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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * JSON export.
4 *
5 * Copyright (C) 2021, CodeWeavers Inc. <nfraser@codeweavers.com>
6 */
7
8#include "data-convert.h"
9
10#include <fcntl.h>
11#include <inttypes.h>
12#include <sys/stat.h>
13#include <unistd.h>
14
15#include "linux/compiler.h"
16#include "linux/err.h"
17#include "util/auxtrace.h"
18#include "util/debug.h"
19#include "util/dso.h"
20#include "util/event.h"
21#include "util/evsel.h"
22#include "util/evlist.h"
23#include "util/header.h"
24#include "util/map.h"
25#include "util/session.h"
26#include "util/symbol.h"
27#include "util/thread.h"
28#include "util/tool.h"
29
30#ifdef HAVE_LIBTRACEEVENT
31#include <traceevent/event-parse.h>
32#endif
33
34struct convert_json {
35 struct perf_tool tool;
36 FILE *out;
37 bool first;
38 u64 events_count;
39};
40
41// Outputs a JSON-encoded string surrounded by quotes with characters escaped.
42static void output_json_string(FILE *out, const char *s)
43{
44 fputc('"', out);
45 while (*s) {
46 switch (*s) {
47
48 // required escapes with special forms as per RFC 8259
49 case '"': fputs("\\\"", out); break;
50 case '\\': fputs("\\\\", out); break;
51 case '\b': fputs("\\b", out); break;
52 case '\f': fputs("\\f", out); break;
53 case '\n': fputs("\\n", out); break;
54 case '\r': fputs("\\r", out); break;
55 case '\t': fputs("\\t", out); break;
56
57 default:
58 // all other control characters must be escaped by hex code
59 if (*s <= 0x1f)
60 fprintf(out, "\\u%04x", *s);
61 else
62 fputc(*s, out);
63 break;
64 }
65
66 ++s;
67 }
68 fputc('"', out);
69}
70
71// Outputs an optional comma, newline and indentation to delimit a new value
72// from the previous one in a JSON object or array.
73static void output_json_delimiters(FILE *out, bool comma, int depth)
74{
75 int i;
76
77 if (comma)
78 fputc(',', out);
79 fputc('\n', out);
80 for (i = 0; i < depth; ++i)
81 fputc('\t', out);
82}
83
84// Outputs a printf format string (with delimiter) as a JSON value.
85__printf(4, 5)
86static void output_json_format(FILE *out, bool comma, int depth, const char *format, ...)
87{
88 va_list args;
89
90 output_json_delimiters(out, comma, depth);
91 va_start(args, format);
92 vfprintf(out, format, args);
93 va_end(args);
94}
95
96// Outputs a JSON key-value pair where the value is a string.
97static void output_json_key_string(FILE *out, bool comma, int depth,
98 const char *key, const char *value)
99{
100 output_json_delimiters(out, comma, depth);
101 output_json_string(out, key);
102 fputs(": ", out);
103 output_json_string(out, value);
104}
105
106// Outputs a JSON key-value pair where the value is a printf format string.
107__printf(5, 6)
108static void output_json_key_format(FILE *out, bool comma, int depth,
109 const char *key, const char *format, ...)
110{
111 va_list args;
112
113 output_json_delimiters(out, comma, depth);
114 output_json_string(out, key);
115 fputs(": ", out);
116 va_start(args, format);
117 vfprintf(out, format, args);
118 va_end(args);
119}
120
121static void output_sample_callchain_entry(struct perf_tool *tool,
122 u64 ip, struct addr_location *al)
123{
124 struct convert_json *c = container_of(tool, struct convert_json, tool);
125 FILE *out = c->out;
126
127 output_json_format(out, false, 4, "{");
128 output_json_key_format(out, false, 5, "ip", "\"0x%" PRIx64 "\"", ip);
129
130 if (al && al->sym && al->sym->namelen) {
131 fputc(',', out);
132 output_json_key_string(out, false, 5, "symbol", al->sym->name);
133
134 if (al->map && al->map->dso) {
135 const char *dso = al->map->dso->short_name;
136
137 if (dso && strlen(dso) > 0) {
138 fputc(',', out);
139 output_json_key_string(out, false, 5, "dso", dso);
140 }
141 }
142 }
143
144 output_json_format(out, false, 4, "}");
145}
146
147static int process_sample_event(struct perf_tool *tool,
148 union perf_event *event __maybe_unused,
149 struct perf_sample *sample,
150 struct evsel *evsel __maybe_unused,
151 struct machine *machine)
152{
