test code for kprobe

[Nam Cao <namcaov@gmail.com>]

---
 drivers/test_kprobe/Makefile      |   3 +
 drivers/test_kprobe/test_kprobe.c | 265 ++++++++++++++++++++++++++++++
 2 files changed, 268 insertions(+)
 create mode 100644 drivers/test_kprobe/Makefile
 create mode 100644 drivers/test_kprobe/test_kprobe.c

diff --git a/drivers/test_kprobe/Makefile b/drivers/test_kprobe/Makefile
new file mode 100644
index 000000000000..c3c39bd0f8b5
--- /dev/null
+++ b/drivers/test_kprobe/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+obj-m += test_kprobe.o
diff --git a/drivers/test_kprobe/test_kprobe.c b/drivers/test_kprobe/test_kprobe.c
new file mode 100644
index 000000000000..543108c5fc8a
--- /dev/null
+++ b/drivers/test_kprobe/test_kprobe.c
@@ -0,0 +1,265 @@
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kprobes.h>
+#include <linux/string.h>
+MODULE_LICENSE("Dual BSD/GPL");
+
+__attribute__ ((naked))
+int sample_c_j(void) {
+	__asm__(
+		"c.j label_cj\n"
+		"li a0, 0\n ret\n"
+		"li a0, 1\n ret\n"
+		"li a0, 2\n ret\n"
+		"li a0, 3\n ret\n"
+		"label_cj:\n"
+		"li a0, 4\n ret\n"
+		"li a0, 5\n ret\n"
+		"li a0, 6\n ret\n"
+	);
+}
+
+__attribute__ ((naked))
+int sample_c_jr(void) {
+	__asm__(
+		"la a0, label_c_jr\n"
+		"c_jr_location:\n"
+		"c.jr a0\n"
+		"li a0, 0\n ret\n"
+		"li a0, 1\n ret\n"
+		"li a0, 2\n ret\n"
+		"li a0, 3\n ret\n"
+		"label_c_jr:\n"
+		"li a0, 4\n ret\n"
+		"li a0, 5\n ret\n"
+		"li a0, 6\n ret\n"
+	);
+}
+
+__attribute__ ((naked))
+int sample_c_jalr(void) {
+	__asm__(
+		"mv a1, x1\n"
+		"la a0, label_c_jalr\n"
+		"c_jalr_location:\n"
+		"c.jalr a0\n"
+
+		"addi a0, a0, -5\n"
+		"jr a1\n"
+
+		"label_c_jalr:\n"
+		"li a0, 9\n ret\n"
+	);
+}
+
+__attribute__ ((naked))
+int sample_c_beqz(int a0) {
+	__asm__(
+		"c.beqz a0, beqz_label\n"
+		"li a0, 10\n ret\n"
+		"beqz_label:\n"
+		"li a0, 4\n ret\n"
+	);
+}
+
+__attribute__ ((naked))
+int sample_c_bnez(int a0) {
+	__asm__(
+		"c.bnez a0, bnez_label\n"
+		"li a0, 10\n ret\n"
+		"bnez_label:\n"
+		"li a0, 4\n ret\n"
+	);
+}
+
+static int pre_handler(struct kprobe *p, struct pt_regs *regs) {
+	printk("pre_handler() called\n");
+
+	return 0;
+}
+
+static int test_c_j(void) {
+	static struct kprobe kp;
+
+	int ret;
+
+	/* Test C.J */
+	kp.symbol_name = "sample_c_j";
+	kp.pre_handler = pre_handler;
+
+	ret = register_kprobe(&kp);
+	if (ret) {
+		printk("Couldn't register kprobe, err=%d\n", ret);
+		return -1;
+	}
+
+	ret = sample_c_j();
+	if (ret != 4) {
+		printk("ERROR: expect value 4, got %d\n", ret);
+		return -1;
+	}
+	else {
+		printk("Got value 4, all good!\n");
+		return 0;
+	}
+}
+
+static int test_c_jr(void) {
+	static struct kprobe kp;
+	int ret;
