[linux-2.6-block.git] / kernel / kallsyms_selftest.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Test the function and performance of kallsyms
 *
 * Copyright (C) Huawei Technologies Co., Ltd., 2022
 *
 * Authors: Zhen Lei <thunder.leizhen@huawei.com> Huawei
 */

#define pr_fmt(fmt) "kallsyms_selftest: " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/random.h>
#include <linux/sched/clock.h>
#include <linux/kthread.h>
#include <linux/vmalloc.h>

#include "kallsyms_internal.h"
#include "kallsyms_selftest.h"


#define MAX_NUM_OF_RECORDS		64

struct test_stat {
	int min;
	int max;
	int save_cnt;
	int real_cnt;
	int perf;
	u64 sum;
	char *name;
	unsigned long addr;
	unsigned long addrs[MAX_NUM_OF_RECORDS];
};

struct test_item {
	char *name;
	unsigned long addr;
};

#define ITEM_FUNC(s)				\
	{					\
		.name = #s,			\
		.addr = (unsigned long)s,	\
	}

#define ITEM_DATA(s)				\
	{					\
		.name = #s,			\
		.addr = (unsigned long)&s,	\
	}


static int kallsyms_test_var_bss_static;
static int kallsyms_test_var_data_static = 1;
int kallsyms_test_var_bss;
int kallsyms_test_var_data = 1;

static int kallsyms_test_func_static(void)
{
	kallsyms_test_var_bss_static++;
	kallsyms_test_var_data_static++;

	return 0;
}

int kallsyms_test_func(void)
{
	return kallsyms_test_func_static();
}

__weak int kallsyms_test_func_weak(void)
{
	kallsyms_test_var_bss++;
	kallsyms_test_var_data++;
	return 0;
}

static struct test_item test_items[] = {
	ITEM_FUNC(kallsyms_test_func_static),
	ITEM_FUNC(kallsyms_test_func),
	ITEM_FUNC(kallsyms_test_func_weak),
	ITEM_FUNC(vmalloc),
	ITEM_FUNC(vfree),
#ifdef CONFIG_KALLSYMS_ALL
	ITEM_DATA(kallsyms_test_var_bss_static),
	ITEM_DATA(kallsyms_test_var_data_static),
	ITEM_DATA(kallsyms_test_var_bss),
	ITEM_DATA(kallsyms_test_var_data),
	ITEM_DATA(vmap_area_list),
#endif
};

static char stub_name[KSYM_NAME_LEN];

static int stat_symbol_len(void *data, const char *name, struct module *mod, unsigned long addr)
{
	*(u32 *)data += strlen(name);

	return 0;
}

static void test_kallsyms_compression_ratio(void)
{
	u32 pos, off, len, num;
	u32 ratio, total_size, total_len = 0;

	kallsyms_on_each_symbol(stat_symbol_len, &total_len);

	/*
	 * A symbol name cannot start with a number. This stub name helps us
	 * traverse the entire symbol table without finding a match. It's used
	 * for subsequent performance tests, and its length is the average
	 * length of all symbol names.
	 */
	memset(stub_name, '4', sizeof(stub_name));
	pos = total_len / kallsyms_num_syms;
	stub_name[pos] = 0;

	pos = 0;
	num = 0;
	off = 0;
	while (pos < kallsyms_num_syms) {
		len = kallsyms_names[off];
		num++;
		off++;
		pos++;
		if ((len & 0x80) != 0) {
			len = (len & 0x7f) | (kallsyms_names[off] << 7);
			num++;
			off++;
		}
		off += len;
	}

	/*
	 * 1. The length fields is not counted
	 * 2. The memory occupied by array kallsyms_token_table[] and
	 *    kallsyms_token_index[] needs to be counted.
	 */
	total_size = off - num;
	pos = kallsyms_token_index[0xff];
	total_size += pos + strlen(&kallsyms_token_table[pos]) + 1;
	total_size += 0x100 * sizeof(u16);

	pr_info(" ---------------------------------------------------------\n");
	pr_info("| nr_symbols | compressed size | original size | ratio(%%) |\n");
	pr_info("|---------------------------------------------------------|\n");
	ratio = (u32)div_u64(10000ULL * total_size, total_len);
	pr_info("| %10d |    %10d   |   %10d  |  %2d.%-2d   |\n",
		kallsyms_num_syms, total_size, total_len, ratio / 100, ratio % 100);
	pr_info(" ---------------------------------------------------------\n");
}

