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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/kernel/bpf/syscall.c

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48 KiB
C
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/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* 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.
*/
#include <linux/bpf.h>
#include <linux/bpf_trace.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>
#include <linux/vmalloc.h>
#include <linux/mmzone.h>
#include <linux/anon_inodes.h>
#include <linux/file.h>
#include <linux/license.h>
#include <linux/filter.h>
#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/idr.h>
#include <linux/cred.h>
#include <linux/timekeeping.h>
#include <linux/ctype.h>
#include <linux/nospec.h>
#define IS_FD_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY || \
(map)->map_type == BPF_MAP_TYPE_PERF_EVENT_ARRAY || \
(map)->map_type == BPF_MAP_TYPE_CGROUP_ARRAY || \
(map)->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
#define IS_FD_HASH(map) ((map)->map_type == BPF_MAP_TYPE_HASH_OF_MAPS)
#define IS_FD_MAP(map) (IS_FD_ARRAY(map) || IS_FD_HASH(map))
#define BPF_OBJ_FLAG_MASK (BPF_F_RDONLY | BPF_F_WRONLY)
DEFINE_PER_CPU(int, bpf_prog_active);
static DEFINE_IDR(prog_idr);
static DEFINE_SPINLOCK(prog_idr_lock);
static DEFINE_IDR(map_idr);
static DEFINE_SPINLOCK(map_idr_lock);
int sysctl_unprivileged_bpf_disabled __read_mostly;
static const struct bpf_map_ops * const bpf_map_types[] = {
#define BPF_PROG_TYPE(_id, _ops)
#define BPF_MAP_TYPE(_id, _ops) \
[_id] = &_ops,
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
};
/*
* If we're handed a bigger struct than we know of, ensure all the unknown bits
* are 0 - i.e. new user-space does not rely on any kernel feature extensions
* we don't know about yet.
*
* There is a ToCToU between this function call and the following
* copy_from_user() call. However, this is not a concern since this function is
* meant to be a future-proofing of bits.
*/
static int check_uarg_tail_zero(void __user *uaddr,
size_t expected_size,
size_t actual_size)
{
unsigned char __user *addr;
unsigned char __user *end;
unsigned char val;
int err;
if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
return -E2BIG;
if (unlikely(!access_ok(VERIFY_READ, uaddr, actual_size)))
return -EFAULT;
if (actual_size <= expected_size)
return 0;
addr = uaddr + expected_size;
end = uaddr + actual_size;
for (; addr < end; addr++) {
err = get_user(val, addr);
if (err)
return err;
if (val)
return -E2BIG;
}
return 0;
}
const struct bpf_map_ops bpf_map_offload_ops = {
.map_alloc = bpf_map_offload_map_alloc,
.map_free = bpf_map_offload_map_free,
};
static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
{
const struct bpf_map_ops *ops;
u32 type = attr->map_type;
struct bpf_map *map;
int err;
if (type >= ARRAY_SIZE(bpf_map_types))
return ERR_PTR(-EINVAL);
type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
ops = bpf_map_types[type];
if (!ops)
return ERR_PTR(-EINVAL);
if (ops->map_alloc_check) {
err = ops->map_alloc_check(attr);
if (err)
return ERR_PTR(err);
}
if (attr->map_ifindex)
ops = &bpf_map_offload_ops;
map = ops->map_alloc(attr);
if (IS_ERR(map))
return map;
map->ops = ops;
map->map_type = type;
return map;
}
void *bpf_map_area_alloc(size_t size, int numa_node)
{
/* We definitely need __GFP_NORETRY, so OOM killer doesn't
* trigger under memory pressure as we really just want to
* fail instead.
*/
const gfp_t flags = __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO;
void *area;
if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
area = kmalloc_node(size, GFP_USER | flags, numa_node);
if (area != NULL)
return area;
}
return __vmalloc_node_flags_caller(size, numa_node, GFP_KERNEL | flags,
__builtin_return_address(0));
}
void bpf_map_area_free(void *area)
{
kvfree(area);
}
void bpf_map_init_from_attr(struct bpf_map *map, union bpf_attr *attr)
{
map->map_type = attr->map_type;
map->key_size = attr->key_size;
map->value_size = attr->value_size;
map->max_entries = attr->max_entries;
map->map_flags = attr->map_flags;
map->numa_node = bpf_map_attr_numa_node(attr);
}
int bpf_map_precharge_memlock(u32 pages)
{
struct user_struct *user = get_current_user();
unsigned long memlock_limit, cur;
memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
cur = atomic_long_read(&user->locked_vm);
free_uid(user);
if (cur + pages > memlock_limit)
return -EPERM;
return 0;
}
static int bpf_map_charge_memlock(struct bpf_map *map)
{
struct user_struct *user = get_current_user();
unsigned long memlock_limit;
memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
atomic_long_add(map->pages, &user->locked_vm);
if (atomic_long_read(&user->locked_vm) > memlock_limit) {
atomic_long_sub(map->pages, &user->locked_vm);
free_uid(user);
return -EPERM;
}
map->user = user;
return 0;
}
static void bpf_map_uncharge_memlock(struct bpf_map *map)
{
struct user_struct *user = map->user;
atomic_long_sub(map->pages, &user->locked_vm);
free_uid(user);
}
static int bpf_map_alloc_id(struct bpf_map *map)
{
int id;
idr_preload(GFP_KERNEL);
spin_lock_bh(&map_idr_lock);
id = idr_alloc_cyclic(&map_idr, map, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
map->id = id;
spin_unlock_bh(&map_idr_lock);
idr_preload_end();
if (WARN_ON_ONCE(!id))
return -ENOSPC;
return id > 0 ? 0 : id;
}
void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock)
{
unsigned long flags;
/* Offloaded maps are removed from the IDR store when their device
* disappears - even if someone holds an fd to them they are unusable,
* the memory is gone, all ops will fail; they are simply waiting for
* refcnt to drop to be freed.
