1 /* Copyright (c) 2016 Facebook
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
11 #include <linux/bpf.h>
13 #include <linux/perf_event.h>
17 #include <sys/resource.h>
20 #include "trace_helpers.h"
22 #define PRINT_RAW_ADDR 0
24 static void print_ksym(__u64 addr)
30 sym = ksym_search(addr);
32 printf("ksym not found. Is kallsyms loaded?\n");
37 printf("%s/%llx;", sym->name, addr);
39 printf("%s;", sym->name);
42 #define TASK_COMM_LEN 16
45 char waker[TASK_COMM_LEN];
46 char target[TASK_COMM_LEN];
51 static void print_stack(struct key_t *key, __u64 count)
53 __u64 ip[PERF_MAX_STACK_DEPTH] = {};
57 printf("%s;", key->target);
58 if (bpf_map_lookup_elem(map_fd[3], &key->tret, ip) != 0) {
61 for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
65 if (bpf_map_lookup_elem(map_fd[3], &key->wret, ip) != 0) {
68 for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
71 printf(";%s %lld\n", key->waker, count);
73 if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) {
74 printf("stackmap collisions seen. Consider increasing size\n");
76 } else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) {
77 printf("err stackid %d %d\n", key->tret, key->wret);
81 static void print_stacks(int fd)
83 struct key_t key = {}, next_key;
86 while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
87 bpf_map_lookup_elem(fd, &next_key, &value);
88 print_stack(&next_key, value);
93 static void int_exit(int sig)
95 print_stacks(map_fd[0]);
99 int main(int argc, char **argv)
101 struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
105 snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
106 setrlimit(RLIMIT_MEMLOCK, &r);
108 signal(SIGINT, int_exit);
109 signal(SIGTERM, int_exit);
111 if (load_kallsyms()) {
112 printf("failed to process /proc/kallsyms\n");
116 if (load_bpf_file(filename)) {
117 printf("%s", bpf_log_buf);
122 delay = atoi(argv[1]);
124 print_stacks(map_fd[0]);