// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2016 Facebook
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <linux/perf_event.h>
#include <linux/bpf.h>
#include <signal.h>
#include <errno.h>
#include <sys/resource.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "perf-sys.h"
#include "trace_helpers.h"
#define SAMPLE_FREQ 50
static int pid;
/* counts, stackmap */
static int map_fd[2];
struct bpf_program *prog;
static bool sys_read_seen, sys_write_seen;
static void print_ksym(__u64 addr)
{
struct ksym *sym;
if (!addr)
return;
sym = ksym_search(addr);
if (!sym) {
printf("ksym not found. Is kallsyms loaded?\n");
return;
}
printf("%s;", sym->name);
if (!strstr(sym->name, "sys_read"))
sys_read_seen = true;
else if (!strstr(sym->name, "sys_write"))
sys_write_seen = true;
}
static void print_addr(__u64 addr)
{
if (!addr)
return;
printf("%llx;", addr);
}
#define TASK_COMM_LEN 16
struct key_t {
char comm[TASK_COMM_LEN];
__u32 kernstack;
__u32 userstack;
};
static void print_stack(struct key_t *key, __u64 count)
{
__u64 ip[PERF_MAX_STACK_DEPTH] = {};
static bool warned;
int i;
printf("%3lld %s;", count, key->comm);
if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
printf("---;");
} else {
for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
print_ksym(ip[i]);
}
printf("-;");
if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
printf("---;");
} else {
for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
print_addr(ip[i]);
}
if (count < 6)
printf("\r");
else
printf("\n");
if (key->kernstack == -EEXIST && !warned) {
printf("stackmap collisions seen. Consider increasing size\n");
warned = true;
} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
printf("err stackid %d %d\n", key->kernstack, key->userstack);
}
}
static void err_exit(int err)
{
kill(pid, SIGKILL);
exit(err);
}
static void print_stacks(void)
{
struct key_t key = {}, next_key;
__u64 value;
__u32 stackid = 0, next_id;
int error = 1, fd = map_fd[0], stack_map = map_fd[1];
sys_read_seen = sys_write_seen = false;
while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
bpf_map_lookup_elem(fd, &next_key, &value);
print_stack(&next_key, value);
bpf_map_delete_elem(fd, &next_key);
key = next_key;
}
printf("\n");
if (!sys_read_seen || !sys_write_seen) {
printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
err_exit(error);
}
/* clear stack map */
while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
bpf_map_delete_elem(stack_map, &next_id);
stackid = next_id;
}
}
static inline int generate_load(void)
{
if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
printf("failed to generate some load with dd: %s\n", strerror(errno));
return -1;
}
return 0;
}
static void test_perf_event_all_cpu(struct perf_event_attr *attr)
{
int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *));
int i, pmu_fd, error = 1;
if (!links) {
printf("malloc of links failed\n");
goto err;
}
/* system wide perf event, no need to inherit */
attr->inherit = 0;
/* open perf_event on all cpus */
for (i = 0; i < nr_cpus; i++) {
pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0);
if (pmu_fd < 0) {
printf("sys_perf_event_open failed\n");
goto all_cpu_err;
}
links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
if (libbpf_get_error(links[i])) {
printf("bpf_program__attach_perf_event failed\n");
links[i] = NULL;
close(pmu_fd);
goto all_cpu_err;
}
}
if (generate_load() < 0)
goto all_cpu_err;
print_stacks();
error = 0;
all_cpu_err:
for (i--; i >= 0; i--)
bpf_link__destroy(links[i]);
err:
free(links);
if (error)
err_exit(error);
}
static void test_perf_event_task(struct perf_event_attr *attr)
{
struct bpf_link *link = NULL;
int pmu_fd, error = 1;
/* per task perf event, enable inherit so the "dd ..." command can be traced properly.
* Enabling inherit will cause bpf_perf_prog_read_time helper failure.
