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linux/kernel/bpf/syscall.c
Hou Tao 8421d4c876 bpf: Check validity of link->type in bpf_link_show_fdinfo() 
If a newly-added link type doesn't invoke BPF_LINK_TYPE(), accessing
bpf_link_type_strs[link->type] may result in an out-of-bounds access.

To spot such missed invocations early in the future, checking the
validity of link->type in bpf_link_show_fdinfo() and emitting a warning
when such invocations are missed.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20241024013558.1135167-3-houtao@huaweicloud.com
2024-10-24 10:17:12 -07:00

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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
*/
#include <linux/bpf.h>
#include <linux/bpf-cgroup.h>
#include <linux/bpf_trace.h>
#include <linux/bpf_lirc.h>
#include <linux/bpf_verifier.h>
#include <linux/bsearch.h>
#include <linux/btf.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/fdtable.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/license.h>
#include <linux/filter.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>
#include <linux/audit.h>
#include <uapi/linux/btf.h>
#include <linux/pgtable.h>
#include <linux/bpf_lsm.h>
#include <linux/poll.h>
#include <linux/sort.h>
#include <linux/bpf-netns.h>
#include <linux/rcupdate_trace.h>
#include <linux/memcontrol.h>
#include <linux/trace_events.h>
#include <net/netfilter/nf_bpf_link.h>
#include <net/netkit.h>
#include <net/tcx.h>
#define IS_FD_ARRAY(map) ((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_PROG_ARRAY(map) ((map)->map_type == BPF_MAP_TYPE_PROG_ARRAY)
#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_PROG_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);
static DEFINE_IDR(link_idr);
static DEFINE_SPINLOCK(link_idr_lock);
int sysctl_unprivileged_bpf_disabled __read_mostly =
IS_BUILTIN(CONFIG_BPF_UNPRIV_DEFAULT_OFF) ? 2 : 0;
static const struct bpf_map_ops * const bpf_map_types[] = {
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
#define BPF_MAP_TYPE(_id, _ops) \
[_id] = &_ops,
#define BPF_LINK_TYPE(_id, _name)
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
#undef BPF_LINK_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.
*/
int bpf_check_uarg_tail_zero(bpfptr_t uaddr,
size_t expected_size,
size_t actual_size)
{
int res;
if (unlikely(actual_size > PAGE_SIZE)) /* silly large */
return -E2BIG;
if (actual_size <= expected_size)
return 0;
if (uaddr.is_kernel)
res = memchr_inv(uaddr.kernel + expected_size, 0,
actual_size - expected_size) == NULL;
else
res = check_zeroed_user(uaddr.user + expected_size,
actual_size - expected_size);
if (res < 0)
return res;
return res ? 0 : -E2BIG;
}
const struct bpf_map_ops bpf_map_offload_ops = {
.map_meta_equal = bpf_map_meta_equal,
.map_alloc = bpf_map_offload_map_alloc,
.map_free = bpf_map_offload_map_free,
.map_check_btf = map_check_no_btf,
.map_mem_usage = bpf_map_offload_map_mem_usage,
};
static void bpf_map_write_active_inc(struct bpf_map *map)
{
atomic64_inc(&map->writecnt);
}
static void bpf_map_write_active_dec(struct bpf_map *map)
{
atomic64_dec(&map->writecnt);
}
bool bpf_map_write_active(const struct bpf_map *map)
{
return atomic64_read(&map->writecnt) != 0;
}
static u32 bpf_map_value_size(const struct bpf_map *map)
{
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 ||
map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
return round_up(map->value_size, 8) * num_possible_cpus();
else if (IS_FD_MAP(map))
return sizeof(u32);
else
return map->value_size;
}
static void maybe_wait_bpf_programs(struct bpf_map *map)
{
/* Wait for any running non-sleepable BPF programs to complete so that
* userspace, when we return to it, knows that all non-sleepable
* programs that could be running use the new map value. For sleepable
* BPF programs, synchronize_rcu_tasks_trace() should be used to wait
* for the completions of these programs, but considering the waiting
* time can be very long and userspace may think it will hang forever,
* so don't handle sleepable BPF programs now.
*/
if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS ||
map->map_type == BPF_MAP_TYPE_ARRAY_OF_MAPS)
synchronize_rcu();
}
static int bpf_map_update_value(struct bpf_map *map, struct file *map_file,
void *key, void *value, __u64 flags)
{
int err;
/* Need to create a kthread, thus must support schedule */
if (bpf_map_is_offloaded(map)) {
return bpf_map_offload_update_elem(map, key, value, flags);
} else if (map->map_type == BPF_MAP_TYPE_CPUMAP ||
map->map_type == BPF_MAP_TYPE_ARENA ||
map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
return map->ops->map_update_elem(map, key, value, flags);
} else if (map->map_type == BPF_MAP_TYPE_SOCKHASH ||
map->map_type == BPF_MAP_TYPE_SOCKMAP) {
return sock_map_update_elem_sys(map, key, value, flags);
} else if (IS_FD_PROG_ARRAY(map)) {
return bpf_fd_array_map_update_elem(map, map_file, key, value,
flags);
}
bpf_disable_instrumentation();
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, flags);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
err = bpf_percpu_array_update(map, key, value, flags);
} else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) {
err = bpf_percpu_cgroup_storage_update(map, key, value,
flags);
} else if (IS_FD_ARRAY(map)) {
err = bpf_fd_array_map_update_elem(map, map_file, key, value,
flags);
} else if (map->map_type == BPF_MAP_TYPE_HASH_OF_MAPS) {
err = bpf_fd_htab_map_update_elem(map, map_file, key, value,
flags);
} else if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
/* rcu_read_lock() is not needed */
err = bpf_fd_reuseport_array_update_elem(map, key, value,
flags);
} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
map->map_type == BPF_MAP_TYPE_STACK ||
map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
err = map->ops->map_push_elem(map, value, flags);
} else {
rcu_read_lock();
err = map->ops->map_update_elem(map, key, value, flags);
rcu_read_unlock();
}
bpf_enable_instrumentation();
return err;
}
static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value,
__u64 flags)
{
void *ptr;
int err;
if (bpf_map_is_offloaded(map))
return bpf_map_offload_lookup_elem(map, key, value);
bpf_disable_instrumentation();
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_PERCPU_CGROUP_STORAGE) {
err = bpf_percpu_cgroup_storage_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) || IS_FD_PROG_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 if (map->map_type == BPF_MAP_TYPE_REUSEPORT_SOCKARRAY) {
err = bpf_fd_reuseport_array_lookup_elem(map, key, value);
} else if (map->map_type == BPF_MAP_TYPE_QUEUE ||
map->map_type == BPF_MAP_TYPE_STACK ||
map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
err = map->ops->map_peek_elem(map, value);
} else if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
/* struct_ops map requires directly updating "value" */
err = bpf_struct_ops_map_sys_lookup_elem(map, key, value);
} else {
rcu_read_lock();
if (map->ops->map_lookup_elem_sys_only)
ptr = map->ops->map_lookup_elem_sys_only(map, key);
else
ptr = map->ops->map_lookup_elem(map, key);
if (IS_ERR(ptr)) {
err = PTR_ERR(ptr);
} else if (!ptr) {
err = -ENOENT;
} else {
err = 0;
if (flags & BPF_F_LOCK)
/* lock 'ptr' and copy everything but lock */
copy_map_value_locked(map, value, ptr, true);
else
copy_map_value(map, value, ptr);
/* mask lock and timer, since value wasn't zero inited */
check_and_init_map_value(map, value);
}
rcu_read_unlock();
}
bpf_enable_instrumentation();
return err;
}
/* Please, do not use this function outside from the map creation path
* (e.g. in map update path) without taking care of setting the active
* memory cgroup (see at bpf_map_kmalloc_node() for example).
