// 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 <[email protected]> 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_noprof),
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),
#endif
};
static char stub_name[KSYM_NAME_LEN];
static int stat_symbol_len(void *data, const char *name, 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, unsigned long addr)
{
u64 t0, t1, t;
struct test_stat *stat = (struct test_stat *)data;
t0 = ktime_get_ns();
(void)kallsyms_lookup_name(name);
t1 = ktime_get_ns();
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 int find_symbol(void *data, const char *name, unsigned long addr)
{
struct test_stat *stat = (struct test_stat *)data;
if (!strcmp(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;
struct test_stat stat;
memset(&stat, 0, sizeof(stat));
stat.max = INT_MAX;
stat.name = stub_name;
stat.perf = 1;
t0 = ktime_get_ns();
kallsyms_on_each_symbol(find_symbol, &stat);
t1 = ktime_get_ns();
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;
struct test_stat stat;
memset(&stat, 0, sizeof(stat));
stat.max = INT_MAX;
stat.name = stub_name;
t0 = ktime_get_ns();
kallsyms_on_each_match_symbol(match_symbol, stat.name, &stat);
t1 = ktime_get_ns();
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;
pr_info("%d: lookup_symbol_name(%lx) failed\n", i, addr);
goto failed;
}
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]))) {
pr_info("%s: mismatch between kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol()\n",
namebuf);
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) {
pr_info("%s: Never found\n", namebuf);
goto failed;
}
/*
* kallsyms_lookup_name() returns the address of the first
* symbol found and cannot be NULL.
*/
if (!lookup_addr) {
pr_info("%s: NULL lookup_addr?!\n", namebuf);
goto failed;
}
if (lookup_addr != stat->addrs[0]) {
pr_info("%s: lookup_addr != stat->addrs[0]\n", namebuf);
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) {
pr_info("%s: j == save_cnt?!\n", namebuf);
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);
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