*/
attr->inherit = 1;
/* open task bound event */
pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
if (pmu_fd < 0) {
printf("sys_perf_event_open failed\n");
goto err;
}
link = bpf_program__attach_perf_event(prog, pmu_fd);
if (libbpf_get_error(link)) {
printf("bpf_program__attach_perf_event failed\n");
link = NULL;
close(pmu_fd);
goto err;
}
if (generate_load() < 0)
goto err;
print_stacks();
error = 0;
err:
bpf_link__destroy(link);
if (error)
err_exit(error);
}
static void test_bpf_perf_event(void)
{
struct perf_event_attr attr_type_hw = {
.sample_freq = SAMPLE_FREQ,
.freq = 1,
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
};
struct perf_event_attr attr_type_sw = {
.sample_freq = SAMPLE_FREQ,
.freq = 1,
.type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_CPU_CLOCK,
};
struct perf_event_attr attr_hw_cache_l1d = {
.sample_freq = SAMPLE_FREQ,
.freq = 1,
.type = PERF_TYPE_HW_CACHE,
.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_hw_cache_branch_miss = {
.sample_freq = SAMPLE_FREQ,
.freq = 1,
.type = PERF_TYPE_HW_CACHE,
.config =
PERF_COUNT_HW_CACHE_BPU |
(PERF_COUNT_HW_CACHE_OP_READ << 8) |
(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
};
struct perf_event_attr attr_type_raw = {
.sample_freq = SAMPLE_FREQ,
.freq = 1,
.type = PERF_TYPE_RAW,
/* Intel Instruction Retired */
.config = 0xc0,
};
struct perf_event_attr attr_type_raw_lock_load = {
.sample_freq = SAMPLE_FREQ,
.freq = 1,
.type = PERF_TYPE_RAW,
/* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
.config = 0x21d0,
/* Request to record lock address from PEBS */
.sample_type = PERF_SAMPLE_ADDR,
/* Record address value requires precise event */
.precise_ip = 2,
};
printf("Test HW_CPU_CYCLES\n");
test_perf_event_all_cpu(&attr_type_hw);
test_perf_event_task(&attr_type_hw);
printf("Test SW_CPU_CLOCK\n");
test_perf_event_all_cpu(&attr_type_sw);
test_perf_event_task(&attr_type_sw);
printf("Test HW_CACHE_L1D\n");
test_perf_event_all_cpu(&attr_hw_cache_l1d);
test_perf_event_task(&attr_hw_cache_l1d);
printf("Test HW_CACHE_BPU\n");
test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
test_perf_event_task(&attr_hw_cache_branch_miss);
printf("Test Instruction Retired\n");
test_perf_event_all_cpu(&attr_type_raw);
test_perf_event_task(&attr_type_raw);
printf("Test Lock Load\n");
test_perf_event_all_cpu(&attr_type_raw_lock_load);
test_perf_event_task(&attr_type_raw_lock_load);
printf("*** PASS ***\n");
}
int main(int argc, char **argv)
{
struct bpf_object *obj = NULL;
char filename[256];
int error = 1;
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
signal(SIGINT, err_exit);
signal(SIGTERM, err_exit);
if (load_kallsyms()) {
printf("failed to process /proc/kallsyms\n");
goto cleanup;
}
obj = bpf_object__open_file(filename, NULL);
if (libbpf_get_error(obj)) {
printf("opening BPF object file failed\n");
obj = NULL;
goto cleanup;
}
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
if (!prog) {
printf("finding a prog in obj file failed\n");
goto cleanup;
}
/* load BPF program */
if (bpf_object__load(obj)) {
printf("loading BPF object file failed\n");
goto cleanup;
}
map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
if (map_fd[0] < 0 || map_fd[1] < 0) {
printf("finding a counts/stackmap map in obj file failed\n");
goto cleanup;
}
pid = fork();
if (pid == 0) {
read_trace_pipe();
return 0;
} else if (pid == -1) {
printf("couldn't spawn process\n");
goto cleanup;
}
test_bpf_perf_event();
error = 0;
cleanup:
bpf_object__close(obj);
err_exit(error);
}
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