// SPDX-License-Identifier: GPL-2.0-only
/*
* JSON export.
*
* Copyright (C) 2021, CodeWeavers Inc. <[email protected]>
*/
#include "data-convert.h"
#include <fcntl.h>
#include <inttypes.h>
#include <sys/stat.h>
#include <unistd.h>
#include "linux/compiler.h"
#include "linux/err.h"
#include "util/auxtrace.h"
#include "util/debug.h"
#include "util/dso.h"
#include "util/event.h"
#include "util/evsel.h"
#include "util/evlist.h"
#include "util/header.h"
#include "util/map.h"
#include "util/session.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/tool.h"
#ifdef HAVE_LIBTRACEEVENT
#include <traceevent/event-parse.h>
#endif
struct convert_json {
struct perf_tool tool;
FILE *out;
bool first;
u64 events_count;
};
// Outputs a JSON-encoded string surrounded by quotes with characters escaped.
static void output_json_string(FILE *out, const char *s)
{
fputc('"', out);
while (*s) {
switch (*s) {
// required escapes with special forms as per RFC 8259
case '"': fputs("\\\"", out); break;
case '\\': fputs("\\\\", out); break;
case '\b': fputs("\\b", out); break;
case '\f': fputs("\\f", out); break;
case '\n': fputs("\\n", out); break;
case '\r': fputs("\\r", out); break;
case '\t': fputs("\\t", out); break;
default:
// all other control characters must be escaped by hex code
if (*s <= 0x1f)
fprintf(out, "\\u%04x", *s);
else
fputc(*s, out);
break;
}
++s;
}
fputc('"', out);
}
// Outputs an optional comma, newline and indentation to delimit a new value
// from the previous one in a JSON object or array.
static void output_json_delimiters(FILE *out, bool comma, int depth)
{
int i;
if (comma)
fputc(',', out);
fputc('\n', out);
for (i = 0; i < depth; ++i)
fputc('\t', out);
}
// Outputs a printf format string (with delimiter) as a JSON value.
__printf(4, 5)
static void output_json_format(FILE *out, bool comma, int depth, const char *format, ...)
{
va_list args;
output_json_delimiters(out, comma, depth);
va_start(args, format);
vfprintf(out, format, args);
va_end(args);
}
// Outputs a JSON key-value pair where the value is a string.
static void output_json_key_string(FILE *out, bool comma, int depth,
const char *key, const char *value)
{
output_json_delimiters(out, comma, depth);
output_json_string(out, key);
fputs(": ", out);
output_json_string(out, value);
}
// Outputs a JSON key-value pair where the value is a printf format string.
__printf(5, 6)
static void output_json_key_format(FILE *out, bool comma, int depth,
const char *key, const char *format, ...)
{
va_list args;
output_json_delimiters(out, comma, depth);
output_json_string(out, key);
fputs(": ", out);
va_start(args, format);
vfprintf(out, format, args);
va_end(args);
}
static void output_sample_callchain_entry(struct perf_tool *tool,
u64 ip, struct addr_location *al)
{
struct convert_json *c = container_of(tool, struct convert_json, tool);
FILE *out = c->out;
output_json_format(out, false, 4, "{");
output_json_key_format(out, false, 5, "ip", "\"0x%" PRIx64 "\"", ip);
if (al && al->sym && al->sym->namelen) {
struct dso *dso = al->map ? map__dso(al->map) : NULL;
fputc(',', out);
output_json_key_string(out, false, 5, "symbol", al->sym->name);
if (dso) {
const char *dso_name = dso__short_name(dso);
if (dso_name && strlen(dso_name) > 0) {
fputc(',', out);
output_json_key_string(out, false, 5, "dso", dso_name);
}
}
}
output_json_format(out, false, 4, "}");
}
static int 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)
{
struct convert_json *c = container_of(tool, struct convert_json, tool);
FILE *out = c->out;
struct addr_location al;
u64 sample_type = __evlist__combined_sample_type(evsel->evlist);
