tools/perf/util/trace-event-info.c - kernel/windcharger - Git at Google

 /*
  * Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com>
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; version 2 of the License (not later!)
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  */
 #include "util.h"
 #include <dirent.h>
 #include <mntent.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
 #include <pthread.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <linux/list.h>
 #include <linux/kernel.h>

 #include "../perf.h"
 #include "trace-event.h"
 #include "debugfs.h"
 #include "evsel.h"

 #define VERSION "0.5"

 #define TRACE_CTRL	"tracing_on"
 #define TRACE		"trace"
 #define AVAILABLE	"available_tracers"
 #define CURRENT		"current_tracer"
 #define ITER_CTRL	"trace_options"
 #define MAX_LATENCY	"tracing_max_latency"

 unsigned int page_size;

 static const char *output_file = "trace.info";
 static int output_fd;

 struct event_list {
 	struct event_list *next;
 	const char *event;
 };

 struct events {
 	struct events *sibling;
 	struct events *children;
 	struct events *next;
 	char *name;
 };


 void *malloc_or_die(unsigned int size)
 {
 	void *data;

 	data = malloc(size);
 	if (!data)
 		die("malloc");
 	return data;
 }

 static const char *find_debugfs(void)
 {
 	const char *path = debugfs_mount(NULL);

 	if (!path)
 		die("Your kernel not support debugfs filesystem");

 	return path;
 }

 /*
  * Finds the path to the debugfs/tracing
  * Allocates the string and stores it.
  */
 static const char *find_tracing_dir(void)
 {
 	static char *tracing;
 	static int tracing_found;
 	const char *debugfs;

 	if (tracing_found)
 		return tracing;

 	debugfs = find_debugfs();

 	tracing = malloc_or_die(strlen(debugfs) + 9);

 	sprintf(tracing, "%s/tracing", debugfs);

 	tracing_found = 1;
 	return tracing;
 }

 static char *get_tracing_file(const char *name)
 {
 	const char *tracing;
 	char *file;

 	tracing = find_tracing_dir();
 	if (!tracing)
 		return NULL;

 	file = malloc_or_die(strlen(tracing) + strlen(name) + 2);

 	sprintf(file, "%s/%s", tracing, name);
 	return file;
 }

 static void put_tracing_file(char *file)
 {
 	free(file);
 }

 static ssize_t calc_data_size;

 static ssize_t write_or_die(const void *buf, size_t len)
 {
 	int ret;

 	if (calc_data_size) {
 		calc_data_size += len;
 		return len;
 	}

 	ret = write(output_fd, buf, len);
 	if (ret < 0)
 		die("writing to '%s'", output_file);

 	return ret;
 }

 int bigendian(void)
 {
 	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
 	unsigned int *ptr;

 	ptr = (unsigned int *)(void *)str;
 	return *ptr == 0x01020304;
 }

 /* unfortunately, you can not stat debugfs or proc files for size */
 static void record_file(const char *file, size_t hdr_sz)
 {
 	unsigned long long size = 0;
 	char buf[BUFSIZ], *sizep;
 	off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
 	int r, fd;

 	fd = open(file, O_RDONLY);
 	if (fd < 0)
 		die("Can't read '%s'", file);

 	/* put in zeros for file size, then fill true size later */
 	if (hdr_sz)
 		write_or_die(&size, hdr_sz);

 	do {
 		r = read(fd, buf, BUFSIZ);
 		if (r > 0) {
 			size += r;
 			write_or_die(buf, r);
 		}
 	} while (r > 0);
 	close(fd);

 	/* ugh, handle big-endian hdr_size == 4 */
 	sizep = (char*)&size;
 	if (bigendian())
 		sizep += sizeof(u64) - hdr_sz;

 	if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0)
 		die("writing to %s", output_file);
 }

 static void read_header_files(void)
 {
 	char *path;
 	struct stat st;

 	path = get_tracing_file("events/header_page");
 	if (stat(path, &st) < 0)
 		die("can't read '%s'", path);

 	write_or_die("header_page", 12);
 	record_file(path, 8);
 	put_tracing_file(path);

 	path = get_tracing_file("events/header_event");
 	if (stat(path, &st) < 0)
 		die("can't read '%s'", path);

