xref: /linux/tools/perf/util/data-convert-json.c (revision a77ecea7ced2fef7cc0a8ad0323542f781ad9788)
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/env.h"
20 #include "util/dso.h"
21 #include "util/event.h"
22 #include "util/evsel.h"
23 #include "util/evlist.h"
24 #include "util/header.h"
25 #include "util/map.h"
26 #include "util/session.h"
27 #include "util/symbol.h"
28 #include "util/thread.h"
29 #include "util/time-utils.h"
30 #include "util/tool.h"
31 
32 #ifdef HAVE_LIBTRACEEVENT
33 #include <event-parse.h>
34 #endif
35 
36 struct convert_json {
37 	struct perf_tool tool;
38 	FILE *out;
39 	bool first;
40 	struct perf_time_interval *ptime_range;
41 	int range_size;
42 	int range_num;
43 
44 	u64 events_count;
45 	u64 skipped;
46 };
47 
48 // Outputs a JSON-encoded string surrounded by quotes with characters escaped.
49 static void output_json_string(FILE *out, const char *s)
50 {
51 	fputc('"', out);
52 	if (!s)
53 		goto out;
54 
55 	while (*s) {
56 		switch (*s) {
57 
58 		// required escapes with special forms as per RFC 8259
59 		case '"':  fputs("\\\"", out); break;
60 		case '\\': fputs("\\\\", out); break;
61 		case '\b': fputs("\\b", out);  break;
62 		case '\f': fputs("\\f", out);  break;
63 		case '\n': fputs("\\n", out);  break;
64 		case '\r': fputs("\\r", out);  break;
65 		case '\t': fputs("\\t", out);  break;
66 
67 		default:
68 			// all other control characters must be escaped by hex code
69 			if (*s <= 0x1f)
70 				fprintf(out, "\\u%04x", *s);
71 			else
72 				fputc(*s, out);
73 			break;
74 		}
75 
76 		++s;
77 	}
78 out:
79 	fputc('"', out);
80 }
81 
82 // Outputs an optional comma, newline and indentation to delimit a new value
83 // from the previous one in a JSON object or array.
84 static void output_json_delimiters(FILE *out, bool comma, int depth)
85 {
86 	int i;
87 
88 	if (comma)
89 		fputc(',', out);
90 	fputc('\n', out);
91 	for (i = 0; i < depth; ++i)
92 		fputc('\t', out);
93 }
94 
95 // Outputs a printf format string (with delimiter) as a JSON value.
96 __printf(4, 5)
97 static void output_json_format(FILE *out, bool comma, int depth, const char *format, ...)
98 {
99 	va_list args;
100 
101 	output_json_delimiters(out, comma, depth);
102 	va_start(args, format);
103 	vfprintf(out,  format, args);
104 	va_end(args);
105 }
106 
107 // Outputs a JSON key-value pair where the value is a string.
108 static void output_json_key_string(FILE *out, bool comma, int depth,
109 		const char *key, const char *value)
110 {
111 	output_json_delimiters(out, comma, depth);
112 	output_json_string(out, key);
113 	fputs(": ", out);
114 	output_json_string(out, value);
115 }
116 
117 // Outputs a JSON key-value pair where the value is a printf format string.
118 __printf(5, 6)
119 static void output_json_key_format(FILE *out, bool comma, int depth,
120 		const char *key, const char *format, ...)
121 {
122 	va_list args;
123 
124 	output_json_delimiters(out, comma, depth);
125 	output_json_string(out, key);
126 	fputs(": ", out);
127 	va_start(args, format);
128 	vfprintf(out,  format, args);
129 	va_end(args);
130 }
131 
132 static void output_sample_callchain_entry(const struct perf_tool *tool,
133 		u64 ip, struct addr_location *al)
134 {
135 	struct convert_json *c = container_of(tool, struct convert_json, tool);
136 	FILE *out = c->out;
137 
138 	output_json_format(out, false, 4, "{");
139 	output_json_key_format(out, false, 5, "ip", "\"0x%" PRIx64 "\"", ip);
140 
141 	if (al && al->sym && al->sym->namelen) {
142 		struct dso *dso = al->map ? map__dso(al->map) : NULL;
143 
144 		fputc(',', out);
145 		output_json_key_string(out, false, 5, "symbol", al->sym->name);
146 
147 		if (dso) {
148 			const char *dso_name = dso__short_name(dso);
149 
150 			if (dso_name && strlen(dso_name) > 0) {
151 				fputc(',', out);
152 				output_json_key_string(out, false, 5, "dso", dso_name);
153 			}
154 		}
155 	}
156 
157 	output_json_format(out, false, 4, "}");
158 }
159 
160 static int process_sample_event(const struct perf_tool *tool,
161 				union perf_event *event __maybe_unused,
162 				struct perf_sample *sample,
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(sample->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(sample->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 
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 	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",
301 			       perf_env__os_release(env));
302 	output_json_key_string(out, true, 2, "arch", env->arch);
303 
304 	if (env->cpu_desc)
305 		output_json_key_string(out, true, 2, "cpu-desc", env->cpu_desc);
306 
307 	output_json_key_string(out, true, 2, "cpuid", env->cpuid);
308 	output_json_key_format(out, true, 2, "nrcpus-online", "%u", env->nr_cpus_online);
309 	output_json_key_format(out, true, 2, "nrcpus-avail", "%u", env->nr_cpus_avail);
310 
311 	if (env->clock.enabled) {
312 		output_json_key_format(out, true, 2, "clockid",
