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/time-utils.h"
29 #include "util/tool.h"
30
31 #ifdef HAVE_LIBTRACEEVENT
32 #include <event-parse.h>
33 #endif
34
35 struct convert_json {
36 struct perf_tool tool;
37 FILE *out;
38 bool first;
39 struct perf_time_interval *ptime_range;
40 int range_size;
41 int range_num;
42
43 u64 events_count;
44 u64 skipped;
45 };
46
47 // Outputs a JSON-encoded string surrounded by quotes with characters escaped.
output_json_string(FILE * out,const char * s)48 static void output_json_string(FILE *out, const char *s)
49 {
50 fputc('"', out);
51 if (!s)
52 goto out;
53
54 while (*s) {
55 switch (*s) {
56
57 // required escapes with special forms as per RFC 8259
58 case '"': fputs("\\\"", out); break;
59 case '\\': fputs("\\\\", out); break;
60 case '\b': fputs("\\b", out); break;
61 case '\f': fputs("\\f", out); break;
62 case '\n': fputs("\\n", out); break;
63 case '\r': fputs("\\r", out); break;
64 case '\t': fputs("\\t", out); break;
65
66 default:
67 // all other control characters must be escaped by hex code
68 if (*s <= 0x1f)
69 fprintf(out, "\\u%04x", *s);
70 else
71 fputc(*s, out);
72 break;
73 }
74
75 ++s;
76 }
77 out:
78 fputc('"', out);
79 }
80
81 // Outputs an optional comma, newline and indentation to delimit a new value
82 // from the previous one in a JSON object or array.
output_json_delimiters(FILE * out,bool comma,int depth)83 static void output_json_delimiters(FILE *out, bool comma, int depth)
84 {
85 int i;
86
87 if (comma)
88 fputc(',', out);
89 fputc('\n', out);
90 for (i = 0; i < depth; ++i)
91 fputc('\t', out);
92 }
93
94 // Outputs a printf format string (with delimiter) as a JSON value.
95 __printf(4, 5)
output_json_format(FILE * out,bool comma,int depth,const char * format,...)96 static void output_json_format(FILE *out, bool comma, int depth, const char *format, ...)
97 {
98 va_list args;
99
100 output_json_delimiters(out, comma, depth);
101 va_start(args, format);
102 vfprintf(out, format, args);
103 va_end(args);
104 }
105
106 // Outputs a JSON key-value pair where the value is a string.
output_json_key_string(FILE * out,bool comma,int depth,const char * key,const char * value)107 static void output_json_key_string(FILE *out, bool comma, int depth,
108 const char *key, const char *value)
109 {
110 output_json_delimiters(out, comma, depth);
111 output_json_string(out, key);
112 fputs(": ", out);
113 output_json_string(out, value);
114 }
115
116 // Outputs a JSON key-value pair where the value is a printf format string.
117 __printf(5, 6)
output_json_key_format(FILE * out,bool comma,int depth,const char * key,const char * format,...)118 static void output_json_key_format(FILE *out, bool comma, int depth,
119 const char *key, const char *format, ...)
