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 <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(const 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 struct dso *dso = al->map ? map__dso(al->map) : NULL;
132
133 fputc(',', out);
134 output_json_key_string(out, false, 5, "symbol", al->sym->name);
135
136 if (dso) {
137 const char *dso_name = dso__short_name(dso);
138
139 if (dso_name && strlen(dso_name) > 0) {
140 fputc(',', out);
141 output_json_key_string(out, false, 5, "dso", dso_name);
142 }
143 }
144 }
145
146 output_json_format(out, false, 4, "}");
147}
148
149static int process_sample_event(const struct perf_tool *tool,
150 union perf_event *event __maybe_unused,
151 struct perf_sample *sample,
152 struct evsel *evsel __maybe_unused,
153 struct machine *machine)
154{
155 struct convert_json *c = container_of(tool, struct convert_json, tool);
156 FILE *out = c->out;
157 struct addr_location al;
158 u64 sample_type = __evlist__combined_sample_type(evsel->evlist);
159 u8 cpumode = PERF_RECORD_MISC_USER;
160
161 addr_location__init(&al);
162 if (machine__resolve(machine, &al, sample) < 0) {
163 pr_err("Sample resolution failed!\n");
164 addr_location__exit(&al);
165 return -1;
166 }
167
168 ++c->events_count;
169
170 if (c->first)
171 c->first = false;
172 else
173 fputc(',', out);
174 output_json_format(out, false, 2, "{");
175
176 output_json_key_format(out, false, 3, "timestamp", "%" PRIi64, sample->time);
177 output_json_key_format(out, true, 3, "pid", "%i", thread__pid(al.thread));
178 output_json_key_format(out, true, 3, "tid", "%i", thread__tid(al.thread));
179
180 if ((sample_type & PERF_SAMPLE_CPU))
181 output_json_key_format(out, true, 3, "cpu", "%i", sample->cpu);
182 else if (thread__cpu(al.thread) >= 0)
183 output_json_key_format(out, true, 3, "cpu", "%i", thread__cpu(al.thread));
184
185 output_json_key_string(out, true, 3, "comm", thread__comm_str(al.thread));
186
187 output_json_key_format(out, true, 3, "callchain", "[");
188 if (sample->callchain) {
189 unsigned int i;
190 bool ok;
191 bool first_callchain = true;
192
193 for (i = 0; i < sample->callchain->nr; ++i) {
194 u64 ip = sample->callchain->ips[i];
195 struct addr_location tal;
196
197 if (ip >= PERF_CONTEXT_MAX) {
198 switch (ip) {
199 case PERF_CONTEXT_HV:
200 cpumode = PERF_RECORD_MISC_HYPERVISOR;
201 break;
202 case PERF_CONTEXT_KERNEL:
203 cpumode = PERF_RECORD_MISC_KERNEL;
204 break;
205 case PERF_CONTEXT_USER:
206 cpumode = PERF_RECORD_MISC_USER;
207 break;
208 default:
209 pr_debug("invalid callchain context: %"
210 PRId64 "\n", (s64) ip);
211 break;
212 }
213 continue;
214 }
215
216 if (first_callchain)
217 first_callchain = false;
218 else
219 fputc(',', out);
220
221 addr_location__init(&tal);
222 ok = thread__find_symbol(al.thread, cpumode, ip, &tal);
223 output_sample_callchain_entry(tool, ip, al: ok ? &tal : NULL);
224 addr_location__exit(&tal);
225 }
226 } else {
227 output_sample_callchain_entry(tool, ip: sample->ip, al: &al);
228 }
229 output_json_format(out, false, 3, "]");
230
231#ifdef HAVE_LIBTRACEEVENT
232 if (sample->raw_data) {
233 struct tep_event *tp_format = evsel__tp_format(evsel);
234 struct tep_format_field **fields = tp_format ? tep_event_fields(tp_format) : NULL;
235
236 if (fields) {
237 int i = 0;
238
239 while (fields[i]) {
240 struct trace_seq s;
241
242 trace_seq_init(&s);
243 tep_print_field(&s, sample->raw_data, fields[i]);
244 output_json_key_string(out, true, 3, fields[i]->name, s.buffer);
245
246 i++;
247 }
248 free(fields);
249 }
250 }
251#endif
252 output_json_format(out, false, 2, "}");
253 addr_location__exit(&al);
254 return 0;
255}
256
257static void output_headers(struct perf_session *session, struct convert_json *c)
258{
259 struct stat st;
260 const struct perf_header *header = &session->header;
261 const struct perf_env *env = perf_session__env(session);
262 int ret;
263 int fd = perf_data__fd(session->data);
264 int i;
265 FILE *out = c->out;
266
267 output_json_key_format(out, false, 2, "header-version", "%u", header->version);
268
269 ret = fstat(fd, &st);
270 if (ret >= 0) {
271 time_t stctime = st.st_mtime;
272 char buf[256];
273
274 strftime(buf, sizeof(buf), "%FT%TZ", gmtime(&stctime));
275 output_json_key_string(out, true, 2, "captured-on", buf);
276 } else {
277 pr_debug("Failed to get mtime of source file, not writing captured-on");
278 }
279
280 output_json_key_format(out, true, 2, "data-offset", "%" PRIu64, header->data_offset);
281 output_json_key_format(out, true, 2, "data-size", "%" PRIu64, header->data_size);
282 output_json_key_format(out, true, 2, "feat-offset", "%" PRIu64, header->feat_offset);
283
