[linux.git] / lib / test_fprobe.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * test_fprobe.c - simple sanity test for fprobe
 */

#include <linux/kernel.h>
#include <linux/fprobe.h>
#include <linux/random.h>
#include <kunit/test.h>

#define div_factor 3

static struct kunit *current_test;

static u32 rand1, entry_val, exit_val;

/* Use indirect calls to avoid inlining the target functions */
static u32 (*target)(u32 value);
static u32 (*target2)(u32 value);
static u32 (*target_nest)(u32 value, u32 (*nest)(u32));
static unsigned long target_ip;
static unsigned long target2_ip;
static unsigned long target_nest_ip;
static int entry_return_value;

static noinline u32 fprobe_selftest_target(u32 value)
{
	return (value / div_factor);
}

static noinline u32 fprobe_selftest_target2(u32 value)
{
	return (value / div_factor) + 1;
}

static noinline u32 fprobe_selftest_nest_target(u32 value, u32 (*nest)(u32))
{
	return nest(value + 2);
}

static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip,
				    unsigned long ret_ip,
				    struct pt_regs *regs, void *data)
{
	KUNIT_EXPECT_FALSE(current_test, preemptible());
	/* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
	if (ip != target_ip)
		KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
	entry_val = (rand1 / div_factor);
	if (fp->entry_data_size) {
		KUNIT_EXPECT_NOT_NULL(current_test, data);
		if (data)
			*(u32 *)data = entry_val;
	} else
		KUNIT_EXPECT_NULL(current_test, data);

	return entry_return_value;
}

static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
				    unsigned long ret_ip,
				    struct pt_regs *regs, void *data)
{
	unsigned long ret = regs_return_value(regs);

	KUNIT_EXPECT_FALSE(current_test, preemptible());
	if (ip != target_ip) {
		KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
		KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
	} else
		KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
	KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor));
	exit_val = entry_val + div_factor;
	if (fp->entry_data_size) {
		KUNIT_EXPECT_NOT_NULL(current_test, data);
		if (data)
			KUNIT_EXPECT_EQ(current_test, *(u32 *)data, entry_val);
	} else
		KUNIT_EXPECT_NULL(current_test, data);
}

static notrace int nest_entry_handler(struct fprobe *fp, unsigned long ip,
				      unsigned long ret_ip,
				      struct pt_regs *regs, void *data)
{
	KUNIT_EXPECT_FALSE(current_test, preemptible());
	return 0;
}

static notrace void nest_exit_handler(struct fprobe *fp, unsigned long ip,
				      unsigned long ret_ip,
				      struct pt_regs *regs, void *data)
{
	KUNIT_EXPECT_FALSE(current_test, preemptible());
	KUNIT_EXPECT_EQ(current_test, ip, target_nest_ip);
}

/* Test entry only (no rethook) */
static void test_fprobe_entry(struct kunit *test)
{
	struct fprobe fp_entry = {
		.entry_handler = fp_entry_handler,
	};

	current_test = test;

	/* Before register, unregister should be failed. */
	KUNIT_EXPECT_NE(test, 0, unregister_fprobe(&fp_entry));
	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp_entry, "fprobe_selftest_target*", NULL));

	entry_val = 0;
	exit_val = 0;
	target(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, 0, exit_val);

	entry_val = 0;
	exit_val = 0;
	target2(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, 0, exit_val);

	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp_entry));
}

static void test_fprobe(struct kunit *test)
{
	struct fprobe fp = {
		.entry_handler = fp_entry_handler,
		.exit_handler = fp_exit_handler,
	};

	current_test = test;
	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target*", NULL));

	entry_val = 0;
	exit_val = 0;
	target(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);

	entry_val = 0;
	exit_val = 0;
	target2(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);

	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}

static void test_fprobe_syms(struct kunit *test)
{
	static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_target2"};
	struct fprobe fp = {
		.entry_handler = fp_entry_handler,
		.exit_handler = fp_exit_handler,
	};

	current_test = test;
	KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));

	entry_val = 0;
	exit_val = 0;
	target(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);

	entry_val = 0;
	exit_val = 0;
	target2(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);