313 				"%u", env->clock.clockid);
314 		output_json_key_format(out, true, 2, "clock-time",
315 				"%" PRIu64, env->clock.clockid_ns);
316 		output_json_key_format(out, true, 2, "real-time",
317 				"%" PRIu64, env->clock.tod_ns);
318 	}
319 
320 	output_json_key_string(out, true, 2, "perf-version", env->version);
321 
322 	output_json_key_format(out, true, 2, "cmdline", "[");
323 	for (i = 0; i < env->nr_cmdline; i++) {
324 		output_json_delimiters(out, i != 0, 3);
325 		output_json_string(c->out, env->cmdline_argv[i]);
326 	}
327 	output_json_format(out, false, 2, "]");
328 }
329 
330 int bt_convert__perf2json(const char *_input_name, const char *output_name,
331 		struct perf_data_convert_opts *opts __maybe_unused)
332 {
333 	struct perf_session *session;
334 	int fd;
335 	int ret = -1;
336 	struct convert_json c = {
337 		.first = true,
338 		.events_count = 0,
339 		.ptime_range = NULL,
340 		.range_size = 0,
341 		.range_num = 0,
342 		.skipped = 0,
343 	};
344 	struct perf_data data = {
345 		.mode = PERF_DATA_MODE_READ,
346 		.path = _input_name,
347 		.force = opts->force,
348 	};
349 
350 	perf_tool__init(&c.tool, /*ordered_events=*/true);
351 	c.tool.sample         = process_sample_event;
352 	c.tool.mmap           = perf_event__process_mmap;
353 	c.tool.mmap2          = perf_event__process_mmap2;
354 	c.tool.comm           = perf_event__process_comm;
355 	c.tool.namespaces     = perf_event__process_namespaces;
356 	c.tool.cgroup         = perf_event__process_cgroup;
357 	c.tool.exit           = perf_event__process_exit;
358 	c.tool.fork           = perf_event__process_fork;
359 	c.tool.lost           = perf_event__process_lost;
360 #ifdef HAVE_LIBTRACEEVENT
361 	c.tool.tracing_data   = perf_event__process_tracing_data;
362 #endif
363 	c.tool.build_id       = perf_event__process_build_id;
364 	c.tool.id_index       = perf_event__process_id_index;
365 	c.tool.auxtrace_info  = perf_event__process_auxtrace_info;
366 	c.tool.auxtrace       = perf_event__process_auxtrace;
367 	c.tool.event_update   = perf_event__process_event_update;
368 	c.tool.attr           = perf_event__process_attr;
369 	c.tool.feature        = perf_event__process_feature;
370 	c.tool.ordering_requires_timestamps = true;
371 
372 	if (opts->all) {
373 		pr_err("--all is currently unsupported for JSON output.\n");
374 		goto err;
375 	}
376 	if (opts->tod) {
377 		pr_err("--tod is currently unsupported for JSON output.\n");
378 		goto err;
379 	}
380 
381 	fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666);
382 	if (fd == -1) {
383 		if (errno == EEXIST)
384 			pr_err("Output file exists. Use --force to overwrite it.\n");
385 		else
386 			pr_err("Error opening output file!\n");
387 		goto err;
388 	}
389 
390 	c.out = fdopen(fd, "w");
391 	if (!c.out) {
392 		fprintf(stderr, "Error opening output file!\n");
393 		close(fd);
394 		goto err;
395 	}
396 
397 	session = perf_session__new(&data, &c.tool);
398 	if (IS_ERR(session)) {
399 		fprintf(stderr, "Error creating perf session!\n");
400 		goto err_fclose;
401 	}
402 	if (symbol__init(perf_session__env(session)) < 0) {
403 		fprintf(stderr, "Symbol init error!\n");
404 		goto err_session_delete;
405 	}
406 
407 	if (opts->time_str) {
408 		ret = perf_time__parse_for_ranges(opts->time_str, session,
409 						  &c.ptime_range,
410 						  &c.range_size,
411 						  &c.range_num);
412 		if (ret < 0)
413 			goto err_session_delete;
414 	}
415 
416 	// The opening brace is printed manually because it isn't delimited from a
417 	// previous value (i.e. we don't want a leading newline)
418 	fputc('{', c.out);
419 
420 	// Version number for future-proofing. Most additions should be able to be
421 	// done in a backwards-compatible way so this should only need to be bumped
422 	// if some major breaking change must be made.
423 	output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1");
424 
425 	// Output headers
426 	output_json_format(c.out, true, 1, "\"headers\": {");
427 	output_headers(session, &c);
428 	output_json_format(c.out, false, 1, "}");
429 
430 	// Output samples
431 	output_json_format(c.out, true, 1, "\"samples\": [");
432 	perf_session__process_events(session);
433 	output_json_format(c.out, false, 1, "]");
434 	output_json_format(c.out, false, 0, "}");
435 	fputc('\n', c.out);
436 
437 	fprintf(stderr,	"[ perf data convert: Converted '%s' into JSON data '%s' ]\n",
438 		data.path, output_name);
439 
440 	fprintf(stderr,
441 		"[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n",
442 		(ftell(c.out)) / 1024.0 / 1024.0, c.events_count);
443 
444 	if (c.skipped) {
445 		fprintf(stderr,	"[ perf data convert: Skipped %" PRIu64 " samples ]\n",
446 			c.skipped);
447 	}
448 
449 	ret = 0;
450 
451 	if (c.ptime_range)
452 		zfree(&c.ptime_range);
453 
454 err_session_delete:
455 	perf_session__delete(session);
456 err_fclose:
457 	fclose(c.out);
458 err:
459 	return ret;
460 }
461