*/
static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
{
/* We really just want to fail instead of triggering OOM killer
* under memory pressure, therefore we set __GFP_NORETRY to kmalloc,
* which is used for lower order allocation requests.
*
* It has been observed that higher order allocation requests done by
* vmalloc with __GFP_NORETRY being set might fail due to not trying
* to reclaim memory from the page cache, thus we set
* __GFP_RETRY_MAYFAIL to avoid such situations.
*/
gfp_t gfp = bpf_memcg_flags(__GFP_NOWARN | __GFP_ZERO);
unsigned int flags = 0;
unsigned long align = 1;
void *area;
if (size >= SIZE_MAX)
return NULL;
/* kmalloc()'ed memory can't be mmap()'ed */
if (mmapable) {
BUG_ON(!PAGE_ALIGNED(size));
align = SHMLBA;
flags = VM_USERMAP;
} else if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
area = kmalloc_node(size, gfp | GFP_USER | __GFP_NORETRY,
numa_node);
if (area != NULL)
return area;
}
return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
gfp | GFP_KERNEL | __GFP_RETRY_MAYFAIL, PAGE_KERNEL,
flags, numa_node, __builtin_return_address(0));
}
void *bpf_map_area_alloc(u64 size, int numa_node)
{
return __bpf_map_area_alloc(size, numa_node, false);
}
void *bpf_map_area_mmapable_alloc(u64 size, int numa_node)
{
return __bpf_map_area_alloc(size, numa_node, true);
}
void bpf_map_area_free(void *area)
{
kvfree(area);
}
static u32 bpf_map_flags_retain_permanent(u32 flags)
{
/* Some map creation flags are not tied to the map object but
* rather to the map fd instead, so they have no meaning upon
* map object inspection since multiple file descriptors with
* different (access) properties can exist here. Thus, given
* this has zero meaning for the map itself, lets clear these
* from here.
*/
return flags & ~(BPF_F_RDONLY | BPF_F_WRONLY);
}
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 = bpf_map_flags_retain_permanent(attr->map_flags);
map->numa_node = bpf_map_attr_numa_node(attr);
map->map_extra = attr->map_extra;
}
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)
{
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;
spin_lock_irqsave(&map_idr_lock, flags);
idr_remove(&map_idr, map->id);
map->id = 0;
spin_unlock_irqrestore(&map_idr_lock, flags);
}
#ifdef CONFIG_MEMCG
static void bpf_map_save_memcg(struct bpf_map *map)
{
/* Currently if a map is created by a process belonging to the root
* memory cgroup, get_obj_cgroup_from_current() will return NULL.
* So we have to check map->objcg for being NULL each time it's
* being used.
*/
if (memcg_bpf_enabled())
map->objcg = get_obj_cgroup_from_current();
}
static void bpf_map_release_memcg(struct bpf_map *map)
{
if (map->objcg)
obj_cgroup_put(map->objcg);
}
static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map)
{
if (map->objcg)
return get_mem_cgroup_from_objcg(map->objcg);
return root_mem_cgroup;
}
void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags,
int node)
{
struct mem_cgroup *memcg, *old_memcg;
void *ptr;
memcg = bpf_map_get_memcg(map);
old_memcg = set_active_memcg(memcg);
ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node);
set_active_memcg(old_memcg);
mem_cgroup_put(memcg);
return ptr;
}
void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags)
{
struct mem_cgroup *memcg, *old_memcg;
void *ptr;
memcg = bpf_map_get_memcg(map);
old_memcg = set_active_memcg(memcg);
ptr = kzalloc(size, flags | __GFP_ACCOUNT);
set_active_memcg(old_memcg);
mem_cgroup_put(memcg);
return ptr;
}
void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size,
gfp_t flags)
{
struct mem_cgroup *memcg, *old_memcg;
void *ptr;
memcg = bpf_map_get_memcg(map);
old_memcg = set_active_memcg(memcg);
ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT);
set_active_memcg(old_memcg);
mem_cgroup_put(memcg);
return ptr;
}
void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size,
size_t align, gfp_t flags)
{
struct mem_cgroup *memcg, *old_memcg;
void __percpu *ptr;
memcg = bpf_map_get_memcg(map);
old_memcg = set_active_memcg(memcg);
ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT);
set_active_memcg(old_memcg);
mem_cgroup_put(memcg);
return ptr;
}
#else
static void bpf_map_save_memcg(struct bpf_map *map)
{
}
static void bpf_map_release_memcg(struct bpf_map *map)
{
}
#endif
int bpf_map_alloc_pages(const struct bpf_map *map, gfp_t gfp, int nid,
unsigned long nr_pages, struct page **pages)
{
unsigned long i, j;
struct page *pg;
int ret = 0;
#ifdef CONFIG_MEMCG
struct mem_cgroup *memcg, *old_memcg;
memcg = bpf_map_get_memcg(map);
old_memcg = set_active_memcg(memcg);
#endif
for (i = 0; i < nr_pages; i++) {
pg = alloc_pages_node(nid, gfp | __GFP_ACCOUNT, 0);
if (pg) {
pages[i] = pg;
continue;
}
for (j = 0; j < i; j++)
__free_page(pages[j]);
ret = -ENOMEM;
break;
}
#ifdef CONFIG_MEMCG
set_active_memcg(old_memcg);
mem_cgroup_put(memcg);
#endif
return ret;
}
static int btf_field_cmp(const void *a, const void *b)
{
const struct btf_field *f1 = a, *f2 = b;
if (f1->offset < f2->offset)
return -1;
else if (f1->offset > f2->offset)
return 1;
return 0;
}
struct btf_field *btf_record_find(const struct btf_record *rec, u32 offset,
u32 field_mask)
{
struct btf_field *field;
if (IS_ERR_OR_NULL(rec) || !(rec->field_mask & field_mask))
return NULL;
field = bsearch(&offset, rec->fields, rec->cnt, sizeof(rec->fields[0]), btf_field_cmp);
if (!field || !(field->type & field_mask))
return NULL;
return field;
}
void btf_record_free(struct btf_record *rec)
{
int i;
if (IS_ERR_OR_NULL(rec))
return;
for (i = 0; i < rec->cnt; i++) {
switch (rec->fields[i].type) {
case BPF_KPTR_UNREF:
case BPF_KPTR_REF:
case BPF_KPTR_PERCPU:
if (rec->fields[i].kptr.module)
module_put(rec->fields[i].kptr.module);