*/
if (!map->id)
return;
if (do_idr_lock)
spin_lock_irqsave(&map_idr_lock, flags);
else
__acquire(&map_idr_lock);
idr_remove(&map_idr, map->id);
map->id = 0;
if (do_idr_lock)
spin_unlock_irqrestore(&map_idr_lock, flags);
else
__release(&map_idr_lock);
}
/* called from workqueue */
static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
bpf_map_uncharge_memlock(map);
security_bpf_map_free(map);
/* implementation dependent freeing */
map->ops->map_free(map);
}
static void bpf_map_put_uref(struct bpf_map *map)
{
if (atomic_dec_and_test(&map->usercnt)) {
if (map->ops->map_release_uref)
map->ops->map_release_uref(map);
}
}
/* decrement map refcnt and schedule it for freeing via workqueue
* (unrelying map implementation ops->map_free() might sleep)
*/
static void __bpf_map_put(struct bpf_map *map, bool do_idr_lock)
{
if (atomic_dec_and_test(&map->refcnt)) {
/* bpf_map_free_id() must be called first */
bpf_map_free_id(map, do_idr_lock);
INIT_WORK(&map->work, bpf_map_free_deferred);
schedule_work(&map->work);
}
}
void bpf_map_put(struct bpf_map *map)
{
__bpf_map_put(map, true);
}
void bpf_map_put_with_uref(struct bpf_map *map)
{
bpf_map_put_uref(map);
bpf_map_put(map);
}
static int bpf_map_release(struct inode *inode, struct file *filp)
{
struct bpf_map *map = filp->private_data;
if (map->ops->map_release)
map->ops->map_release(map, filp);
bpf_map_put_with_uref(map);
return 0;
}
#ifdef CONFIG_PROC_FS
static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
{
const struct bpf_map *map = filp->private_data;
const struct bpf_array *array;
u32 owner_prog_type = 0;
u32 owner_jited = 0;
if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) {
array = container_of(map, struct bpf_array, map);
owner_prog_type = array->owner_prog_type;
owner_jited = array->owner_jited;
}
seq_printf(m,
"map_type:\t%u\n"
"key_size:\t%u\n"
"value_size:\t%u\n"
"max_entries:\t%u\n"
"map_flags:\t%#x\n"
"memlock:\t%llu\n",
map->map_type,
map->key_size,
map->value_size,
map->max_entries,
map->map_flags,
map->pages * 1ULL << PAGE_SHIFT);
if (owner_prog_type) {
seq_printf(m, "owner_prog_type:\t%u\n",
owner_prog_type);
seq_printf(m, "owner_jited:\t%u\n",
owner_jited);
}
}
#endif
static ssize_t bpf_dummy_read(struct file *filp, char __user *buf, size_t siz,
loff_t *ppos)
{
/* We need this handler such that alloc_file() enables
* f_mode with FMODE_CAN_READ.
*/
return -EINVAL;
}
static ssize_t bpf_dummy_write(struct file *filp, const char __user *buf,
size_t siz, loff_t *ppos)
{
/* We need this handler such that alloc_file() enables
* f_mode with FMODE_CAN_WRITE.
*/
return -EINVAL;
}
const struct file_operations bpf_map_fops = {
#ifdef CONFIG_PROC_FS
.show_fdinfo = bpf_map_show_fdinfo,
#endif
.release = bpf_map_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
};
int bpf_map_new_fd(struct bpf_map *map, int flags)
{
int ret;
ret = security_bpf_map(map, OPEN_FMODE(flags));
if (ret < 0)
return ret;
return anon_inode_getfd("bpf-map", &bpf_map_fops, map,
flags | O_CLOEXEC);
}
int bpf_get_file_flag(int flags)
{
if ((flags & BPF_F_RDONLY) && (flags & BPF_F_WRONLY))
return -EINVAL;
if (flags & BPF_F_RDONLY)
return O_RDONLY;
if (flags & BPF_F_WRONLY)
return O_WRONLY;
return O_RDWR;
}
/* helper macro to check that unused fields 'union bpf_attr' are zero */
#define CHECK_ATTR(CMD) \
memchr_inv((void *) &attr->CMD##_LAST_FIELD + \
sizeof(attr->CMD##_LAST_FIELD), 0, \
sizeof(*attr) - \
offsetof(union bpf_attr, CMD##_LAST_FIELD) - \
sizeof(attr->CMD##_LAST_FIELD)) != NULL
/* dst and src must have at least BPF_OBJ_NAME_LEN number of bytes.
* Return 0 on success and < 0 on error.
*/
static int bpf_obj_name_cpy(char *dst, const char *src)
{
const char *end = src + BPF_OBJ_NAME_LEN;
memset(dst, 0, BPF_OBJ_NAME_LEN);
/* Copy all isalnum() and '_' char */
while (src < end && *src) {
if (!isalnum(*src) && *src != '_')
return -EINVAL;
*dst++ = *src++;
}
/* No '\0' found in BPF_OBJ_NAME_LEN number of bytes */
if (src == end)
return -EINVAL;
return 0;
}
#define BPF_MAP_CREATE_LAST_FIELD map_ifindex
/* called via syscall */
static int map_create(union bpf_attr *attr)
{
int numa_node = bpf_map_attr_numa_node(attr);
struct bpf_map *map;
int f_flags;
int err;
err = CHECK_ATTR(BPF_MAP_CREATE);
if (err)
return -EINVAL;
f_flags = bpf_get_file_flag(attr->map_flags);
if (f_flags < 0)
return f_flags;
if (numa_node != NUMA_NO_NODE &&
((unsigned int)numa_node >= nr_node_ids ||
!node_online(numa_node)))
return -EINVAL;
/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
map = find_and_alloc_map(attr);
if (IS_ERR(map))
return PTR_ERR(map);
err = bpf_obj_name_cpy(map->name, attr->map_name);
if (err)
goto free_map_nouncharge;
atomic_set(&map->refcnt, 1);
atomic_set(&map->usercnt, 1);
err = security_bpf_map_alloc(map);
if (err)
goto free_map_nouncharge;
err = bpf_map_charge_memlock(map);
if (err)
goto free_map_sec;
err = bpf_map_alloc_id(map);
if (err)
goto free_map;
err = bpf_map_new_fd(map, f_flags);
if (err < 0) {
/* failed to allocate fd.
* bpf_map_put() is needed because the above
* bpf_map_alloc_id() has published the map
* to the userspace and the userspace may
* have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
*/
bpf_map_put(map);
return err;
}
trace_bpf_map_create(map, err);
return err;
free_map:
bpf_map_uncharge_memlock(map);
free_map_sec:
security_bpf_map_free(map);
free_map_nouncharge:
map->ops->map_free(map);
return err;
}
/* if error is returned, fd is released.
