// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2008,2009, Steven Rostedt <[email protected]>
*/
#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 <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <stdbool.h>
#include <linux/list.h>
#include <linux/kernel.h>
#include <linux/zalloc.h>
#include <internal/lib.h> // page_size
#include <sys/param.h>
#include "trace-event.h"
#include "tracepoint.h"
#include <api/fs/tracing_path.h>
#include "evsel.h"
#include "debug.h"
#include "util.h"
#define VERSION "0.6"
#define MAX_EVENT_LENGTH 512
static int output_fd;
struct tracepoint_path {
char *system;
char *name;
struct tracepoint_path *next;
};
/* unfortunately, you can not stat debugfs or proc files for size */
static int record_file(const char *file, ssize_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;
int err = -EIO;
fd = open(file, O_RDONLY);
if (fd < 0) {
pr_debug("Can't read '%s'", file);
return -errno;
}
/* put in zeros for file size, then fill true size later */
if (hdr_sz) {
if (write(output_fd, &size, hdr_sz) != hdr_sz)
goto out;
}
do {
r = read(fd, buf, BUFSIZ);
if (r > 0) {
size += r;
if (write(output_fd, buf, r) != r)
goto out;
}
} while (r > 0);
/* ugh, handle big-endian hdr_size == 4 */
sizep = (char*)&size;
if (host_is_bigendian())
sizep += sizeof(u64) - hdr_sz;
if (hdr_sz && pwrite(output_fd, sizep, hdr_sz, hdr_pos) < 0) {
pr_debug("writing file size failed\n");
goto out;
}
err = 0;
out:
close(fd);
return err;
}
static int record_header_files(void)
{
char *path = get_events_file("header_page");
struct stat st;
int err = -EIO;
if (!path) {
pr_debug("can't get tracing/events/header_page");
return -ENOMEM;
}
if (stat(path, &st) < 0) {
pr_debug("can't read '%s'", path);
goto out;
}
if (write(output_fd, "header_page", 12) != 12) {
pr_debug("can't write header_page\n");
goto out;
}
if (record_file(path, 8) < 0) {
pr_debug("can't record header_page file\n");
goto out;
}
put_events_file(path);
path = get_events_file("header_event");
if (!path) {
pr_debug("can't get tracing/events/header_event");
err = -ENOMEM;
goto out;
}
if (stat(path, &st) < 0) {
pr_debug("can't read '%s'", path);
goto out;
}
if (write(output_fd, "header_event", 13) != 13) {
pr_debug("can't write header_event\n");
goto out;
}
if (record_file(path, 8) < 0) {
pr_debug("can't record header_event file\n");
goto out;
}
err = 0;
out:
put_events_file(path);
return err;
}
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;
}
#define for_each_event_tps(dir, dent, tps) \
while ((dent = readdir(dir))) \
if (dent->d_type == DT_DIR && \
(strcmp(dent->d_name, ".")) && \
(strcmp(dent->d_name, ".."))) \
static int 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;
int err;
dir = opendir(sys);
if (!dir) {
pr_debug("can't read directory '%s'", sys);
return -errno;
}
for_each_event_tps(dir, dent, tps) {
if (!name_in_tp_list(dent->d_name, tps))
continue;
if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
err = -ENOMEM;
goto out;
}
ret = stat(format, &st);
free(format);
if (ret < 0)
continue;
count++;
}
if (write(output_fd, &count, 4) != 4) {
err = -EIO;
pr_debug("can't write count\n");
goto out;
}
rewinddir(dir);
for_each_event_tps(dir, dent, tps) {
if (!name_in_tp_list(dent->d_name, tps))
continue;
if (asprintf(&format, "%s/%s/format", sys, dent->d_name) < 0) {
err = -ENOMEM;
goto out;
}
ret = stat(format, &st);
if (ret >= 0) {
err = record_file(format, 8);
if (err) {
free(format);
goto out;
}
}
free(format);
}
err = 0;
out:
closedir(dir);
return err;
}
static int record_ftrace_files(struct tracepoint_path *tps)
{
char *path;
int ret;
path = get_events_file("ftrace");
if (!path) {
pr_debug("can't get tracing/events/ftrace");
return -ENOMEM;
}
ret = copy_event_system(path, tps);
put_tracing_file(path);