+
+	/* Test C.JR */
+	kp.symbol_name = "c_jr_location";
+	kp.pre_handler = pre_handler;
+
+	ret = register_kprobe(&kp);
+	if (ret) {
+		printk("Couldn't register kprobe, err=%d\n", ret);
+		return -1;
+	}
+
+	ret = sample_c_jr();
+	if (ret != 4) {
+		printk("Expect value 4, got %d\n", ret);
+		return -1;
+	}
+	else {
+		printk("Got value 4, all good!\n");
+		return 0;
+	}
+}
+
+static int test_c_jalr(void) {
+	struct kprobe kp;
+	int ret;
+
+	memset(&kp, 0, sizeof(kp));
+
+	/* Test C.JR */
+	kp.symbol_name = "c_jalr_location";
+	kp.pre_handler = pre_handler;
+
+	ret = register_kprobe(&kp);
+	if (ret) {
+		printk("Couldn't register kprobe, err=%d\n", ret);
+		return -1;
+	}
+
+	ret = sample_c_jalr();
+	if (ret != 4) {
+		printk("Expect value 4, got %d\n", ret);
+		return -1;
+	}
+	else {
+		printk("Got value 4, all good!\n");
+	}
+
+	unregister_kprobe(&kp);
+
+	return 0;
+}
+
+static int test_c_bnez(void) {
+	static struct kprobe kp;
+
+	int ret;
+
+	/* Test C.JR */
+	kp.symbol_name = "sample_c_bnez";
+	kp.pre_handler = pre_handler;
+
+	ret = register_kprobe(&kp);
+	if (ret) {
+		printk("Couldn't register kprobe, err=%d\n", ret);
+		return -1;
+	}
+
+	ret = sample_c_bnez(1);
+	if (ret != 4) {
+		printk("Expect value 4, got %d\n", ret);
+		return -1;
+	} else {
+		printk("Got value 4, all good!\n");
+	}
+
+	ret = sample_c_bnez(0);
+	if (ret != 10) {
+		printk("Expect value 10, got %d\n", ret);
+		return -1;
+	} else {
+		printk("Got value 4, all good!\n");
+	}
+
+	return 0;
+}
+
+static int test_c_beqz(void) {
+	static struct kprobe kp;
+
+	int ret;
+
+	/* Test C.JR */
+	kp.symbol_name = "sample_c_beqz";
+	kp.pre_handler = pre_handler;
+
+	ret = register_kprobe(&kp);
+	if (ret) {
+		printk("Couldn't register kprobe, err=%d\n", ret);
+		return -1;
+	}
+
+	ret = sample_c_beqz(0);
+	if (ret != 4) {
+		printk("Expect value 4, got %d\n", ret);
+		return -1;
+	}
+	else {
+		printk("Got value 4, all good!\n");
+		return 0;
+	}
+
+	ret = sample_c_beqz(1);
+	if (ret != 10) {
+		printk("Expect value 10, got %d\n", ret);
+		return -1;
+	}
+	else {
+		printk("Got value 4, all good!\n");
+		return 0;
+	}
+}
+
+static int hello_init(void)
+{
+	printk("Hello\n");
+
+	printk("Testing C.J...\n");
+	if (test_c_j())
+		return -1;
+
+	printk("Testing C.JR...\n");
+	if (test_c_jr())
+		return -1;
+
+	printk("Testing C.JALR...\n");
+	if (test_c_jalr())
+		return -1;
+
+	printk("Testing C.BNEZ...\n");
+	if (test_c_bnez())
+		return -1;
+
+	printk("Testing C.BEQZ...\n");
+	if (test_c_beqz())
+		return -1;
+
+	return 0;
+}
+
+static void hello_exit(void)
+{
+	printk("Goodbye\n");
+}
+
+module_init(hello_init);
+module_exit(hello_exit);
-- 
2.34.1