* On success caller should complete fd access with matching fdput()
*/
struct bpf_map *__bpf_map_get(struct fd f)
{
if (!f.file)
return ERR_PTR(-EBADF);
if (f.file->f_op != &bpf_map_fops) {
fdput(f);
return ERR_PTR(-EINVAL);
}
return f.file->private_data;
}
/* prog's and map's refcnt limit */
#define BPF_MAX_REFCNT 32768
struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
{
if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
atomic_dec(&map->refcnt);
return ERR_PTR(-EBUSY);
}
if (uref)
atomic_inc(&map->usercnt);
return map;
}
struct bpf_map *bpf_map_get_with_uref(u32 ufd)
{
struct fd f = fdget(ufd);
struct bpf_map *map;
map = __bpf_map_get(f);
if (IS_ERR(map))
return map;
map = bpf_map_inc(map, true);
fdput(f);
return map;
}
/* map_idr_lock should have been held */
static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
bool uref)
{
int refold;
refold = __atomic_add_unless(&map->refcnt, 1, 0);
if (refold >= BPF_MAX_REFCNT) {
__bpf_map_put(map, false);
return ERR_PTR(-EBUSY);
}
if (!refold)
return ERR_PTR(-ENOENT);
if (uref)
atomic_inc(&map->usercnt);
return map;
}
int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
{
return -ENOTSUPP;
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD value
static int map_lookup_elem(union bpf_attr *attr)
{
void __user *ukey = u64_to_user_ptr(attr->key);
void __user *uvalue = u64_to_user_ptr(attr->value);
int ufd = attr->map_fd;
struct bpf_map *map;
void *key, *value, *ptr;
u32 value_size;
struct fd f;
int err;
if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(f.file->f_mode & FMODE_CAN_READ)) {
err = -EPERM;
goto err_put;
}
key = memdup_user(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
value_size = round_up(map->value_size, 8) * num_possible_cpus();
else if (IS_FD_MAP(map))
value_size = sizeof(u32);
else
value_size = map->value_size;
err = -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
if (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_lookup_elem(map, key, value);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
err = bpf_percpu_hash_copy(map, key, value);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
err = bpf_percpu_array_copy(map, key, value);
} else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) {
err = bpf_stackmap_copy(map, key, value);
} else if (IS_FD_ARRAY(map)) {
err = bpf_fd_array_map_lookup_elem(map, key, value);
} else if (IS_FD_HASH(map)) {
err = bpf_fd_htab_map_lookup_elem(map, key, value);
} else {
rcu_read_lock();
ptr = map->ops->map_lookup_elem(map, key);
if (ptr)
memcpy(value, ptr, value_size);
rcu_read_unlock();
err = ptr ? 0 : -ENOENT;
}
if (err)
goto free_value;
err = -EFAULT;
if (copy_to_user(uvalue, value, value_size) != 0)
goto free_value;
trace_bpf_map_lookup_elem(map, ufd, key, value);
err = 0;
free_value:
kfree(value);
free_key:
kfree(key);
err_put:
fdput(f);
return err;
}
#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
static int map_update_elem(union bpf_attr *attr)
{
void __user *ukey = u64_to_user_ptr(attr->key);
void __user *uvalue = u64_to_user_ptr(attr->value);
int ufd = attr->map_fd;
struct bpf_map *map;
void *key, *value;
u32 value_size;
struct fd f;
int err;
if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
key = memdup_user(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY)
value_size = round_up(map->value_size, 8) * num_possible_cpus();
else
value_size = map->value_size;
err = -ENOMEM;
value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
err = -EFAULT;
if (copy_from_user(value, uvalue, value_size) != 0)
goto free_value;
/* Need to create a kthread, thus must support schedule */
if (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_update_elem(map, key, value, attr->flags);
goto out;
} else if (map->map_type == BPF_MAP_TYPE_CPUMAP) {
err = map->ops->map_update_elem(map, key, value, attr->flags);
goto out;
}
/* must increment bpf_prog_active to avoid kprobe+bpf triggering from
* inside bpf map update or delete otherwise deadlocks are possible
*/
preempt_disable();
__this_cpu_inc(bpf_prog_active);
if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
err = bpf_percpu_hash_update(map, key, value, attr->flags);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
err = bpf_percpu_array_update(map, key, value, attr->flags);
} else if (IS_FD_ARRAY(map)) {
rcu_read_lock();
err = bpf_fd_array_map_update_elem(map, f.file, key, value,
attr->flags);
rcu_read_unlock();
} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
rcu_read_lock();
err = bpf_fd_htab_map_update_elem(map, f.file, key, value,
attr->flags);
rcu_read_unlock();
} else {
rcu_read_lock();
err = map->ops->map_update_elem(map, key, value, attr->flags);
rcu_read_unlock();
}
__this_cpu_dec(bpf_prog_active);
preempt_enable();
out:
if (!err)
trace_bpf_map_update_elem(map, ufd, key, value);
free_value:
kfree(value);
free_key:
kfree(key);
err_put:
fdput(f);
return err;
}
#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
static int map_delete_elem(union bpf_attr *attr)
{
void __user *ukey = u64_to_user_ptr(attr->key);
int ufd = attr->map_fd;
struct bpf_map *map;
struct fd f;
void *key;
int err;
if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(f.file->f_mode & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
key = memdup_user(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
if (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_delete_elem(map, key);
goto out;
}
preempt_disable();
__this_cpu_inc(bpf_prog_active);
rcu_read_lock();
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
__this_cpu_dec(bpf_prog_active);
preempt_enable();
out:
if (!err)
trace_bpf_map_delete_elem(map, ufd, key);
kfree(key);
err_put:
fdput(f);
return err;
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_GET_NEXT_KEY_LAST_FIELD next_key
static int map_get_next_key(union bpf_attr *attr)
{
void __user *ukey = u64_to_user_ptr(attr->key);
void __user *unext_key = u64_to_user_ptr(attr->next_key);
