1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Test the function and performance of kallsyms
5 * Copyright (C) Huawei Technologies Co., Ltd., 2022
7 * Authors: Zhen Lei <thunder.leizhen@huawei.com> Huawei
10 #define pr_fmt(fmt) "kallsyms_selftest: " fmt
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>
20 #include "kallsyms_internal.h"
21 #include "kallsyms_selftest.h"
24 #define MAX_NUM_OF_RECORDS 64
35 unsigned long addrs
[MAX_NUM_OF_RECORDS
];
43 #define ITEM_FUNC(s) \
46 .addr = (unsigned long)s, \
49 #define ITEM_DATA(s) \
52 .addr = (unsigned long)&s, \
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;
61 static int kallsyms_test_func_static(void)
63 kallsyms_test_var_bss_static
++;
64 kallsyms_test_var_data_static
++;
69 int kallsyms_test_func(void)
71 return kallsyms_test_func_static();
74 __weak
int kallsyms_test_func_weak(void)
76 kallsyms_test_var_bss
++;
77 kallsyms_test_var_data
++;
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
),
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
),
96 static char stub_name
[KSYM_NAME_LEN
];
98 static int stat_symbol_len(void *data
, const char *name
, struct module
*mod
, unsigned long addr
)
100 *(u32
*)data
+= strlen(name
);
105 static void test_kallsyms_compression_ratio(void)
107 u32 pos
, off
, len
, num
;
108 u32 ratio
, total_size
, total_len
= 0;
110 kallsyms_on_each_symbol(stat_symbol_len
, &total_len
);
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.
118 memset(stub_name
, '4', sizeof(stub_name
));
119 pos
= total_len
/ kallsyms_num_syms
;
125 while (pos
< kallsyms_num_syms
) {
126 len
= kallsyms_names
[off
];
130 if ((len
& 0x80) != 0) {
131 len
= (len
& 0x7f) | (kallsyms_names
[off
] << 7);
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.
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
);
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");
157 static int lookup_name(void *data
, const char *name
, struct module
*mod
, unsigned long addr
)
161 struct test_stat
*stat
= (struct test_stat
*)data
;
163 local_irq_save(flags
);
165 (void)kallsyms_lookup_name(name
);
167 local_irq_restore(flags
);
182 static void test_perf_kallsyms_lookup_name(void)
184 struct test_stat stat
;
186 memset(&stat
, 0, sizeof(stat
));
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
));
194 static bool match_cleanup_name(const char *s
, const char *name
)
199 if (!IS_ENABLED(CONFIG_LTO_CLANG
))
210 return !strncmp(s
, name
, len
);
213 static int find_symbol(void *data
, const char *name
, struct module
*mod
, unsigned long addr
)
215 struct test_stat
*stat
= (struct test_stat
*)data
;
217 if (strcmp(name
, stat
->name
) == 0 ||
218 (!stat
->perf
&& match_cleanup_name(name
, stat
->name
))) {
222 if (stat
->save_cnt
< MAX_NUM_OF_RECORDS
) {
223 stat
->addrs
[stat
->save_cnt
] = addr
;
227 if (stat
->real_cnt
== stat
->max
)
234 static void test_perf_kallsyms_on_each_symbol(void)
238 struct test_stat stat
;
240 memset(&stat
, 0, sizeof(stat
));
242 stat
.name
= stub_name
;
244 local_irq_save(flags
);
246 kallsyms_on_each_symbol(find_symbol
, &stat
);
248 local_irq_restore(flags
);
249 pr_info("kallsyms_on_each_symbol() traverse all: %lld ns\n", t1
- t0
);
252 static int match_symbol(void *data
, unsigned long addr
)
254 struct test_stat
*stat
= (struct test_stat
*)data
;
259 if (stat
->save_cnt
< MAX_NUM_OF_RECORDS
) {
260 stat
->addrs
[stat
->save_cnt
] = addr
;
264 if (stat
