214 lines
4.6 KiB
C
214 lines
4.6 KiB
C
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/* Copyright (c) 2016 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <string.h>
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#include <fcntl.h>
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#include <poll.h>
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#include <sys/ioctl.h>
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#include <linux/perf_event.h>
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#include <linux/bpf.h>
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#include <signal.h>
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#include <assert.h>
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#include <errno.h>
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#include <sys/resource.h>
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#include "libbpf.h"
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#include "bpf_load.h"
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#define SAMPLE_FREQ 50
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static bool sys_read_seen, sys_write_seen;
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static void print_ksym(__u64 addr)
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{
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struct ksym *sym;
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if (!addr)
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return;
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sym = ksym_search(addr);
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printf("%s;", sym->name);
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if (!strcmp(sym->name, "sys_read"))
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sys_read_seen = true;
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else if (!strcmp(sym->name, "sys_write"))
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sys_write_seen = true;
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}
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static void print_addr(__u64 addr)
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{
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if (!addr)
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return;
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printf("%llx;", addr);
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}
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#define TASK_COMM_LEN 16
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struct key_t {
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char comm[TASK_COMM_LEN];
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__u32 kernstack;
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__u32 userstack;
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};
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static void print_stack(struct key_t *key, __u64 count)
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{
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__u64 ip[PERF_MAX_STACK_DEPTH] = {};
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static bool warned;
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int i;
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printf("%3lld %s;", count, key->comm);
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if (bpf_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
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printf("---;");
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} else {
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for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
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print_ksym(ip[i]);
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}
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printf("-;");
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if (bpf_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
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printf("---;");
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} else {
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for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
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print_addr(ip[i]);
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}
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printf("\n");
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if (key->kernstack == -EEXIST && !warned) {
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printf("stackmap collisions seen. Consider increasing size\n");
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warned = true;
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} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
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printf("err stackid %d %d\n", key->kernstack, key->userstack);
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}
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}
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static void int_exit(int sig)
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{
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kill(0, SIGKILL);
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exit(0);
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}
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static void print_stacks(void)
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{
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struct key_t key = {}, next_key;
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__u64 value;
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__u32 stackid = 0, next_id;
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int fd = map_fd[0], stack_map = map_fd[1];
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sys_read_seen = sys_write_seen = false;
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while (bpf_get_next_key(fd, &key, &next_key) == 0) {
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bpf_lookup_elem(fd, &next_key, &value);
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print_stack(&next_key, value);
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bpf_delete_elem(fd, &next_key);
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key = next_key;
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}
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if (!sys_read_seen || !sys_write_seen) {
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printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
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int_exit(0);
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}
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/* clear stack map */
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while (bpf_get_next_key(stack_map, &stackid, &next_id) == 0) {
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bpf_delete_elem(stack_map, &next_id);
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stackid = next_id;
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}
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}
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static void test_perf_event_all_cpu(struct perf_event_attr *attr)
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{
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int nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
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int *pmu_fd = malloc(nr_cpus * sizeof(int));
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int i;
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/* open perf_event on all cpus */
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for (i = 0; i < nr_cpus; i++) {
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pmu_fd[i] = perf_event_open(attr, -1, i, -1, 0);
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if (pmu_fd[i] < 0) {
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printf("perf_event_open failed\n");
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goto all_cpu_err;
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}
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assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
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assert(ioctl(pmu_fd[i], PERF_EVENT_IOC_ENABLE, 0) == 0);
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}
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system("dd if=/dev/zero of=/dev/null count=5000k");
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print_stacks();
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all_cpu_err:
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for (i--; i >= 0; i--)
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close(pmu_fd[i]);
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free(pmu_fd);
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}
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static void test_perf_event_task(struct perf_event_attr *attr)
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{
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int pmu_fd;
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/* open task bound event */
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pmu_fd = perf_event_open(attr, 0, -1, -1, 0);
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if (pmu_fd < 0) {
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printf("perf_event_open failed\n");
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return;
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}
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assert(ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd[0]) == 0);
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assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
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system("dd if=/dev/zero of=/dev/null count=5000k");
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print_stacks();
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close(pmu_fd);
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}
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static void test_bpf_perf_event(void)
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{
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struct perf_event_attr attr_type_hw = {
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.sample_freq = SAMPLE_FREQ,
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.freq = 1,
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.type = PERF_TYPE_HARDWARE,
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.config = PERF_COUNT_HW_CPU_CYCLES,
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.inherit = 1,
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};
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struct perf_event_attr attr_type_sw = {
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.sample_freq = SAMPLE_FREQ,
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.freq = 1,
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.type = PERF_TYPE_SOFTWARE,
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.config = PERF_COUNT_SW_CPU_CLOCK,
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.inherit = 1,
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};
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test_perf_event_all_cpu(&attr_type_hw);
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test_perf_event_task(&attr_type_hw);
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test_perf_event_all_cpu(&attr_type_sw);
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test_perf_event_task(&attr_type_sw);
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}
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int main(int argc, char **argv)
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{
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struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
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char filename[256];
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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setrlimit(RLIMIT_MEMLOCK, &r);
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signal(SIGINT, int_exit);
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if (load_kallsyms()) {
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printf("failed to process /proc/kallsyms\n");
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return 1;
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}
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if (load_bpf_file(filename)) {
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printf("%s", bpf_log_buf);
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return 2;
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}
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if (fork() == 0) {
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read_trace_pipe();
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return 0;
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}
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test_bpf_perf_event();
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int_exit(0);
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return 0;
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}
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