if (btf_is_kernel(rec->fields[i].kptr.btf))
btf_put(rec->fields[i].kptr.btf);
break;
case BPF_LIST_HEAD:
case BPF_LIST_NODE:
case BPF_RB_ROOT:
case BPF_RB_NODE:
case BPF_SPIN_LOCK:
case BPF_TIMER:
case BPF_REFCOUNT:
case BPF_WORKQUEUE:
/* Nothing to release */
break;
default:
WARN_ON_ONCE(1);
continue;
}
}
kfree(rec);
}
void bpf_map_free_record(struct bpf_map *map)
{
btf_record_free(map->record);
map->record = NULL;
}
struct btf_record *btf_record_dup(const struct btf_record *rec)
{
const struct btf_field *fields;
struct btf_record *new_rec;
int ret, size, i;
if (IS_ERR_OR_NULL(rec))
return NULL;
size = offsetof(struct btf_record, fields[rec->cnt]);
new_rec = kmemdup(rec, size, GFP_KERNEL | __GFP_NOWARN);
if (!new_rec)
return ERR_PTR(-ENOMEM);
/* Do a deep copy of the btf_record */
fields = rec->fields;
new_rec->cnt = 0;
for (i = 0; i < rec->cnt; i++) {
switch (fields[i].type) {
case BPF_KPTR_UNREF:
case BPF_KPTR_REF:
case BPF_KPTR_PERCPU:
if (btf_is_kernel(fields[i].kptr.btf))
btf_get(fields[i].kptr.btf);
if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) {
ret = -ENXIO;
goto free;
}
break;
case BPF_LIST_HEAD:
case BPF_LIST_NODE:
case BPF_RB_ROOT:
case BPF_RB_NODE:
case BPF_SPIN_LOCK:
case BPF_TIMER:
case BPF_REFCOUNT:
case BPF_WORKQUEUE:
/* Nothing to acquire */
break;
default:
ret = -EFAULT;
WARN_ON_ONCE(1);
goto free;
}
new_rec->cnt++;
}
return new_rec;
free:
btf_record_free(new_rec);
return ERR_PTR(ret);
}
bool btf_record_equal(const struct btf_record *rec_a, const struct btf_record *rec_b)
{
bool a_has_fields = !IS_ERR_OR_NULL(rec_a), b_has_fields = !IS_ERR_OR_NULL(rec_b);
int size;
if (!a_has_fields && !b_has_fields)
return true;
if (a_has_fields != b_has_fields)
return false;
if (rec_a->cnt != rec_b->cnt)
return false;
size = offsetof(struct btf_record, fields[rec_a->cnt]);
/* btf_parse_fields uses kzalloc to allocate a btf_record, so unused
* members are zeroed out. So memcmp is safe to do without worrying
* about padding/unused fields.
*
* While spin_lock, timer, and kptr have no relation to map BTF,
* list_head metadata is specific to map BTF, the btf and value_rec
* members in particular. btf is the map BTF, while value_rec points to
* btf_record in that map BTF.
*
* So while by default, we don't rely on the map BTF (which the records
* were parsed from) matching for both records, which is not backwards
* compatible, in case list_head is part of it, we implicitly rely on
* that by way of depending on memcmp succeeding for it.
*/
return !memcmp(rec_a, rec_b, size);
}
void bpf_obj_free_timer(const struct btf_record *rec, void *obj)
{
if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_TIMER)))
return;
bpf_timer_cancel_and_free(obj + rec->timer_off);
}
void bpf_obj_free_workqueue(const struct btf_record *rec, void *obj)
{
if (WARN_ON_ONCE(!btf_record_has_field(rec, BPF_WORKQUEUE)))
return;
bpf_wq_cancel_and_free(obj + rec->wq_off);
}
void bpf_obj_free_fields(const struct btf_record *rec, void *obj)
{
const struct btf_field *fields;
int i;
if (IS_ERR_OR_NULL(rec))
return;
fields = rec->fields;
for (i = 0; i < rec->cnt; i++) {
struct btf_struct_meta *pointee_struct_meta;
const struct btf_field *field = &fields[i];
void *field_ptr = obj + field->offset;
void *xchgd_field;
switch (fields[i].type) {
case BPF_SPIN_LOCK:
break;
case BPF_TIMER:
bpf_timer_cancel_and_free(field_ptr);
break;
case BPF_WORKQUEUE:
bpf_wq_cancel_and_free(field_ptr);
break;
case BPF_KPTR_UNREF:
WRITE_ONCE(*(u64 *)field_ptr, 0);
break;
case BPF_KPTR_REF:
case BPF_KPTR_PERCPU:
xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0);
if (!xchgd_field)
break;
if (!btf_is_kernel(field->kptr.btf)) {
pointee_struct_meta = btf_find_struct_meta(field->kptr.btf,
field->kptr.btf_id);
migrate_disable();
__bpf_obj_drop_impl(xchgd_field, pointee_struct_meta ?
pointee_struct_meta->record : NULL,
fields[i].type == BPF_KPTR_PERCPU);
migrate_enable();
} else {
field->kptr.dtor(xchgd_field);
}
break;
case BPF_LIST_HEAD:
if (WARN_ON_ONCE(rec->spin_lock_off < 0))
continue;
bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off);
break;
case BPF_RB_ROOT:
if (WARN_ON_ONCE(rec->spin_lock_off < 0))
continue;
bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off);
break;
case BPF_LIST_NODE:
case BPF_RB_NODE:
case BPF_REFCOUNT:
break;
default:
WARN_ON_ONCE(1);
continue;
}
}
}
static void bpf_map_free(struct bpf_map *map)
{
struct btf_record *rec = map->record;
struct btf *btf = map->btf;
/* implementation dependent freeing */
map->ops->map_free(map);
/* Delay freeing of btf_record for maps, as map_free
* callback usually needs access to them. It is better to do it here
* than require each callback to do the free itself manually.
*
* Note that the btf_record stashed in map->inner_map_meta->record was
* already freed using the map_free callback for map in map case which
* eventually calls bpf_map_free_meta, since inner_map_meta is only a
* template bpf_map struct used during verification.
*/
btf_record_free(rec);
/* Delay freeing of btf for maps, as map_free callback may need
* struct_meta info which will be freed with btf_put().
*/
btf_put(btf);
}
/* called from workqueue */
static void bpf_map_free_deferred(struct work_struct *work)
{
struct bpf_map *map = container_of(work, struct bpf_map, work);
security_bpf_map_free(map);
bpf_map_release_memcg(map);
bpf_map_free(map);
}
static void bpf_map_put_uref(struct bpf_map *map)
{
if (atomic64_dec_and_test(&map->usercnt)) {
if (map->ops->map_release_uref)
map->ops->map_release_uref(map);
}
}
static void bpf_map_free_in_work(struct bpf_map *map)
{
INIT_WORK(&map->work, bpf_map_free_deferred);
/* Avoid spawning kworkers, since they all might contend
* for the same mutex like slab_mutex.