	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}

/* Test private entry_data */
static void test_fprobe_data(struct kunit *test)
{
	struct fprobe fp = {
		.entry_handler = fp_entry_handler,
		.exit_handler = fp_exit_handler,
		.entry_data_size = sizeof(u32),
	};

	current_test = test;
	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));

	target(rand1);

	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}

/* Test nr_maxactive */
static void test_fprobe_nest(struct kunit *test)
{
	static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_nest_target"};
	struct fprobe fp = {
		.entry_handler = nest_entry_handler,
		.exit_handler = nest_exit_handler,
		.nr_maxactive = 1,
	};

	current_test = test;
	KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));

	target_nest(rand1, target);
	KUNIT_EXPECT_EQ(test, 1, fp.nmissed);

	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}

static void test_fprobe_skip(struct kunit *test)
{
	struct fprobe fp = {
		.entry_handler = fp_entry_handler,
		.exit_handler = fp_exit_handler,
	};

	current_test = test;
	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));

	entry_return_value = 1;
	entry_val = 0;
	exit_val = 0;
	target(rand1);
	KUNIT_EXPECT_NE(test, 0, entry_val);
	KUNIT_EXPECT_EQ(test, 0, exit_val);
	KUNIT_EXPECT_EQ(test, 0, fp.nmissed);
	entry_return_value = 0;

	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
}

static unsigned long get_ftrace_location(void *func)
{
	unsigned long size, addr = (unsigned long)func;

	if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size)
		return 0;

	return ftrace_location_range(addr, addr + size - 1);
}

static int fprobe_test_init(struct kunit *test)
{
	rand1 = get_random_u32_above(div_factor);
	target = fprobe_selftest_target;
	target2 = fprobe_selftest_target2;
	target_nest = fprobe_selftest_nest_target;
	target_ip = get_ftrace_location(target);
	target2_ip = get_ftrace_location(target2);
	target_nest_ip = get_ftrace_location(target_nest);

	return 0;
}

static struct kunit_case fprobe_testcases[] = {
	KUNIT_CASE(test_fprobe_entry),
	KUNIT_CASE(test_fprobe),
	KUNIT_CASE(test_fprobe_syms),
	KUNIT_CASE(test_fprobe_data),
	KUNIT_CASE(test_fprobe_nest),
	KUNIT_CASE(test_fprobe_skip),
	{}
};

static struct kunit_suite fprobe_test_suite = {
	.name = "fprobe_test",
	.init = fprobe_test_init,
	.test_cases = fprobe_testcases,
};

