/* 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 <signal.h>
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#include <linux/bpf.h>
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#include <string.h>
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#include <linux/perf_event.h>
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#include <errno.h>
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#include <assert.h>
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#include <stdbool.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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#include "trace_helpers.h"
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#define PRINT_RAW_ADDR 0
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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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if (PRINT_RAW_ADDR)
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printf("%s/%llx;", sym->name, addr);
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else
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printf("%s;", sym->name);
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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 waker[TASK_COMM_LEN];
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char target[TASK_COMM_LEN];
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__u32 wret;
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__u32 tret;
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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("%s;", key->target);
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if (bpf_map_lookup_elem(map_fd[3], &key->tret, 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_map_lookup_elem(map_fd[3], &key->wret, ip) != 0) {
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printf("---;");
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} else {
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for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
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print_ksym(ip[i]);
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}
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printf(";%s %lld\n", key->waker, count);
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if ((key->tret == -EEXIST || key->wret == -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->tret) < 0 || (int)(key->wret) < 0)) {
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printf("err stackid %d %d\n", key->tret, key->wret);
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}
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}
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static void print_stacks(int fd)
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{
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struct key_t key = {}, next_key;
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__u64 value;
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while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
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bpf_map_lookup_elem(fd, &next_key, &value);
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print_stack(&next_key, value);
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key = next_key;
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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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print_stacks(map_fd[0]);
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exit(0);
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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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int delay = 1;
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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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signal(SIGTERM, 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 2;
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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 1;
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}
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if (argc > 1)
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delay = atoi(argv[1]);
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sleep(delay);
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print_stacks(map_fd[0]);
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return 0;
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}
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