*/
queue_work(system_unbound_wq, &map->work);
}
static void bpf_map_free_rcu_gp(struct rcu_head *rcu)
{
bpf_map_free_in_work(container_of(rcu, struct bpf_map, rcu));
}
static void bpf_map_free_mult_rcu_gp(struct rcu_head *rcu)
{
if (rcu_trace_implies_rcu_gp())
bpf_map_free_rcu_gp(rcu);
else
call_rcu(rcu, bpf_map_free_rcu_gp);
}
/* decrement map refcnt and schedule it for freeing via workqueue
* (underlying map implementation ops->map_free() might sleep)
*/
void bpf_map_put(struct bpf_map *map)
{
if (atomic64_dec_and_test(&map->refcnt)) {
/* bpf_map_free_id() must be called first */
bpf_map_free_id(map);
WARN_ON_ONCE(atomic64_read(&map->sleepable_refcnt));
if (READ_ONCE(map->free_after_mult_rcu_gp))
call_rcu_tasks_trace(&map->rcu, bpf_map_free_mult_rcu_gp);
else if (READ_ONCE(map->free_after_rcu_gp))
call_rcu(&map->rcu, bpf_map_free_rcu_gp);
else
bpf_map_free_in_work(map);
}
}
EXPORT_SYMBOL_GPL(bpf_map_put);
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;
}
static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
{
fmode_t mode = fd_file(f)->f_mode;
/* Our file permissions may have been overridden by global
* map permissions facing syscall side.
*/
if (READ_ONCE(map->frozen))
mode &= ~FMODE_CAN_WRITE;
return mode;
}
#ifdef CONFIG_PROC_FS
/* Show the memory usage of a bpf map */
static u64 bpf_map_memory_usage(const struct bpf_map *map)
{
return map->ops->map_mem_usage(map);
}
static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
{
struct bpf_map *map = filp->private_data;
u32 type = 0, jited = 0;
if (map_type_contains_progs(map)) {
spin_lock(&map->owner.lock);
type = map->owner.type;
jited = map->owner.jited;
spin_unlock(&map->owner.lock);
}
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"
"map_extra:\t%#llx\n"
"memlock:\t%llu\n"
"map_id:\t%u\n"
"frozen:\t%u\n",
map->map_type,
map->key_size,
map->value_size,
map->max_entries,
map->map_flags,
(unsigned long long)map->map_extra,
bpf_map_memory_usage(map),
map->id,
READ_ONCE(map->frozen));
if (type) {
seq_printf(m, "owner_prog_type:\t%u\n", type);
seq_printf(m, "owner_jited:\t%u\n", 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;
}
/* called for any extra memory-mapped regions (except initial) */
static void bpf_map_mmap_open(struct vm_area_struct *vma)
{
struct bpf_map *map = vma->vm_file->private_data;
if (vma->vm_flags & VM_MAYWRITE)
bpf_map_write_active_inc(map);
}
/* called for all unmapped memory region (including initial) */
static void bpf_map_mmap_close(struct vm_area_struct *vma)
{
struct bpf_map *map = vma->vm_file->private_data;
if (vma->vm_flags & VM_MAYWRITE)
bpf_map_write_active_dec(map);
}
static const struct vm_operations_struct bpf_map_default_vmops = {
.open = bpf_map_mmap_open,
.close = bpf_map_mmap_close,
};
static int bpf_map_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct bpf_map *map = filp->private_data;
int err;
if (!map->ops->map_mmap || !IS_ERR_OR_NULL(map->record))
return -ENOTSUPP;
if (!(vma->vm_flags & VM_SHARED))
return -EINVAL;
mutex_lock(&map->freeze_mutex);
if (vma->vm_flags & VM_WRITE) {
if (map->frozen) {
err = -EPERM;
goto out;
}
/* map is meant to be read-only, so do not allow mapping as
* writable, because it's possible to leak a writable page
* reference and allows user-space to still modify it after
* freezing, while verifier will assume contents do not change
*/
if (map->map_flags & BPF_F_RDONLY_PROG) {
err = -EACCES;
goto out;
}
}
/* set default open/close callbacks */
vma->vm_ops = &bpf_map_default_vmops;
vma->vm_private_data = map;
vm_flags_clear(vma, VM_MAYEXEC);
if (!(vma->vm_flags & VM_WRITE))
/* disallow re-mapping with PROT_WRITE */
vm_flags_clear(vma, VM_MAYWRITE);
err = map->ops->map_mmap(map, vma);
if (err)
goto out;
if (vma->vm_flags & VM_MAYWRITE)
bpf_map_write_active_inc(map);
out:
mutex_unlock(&map->freeze_mutex);
return err;
}
static __poll_t bpf_map_poll(struct file *filp, struct poll_table_struct *pts)
{
struct bpf_map *map = filp->private_data;
if (map->ops->map_poll)
return map->ops->map_poll(map, filp, pts);
return EPOLLERR;
}
static unsigned long bpf_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff,
unsigned long flags)
{
struct bpf_map *map = filp->private_data;
if (map->ops->map_get_unmapped_area)
return map->ops->map_get_unmapped_area(filp, addr, len, pgoff, flags);
#ifdef CONFIG_MMU
return mm_get_unmapped_area(current->mm, filp, addr, len, pgoff, flags);
#else
return addr;
#endif
}
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,
.mmap = bpf_map_mmap,
.poll = bpf_map_poll,
.get_unmapped_area = bpf_get_unmapped_area,
};
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 "size" number of bytes.
* Return strlen on success and < 0 on error.
*/
int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size)
{
const char *end = src + size;
const char *orig_src = src;
memset(dst, 0, size);
/* Copy all isalnum(), '_' and '.' chars. */
while (src < end && *src) {
if (!isalnum(*src) &&
*src != '_' && *src != '.')
return -EINVAL;
*dst++ = *src++;
}
/* No '\0' found in "size" number of bytes */
if (src == end)
return -EINVAL;
return src - orig_src;
}
int map_check_no_btf(const struct bpf_map *map,
const struct btf *btf,
const struct btf_type *key_type,
const struct btf_type *value_type)
{
return -ENOTSUPP;
}
static int map_check_btf(struct bpf_map *map, struct bpf_token *token,
const struct btf *btf, u32 btf_key_id, u32 btf_value_id)
{
const struct btf_type *key_type, *value_type;
u32 key_size, value_size;
int ret = 0;
/* Some maps allow key to be unspecified. */
if (btf_key_id) {
key_type = btf_type_id_size(btf, &btf_key_id, &key_size);
if (!key_type || key_size != map->key_size)
return -EINVAL;
} else {
key_type = btf_type_by_id(btf, 0);
if (!map->ops->map_check_btf)
return -EINVAL;
}
value_type = btf_type_id_size(btf, &btf_value_id, &value_size);
if (!value_type || value_size != map->value_size)
return -EINVAL;
map->record = btf_parse_fields(btf, value_type,
BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD |
BPF_RB_ROOT | BPF_REFCOUNT | BPF_WORKQUEUE,
map->value_size);
if (!IS_ERR_OR_NULL(map->record)) {
int i;
