// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* Minimal file system backend for holding eBPF maps and programs,
|
* used by bpf(2) object pinning.
|
*
|
* Authors:
|
*
|
* Daniel Borkmann <daniel@iogearbox.net>
|
*/
|
|
#include <linux/init.h>
|
#include <linux/magic.h>
|
#include <linux/major.h>
|
#include <linux/mount.h>
|
#include <linux/namei.h>
|
#include <linux/fs.h>
|
#include <linux/fs_context.h>
|
#include <linux/fs_parser.h>
|
#include <linux/kdev_t.h>
|
#include <linux/filter.h>
|
#include <linux/bpf.h>
|
#include <linux/bpf_trace.h>
|
#include "preload/bpf_preload.h"
|
|
enum bpf_type {
|
BPF_TYPE_UNSPEC = 0,
|
BPF_TYPE_PROG,
|
BPF_TYPE_MAP,
|
BPF_TYPE_LINK,
|
};
|
|
static void *bpf_any_get(void *raw, enum bpf_type type)
|
{
|
switch (type) {
|
case BPF_TYPE_PROG:
|
bpf_prog_inc(raw);
|
break;
|
case BPF_TYPE_MAP:
|
bpf_map_inc_with_uref(raw);
|
break;
|
case BPF_TYPE_LINK:
|
bpf_link_inc(raw);
|
break;
|
default:
|
WARN_ON_ONCE(1);
|
break;
|
}
|
|
return raw;
|
}
|
|
static void bpf_any_put(void *raw, enum bpf_type type)
|
{
|
switch (type) {
|
case BPF_TYPE_PROG:
|
bpf_prog_put(raw);
|
break;
|
case BPF_TYPE_MAP:
|
bpf_map_put_with_uref(raw);
|
break;
|
case BPF_TYPE_LINK:
|
bpf_link_put(raw);
|
break;
|
default:
|
WARN_ON_ONCE(1);
|
break;
|
}
|
}
|
|
static void *bpf_fd_probe_obj(u32 ufd, enum bpf_type *type)
|
{
|
void *raw;
|
|
raw = bpf_map_get_with_uref(ufd);
|
if (!IS_ERR(raw)) {
|
*type = BPF_TYPE_MAP;
|
return raw;
|
}
|
|
raw = bpf_prog_get(ufd);
|
if (!IS_ERR(raw)) {
|
*type = BPF_TYPE_PROG;
|
return raw;
|
}
|
|
raw = bpf_link_get_from_fd(ufd);
|
if (!IS_ERR(raw)) {
|
*type = BPF_TYPE_LINK;
|
return raw;
|
}
|
|
return ERR_PTR(-EINVAL);
|
}
|
|
static const struct inode_operations bpf_dir_iops;
|
|
static const struct inode_operations bpf_prog_iops = { };
|
static const struct inode_operations bpf_map_iops = { };
|
static const struct inode_operations bpf_link_iops = { };
|
|
static struct inode *bpf_get_inode(struct super_block *sb,
|
const struct inode *dir,
|
umode_t mode)
|
{
|
struct inode *inode;
|
|
switch (mode & S_IFMT) {
|
case S_IFDIR:
|
case S_IFREG:
|
case S_IFLNK:
|
break;
|
default:
|
return ERR_PTR(-EINVAL);
|
}
|
|
inode = new_inode(sb);
|
if (!inode)
|
return ERR_PTR(-ENOSPC);
|
|
inode->i_ino = get_next_ino();
|
inode->i_atime = current_time(inode);
|
inode->i_mtime = inode->i_atime;
|
inode->i_ctime = inode->i_atime;
|
|
inode_init_owner(inode, dir, mode);
|
|
return inode;
|
}
|
|
static int bpf_inode_type(const struct inode *inode, enum bpf_type *type)
|
{
|
*type = BPF_TYPE_UNSPEC;
|
if (inode->i_op == &bpf_prog_iops)
|
*type = BPF_TYPE_PROG;
|
else if (inode->i_op == &bpf_map_iops)
|
*type = BPF_TYPE_MAP;
|
else if (inode->i_op == &bpf_link_iops)
|
*type = BPF_TYPE_LINK;
|
else
|
return -EACCES;
|
|
return 0;
|
}
|
|
static void bpf_dentry_finalize(struct dentry *dentry, struct inode *inode,
|
struct inode *dir)
|
{
|
d_instantiate(dentry, inode);
|
dget(dentry);
|
|
dir->i_mtime = current_time(dir);
|
dir->i_ctime = dir->i_mtime;
|
}
|
|
