path: root/tools/perf/util/event.c

#include <linux/types.h>
#include "event.h"
#include "debug.h"
#include "session.h"
#include "sort.h"
#include "string.h"
#include "strlist.h"
#include "thread.h"

static const char *event__name[] = {
	[0]			 = "TOTAL",
	[PERF_RECORD_MMAP]	 = "MMAP",
	[PERF_RECORD_LOST]	 = "LOST",
	[PERF_RECORD_COMM]	 = "COMM",
	[PERF_RECORD_EXIT]	 = "EXIT",
	[PERF_RECORD_THROTTLE]	 = "THROTTLE",
	[PERF_RECORD_UNTHROTTLE] = "UNTHROTTLE",
	[PERF_RECORD_FORK]	 = "FORK",
	[PERF_RECORD_READ]	 = "READ",
	[PERF_RECORD_SAMPLE]	 = "SAMPLE",
	[PERF_RECORD_HEADER_ATTR]	 = "ATTR",
	[PERF_RECORD_HEADER_EVENT_TYPE]	 = "EVENT_TYPE",
	[PERF_RECORD_HEADER_TRACING_DATA]	 = "TRACING_DATA",
	[PERF_RECORD_HEADER_BUILD_ID]	 = "BUILD_ID",
	[PERF_RECORD_FINISHED_ROUND]	 = "FINISHED_ROUND",
};

const char *event__get_event_name(unsigned int id)
{
	if (id >= ARRAY_SIZE(event__name))
		return "INVALID";
	if (!event__name[id])
		return "UNKNOWN";
	return event__name[id];
}

static struct sample_data synth_sample = {
	.pid	   = -1,
	.tid	   = -1,
	.time	   = -1,
	.stream_id = -1,
	.cpu	   = -1,
	.period	   = 1,
};

static pid_t event__synthesize_comm(event_t *event, pid_t pid, int full,
				    event__handler_t process,
				    struct perf_session *session)
{
	char filename[PATH_MAX];
	char bf[BUFSIZ];
	FILE *fp;
	size_t size = 0;
	DIR *tasks;
	struct dirent dirent, *next;
	pid_t tgid = 0;

	snprintf(filename, sizeof(filename), "/proc/%d/status", pid);

	fp = fopen(filename, "r");
	if (fp == NULL) {
out_race:
		/*
		 * We raced with a task exiting - just return:
		 */
		pr_debug("couldn't open %s\n", filename);
		return 0;
	}

	memset(&event->comm, 0, sizeof(event->comm));

	while (!event->comm.comm[0] || !event->comm.pid) {
		if (fgets(bf, sizeof(bf), fp) == NULL) {
			pr_warning("couldn't get COMM and pgid, malformed %s\n", filename);
			goto out;
		}

		if (memcmp(bf, "Name:", 5) == 0) {
			char *name = bf + 5;
			while (*name && isspace(*name))
				++name;
			size = strlen(name) - 1;
			memcpy(event->comm.comm, name, size++);
		} else if (memcmp(bf, "Tgid:", 5) == 0) {
			char *tgids = bf + 5;
			while (*tgids && isspace(*tgids))
				++tgids;
			tgid = event->comm.pid = atoi(tgids);
		}
	}

	event->comm.header.type = PERF_RECORD_COMM;
	size = ALIGN(size, sizeof(u64));
	memset(event->comm.comm + size, 0, session->id_hdr_size);
	event->comm.header.size = (sizeof(event->comm) -
				(sizeof(event->comm.comm) - size) +
				session->id_hdr_size);
	if (!full) {
		event->comm.tid = pid;

		process(event, &synth_sample, session);
		goto out;
	}

	snprintf(filename, sizeof(filename), "/proc/%d/task", pid);

	tasks = opendir(filename);
	if (tasks == NULL)
		goto out_race;

	while (!readdir_r(tasks, &dirent, &next) && next) {
		char *end;
		pid = strtol(dirent.d_name, &end, 10);
		if (*end)
			continue;

		event->comm.tid = pid;

		process(event, &synth_sample, session);
	}

	closedir(tasks);
out:
	fclose(fp);

	return tgid;
}

static int event__synthesize_mmap_events(event_t *event, pid_t pid, pid_t tgid,
					 event__handler_t process,
					 struct perf_session *session)
{
	char filename[PATH_MAX];
	FILE *fp;

	snprintf(filename, sizeof(filename), "/proc/%d/maps", pid);

	fp = fopen(filename, "r");
	if (fp == NULL) {
		/*
		 * We raced with a task exiting - just return:
		 */
		pr_debug("couldn't open %s\n", filename);
		return -1;
	}

	event->header.type = PERF_RECORD_MMAP;
	/*
	 * Just like the kernel, see __perf_event_mmap in kernel/perf_event.c
	 */
	event->header.misc =