if (!bpf_token_capable(token, CAP_BPF)) {
ret = -EPERM;
goto free_map_tab;
}
if (map->map_flags & (BPF_F_RDONLY_PROG | BPF_F_WRONLY_PROG)) {
ret = -EACCES;
goto free_map_tab;
}
for (i = 0; i < sizeof(map->record->field_mask) * 8; i++) {
switch (map->record->field_mask & (1 << i)) {
case 0:
continue;
case BPF_SPIN_LOCK:
if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY &&
map->map_type != BPF_MAP_TYPE_CGROUP_STORAGE &&
map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
ret = -EOPNOTSUPP;
goto free_map_tab;
}
break;
case BPF_TIMER:
case BPF_WORKQUEUE:
if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_LRU_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY) {
ret = -EOPNOTSUPP;
goto free_map_tab;
}
break;
case BPF_KPTR_UNREF:
case BPF_KPTR_REF:
case BPF_KPTR_PERCPU:
case BPF_REFCOUNT:
if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_PERCPU_HASH &&
map->map_type != BPF_MAP_TYPE_LRU_HASH &&
map->map_type != BPF_MAP_TYPE_LRU_PERCPU_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY &&
map->map_type != BPF_MAP_TYPE_PERCPU_ARRAY &&
map->map_type != BPF_MAP_TYPE_SK_STORAGE &&
map->map_type != BPF_MAP_TYPE_INODE_STORAGE &&
map->map_type != BPF_MAP_TYPE_TASK_STORAGE &&
map->map_type != BPF_MAP_TYPE_CGRP_STORAGE) {
ret = -EOPNOTSUPP;
goto free_map_tab;
}
break;
case BPF_LIST_HEAD:
case BPF_RB_ROOT:
if (map->map_type != BPF_MAP_TYPE_HASH &&
map->map_type != BPF_MAP_TYPE_LRU_HASH &&
map->map_type != BPF_MAP_TYPE_ARRAY) {
ret = -EOPNOTSUPP;
goto free_map_tab;
}
break;
default:
/* Fail if map_type checks are missing for a field type */
ret = -EOPNOTSUPP;
goto free_map_tab;
}
}
}
ret = btf_check_and_fixup_fields(btf, map->record);
if (ret < 0)
goto free_map_tab;
if (map->ops->map_check_btf) {
ret = map->ops->map_check_btf(map, btf, key_type, value_type);
if (ret < 0)
goto free_map_tab;
}
return ret;
free_map_tab:
bpf_map_free_record(map);
return ret;
}
static bool bpf_net_capable(void)
{
return capable(CAP_NET_ADMIN) || capable(CAP_SYS_ADMIN);
}
#define BPF_MAP_CREATE_LAST_FIELD map_token_fd
/* called via syscall */
static int map_create(union bpf_attr *attr)
{
const struct bpf_map_ops *ops;
struct bpf_token *token = NULL;
int numa_node = bpf_map_attr_numa_node(attr);
u32 map_type = attr->map_type;
struct bpf_map *map;
bool token_flag;
int f_flags;
int err;
err = CHECK_ATTR(BPF_MAP_CREATE);
if (err)
return -EINVAL;
/* check BPF_F_TOKEN_FD flag, remember if it's set, and then clear it
* to avoid per-map type checks tripping on unknown flag
*/
token_flag = attr->map_flags & BPF_F_TOKEN_FD;
attr->map_flags &= ~BPF_F_TOKEN_FD;
if (attr->btf_vmlinux_value_type_id) {
if (attr->map_type != BPF_MAP_TYPE_STRUCT_OPS ||
attr->btf_key_type_id || attr->btf_value_type_id)
return -EINVAL;
} else if (attr->btf_key_type_id && !attr->btf_value_type_id) {
return -EINVAL;
}
if (attr->map_type != BPF_MAP_TYPE_BLOOM_FILTER &&
attr->map_type != BPF_MAP_TYPE_ARENA &&
attr->map_extra != 0)
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_type = attr->map_type;
if (map_type >= ARRAY_SIZE(bpf_map_types))
return -EINVAL;
map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
ops = bpf_map_types[map_type];
if (!ops)
return -EINVAL;
if (ops->map_alloc_check) {
err = ops->map_alloc_check(attr);
if (err)
return err;
}
if (attr->map_ifindex)
ops = &bpf_map_offload_ops;
if (!ops->map_mem_usage)
return -EINVAL;
if (token_flag) {
token = bpf_token_get_from_fd(attr->map_token_fd);
if (IS_ERR(token))
return PTR_ERR(token);
/* if current token doesn't grant map creation permissions,
* then we can't use this token, so ignore it and rely on
* system-wide capabilities checks
*/
if (!bpf_token_allow_cmd(token, BPF_MAP_CREATE) ||
!bpf_token_allow_map_type(token, attr->map_type)) {
bpf_token_put(token);
token = NULL;
}
}
err = -EPERM;
/* Intent here is for unprivileged_bpf_disabled to block BPF map
* creation for unprivileged users; other actions depend
* on fd availability and access to bpffs, so are dependent on
* object creation success. Even with unprivileged BPF disabled,
* capability checks are still carried out.
*/
if (sysctl_unprivileged_bpf_disabled && !bpf_token_capable(token, CAP_BPF))
goto put_token;
/* check privileged map type permissions */
switch (map_type) {
case BPF_MAP_TYPE_ARRAY:
case BPF_MAP_TYPE_PERCPU_ARRAY:
case BPF_MAP_TYPE_PROG_ARRAY:
case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
case BPF_MAP_TYPE_CGROUP_ARRAY:
case BPF_MAP_TYPE_ARRAY_OF_MAPS:
case BPF_MAP_TYPE_HASH:
case BPF_MAP_TYPE_PERCPU_HASH:
case BPF_MAP_TYPE_HASH_OF_MAPS:
case BPF_MAP_TYPE_RINGBUF:
case BPF_MAP_TYPE_USER_RINGBUF:
case BPF_MAP_TYPE_CGROUP_STORAGE:
case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
/* unprivileged */
break;
case BPF_MAP_TYPE_SK_STORAGE:
case BPF_MAP_TYPE_INODE_STORAGE:
case BPF_MAP_TYPE_TASK_STORAGE:
case BPF_MAP_TYPE_CGRP_STORAGE:
case BPF_MAP_TYPE_BLOOM_FILTER:
case BPF_MAP_TYPE_LPM_TRIE:
case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
case BPF_MAP_TYPE_STACK_TRACE:
case BPF_MAP_TYPE_QUEUE:
case BPF_MAP_TYPE_STACK:
case BPF_MAP_TYPE_LRU_HASH:
case BPF_MAP_TYPE_LRU_PERCPU_HASH:
case BPF_MAP_TYPE_STRUCT_OPS:
case BPF_MAP_TYPE_CPUMAP:
case BPF_MAP_TYPE_ARENA:
if (!bpf_token_capable(token, CAP_BPF))
goto put_token;
break;
case BPF_MAP_TYPE_SOCKMAP:
case BPF_MAP_TYPE_SOCKHASH:
case BPF_MAP_TYPE_DEVMAP:
case BPF_MAP_TYPE_DEVMAP_HASH:
case BPF_MAP_TYPE_XSKMAP:
if (!bpf_token_capable(token, CAP_NET_ADMIN))
goto put_token;
break;
default:
WARN(1, "unsupported map type %d", map_type);
goto put_token;
}
map = ops->map_alloc(attr);
if (IS_ERR(map)) {
err = PTR_ERR(map);
goto put_token;
}
map->ops = ops;
map->map_type = map_type;
err = bpf_obj_name_cpy(map->name, attr->map_name,
sizeof(attr->map_name));
if (err < 0)
goto free_map;
atomic64_set(&map->refcnt, 1);
atomic64_set(&map->usercnt, 1);
mutex_init(&map->freeze_mutex);
spin_lock_init(&map->owner.lock);
if (attr->btf_key_type_id || attr->btf_value_type_id ||
/* Even the map's value is a kernel's struct,
* the bpf_prog.o must have BTF to begin with
* to figure out the corresponding kernel's
* counter part. Thus, attr->btf_fd has
* to be valid also.
