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

#include <linux/types.h>
#include <sys/mman.h>
#include "event.h"
#include "debug.h"
#include "hist.h"
#include "machine.h"
#include "sort.h"
#include "string.h"
#include "strlist.h"
#include "thread.h"
#include "thread_map.h"
#include "symbol/kallsyms.h"

static const char *perf_event__names[] = {
	[0]					= "TOTAL",
	[PERF_RECORD_MMAP]			= "MMAP",
	[PERF_RECORD_MMAP2]			= "MMAP2",
	[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",
	[PERF_RECORD_ID_INDEX]			= "ID_INDEX",
};

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

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

/*
 * Assumes that the first 4095 bytes of /proc/pid/stat contains
 * the comm, tgid and ppid.
 */
static int perf_event__get_comm_ids(pid_t pid, char *comm, size_t len,
				    pid_t *tgid, pid_t *ppid)
{
	char filename[PATH_MAX];
	char bf[4096];
	int fd;
	size_t size = 0, n;
	char *nl, *name, *tgids, *ppids;

	*tgid = -1;
	*ppid = -1;

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

	fd = open(filename, O_RDONLY);
	if (fd < 0) {
		pr_debug("couldn't open %s\n", filename);
		return -1;
	}

	n = read(fd, bf, sizeof(bf) - 1);
	close(fd);
	if (n <= 0) {
		pr_warning("Couldn't get COMM, tigd and ppid for pid %d\n",
			   pid);
		return -1;
	}
	bf[n] = '\0';

	name = strstr(bf, "Name:");
	tgids = strstr(bf, "Tgid:");
	ppids = strstr(bf, "PPid:");

	if (name) {
		name += 5;  /* strlen("Name:") */

		while (*name && isspace(*name))
			++name;

		nl = strchr(name, '\n');
		if (nl)
			*nl = '\0';

		size = strlen(name);
		if (size >= len)
			size = len - 1;
		memcpy(comm, name, size);
		comm[size] = '\0';
	} else {
		pr_debug("Name: string not found for pid %d\n", pid);
	}

	if (tgids) {
		tgids += 5;  /* strlen("Tgid:") */
		*tgid = atoi(tgids);
	} else {
		pr_debug("Tgid: string not found for pid %d\n", pid);
	}

	if (ppids) {
		ppids += 5;  /* strlen("PPid:") */
		*ppid = atoi(ppids);
	} else {
		pr_debug("PPid: string not found for pid %d\n", pid);
	}

	return 0;
}

static int perf_event__prepare_comm(union perf_event *event, pid_t pid,
				    struct machine *machine,
				    pid_t *tgid, pid_t *ppid)
{
	size_t size;

	*ppid = -1;

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

	if (machine__is_host(machine)) {
		if (perf_event__get_comm_ids(pid, event->comm.comm,
					     sizeof(event->comm.comm),
					     tgid, ppid) != 0) {
			return -1;
		}
	} else {
		*tgid = machine->pid;
	}

	if (*tgid < 0)
		return -1;

	event->comm.pid = *tgid;
	event->comm.header.type = PERF_RECORD_COMM;

	size = strlen(event->comm.comm) + 1;
	size = PERF_ALIGN(size, sizeof(u64));
	memset(event->comm.comm + size, 0, machine->id_hdr_size);
	event->comm.header.size = (sizeof(event->comm) -
				(sizeof(event->comm.comm) - size) +
				machine->id_hdr_size);
	event->comm.tid = pid;

	return 0;
}

static pid_t perf_event__synthesize_comm(struct perf_tool *tool,
					 union perf_event *event, pid_t pid,
					 perf_event__handler_t process,
					 struct machine *machine)
{
	pid_t tgid, ppid;

	if (perf_event__prepare_comm(event, pid, machine, &tgid, &ppid