static int lookup_name(void *data, const char *name, struct module *mod, unsigned long addr)
{
	u64 t0, t1, t;
	unsigned long flags;
	struct test_stat *stat = (struct test_stat *)data;

	local_irq_save(flags);
	t0 = sched_clock();
	(void)kallsyms_lookup_name(name);
	t1 = sched_clock();
	local_irq_restore(flags);

	t = t1 - t0;
	if (t < stat->min)
		stat->min = t;

	if (t > stat->max)
		stat->max = t;

	stat->real_cnt++;
	stat->sum += t;

	return 0;
}

static void test_perf_kallsyms_lookup_name(void)
{
	struct test_stat stat;

	memset(&stat, 0, sizeof(stat));
	stat.min = INT_MAX;
	kallsyms_on_each_symbol(lookup_name, &stat);
	pr_info("kallsyms_lookup_name() looked up %d symbols\n", stat.real_cnt);
	pr_info("The time spent on each symbol is (ns): min=%d, max=%d, avg=%lld\n",
		stat.min, stat.max, div_u64(stat.sum, stat.real_cnt));
}

static bool match_cleanup_name(const char *s, const char *name)
{
	char *p;
	int len;

	if (!IS_ENABLED(CONFIG_LTO_CLANG))
		return false;

	p = strchr(s, '.');
	if (!p)
		return false;

	len = strlen(name);
	if (p - s != len)
		return false;

	return !strncmp(s, name, len);
}

static int find_symbol(void *data, const char *name, struct module *mod, unsigned long addr)
{
	struct test_stat *stat = (struct test_stat *)data;

	if (strcmp(name, stat->name) == 0 ||
	    (!stat->perf && match_cleanup_name(name, stat->name))) {
		stat->real_cnt++;
		stat->addr = addr;

		if (stat->save_cnt < MAX_NUM_OF_RECORDS) {
			stat->addrs[stat->save_cnt] = addr;
			stat->save_cnt++;
		}

		if (stat->real_cnt == stat->max)
			return 1;
	}

	return 0;
}

static void test_perf_kallsyms_on_each_symbol(void)
{
	u64 t0, t1;
	unsigned long flags;
	struct test_stat stat;

	memset(&stat, 0, sizeof(stat));
	stat.max = INT_MAX;
	stat.name = stub_name;
	stat.perf = 1;
	local_irq_save(flags);
	t0 = sched_clock();
	kallsyms_on_each_symbol(find_symbol, &stat);
	t1 = sched_clock();
	local_irq_restore(flags);
	pr_info("kallsyms_on_each_symbol() traverse all: %lld ns\n", t1 - t0);
}

static int match_symbol(void *data, unsigned long addr)
{
	struct test_stat *stat = (struct test_stat *)data;

	stat->real_cnt++;
	stat->addr = addr;

	if (stat->save_cnt < MAX_NUM_OF_RECORDS) {
		stat->addrs[stat->save_cnt] = addr;
		stat->save_cnt++;
	}

	if (stat->real_cnt == stat->max)
		return 1;

	return 0;
}

static void test_perf_kallsyms_on_each_match_symbol(void)
{
	u64 t0, t1;
	unsigned long flags;
	struct test_stat stat;

	memset(&stat, 0, sizeof(stat));
	stat.max = INT_MAX;
	stat.name = stub_name;
	local_irq_save(flags);
	t0 = sched_clock();
	kallsyms_on_each_match_symbol(match_symbol, stat.name, &stat);
	t1 = sched_clock();
	local_irq_restore(flags);
	pr_info("kallsyms_on_each_match_symbol() traverse all: %lld ns\n", t1 - t0);
}

static int test_kallsyms_basic_function(void)
{
	int i, j, ret;
	int next = 0, nr_failed = 0;
	char *prefix;
	unsigned short rand;
	unsigned long addr, lookup_addr;
	char namebuf[KSYM_NAME_LEN];
	struct test_stat *stat, *stat2;

	stat = kmalloc(sizeof(*stat) * 2, GFP_KERNEL);
	if (!stat)
		return -ENOMEM;
	stat2 = stat + 1;

	prefix = "kallsyms_lookup_name() for";
	for (i = 0; i < ARRAY_SIZE(test_items); i++) {
		addr = kallsyms_lookup_name(test_items[i].name);
		if (addr != test_items[i].addr) {
			nr_failed++;
			pr_info("%s %s failed: addr=%lx, expect %lx\n",
				prefix, test_items[i].name, addr, test_items[i].addr);
		}
	}