 	write_or_die("header_event", 13);
 	record_file(path, 8);
 	put_tracing_file(path);
 }

 static bool name_in_tp_list(char *sys, struct tracepoint_path *tps)
 {
 	while (tps) {
 		if (!strcmp(sys, tps->name))
 			return true;
 		tps = tps->next;
 	}

 	return false;
 }

 static void copy_event_system(const char *sys, struct tracepoint_path *tps)
 {
 	struct dirent *dent;
 	struct stat st;
 	char *format;
 	DIR *dir;
 	int count = 0;
 	int ret;

 	dir = opendir(sys);
 	if (!dir)
 		die("can't read directory '%s'", sys);

 	while ((dent = readdir(dir))) {
 		if (dent->d_type != DT_DIR ||
 		    strcmp(dent->d_name, ".") == 0 ||
 		    strcmp(dent->d_name, "..") == 0 ||
 		    !name_in_tp_list(dent->d_name, tps))
 			continue;
 		format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
 		sprintf(format, "%s/%s/format", sys, dent->d_name);
 		ret = stat(format, &st);
 		free(format);
 		if (ret < 0)
 			continue;
 		count++;
 	}

 	write_or_die(&count, 4);

 	rewinddir(dir);
 	while ((dent = readdir(dir))) {
 		if (dent->d_type != DT_DIR ||
 		    strcmp(dent->d_name, ".") == 0 ||
 		    strcmp(dent->d_name, "..") == 0 ||
 		    !name_in_tp_list(dent->d_name, tps))
 			continue;
 		format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
 		sprintf(format, "%s/%s/format", sys, dent->d_name);
 		ret = stat(format, &st);

 		if (ret >= 0)
 			record_file(format, 8);

 		free(format);
 	}
 	closedir(dir);
 }

 static void read_ftrace_files(struct tracepoint_path *tps)
 {
 	char *path;

 	path = get_tracing_file("events/ftrace");

 	copy_event_system(path, tps);

 	put_tracing_file(path);
 }

 static bool system_in_tp_list(char *sys, struct tracepoint_path *tps)
 {
 	while (tps) {
 		if (!strcmp(sys, tps->system))
 			return true;
 		tps = tps->next;
 	}

 	return false;
 }

 static void read_event_files(struct tracepoint_path *tps)
 {
 	struct dirent *dent;
 	struct stat st;
 	char *path;
 	char *sys;
 	DIR *dir;
 	int count = 0;
 	int ret;

 	path = get_tracing_file("events");

 	dir = opendir(path);
 	if (!dir)
 		die("can't read directory '%s'", path);

 	while ((dent = readdir(dir))) {
 		if (dent->d_type != DT_DIR ||
 		    strcmp(dent->d_name, ".") == 0 ||
 		    strcmp(dent->d_name, "..") == 0 ||
 		    strcmp(dent->d_name, "ftrace") == 0 ||
 		    !system_in_tp_list(dent->d_name, tps))
 			continue;
 		count++;
 	}

 	write_or_die(&count, 4);

 	rewinddir(dir);
 	while ((dent = readdir(dir))) {
 		if (dent->d_type != DT_DIR ||
 		    strcmp(dent->d_name, ".") == 0 ||
 		    strcmp(dent->d_name, "..") == 0 ||
 		    strcmp(dent->d_name, "ftrace") == 0 ||
 		    !system_in_tp_list(dent->d_name, tps))
 			continue;
 		sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
 		sprintf(sys, "%s/%s", path, dent->d_name);
 		ret = stat(sys, &st);
 		if (ret >= 0) {
 			write_or_die(dent->d_name, strlen(dent->d_name) + 1);
 			copy_event_system(sys, tps);
 		}
 		free(sys);
 	}

 	closedir(dir);
 	put_tracing_file(path);
 }

 static void read_proc_kallsyms(void)
 {
 	unsigned int size;
 	const char *path = "/proc/kallsyms";
 	struct stat st;
 	int ret;

 	ret = stat(path, &st);
 	if (ret < 0) {
 		/* not found */
 		size = 0;
 		write_or_die(&size, 4);
 		return;
 	}
 	record_file(path, 4);
 }

 static void read_ftrace_printk(void)
 {
 	unsigned int size;
 	char *path;
 	struct stat st;
 	int ret;

