perf tools: Add trace event debugfs IO handler

Add util/trace-event-info.c which handles ftrace file IO from
debugfs and provides general helpers to fetch/save ftrace
events informations.

This file is a rename of the trace-cmd.c file from the
trace-cmd tools, written by Steven Rostedt and Josh Triplett,
originated from the git tree:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git

This is a perf tools integration.

For now, ftrace events information is saved in a separate file
than the standard perf.data

[fweisbec@gmail.com: various changes for perf tools integration]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Jon Masters <jonathan@jonmasters.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Zhaolei <zhaolei@cn.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jiaying Zhang <jiayingz@google.com>
Cc: Anton Blanchard <anton@samba.org>
LKML-Reference: <1250518688-7207-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 491 insertions, 0 deletions

diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
new file mode 100644
index 000000000000..78adff189bba
--- /dev/null
+++ b/tools/perf/util/trace-event-info.c
@@ -0,0 +1,491 @@
+/*
+ * 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
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#define _GNU_SOURCE
+#include <dirent.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 <ctype.h>
+#include <errno.h>
+
+#include "trace-event.h"
+
+
+#define VERSION "0.5"
+
+#define _STR(x) #x
+#define STR(x) _STR(x)
+#define MAX_PATH 256
+
+#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;
+};
+
+
+
+static void die(const char *fmt, ...)
+{
+	va_list ap;
+	int ret = errno;
+
+	if (errno)
+		perror("trace-cmd");
+	else
+		ret = -1;
+
+	va_start(ap, fmt);
+	fprintf(stderr, "  ");
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	fprintf(stderr, "\n");
+	exit(ret);
+}
+
+void *malloc_or_die(unsigned int size)
+{
+	void *data;
+
+	data = malloc(size);
+	if (!data)
+		die("malloc");
+	return data;
+}
+
+static const char *find_debugfs(void)
+{
+	static char debugfs[MAX_PATH+1];
+	static int debugfs_found;
+	char type[100];
+	FILE *fp;
+
+	if (debugfs_found)
+		return debugfs;
+
+	if ((fp = fopen("/proc/mounts","r")) == NULL)
+		die("Can't open /proc/mounts for read");
+
+	while (fscanf(fp, "%*s %"
+		      STR(MAX_PATH)
+		      "s %99s %*s %*d %*d\n",
+		      debugfs, type) == 2) {
+		if (strcmp(type, "debugfs") == 0)
+			break;
+	}
+	fclose(fp);
+
+	if (strcmp(type, "debugfs") != 0)
+		die("debugfs not mounted, please mount");
+
+	debugfs_found = 1;
+
+	return debugfs;
+}
+
+/*
+ * 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 write_or_die(const void *buf, size_t len)
+{
+	int ret;
+
+	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 *)str;
+	return *ptr == 0x01020304;
+}
+
+static unsigned long long copy_file_fd(int fd)
+{
+	unsigned long long size = 0;
+	char buf[BUFSIZ];
+	int r;
+
+	do {
+		r = read(fd, buf, BUFSIZ);
+		if (r > 0) {
+			size += r;
+			write_or_die(buf, r);
+		}
+	} while (r > 0);
+
+	return size;
+}
+
+static unsigned long long copy_file(const char *file)
+{
+	unsigned long long size = 0;
+	int fd;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		die("Can't read '%s'", file);
+	size = copy_file_fd(fd);
+	close(fd);
+
+	return size;
+}
+
+static unsigned long get_size_fd(int fd)
+{
+	unsigned long long size = 0;
+	char buf[BUFSIZ];
+	int r;
+
+	do {
+		r = read(fd, buf, BUFSIZ);
+		if (r > 0)
+			size += r;
+	} while (r > 0);
+
+	lseek(fd, 0, SEEK_SET);
+
+	return size;
+}
+
+static unsigned long get_size(const char *file)
+{
+	unsigned long long size = 0;
+	int fd;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		die("Can't read '%s'", file);
+	size = get_size_fd(fd);