153 struct convert_json *c = container_of(tool, struct convert_json, tool);
154 FILE *out = c->out;
155 struct addr_location al, tal;
156 u64 sample_type = __evlist__combined_sample_type(evsel->evlist);
157 u8 cpumode = PERF_RECORD_MISC_USER;
158
159 if (machine__resolve(machine, &al, sample) < 0) {
160 pr_err("Sample resolution failed!\n");
161 return -1;
162 }
163
164 ++c->events_count;
165
166 if (c->first)
167 c->first = false;
168 else
169 fputc(',', out);
170 output_json_format(out, false, 2, "{");
171
172 output_json_key_format(out, false, 3, "timestamp", "%" PRIi64, sample->time);
173 output_json_key_format(out, true, 3, "pid", "%i", al.thread->pid_);
174 output_json_key_format(out, true, 3, "tid", "%i", al.thread->tid);
175
176 if ((sample_type & PERF_SAMPLE_CPU))
177 output_json_key_format(out, true, 3, "cpu", "%i", sample->cpu);
178 else if (al.thread->cpu >= 0)
179 output_json_key_format(out, true, 3, "cpu", "%i", al.thread->cpu);
180
181 output_json_key_string(out, true, 3, "comm", thread__comm_str(al.thread));
182
183 output_json_key_format(out, true, 3, "callchain", "[");
184 if (sample->callchain) {
185 unsigned int i;
186 bool ok;
187 bool first_callchain = true;
188
189 for (i = 0; i < sample->callchain->nr; ++i) {
190 u64 ip = sample->callchain->ips[i];
191
192 if (ip >= PERF_CONTEXT_MAX) {
193 switch (ip) {
194 case PERF_CONTEXT_HV:
195 cpumode = PERF_RECORD_MISC_HYPERVISOR;
196 break;
197 case PERF_CONTEXT_KERNEL:
198 cpumode = PERF_RECORD_MISC_KERNEL;
199 break;
200 case PERF_CONTEXT_USER:
201 cpumode = PERF_RECORD_MISC_USER;
202 break;
203 default:
204 pr_debug("invalid callchain context: %"
205 PRId64 "\n", (s64) ip);
206 break;
207 }
208 continue;
209 }
210
211 if (first_callchain)
212 first_callchain = false;
213 else
214 fputc(',', out);
215
216 ok = thread__find_symbol(al.thread, cpumode, ip, &tal);
217 output_sample_callchain_entry(tool, ip, ok ? &tal : NULL);
218 }
219 } else {
220 output_sample_callchain_entry(tool, sample->ip, &al);
221 }
222 output_json_format(out, false, 3, "]");
223
224#ifdef HAVE_LIBTRACEEVENT
225 if (sample->raw_data) {
226 int i;
227 struct tep_format_field **fields;
228
229 fields = tep_event_fields(evsel->tp_format);
230 if (fields) {
231 i = 0;
232 while (fields[i]) {
233 struct trace_seq s;
234
235 trace_seq_init(&s);
236 tep_print_field(&s, sample->raw_data, fields[i]);
237 output_json_key_string(out, true, 3, fields[i]->name, s.buffer);
238
239 i++;
240 }
241 free(fields);
242 }
243 }
244#endif
245 output_json_format(out, false, 2, "}");
246 return 0;
247}
248
249static void output_headers(struct perf_session *session, struct convert_json *c)
250{
251 struct stat st;
252 struct perf_header *header = &session->header;
253 int ret;
254 int fd = perf_data__fd(session->data);
255 int i;
256 FILE *out = c->out;
257
258 output_json_key_format(out, false, 2, "header-version", "%u", header->version);
259
260 ret = fstat(fd, &st);
261 if (ret >= 0) {
262 time_t stctime = st.st_mtime;
263 char buf[256];
264
265 strftime(buf, sizeof(buf), "%FT%TZ", gmtime(&stctime));
266 output_json_key_string(out, true, 2, "captured-on", buf);
267 } else {
268 pr_debug("Failed to get mtime of source file, not writing captured-on");
269 }
270
271 output_json_key_format(out, true, 2, "data-offset", "%" PRIu64, header->data_offset);
272 output_json_key_format(out, true, 2, "data-size", "%" PRIu64, header->data_size);
273 output_json_key_format(out, true, 2, "feat-offset", "%" PRIu64, header->feat_offset);
274
275 output_json_key_string(out, true, 2, "hostname", header->env.hostname);
276 output_json_key_string(out, true, 2, "os-release", header->env.os_release);
277 output_json_key_string(out, true, 2, "arch", header->env.arch);
278
279 output_json_key_string(out, true, 2, "cpu-desc", header->env.cpu_desc);
280 output_json_key_string(out, true, 2, "cpuid", header->env.cpuid);
281 output_json_key_format(out, true, 2, "nrcpus-online", "%u", header->env.nr_cpus_online);
282 output_json_key_format(out, true, 2, "nrcpus-avail", "%u", header->env.nr_cpus_avail);
283
