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// SPDX-License-Identifier: GPL-2.0
#define _GNU_SOURCE
#include <assert.h>
#include <fcntl.h>
#include <linux/perf_event.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "perf-sys.h"
#define SAMPLE_PERIOD 0x7fffffffffffffffULL
/* counters, values, values2 */
static int map_fd[3];
static void check_on_cpu(int cpu, struct perf_event_attr *attr)
{
struct bpf_perf_event_value value2;
int pmu_fd, error = 0;
cpu_set_t set;
__u64 value;
/* Move to target CPU */
CPU_ZERO(&set);
CPU_SET(cpu, &set);
assert(sched_setaffinity(0, sizeof(set), &set) == 0);
/* Open perf event and attach to the perf_event_array */
pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
if (pmu_fd < 0) {
fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
error = 1;
goto on_exit;
}
assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
/* Trigger the kprobe */
bpf_map_get_next_key(map_fd[1], &cpu, NULL);
/* Check the value */
if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
fprintf(stderr, "Value missing for CPU %d\n", cpu);
error = 1;
goto on_exit;
} else {
fprintf(stderr, "CPU %d: %llu\n", cpu, value);
}
/* The above bpf_map_lookup_elem should trigger the second kprobe */
if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
error = 1;
goto on_exit;
} else {
fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
value2.counter, value2.enabled, value2.running);
}
on_exit:
assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
assert(close(pmu_fd) == 0 || error);
assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
exit(error);
}
static void test_perf_event_array(struct perf_event_attr *attr,
const char *name)
{
int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
pid_t pid[nr_cpus];
int err = 0;
printf("Test reading %s counters\n", name);
for (i = 0; i < nr_cpus; i++) {
pid[i] = fork();
assert(pid[i] >= 0);
if (pid[i] == 0) {
check_on_cpu(i, attr);
exit(1);
}
}
for (i = 0; i < nr_cpus; i++) {
assert(waitpid(pid[i], &status, 0) == pid[i]);
err |= status;
}
if (err)
printf("Test: %s FAILED\n", name);
}
static void test_bpf_perf_event(void)
{
struct perf_event_attr attr_cycles = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HARDWARE,
.read_format = 0,
.sample_type = 0,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
struct perf_event_attr attr_clock = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_SOFTWARE,
.read_format = 0,
.sample_type = 0,
.config = PERF_COUNT_SW_CPU_CLOCK,
};
struct perf_event_attr attr_raw = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_RAW,
.read_format = 0,
.sample_type = 0,
/* Intel Instruction Retired */
.config = 0xc0,
};
struct perf_event_attr attr_l1d_load = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HW_CACHE,
.read_format = 0,
.sample_type = 0,
.config =
PERF_COUNT_HW_CACHE_L1D |
(PERF_COUNT_HW_CACHE_OP_READ << 8) |
(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
};
struct perf_event_attr attr_llc_miss = {
.freq = 0,
.sample_period = SAMPLE_PERIOD,
.inherit = 0,
.type = PERF_TYPE_HW_CACHE,
.read_format = 0,
.sample_type = 0,
.config =
PERF_COUNT_HW_CACHE_LL |
(PERF_COUNT_HW_CACHE_OP_READ << 8) |
(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
};
struct perf_event_attr attr_msr_tsc = {
.freq = 0,
.sample_period = 0,
.inherit = 0,
/* From /sys/bus/event_source/devices/msr/ */
.type = 7,
.read_format = 0,
.sample_type = 0,
.config = 0,
};
test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
test_perf_event_array(&attr_clock, "SOFTWARE-clock");
test_perf_event_array(&attr_raw, "RAW-instruction-retired");
test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
/* below tests may fail in qemu */
test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
}
int main(int argc, char **argv)
{
struct bpf_link *links[2];
struct bpf_program *prog;
struct bpf_object *obj;
char filename[256];
int i = 0;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
fprintf(stderr, "ERROR: opening BPF object file failed\n");
return 0;
}
/* load BPF program */
if (bpf_object__load(obj)) {
fprintf(stderr, "ERROR: loading BPF object file failed\n");
goto cleanup;
}
map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
goto cleanup;
}
bpf_object__for_each_program(prog, obj) {
links[i] = bpf_program__attach(prog);
if (libbpf_get_error(links[i])) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
links[i] = NULL;
goto cleanup;
}
i++;
}
test_bpf_perf_event();
cleanup:
for (i--; i >= 0; i--)
bpf_link__destroy(links[i]);
bpf_object__close(obj);
return 0;
}
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