xref: /openbmc/linux/samples/bpf/tracex6_user.c (revision 6c33a6f4)
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 <linux/bpf.h>
8 #include <sched.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <sys/ioctl.h>
12 #include <sys/resource.h>
13 #include <sys/time.h>
14 #include <sys/types.h>
15 #include <sys/wait.h>
16 #include <unistd.h>
17 
18 #include "bpf_load.h"
19 #include <bpf/bpf.h>
20 #include "perf-sys.h"
21 
22 #define SAMPLE_PERIOD  0x7fffffffffffffffULL
23 
24 static void check_on_cpu(int cpu, struct perf_event_attr *attr)
25 {
26 	struct bpf_perf_event_value value2;
27 	int pmu_fd, error = 0;
28 	cpu_set_t set;
29 	__u64 value;
30 
31 	/* Move to target CPU */
32 	CPU_ZERO(&set);
33 	CPU_SET(cpu, &set);
34 	assert(sched_setaffinity(0, sizeof(set), &set) == 0);
35 	/* Open perf event and attach to the perf_event_array */
36 	pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
37 	if (pmu_fd < 0) {
38 		fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
39 		error = 1;
40 		goto on_exit;
41 	}
42 	assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
43 	assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
44 	/* Trigger the kprobe */
45 	bpf_map_get_next_key(map_fd[1], &cpu, NULL);
46 	/* Check the value */
47 	if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
48 		fprintf(stderr, "Value missing for CPU %d\n", cpu);
49 		error = 1;
50 		goto on_exit;
51 	} else {
52 		fprintf(stderr, "CPU %d: %llu\n", cpu, value);
53 	}
54 	/* The above bpf_map_lookup_elem should trigger the second kprobe */
55 	if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
56 		fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
57 		error = 1;
58 		goto on_exit;
59 	} else {
60 		fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
61 			value2.counter, value2.enabled, value2.running);
62 	}
63 
64 on_exit:
65 	assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
66 	assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
67 	assert(close(pmu_fd) == 0 || error);
68 	assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
69 	exit(error);
70 }
71 
72 static void test_perf_event_array(struct perf_event_attr *attr,
73 				  const char *name)
74 {
75 	int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
76 	pid_t pid[nr_cpus];
77 	int err = 0;
78 
79 	printf("Test reading %s counters\n", name);
80 
81 	for (i = 0; i < nr_cpus; i++) {
82 		pid[i] = fork();
83 		assert(pid[i] >= 0);
84 		if (pid[i] == 0) {
85 			check_on_cpu(i, attr);
86 			exit(1);
87 		}
88 	}
89 
90 	for (i = 0; i < nr_cpus; i++) {
91 		assert(waitpid(pid[i], &status, 0) == pid[i]);
92 		err |= status;
93 	}
94 
95 	if (err)
96 		printf("Test: %s FAILED\n", name);
97 }
98 
99 static void test_bpf_perf_event(void)
100 {
101 	struct perf_event_attr attr_cycles = {
102 		.freq = 0,
103 		.sample_period = SAMPLE_PERIOD,
104 		.inherit = 0,
105 		.type = PERF_TYPE_HARDWARE,
106 		.read_format = 0,
107 		.sample_type = 0,
108 		.config = PERF_COUNT_HW_CPU_CYCLES,
109 	};
110 	struct perf_event_attr attr_clock = {
111 		.freq = 0,
112 		.sample_period = SAMPLE_PERIOD,
113 		.inherit = 0,
114 		.type = PERF_TYPE_SOFTWARE,
115 		.read_format = 0,
116 		.sample_type = 0,
117 		.config = PERF_COUNT_SW_CPU_CLOCK,
118 	};
119 	struct perf_event_attr attr_raw = {
120 		.freq = 0,
121 		.sample_period = SAMPLE_PERIOD,
122 		.inherit = 0,
123 		.type = PERF_TYPE_RAW,
124 		.read_format = 0,
125 		.sample_type = 0,
126 		/* Intel Instruction Retired */
127 		.config = 0xc0,
128 	};
129 	struct perf_event_attr attr_l1d_load = {
130 		.freq = 0,
131 		.sample_period = SAMPLE_PERIOD,
132 		.inherit = 0,
133 		.type = PERF_TYPE_HW_CACHE,
134 		.read_format = 0,
135 		.sample_type = 0,
136 		.config =
137 			PERF_COUNT_HW_CACHE_L1D |
138 			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
139 			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
140 	};
141 	struct perf_event_attr attr_llc_miss = {
142 		.freq = 0,
143 		.sample_period = SAMPLE_PERIOD,
144 		.inherit = 0,
145 		.type = PERF_TYPE_HW_CACHE,
146 		.read_format = 0,
147 		.sample_type = 0,
148 		.config =
149 			PERF_COUNT_HW_CACHE_LL |
150 			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
151 			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
152 	};
153 	struct perf_event_attr attr_msr_tsc = {
154 		.freq = 0,
155 		.sample_period = 0,
156 		.inherit = 0,
157 		/* From /sys/bus/event_source/devices/msr/ */
158 		.type = 7,
159 		.read_format = 0,
160 		.sample_type = 0,
161 		.config = 0,
162 	};
163 
164 	test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
165 	test_perf_event_array(&attr_clock, "SOFTWARE-clock");
166 	test_perf_event_array(&attr_raw, "RAW-instruction-retired");
167 	test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
168 
169 	/* below tests may fail in qemu */
170 	test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
171 	test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
172 }
173 
174 int main(int argc, char **argv)
175 {
176 	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
177 	char filename[256];
178 
179 	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
180 
181 	setrlimit(RLIMIT_MEMLOCK, &r);
182 	if (load_bpf_file(filename)) {
183 		printf("%s", bpf_log_buf);
184 		return 1;
185 	}
186 
187 	test_bpf_perf_event();
188 	return 0;
189 }
190