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1// SPDX-License-Identifier: GPL-2.0
2#define _GNU_SOURCE
3
4#include <assert.h>
5#include <fcntl.h>
6#include <linux/perf_event.h>
7#include <sched.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <sys/ioctl.h>
11#include <sys/time.h>
12#include <sys/types.h>
13#include <sys/wait.h>
14#include <unistd.h>
15
16#include <bpf/bpf.h>
17#include <bpf/libbpf.h>
18#include "perf-sys.h"
19
20#define SAMPLE_PERIOD 0x7fffffffffffffffULL
21
22/* counters, values, values2 */
23static int map_fd[3];
24
25static void check_on_cpu(int cpu, struct perf_event_attr *attr)
26{
27 struct bpf_perf_event_value value2;
28 int pmu_fd, error = 0;
29 cpu_set_t set;
30 __u64 value;
31
32 /* Move to target CPU */
33 CPU_ZERO(&set);
34 CPU_SET(cpu, &set);
35 assert(sched_setaffinity(0, sizeof(set), &set) == 0);
36 /* Open perf event and attach to the perf_event_array */
37 pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
38 if (pmu_fd < 0) {
39 fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
40 error = 1;
41 goto on_exit;
42 }
43 assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
44 assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
45 /* Trigger the kprobe */
46 bpf_map_get_next_key(map_fd[1], &cpu, NULL);
47 /* Check the value */
48 if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
49 fprintf(stderr, "Value missing for CPU %d\n", cpu);
50 error = 1;
51 goto on_exit;
52 } else {
53 fprintf(stderr, "CPU %d: %llu\n", cpu, value);
54 }
55 /* The above bpf_map_lookup_elem should trigger the second kprobe */
56 if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
57 fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
58 error = 1;
59 goto on_exit;
60 } else {
61 fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
62 value2.counter, value2.enabled, value2.running);
63 }
64
65on_exit:
66 assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
67 assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
68 assert(close(pmu_fd) == 0 || error);
69 assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
70 exit(error);
71}
72
73static void test_perf_event_array(struct perf_event_attr *attr,
74 const char *name)
75{
76 int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
77 pid_t pid[nr_cpus];
78 int err = 0;
79
80 printf("Test reading %s counters\n", name);
81
82 for (i = 0; i < nr_cpus; i++) {
83 pid[i] = fork();
84 assert(pid[i] >= 0);
85 if (pid[i] == 0) {
86 check_on_cpu(i, attr);
87 exit(1);
88 }
89 }
90
91 for (i = 0; i < nr_cpus; i++) {
92 assert(waitpid(pid[i], &status, 0) == pid[i]);
93 err |= status;
94 }
95
96 if (err)
97 printf("Test: %s FAILED\n", name);
98}
99
100static void test_bpf_perf_event(void)
101{
102 struct perf_event_attr attr_cycles = {
103 .freq = 0,
104 .sample_period = SAMPLE_PERIOD,
105 .inherit = 0,
106 .type = PERF_TYPE_HARDWARE,
107 .read_format = 0,
108 .sample_type = 0,
109 .config = PERF_COUNT_HW_CPU_CYCLES,
110 };
111 struct perf_event_attr attr_clock = {
112 .freq = 0,
113 .sample_period = SAMPLE_PERIOD,
114 .inherit = 0,
115 .type = PERF_TYPE_SOFTWARE,
116 .read_format = 0,
117 .sample_type = 0,
118 .config = PERF_COUNT_SW_CPU_CLOCK,
119 };
120 struct perf_event_attr attr_raw = {
121 .freq = 0,
122 .sample_period = SAMPLE_PERIOD,
123 .inherit = 0,
124 .type = PERF_TYPE_RAW,
125 .read_format = 0,
126 .sample_type = 0,
127 /* Intel Instruction Retired */
128 .config = 0xc0,
129 };
130 struct perf_event_attr attr_l1d_load = {
131 .freq = 0,
132 .sample_period = SAMPLE_PERIOD,
133 .inherit = 0,
134 .type = PERF_TYPE_HW_CACHE,
135 .read_format = 0,
136 .sample_type = 0,
137 .config =
138 PERF_COUNT_HW_CACHE_L1D |
139 (PERF_COUNT_HW_CACHE_OP_READ << 8) |
140 (PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
141 };
142 struct perf_event_attr attr_llc_miss = {
143 .freq = 0,
144 .sample_period = SAMPLE_PERIOD,
145 .inherit = 0,
146 .type = PERF_TYPE_HW_CACHE,
147 .read_format = 0,
148 .sample_type = 0,
149 .config =
150 PERF_COUNT_HW_CACHE_LL |
151 (PERF_COUNT_HW_CACHE_OP_READ << 8) |
152 (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
153 };
154 struct perf_event_attr attr_msr_tsc = {
155 .freq = 0,
156 .sample_period = 0,
157 .inherit = 0,
158 /* From /sys/bus/event_source/devices/msr/ */
159 .type = 7,
160 .read_format = 0,
161 .sample_type = 0,
162 .config = 0,
163 };
164
165 test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
166 test_perf_event_array(&attr_clock, "SOFTWARE-clock");
167 test_perf_event_array(&attr_raw, "RAW-instruction-retired");
168 test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
169
170 /* below tests may fail in qemu */
171 test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
172 test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
173}
174
175int main(int argc, char **argv)
176{
177 struct bpf_link *links[2];
178 struct bpf_program *prog;
179 struct bpf_object *obj;
180 char filename[256];
181 int i = 0;
182
183 snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
184 obj = bpf_object__open_file(filename, NULL);
185 if (libbpf_get_error(obj)) {
186 fprintf(stderr, "ERROR: opening BPF object file failed\n");
187 return 0;
188 }
189
190 /* load BPF program */
191 if (bpf_object__load(obj)) {
192 fprintf(stderr, "ERROR: loading BPF object file failed\n");
193 goto cleanup;
194 }
195
196 map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
197 map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
198 map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
199 if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
200 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
201 goto cleanup;
202 }
203
204 bpf_object__for_each_program(prog, obj) {
205 links[i] = bpf_program__attach(prog);
206 if (libbpf_get_error(links[i])) {
207 fprintf(stderr, "ERROR: bpf_program__attach failed\n");
208 links[i] = NULL;
209 goto cleanup;
210 }
211 i++;
212 }
213
214 test_bpf_perf_event();
215
216cleanup:
217 for (i--; i >= 0; i--)
218 bpf_link__destroy(links[i]);
219
220 bpf_object__close(obj);
221 return 0;
222}