1
2
3
4
5
6
7#include <errno.h>
8#include <fcntl.h>
9#include <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.h>
25#include <perf-sys.h>
26
27#include "main.h"
28
29#define MMAP_PAGE_CNT 16
30
31static volatile bool stop;
32
33struct event_ring_info {
34 int fd;
35 int key;
36 unsigned int cpu;
37 void *mem;
38};
39
40struct perf_event_sample {
41 struct perf_event_header header;
42 u64 time;
43 __u32 size;
44 unsigned char data[];
45};
46
47struct perf_event_lost {
48 struct perf_event_header header;
49 __u64 id;
50 __u64 lost;
51};
52
53static void int_exit(int signo)
54{
55 fprintf(stderr, "Stopping...\n");
56 stop = true;
57}
58
59struct event_pipe_ctx {
60 bool all_cpus;
61 int cpu;
62 int idx;
63};
64
65static enum bpf_perf_event_ret
66print_bpf_output(void *private_data, int cpu, struct perf_event_header *event)
67{
68 struct perf_event_sample *e = container_of(event,
69 struct perf_event_sample,
70 header);
71 struct perf_event_lost *lost = container_of(event,
72 struct perf_event_lost,
73 header);
74 struct event_pipe_ctx *ctx = private_data;
75 int idx = ctx->all_cpus ? cpu : ctx->idx;
76
77 if (json_output) {
78 jsonw_start_object(json_wtr);
79 jsonw_name(json_wtr, "type");
80 jsonw_uint(json_wtr, e->header.type);
81 jsonw_name(json_wtr, "cpu");
82 jsonw_uint(json_wtr, cpu);
83 jsonw_name(json_wtr, "index");
84 jsonw_uint(json_wtr, idx);
85 if (e->header.type == PERF_RECORD_SAMPLE) {
86 jsonw_name(json_wtr, "timestamp");
87 jsonw_uint(json_wtr, e->time);
88 jsonw_name(json_wtr, "data");
89 print_data_json(e->data, e->size);
90 } else if (e->header.type == PERF_RECORD_LOST) {
91 jsonw_name(json_wtr, "lost");
92 jsonw_start_object(json_wtr);
93 jsonw_name(json_wtr, "id");
94 jsonw_uint(json_wtr, lost->id);
95 jsonw_name(json_wtr, "count");
96 jsonw_uint(json_wtr, lost->lost);
97 jsonw_end_object(json_wtr);
98 }
99 jsonw_end_object(json_wtr);
100 } else {
101 if (e->header.type == PERF_RECORD_SAMPLE) {
102 printf("== @%lld.%09lld CPU: %d index: %d =====\n",
103 e->time / 1000000000ULL, e->time % 1000000000ULL,
104 cpu, idx);
105 fprint_hex(stdout, e->data, e->size, " ");
106 printf("\n");
107 } else if (e->header.type == PERF_RECORD_LOST) {
108 printf("lost %lld events\n", lost->lost);
109 } else {
110 printf("unknown event type=%d size=%d\n",
111 e->header.type, e->header.size);
112 }
113 }
114
115 return LIBBPF_PERF_EVENT_CONT;
116}
117
118int do_event_pipe(int argc, char **argv)
119{
120 struct perf_event_attr perf_attr = {
121 .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
122 .type = PERF_TYPE_SOFTWARE,
123 .config = PERF_COUNT_SW_BPF_OUTPUT,
124 .sample_period = 1,
125 .wakeup_events = 1,
126 };
127 struct bpf_map_info map_info = {};
128 struct perf_buffer_raw_opts opts = {};
129 struct event_pipe_ctx ctx = {
130 .all_cpus = true,
131 .cpu = -1,
132 .idx = -1,
133 };
134 struct perf_buffer *pb;
135 __u32 map_info_len;
136 int err, map_fd;
137
138 map_info_len = sizeof(map_info);
139 map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
140 if (map_fd < 0)
141 return -1;
142
143 if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
144 p_err("map is not a perf event array");
145 goto err_close_map;
146 }
147
148 while (argc) {
149 if (argc < 2) {
150 BAD_ARG();
151 goto err_close_map;
152 }
153
154 if (is_prefix(*argv, "cpu")) {
155 char *endptr;
156
157 NEXT_ARG();
158 ctx.cpu = strtoul(*argv, &endptr, 0);
159 if (*endptr) {
160 p_err("can't parse %s as CPU ID", **argv);
161 goto err_close_map;
162 }
163
164 NEXT_ARG();
165 } else if (is_prefix(*argv, "index")) {
166 char *endptr;
167
168 NEXT_ARG();
169 ctx.idx = strtoul(*argv, &endptr, 0);
170 if (*endptr) {
171 p_err("can't parse %s as index", **argv);
172 goto err_close_map;
173 }
174
175 NEXT_ARG();
176 } else {
177 BAD_ARG();
178 goto err_close_map;
179 }
180
181 ctx.all_cpus = false;
182 }
183
184 if (!ctx.all_cpus) {
185 if (ctx.idx == -1 || ctx.cpu == -1) {
186 p_err("cpu and index must be specified together");
187 goto err_close_map;
188 }
189 } else {
190 ctx.cpu = 0;
191 ctx.idx = 0;
192 }
193
194 opts.attr = &perf_attr;
195 opts.event_cb = print_bpf_output;
196 opts.ctx = &ctx;
197 opts.cpu_cnt = ctx.all_cpus ? 0 : 1;
198 opts.cpus = &ctx.cpu;
199 opts.map_keys = &ctx.idx;
200
201 pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &opts);
202 err = libbpf_get_error(pb);
203 if (err) {
204 p_err("failed to create perf buffer: %s (%d)",
205 strerror(err), err);
206 goto err_close_map;
207 }
208
209 signal(SIGINT, int_exit);
210 signal(SIGHUP, int_exit);
211 signal(SIGTERM, int_exit);
212
213 if (json_output)
214 jsonw_start_array(json_wtr);
215
216 while (!stop) {
217 err = perf_buffer__poll(pb, 200);
218 if (err < 0 && err != -EINTR) {
219 p_err("perf buffer polling failed: %s (%d)",
220 strerror(err), err);
221 goto err_close_pb;
222 }
223 }
224
225 if (json_output)
226 jsonw_end_array(json_wtr);
227
228 perf_buffer__free(pb);
229 close(map_fd);
230
231 return 0;
232
233err_close_pb:
234 perf_buffer__free(pb);
235err_close_map:
236 close(map_fd);
237 return -1;
238}
239