120 {
121 va_list args;
122
123 output_json_delimiters(out, comma, depth);
124 output_json_string(out, key);
125 fputs(": ", out);
126 va_start(args, format);
127 vfprintf(out, format, args);
128 va_end(args);
129 }
130
output_sample_callchain_entry(const struct perf_tool * tool,u64 ip,struct addr_location * al)131 static void output_sample_callchain_entry(const struct perf_tool *tool,
132 u64 ip, struct addr_location *al)
133 {
134 struct convert_json *c = container_of(tool, struct convert_json, tool);
135 FILE *out = c->out;
136
137 output_json_format(out, false, 4, "{");
138 output_json_key_format(out, false, 5, "ip", "\"0x%" PRIx64 "\"", ip);
139
140 if (al && al->sym && al->sym->namelen) {
141 struct dso *dso = al->map ? map__dso(al->map) : NULL;
142
143 fputc(',', out);
144 output_json_key_string(out, false, 5, "symbol", al->sym->name);
145
146 if (dso) {
147 const char *dso_name = dso__short_name(dso);
148
149 if (dso_name && strlen(dso_name) > 0) {
150 fputc(',', out);
151 output_json_key_string(out, false, 5, "dso", dso_name);
152 }
153 }
154 }
155
156 output_json_format(out, false, 4, "}");
157 }
158
process_sample_event(const struct perf_tool * tool,union perf_event * event __maybe_unused,struct perf_sample * sample,struct evsel * evsel __maybe_unused,struct machine * machine)159 static int process_sample_event(const struct perf_tool *tool,
160 union perf_event *event __maybe_unused,
161 struct perf_sample *sample,
162 struct evsel *evsel __maybe_unused,
163 struct machine *machine)
164 {
165 struct convert_json *c = container_of(tool, struct convert_json, tool);
166 FILE *out = c->out;
167 struct addr_location al;
168 u64 sample_type = __evlist__combined_sample_type(evsel->evlist);
169 u8 cpumode = PERF_RECORD_MISC_USER;
170
171 addr_location__init(&al);
172 if (machine__resolve(machine, &al, sample) < 0) {
173 pr_err("Sample resolution failed!\n");
174 addr_location__exit(&al);
175 return -1;
176 }
177
178 if (perf_time__ranges_skip_sample(c->ptime_range, c->range_num, sample->time)) {
179 ++c->skipped;
180 return 0;
181 }
182
183 ++c->events_count;
184
185 if (c->first)
186 c->first = false;
187 else
188 fputc(',', out);
189 output_json_format(out, false, 2, "{");
190
191 output_json_key_format(out, false, 3, "timestamp", "%" PRIi64, sample->time);
192 output_json_key_format(out, true, 3, "pid", "%i", thread__pid(al.thread));
193 output_json_key_format(out, true, 3, "tid", "%i", thread__tid(al.thread));
194
195 if ((sample_type & PERF_SAMPLE_CPU))
196 output_json_key_format(out, true, 3, "cpu", "%i", sample->cpu);
197 else if (thread__cpu(al.thread) >= 0)
198 output_json_key_format(out, true, 3, "cpu", "%i", thread__cpu(al.thread));
199
200 output_json_key_string(out, true, 3, "comm", thread__comm_str(al.thread));
201
202 output_json_key_format(out, true, 3, "callchain", "[");
203 if (sample->callchain) {
204 unsigned int i;
205 bool ok;
206 bool first_callchain = true;
207
208 for (i = 0; i < sample->callchain->nr; ++i) {
209 u64 ip = sample->callchain->ips[i];
210 struct addr_location tal;
211
212 if (ip >= PERF_CONTEXT_MAX) {
213 switch (ip) {
214 case PERF_CONTEXT_HV:
215 cpumode = PERF_RECORD_MISC_HYPERVISOR;
216 break;
217 case PERF_CONTEXT_KERNEL:
218 cpumode = PERF_RECORD_MISC_KERNEL;
219 break;
220 case PERF_CONTEXT_USER:
221 cpumode = PERF_RECORD_MISC_USER;
222 break;
223 default:
224 pr_debug("invalid callchain context: %"
225 PRId64 "\n", (s64) ip);
226 break;
227 }
228 continue;
229 }
230
231 if (first_callchain)
232 first_callchain = false;
233 else
234 fputc(',', out);
235
236 addr_location__init(&tal);
237 ok = thread__find_symbol(al.thread, cpumode, ip, &tal);
238 output_sample_callchain_entry(tool, ip, ok ? &tal : NULL);
239 addr_location__exit(&tal);
240 }
241 } else {
