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