return ret;
}
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 int record_event_files(struct tracepoint_path *tps)
{
struct dirent *dent;
struct stat st;
char *path;
char *sys;
DIR *dir;
int count = 0;
int ret;
int err;
path = get_tracing_file("events");
if (!path) {
pr_debug("can't get tracing/events");
return -ENOMEM;
}
dir = opendir(path);
if (!dir) {
err = -errno;
pr_debug("can't read directory '%s'", path);
goto out;
}
for_each_event_tps(dir, dent, tps) {
if (strcmp(dent->d_name, "ftrace") == 0 ||
!system_in_tp_list(dent->d_name, tps))
continue;
count++;
}
if (write(output_fd, &count, 4) != 4) {
err = -EIO;
pr_debug("can't write count\n");
goto out;
}
rewinddir(dir);
for_each_event_tps(dir, dent, tps) {
if (strcmp(dent->d_name, "ftrace") == 0 ||
!system_in_tp_list(dent->d_name, tps))
continue;
if (asprintf(&sys, "%s/%s", path, dent->d_name) < 0) {
err = -ENOMEM;
goto out;
}
ret = stat(sys, &st);
if (ret >= 0) {
ssize_t size = strlen(dent->d_name) + 1;
if (write(output_fd, dent->d_name, size) != size ||
copy_event_system(sys, tps) < 0) {
err = -EIO;
free(sys);
goto out;
}
}
free(sys);
}
err = 0;
out:
if (dir)
closedir(dir);
put_tracing_file(path);
return err;
}
static int record_proc_kallsyms(void)
{
unsigned long long size = 0;
/*
* Just to keep older perf.data file parsers happy, record a zero
* sized kallsyms file, i.e. do the same thing that was done when
* /proc/kallsyms (or something specified via --kallsyms, in a
* different path) couldn't be read.
*/
return write(output_fd, &size, 4) != 4 ? -EIO : 0;
}
static int record_ftrace_printk(void)
{
unsigned int size;
char *path;
struct stat st;
int ret, err = 0;
path = get_tracing_file("printk_formats");
if (!path) {
pr_debug("can't get tracing/printk_formats");
return -ENOMEM;
}
ret = stat(path, &st);
if (ret < 0) {
/* not found */
size = 0;
if (write(output_fd, &size, 4) != 4)
err = -EIO;
goto out;
}
err = record_file(path, 4);
out:
put_tracing_file(path);
return err;
}
static int record_saved_cmdline(void)
{
unsigned long long size;
char *path;
struct stat st;
int ret, err = 0;
path = get_tracing_file("saved_cmdlines");
if (!path) {
pr_debug("can't get tracing/saved_cmdline");
return -ENOMEM;
}
ret = stat(path, &st);
if (ret < 0) {
/* not found */
size = 0;
if (write(output_fd, &size, 8) != 8)
err = -EIO;
goto out;
}
err = record_file(path, 8);
out:
put_tracing_file(path);
return err;
}
static void
put_tracepoints_path(struct tracepoint_path *tps)
{
while (tps) {
struct tracepoint_path *t = tps;
tps = tps->next;
zfree(&t->name);
zfree(&t->system);
free(t);
}
}
static struct tracepoint_path *tracepoint_id_to_path(u64 config)
{
struct tracepoint_path *path = NULL;
DIR *sys_dir, *evt_dir;
struct dirent *sys_dirent, *evt_dirent;
char id_buf[24];
int fd;
u64 id;
char evt_path[MAXPATHLEN];
char *dir_path;
sys_dir = tracing_events__opendir();
if (!sys_dir)
return NULL;
for_each_subsystem(sys_dir, sys_dirent) {
dir_path = get_events_file(sys_dirent->d_name);
if (!dir_path)
continue;
evt_dir = opendir(dir_path);
if (!evt_dir)
goto next;
for_each_event(dir_path, evt_dir, evt_dirent) {
scnprintf(evt_path, MAXPATHLEN, "%s/%s/id", dir_path,
evt_dirent->d_name);
fd = open(evt_path, O_RDONLY);
if (fd < 0)
continue;
if (read(fd, id_buf, sizeof(id_buf)) < 0) {
close(fd);
continue;
}
close(fd);
id = atoll(id_buf);
if (id == config) {
put_events_file(dir_path);
closedir(evt_dir);
closedir(sys_dir);
path = zalloc(sizeof(*path));
if (!path)
return NULL;
if (asprintf(&path->system, "%.*s",
MAX_EVENT_LENGTH, sys_dirent->d_name) < 0) {
free(path);
return NULL;
}
if (asprintf(&path->name, "%.*s",
MAX_EVENT_LENGTH, evt_dirent->d_name) < 0) {
zfree(&path->system);
free(path);
return NULL;
}
return path;
}
}
closedir(evt_dir);
next:
