swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Tip revision: e22ce8eb631bdc47a4a4ea7ecf4e4ba499db4f93 authored by Linus Torvalds on 22 August 2021, 21:24:56 UTC
Linux 5.14-rc7
Linux 5.14-rc7
Tip revision: e22ce8e
data.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/zalloc.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <asm/bug.h>
#include <dirent.h>
#include "data.h"
#include "util.h" // rm_rf_perf_data()
#include "debug.h"
#include "header.h"
#include <internal/lib.h>
static void close_dir(struct perf_data_file *files, int nr)
{
while (--nr >= 0) {
close(files[nr].fd);
zfree(&files[nr].path);
}
free(files);
}
void perf_data__close_dir(struct perf_data *data)
{
close_dir(data->dir.files, data->dir.nr);
}
int perf_data__create_dir(struct perf_data *data, int nr)
{
struct perf_data_file *files = NULL;
int i, ret;
if (WARN_ON(!data->is_dir))
return -EINVAL;
files = zalloc(nr * sizeof(*files));
if (!files)
return -ENOMEM;
data->dir.version = PERF_DIR_VERSION;
data->dir.files = files;
data->dir.nr = nr;
for (i = 0; i < nr; i++) {
struct perf_data_file *file = &files[i];
ret = asprintf(&file->path, "%s/data.%d", data->path, i);
if (ret < 0)
goto out_err;
ret = open(file->path, O_RDWR|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
if (ret < 0)
goto out_err;
file->fd = ret;
}
return 0;
out_err:
close_dir(files, i);
return ret;
}
int perf_data__open_dir(struct perf_data *data)
{
struct perf_data_file *files = NULL;
struct dirent *dent;
int ret = -1;
DIR *dir;
int nr = 0;
/*
* Directory containing a single regular perf data file which is already
* open, means there is nothing more to do here.
*/
if (perf_data__is_single_file(data))
return 0;
if (WARN_ON(!data->is_dir))
return -EINVAL;
/* The version is provided by DIR_FORMAT feature. */
if (WARN_ON(data->dir.version != PERF_DIR_VERSION))
return -1;
dir = opendir(data->path);
if (!dir)
return -EINVAL;
while ((dent = readdir(dir)) != NULL) {
struct perf_data_file *file;
char path[PATH_MAX];
struct stat st;
snprintf(path, sizeof(path), "%s/%s", data->path, dent->d_name);
if (stat(path, &st))
continue;
if (!S_ISREG(st.st_mode) || strncmp(dent->d_name, "data.", 5))
continue;
ret = -ENOMEM;
file = realloc(files, (nr + 1) * sizeof(*files));
if (!file)
goto out_err;
files = file;
file = &files[nr++];
file->path = strdup(path);
if (!file->path)
goto out_err;
ret = open(file->path, O_RDONLY);
if (ret < 0)
goto out_err;
file->fd = ret;
file->size = st.st_size;
}
if (!files)
return -EINVAL;
data->dir.files = files;
data->dir.nr = nr;
return 0;
out_err:
close_dir(files, nr);
return ret;
}
int perf_data__update_dir(struct perf_data *data)
{
int i;
if (WARN_ON(!data->is_dir))
return -EINVAL;
for (i = 0; i < data->dir.nr; i++) {
struct perf_data_file *file = &data->dir.files[i];
struct stat st;
if (fstat(file->fd, &st))
return -1;
file->size = st.st_size;
}
return 0;
}
static bool check_pipe(struct perf_data *data)
{
struct stat st;
bool is_pipe = false;
int fd = perf_data__is_read(data) ?
STDIN_FILENO : STDOUT_FILENO;
if (!data->path) {
if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
is_pipe = true;
} else {
if (!strcmp(data->path, "-"))
is_pipe = true;
}
if (is_pipe) {
if (data->use_stdio) {
const char *mode;
mode = perf_data__is_read(data) ? "r" : "w";
data->file.fptr = fdopen(fd, mode);
if (data->file.fptr == NULL) {
data->file.fd = fd;
data->use_stdio = false;
}
} else {
data->file.fd = fd;
}
}
return data->is_pipe = is_pipe;
}
static int check_backup(struct perf_data *data)
{
struct stat st;
if (perf_data__is_read(data))
return 0;
if (!stat(data->path, &st) && st.st_size) {
char oldname[PATH_MAX];
int ret;
snprintf(oldname, sizeof(oldname), "%s.old",
data->path);
ret = rm_rf_perf_data(oldname);
if (ret) {
pr_err("Can't remove old data: %s (%s)\n",
ret == -2 ?