	prefix = "kallsyms_on_each_symbol() for";
	for (i = 0; i < ARRAY_SIZE(test_items); i++) {
		memset(stat, 0, sizeof(*stat));
		stat->max = INT_MAX;
		stat->name = test_items[i].name;
		kallsyms_on_each_symbol(find_symbol, stat);
		if (stat->addr != test_items[i].addr || stat->real_cnt != 1) {
			nr_failed++;
			pr_info("%s %s failed: count=%d, addr=%lx, expect %lx\n",
				prefix, test_items[i].name,
				stat->real_cnt, stat->addr, test_items[i].addr);
		}
	}

	prefix = "kallsyms_on_each_match_symbol() for";
	for (i = 0; i < ARRAY_SIZE(test_items); i++) {
		memset(stat, 0, sizeof(*stat));
		stat->max = INT_MAX;
		stat->name = test_items[i].name;
		kallsyms_on_each_match_symbol(match_symbol, test_items[i].name, stat);
		if (stat->addr != test_items[i].addr || stat->real_cnt != 1) {
			nr_failed++;
			pr_info("%s %s failed: count=%d, addr=%lx, expect %lx\n",
				prefix, test_items[i].name,
				stat->real_cnt, stat->addr, test_items[i].addr);
		}
	}

	if (nr_failed) {
		kfree(stat);
		return -ESRCH;
	}

	for (i = 0; i < kallsyms_num_syms; i++) {
		addr = kallsyms_sym_address(i);
		if (!is_ksym_addr(addr))
			continue;

		ret = lookup_symbol_name(addr, namebuf);
		if (unlikely(ret)) {
			namebuf[0] = 0;
			goto failed;
		}

		/*
		 * The first '.' may be the initial letter, in which case the
		 * entire symbol name will be truncated to an empty string in
		 * cleanup_symbol_name(). Do not test these symbols.
		 *
		 * For example:
		 * cat /proc/kallsyms | awk '{print $3}' | grep -E "^\." | head
		 * .E_read_words
		 * .E_leading_bytes
		 * .E_trailing_bytes
		 * .E_write_words
		 * .E_copy
		 * .str.292.llvm.12122243386960820698
		 * .str.24.llvm.12122243386960820698
		 * .str.29.llvm.12122243386960820698
		 * .str.75.llvm.12122243386960820698
		 * .str.99.llvm.12122243386960820698
		 */
		if (IS_ENABLED(CONFIG_LTO_CLANG) && !namebuf[0])
			continue;

		lookup_addr = kallsyms_lookup_name(namebuf);

		memset(stat, 0, sizeof(*stat));
		stat->max = INT_MAX;
		kallsyms_on_each_match_symbol(match_symbol, namebuf, stat);

		/*
		 * kallsyms_on_each_symbol() is too slow, randomly select some
		 * symbols for test.
		 */
		if (i >= next) {
			memset(stat2, 0, sizeof(*stat2));
			stat2->max = INT_MAX;
			stat2->name = namebuf;
			kallsyms_on_each_symbol(find_symbol, stat2);

			/*
			 * kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol()
			 * need to get the same traversal result.
			 */
			if (stat->addr != stat2->addr ||
			    stat->real_cnt != stat2->real_cnt ||
			    memcmp(stat->addrs, stat2->addrs,
				   stat->save_cnt * sizeof(stat->addrs[0])))
				goto failed;

			/*
			 * The average of random increments is 128, that is, one of
			 * them is tested every 128 symbols.
			 */
			get_random_bytes(&rand, sizeof(rand));
			next = i + (rand & 0xff) + 1;
		}

		/* Need to be found at least once */
		if (!stat->real_cnt)
			goto failed;

		/*
		 * kallsyms_lookup_name() returns the address of the first
		 * symbol found and cannot be NULL.
		 */
		if (!lookup_addr || lookup_addr != stat->addrs[0])
			goto failed;

