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}
223