int ufd = attr->map_fd;
struct bpf_map *map;
void *key, *next_key;
struct fd f;
int err;
if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
return -EINVAL;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(f.file->f_mode & FMODE_CAN_READ)) {
err = -EPERM;
goto err_put;
}
if (ukey) {
key = memdup_user(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
} else {
key = NULL;
}
err = -ENOMEM;
next_key = kmalloc(map->key_size, GFP_USER);
if (!next_key)
goto free_key;
if (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_get_next_key(map, key, next_key);
goto out;
}
rcu_read_lock();
err = map->ops->map_get_next_key(map, key, next_key);
rcu_read_unlock();
out:
if (err)
goto free_next_key;
err = -EFAULT;
if (copy_to_user(unext_key, next_key, map->key_size) != 0)
goto free_next_key;
trace_bpf_map_next_key(map, ufd, key, next_key);
err = 0;
free_next_key:
kfree(next_key);
free_key:
kfree(key);
err_put:
fdput(f);
return err;
}
static const struct bpf_prog_ops * const bpf_prog_types[] = {
#define BPF_PROG_TYPE(_id, _name) \
[_id] = & _name ## _prog_ops,
#define BPF_MAP_TYPE(_id, _ops)
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
};
static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog)
{
const struct bpf_prog_ops *ops;
if (type >= ARRAY_SIZE(bpf_prog_types))
return -EINVAL;
type = array_index_nospec(type, ARRAY_SIZE(bpf_prog_types));
ops = bpf_prog_types[type];
if (!ops)
return -EINVAL;
if (!bpf_prog_is_dev_bound(prog->aux))
prog->aux->ops = ops;
else
prog->aux->ops = &bpf_offload_prog_ops;
prog->type = type;
return 0;
}
/* drop refcnt on maps used by eBPF program and free auxilary data */
static void free_used_maps(struct bpf_prog_aux *aux)
{
int i;
for (i = 0; i < aux->used_map_cnt; i++)
bpf_map_put(aux->used_maps[i]);
kfree(aux->used_maps);
}
int __bpf_prog_charge(struct user_struct *user, u32 pages)
{
unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
unsigned long user_bufs;
if (user) {
user_bufs = atomic_long_add_return(pages, &user->locked_vm);
if (user_bufs > memlock_limit) {
atomic_long_sub(pages, &user->locked_vm);
return -EPERM;
}
}
return 0;
}
void __bpf_prog_uncharge(struct user_struct *user, u32 pages)
{
if (user)
atomic_long_sub(pages, &user->locked_vm);
}
static int bpf_prog_charge_memlock(struct bpf_prog *prog)
{
struct user_struct *user = get_current_user();
int ret;
ret = __bpf_prog_charge(user, prog->pages);
if (ret) {
free_uid(user);
return ret;
}
prog->aux->user = user;
return 0;
}
static void bpf_prog_uncharge_memlock(struct bpf_prog *prog)
{
struct user_struct *user = prog->aux->user;
__bpf_prog_uncharge(user, prog->pages);
free_uid(user);
}
static int bpf_prog_alloc_id(struct bpf_prog *prog)
{
int id;
idr_preload(GFP_KERNEL);
spin_lock_bh(&prog_idr_lock);
id = idr_alloc_cyclic(&prog_idr, prog, 1, INT_MAX, GFP_ATOMIC);
if (id > 0)
prog->aux->id = id;
spin_unlock_bh(&prog_idr_lock);
idr_preload_end();
/* id is in [1, INT_MAX) */
if (WARN_ON_ONCE(!id))
return -ENOSPC;
return id > 0 ? 0 : id;
}
void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
{
/* cBPF to eBPF migrations are currently not in the idr store.
* Offloaded programs are removed from the store when their device
* disappears - even if someone grabs an fd to them they are unusable,
* simply waiting for refcnt to drop to be freed.
*/
if (!prog->aux->id)
return;
if (do_idr_lock)
spin_lock_bh(&prog_idr_lock);
else
__acquire(&prog_idr_lock);
idr_remove(&prog_idr, prog->aux->id);
prog->aux->id = 0;
if (do_idr_lock)
spin_unlock_bh(&prog_idr_lock);
else
__release(&prog_idr_lock);
}
static void __bpf_prog_put_rcu(struct rcu_head *rcu)
{
struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
free_used_maps(aux);
bpf_prog_uncharge_memlock(aux->prog);
security_bpf_prog_free(aux);
bpf_prog_free(aux->prog);
}
static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
{
if (atomic_dec_and_test(&prog->aux->refcnt)) {
int i;
trace_bpf_prog_put_rcu(prog);
/* bpf_prog_free_id() must be called first */
bpf_prog_free_id(prog, do_idr_lock);
for (i = 0; i < prog->aux->func_cnt; i++)
bpf_prog_kallsyms_del(prog->aux->func[i]);
bpf_prog_kallsyms_del(prog);
call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
}
}
void bpf_prog_put(struct bpf_prog *prog)
{
__bpf_prog_put(prog, true);
}
EXPORT_SYMBOL_GPL(bpf_prog_put);
static int bpf_prog_release(struct inode *inode, struct file *filp)
{
struct bpf_prog *prog = filp->private_data;
bpf_prog_put(prog);
return 0;
}
#ifdef CONFIG_PROC_FS
static void bpf_prog_show_fdinfo(struct seq_file *m, struct file *filp)
{
const struct bpf_prog *prog = filp->private_data;
char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
seq_printf(m,
"prog_type:\t%u\n"
"prog_jited:\t%u\n"
"prog_tag:\t%s\n"
"memlock:\t%llu\n",
prog->type,
prog->jited,
prog_tag,
prog->pages * 1ULL << PAGE_SHIFT);
}
#endif
const struct file_operations bpf_prog_fops = {
#ifdef CONFIG_PROC_FS
.show_fdinfo = bpf_prog_show_fdinfo,
#endif
.release = bpf_prog_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
};
int bpf_prog_new_fd(struct bpf_prog *prog)
{
int ret;
ret = security_bpf_prog(prog);
if (ret < 0)
return ret;
return anon_inode_getfd("bpf-prog", &bpf_prog_fops, prog,
O_RDWR | O_CLOEXEC);
}
static struct bpf_prog *____bpf_prog_get(struct fd f)
{
if (!f.file)
return ERR_PTR(-EBADF);
if (f.file->f_op != &bpf_prog_fops) {
fdput(f);
return ERR_PTR(-EINVAL);
}
return f.file->private_data;
}
struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
{
if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
atomic_sub(i, &prog->aux->refcnt);
return ERR_PTR(-EBUSY);
}
return prog;
}
EXPORT_SYMBOL_GPL(bpf_prog_add);
void bpf_prog_sub(struct bpf_prog *prog, int i)
{
/* Only to be used for undoing previous bpf_prog_add() in some
* error path. We still know that another entity in our call
* path holds a reference to the program, thus atomic_sub() can
* be safely used in such cases!