		/*
		 * If the addresses of all matching symbols are recorded, the
		 * target address needs to be exist.
		 */
		if (stat->real_cnt <= MAX_NUM_OF_RECORDS) {
			for (j = 0; j < stat->save_cnt; j++) {
				if (stat->addrs[j] == addr)
					break;
			}

			if (j == stat->save_cnt)
				goto failed;
		}
	}

	kfree(stat);

	return 0;

failed:
	pr_info("Test for %dth symbol failed: (%s) addr=%lx", i, namebuf, addr);
	kfree(stat);
	return -ESRCH;
}

static int test_entry(void *p)
{
	int ret;

	do {
		schedule_timeout(5 * HZ);
	} while (system_state != SYSTEM_RUNNING);

	pr_info("start\n");
	ret = test_kallsyms_basic_function();
	if (ret) {
		pr_info("abort\n");
		return 0;
	}

	test_kallsyms_compression_ratio();
	test_perf_kallsyms_lookup_name();
	test_perf_kallsyms_on_each_symbol();
	test_perf_kallsyms_on_each_match_symbol();
	pr_info("finish\n");

	return 0;
}

static int __init kallsyms_test_init(void)
{
	struct task_struct *t;

	t = kthread_create(test_entry, NULL, "kallsyms_test");
	if (IS_ERR(t)) {
		pr_info("Create kallsyms selftest task failed\n");
		return PTR_ERR(t);
	}
	kthread_bind(t, 0);
	wake_up_process(t);