284 output_json_key_string(out, true, 2, "hostname", env->hostname);
285 output_json_key_string(out, true, 2, "os-release", env->os_release);
286 output_json_key_string(out, true, 2, "arch", env->arch);
287
288 if (env->cpu_desc)
289 output_json_key_string(out, true, 2, "cpu-desc", env->cpu_desc);
290
291 output_json_key_string(out, true, 2, "cpuid", env->cpuid);
292 output_json_key_format(out, true, 2, "nrcpus-online", "%u", env->nr_cpus_online);
293 output_json_key_format(out, true, 2, "nrcpus-avail", "%u", env->nr_cpus_avail);
294
295 if (env->clock.enabled) {
296 output_json_key_format(out, true, 2, "clockid",
297 "%u", env->clock.clockid);
298 output_json_key_format(out, true, 2, "clock-time",
299 "%" PRIu64, env->clock.clockid_ns);
300 output_json_key_format(out, true, 2, "real-time",
301 "%" PRIu64, env->clock.tod_ns);
302 }
303
304 output_json_key_string(out, true, 2, "perf-version", env->version);
305
306 output_json_key_format(out, true, 2, "cmdline", "[");
307 for (i = 0; i < env->nr_cmdline; i++) {
308 output_json_delimiters(out, i != 0, 3);
309 output_json_string(c->out, env->cmdline_argv[i]);
310 }
311 output_json_format(out, false, 2, "]");
312}
313
314int bt_convert__perf2json(const char *input_name, const char *output_name,
315 struct perf_data_convert_opts *opts __maybe_unused)
316{
317 struct perf_session *session;
318 int fd;
319 int ret = -1;
320 struct convert_json c = {
321 .first = true,
322 .events_count = 0,
323 };
324 struct perf_data data = {
325 .mode = PERF_DATA_MODE_READ,
326 .path = input_name,
327 .force = opts->force,
328 };
329
330 perf_tool__init(&c.tool, /*ordered_events=*/true);
331 c.tool.sample = process_sample_event;
332 c.tool.mmap = perf_event__process_mmap;
333 c.tool.mmap2 = perf_event__process_mmap2;
334 c.tool.comm = perf_event__process_comm;
335 c.tool.namespaces = perf_event__process_namespaces;
336 c.tool.cgroup = perf_event__process_cgroup;
337 c.tool.exit = perf_event__process_exit;
338 c.tool.fork = perf_event__process_fork;
339 c.tool.lost = perf_event__process_lost;
340#ifdef HAVE_LIBTRACEEVENT
341 c.tool.tracing_data = perf_event__process_tracing_data;
342#endif
343 c.tool.build_id = perf_event__process_build_id;
344 c.tool.id_index = perf_event__process_id_index;
345 c.tool.auxtrace_info = perf_event__process_auxtrace_info;
346 c.tool.auxtrace = perf_event__process_auxtrace;
347 c.tool.event_update = perf_event__process_event_update;
348 c.tool.ordering_requires_timestamps = true;
349
350 if (opts->all) {
351 pr_err("--all is currently unsupported for JSON output.\n");
352 goto err;
353 }
354 if (opts->tod) {
355 pr_err("--tod is currently unsupported for JSON output.\n");
356 goto err;
357 }
358
359 fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666);
360 if (fd == -1) {
361 if (errno == EEXIST)
362 pr_err("Output file exists. Use --force to overwrite it.\n");
363 else
364 pr_err("Error opening output file!\n");
365 goto err;
366 }
367
368 c.out = fdopen(fd, "w");
369 if (!c.out) {
370 fprintf(stderr, "Error opening output file!\n");
371 close(fd);
372 goto err;
373 }
374
375 session = perf_session__new(&data, &c.tool);
376 if (IS_ERR(ptr: session)) {
377 fprintf(stderr, "Error creating perf session!\n");
378 goto err_fclose;
379 }
380 if (symbol__init(perf_session__env(session)) < 0) {
381 fprintf(stderr, "Symbol init error!\n");
382 goto err_session_delete;
383 }
384
385 // The opening brace is printed manually because it isn't delimited from a
386 // previous value (i.e. we don't want a leading newline)
387 fputc('{', c.out);
388
389 // Version number for future-proofing. Most additions should be able to be
390 // done in a backwards-compatible way so this should only need to be bumped
391 // if some major breaking change must be made.
392 output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1");
393
394 // Output headers
395 output_json_format(c.out, true, 1, "\"headers\": {");
396 output_headers(session, c: &c);
397 output_json_format(c.out, false, 1, "}");
398
399 // Output samples
400 output_json_format(c.out, true, 1, "\"samples\": [");
401 perf_session__process_events(session);
402 output_json_format(c.out, false, 1, "]");
403 output_json_format(c.out, false, 0, "}");
404 fputc('\n', c.out);
405
406 fprintf(stderr,
407 "[ perf data convert: Converted '%s' into JSON data '%s' ]\n",
408 data.path, output_name);
409
410 fprintf(stderr,
411 "[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n",
412 (ftell(c.out)) / 1024.0 / 1024.0, c.events_count);
413
414 ret = 0;
415err_session_delete:
416 perf_session__delete(session);
417err_fclose:
418 fclose(c.out);
419err:
420 return ret;
421}
422

source code of linux/tools/perf/util/data-convert-json.c