static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
|
{
|
struct inode *inode;
|
|
inode = bpf_get_inode(dir->i_sb, dir, mode | S_IFDIR);
|
if (IS_ERR(inode))
|
return PTR_ERR(inode);
|
|
inode->i_op = &bpf_dir_iops;
|
inode->i_fop = &simple_dir_operations;
|
|
inc_nlink(inode);
|
inc_nlink(dir);
|
|
bpf_dentry_finalize(dentry, inode, dir);
|
return 0;
|
}
|
|
struct map_iter {
|
void *key;
|
bool done;
|
};
|
|
static struct map_iter *map_iter(struct seq_file *m)
|
{
|
return m->private;
|
}
|
|
static struct bpf_map *seq_file_to_map(struct seq_file *m)
|
{
|
return file_inode(m->file)->i_private;
|
}
|
|
static void map_iter_free(struct map_iter *iter)
|
{
|
if (iter) {
|
kfree(iter->key);
|
kfree(iter);
|
}
|
}
|
|
static struct map_iter *map_iter_alloc(struct bpf_map *map)
|
{
|
struct map_iter *iter;
|
|
iter = kzalloc(sizeof(*iter), GFP_KERNEL | __GFP_NOWARN);
|
if (!iter)
|
goto error;
|
|
iter->key = kzalloc(map->key_size, GFP_KERNEL | __GFP_NOWARN);
|
if (!iter->key)
|
goto error;
|
|
return iter;
|
|
error:
|
map_iter_free(iter);
|
return NULL;
|
}
|
|
static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
{
|
struct bpf_map *map = seq_file_to_map(m);
|
void *key = map_iter(m)->key;
|
void *prev_key;
|
|
(*pos)++;
|
if (map_iter(m)->done)
|
return NULL;
|
|
if (unlikely(v == SEQ_START_TOKEN))
|
prev_key = NULL;
|
else
|
prev_key = key;
|
|
rcu_read_lock();
|
if (map->ops->map_get_next_key(map, prev_key, key)) {
|
map_iter(m)->done = true;
|
key = NULL;
|
}
|
rcu_read_unlock();
|
return key;
|
}
|
|
static void *map_seq_start(struct seq_file *m, loff_t *pos)
|
{
|
if (map_iter(m)->done)
|
return NULL;
|
|
return *pos ? map_iter(m)->key : SEQ_START_TOKEN;
|
}
|
|
static void map_seq_stop(struct seq_file *m, void *v)
|
{
|
}
|
|
static int map_seq_show(struct seq_file *m, void *v)
|
{
|
struct bpf_map *map = seq_file_to_map(m);
|
void *key = map_iter(m)->key;
|
|
if (unlikely(v == SEQ_START_TOKEN)) {
|
seq_puts(m, "# WARNING!! The output is for debug purpose only\n");
|
seq_puts(m, "# WARNING!! The output format will change\n");
|
} else {
|
map->ops->map_seq_show_elem(map, key, m);
|
}
|
|
return 0;
|
}
|
|
static const struct seq_operations bpffs_map_seq_ops = {
|
.start = map_seq_start,
|
.next = map_seq_next,
|
.show = map_seq_show,
|
.stop = map_seq_stop,
|
};
|
|
static int bpffs_map_open(struct inode *inode, struct file *file)
|
{
|
struct bpf_map *map = inode->i_private;
|
struct map_iter *iter;
|
struct seq_file *m;
|
int err;
|
|
iter = map_iter_alloc(map);
|
if (!iter)
|
return -ENOMEM;
|
|
err = seq_open(file, &bpffs_map_seq_ops);
|
if (err) {
|
map_iter_free(iter);
|
return err;
|
}
|
|
m = file->private_data;
|
m->private = iter;
|
|
return 0;
|
}
|
|
static int bpffs_map_release(struct inode *inode, struct file *file)
|
{
|
struct seq_file *m = file->private_data;
|
|
map_iter_free(map_iter(m));
|
|
return seq_release(inode, file);
|
}
|
|
/* bpffs_map_fops should only implement the basic
|
* read operation for a BPF map. The purpose is to
|
* provide a simple user intuitive way to do
|
* "cat bpffs/pathto/a-pinned-map".