*/
attr->btf_vmlinux_value_type_id) {
struct btf *btf;
btf = btf_get_by_fd(attr->btf_fd);
if (IS_ERR(btf)) {
err = PTR_ERR(btf);
goto free_map;
}
if (btf_is_kernel(btf)) {
btf_put(btf);
err = -EACCES;
goto free_map;
}
map->btf = btf;
if (attr->btf_value_type_id) {
err = map_check_btf(map, token, btf, attr->btf_key_type_id,
attr->btf_value_type_id);
if (err)
goto free_map;
}
map->btf_key_type_id = attr->btf_key_type_id;
map->btf_value_type_id = attr->btf_value_type_id;
map->btf_vmlinux_value_type_id =
attr->btf_vmlinux_value_type_id;
}
err = security_bpf_map_create(map, attr, token);
if (err)
goto free_map_sec;
err = bpf_map_alloc_id(map);
if (err)
goto free_map_sec;
bpf_map_save_memcg(map);
bpf_token_put(token);
err = bpf_map_new_fd(map, f_flags);
if (err < 0) {
/* failed to allocate fd.
* bpf_map_put_with_uref() 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_with_uref(map);
return err;
}
return err;
free_map_sec:
security_bpf_map_free(map);
free_map:
bpf_map_free(map);
put_token:
bpf_token_put(token);
return err;
}
void bpf_map_inc(struct bpf_map *map)
{
atomic64_inc(&map->refcnt);
}
EXPORT_SYMBOL_GPL(bpf_map_inc);
void bpf_map_inc_with_uref(struct bpf_map *map)
{
atomic64_inc(&map->refcnt);
atomic64_inc(&map->usercnt);
}
EXPORT_SYMBOL_GPL(bpf_map_inc_with_uref);
struct bpf_map *bpf_map_get(u32 ufd)
{
CLASS(fd, f)(ufd);
struct bpf_map *map = __bpf_map_get(f);
if (!IS_ERR(map))
bpf_map_inc(map);
return map;
}
EXPORT_SYMBOL(bpf_map_get);
struct bpf_map *bpf_map_get_with_uref(u32 ufd)
{
CLASS(fd, f)(ufd);
struct bpf_map *map = __bpf_map_get(f);
if (!IS_ERR(map))
bpf_map_inc_with_uref(map);
return map;
}
/* map_idr_lock should have been held or the map should have been
* protected by rcu read lock.
*/
struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
{
int refold;
refold = atomic64_fetch_add_unless(&map->refcnt, 1, 0);
if (!refold)
return ERR_PTR(-ENOENT);
if (uref)
atomic64_inc(&map->usercnt);
return map;
}
struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map)
{
spin_lock_bh(&map_idr_lock);
map = __bpf_map_inc_not_zero(map, false);
spin_unlock_bh(&map_idr_lock);
return map;
}
EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
{
return -ENOTSUPP;
}
static void *__bpf_copy_key(void __user *ukey, u64 key_size)
{
if (key_size)
return vmemdup_user(ukey, key_size);
if (ukey)
return ERR_PTR(-EINVAL);
return NULL;
}
static void *___bpf_copy_key(bpfptr_t ukey, u64 key_size)
{
if (key_size)
return kvmemdup_bpfptr(ukey, key_size);
if (!bpfptr_is_null(ukey))
return ERR_PTR(-EINVAL);
return NULL;
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_MAP_LOOKUP_ELEM_LAST_FIELD flags
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);
struct bpf_map *map;
void *key, *value;
u32 value_size;
int err;
if (CHECK_ATTR(BPF_MAP_LOOKUP_ELEM))
return -EINVAL;
if (attr->flags & ~BPF_F_LOCK)
return -EINVAL;
CLASS(fd, f)(attr->map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
return -EPERM;
if ((attr->flags & BPF_F_LOCK) &&
!btf_record_has_field(map->record, BPF_SPIN_LOCK))
return -EINVAL;
key = __bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key))
return PTR_ERR(key);
value_size = bpf_map_value_size(map);
err = -ENOMEM;
value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
if (map->map_type == BPF_MAP_TYPE_BLOOM_FILTER) {
if (copy_from_user(value, uvalue, value_size))
err = -EFAULT;
else
err = bpf_map_copy_value(map, key, value, attr->flags);
goto free_value;
}
err = bpf_map_copy_value(map, key, value, attr->flags);
if (err)
goto free_value;
err = -EFAULT;
if (copy_to_user(uvalue, value, value_size) != 0)
goto free_value;
err = 0;
free_value:
kvfree(value);
free_key:
kvfree(key);
return err;
}
#define BPF_MAP_UPDATE_ELEM_LAST_FIELD flags
static int map_update_elem(union bpf_attr *attr, bpfptr_t uattr)
{
bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
bpfptr_t uvalue = make_bpfptr(attr->value, uattr.is_kernel);
struct bpf_map *map;
void *key, *value;
u32 value_size;
int err;
if (CHECK_ATTR(BPF_MAP_UPDATE_ELEM))
return -EINVAL;
CLASS(fd, f)(attr->map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
bpf_map_write_active_inc(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
if ((attr->flags & BPF_F_LOCK) &&
!btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
err = -EINVAL;
goto err_put;
}
key = ___bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
value_size = bpf_map_value_size(map);
value = kvmemdup_bpfptr(uvalue, value_size);
if (IS_ERR(value)) {
err = PTR_ERR(value);
goto free_key;
}
err = bpf_map_update_value(map, fd_file(f), key, value, attr->flags);
if (!err)
maybe_wait_bpf_programs(map);
kvfree(value);
free_key:
kvfree(key);
err_put:
bpf_map_write_active_dec(map);
return err;
}
#define BPF_MAP_DELETE_ELEM_LAST_FIELD key
static int map_delete_elem(union bpf_attr *attr, bpfptr_t uattr)
{
bpfptr_t ukey = make_bpfptr(attr->key, uattr.is_kernel);
struct bpf_map *map;
void *key;
int err;
if (CHECK_ATTR(BPF_MAP_DELETE_ELEM))
return -EINVAL;
CLASS(fd, f)(attr->map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
bpf_map_write_active_inc(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
key = ___bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
if (bpf_map_is_offloaded(map)) {
err = bpf_map_offload_delete_elem(map, key);
goto out;
} else if (IS_FD_PROG_ARRAY(map) ||
map->map_type == BPF_MAP_TYPE_STRUCT_OPS) {
/* These maps require sleepable context */
err = map->ops->map_delete_elem(map, key);
goto out;
}
bpf_disable_instrumentation();
rcu_read_lock();
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
bpf_enable_instrumentation();
if (!err)
maybe_wait_bpf_programs(map);
out:
kvfree(key);
err_put:
bpf_map_write_active_dec(map);
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);
struct bpf_map *map;
void *key, *next_key;
int err;
if (CHECK_ATTR(BPF_MAP_GET_NEXT_KEY))
return -EINVAL;
CLASS(fd, f)(attr->map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ))
return -EPERM;
if (ukey) {
key = __bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key))
return PTR_ERR(key);
} else {
key = NULL;
}
err = -ENOMEM;
next_key = kvmalloc(map->key_size, GFP_USER);
if (!next_key)
goto free_key;
if (bpf_map_is_offloaded(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;