 	path = get_tracing_file("printk_formats");
 	ret = stat(path, &st);
 	if (ret < 0) {
 		/* not found */
 		size = 0;
 		write_or_die(&size, 4);
 		goto out;
 	}
 	record_file(path, 4);

 out:
 	put_tracing_file(path);
 }

 static struct tracepoint_path *
 get_tracepoints_path(struct list_head *pattrs)
 {
 	struct tracepoint_path path, *ppath = &path;
 	struct perf_evsel *pos;
 	int nr_tracepoints = 0;

 	list_for_each_entry(pos, pattrs, node) {
 		if (pos->attr.type != PERF_TYPE_TRACEPOINT)
 			continue;
 		++nr_tracepoints;
 		ppath->next = tracepoint_id_to_path(pos->attr.config);
 		if (!ppath->next)
 			die("%s\n", "No memory to alloc tracepoints list");
 		ppath = ppath->next;
 	}

 	return nr_tracepoints > 0 ? path.next : NULL;
 }

 static void
 put_tracepoints_path(struct tracepoint_path *tps)
 {
 	while (tps) {
 		struct tracepoint_path *t = tps;

 		tps = tps->next;
 		free(t->name);
 		free(t->system);
 		free(t);
 	}
 }

 bool have_tracepoints(struct list_head *pattrs)
 {
 	struct perf_evsel *pos;

 	list_for_each_entry(pos, pattrs, node)
 		if (pos->attr.type == PERF_TYPE_TRACEPOINT)
 			return true;

 	return false;
 }

 static void tracing_data_header(void)
 {
 	char buf[20];

 	/* just guessing this is someone's birthday.. ;) */
 	buf[0] = 23;
 	buf[1] = 8;
 	buf[2] = 68;
 	memcpy(buf + 3, "tracing", 7);

 	write_or_die(buf, 10);

 	write_or_die(VERSION, strlen(VERSION) + 1);

 	/* save endian */
 	if (bigendian())
 		buf[0] = 1;
 	else
 		buf[0] = 0;

 	write_or_die(buf, 1);

 	/* save size of long */
 	buf[0] = sizeof(long);
 	write_or_die(buf, 1);

 	/* save page_size */
 	page_size = sysconf(_SC_PAGESIZE);
 	write_or_die(&page_size, 4);
 }

 struct tracing_data *tracing_data_get(struct list_head *pattrs,
 				      int fd, bool temp)
 {
 	struct tracepoint_path *tps;
 	struct tracing_data *tdata;

 	output_fd = fd;

 	tps = get_tracepoints_path(pattrs);
 	if (!tps)
 		return NULL;

 	tdata = malloc_or_die(sizeof(*tdata));
 	tdata->temp = temp;
 	tdata->size = 0;

 	if (temp) {
 		int temp_fd;

 		snprintf(tdata->temp_file, sizeof(tdata->temp_file),
 			 "/tmp/perf-XXXXXX");
 		if (!mkstemp(tdata->temp_file))
 			die("Can't make temp file");

 		temp_fd = open(tdata->temp_file, O_RDWR);
 		if (temp_fd < 0)
 			die("Can't read '%s'", tdata->temp_file);

 		/*
 		 * Set the temp file the default output, so all the
 		 * tracing data are stored into it.
 		 */
 		output_fd = temp_fd;
 	}

 	tracing_data_header();
 	read_header_files();
 	read_ftrace_files(tps);
 	read_event_files(tps);
 	read_proc_kallsyms();
 	read_ftrace_printk();

 	/*
 	 * All tracing data are stored by now, we can restore
 	 * the default output file in case we used temp file.
 	 */
 	if (temp) {
 		tdata->size = lseek(output_fd, 0, SEEK_CUR);
 		close(output_fd);
 		output_fd = fd;
 	}

 	put_tracepoints_path(tps);
 	return tdata;
 }

 void tracing_data_put(struct tracing_data *tdata)
 {
 	if (tdata->temp) {
 		record_file(tdata->temp_file, 0);
 		unlink(tdata->temp_file);
 	}

 	free(tdata);
 }

 int read_tracing_data(int fd, struct list_head *pattrs)
 {
 	struct tracing_data *tdata;