"Unknown file found" : strerror(errno),
oldname);
return -1;
}
if (rename(data->path, oldname)) {
pr_err("Can't move data: %s (%s to %s)\n",
strerror(errno),
data->path, oldname);
return -1;
}
}
return 0;
}
static bool is_dir(struct perf_data *data)
{
struct stat st;
if (stat(data->path, &st))
return false;
return (st.st_mode & S_IFMT) == S_IFDIR;
}
static int open_file_read(struct perf_data *data)
{
int flags = data->in_place_update ? O_RDWR : O_RDONLY;
struct stat st;
int fd;
char sbuf[STRERR_BUFSIZE];
fd = open(data->file.path, flags);
if (fd < 0) {
int err = errno;
pr_err("failed to open %s: %s", data->file.path,
str_error_r(err, sbuf, sizeof(sbuf)));
if (err == ENOENT && !strcmp(data->file.path, "perf.data"))
pr_err(" (try 'perf record' first)");
pr_err("\n");
return -err;
}
if (fstat(fd, &st) < 0)
goto out_close;
if (!data->force && st.st_uid && (st.st_uid != geteuid())) {
pr_err("File %s not owned by current user or root (use -f to override)\n",
data->file.path);
goto out_close;
}
if (!st.st_size) {
pr_info("zero-sized data (%s), nothing to do!\n",
data->file.path);
goto out_close;
}
data->file.size = st.st_size;
return fd;
out_close:
close(fd);
return -1;
}
static int open_file_write(struct perf_data *data)
{
int fd;
char sbuf[STRERR_BUFSIZE];
fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC,
S_IRUSR|S_IWUSR);
if (fd < 0)
pr_err("failed to open %s : %s\n", data->file.path,
str_error_r(errno, sbuf, sizeof(sbuf)));
return fd;
}
static int open_file(struct perf_data *data)
{
int fd;
fd = perf_data__is_read(data) ?
open_file_read(data) : open_file_write(data);
if (fd < 0) {
zfree(&data->file.path);
return -1;
}
data->file.fd = fd;
return 0;
}
static int open_file_dup(struct perf_data *data)
{
data->file.path = strdup(data->path);
if (!data->file.path)
return -ENOMEM;
return open_file(data);
}
static int open_dir(struct perf_data *data)
{
int ret;
/*
* So far we open only the header, so we can read the data version and
* layout.
*/
if (asprintf(&data->file.path, "%s/data", data->path) < 0)
return -1;
if (perf_data__is_write(data) &&
mkdir(data->path, S_IRWXU) < 0)
return -1;
ret = open_file(data);
/* Cleanup whatever we managed to create so far. */
if (ret && perf_data__is_write(data))
rm_rf_perf_data(data->path);
return ret;
}
int perf_data__open(struct perf_data *data)
{
if (check_pipe(data))
return 0;
/* currently it allows stdio for pipe only */
data->use_stdio = false;
if (!data->path)
data->path = "perf.data";
if (check_backup(data))
return -1;
if (perf_data__is_read(data))
data->is_dir = is_dir(data);
return perf_data__is_dir(data) ?
open_dir(data) : open_file_dup(data);
}
void perf_data__close(struct perf_data *data)
{
if (perf_data__is_dir(data))
perf_data__close_dir(data);
zfree(&data->file.path);
if (data->use_stdio)
fclose(data->file.fptr);
else
close(data->file.fd);
}
ssize_t perf_data__read(struct perf_data *data, void *buf, size_t size)
{
if (data->use_stdio) {
if (fread(buf, size, 1, data->file.fptr) == 1)
return size;
return feof(data->file.fptr) ? 0 : -1;
}
return readn(data->file.fd, buf, size);
}
ssize_t perf_data_file__write(struct perf_data_file *file,
void *buf, size_t size)
{
return writen(file->fd, buf, size);
}
ssize_t perf_data__write(struct perf_data *data,
void *buf, size_t size)
{
if (data->use_stdio) {
if (fwrite(buf, size, 1, data->file.fptr) == 1)
return size;
return -1;
}
return perf_data_file__write(&data->file, buf, size);
}
int perf_data__switch(struct perf_data *data,
const char *postfix,
size_t pos, bool at_exit,
char **new_filepath)
{
int ret;
if (check_pipe(data))
return -EINVAL;
if (perf_data__is_read(data))
return -EINVAL;
if (asprintf(new_filepath, "%s.%s", data->path, postfix) < 0)
return -ENOMEM;
/*
* Only fire a warning, don't return error, continue fill
* original file.
*/
if (rename(data->path, *new_filepath))
pr_warning("Failed to rename %s to %s\n", data->path, *new_filepath);
if (!at_exit) {
close(data->file.fd);
ret = perf_data__open(data);
if (ret < 0)
goto out;
if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) {
ret = -errno;
pr_debug("Failed to lseek to %zu: %s",
pos, strerror(errno));
goto out;
}
}
ret = data->file.fd;
out:
return ret;
}
unsigned long perf_data__size(struct perf_data *data)
{
u64 size = data->file.size;
int i;
if (perf_data__is_single_file(data))
return size;
for (i = 0; i < data->dir.nr; i++) {
struct perf_data_file *file = &data->dir.files[i];
size += file->size;
}
return size;
}
int perf_data__make_kcore_dir(struct perf_data *data, char *buf, size_t buf_sz)
{
int ret;
if (!data->is_dir)
return -1;
ret = snprintf(buf, buf_sz, "%s/kcore_dir", data->path);
if (ret < 0 || (size_t)ret >= buf_sz)
return -1;
return mkdir(buf, S_IRWXU);
}
char *perf_data__kallsyms_name(struct perf_data *data)
{
char *kallsyms_name;
struct stat st;
if (!data->is_dir)
return NULL;
if (asprintf(&kallsyms_name, "%s/kcore_dir/kallsyms", data->path) < 0)
return NULL;
if (stat(kallsyms_name, &st)) {
free(kallsyms_name);
return NULL;
}
return kallsyms_name;
}
bool is_perf_data(const char *path)
{
bool ret = false;
FILE *file;
u64 magic;
file = fopen(path, "r");
if (!file)
return false;
if (fread(&magic, 1, 8, file) < 8)
goto out;
ret = is_perf_magic(magic);
out:
fclose(file);
return ret;
}