242 output_sample_callchain_entry(tool, sample->ip, &al);
243 }
244 output_json_format(out, false, 3, "]");
245
246 #ifdef HAVE_LIBTRACEEVENT
247 if (sample->raw_data) {
248 struct tep_event *tp_format = evsel__tp_format(evsel);
249 struct tep_format_field **fields = tp_format ? tep_event_fields(tp_format) : NULL;
250
251 if (fields) {
252 int i = 0;
253
254 while (fields[i]) {
255 struct trace_seq s;
256
257 trace_seq_init(&s);
258 tep_print_field(&s, sample->raw_data, fields[i]);
259 output_json_key_string(out, true, 3, fields[i]->name, s.buffer);
260
261 i++;
262 }
263 free(fields);
264 }
265 }
266 #endif
267 output_json_format(out, false, 2, "}");
268 addr_location__exit(&al);
269 return 0;
270 }
271
output_headers(struct perf_session * session,struct convert_json * c)272 static void output_headers(struct perf_session *session, struct convert_json *c)
273 {
274 struct stat st;
275 const struct perf_header *header = &session->header;
276 const struct perf_env *env = perf_session__env(session);
277 int ret;
278 int fd = perf_data__fd(session->data);
279 int i;
280 FILE *out = c->out;
281
282 output_json_key_format(out, false, 2, "header-version", "%u", header->version);
283
284 ret = fstat(fd, &st);
285 if (ret >= 0) {
286 time_t stctime = st.st_mtime;
287 char buf[256];
288
289 strftime(buf, sizeof(buf), "%FT%TZ", gmtime(&stctime));
290 output_json_key_string(out, true, 2, "captured-on", buf);
291 } else {
292 pr_debug("Failed to get mtime of source file, not writing captured-on");
293 }
294
295 output_json_key_format(out, true, 2, "data-offset", "%" PRIu64, header->data_offset);
296 output_json_key_format(out, true, 2, "data-size", "%" PRIu64, header->data_size);
297 output_json_key_format(out, true, 2, "feat-offset", "%" PRIu64, header->feat_offset);
298
299 output_json_key_string(out, true, 2, "hostname", env->hostname);
300 output_json_key_string(out, true, 2, "os-release", env->os_release);
301 output_json_key_string(out, true, 2, "arch", env->arch);
302
303 if (env->cpu_desc)
304 output_json_key_string(out, true, 2, "cpu-desc", env->cpu_desc);
305
306 output_json_key_string(out, true, 2, "cpuid", env->cpuid);
307 output_json_key_format(out, true, 2, "nrcpus-online", "%u", env->nr_cpus_online);
308 output_json_key_format(out, true, 2, "nrcpus-avail", "%u", env->nr_cpus_avail);
309
310 if (env->clock.enabled) {
311 output_json_key_format(out, true, 2, "clockid",
312 "%u", env->clock.clockid);
313 output_json_key_format(out, true, 2, "clock-time",
314 "%" PRIu64, env->clock.clockid_ns);
315 output_json_key_format(out, true, 2, "real-time",
316 "%" PRIu64, env->clock.tod_ns);
317 }
318
319 output_json_key_string(out, true, 2, "perf-version", env->version);
320
321 output_json_key_format(out, true, 2, "cmdline", "[");
322 for (i = 0; i < env->nr_cmdline; i++) {
323 output_json_delimiters(out, i != 0, 3);
324 output_json_string(c->out, env->cmdline_argv[i]);
325 }
326 output_json_format(out, false, 2, "]");
327 }
328
process_feature_event(const struct perf_tool * tool __maybe_unused,struct perf_session * session,union perf_event * event)329 static int process_feature_event(const struct perf_tool *tool __maybe_unused,
330 struct perf_session *session,
331 union perf_event *event)
332 {
333 if (event->feat.feat_id < HEADER_LAST_FEATURE)
334 return perf_event__process_feature(session, event);
335
336 return 0;
337 }
338
bt_convert__perf2json(const char * input_name,const char * output_name,struct perf_data_convert_opts * opts __maybe_unused)339 int bt_convert__perf2json(const char *input_name, const char *output_name,
340 struct perf_data_convert_opts *opts __maybe_unused)
341 {
342 struct perf_session *session;
343 int fd;
344 int ret = -1;
345 struct convert_json c = {
346 .first = true,