	return 0;
}
late_initcall(kallsyms_test_init);
Commit	Line	Data
30f3bb09 ZL	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Test the function and performance of kallsyms
	4	*
	5	* Copyright (C) Huawei Technologies Co., Ltd., 2022
	6	*
	7	* Authors: Zhen Lei <thunder.leizhen@huawei.com> Huawei
	8	*/
	9
	10	#define pr_fmt(fmt) "kallsyms_selftest: " fmt
	11
	12	#include <linux/init.h>
	13	#include <linux/module.h>
	14	#include <linux/kallsyms.h>
	15	#include <linux/random.h>
	16	#include <linux/sched/clock.h>
	17	#include <linux/kthread.h>
	18	#include <linux/vmalloc.h>
	19
	20	#include "kallsyms_internal.h"
	21	#include "kallsyms_selftest.h"
	22
	23
	24	#define MAX_NUM_OF_RECORDS 64
	25
	26	struct test_stat {
	27	int min;
	28	int max;
	29	int save_cnt;
	30	int real_cnt;
	31	int perf;
	32	u64 sum;
	33	char *name;
	34	unsigned long addr;
	35	unsigned long addrs[MAX_NUM_OF_RECORDS];
	36	};
	37
	38	struct test_item {
	39	char *name;
	40	unsigned long addr;
	41	};
	42
	43	#define ITEM_FUNC(s) \
	44	{ \
	45	.name = #s, \
	46	.addr = (unsigned long)s, \
	47	}
	48
	49	#define ITEM_DATA(s) \
	50	{ \
	51	.name = #s, \
	52	.addr = (unsigned long)&s, \
	53	}
	54
	55
	56	static int kallsyms_test_var_bss_static;
	57	static int kallsyms_test_var_data_static = 1;
	58	int kallsyms_test_var_bss;
	59	int kallsyms_test_var_data = 1;
	60
	61	static int kallsyms_test_func_static(void)
	62	{
	63	kallsyms_test_var_bss_static++;
	64	kallsyms_test_var_data_static++;
65
66	return 0;
67	}
68
69	int kallsyms_test_func(void)
70	{
71	return kallsyms_test_func_static();
72	}
73
74	__weak int kallsyms_test_func_weak(void)
75	{
76	kallsyms_test_var_bss++;
77	kallsyms_test_var_data++;
78	return 0;
79	}
80
81	static struct test_item test_items[] = {
82	ITEM_FUNC(kallsyms_test_func_static),
83	ITEM_FUNC(kallsyms_test_func),
84	ITEM_FUNC(kallsyms_test_func_weak),
85	ITEM_FUNC(vmalloc),
86	ITEM_FUNC(vfree),
87	#ifdef CONFIG_KALLSYMS_ALL
88	ITEM_DATA(kallsyms_test_var_bss_static),
89	ITEM_DATA(kallsyms_test_var_data_static),
90	ITEM_DATA(kallsyms_test_var_bss),
91	ITEM_DATA(kallsyms_test_var_data),
92	ITEM_DATA(vmap_area_list),
93	#endif
94	};
95
96	static char stub_name[KSYM_NAME_LEN];
97
98	static int stat_symbol_len(void data, const char name, struct module *mod, unsigned long addr)
99	{
100	(u32 )data += strlen(name);
101
102	return 0;
103	}
104
105	static void test_kallsyms_compression_ratio(void)
106	{
107	u32 pos, off, len, num;
108	u32 ratio, total_size, total_len = 0;
109
110	kallsyms_on_each_symbol(stat_symbol_len, &total_len);
111
112	/*
113	* A symbol name cannot start with a number. This stub name helps us
114	* traverse the entire symbol table without finding a match. It's used
115	* for subsequent performance tests, and its length is the average
116	* length of all symbol names.
117	*/
118	memset(stub_name, '4', sizeof(stub_name));
119	pos = total_len / kallsyms_num_syms;
120	stub_name[pos] = 0;
121
122	pos = 0;
123	num = 0;
124	off = 0;
125	while (pos < kallsyms_num_syms) {
126	len = kallsyms_names[off];
127	num++;
128	off++;
129	pos++;
130	if ((len & 0x80) != 0) {
131	len = (len & 0x7f) \| (kallsyms_names[off] << 7);
132	num++;
133	off++;
134	}
135	off += len;
c86a514f	136	}
30f3bb09 ZL	137
	138	/*
	139	* 1. The length fields is not counted
	140	* 2. The memory occupied by array kallsyms_token_table[] and
	141	* kallsyms_token_index[] needs to be counted.
	142	*/
	143	total_size = off - num;
	144	pos = kallsyms_token_index[0xff];
	145	total_size += pos + strlen(&kallsyms_token_table[pos]) + 1;
	146	total_size += 0x100 * sizeof(u16);
	147
	148	pr_info(" ---------------------------------------------------------\n");
	149	pr_info("\| nr_symbols \| compressed size \| original size \| ratio(%%) \|\n");
	150	pr_info("\|---------------------------------------------------------\|\n");
	151	ratio = (u32)div_u64(10000ULL * total_size, total_len);
	152	pr_info("\| %10d \| %10d \| %10d \| %2d.%-2d \|\n",
	153	kallsyms_num_syms, total_size, total_len, ratio / 100, ratio % 100);
	154	pr_info(" ---------------------------------------------------------\n");
	155	}
	156
	157	static int lookup_name(void data, const char name, struct module *mod, unsigned long addr)