*/
WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
}
EXPORT_SYMBOL_GPL(bpf_prog_sub);
struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
{
return bpf_prog_add(prog, 1);
}
EXPORT_SYMBOL_GPL(bpf_prog_inc);
/* prog_idr_lock should have been held */
struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
{
int refold;
refold = __atomic_add_unless(&prog->aux->refcnt, 1, 0);
if (refold >= BPF_MAX_REFCNT) {
__bpf_prog_put(prog, false);
return ERR_PTR(-EBUSY);
}
if (!refold)
return ERR_PTR(-ENOENT);
return prog;
}
EXPORT_SYMBOL_GPL(bpf_prog_inc_not_zero);
bool bpf_prog_get_ok(struct bpf_prog *prog,
enum bpf_prog_type *attach_type, bool attach_drv)
{
/* not an attachment, just a refcount inc, always allow */
if (!attach_type)
return true;
if (prog->type != *attach_type)
return false;
if (bpf_prog_is_dev_bound(prog->aux) && !attach_drv)
return false;
return true;
}
static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
bool attach_drv)
{
struct fd f = fdget(ufd);
struct bpf_prog *prog;
prog = ____bpf_prog_get(f);
if (IS_ERR(prog))
return prog;
if (!bpf_prog_get_ok(prog, attach_type, attach_drv)) {
prog = ERR_PTR(-EINVAL);
goto out;
}
prog = bpf_prog_inc(prog);
out:
fdput(f);
return prog;
}
struct bpf_prog *bpf_prog_get(u32 ufd)
{
return __bpf_prog_get(ufd, NULL, false);
}
struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
bool attach_drv)
{
struct bpf_prog *prog = __bpf_prog_get(ufd, &type, attach_drv);
if (!IS_ERR(prog))
trace_bpf_prog_get_type(prog);
return prog;
}
EXPORT_SYMBOL_GPL(bpf_prog_get_type_dev);
/* Initially all BPF programs could be loaded w/o specifying
* expected_attach_type. Later for some of them specifying expected_attach_type
* at load time became required so that program could be validated properly.
* Programs of types that are allowed to be loaded both w/ and w/o (for
* backward compatibility) expected_attach_type, should have the default attach
* type assigned to expected_attach_type for the latter case, so that it can be
* validated later at attach time.
*
* bpf_prog_load_fixup_attach_type() sets expected_attach_type in @attr if
* prog type requires it but has some attach types that have to be backward
* compatible.
*/
static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr)
{
switch (attr->prog_type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
/* Unfortunately BPF_ATTACH_TYPE_UNSPEC enumeration doesn't
* exist so checking for non-zero is the way to go here.
*/
if (!attr->expected_attach_type)
attr->expected_attach_type =
BPF_CGROUP_INET_SOCK_CREATE;
break;
}
}
static int
bpf_prog_load_check_attach_type(enum bpf_prog_type prog_type,
enum bpf_attach_type expected_attach_type)
{
switch (prog_type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
switch (expected_attach_type) {
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
return 0;
default:
return -EINVAL;
}
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
switch (expected_attach_type) {
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
return 0;
default:
return -EINVAL;
}
default:
return 0;
}
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD expected_attach_type
static int bpf_prog_load(union bpf_attr *attr)
{
enum bpf_prog_type type = attr->prog_type;
struct bpf_prog *prog;
int err;
char license[128];
bool is_gpl;
if (CHECK_ATTR(BPF_PROG_LOAD))
return -EINVAL;
if (attr->prog_flags & ~BPF_F_STRICT_ALIGNMENT)
return -EINVAL;
/* copy eBPF program license from user space */
if (strncpy_from_user(license, u64_to_user_ptr(attr->license),
sizeof(license) - 1) < 0)
return -EFAULT;
license[sizeof(license) - 1] = 0;
/* eBPF programs must be GPL compatible to use GPL-ed functions */
is_gpl = license_is_gpl_compatible(license);
if (attr->insn_cnt == 0 || attr->insn_cnt > BPF_MAXINSNS)
return -E2BIG;
if (type == BPF_PROG_TYPE_KPROBE &&
attr->kern_version != LINUX_VERSION_CODE)
return -EINVAL;
if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
type != BPF_PROG_TYPE_CGROUP_SKB &&
!capable(CAP_SYS_ADMIN))
return -EPERM;
bpf_prog_load_fixup_attach_type(attr);
if (bpf_prog_load_check_attach_type(type, attr->expected_attach_type))
return -EINVAL;
/* plain bpf_prog allocation */
prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
if (!prog)
return -ENOMEM;
prog->expected_attach_type = attr->expected_attach_type;
prog->aux->offload_requested = !!attr->prog_ifindex;
err = security_bpf_prog_alloc(prog->aux);
if (err)
goto free_prog_nouncharge;
err = bpf_prog_charge_memlock(prog);
if (err)
goto free_prog_sec;
prog->len = attr->insn_cnt;
err = -EFAULT;
if (copy_from_user(prog->insns, u64_to_user_ptr(attr->insns),
bpf_prog_insn_size(prog)) != 0)
goto free_prog;
prog->orig_prog = NULL;
prog->jited = 0;
atomic_set(&prog->aux->refcnt, 1);
prog->gpl_compatible = is_gpl ? 1 : 0;
if (bpf_prog_is_dev_bound(prog->aux)) {
err = bpf_prog_offload_init(prog, attr);
if (err)
goto free_prog;
}
/* find program type: socket_filter vs tracing_filter */
err = find_prog_type(type, prog);
if (err < 0)
goto free_prog;
prog->aux->load_time = ktime_get_boot_ns();
err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name);
if (err)
goto free_prog;
/* run eBPF verifier */
err = bpf_check(&prog, attr);
if (err < 0)
goto free_used_maps;
/* eBPF program is ready to be JITed */
if (!prog->bpf_func)
prog = bpf_prog_select_runtime(prog, &err);
if (err < 0)
goto free_used_maps;
err = bpf_prog_alloc_id(prog);
if (err)
goto free_used_maps;
err = bpf_prog_new_fd(prog);
if (err < 0) {
/* failed to allocate fd.