u8 cpumode = PERF_RECORD_MISC_USER;
addr_location__init(&al);
if (machine__resolve(machine, &al, sample) < 0) {
pr_err("Sample resolution failed!\n");
addr_location__exit(&al);
return -1;
}
++c->events_count;
if (c->first)
c->first = false;
else
fputc(',', out);
output_json_format(out, false, 2, "{");
output_json_key_format(out, false, 3, "timestamp", "%" PRIi64, sample->time);
output_json_key_format(out, true, 3, "pid", "%i", thread__pid(al.thread));
output_json_key_format(out, true, 3, "tid", "%i", thread__tid(al.thread));
if ((sample_type & PERF_SAMPLE_CPU))
output_json_key_format(out, true, 3, "cpu", "%i", sample->cpu);
else if (thread__cpu(al.thread) >= 0)
output_json_key_format(out, true, 3, "cpu", "%i", thread__cpu(al.thread));
output_json_key_string(out, true, 3, "comm", thread__comm_str(al.thread));
output_json_key_format(out, true, 3, "callchain", "[");
if (sample->callchain) {
unsigned int i;
bool ok;
bool first_callchain = true;
for (i = 0; i < sample->callchain->nr; ++i) {
u64 ip = sample->callchain->ips[i];
struct addr_location tal;
if (ip >= PERF_CONTEXT_MAX) {
switch (ip) {
case PERF_CONTEXT_HV:
cpumode = PERF_RECORD_MISC_HYPERVISOR;
break;
case PERF_CONTEXT_KERNEL:
cpumode = PERF_RECORD_MISC_KERNEL;
break;
case PERF_CONTEXT_USER:
cpumode = PERF_RECORD_MISC_USER;
break;
default:
pr_debug("invalid callchain context: %"
PRId64 "\n", (s64) ip);
break;
}
continue;
}
if (first_callchain)
first_callchain = false;
else
fputc(',', out);
addr_location__init(&tal);
ok = thread__find_symbol(al.thread, cpumode, ip, &tal);
output_sample_callchain_entry(tool, ip, ok ? &tal : NULL);
addr_location__exit(&tal);
}
} else {
output_sample_callchain_entry(tool, sample->ip, &al);
}
output_json_format(out, false, 3, "]");
#ifdef HAVE_LIBTRACEEVENT
if (sample->raw_data) {
int i;
struct tep_format_field **fields;
fields = tep_event_fields(evsel->tp_format);
if (fields) {
i = 0;
while (fields[i]) {
struct trace_seq s;
trace_seq_init(&s);
tep_print_field(&s, sample->raw_data, fields[i]);
output_json_key_string(out, true, 3, fields[i]->name, s.buffer);
i++;
}
free(fields);
}
}
#endif
output_json_format(out, false, 2, "}");
addr_location__exit(&al);
return 0;
}
static void output_headers(struct perf_session *session, struct convert_json *c)
{
struct stat st;
struct perf_header *header = &session->header;
int ret;
int fd = perf_data__fd(session->data);
int i;
FILE *out = c->out;
output_json_key_format(out, false, 2, "header-version", "%u", header->version);
ret = fstat(fd, &st);
if (ret >= 0) {
time_t stctime = st.st_mtime;
char buf[256];
strftime(buf, sizeof(buf), "%FT%TZ", gmtime(&stctime));
output_json_key_string(out, true, 2, "captured-on", buf);
} else {
pr_debug("Failed to get mtime of source file, not writing captured-on");
}
output_json_key_format(out, true, 2, "data-offset", "%" PRIu64, header->data_offset);
output_json_key_format(out, true, 2, "data-size", "%" PRIu64, header->data_size);
output_json_key_format(out, true, 2, "feat-offset", "%" PRIu64, header->feat_offset);
output_json_key_string(out, true, 2, "hostname", header->env.hostname);
output_json_key_string(out, true, 2, "os-release", header->env.os_release);
output_json_key_string(out, true, 2, "arch", header->env.arch);
if (header->env.cpu_desc)
output_json_key_string(out, true, 2, "cpu-desc", header->env.cpu_desc);
output_json_key_string(out, true, 2, "cpuid", header->env.cpuid);
output_json_key_format(out, true, 2, "nrcpus-online", "%u", header->env.nr_cpus_online);
output_json_key_format(out, true, 2, "nrcpus-avail", "%u", header->env.nr_cpus_avail);
if (header->env.clock.enabled) {