 	/*
 	 * We work over the real file, so we can write data
 	 * directly, no temp file is needed.
 	 */
 	tdata = tracing_data_get(pattrs, fd, false);
 	if (!tdata)
 		return -ENOMEM;

 	tracing_data_put(tdata);
 	return 0;
 }
	/*
	* Copyright (C) 2008,2009, Steven Rostedt <srostedt@redhat.com>
	*
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; version 2 of the License (not later!)
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
	*/
	#include "util.h"
	#include <dirent.h>
	#include <mntent.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <stdarg.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/wait.h>
	#include <pthread.h>
	#include <fcntl.h>
	#include <unistd.h>
	#include <errno.h>
	#include <stdbool.h>
	#include <linux/list.h>
	#include <linux/kernel.h>

	#include "../perf.h"
	#include "trace-event.h"
	#include "debugfs.h"
	#include "evsel.h"

	#define VERSION "0.5"

	#define TRACE_CTRL "tracing_on"
	#define TRACE "trace"
	#define AVAILABLE "available_tracers"
	#define CURRENT "current_tracer"
	#define ITER_CTRL "trace_options"
	#define MAX_LATENCY "tracing_max_latency"

	unsigned int page_size;

	static const char *output_file = "trace.info";
	static int output_fd;

	struct event_list {
	struct event_list *next;
	const char *event;
	};

	struct events {
	struct events *sibling;
	struct events *children;
	struct events *next;
	char *name;
	};


	void *malloc_or_die(unsigned int size)
	{
	void *data;

	data = malloc(size);
	if (!data)
	die("malloc");
	return data;
	}

	static const char *find_debugfs(void)
	{
	const char *path = debugfs_mount(NULL);

	if (!path)
	die("Your kernel not support debugfs filesystem");

	return path;
	}

	/*
	* Finds the path to the debugfs/tracing
	* Allocates the string and stores it.
	*/
	static const char *find_tracing_dir(void)
	{
	static char *tracing;
	static int tracing_found;
	const char *debugfs;

	if (tracing_found)
	return tracing;

	debugfs = find_debugfs();

	tracing = malloc_or_die(strlen(debugfs) + 9);

	sprintf(tracing, "%s/tracing", debugfs);

	tracing_found = 1;
	return tracing;
	}

	static char get_tracing_file(const char name)
	{
	const char *tracing;
	char *file;

	tracing = find_tracing_dir();
	if (!tracing)
	return NULL;

	file = malloc_or_die(strlen(tracing) + strlen(name) + 2);

	sprintf(file, "%s/%s", tracing, name);
	return file;
	}

	static void put_tracing_file(char *file)
	{
	free(file);
	}

	static ssize_t calc_data_size;

	static ssize_t write_or_die(const void *buf, size_t len)
	{
	int ret;

	if (calc_data_size) {
	calc_data_size += len;
	return len;
	}

	ret = write(output_fd, buf, len);
	if (ret < 0)
	die("writing to '%s'", output_file);

	return ret;
	}

	int bigendian(void)
	{
	unsigned char str[] = { 0x1, 0x2, 0x3, 0x4, 0x0, 0x0, 0x0, 0x0};
	unsigned int *ptr;

	ptr = (unsigned int )(void )str;
	return *ptr == 0x01020304;
	}

	/* unfortunately, you can not stat debugfs or proc files for size */
	static void record_file(const char *file, size_t hdr_sz)
	{
	unsigned long long size = 0;
	char buf[BUFSIZ], *sizep;
	off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR);
	int r, fd;

	fd = open(file, O_RDONLY);
	if (fd < 0)
	die("Can't read '%s'", file);

	/* put in zeros for file size, then fill true size later */
	if (hdr_sz)
	write_or_die(&size, hdr_sz);

	do {
	r = read(fd, buf, BUFSIZ);
	if (r > 0) {
	size += r;
	write_or_die(buf, r);
	}
	} while (r > 0);
	close(fd);