* bpf_prog_put() is needed because the above
* bpf_prog_alloc_id() has published the prog
* to the userspace and the userspace may
* have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
*/
bpf_prog_put(prog);
return err;
}
bpf_prog_kallsyms_add(prog);
trace_bpf_prog_load(prog, err);
return err;
free_used_maps:
free_used_maps(prog->aux);
free_prog:
bpf_prog_uncharge_memlock(prog);
free_prog_sec:
security_bpf_prog_free(prog->aux);
free_prog_nouncharge:
bpf_prog_free(prog);
return err;
}
#define BPF_OBJ_LAST_FIELD file_flags
static int bpf_obj_pin(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
return -EINVAL;
return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
}
static int bpf_obj_get(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
attr->file_flags & ~BPF_OBJ_FLAG_MASK)
return -EINVAL;
return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
attr->file_flags);
}
struct bpf_raw_tracepoint {
struct bpf_raw_event_map *btp;
struct bpf_prog *prog;
};
static int bpf_raw_tracepoint_release(struct inode *inode, struct file *filp)
{
struct bpf_raw_tracepoint *raw_tp = filp->private_data;
if (raw_tp->prog) {
bpf_probe_unregister(raw_tp->btp, raw_tp->prog);
bpf_prog_put(raw_tp->prog);
}
kfree(raw_tp);
return 0;
}
static const struct file_operations bpf_raw_tp_fops = {
.release = bpf_raw_tracepoint_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
};
#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.prog_fd
static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
struct bpf_raw_tracepoint *raw_tp;
struct bpf_raw_event_map *btp;
struct bpf_prog *prog;
char tp_name[128];
int tp_fd, err;
if (strncpy_from_user(tp_name, u64_to_user_ptr(attr->raw_tracepoint.name),
sizeof(tp_name) - 1) < 0)
return -EFAULT;
tp_name[sizeof(tp_name) - 1] = 0;
btp = bpf_find_raw_tracepoint(tp_name);
if (!btp)
return -ENOENT;
raw_tp = kzalloc(sizeof(*raw_tp), GFP_USER);
if (!raw_tp)
return -ENOMEM;
raw_tp->btp = btp;
prog = bpf_prog_get_type(attr->raw_tracepoint.prog_fd,
BPF_PROG_TYPE_RAW_TRACEPOINT);
if (IS_ERR(prog)) {
err = PTR_ERR(prog);
goto out_free_tp;
}
err = bpf_probe_register(raw_tp->btp, prog);
if (err)
goto out_put_prog;
raw_tp->prog = prog;
tp_fd = anon_inode_getfd("bpf-raw-tracepoint", &bpf_raw_tp_fops, raw_tp,
O_CLOEXEC);
if (tp_fd < 0) {
bpf_probe_unregister(raw_tp->btp, prog);
err = tp_fd;
goto out_put_prog;
}
return tp_fd;
out_put_prog:
bpf_prog_put(prog);
out_free_tp:
kfree(raw_tp);
return err;
}
#ifdef CONFIG_CGROUP_BPF
static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
enum bpf_attach_type attach_type)
{
switch (prog->type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
default:
return 0;
}
}
#define BPF_PROG_ATTACH_LAST_FIELD attach_flags
static int sockmap_get_from_fd(const union bpf_attr *attr,
int type, bool attach)
{
struct bpf_prog *prog = NULL;
int ufd = attr->target_fd;
struct bpf_map *map;
struct fd f;
int err;
f = fdget(ufd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (attach) {
prog = bpf_prog_get_type(attr->attach_bpf_fd, type);
if (IS_ERR(prog)) {
fdput(f);
return PTR_ERR(prog);
}
}
err = sock_map_prog(map, prog, attr->attach_type);
if (err) {
fdput(f);
if (prog)
bpf_prog_put(prog);
return err;
}
fdput(f);
return 0;
}
#define BPF_F_ATTACH_MASK \
(BPF_F_ALLOW_OVERRIDE | BPF_F_ALLOW_MULTI)
static int bpf_prog_attach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
struct cgroup *cgrp;
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;
if (attr->attach_flags & ~BPF_F_ATTACH_MASK)
return -EINVAL;
switch (attr->attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
ptype = BPF_PROG_TYPE_CGROUP_SKB;
break;
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
ptype = BPF_PROG_TYPE_CGROUP_SOCK;
break;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
break;
case BPF_CGROUP_SOCK_OPS:
ptype = BPF_PROG_TYPE_SOCK_OPS;
break;
case BPF_CGROUP_DEVICE:
ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
break;
case BPF_SK_MSG_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, true);
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, true);
default:
return -EINVAL;
}
prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
if (IS_ERR(prog))
return PTR_ERR(prog);
if (bpf_prog_attach_check_attach_type(prog, attr->attach_type)) {
bpf_prog_put(prog);
return -EINVAL;
}
cgrp = cgroup_get_from_fd(attr->target_fd);
if (IS_ERR(cgrp)) {
bpf_prog_put(prog);
return PTR_ERR(cgrp);
}
ret = cgroup_bpf_attach(cgrp, prog, attr->attach_type,
attr->attach_flags);
if (ret)
bpf_prog_put(prog);
cgroup_put(cgrp);
return ret;
}
#define BPF_PROG_DETACH_LAST_FIELD attach_type
static int bpf_prog_detach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
struct cgroup *cgrp;
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_DETACH))
return -EINVAL;
switch (attr->attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
ptype = BPF_PROG_TYPE_CGROUP_SKB;
break;
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
ptype = BPF_PROG_TYPE_CGROUP_SOCK;
break;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
ptype = BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
break;
case BPF_CGROUP_SOCK_OPS:
ptype = BPF_PROG_TYPE_SOCK_OPS;
break;
case BPF_CGROUP_DEVICE:
ptype = BPF_PROG_TYPE_CGROUP_DEVICE;
break;
case BPF_SK_MSG_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_MSG, false);
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
return sockmap_get_from_fd(attr, BPF_PROG_TYPE_SK_SKB, false);
default:
return -EINVAL;
}
cgrp = cgroup_get_from_fd(attr->target_fd);
if (IS_ERR(cgrp))
return PTR_ERR(cgrp);
prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
if (IS_ERR(prog))
prog = NULL;
ret = cgroup_bpf_detach(cgrp, prog, attr->attach_type, 0);
if (prog)
bpf_prog_put(prog);
cgroup_put(cgrp);
return ret;
}
#define BPF_PROG_QUERY_LAST_FIELD query.prog_cnt