output_json_key_format(out, true, 2, "clockid",
"%u", header->env.clock.clockid);
output_json_key_format(out, true, 2, "clock-time",
"%" PRIu64, header->env.clock.clockid_ns);
output_json_key_format(out, true, 2, "real-time",
"%" PRIu64, header->env.clock.tod_ns);
}
output_json_key_string(out, true, 2, "perf-version", header->env.version);
output_json_key_format(out, true, 2, "cmdline", "[");
for (i = 0; i < header->env.nr_cmdline; i++) {
output_json_delimiters(out, i != 0, 3);
output_json_string(c->out, header->env.cmdline_argv[i]);
}
output_json_format(out, false, 2, "]");
}
int bt_convert__perf2json(const char *input_name, const char *output_name,
struct perf_data_convert_opts *opts __maybe_unused)
{
struct perf_session *session;
int fd;
int ret = -1;
struct convert_json c = {
.tool = {
.sample = process_sample_event,
.mmap = perf_event__process_mmap,
.mmap2 = perf_event__process_mmap2,
.comm = perf_event__process_comm,
.namespaces = perf_event__process_namespaces,
.cgroup = perf_event__process_cgroup,
.exit = perf_event__process_exit,
.fork = perf_event__process_fork,
.lost = perf_event__process_lost,
#ifdef HAVE_LIBTRACEEVENT
.tracing_data = perf_event__process_tracing_data,
#endif
.build_id = perf_event__process_build_id,
.id_index = perf_event__process_id_index,
.auxtrace_info = perf_event__process_auxtrace_info,
.auxtrace = perf_event__process_auxtrace,
.event_update = perf_event__process_event_update,
.ordered_events = true,
.ordering_requires_timestamps = true,
},
.first = true,
.events_count = 0,
};
struct perf_data data = {
.mode = PERF_DATA_MODE_READ,
.path = input_name,
.force = opts->force,
};
if (opts->all) {
pr_err("--all is currently unsupported for JSON output.\n");
goto err;
}
if (opts->tod) {
pr_err("--tod is currently unsupported for JSON output.\n");
goto err;
}
fd = open(output_name, O_CREAT | O_WRONLY | (opts->force ? O_TRUNC : O_EXCL), 0666);
if (fd == -1) {
if (errno == EEXIST)
pr_err("Output file exists. Use --force to overwrite it.\n");
else
pr_err("Error opening output file!\n");
goto err;
}
c.out = fdopen(fd, "w");
if (!c.out) {
fprintf(stderr, "Error opening output file!\n");
close(fd);
goto err;
}
session = perf_session__new(&data, &c.tool);
if (IS_ERR(session)) {
fprintf(stderr, "Error creating perf session!\n");
goto err_fclose;
}
if (symbol__init(&session->header.env) < 0) {
fprintf(stderr, "Symbol init error!\n");
goto err_session_delete;
}
// The opening brace is printed manually because it isn't delimited from a
// previous value (i.e. we don't want a leading newline)
fputc('{', c.out);
// Version number for future-proofing. Most additions should be able to be
// done in a backwards-compatible way so this should only need to be bumped
// if some major breaking change must be made.
output_json_format(c.out, false, 1, "\"linux-perf-json-version\": 1");
// Output headers
output_json_format(c.out, true, 1, "\"headers\": {");
output_headers(session, &c);
output_json_format(c.out, false, 1, "}");
// Output samples
output_json_format(c.out, true, 1, "\"samples\": [");
perf_session__process_events(session);
output_json_format(c.out, false, 1, "]");
output_json_format(c.out, false, 0, "}");
fputc('\n', c.out);
fprintf(stderr,
"[ perf data convert: Converted '%s' into JSON data '%s' ]\n",
data.path, output_name);
fprintf(stderr,
"[ perf data convert: Converted and wrote %.3f MB (%" PRIu64 " samples) ]\n",
(ftell(c.out)) / 1024.0 / 1024.0, c.events_count);
ret = 0;
err_session_delete:
perf_session__delete(session);
err_fclose:
fclose(c.out);
err:
return ret;
}
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