|
*
|
* Other operations (e.g. write, lookup...) should be realized by
|
* the userspace tools (e.g. bpftool) through the
|
* BPF_OBJ_GET_INFO_BY_FD and the map's lookup/update
|
* interface.
|
*/
|
static const struct file_operations bpffs_map_fops = {
|
.open = bpffs_map_open,
|
.read = seq_read,
|
.release = bpffs_map_release,
|
};
|
|
static int bpffs_obj_open(struct inode *inode, struct file *file)
|
{
|
return -EIO;
|
}
|
|
static const struct file_operations bpffs_obj_fops = {
|
.open = bpffs_obj_open,
|
};
|
|
static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw,
|
const struct inode_operations *iops,
|
const struct file_operations *fops)
|
{
|
struct inode *dir = dentry->d_parent->d_inode;
|
struct inode *inode = bpf_get_inode(dir->i_sb, dir, mode);
|
if (IS_ERR(inode))
|
return PTR_ERR(inode);
|
|
inode->i_op = iops;
|
inode->i_fop = fops;
|
inode->i_private = raw;
|
|
bpf_dentry_finalize(dentry, inode, dir);
|
return 0;
|
}
|
|
static int bpf_mkprog(struct dentry *dentry, umode_t mode, void *arg)
|
{
|
return bpf_mkobj_ops(dentry, mode, arg, &bpf_prog_iops,
|
&bpffs_obj_fops);
|
}
|
|
static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg)
|
{
|
struct bpf_map *map = arg;
|
|
return bpf_mkobj_ops(dentry, mode, arg, &bpf_map_iops,
|
bpf_map_support_seq_show(map) ?
|
&bpffs_map_fops : &bpffs_obj_fops);
|
}
|
|
static int bpf_mklink(struct dentry *dentry, umode_t mode, void *arg)
|
{
|
struct bpf_link *link = arg;
|
|
return bpf_mkobj_ops(dentry, mode, arg, &bpf_link_iops,
|
bpf_link_is_iter(link) ?
|
&bpf_iter_fops : &bpffs_obj_fops);
|
}
|
|
static struct dentry *
|
bpf_lookup(struct inode *dir, struct dentry *dentry, unsigned flags)
|
{
|
/* Dots in names (e.g. "/sys/fs/bpf/foo.bar") are reserved for future
|
* extensions. That allows popoulate_bpffs() create special files.
|
*/
|
if ((dir->i_mode & S_IALLUGO) &&
|
strchr(dentry->d_name.name, '.'))
|
return ERR_PTR(-EPERM);
|
|
return simple_lookup(dir, dentry, flags);
|
}
|
|
static int bpf_symlink(struct inode *dir, struct dentry *dentry,
|
const char *target)
|
{
|
char *link = kstrdup(target, GFP_USER | __GFP_NOWARN);
|
struct inode *inode;
|
|
if (!link)
|
return -ENOMEM;
|
|
inode = bpf_get_inode(dir->i_sb, dir, S_IRWXUGO | S_IFLNK);
|
if (IS_ERR(inode)) {
|
kfree(link);
|
return PTR_ERR(inode);
|
}
|
|
inode->i_op = &simple_symlink_inode_operations;
|
inode->i_link = link;
|
|
bpf_dentry_finalize(dentry, inode, dir);
|
return 0;
|
}
|
|
static const struct inode_operations bpf_dir_iops = {
|
.lookup = bpf_lookup,
|
.mkdir = bpf_mkdir,
|
.symlink = bpf_symlink,
|
.rmdir = simple_rmdir,
|
.rename = simple_rename,
|
.link = simple_link,
|
.unlink = simple_unlink,
|
};
|
|
/* pin iterator link into bpffs */
|
static int bpf_iter_link_pin_kernel(struct dentry *parent,
|
const char *name, struct bpf_link *link)
|
{
|
umode_t mode = S_IFREG | S_IRUSR;
|
struct dentry *dentry;
|
int ret;
|
|
inode_lock(parent->d_inode);
|
dentry = lookup_one_len(name, parent, strlen(name));
|
if (IS_ERR(dentry)) {
|
inode_unlock(parent->d_inode);
|
return PTR_ERR(dentry);
|
}
|
ret = bpf_mkobj_ops(dentry, mode, link, &bpf_link_iops,
|
&bpf_iter_fops);
|
dput(dentry);
|
inode_unlock(parent->d_inode);
|
return ret;
|
}
|
|
static int bpf_obj_do_pin(const char __user *pathname, void *raw,
|
enum bpf_type type)
|
{
|
struct dentry *dentry;
|