static int bpf_prog_query(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct cgroup *cgrp;
int ret;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_QUERY))
return -EINVAL;
if (attr->query.query_flags & ~BPF_F_QUERY_EFFECTIVE)
return -EINVAL;
switch (attr->query.attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
case BPF_CGROUP_SOCK_OPS:
case BPF_CGROUP_DEVICE:
break;
default:
return -EINVAL;
}
cgrp = cgroup_get_from_fd(attr->query.target_fd);
if (IS_ERR(cgrp))
return PTR_ERR(cgrp);
ret = cgroup_bpf_query(cgrp, attr, uattr);
cgroup_put(cgrp);
return ret;
}
#endif /* CONFIG_CGROUP_BPF */
#define BPF_PROG_TEST_RUN_LAST_FIELD test.duration
static int bpf_prog_test_run(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_prog *prog;
int ret = -ENOTSUPP;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (CHECK_ATTR(BPF_PROG_TEST_RUN))
return -EINVAL;
prog = bpf_prog_get(attr->test.prog_fd);
if (IS_ERR(prog))
return PTR_ERR(prog);
if (prog->aux->ops->test_run)
ret = prog->aux->ops->test_run(prog, attr, uattr);
bpf_prog_put(prog);
return ret;
}
#define BPF_OBJ_GET_NEXT_ID_LAST_FIELD next_id
static int bpf_obj_get_next_id(const union bpf_attr *attr,
union bpf_attr __user *uattr,
struct idr *idr,
spinlock_t *lock)
{
u32 next_id = attr->start_id;
int err = 0;
if (CHECK_ATTR(BPF_OBJ_GET_NEXT_ID) || next_id >= INT_MAX)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
next_id++;
spin_lock_bh(lock);
if (!idr_get_next(idr, &next_id))
err = -ENOENT;
spin_unlock_bh(lock);
if (!err)
err = put_user(next_id, &uattr->next_id);
return err;
}
#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
static int bpf_prog_get_fd_by_id(const union bpf_attr *attr)
{
struct bpf_prog *prog;
u32 id = attr->prog_id;
int fd;
if (CHECK_ATTR(BPF_PROG_GET_FD_BY_ID))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
spin_lock_bh(&prog_idr_lock);
prog = idr_find(&prog_idr, id);
if (prog)
prog = bpf_prog_inc_not_zero(prog);
else
prog = ERR_PTR(-ENOENT);
spin_unlock_bh(&prog_idr_lock);
if (IS_ERR(prog))
return PTR_ERR(prog);
fd = bpf_prog_new_fd(prog);
if (fd < 0)
bpf_prog_put(prog);
return fd;
}
#define BPF_MAP_GET_FD_BY_ID_LAST_FIELD open_flags
static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
{
struct bpf_map *map;
u32 id = attr->map_id;
int f_flags;
int fd;
if (CHECK_ATTR(BPF_MAP_GET_FD_BY_ID) ||
attr->open_flags & ~BPF_OBJ_FLAG_MASK)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
f_flags = bpf_get_file_flag(attr->open_flags);
if (f_flags < 0)
return f_flags;
spin_lock_bh(&map_idr_lock);
map = idr_find(&map_idr, id);
if (map)
map = bpf_map_inc_not_zero(map, true);
else
map = ERR_PTR(-ENOENT);
spin_unlock_bh(&map_idr_lock);
if (IS_ERR(map))
return PTR_ERR(map);
fd = bpf_map_new_fd(map, f_flags);
if (fd < 0)
bpf_map_put(map);
return fd;
}
static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
unsigned long addr)
{
int i;
for (i = 0; i < prog->aux->used_map_cnt; i++)
if (prog->aux->used_maps[i] == (void *)addr)
return prog->aux->used_maps[i];
return NULL;
}
static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog)
{
const struct bpf_map *map;
struct bpf_insn *insns;
u64 imm;
int i;
insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
GFP_USER);
if (!insns)
return insns;
for (i = 0; i < prog->len; i++) {
if (insns[i].code == (BPF_JMP | BPF_TAIL_CALL)) {
insns[i].code = BPF_JMP | BPF_CALL;
insns[i].imm = BPF_FUNC_tail_call;
/* fall-through */
}
if (insns[i].code == (BPF_JMP | BPF_CALL) ||
insns[i].code == (BPF_JMP | BPF_CALL_ARGS)) {
if (insns[i].code == (BPF_JMP | BPF_CALL_ARGS))
insns[i].code = BPF_JMP | BPF_CALL;
if (!bpf_dump_raw_ok())
insns[i].imm = 0;
continue;
}
if (insns[i].code != (BPF_LD | BPF_IMM | BPF_DW))
continue;
imm = ((u64)insns[i + 1].imm << 32) | (u32)insns[i].imm;
map = bpf_map_from_imm(prog, imm);
if (map) {
insns[i].src_reg = BPF_PSEUDO_MAP_FD;
insns[i].imm = map->id;
insns[i + 1].imm = 0;
continue;
}
if (!bpf_dump_raw_ok() &&
imm == (unsigned long)prog->aux) {
insns[i].imm = 0;
insns[i + 1].imm = 0;
continue;
}
}
return insns;
}
static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_prog_info __user *uinfo = u64_to_user_ptr(attr->info.info);
struct bpf_prog_info info = {};
u32 info_len = attr->info.info_len;
char __user *uinsns;
u32 ulen;
int err;
err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
if (err)
return err;
info_len = min_t(u32, sizeof(info), info_len);
if (copy_from_user(&info, uinfo, info_len))
return -EFAULT;
info.type = prog->type;
info.id = prog->aux->id;
info.load_time = prog->aux->load_time;
info.created_by_uid = from_kuid_munged(current_user_ns(),
prog->aux->user->uid);
memcpy(info.tag, prog->tag, sizeof(prog->tag));
memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
ulen = info.nr_map_ids;
info.nr_map_ids = prog->aux->used_map_cnt;
ulen = min_t(u32, info.nr_map_ids, ulen);
if (ulen) {
u32 __user *user_map_ids = u64_to_user_ptr(info.map_ids);
u32 i;
for (i = 0; i < ulen; i++)
if (put_user(prog->aux->used_maps[i]->id,
&user_map_ids[i]))
return -EFAULT;
}
if (!capable(CAP_SYS_ADMIN)) {
info.jited_prog_len = 0;
info.xlated_prog_len = 0;
goto done;
}
ulen = info.xlated_prog_len;
info.xlated_prog_len = bpf_prog_insn_size(prog);
if (info.xlated_prog_len && ulen) {
struct bpf_insn *insns_sanitized;
bool fault;
if (prog->blinded && !bpf_dump_raw_ok()) {
info.xlated_prog_insns = 0;
goto done;
}
insns_sanitized = bpf_insn_prepare_dump(prog);
if (!insns_sanitized)
return -ENOMEM;
uinsns = u64_to_user_ptr(info.xlated_prog_insns);
ulen = min_t(u32, info.xlated_prog_len, ulen);
fault = copy_to_user(uinsns, insns_sanitized, ulen);
kfree(insns_sanitized);
if (fault)
return -EFAULT;
}
if (bpf_prog_is_dev_bound(prog->aux)) {
err = bpf_prog_offload_info_fill(&info, prog);
if (err)
return err;
goto done;
}
/* NOTE: the following code is supposed to be skipped for offload.