put_events_file(dir_path);
}
closedir(sys_dir);
return NULL;
}
char *tracepoint_id_to_name(u64 config)
{
struct tracepoint_path *path = tracepoint_id_to_path(config);
char *buf = NULL;
if (path && asprintf(&buf, "%s:%s", path->system, path->name) < 0)
buf = NULL;
put_tracepoints_path(path);
return buf;
}
static struct tracepoint_path *tracepoint_name_to_path(const char *name)
{
struct tracepoint_path *path = zalloc(sizeof(*path));
char *str = strchr(name, ':');
if (path == NULL || str == NULL) {
free(path);
return NULL;
}
path->system = strndup(name, str - name);
path->name = strdup(str+1);
if (path->system == NULL || path->name == NULL) {
zfree(&path->system);
zfree(&path->name);
zfree(&path);
}
return path;
}
static struct tracepoint_path *
get_tracepoints_path(struct list_head *pattrs)
{
struct tracepoint_path path, *ppath = &path;
struct evsel *pos;
int nr_tracepoints = 0;
list_for_each_entry(pos, pattrs, core.node) {
if (pos->core.attr.type != PERF_TYPE_TRACEPOINT)
continue;
++nr_tracepoints;
if (pos->name) {
ppath->next = tracepoint_name_to_path(pos->name);
if (ppath->next)
goto next;
if (strchr(pos->name, ':') == NULL)
goto try_id;
goto error;
}
try_id:
ppath->next = tracepoint_id_to_path(pos->core.attr.config);
if (!ppath->next) {
error:
pr_debug("No memory to alloc tracepoints list\n");
put_tracepoints_path(path.next);
return NULL;
}
next:
ppath = ppath->next;
}
return nr_tracepoints > 0 ? path.next : NULL;
}
bool have_tracepoints(struct list_head *pattrs)
{
struct evsel *pos;
list_for_each_entry(pos, pattrs, core.node)
if (pos->core.attr.type == PERF_TYPE_TRACEPOINT)
return true;
return false;
}
static int tracing_data_header(void)
{
char buf[20];
ssize_t size;
/* just guessing this is someone's birthday.. ;) */
buf[0] = 23;
buf[1] = 8;
buf[2] = 68;
memcpy(buf + 3, "tracing", 7);
if (write(output_fd, buf, 10) != 10)
return -1;
size = strlen(VERSION) + 1;
if (write(output_fd, VERSION, size) != size)
return -1;
/* save endian */
if (host_is_bigendian())
buf[0] = 1;
else
buf[0] = 0;
if (write(output_fd, buf, 1) != 1)
return -1;
/* save size of long */
buf[0] = sizeof(long);
if (write(output_fd, buf, 1) != 1)
return -1;
/* save page_size */
if (write(output_fd, &page_size, 4) != 4)
return -1;
return 0;
}
struct tracing_data *tracing_data_get(struct list_head *pattrs,
int fd, bool temp)
{
struct tracepoint_path *tps;
struct tracing_data *tdata;
int err;
output_fd = fd;
tps = get_tracepoints_path(pattrs);
if (!tps)
return NULL;
tdata = malloc(sizeof(*tdata));
if (!tdata)
return NULL;
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)) {
pr_debug("Can't make temp file");
free(tdata);
return NULL;
}
temp_fd = open(tdata->temp_file, O_RDWR);
if (temp_fd < 0) {
pr_debug("Can't read '%s'", tdata->temp_file);
free(tdata);
return NULL;
}
/*
* Set the temp file the default output, so all the
* tracing data are stored into it.
*/
output_fd = temp_fd;
}
err = tracing_data_header();
if (err)
goto out;
err = record_header_files();
if (err)
goto out;
err = record_ftrace_files(tps);
if (err)
goto out;
err = record_event_files(tps);
if (err)
goto out;
err = record_proc_kallsyms();
if (err)
goto out;
err = record_ftrace_printk();
if (err)
goto out;
err = record_saved_cmdline();
out:
/*
* 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;
}
if (err)
zfree(&tdata);
put_tracepoints_path(tps);
return tdata;
}
int tracing_data_put(struct tracing_data *tdata)
{
int err = 0;
if (tdata->temp) {
err = record_file(tdata->temp_file, 0);
unlink(tdata->temp_file);
}
free(tdata);
return err;
}
int read_tracing_data(int fd, struct list_head *pattrs)
{
int err;
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;
err = tracing_data_put(tdata);
return err;
}
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