284 if (header->env.clock.enabled) {
285 output_json_key_format(out, true, 2, "clockid",
286 "%u", header->env.clock.clockid);
287 output_json_key_format(out, true, 2, "clock-time",
288 "%" PRIu64, header->env.clock.clockid_ns);
289 output_json_key_format(out, true, 2, "real-time",
290 "%" PRIu64, header->env.clock.tod_ns);
291 }
292
293 output_json_key_string(out, true, 2, "perf-version", header->env.version);
294
295 output_json_key_format(out, true, 2, "cmdline", "[");
296 for (i = 0; i < header->env.nr_cmdline; i++) {
297 output_json_delimiters(out, i != 0, 3);
298 output_json_string(c->out, header->env.cmdline_argv[i]);
299 }
300 output_json_format(out, false, 2, "]");
301}
302
303int bt_convert__perf2json(const char *input_name, const char *output_name,
304 struct perf_data_convert_opts *opts __maybe_unused)
305{
306 struct perf_session *session;
307 int fd;
308 int ret = -1;
309
310 struct convert_json c = {
311 .tool = {
312 .sample = process_sample_event,
313 .mmap = perf_event__process_mmap,
314 .mmap2 = perf_event__process_mmap2,
315 .comm = perf_event__process_comm,
316 .namespaces = perf_event__process_namespaces,
317 .cgroup = perf_event__process_cgroup,
318 .exit = perf_event__process_exit,
319 .fork = perf_event__process_fork,
320 .lost = perf_event__process_lost,
321#ifdef HAVE_LIBTRACEEVENT
322 .tracing_data = perf_event__process_tracing_data,
323#endif
324 .build_id = perf_event__process_build_id,
325 .id_index = perf_event__process_id_index,
326 .auxtrace_info = perf_event__process_auxtrace_info,
327 .auxtrace = perf_event__process_auxtrace,
328 .event_update = perf_event__process_event_update,
329 .ordered_events = true,
330 .ordering_requires_timestamps = true,
331 },
332 .first = true,
333 .events_count = 0,
334 };
335
336 struct perf_data data = {
337 .mode = PERF_DATA_MODE_READ,
338 .path = input_name,
339 .force = opts->force,
340 };
341
342 if (opts->all) {
343 pr_err("--all is currently unsupported for JSON output.\n");
344 goto err;
345 }
346 if (opts->tod) {
347 pr_err("--tod is currently unsupported for JSON output.\n");
348 goto err;
349 }
350
351 fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666);
352 if (fd == -1) {
353 if (errno == EEXIST)
354 pr_err("Output file exists. Use --force to overwrite it.\n");
355 else
356 pr_err("Error opening output file!\n");
357 goto err;
358 }
359
360 c.out = fdopen(fd, "w");
361 if (!c.out) {
362 fprintf(stderr, "Error opening output file!\n");
363 close(fd);
364 goto err;
365 }
366
367 session = perf_session__new(&data, &c.tool);
368 if (IS_ERR(session)) {
369 fprintf(stderr, "Error creating perf session!\n");
370 goto err_fclose;
371 }
372
373 if (symbol__init(&session->header.env) < 0) {
374 fprintf(stderr, "Symbol init error!\n");
375 goto err_session_delete;
376 }
377
378 // The opening brace is printed manually because it isn't delimited from a
379 // previous value (i.e. we don't want a leading newline)
380 fputc('{', c.out);
381
382 // Version number for future-proofing. Most additions should be able to be
383 // done in a backwards-compatible way so this should only need to be bumped
384 // if some major breaking change must be made.
385 output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1");
386
387 // Output headers
388 output_json_format(c.out, true, 1, "\"headers\": {");
389 output_headers(session, &c);
390 output_json_format(c.out, false, 1, "}");
391
392 // Output samples
393 output_json_format(c.out, true, 1, "\"samples\": [");
394 perf_session__process_events(session);
395 output_json_format(c.out, false, 1, "]");
396 output_json_format(c.out, false, 0, "}");
397 fputc('\n', c.out);
398
399 fprintf(stderr,
400 "[ perf data convert: Converted '%s' into JSON data '%s' ]\n",
401 data.path, output_name);
402
403 fprintf(stderr,
404 "[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n",
405 (ftell(c.out)) / 1024.0 / 1024.0, c.events_count);
406
407 ret = 0;
408err_session_delete:
409 perf_session__delete(session);
410err_fclose:
411 fclose(c.out);
412err:
413 return ret;
414}