	158	{
	159	u64 t0, t1, t;
	160	unsigned long flags;
	161	struct test_stat stat = (struct test_stat )data;
	162
	163	local_irq_save(flags);
	164	t0 = sched_clock();
	165	(void)kallsyms_lookup_name(name);
	166	t1 = sched_clock();
	167	local_irq_restore(flags);
	168
	169	t = t1 - t0;
	170	if (t < stat->min)
	171	stat->min = t;
	172
	173	if (t > stat->max)
	174	stat->max = t;
	175
	176	stat->real_cnt++;
	177	stat->sum += t;
	178
	179	return 0;
	180	}
	181
	182	static void test_perf_kallsyms_lookup_name(void)
	183	{
	184	struct test_stat stat;
	185
	186	memset(&stat, 0, sizeof(stat));
	187	stat.min = INT_MAX;
	188	kallsyms_on_each_symbol(lookup_name, &stat);
	189	pr_info("kallsyms_lookup_name() looked up %d symbols\n", stat.real_cnt);
	190	pr_info("The time spent on each symbol is (ns): min=%d, max=%d, avg=%lld\n",
	191	stat.min, stat.max, div_u64(stat.sum, stat.real_cnt));
	192	}
	193
	194	static bool match_cleanup_name(const char s, const char name)
	195	{
	196	char *p;
	197	int len;
	198
	199	if (!IS_ENABLED(CONFIG_LTO_CLANG))
	200	return false;
201
202	p = strchr(s, '.');
203	if (!p)
204	return false;
205
206	len = strlen(name);
207	if (p - s != len)
208	return false;
209
210	return !strncmp(s, name, len);
211	}
212
213	static int find_symbol(void data, const char name, struct module *mod, unsigned long addr)
214	{
215	struct test_stat stat = (struct test_stat )data;
216
217	if (strcmp(name, stat->name) == 0 \|\|
218	(!stat->perf && match_cleanup_name(name, stat->name))) {
219	stat->real_cnt++;
220	stat->addr = addr;
221
222	if (stat->save_cnt < MAX_NUM_OF_RECORDS) {
223	stat->addrs[stat->save_cnt] = addr;
224	stat->save_cnt++;
225	}
226
227	if (stat->real_cnt == stat->max)
228	return 1;
229	}
230
231	return 0;
232	}
233
234	static void test_perf_kallsyms_on_each_symbol(void)
235	{
236	u64 t0, t1;
237	unsigned long flags;
238	struct test_stat stat;
239
240	memset(&stat, 0, sizeof(stat));
241	stat.max = INT_MAX;
242	stat.name = stub_name;
243	stat.perf = 1;
244	local_irq_save(flags);
245	t0 = sched_clock();
246	kallsyms_on_each_symbol(find_symbol, &stat);
247	t1 = sched_clock();
248	local_irq_restore(flags);
249	pr_info("kallsyms_on_each_symbol() traverse all: %lld ns\n", t1 - t0);
250	}
251
252	static int match_symbol(void *data, unsigned long addr)
253	{
254	struct test_stat stat = (struct test_stat )data;
255
256	stat->real_cnt++;
257	stat->addr = addr;
258
259	if (stat->save_cnt < MAX_NUM_OF_RECORDS) {
260	stat->addrs[stat->save_cnt] = addr;
261	stat->save_cnt++;
262	}
263
264	if (stat->real_cnt == stat->max)
265	return 1;
266
267	return 0;
268	}
269
270	static void test_perf_kallsyms_on_each_match_symbol(void)
271	{
272	u64 t0, t1;
273	unsigned long flags;
274	struct test_stat stat;
275
276	memset(&stat, 0, sizeof(stat));
277	stat.max = INT_MAX;
278	stat.name = stub_name;
279	local_irq_save(flags);
280	t0 = sched_clock();
281	kallsyms_on_each_match_symbol(match_symbol, stat.name, &stat);
282	t1 = sched_clock();
283	local_irq_restore(flags);
284	pr_info("kallsyms_on_each_match_symbol() traverse all: %lld ns\n", t1 - t0);
285	}
286
287	static int test_kallsyms_basic_function(void)
288	{
289	int i, j, ret;
290	int next = 0, nr_failed = 0;
291	char *prefix;
292	unsigned short rand;
293	unsigned long addr, lookup_addr;
294	char namebuf[KSYM_NAME_LEN];
295	struct test_stat stat, stat2;
296
297	stat = kmalloc(sizeof(stat) 2, GFP_KERNEL);
298	if (!stat)
299	return -ENOMEM;
300	stat2 = stat + 1;
301
302	prefix = "kallsyms_lookup_name() for";
303	for (i = 0; i < ARRAY_SIZE(test_items); i++) {
304	addr = kallsyms_lookup_name(test_items[i].name);
305	if (addr != test_items[i].addr) {
306	nr_failed++;
307	pr_info("%s %s failed: addr=%lx, expect %lx\n",
308	prefix, test_items[i].name, addr, test_items[i].addr);
309	}
310	}
311
312	prefix = "kallsyms_on_each_symbol() for";
313	for (i = 0; i < ARRAY_SIZE(test_items); i++) {
314	memset(stat, 0, sizeof(*stat));
315	stat->max = INT_MAX;
316	stat->name = test_items[i].name;
317	kallsyms_on_each_symbol(find_symbol, stat);
318	if (stat->addr != test_items[i].addr \|\| stat->real_cnt != 1) {
319	nr_failed++;
320	pr_info("%s %s failed: count=%d, addr=%lx, expect %lx\n",