err = 0;
free_next_key:
kvfree(next_key);
free_key:
kvfree(key);
return err;
}
int generic_map_delete_batch(struct bpf_map *map,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
void __user *keys = u64_to_user_ptr(attr->batch.keys);
u32 cp, max_count;
int err = 0;
void *key;
if (attr->batch.elem_flags & ~BPF_F_LOCK)
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
!btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
return -EINVAL;
}
max_count = attr->batch.count;
if (!max_count)
return 0;
if (put_user(0, &uattr->batch.count))
return -EFAULT;
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
for (cp = 0; cp < max_count; cp++) {
err = -EFAULT;
if (copy_from_user(key, keys + cp * map->key_size,
map->key_size))
break;
if (bpf_map_is_offloaded(map)) {
err = bpf_map_offload_delete_elem(map, key);
break;
}
bpf_disable_instrumentation();
rcu_read_lock();
err = map->ops->map_delete_elem(map, key);
rcu_read_unlock();
bpf_enable_instrumentation();
if (err)
break;
cond_resched();
}
if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
err = -EFAULT;
kvfree(key);
return err;
}
int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
void __user *values = u64_to_user_ptr(attr->batch.values);
void __user *keys = u64_to_user_ptr(attr->batch.keys);
u32 value_size, cp, max_count;
void *key, *value;
int err = 0;
if (attr->batch.elem_flags & ~BPF_F_LOCK)
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
!btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
return -EINVAL;
}
value_size = bpf_map_value_size(map);
max_count = attr->batch.count;
if (!max_count)
return 0;
if (put_user(0, &uattr->batch.count))
return -EFAULT;
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value) {
kvfree(key);
return -ENOMEM;
}
for (cp = 0; cp < max_count; cp++) {
err = -EFAULT;
if (copy_from_user(key, keys + cp * map->key_size,
map->key_size) ||
copy_from_user(value, values + cp * value_size, value_size))
break;
err = bpf_map_update_value(map, map_file, key, value,
attr->batch.elem_flags);
if (err)
break;
cond_resched();
}
if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))
err = -EFAULT;
kvfree(value);
kvfree(key);
return err;
}
#define MAP_LOOKUP_RETRIES 3
int generic_map_lookup_batch(struct bpf_map *map,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
void __user *uobatch = u64_to_user_ptr(attr->batch.out_batch);
void __user *ubatch = u64_to_user_ptr(attr->batch.in_batch);
void __user *values = u64_to_user_ptr(attr->batch.values);
void __user *keys = u64_to_user_ptr(attr->batch.keys);
void *buf, *buf_prevkey, *prev_key, *key, *value;
int err, retry = MAP_LOOKUP_RETRIES;
u32 value_size, cp, max_count;
if (attr->batch.elem_flags & ~BPF_F_LOCK)
return -EINVAL;
if ((attr->batch.elem_flags & BPF_F_LOCK) &&
!btf_record_has_field(map->record, BPF_SPIN_LOCK))
return -EINVAL;
value_size = bpf_map_value_size(map);
max_count = attr->batch.count;
if (!max_count)
return 0;
if (put_user(0, &uattr->batch.count))
return -EFAULT;
buf_prevkey = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!buf_prevkey)
return -ENOMEM;
buf = kvmalloc(map->key_size + value_size, GFP_USER | __GFP_NOWARN);
if (!buf) {
kvfree(buf_prevkey);
return -ENOMEM;
}
err = -EFAULT;
prev_key = NULL;
if (ubatch && copy_from_user(buf_prevkey, ubatch, map->key_size))
goto free_buf;
key = buf;
value = key + map->key_size;
if (ubatch)
prev_key = buf_prevkey;
for (cp = 0; cp < max_count;) {
rcu_read_lock();
err = map->ops->map_get_next_key(map, prev_key, key);
rcu_read_unlock();
if (err)
break;
err = bpf_map_copy_value(map, key, value,
attr->batch.elem_flags);
if (err == -ENOENT) {
if (retry) {
retry--;
continue;
}
err = -EINTR;
break;
}
if (err)
goto free_buf;
if (copy_to_user(keys + cp * map->key_size, key,
map->key_size)) {
err = -EFAULT;
goto free_buf;
}
if (copy_to_user(values + cp * value_size, value, value_size)) {
err = -EFAULT;
goto free_buf;
}
if (!prev_key)
prev_key = buf_prevkey;
swap(prev_key, key);
retry = MAP_LOOKUP_RETRIES;
cp++;
cond_resched();
}
if (err == -EFAULT)
goto free_buf;
if ((copy_to_user(&uattr->batch.count, &cp, sizeof(cp)) ||
(cp && copy_to_user(uobatch, prev_key, map->key_size))))
err = -EFAULT;
free_buf:
kvfree(buf_prevkey);
kvfree(buf);
return err;
}
#define BPF_MAP_LOOKUP_AND_DELETE_ELEM_LAST_FIELD flags
static int map_lookup_and_delete_elem(union bpf_attr *attr)
{
void __user *ukey = u64_to_user_ptr(attr->key);
void __user *uvalue = u64_to_user_ptr(attr->value);
struct bpf_map *map;
void *key, *value;
u32 value_size;
int err;
if (CHECK_ATTR(BPF_MAP_LOOKUP_AND_DELETE_ELEM))
return -EINVAL;
if (attr->flags & ~BPF_F_LOCK)
return -EINVAL;
CLASS(fd, f)(attr->map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
bpf_map_write_active_inc(map);
if (!(map_get_sys_perms(map, f) & FMODE_CAN_READ) ||
!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
if (attr->flags &&
(map->map_type == BPF_MAP_TYPE_QUEUE ||
map->map_type == BPF_MAP_TYPE_STACK)) {
err = -EINVAL;
goto err_put;
}
if ((attr->flags & BPF_F_LOCK) &&
!btf_record_has_field(map->record, BPF_SPIN_LOCK)) {
err = -EINVAL;
goto err_put;
}
key = __bpf_copy_key(ukey, map->key_size);
if (IS_ERR(key)) {
err = PTR_ERR(key);
goto err_put;
}
value_size = bpf_map_value_size(map);
err = -ENOMEM;
value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
err = -ENOTSUPP;
if (map->map_type == BPF_MAP_TYPE_QUEUE ||
map->map_type == BPF_MAP_TYPE_STACK) {
err = map->ops->map_pop_elem(map, value);
} else if (map->map_type == BPF_MAP_TYPE_HASH ||
map->map_type == BPF_MAP_TYPE_PERCPU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_HASH ||
map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
if (!bpf_map_is_offloaded(map)) {
bpf_disable_instrumentation();
rcu_read_lock();
err = map->ops->map_lookup_and_delete_elem(map, key, value, attr->flags);
rcu_read_unlock();
bpf_enable_instrumentation();
}
}
if (err)
goto free_value;
if (copy_to_user(uvalue, value, value_size) != 0) {
err = -EFAULT;
goto free_value;
}
err = 0;
free_value:
kvfree(value);
free_key:
kvfree(key);
err_put:
bpf_map_write_active_dec(map);
return err;
}
#define BPF_MAP_FREEZE_LAST_FIELD map_fd
static int map_freeze(const union bpf_attr *attr)
{
int err = 0;
struct bpf_map *map;