kunit_test_suites(&fprobe_test_suite);
Commit	Line	Data
f4616fab MH	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* test_fprobe.c - simple sanity test for fprobe
	4	*/
	5
	6	#include <linux/kernel.h>
	7	#include <linux/fprobe.h>
	8	#include <linux/random.h>
	9	#include <kunit/test.h>
	10
	11	#define div_factor 3
	12
	13	static struct kunit *current_test;
	14
	15	static u32 rand1, entry_val, exit_val;
	16
	17	/* Use indirect calls to avoid inlining the target functions */
	18	static u32 (*target)(u32 value);
	19	static u32 (*target2)(u32 value);
7e7ef1bf	20	static u32 (target_nest)(u32 value, u32 (nest)(u32));
f4616fab MH	21	static unsigned long target_ip;
f4616fab MH	22	static unsigned long target2_ip;
7e7ef1bf	23	static unsigned long target_nest_ip;
87de2163	24	static int entry_return_value;
f4616fab MH	25
	26	static noinline u32 fprobe_selftest_target(u32 value)
	27	{
	28	return (value / div_factor);
	29	}
	30
	31	static noinline u32 fprobe_selftest_target2(u32 value)
	32	{
	33	return (value / div_factor) + 1;
	34	}
	35
7e7ef1bf MHG	36	static noinline u32 fprobe_selftest_nest_target(u32 value, u32 (*nest)(u32))
	37	{
	38	return nest(value + 2);
	39	}
	40
39d95420	41	static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip,
cb16330d MHG	42	unsigned long ret_ip,
cb16330d MHG	43	struct pt_regs regs, void data)
f4616fab MH	44	{
	45	KUNIT_EXPECT_FALSE(current_test, preemptible());
	46	/* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
	47	if (ip != target_ip)
	48	KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
	49	entry_val = (rand1 / div_factor);
34cabf8f MHG	50	if (fp->entry_data_size) {
	51	KUNIT_EXPECT_NOT_NULL(current_test, data);
	52	if (data)
	53	(u32 )data = entry_val;
	54	} else
	55	KUNIT_EXPECT_NULL(current_test, data);
39d95420	56
87de2163	57	return entry_return_value;
f4616fab MH	58	}
f4616fab MH	59
76d0de57	60	static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
cb16330d	61	unsigned long ret_ip,
76d0de57	62	struct pt_regs regs, void data)
f4616fab MH	63	{
	64	unsigned long ret = regs_return_value(regs);
	65
	66	KUNIT_EXPECT_FALSE(current_test, preemptible());
	67	if (ip != target_ip) {
	68	KUNIT_EXPECT_EQ(current_test, ip, target2_ip);
	69	KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1);
	70	} else
	71	KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
	72	KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor));
	73	exit_val = entry_val + div_factor;
34cabf8f MHG	74	if (fp->entry_data_size) {
	75	KUNIT_EXPECT_NOT_NULL(current_test, data);
	76	if (data)
	77	KUNIT_EXPECT_EQ(current_test, (u32 )data, entry_val);
	78	} else
	79	KUNIT_EXPECT_NULL(current_test, data);
f4616fab MH	80	}
f4616fab MH	81
39d95420	82	static notrace int nest_entry_handler(struct fprobe *fp, unsigned long ip,
cb16330d MHG	83	unsigned long ret_ip,
cb16330d MHG	84	struct pt_regs regs, void data)
7e7ef1bf MHG	85	{
7e7ef1bf MHG	86	KUNIT_EXPECT_FALSE(current_test, preemptible());
39d95420	87	return 0;
7e7ef1bf MHG	88	}
	89
	90	static notrace void nest_exit_handler(struct fprobe *fp, unsigned long ip,
cb16330d MHG	91	unsigned long ret_ip,
cb16330d MHG	92	struct pt_regs regs, void data)
7e7ef1bf MHG	93	{
	94	KUNIT_EXPECT_FALSE(current_test, preemptible());
	95	KUNIT_EXPECT_EQ(current_test, ip, target_nest_ip);
f4616fab MH	96	}
	97
	98	/* Test entry only (no rethook) */
	99	static void test_fprobe_entry(struct kunit *test)
	100	{
	101	struct fprobe fp_entry = {
	102	.entry_handler = fp_entry_handler,
	103	};
	104
	105	current_test = test;
	106
	107	/* Before register, unregister should be failed. */
	108	KUNIT_EXPECT_NE(test, 0, unregister_fprobe(&fp_entry));
	109	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp_entry, "fprobe_selftest_target*", NULL));
	110
	111	entry_val = 0;
	112	exit_val = 0;
	113	target(rand1);
	114	KUNIT_EXPECT_NE(test, 0, entry_val);
	115	KUNIT_EXPECT_EQ(test, 0, exit_val);
	116
	117	entry_val = 0;
	118	exit_val = 0;
	119	target2(rand1);
	120	KUNIT_EXPECT_NE(test, 0, entry_val);
	121	KUNIT_EXPECT_EQ(test, 0, exit_val);
	122
	123	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp_entry));
	124	}
	125
	126	static void test_fprobe(struct kunit *test)
	127	{
	128	struct fprobe fp = {
	129	.entry_handler = fp_entry_handler,
