprobes_target_odd_offs);
+}
+
+static void test_kprobe_in_insn4(struct kunit *test)
+{
+	test_kprobe_offset(test, &kp, "kprobes_target_in_insn4",
+			   kprobes_target_in_insn4_offs);
+}
+
+static void test_kprobe_in_insn6_lo(struct kunit *test)
+{
+	test_kprobe_offset(test, &kp, "kprobes_target_in_insn6_lo",
+			   kprobes_target_in_insn6_lo_offs);
+}
+
+static void test_kprobe_in_insn6_hi(struct kunit *test)
+{
+	test_kprobe_offset(test, &kp, "kprobes_target_in_insn6_hi",
+			   kprobes_target_in_insn6_hi_offs);
+}
+
+static struct kunit_case kprobes_testcases[] = {
+	KUNIT_CASE(test_kprobe_odd),
+	KUNIT_CASE(test_kprobe_in_insn4),
+	KUNIT_CASE(test_kprobe_in_insn6_lo),
+	KUNIT_CASE(test_kprobe_in_insn6_hi),
+	{}
+};
+
+static struct kunit_suite kprobes_test_suite = {
+	.name = "kprobes_test_s390",
+	.test_cases = kprobes_testcases,
+};
+
+kunit_test_suites(&kprobes_test_suite);
+
+MODULE_LICENSE("GPL");