->real_cnt
== stat
->max
)
270 static void test_perf_kallsyms_on_each_match_symbol(void)
274 struct test_stat stat
;
276 memset(&stat
, 0, sizeof(stat
));
278 stat
.name
= stub_name
;
279 local_irq_save(flags
);
281 kallsyms_on_each_match_symbol(match_symbol
, stat
.name
, &stat
);
283 local_irq_restore(flags
);
284 pr_info("kallsyms_on_each_match_symbol() traverse all: %lld ns\n", t1
- t0
);
287 static int test_kallsyms_basic_function(void)
290 int next
= 0, nr_failed
= 0;
293 unsigned long addr
, lookup_addr
;
294 char namebuf
[KSYM_NAME_LEN
];
295 struct test_stat
*stat
, *stat2
;
297 stat
= kmalloc(sizeof(*stat
) * 2, GFP_KERNEL
);
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
) {
307 pr_info("%s %s failed: addr=%lx, expect %lx\n",
308 prefix
, test_items
[i
].name
, addr
, test_items
[i
].addr
);
312 prefix
= "kallsyms_on_each_symbol() for";
313 for (i
= 0; i
< ARRAY_SIZE(test_items
); i
++) {
314 memset(stat
, 0, sizeof(*stat
));
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) {
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
);
326 prefix
= "kallsyms_on_each_match_symbol() for";
327 for (i
= 0; i
< ARRAY_SIZE(test_items
); i
++) {
328 memset(stat
, 0, sizeof(*stat
));
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) {
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
);
345 for (i
= 0; i
< kallsyms_num_syms
; i
++) {
346 addr
= kallsyms_sym_address(i
);
347 if (!is_ksym_addr(addr
))
350 ret
= lookup_symbol_name(addr
, namebuf
);
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.
362 * cat /proc/kallsyms | awk '{print $3}' | grep -E "^\." | head
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
374 if (IS_ENABLED(CONFIG_LTO_CLANG
) && !namebuf
[0])
377 lookup_addr
= kallsyms_lookup_name(namebuf
);
379 memset(stat
, 0, sizeof(*stat
));
381 kallsyms_on_each_match_symbol(match_symbol
, namebuf
, stat
);
384 * kallsyms_on_each_symbol() is too slow, randomly select some
388 memset(stat2
, 0, sizeof(*stat2
));
389 stat2
->max
= INT_MAX
;
390 stat2
->name
= namebuf
;
391 kallsyms_on_each_symbol(find_symbol
, stat2
);
394 * kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol()
395 * need to get the same traversal result.
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])))
404 * The average of random increments is 128, that is, one of
405 * them is tested every 128 symbols.
407 get_random_bytes(&rand
, sizeof(rand
));
408 next
= i
+ (rand
& 0xff) + 1;
411 /* Need to be found at least once */
416 * kallsyms_lookup_name() returns the address of the first
417 * symbol found and cannot be NULL.
419 if (!lookup_addr
|| lookup_addr
!= stat
->addrs
[0])
423 * If the addresses of all matching symbols are recorded, the
424 * target address needs to be exist.
426 if (stat
->real_cnt
<= MAX_NUM_OF_RECORDS
) {
427 for (j
= 0; j
< stat
->save_cnt
; j
++) {
428 if (stat
->addrs
[j
] == addr
)
432 if (j
== stat
->save_cnt
)
442 pr_info("Test for %dth symbol failed: (%s) addr=%lx", i
, namebuf
, addr
);
447 static int test_entry(void *p
)
452 schedule_timeout(5 * HZ
);
453 } while (system_state
!= SYSTEM_RUNNING
);
456 ret
= test_kallsyms_basic_function();
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();
471 static int __init
kallsyms_test_init(void)
473 struct task_struct
*t
;
475 t
= kthread_create(test_entry
, NULL
, "kallsyms_test");
477 pr_info("Create kallsyms selftest task failed\n");
485 late_initcall(kallsyms_test_init
);