1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2018 Netronome Systems, Inc. */
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.
6 */
7 #include <errno.h>
8 #include <fcntl.h>
9 #include <bpf/libbpf.h>
10 #include <poll.h>
11 #include <signal.h>
12 #include <stdbool.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <time.h>
17 #include <unistd.h>
18 #include <linux/bpf.h>
19 #include <linux/perf_event.h>
20 #include <sys/ioctl.h>
21 #include <sys/mman.h>
22 #include <sys/syscall.h>
23
24 #include <bpf/bpf.h>
25
26 #include "main.h"
27
28 #define MMAP_PAGE_CNT 16
29
30 static volatile bool stop;
31
32 struct perf_event_sample {
33 struct perf_event_header header;
34 __u64 time;
35 __u32 size;
36 unsigned char data[];
37 };
38
39 struct perf_event_lost {
40 struct perf_event_header header;
41 __u64 id;
42 __u64 lost;
43 };
44
int_exit(int signo)45 static void int_exit(int signo)
46 {
47 fprintf(stderr, "Stopping...\n");
48 stop = true;
49 }
50
51 struct event_pipe_ctx {
52 bool all_cpus;
53 int cpu;
54 int idx;
55 };
56
57 static enum bpf_perf_event_ret
print_bpf_output(void * private_data,int cpu,struct perf_event_header * event)58 print_bpf_output(void *private_data, int cpu, struct perf_event_header *event)
59 {
60 struct perf_event_sample *e = container_of(event,
61 struct perf_event_sample,
62 header);
63 struct perf_event_lost *lost = container_of(event,
64 struct perf_event_lost,
65 header);
66 struct event_pipe_ctx *ctx = private_data;
67 int idx = ctx->all_cpus ? cpu : ctx->idx;
68
69 if (json_output) {
70 jsonw_start_object(json_wtr);
71 jsonw_name(json_wtr, "type");
72 jsonw_uint(json_wtr, e->header.type);
73 jsonw_name(json_wtr, "cpu");
74 jsonw_uint(json_wtr, cpu);
75 jsonw_name(json_wtr, "index");
76 jsonw_uint(json_wtr, idx);
77 if (e->header.type == PERF_RECORD_SAMPLE) {
78 jsonw_name(json_wtr, "timestamp");
79 jsonw_uint(json_wtr, e->time);
80 jsonw_name(json_wtr, "data");
81 print_data_json(e->data, e->size);
82 } else if (e->header.type == PERF_RECORD_LOST) {
83 jsonw_name(json_wtr, "lost");
84 jsonw_start_object(json_wtr);
85 jsonw_name(json_wtr, "id");
86 jsonw_uint(json_wtr, lost->id);
87 jsonw_name(json_wtr, "count");
88 jsonw_uint(json_wtr, lost->lost);
89 jsonw_end_object(json_wtr);
90 }
91 jsonw_end_object(json_wtr);
92 } else {
93 if (e->header.type == PERF_RECORD_SAMPLE) {
94 printf("== @%lld.%09lld CPU: %d index: %d =====\n",
95 e->time / 1000000000ULL, e->time % 1000000000ULL,
96 cpu, idx);
97 fprint_hex(stdout, e->data, e->size, " ");
98 printf("\n");
99 } else if (e->header.type == PERF_RECORD_LOST) {
100 printf("lost %lld events\n", lost->lost);
101 } else {
102 printf("unknown event type=%d size=%d\n",
103 e->header.type, e->header.size);
104 }
105 }
106
107 return LIBBPF_PERF_EVENT_CONT;
108 }
109
do_event_pipe(int argc,char ** argv)110 int do_event_pipe(int argc, char **argv)
111 {
112 struct perf_event_attr perf_attr = {
113 .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
114 .type = PERF_TYPE_SOFTWARE,
115 .config = PERF_COUNT_SW_BPF_OUTPUT,
116 .sample_period = 1,
117 .wakeup_events = 1,
118 };
119 struct bpf_map_info map_info = {};
120 LIBBPF_OPTS(perf_buffer_raw_opts, opts);
121 struct event_pipe_ctx ctx = {
122 .all_cpus = true,
123 .cpu = -1,
124 .idx = -1,
125 };
126 struct perf_buffer *pb;
127 __u32 map_info_len;
128 int err, map_fd;
129
130 map_info_len = sizeof(map_info);
131 map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
132 if (map_fd < 0)
133 return -1;
134
135 if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
136 p_err("map is not a perf event array");
137 goto err_close_map;
138 }
139
140 while (argc) {
141 if (argc < 2) {
142 BAD_ARG();
143 goto err_close_map;
144 }
145
146 if (is_prefix(*argv, "cpu")) {
147 char *endptr;
148
149 NEXT_ARG();
150 ctx.cpu = strtoul(*argv, &endptr, 0);
151 if (*endptr) {
152 p_err("can't parse %s as CPU ID", *argv);
153 goto err_close_map;
154 }
155
156 NEXT_ARG();
157 } else if (is_prefix(*argv, "index")) {
158 char *endptr;
159
160 NEXT_ARG();
161 ctx.idx = strtoul(*argv, &endptr, 0);
162 if (*endptr) {
163 p_err("can't parse %s as index", *argv);
164 goto err_close_map;
165 }
166
167 NEXT_ARG();
168 } else {
169 BAD_ARG();
170 goto err_close_map;
171 }
172
173 ctx.all_cpus = false;
174 }
175
176 if (!ctx.all_cpus) {
177 if (ctx.idx == -1 || ctx.cpu == -1) {
178 p_err("cpu and index must be specified together");
179 goto err_close_map;
180 }
181 } else {
182 ctx.cpu = 0;
183 ctx.idx = 0;
184 }
185
186 opts.cpu_cnt = ctx.all_cpus ? 0 : 1;
187 opts.cpus = &ctx.cpu;
188 opts.map_keys = &ctx.idx;
189 pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &perf_attr,
190 print_bpf_output, &ctx, &opts);
191 if (!pb) {
192 p_err("failed to create perf buffer: %s (%d)",
193 strerror(errno), errno);
194 goto err_close_map;
195 }
196
197 signal(SIGINT, int_exit);
198 signal(SIGHUP, int_exit);
199 signal(SIGTERM, int_exit);
200
201 if (json_output)
202 jsonw_start_array(json_wtr);
203
204 while (!stop) {
205 err = perf_buffer__poll(pb, 200);
206 if (err < 0 && err != -EINTR) {
207 p_err("perf buffer polling failed: %s (%d)",
208 strerror(errno), errno);
209 goto err_close_pb;
210 }
211 }
212
213 if (json_output)
214 jsonw_end_array(json_wtr);
215
216 perf_buffer__free(pb);
217 close(map_fd);
218
219 return 0;
220
221 err_close_pb:
222 perf_buffer__free(pb);
223 err_close_map:
224 close(map_fd);
225 return -1;
226 }
227