struct inode *dir;
|
struct path path;
|
umode_t mode;
|
int ret;
|
|
dentry = user_path_create(AT_FDCWD, pathname, &path, 0);
|
if (IS_ERR(dentry))
|
return PTR_ERR(dentry);
|
|
mode = S_IFREG | ((S_IRUSR | S_IWUSR) & ~current_umask());
|
|
ret = security_path_mknod(&path, dentry, mode, 0);
|
if (ret)
|
goto out;
|
|
dir = d_inode(path.dentry);
|
if (dir->i_op != &bpf_dir_iops) {
|
ret = -EPERM;
|
goto out;
|
}
|
|
switch (type) {
|
case BPF_TYPE_PROG:
|
ret = vfs_mkobj(dentry, mode, bpf_mkprog, raw);
|
break;
|
case BPF_TYPE_MAP:
|
ret = vfs_mkobj(dentry, mode, bpf_mkmap, raw);
|
break;
|
case BPF_TYPE_LINK:
|
ret = vfs_mkobj(dentry, mode, bpf_mklink, raw);
|
break;
|
default:
|
ret = -EPERM;
|
}
|
out:
|
done_path_create(&path, dentry);
|
return ret;
|
}
|
|
int bpf_obj_pin_user(u32 ufd, const char __user *pathname)
|
{
|
enum bpf_type type;
|
void *raw;
|
int ret;
|
|
raw = bpf_fd_probe_obj(ufd, &type);
|
if (IS_ERR(raw))
|
return PTR_ERR(raw);
|
|
ret = bpf_obj_do_pin(pathname, raw, type);
|
if (ret != 0)
|
bpf_any_put(raw, type);
|
|
return ret;
|
}
|
|
static void *bpf_obj_do_get(const char __user *pathname,
|
enum bpf_type *type, int flags)
|
{
|
struct inode *inode;
|
struct path path;
|
void *raw;
|
int ret;
|
|
ret = user_path_at(AT_FDCWD, pathname, LOOKUP_FOLLOW, &path);
|
if (ret)
|
return ERR_PTR(ret);
|
|
inode = d_backing_inode(path.dentry);
|
ret = inode_permission(inode, ACC_MODE(flags));
|
if (ret)
|
goto out;
|
|
ret = bpf_inode_type(inode, type);
|
if (ret)
|
goto out;
|
|
raw = bpf_any_get(inode->i_private, *type);
|
if (!IS_ERR(raw))
|
touch_atime(&path);
|
|
path_put(&path);
|
return raw;
|
out:
|
path_put(&path);
|
return ERR_PTR(ret);
|
}
|
|
int bpf_obj_get_user(const char __user *pathname, int flags)
|
{
|
enum bpf_type type = BPF_TYPE_UNSPEC;
|
int f_flags;
|
void *raw;
|
int ret;
|
|
f_flags = bpf_get_file_flag(flags);
|
if (f_flags < 0)
|
return f_flags;
|
|
raw = bpf_obj_do_get(pathname, &type, f_flags);
|
if (IS_ERR(raw))
|
return PTR_ERR(raw);
|
|
if (type == BPF_TYPE_PROG)
|
ret = bpf_prog_new_fd(raw);
|
else if (type == BPF_TYPE_MAP)
|
ret = bpf_map_new_fd(raw, f_flags);
|
else if (type == BPF_TYPE_LINK)
|
ret = (f_flags != O_RDWR) ? -EINVAL : bpf_link_new_fd(raw);
|
else
|
return -ENOENT;
|
|
if (ret < 0)
|
bpf_any_put(raw, type);
|
return ret;
|
}
|
|
static struct bpf_prog *__get_prog_inode(struct inode *inode, enum bpf_prog_type type)
|
{
|
struct bpf_prog *prog;
|
int ret = inode_permission(inode, MAY_READ);
|
if (ret)
|
return ERR_PTR(ret);
|
|
if (inode->i_op == &bpf_map_iops)
|
return ERR_PTR(-EINVAL);
|
if (inode->i_op == &bpf_link_iops)
|
return ERR_PTR(-EINVAL);
|
if (inode->i_op != &bpf_prog_iops)
|
return ERR_PTR(-EACCES);
|
|
prog = inode->i_private;
|
|
ret = security_bpf_prog(prog);
|
if (ret < 0)
|
return ERR_PTR(ret);
|
|
if (!bpf_prog_get_ok(prog, &type, false))
|
return ERR_PTR(-EINVAL);
|
|
bpf_prog_inc(prog);
|
return prog;
|
}
|
|
struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
|
{
|
struct bpf_prog *prog;
|
struct path path;
|
int ret = kern_path(name, LOOKUP_FOLLOW, &path);
|
if (ret)
|
return ERR_PTR(ret);
|
prog = __get_prog_inode(d_backing_inode(path.dentry), type);
|
if (!IS_ERR(prog))
|
touch_atime(&path);
|
path_put(&path);
|
return prog;
|
}
|
EXPORT_SYMBOL(bpf_prog_get_type_path);
|
|
/*
|
* Display the mount options in /proc/mounts.