+	close(fd);
+
+	return size;
+}
+
+static void read_header_files(void)
+{
+	unsigned long long size, check_size;
+	char *path;
+	int fd;
+
+	path = get_tracing_file("events/header_page");
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		die("can't read '%s'", path);
+
+	/* unfortunately, you can not stat debugfs files for size */
+	size = get_size_fd(fd);
+
+	write_or_die("header_page", 12);
+	write_or_die(&size, 8);
+	check_size = copy_file_fd(fd);
+	if (size != check_size)
+		die("wrong size for '%s' size=%lld read=%lld",
+		    path, size, check_size);
+	put_tracing_file(path);
+
+	path = get_tracing_file("events/header_event");
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		die("can't read '%s'", path);
+
+	size = get_size_fd(fd);
+
+	write_or_die("header_event", 13);
+	write_or_die(&size, 8);
+	check_size = copy_file_fd(fd);
+	if (size != check_size)
+		die("wrong size for '%s'", path);
+	put_tracing_file(path);
+}
+
+static void copy_event_system(const char *sys)
+{
+	unsigned long long size, check_size;
+	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 (strcmp(dent->d_name, ".") == 0 ||
+		    strcmp(dent->d_name, "..") == 0)
+			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 (strcmp(dent->d_name, ".") == 0 ||
+		    strcmp(dent->d_name, "..") == 0)
+			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) {
+			/* unfortunately, you can not stat debugfs files for size */
+			size = get_size(format);
+			write_or_die(&size, 8);
+			check_size = copy_file(format);
+			if (size != check_size)
+				die("error in size of file '%s'", format);
+		}
+
+		free(format);
+	}
+}
+
+static void read_ftrace_files(void)
+{
+	char *path;
+
+	path = get_tracing_file("events/ftrace");
+
+	copy_event_system(path);
+
+	put_tracing_file(path);
+}
+
+static void read_event_files(void)
+{
+	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 (strcmp(dent->d_name, ".") == 0 ||
+		    strcmp(dent->d_name, "..") == 0 ||
+		    strcmp(dent->d_name, "ftrace") == 0)
+			continue;
+		sys = malloc_or_die(strlen(path) + strlen(dent->d_name) + 2);
+		sprintf(sys, "%s/%s", path, dent->d_name);
+		ret = stat(sys, &st);
+		free(sys);
+		if (ret < 0)
+			continue;
+		if (S_ISDIR(st.st_mode))
+			count++;
+	}
+
+	write_or_die(&count, 4);
+
+	rewinddir(dir);
+	while ((dent = readdir(dir))) {
+		if (strcmp(dent->d_name, ".") == 0 ||
+		    strcmp(dent->d_name, "..") == 0 ||
+		    strcmp(dent->d_name, "ftrace") == 0)
+			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) {
+			if (S_ISDIR(st.st_mode)) {
+				write_or_die(dent->d_name, strlen(dent->d_name) + 1);
+				copy_event_system(sys);
+			}
+		}
+		free(sys);
+	}
+
+	put_tracing_file(path);
+}
+
+static void read_proc_kallsyms(void)
+{
+	unsigned int size, check_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;
+	}
+	size = get_size(path);
+	write_or_die(&size, 4);
+	check_size = copy_file(path);
+	if (size != check_size)
+		die("error in size of file '%s'", path);
+
+}
+
+static void read_ftrace_printk(void)
+{
+	unsigned int size, check_size;
+	const 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);
+		return;
+	}
+	size = get_size(path);
+	write_or_die(&size, 4);
+	check_size = copy_file(path);
+	if (size != check_size)
+		die("error in size of file '%s'", path);
+
+}
+
+void read_tracing_data(void)
+{
+	char buf[BUFSIZ];
+
+	output_fd = open(output_file, O_WRONLY | O_CREAT | O_TRUNC | O_LARGEFILE, 0644);
+	if (output_fd < 0)
+		die("creating file '%s'", output_file);
+
+	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 = getpagesize();
+	write_or_die(&page_size, 4);
+
+	read_header_files();
+	read_ftrace_files();
+	read_event_files();
+	read_proc_kallsyms();
+	read_ftrace_printk();
+}