* bpf_prog_offload_info_fill() is the place to fill similar fields
* for offload.
*/
ulen = info.jited_prog_len;
info.jited_prog_len = prog->jited_len;
if (info.jited_prog_len && ulen) {
if (bpf_dump_raw_ok()) {
uinsns = u64_to_user_ptr(info.jited_prog_insns);
ulen = min_t(u32, info.jited_prog_len, ulen);
if (copy_to_user(uinsns, prog->bpf_func, ulen))
return -EFAULT;
} else {
info.jited_prog_insns = 0;
}
}
done:
if (copy_to_user(uinfo, &info, info_len) ||
put_user(info_len, &uattr->info.info_len))
return -EFAULT;
return 0;
}
static int bpf_map_get_info_by_fd(struct bpf_map *map,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_map_info __user *uinfo = u64_to_user_ptr(attr->info.info);
struct bpf_map_info info = {};
u32 info_len = attr->info.info_len;
int err;
err = check_uarg_tail_zero(uinfo, sizeof(info), info_len);
if (err)
return err;
info_len = min_t(u32, sizeof(info), info_len);
info.type = map->map_type;
info.id = map->id;
info.key_size = map->key_size;
info.value_size = map->value_size;
info.max_entries = map->max_entries;
info.map_flags = map->map_flags;
memcpy(info.name, map->name, sizeof(map->name));
if (bpf_map_is_dev_bound(map)) {
err = bpf_map_offload_info_fill(&info, map);
if (err)
return err;
}
if (copy_to_user(uinfo, &info, info_len) ||
put_user(info_len, &uattr->info.info_len))
return -EFAULT;
return 0;
}
#define BPF_OBJ_GET_INFO_BY_FD_LAST_FIELD info.info
static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
int ufd = attr->info.bpf_fd;
struct fd f;
int err;
if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
return -EINVAL;
f = fdget(ufd);
if (!f.file)
return -EBADFD;
if (f.file->f_op == &bpf_prog_fops)
err = bpf_prog_get_info_by_fd(f.file->private_data, attr,
uattr);
else if (f.file->f_op == &bpf_map_fops)
err = bpf_map_get_info_by_fd(f.file->private_data, attr,
uattr);
else
err = -EINVAL;
fdput(f);
return err;
}
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
union bpf_attr attr = {};
int err;
if (sysctl_unprivileged_bpf_disabled && !capable(CAP_SYS_ADMIN))
return -EPERM;
err = check_uarg_tail_zero(uattr, sizeof(attr), size);
if (err)
return err;
size = min_t(u32, size, sizeof(attr));
/* copy attributes from user space, may be less than sizeof(bpf_attr) */
if (copy_from_user(&attr, uattr, size) != 0)
return -EFAULT;
err = security_bpf(cmd, &attr, size);
if (err < 0)
return err;
switch (cmd) {
case BPF_MAP_CREATE:
err = map_create(&attr);
break;
case BPF_MAP_LOOKUP_ELEM:
err = map_lookup_elem(&attr);
break;
case BPF_MAP_UPDATE_ELEM:
err = map_update_elem(&attr);
break;
case BPF_MAP_DELETE_ELEM:
err = map_delete_elem(&attr);
break;
case BPF_MAP_GET_NEXT_KEY:
err = map_get_next_key(&attr);
break;
case BPF_PROG_LOAD:
err = bpf_prog_load(&attr);
break;
case BPF_OBJ_PIN:
err = bpf_obj_pin(&attr);
break;
case BPF_OBJ_GET:
err = bpf_obj_get(&attr);
break;
#ifdef CONFIG_CGROUP_BPF
case BPF_PROG_ATTACH:
err = bpf_prog_attach(&attr);
break;
case BPF_PROG_DETACH:
err = bpf_prog_detach(&attr);
break;
case BPF_PROG_QUERY:
err = bpf_prog_query(&attr, uattr);
break;
#endif
case BPF_PROG_TEST_RUN:
err = bpf_prog_test_run(&attr, uattr);
break;
case BPF_PROG_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr,
&prog_idr, &prog_idr_lock);
break;
case BPF_MAP_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr,
&map_idr, &map_idr_lock);
break;
case BPF_PROG_GET_FD_BY_ID:
err = bpf_prog_get_fd_by_id(&attr);
break;
case BPF_MAP_GET_FD_BY_ID:
err = bpf_map_get_fd_by_id(&attr);
break;
case BPF_OBJ_GET_INFO_BY_FD:
err = bpf_obj_get_info_by_fd(&attr, uattr);
break;
case BPF_RAW_TRACEPOINT_OPEN:
err = bpf_raw_tracepoint_open(&attr);
break;
default:
err = -EINVAL;
break;
}
return err;
}
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