	/* ugh, handle big-endian hdr_size == 4 */
	sizep = (char*)&size;
	if (bigendian())
	sizep += sizeof(u64) - hdr_sz;

	if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0)
	die("writing to %s", output_file);
	}

	static void read_header_files(void)
	{
	char *path;
	struct stat st;

	path = get_tracing_file("events/header_page");
	if (stat(path, &st) < 0)
	die("can't read '%s'", path);

	write_or_die("header_page", 12);
	record_file(path, 8);
	put_tracing_file(path);

	path = get_tracing_file("events/header_event");
	if (stat(path, &st) < 0)
	die("can't read '%s'", path);

	write_or_die("header_event", 13);
	record_file(path, 8);
	put_tracing_file(path);
	}

	static bool name_in_tp_list(char sys, struct tracepoint_path tps)
	{
	while (tps) {
	if (!strcmp(sys, tps->name))
	return true;
	tps = tps->next;
	}

	return false;
	}

	static void copy_event_system(const char sys, struct tracepoint_path tps)
	{
	struct dirent *dent;
	struct stat st;
	char *format;
	DIR *dir;
	int count = 0;
	int ret;

	dir = opendir(sys);
	if (!dir)
	die("can't read directory '%s'", sys);

	while ((dent = readdir(dir))) {
	if (dent->d_type != DT_DIR \|\|
	strcmp(dent->d_name, ".") == 0 \|\|
	strcmp(dent->d_name, "..") == 0 \|\|
	!name_in_tp_list(dent->d_name, tps))
	continue;
	format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
	sprintf(format, "%s/%s/format", sys, dent->d_name);
	ret = stat(format, &st);
	free(format);
	if (ret < 0)
	continue;
	count++;
	}

	write_or_die(&count, 4);

	rewinddir(dir);
	while ((dent = readdir(dir))) {
	if (dent->d_type != DT_DIR \|\|
	strcmp(dent->d_name, ".") == 0 \|\|
	strcmp(dent->d_name, "..") == 0 \|\|
	!name_in_tp_list(dent->d_name, tps))
	continue;
	format = malloc_or_die(strlen(sys) + strlen(dent->d_name) + 10);
	sprintf(format, "%s/%s/format", sys, dent->d_name);
	ret = stat(format, &st);

	if (ret >= 0)
	record_file(format, 8);

	free(format);
	}
	closedir(dir);
	}

	static void read_ftrace_files(struct tracepoint_path *tps)
	{
	char *path;

	path = get_tracing_file("events/ftrace");

	copy_event_system(path, tps);

	put_tracing_file(path);
	}

	static bool system_in_tp_list(char sys, struct tracepoint_path tps)
	{
	while (tps) {
	if (!strcmp(sys, tps->system))
	return true;
	tps = tps->next;
	}

	return false;
	}

	static void read_event_files(struct tracepoint_path *tps)
	{
	struct dirent *dent;
	struct stat st;
	char *path;
	char *sys;
	DIR *dir;
	int count = 0;
	int ret;

	path = get_tracing_file("events");

	dir = opendir(path);
	if (!dir)
	die("can't read directory '%s'", path);

	while ((dent = readdir(dir))) {
	if (dent->d_type != DT_DIR \|\|
	strcmp(dent->d_name, ".") == 0 \|\|
	strcmp(dent->d_name, "..") == 0 \|\|
	strcmp(dent->d_name, "ftrace") == 0 \|\|
	!system_in_tp_list(dent->d_name, tps))
	continue;
	count++;
	}

	write_or_die(&count, 4);

	rewinddir(dir);
	while ((dent = readdir(dir))) {
	if (dent->d_type != DT_DIR \|\|
	strcmp(dent->d_name, ".") == 0 \|\|
	strcmp(dent->d_name, "..") == 0 \|\|
	strcmp(dent->d_name, "ftrace") == 0 \|\|
	!system_in_tp_list(dent->d_name, tps))
	continue;
	sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
	sprintf(sys, "%s/%s", path, dent->d_name);
	ret = stat(sys, &st);
	if (ret >= 0) {
	write_or_die(dent->d_name, strlen(dent->d_name) + 1);
	copy_event_system(sys, tps);
	}
	free(sys);
	}

	closedir(dir);
	put_tracing_file(path);
	}

	static void read_proc_kallsyms(void)
	{
	unsigned int size;
	const char *path = "/proc/kallsyms";
	struct stat st;
	int ret;

	ret = stat(path, &st);
	if (ret < 0) {
	/* not found */
	size = 0;
	write_or_die(&size, 4);
	return;
	}
	record_file(path, 4);
	}

