swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 44549e8f5eea4e0a41b487b63e616cb089922b99 authored by Linus Torvalds on 08 May 2016, 21:38:32 UTC
Linux 4.6-rc7
Linux 4.6-rc7
Tip revision: 44549e8
trace-event-read.c
/*
* Copyright (C) 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 <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 <sys/mman.h>
#include <pthread.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "../perf.h"
#include "util.h"
#include "trace-event.h"
#include "debug.h"
static int input_fd;
static ssize_t trace_data_size;
static bool repipe;
static int __do_read(int fd, void *buf, int size)
{
int rsize = size;
while (size) {
int ret = read(fd, buf, size);
if (ret <= 0)
return -1;
if (repipe) {
int retw = write(STDOUT_FILENO, buf, ret);
if (retw <= 0 || retw != ret) {
pr_debug("repiping input file");
return -1;
}
}
size -= ret;
buf += ret;
}
return rsize;
}
static int do_read(void *data, int size)
{
int r;
r = __do_read(input_fd, data, size);
if (r <= 0) {
pr_debug("reading input file (size expected=%d received=%d)",
size, r);
return -1;
}
trace_data_size += r;
return r;
}
/* If it fails, the next read will report it */
static void skip(int size)
{
char buf[BUFSIZ];
int r;
while (size) {
r = size > BUFSIZ ? BUFSIZ : size;
do_read(buf, r);
size -= r;
};
}
static unsigned int read4(struct pevent *pevent)
{
unsigned int data;
if (do_read(&data, 4) < 0)
return 0;
return __data2host4(pevent, data);
}
static unsigned long long read8(struct pevent *pevent)
{
unsigned long long data;
if (do_read(&data, 8) < 0)
return 0;
return __data2host8(pevent, data);
}
static char *read_string(void)
{
char buf[BUFSIZ];
char *str = NULL;
int size = 0;
off_t r;
char c;
for (;;) {
r = read(input_fd, &c, 1);
if (r < 0) {
pr_debug("reading input file");
goto out;
}
if (!r) {
pr_debug("no data");
goto out;
}
if (repipe) {
int retw = write(STDOUT_FILENO, &c, 1);
if (retw <= 0 || retw != r) {
pr_debug("repiping input file string");
goto out;
}
}
buf[size++] = c;
if (!c)
break;
}
trace_data_size += size;
str = malloc(size);
if (str)
memcpy(str, buf, size);
out:
return str;
}
static int read_proc_kallsyms(struct pevent *pevent)
{
unsigned int size;
size = read4(pevent);
if (!size)
return 0;
/*
* Just skip it, now that we configure libtraceevent to use the
* tools/perf/ symbol resolver.
*
* We need to skip it so that we can continue parsing old perf.data
* files, that contains this /proc/kallsyms payload.
*
* Newer perf.data files will have just the 4-bytes zeros "kallsyms
* payload", so that older tools can continue reading it and interpret
* it as "no kallsyms payload is present".
*/
lseek(input_fd, size, SEEK_CUR);
trace_data_size += size;
return 0;
}
static int read_ftrace_printk(struct pevent *pevent)
{
unsigned int size;
char *buf;
/* it can have 0 size */
size = read4(pevent);
if (!size)
return 0;
buf = malloc(size);
if (buf == NULL)
return -1;
if (do_read(buf, size) < 0) {
free(buf);
return -1;
}
parse_ftrace_printk(pevent, buf, size);
free(buf);
return 0;
}
static int read_header_files(struct pevent *pevent)
{
unsigned long long size;
char *header_page;
char buf[BUFSIZ];
int ret = 0;
if (do_read(buf, 12) < 0)
return -1;
if (memcmp(buf, "header_page", 12) != 0) {
pr_debug("did not read header page");
return -1;
}
size = read8(pevent);
header_page = malloc(size);
if (header_page == NULL)
return -1;
if (do_read(header_page, size) < 0) {
pr_debug("did not read header page");
free(header_page);
return -1;
}
if (!pevent_parse_header_page(pevent, header_page, size,
pevent_get_long_size(pevent))) {
/*
* The commit field in the page is of type long,
* use that instead, since it represents the kernel.