321	prefix, test_items[i].name,
322	stat->real_cnt, stat->addr, test_items[i].addr);
323	}
324	}
325
326	prefix = "kallsyms_on_each_match_symbol() for";
327	for (i = 0; i < ARRAY_SIZE(test_items); i++) {
328	memset(stat, 0, sizeof(*stat));
329	stat->max = INT_MAX;
330	stat->name = test_items[i].name;
331	kallsyms_on_each_match_symbol(match_symbol, test_items[i].name, stat);
332	if (stat->addr != test_items[i].addr \|\| stat->real_cnt != 1) {
333	nr_failed++;
334	pr_info("%s %s failed: count=%d, addr=%lx, expect %lx\n",
335	prefix, test_items[i].name,
336	stat->real_cnt, stat->addr, test_items[i].addr);
337	}
338	}
339
340	if (nr_failed) {
341	kfree(stat);
342	return -ESRCH;
343	}
344
345	for (i = 0; i < kallsyms_num_syms; i++) {
346	addr = kallsyms_sym_address(i);
347	if (!is_ksym_addr(addr))
348	continue;
349
350	ret = lookup_symbol_name(addr, namebuf);
351	if (unlikely(ret)) {
352	namebuf[0] = 0;
353	goto failed;
354	}
355
356	/*
357	* The first '.' may be the initial letter, in which case the
358	* entire symbol name will be truncated to an empty string in
359	* cleanup_symbol_name(). Do not test these symbols.
360	*
361	* For example:
362	* cat /proc/kallsyms \| awk '{print $3}' \| grep -E "^\." \| head
363	* .E_read_words
364	* .E_leading_bytes
365	* .E_trailing_bytes
366	* .E_write_words
367	* .E_copy
368	* .str.292.llvm.12122243386960820698
369	* .str.24.llvm.12122243386960820698
370	* .str.29.llvm.12122243386960820698
371	* .str.75.llvm.12122243386960820698
372	* .str.99.llvm.12122243386960820698
373	*/
374	if (IS_ENABLED(CONFIG_LTO_CLANG) && !namebuf[0])
375	continue;
376
377	lookup_addr = kallsyms_lookup_name(namebuf);
378
379	memset(stat, 0, sizeof(*stat));
380	stat->max = INT_MAX;
381	kallsyms_on_each_match_symbol(match_symbol, namebuf, stat);
382
383	/*
384	* kallsyms_on_each_symbol() is too slow, randomly select some
385	* symbols for test.
386	*/
387	if (i >= next) {
388	memset(stat2, 0, sizeof(*stat2));
389	stat2->max = INT_MAX;
390	stat2->name = namebuf;
391	kallsyms_on_each_symbol(find_symbol, stat2);
392
393	/*
394	* kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol()
395	* need to get the same traversal result.
396	*/
397	if (stat->addr != stat2->addr \|\|
398	stat->real_cnt != stat2->real_cnt \|\|
399	memcmp(stat->addrs, stat2->addrs,
400	stat->save_cnt * sizeof(stat->addrs[0])))
401	goto failed;
402
403	/*
404	* The average of random increments is 128, that is, one of
405	* them is tested every 128 symbols.
406	*/
407	get_random_bytes(&rand, sizeof(rand));
408	next = i + (rand & 0xff) + 1;
409	}
410
411	/* Need to be found at least once */
412	if (!stat->real_cnt)
413	goto failed;
414
415	/*
416	* kallsyms_lookup_name() returns the address of the first
417	* symbol found and cannot be NULL.
418	*/
419	if (!lookup_addr \|\| lookup_addr != stat->addrs[0])
420	goto failed;
421
422	/*
423	* If the addresses of all matching symbols are recorded, the
424	* target address needs to be exist.
425	*/
426	if (stat->real_cnt <= MAX_NUM_OF_RECORDS) {
427	for (j = 0; j < stat->save_cnt; j++) {
428	if (stat->addrs[j] == addr)
429	break;
430	}
431
432	if (j == stat->save_cnt)
433	goto failed;
434	}
435	}
436
437	kfree(stat);
438
439	return 0;
440
441	failed:
442	pr_info("Test for %dth symbol failed: (%s) addr=%lx", i, namebuf, addr);
443	kfree(stat);
444	return -ESRCH;
445	}
446
447	static int test_entry(void *p)
448	{
449	int ret;
450
451	do {
452	schedule_timeout(5 * HZ);
453	} while (system_state != SYSTEM_RUNNING);
454
455	pr_info("start\n");
456	ret = test_kallsyms_basic_function();
457	if (ret) {
458	pr_info("abort\n");
459	return 0;
460	}
461
462	test_kallsyms_compression_ratio();
463	test_perf_kallsyms_lookup_name();
464	test_perf_kallsyms_on_each_symbol();
465	test_perf_kallsyms_on_each_match_symbol();
466	pr_info("finish\n");
467
468	return 0;
469	}
470
471	static int __init kallsyms_test_init(void)
472	{
473	struct task_struct *t;
474
475	t = kthread_create(test_entry, NULL, "kallsyms_test");
476	if (IS_ERR(t)) {
477	pr_info("Create kallsyms selftest task failed\n");
478	return PTR_ERR(t);
479	}
480	kthread_bind(t, 0);
481	wake_up_process(t);
482
483	return 0;
484	}
485	late_initcall(kallsyms_test_init);