|
*/
|
static int bpf_show_options(struct seq_file *m, struct dentry *root)
|
{
|
umode_t mode = d_inode(root)->i_mode & S_IALLUGO & ~S_ISVTX;
|
|
if (mode != S_IRWXUGO)
|
seq_printf(m, ",mode=%o", mode);
|
return 0;
|
}
|
|
static void bpf_free_inode(struct inode *inode)
|
{
|
enum bpf_type type;
|
|
if (S_ISLNK(inode->i_mode))
|
kfree(inode->i_link);
|
if (!bpf_inode_type(inode, &type))
|
bpf_any_put(inode->i_private, type);
|
free_inode_nonrcu(inode);
|
}
|
|
static const struct super_operations bpf_super_ops = {
|
.statfs = simple_statfs,
|
.drop_inode = generic_delete_inode,
|
.show_options = bpf_show_options,
|
.free_inode = bpf_free_inode,
|
};
|
|
enum {
|
OPT_MODE,
|
};
|
|
static const struct fs_parameter_spec bpf_fs_parameters[] = {
|
fsparam_u32oct ("mode", OPT_MODE),
|
{}
|
};
|
|
struct bpf_mount_opts {
|
umode_t mode;
|
};
|
|
static int bpf_parse_param(struct fs_context *fc, struct fs_parameter *param)
|
{
|
struct bpf_mount_opts *opts = fc->fs_private;
|
struct fs_parse_result result;
|
int opt;
|
|
opt = fs_parse(fc, bpf_fs_parameters, param, &result);
|
if (opt < 0)
|
/* We might like to report bad mount options here, but
|
* traditionally we've ignored all mount options, so we'd
|
* better continue to ignore non-existing options for bpf.
|
*/
|
return opt == -ENOPARAM ? 0 : opt;
|
|
switch (opt) {
|
case OPT_MODE:
|
opts->mode = result.uint_32 & S_IALLUGO;
|
break;
|
}
|
|
return 0;
|
}
|
|
struct bpf_preload_ops *bpf_preload_ops;
|
EXPORT_SYMBOL_GPL(bpf_preload_ops);
|
|
static bool bpf_preload_mod_get(void)
|
{
|
/* If bpf_preload.ko wasn't loaded earlier then load it now.
|
* When bpf_preload is built into vmlinux the module's __init
|
* function will populate it.
|
*/
|
if (!bpf_preload_ops) {
|
request_module("bpf_preload");
|
if (!bpf_preload_ops)
|
return false;
|
}
|
/* And grab the reference, so the module doesn't disappear while the
|
* kernel is interacting with the kernel module and its UMD.