*/
pevent_set_long_size(pevent, pevent->header_page_size_size);
}
free(header_page);
if (do_read(buf, 13) < 0)
return -1;
if (memcmp(buf, "header_event", 13) != 0) {
pr_debug("did not read header event");
return -1;
}
size = read8(pevent);
skip(size);
return ret;
}
static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
{
char *buf;
buf = malloc(size);
if (buf == NULL)
return -1;
if (do_read(buf, size) < 0) {
free(buf);
return -1;
}
parse_ftrace_file(pevent, buf, size);
free(buf);
return 0;
}
static int read_event_file(struct pevent *pevent, char *sys,
unsigned long long size)
{
char *buf;
buf = malloc(size);
if (buf == NULL)
return -1;
if (do_read(buf, size) < 0) {
free(buf);
return -1;
}
parse_event_file(pevent, buf, size, sys);
free(buf);
return 0;
}
static int read_ftrace_files(struct pevent *pevent)
{
unsigned long long size;
int count;
int i;
int ret;
count = read4(pevent);
for (i = 0; i < count; i++) {
size = read8(pevent);
ret = read_ftrace_file(pevent, size);
if (ret)
return ret;
}
return 0;
}
static int read_event_files(struct pevent *pevent)
{
unsigned long long size;
char *sys;
int systems;
int count;
int i,x;
int ret;
systems = read4(pevent);
for (i = 0; i < systems; i++) {
sys = read_string();
if (sys == NULL)
return -1;
count = read4(pevent);
for (x=0; x < count; x++) {
size = read8(pevent);
ret = read_event_file(pevent, sys, size);
if (ret)
return ret;
}
}
return 0;
}
ssize_t trace_report(int fd, struct trace_event *tevent, bool __repipe)
{
char buf[BUFSIZ];
char test[] = { 23, 8, 68 };
char *version;
int show_version = 0;
int show_funcs = 0;
int show_printk = 0;
ssize_t size = -1;
int file_bigendian;
int host_bigendian;
int file_long_size;
int file_page_size;
struct pevent *pevent = NULL;
int err;
repipe = __repipe;
input_fd = fd;
if (do_read(buf, 3) < 0)
return -1;
if (memcmp(buf, test, 3) != 0) {
pr_debug("no trace data in the file");
return -1;
}
if (do_read(buf, 7) < 0)
return -1;
if (memcmp(buf, "tracing", 7) != 0) {
pr_debug("not a trace file (missing 'tracing' tag)");
return -1;
}
version = read_string();
if (version == NULL)
return -1;
if (show_version)
printf("version = %s\n", version);
free(version);
if (do_read(buf, 1) < 0)
return -1;
file_bigendian = buf[0];
host_bigendian = bigendian();
if (trace_event__init(tevent)) {
pr_debug("trace_event__init failed");
goto out;
}
pevent = tevent->pevent;
pevent_set_flag(pevent, PEVENT_NSEC_OUTPUT);
pevent_set_file_bigendian(pevent, file_bigendian);
pevent_set_host_bigendian(pevent, host_bigendian);
if (do_read(buf, 1) < 0)
goto out;
file_long_size = buf[0];
file_page_size = read4(pevent);
if (!file_page_size)
goto out;
pevent_set_long_size(pevent, file_long_size);
pevent_set_page_size(pevent, file_page_size);
err = read_header_files(pevent);
if (err)
goto out;
err = read_ftrace_files(pevent);
if (err)
goto out;
err = read_event_files(pevent);
if (err)
goto out;
err = read_proc_kallsyms(pevent);
if (err)
goto out;
err = read_ftrace_printk(pevent);
if (err)
goto out;
size = trace_data_size;
repipe = false;
if (show_funcs) {
pevent_print_funcs(pevent);
} else if (show_printk) {
pevent_print_printk(pevent);
}
pevent = NULL;
out:
if (pevent)
trace_event__cleanup(tevent);
return size;
}