	static void read_ftrace_printk(void)
	{
	unsigned int size;
	char *path;
	struct stat st;
	int ret;

	path = get_tracing_file("printk_formats");
	ret = stat(path, &st);
	if (ret < 0) {
	/* not found */
	size = 0;
	write_or_die(&size, 4);
	goto out;
	}
	record_file(path, 4);

	out:
	put_tracing_file(path);
	}

	static struct tracepoint_path *
	get_tracepoints_path(struct list_head *pattrs)
	{
	struct tracepoint_path path, *ppath = &path;
	struct perf_evsel *pos;
	int nr_tracepoints = 0;

	list_for_each_entry(pos, pattrs, node) {
	if (pos->attr.type != PERF_TYPE_TRACEPOINT)
	continue;
	++nr_tracepoints;
	ppath->next = tracepoint_id_to_path(pos->attr.config);
	if (!ppath->next)
	die("%s\n", "No memory to alloc tracepoints list");
	ppath = ppath->next;
	}

	return nr_tracepoints > 0 ? path.next : NULL;
	}

	static void
	put_tracepoints_path(struct tracepoint_path *tps)
	{
	while (tps) {
	struct tracepoint_path *t = tps;

	tps = tps->next;
	free(t->name);
	free(t->system);
	free(t);
	}
	}

	bool have_tracepoints(struct list_head *pattrs)
	{
	struct perf_evsel *pos;

	list_for_each_entry(pos, pattrs, node)
	if (pos->attr.type == PERF_TYPE_TRACEPOINT)
	return true;

	return false;
	}

	static void tracing_data_header(void)
	{
	char buf[20];

	/* just guessing this is someone's birthday.. ;) */
	buf[0] = 23;
	buf[1] = 8;
	buf[2] = 68;
	memcpy(buf + 3, "tracing", 7);

	write_or_die(buf, 10);

	write_or_die(VERSION, strlen(VERSION) + 1);

	/* save endian */
	if (bigendian())
	buf[0] = 1;
	else
	buf[0] = 0;

	write_or_die(buf, 1);

	/* save size of long */
	buf[0] = sizeof(long);
	write_or_die(buf, 1);

	/* save page_size */
	page_size = sysconf(_SC_PAGESIZE);
	write_or_die(&page_size, 4);
	}

	struct tracing_data tracing_data_get(struct list_head pattrs,
	int fd, bool temp)
	{
	struct tracepoint_path *tps;
	struct tracing_data *tdata;

	output_fd = fd;

	tps = get_tracepoints_path(pattrs);
	if (!tps)
	return NULL;

	tdata = malloc_or_die(sizeof(*tdata));
	tdata->temp = temp;
	tdata->size = 0;

	if (temp) {
	int temp_fd;

	snprintf(tdata->temp_file, sizeof(tdata->temp_file),
	"/tmp/perf-XXXXXX");
	if (!mkstemp(tdata->temp_file))
	die("Can't make temp file");

	temp_fd = open(tdata->temp_file, O_RDWR);
	if (temp_fd < 0)
	die("Can't read '%s'", tdata->temp_file);

	/*
	* Set the temp file the default output, so all the
	* tracing data are stored into it.
	*/
	output_fd = temp_fd;
	}

	tracing_data_header();
	read_header_files();
	read_ftrace_files(tps);
	read_event_files(tps);
	read_proc_kallsyms();
	read_ftrace_printk();

	/*
	* All tracing data are stored by now, we can restore
	* the default output file in case we used temp file.
	*/
	if (temp) {
	tdata->size = lseek(output_fd, 0, SEEK_CUR);
	close(output_fd);
	output_fd = fd;
	}

	put_tracepoints_path(tps);
	return tdata;
	}

	void tracing_data_put(struct tracing_data *tdata)
	{
	if (tdata->temp) {
	record_file(tdata->temp_file, 0);
	unlink(tdata->temp_file);
	}

	free(tdata);
	}

	int read_tracing_data(int fd, struct list_head *pattrs)
	{
	struct tracing_data *tdata;

	/*
	* We work over the real file, so we can write data
	* directly, no temp file is needed.
	*/
	tdata = tracing_data_get(pattrs, fd, false);
	if (!tdata)
	return -ENOMEM;

	tracing_data_put(tdata);
	return 0;
	}