mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
831 lines
17 KiB
831 lines
17 KiB
// 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 <[email protected]> |
|
*/ |
|
|
|
#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(&init_user_ns, 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 user_namespace *mnt_userns, 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 user_namespace *mnt_userns, 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 = path_permission(&path, 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 = (f_flags != O_RDWR) ? -EINVAL : 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(&init_user_ns, 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);
|
|
|