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 */ 23 static int map_fd[3]; 24 25 static 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 65 on_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 73 static 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 } 99 100 static 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 } 174 175 int 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_kern.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(); 215 216 cleanup: 217 for (i--; i >= 0; i--) 218 bpf_link__destroy(links[i]); 219 220 bpf_object__close(obj); 221 return 0; 222 } 223