	130	.exit_handler = fp_exit_handler,
	131	};
	132
	133	current_test = test;
	134	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target*", NULL));
	135
	136	entry_val = 0;
	137	exit_val = 0;
	138	target(rand1);
	139	KUNIT_EXPECT_NE(test, 0, entry_val);
	140	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
	141
	142	entry_val = 0;
	143	exit_val = 0;
	144	target2(rand1);
	145	KUNIT_EXPECT_NE(test, 0, entry_val);
	146	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
	147
	148	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
	149	}
	150
	151	static void test_fprobe_syms(struct kunit *test)
	152	{
	153	static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_target2"};
	154	struct fprobe fp = {
	155	.entry_handler = fp_entry_handler,
	156	.exit_handler = fp_exit_handler,
	157	};
	158
	159	current_test = test;
160	KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
161
162	entry_val = 0;
163	exit_val = 0;
164	target(rand1);
165	KUNIT_EXPECT_NE(test, 0, entry_val);
166	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
167
168	entry_val = 0;
169	exit_val = 0;
170	target2(rand1);
171	KUNIT_EXPECT_NE(test, 0, entry_val);
172	KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val);
173
174	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
175	}
176
34cabf8f MHG	177	/* Test private entry_data */
	178	static void test_fprobe_data(struct kunit *test)
	179	{
	180	struct fprobe fp = {
	181	.entry_handler = fp_entry_handler,
	182	.exit_handler = fp_exit_handler,
	183	.entry_data_size = sizeof(u32),
	184	};
	185
	186	current_test = test;
	187	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
	188
	189	target(rand1);
	190
	191	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
	192	}
	193
7e7ef1bf MHG	194	/* Test nr_maxactive */
	195	static void test_fprobe_nest(struct kunit *test)
	196	{
	197	static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_nest_target"};
	198	struct fprobe fp = {
	199	.entry_handler = nest_entry_handler,
	200	.exit_handler = nest_exit_handler,
	201	.nr_maxactive = 1,
	202	};
	203
	204	current_test = test;
	205	KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2));
	206
	207	target_nest(rand1, target);
	208	KUNIT_EXPECT_EQ(test, 1, fp.nmissed);
	209
	210	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
	211	}
	212
87de2163 MHG	213	static void test_fprobe_skip(struct kunit *test)
	214	{
	215	struct fprobe fp = {
	216	.entry_handler = fp_entry_handler,
	217	.exit_handler = fp_exit_handler,
	218	};
	219
	220	current_test = test;
	221	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target", NULL));
	222
	223	entry_return_value = 1;
	224	entry_val = 0;
	225	exit_val = 0;
	226	target(rand1);
	227	KUNIT_EXPECT_NE(test, 0, entry_val);
	228	KUNIT_EXPECT_EQ(test, 0, exit_val);
	229	KUNIT_EXPECT_EQ(test, 0, fp.nmissed);
	230	entry_return_value = 0;
	231
	232	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
	233	}
	234
f4616fab MH	235	static unsigned long get_ftrace_location(void *func)
	236	{
	237	unsigned long size, addr = (unsigned long)func;
	238
	239	if (!kallsyms_lookup_size_offset(addr, &size, NULL) \|\| !size)
	240	return 0;
	241
	242	return ftrace_location_range(addr, addr + size - 1);
	243	}
	244
	245	static int fprobe_test_init(struct kunit *test)
	246	{
d247aabd	247	rand1 = get_random_u32_above(div_factor);
f4616fab MH	248	target = fprobe_selftest_target;
f4616fab MH	249	target2 = fprobe_selftest_target2;
7e7ef1bf	250	target_nest = fprobe_selftest_nest_target;
f4616fab MH	251	target_ip = get_ftrace_location(target);
f4616fab MH	252	target2_ip = get_ftrace_location(target2);
7e7ef1bf	253	target_nest_ip = get_ftrace_location(target_nest);
f4616fab MH	254
	255	return 0;
	256	}
	257
	258	static struct kunit_case fprobe_testcases[] = {
	259	KUNIT_CASE(test_fprobe_entry),
	260	KUNIT_CASE(test_fprobe),
	261	KUNIT_CASE(test_fprobe_syms),
34cabf8f	262	KUNIT_CASE(test_fprobe_data),
7e7ef1bf	263	KUNIT_CASE(test_fprobe_nest),
87de2163	264	KUNIT_CASE(test_fprobe_skip),
f4616fab MH	265	{}
	266	};
	267
	268	static struct kunit_suite fprobe_test_suite = {
	269	.name = "fprobe_test",
	270	.init = fprobe_test_init,
	271	.test_cases = fprobe_testcases,
	272	};
	273
	274	kunit_test_suites(&fprobe_test_suite);
	275