|
*/
|
if (!try_module_get(bpf_preload_ops->owner)) {
|
pr_err("bpf_preload module get failed.\n");
|
return false;
|
}
|
return true;
|
}
|
|
static void bpf_preload_mod_put(void)
|
{
|
if (bpf_preload_ops)
|
/* now user can "rmmod bpf_preload" if necessary */
|
module_put(bpf_preload_ops->owner);
|
}
|
|
static DEFINE_MUTEX(bpf_preload_lock);
|
|
static int populate_bpffs(struct dentry *parent)
|
{
|
struct bpf_preload_info objs[BPF_PRELOAD_LINKS] = {};
|
struct bpf_link *links[BPF_PRELOAD_LINKS] = {};
|
int err = 0, i;
|
|
/* grab the mutex to make sure the kernel interactions with bpf_preload
|
* UMD are serialized
|
*/
|
mutex_lock(&bpf_preload_lock);
|
|
/* if bpf_preload.ko wasn't built into vmlinux then load it */
|
if (!bpf_preload_mod_get())
|
goto out;
|
|
if (!bpf_preload_ops->info.tgid) {
|
/* preload() will start UMD that will load BPF iterator programs */
|
err = bpf_preload_ops->preload(objs);
|
if (err)
|
goto out_put;
|
for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
|
links[i] = bpf_link_by_id(objs[i].link_id);
|
if (IS_ERR(links[i])) {
|
err = PTR_ERR(links[i]);
|
goto out_put;
|
}
|
}
|
for (i = 0; i < BPF_PRELOAD_LINKS; i++) {
|
err = bpf_iter_link_pin_kernel(parent,
|
objs[i].link_name, links[i]);
|
if (err)
|
goto out_put;
|
/* do not unlink successfully pinned links even
|
* if later link fails to pin
|
*/
|
links[i] = NULL;
|
}
|
/* finish() will tell UMD process to exit */
|
err = bpf_preload_ops->finish();
|
if (err)
|
goto out_put;
|
}
|
out_put:
|
bpf_preload_mod_put();
|
out:
|
mutex_unlock(&bpf_preload_lock);
|
for (i = 0; i < BPF_PRELOAD_LINKS && err; i++)
|
if (!IS_ERR_OR_NULL(links[i]))
|
bpf_link_put(links[i]);
|
return err;
|
}
|
|
static int bpf_fill_super(struct super_block *sb, struct fs_context *fc)
|
{
|
static const struct tree_descr bpf_rfiles[] = { { "" } };
|
struct bpf_mount_opts *opts = fc->fs_private;
|
struct inode *inode;
|
int ret;
|
|
ret = simple_fill_super(sb, BPF_FS_MAGIC, bpf_rfiles);
|
if (ret)
|
return ret;
|
|
sb->s_op = &bpf_super_ops;
|
|
inode = sb->s_root->d_inode;
|
inode->i_op = &bpf_dir_iops;
|
inode->i_mode &= ~S_IALLUGO;
|
populate_bpffs(sb->s_root);
|
inode->i_mode |= S_ISVTX | opts->mode;
|
return 0;
|
}
|
|
static int bpf_get_tree(struct fs_context *fc)
|
{
|
return get_tree_nodev(fc, bpf_fill_super);
|
}
|
|
static void bpf_free_fc(struct fs_context *fc)
|
{
|
kfree(fc->fs_private);
|
}
|
|
static const struct fs_context_operations bpf_context_ops = {
|
.free = bpf_free_fc,
|
.parse_param = bpf_parse_param,
|
.get_tree = bpf_get_tree,
|
};
|
|
/*
|
* Set up the filesystem mount context.
|
*/
|
static int bpf_init_fs_context(struct fs_context *fc)
|
{
|
struct bpf_mount_opts *opts;
|
|
opts = kzalloc(sizeof(struct bpf_mount_opts), GFP_KERNEL);
|
if (!opts)
|
return -ENOMEM;
|
|
opts->mode = S_IRWXUGO;
|
|
fc->fs_private = opts;
|
fc->ops = &bpf_context_ops;
|
return 0;
|
}
|
|
static struct file_system_type bpf_fs_type = {
|
.owner = THIS_MODULE,
|
.name = "bpf",
|
.init_fs_context = bpf_init_fs_context,
|
.parameters = bpf_fs_parameters,
|
.kill_sb = kill_litter_super,
|
};
|
|
static int __init bpf_init(void)
|
{
|
int ret;
|
|
mutex_init(&bpf_preload_lock);
|
|
ret = sysfs_create_mount_point(fs_kobj, "bpf");
|
if (ret)
|
return ret;
|
|
ret = register_filesystem(&bpf_fs_type);
|
if (ret)
|
sysfs_remove_mount_point(fs_kobj, "bpf");
|
|
return ret;
|
}
|
fs_initcall(bpf_init);
|
