1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* Copyright (c) 2016 Facebook |
3 | */ |
4 | #include <stdio.h> |
5 | #include <unistd.h> |
6 | #include <stdlib.h> |
7 | #include <signal.h> |
8 | #include <linux/perf_event.h> |
9 | #include <errno.h> |
10 | #include <stdbool.h> |
11 | #include <bpf/libbpf.h> |
12 | #include <bpf/bpf.h> |
13 | #include "trace_helpers.h" |
14 | |
15 | #define PRINT_RAW_ADDR 0 |
16 | |
17 | /* counts, stackmap */ |
18 | static int map_fd[2]; |
19 | |
20 | static void print_ksym(__u64 addr) |
21 | { |
22 | struct ksym *sym; |
23 | |
24 | if (!addr) |
25 | return; |
26 | sym = ksym_search(addr); |
27 | if (!sym) { |
28 | printf(format: "ksym not found. Is kallsyms loaded?\n" ); |
29 | return; |
30 | } |
31 | |
32 | if (PRINT_RAW_ADDR) |
33 | printf(format: "%s/%llx;" , sym->name, addr); |
34 | else |
35 | printf(format: "%s;" , sym->name); |
36 | } |
37 | |
38 | #define TASK_COMM_LEN 16 |
39 | |
40 | struct key_t { |
41 | char waker[TASK_COMM_LEN]; |
42 | char target[TASK_COMM_LEN]; |
43 | __u32 wret; |
44 | __u32 tret; |
45 | }; |
46 | |
47 | static void print_stack(struct key_t *key, __u64 count) |
48 | { |
49 | __u64 ip[PERF_MAX_STACK_DEPTH] = {}; |
50 | static bool warned; |
51 | int i; |
52 | |
53 | printf(format: "%s;" , key->target); |
54 | if (bpf_map_lookup_elem(map_fd[1], &key->tret, ip) != 0) { |
55 | printf(format: "---;" ); |
56 | } else { |
57 | for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--) |
58 | print_ksym(addr: ip[i]); |
59 | } |
60 | printf(format: "-;" ); |
61 | if (bpf_map_lookup_elem(map_fd[1], &key->wret, ip) != 0) { |
62 | printf(format: "---;" ); |
63 | } else { |
64 | for (i = 0; i < PERF_MAX_STACK_DEPTH; i++) |
65 | print_ksym(addr: ip[i]); |
66 | } |
67 | printf(format: ";%s %lld\n" , key->waker, count); |
68 | |
69 | if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) { |
70 | printf(format: "stackmap collisions seen. Consider increasing size\n" ); |
71 | warned = true; |
72 | } else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) { |
73 | printf(format: "err stackid %d %d\n" , key->tret, key->wret); |
74 | } |
75 | } |
76 | |
77 | static void print_stacks(int fd) |
78 | { |
79 | struct key_t key = {}, next_key; |
80 | __u64 value; |
81 | |
82 | while (bpf_map_get_next_key(fd, &key, &next_key) == 0) { |
83 | bpf_map_lookup_elem(fd, &next_key, &value); |
84 | print_stack(key: &next_key, count: value); |
85 | key = next_key; |
86 | } |
87 | } |
88 | |
89 | static void int_exit(int sig) |
90 | { |
91 | print_stacks(fd: map_fd[0]); |
92 | exit(status: 0); |
93 | } |
94 | |
95 | int main(int argc, char **argv) |
96 | { |
97 | struct bpf_object *obj = NULL; |
98 | struct bpf_link *links[2]; |
99 | struct bpf_program *prog; |
100 | int delay = 1, i = 0; |
101 | char filename[256]; |
102 | |
103 | if (load_kallsyms()) { |
104 | printf(format: "failed to process /proc/kallsyms\n" ); |
105 | return 2; |
106 | } |
107 | |
108 | snprintf(s: filename, maxlen: sizeof(filename), format: "%s.bpf.o" , argv[0]); |
109 | obj = bpf_object__open_file(filename, NULL); |
110 | if (libbpf_get_error(obj)) { |
111 | fprintf(stderr, format: "ERROR: opening BPF object file failed\n" ); |
112 | obj = NULL; |
113 | goto cleanup; |
114 | } |
115 | |
116 | /* load BPF program */ |
117 | if (bpf_object__load(obj)) { |
118 | fprintf(stderr, format: "ERROR: loading BPF object file failed\n" ); |
119 | goto cleanup; |
120 | } |
121 | |
122 | map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts" ); |
123 | map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap" ); |
124 | if (map_fd[0] < 0 || map_fd[1] < 0) { |
125 | fprintf(stderr, format: "ERROR: finding a map in obj file failed\n" ); |
126 | goto cleanup; |
127 | } |
128 | |
129 | signal(SIGINT, handler: int_exit); |
130 | signal(SIGTERM, handler: int_exit); |
131 | |
132 | bpf_object__for_each_program(prog, obj) { |
133 | links[i] = bpf_program__attach(prog); |
134 | if (libbpf_get_error(links[i])) { |
135 | fprintf(stderr, format: "ERROR: bpf_program__attach failed\n" ); |
136 | links[i] = NULL; |
137 | goto cleanup; |
138 | } |
139 | i++; |
140 | } |
141 | |
142 | if (argc > 1) |
143 | delay = atoi(nptr: argv[1]); |
144 | sleep(seconds: delay); |
145 | print_stacks(fd: map_fd[0]); |
146 | |
147 | cleanup: |
148 | for (i--; i >= 0; i--) |
149 | bpf_link__destroy(links[i]); |
150 | |
151 | bpf_object__close(obj); |
152 | return 0; |
153 | } |
154 | |