347 .events_count = 0,
348 .ptime_range = NULL,
349 .range_size = 0,
350 .range_num = 0,
351 .skipped = 0,
352 };
353 struct perf_data data = {
354 .mode = PERF_DATA_MODE_READ,
355 .path = input_name,
356 .force = opts->force,
357 };
358
359 perf_tool__init(&c.tool, /*ordered_events=*/true);
360 c.tool.sample = process_sample_event;
361 c.tool.mmap = perf_event__process_mmap;
362 c.tool.mmap2 = perf_event__process_mmap2;
363 c.tool.comm = perf_event__process_comm;
364 c.tool.namespaces = perf_event__process_namespaces;
365 c.tool.cgroup = perf_event__process_cgroup;
366 c.tool.exit = perf_event__process_exit;
367 c.tool.fork = perf_event__process_fork;
368 c.tool.lost = perf_event__process_lost;
369 #ifdef HAVE_LIBTRACEEVENT
370 c.tool.tracing_data = perf_event__process_tracing_data;
371 #endif
372 c.tool.build_id = perf_event__process_build_id;
373 c.tool.id_index = perf_event__process_id_index;
374 c.tool.auxtrace_info = perf_event__process_auxtrace_info;
375 c.tool.auxtrace = perf_event__process_auxtrace;
376 c.tool.event_update = perf_event__process_event_update;
377 c.tool.attr = perf_event__process_attr;
378 c.tool.feature = process_feature_event;
379 c.tool.ordering_requires_timestamps = true;
380
381 if (opts->all) {
382 pr_err("--all is currently unsupported for JSON output.\n");
383 goto err;
384 }
385 if (opts->tod) {
386 pr_err("--tod is currently unsupported for JSON output.\n");
387 goto err;
388 }
389
390 fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666);
391 if (fd == -1) {
392 if (errno == EEXIST)
393 pr_err("Output file exists. Use --force to overwrite it.\n");
394 else
395 pr_err("Error opening output file!\n");
396 goto err;
397 }
398
399 c.out = fdopen(fd, "w");
400 if (!c.out) {
401 fprintf(stderr, "Error opening output file!\n");
402 close(fd);
403 goto err;
404 }
405
406 session = perf_session__new(&data, &c.tool);
407 if (IS_ERR(session)) {
408 fprintf(stderr, "Error creating perf session!\n");
409 goto err_fclose;
410 }
411 if (symbol__init(perf_session__env(session)) < 0) {
412 fprintf(stderr, "Symbol init error!\n");
413 goto err_session_delete;
414 }
415
416 if (opts->time_str) {
417 ret = perf_time__parse_for_ranges(opts->time_str, session,
418 &c.ptime_range,
419 &c.range_size,
420 &c.range_num);
421 if (ret < 0)
422 goto err_session_delete;
423 }
424
425 // The opening brace is printed manually because it isn't delimited from a
426 // previous value (i.e. we don't want a leading newline)
427 fputc('{', c.out);
428
429 // Version number for future-proofing. Most additions should be able to be
430 // done in a backwards-compatible way so this should only need to be bumped
431 // if some major breaking change must be made.
432 output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1");
433
434 // Output headers
435 output_json_format(c.out, true, 1, "\"headers\": {");
436 output_headers(session, &c);
437 output_json_format(c.out, false, 1, "}");
438
439 // Output samples
440 output_json_format(c.out, true, 1, "\"samples\": [");
441 perf_session__process_events(session);
442 output_json_format(c.out, false, 1, "]");
443 output_json_format(c.out, false, 0, "}");
444 fputc('\n', c.out);
445
446 fprintf(stderr, "[ perf data convert: Converted '%s' into JSON data '%s' ]\n",
447 data.path, output_name);
448
449 fprintf(stderr,
450 "[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n",
451 (ftell(c.out)) / 1024.0 / 1024.0, c.events_count);
452
453 if (c.skipped) {
454 fprintf(stderr, "[ perf data convert: Skipped %" PRIu64 " samples ]\n",
455 c.skipped);
456 }
457
458 ret = 0;
459
460 if (c.ptime_range)
461 zfree(&c.ptime_range);
462
463 err_session_delete:
464 perf_session__delete(session);
465 err_fclose:
466 fclose(c.out);
467 err:
468 return ret;
469 }
470