if (CHECK_ATTR(BPF_MAP_FREEZE))
return -EINVAL;
CLASS(fd, f)(attr->map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS || !IS_ERR_OR_NULL(map->record))
return -ENOTSUPP;
if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE))
return -EPERM;
mutex_lock(&map->freeze_mutex);
if (bpf_map_write_active(map)) {
err = -EBUSY;
goto err_put;
}
if (READ_ONCE(map->frozen)) {
err = -EBUSY;
goto err_put;
}
WRITE_ONCE(map->frozen, true);
err_put:
mutex_unlock(&map->freeze_mutex);
return err;
}
static const struct bpf_prog_ops * const bpf_prog_types[] = {
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type) \
[_id] = & _name ## _prog_ops,
#define BPF_MAP_TYPE(_id, _ops)
#define BPF_LINK_TYPE(_id, _name)
#include <linux/bpf_types.h>
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
#undef BPF_LINK_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_offloaded(prog->aux))
prog->aux->ops = ops;
else
prog->aux->ops = &bpf_offload_prog_ops;
prog->type = type;
return 0;
}
enum bpf_audit {
BPF_AUDIT_LOAD,
BPF_AUDIT_UNLOAD,
BPF_AUDIT_MAX,
};
static const char * const bpf_audit_str[BPF_AUDIT_MAX] = {
[BPF_AUDIT_LOAD] = "LOAD",
[BPF_AUDIT_UNLOAD] = "UNLOAD",
};
static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op)
{
struct audit_context *ctx = NULL;
struct audit_buffer *ab;
if (WARN_ON_ONCE(op >= BPF_AUDIT_MAX))
return;
if (audit_enabled == AUDIT_OFF)
return;
if (!in_irq() && !irqs_disabled())
ctx = audit_context();
ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
if (unlikely(!ab))
return;
audit_log_format(ab, "prog-id=%u op=%s",
prog->aux->id, bpf_audit_str[op]);
audit_log_end(ab);
}
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)
{
unsigned long flags;
/* 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;
spin_lock_irqsave(&prog_idr_lock, flags);
idr_remove(&prog_idr, prog->aux->id);
prog->aux->id = 0;
spin_unlock_irqrestore(&prog_idr_lock, flags);
}
static void __bpf_prog_put_rcu(struct rcu_head *rcu)
{
struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu);
kvfree(aux->func_info);
kfree(aux->func_info_aux);
free_uid(aux->user);
security_bpf_prog_free(aux->prog);
bpf_prog_free(aux->prog);
}
static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
{
bpf_prog_kallsyms_del_all(prog);
btf_put(prog->aux->btf);
module_put(prog->aux->mod);
kvfree(prog->aux->jited_linfo);
kvfree(prog->aux->linfo);
kfree(prog->aux->kfunc_tab);
if (prog->aux->attach_btf)
btf_put(prog->aux->attach_btf);
if (deferred) {
if (prog->sleepable)
call_rcu_tasks_trace(&prog->aux->rcu, __bpf_prog_put_rcu);
else
call_rcu(&prog->aux->rcu, __bpf_prog_put_rcu);
} else {
__bpf_prog_put_rcu(&prog->aux->rcu);
}
}
static void bpf_prog_put_deferred(struct work_struct *work)
{
struct bpf_prog_aux *aux;
struct bpf_prog *prog;
aux = container_of(work, struct bpf_prog_aux, work);
prog = aux->prog;
perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
bpf_prog_free_id(prog);
__bpf_prog_put_noref(prog, true);
}
static void __bpf_prog_put(struct bpf_prog *prog)
{
struct bpf_prog_aux *aux = prog->aux;
if (atomic64_dec_and_test(&aux->refcnt)) {
if (in_irq() || irqs_disabled()) {
INIT_WORK(&aux->work, bpf_prog_put_deferred);
schedule_work(&aux->work);
} else {
bpf_prog_put_deferred(&aux->work);
}
}
}
void bpf_prog_put(struct bpf_prog *prog)
{
__bpf_prog_put(prog);
}
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;
}
struct bpf_prog_kstats {
u64 nsecs;
u64 cnt;
u64 misses;
};
void notrace bpf_prog_inc_misses_counter(struct bpf_prog *prog)
{
struct bpf_prog_stats *stats;
unsigned int flags;
stats = this_cpu_ptr(prog->stats);
flags = u64_stats_update_begin_irqsave(&stats->syncp);
u64_stats_inc(&stats->misses);
u64_stats_update_end_irqrestore(&stats->syncp, flags);
}
static void bpf_prog_get_stats(const struct bpf_prog *prog,
struct bpf_prog_kstats *stats)
{
u64 nsecs = 0, cnt = 0, misses = 0;
int cpu;
for_each_possible_cpu(cpu) {
const struct bpf_prog_stats *st;
unsigned int start;
u64 tnsecs, tcnt, tmisses;
st = per_cpu_ptr(prog->stats, cpu);
do {
start = u64_stats_fetch_begin(&st->syncp);
tnsecs = u64_stats_read(&st->nsecs);
tcnt = u64_stats_read(&st->cnt);
tmisses = u64_stats_read(&st->misses);
} while (u64_stats_fetch_retry(&st->syncp, start));
nsecs += tnsecs;
cnt += tcnt;
misses += tmisses;
}
stats->nsecs = nsecs;
stats->cnt = cnt;
stats->misses = misses;
}
#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] = { };
struct bpf_prog_kstats stats;
bpf_prog_get_stats(prog, &stats);
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_id:\t%u\n"
"run_time_ns:\t%llu\n"
"run_cnt:\t%llu\n"
"recursion_misses:\t%llu\n"
"verified_insns:\t%u\n",
prog->type,
prog->jited,
prog_tag,
prog->pages * 1ULL << PAGE_SHIFT,
prog->aux->id,
stats.nsecs,
stats.cnt,
stats.misses,
prog->aux->verified_insns);
}
#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);
}
void bpf_prog_add(struct bpf_prog *prog, int i)
{
atomic64_add(i, &prog->aux->refcnt);
}
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(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
}
EXPORT_SYMBOL_GPL(bpf_prog_sub);
void bpf_prog_inc(struct bpf_prog *prog)
{
atomic64_inc(&prog->aux->refcnt);
}
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 = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
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_offloaded(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)
{
CLASS(fd, f)(ufd);
struct bpf_prog *prog;
if (fd_empty(f))
return ERR_PTR(-EBADF);
if (fd_file(f)->f_op != &bpf_prog_fops)
return ERR_PTR(-EINVAL);
prog = fd_file(f)->private_data;
if (!bpf_prog_get_ok(prog, attach_type, attach_drv))
return ERR_PTR(-EINVAL);
bpf_prog_inc(prog);
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)
{
return __bpf_prog_get(ufd, &type, attach_drv);
}
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;
case BPF_PROG_TYPE_SK_REUSEPORT:
if (!attr->expected_attach_type)
attr->expected_attach_type =
BPF_SK_REUSEPORT_SELECT;
break;
}
}
static int
bpf_prog_load_check_attach(enum bpf_prog_type prog_type,
enum bpf_attach_type expected_attach_type,
struct btf *attach_btf, u32 btf_id,
struct bpf_prog *dst_prog)
{
if (btf_id) {
if (btf_id > BTF_MAX_TYPE)
return -EINVAL;
if (!attach_btf && !dst_prog)
return -EINVAL;
switch (prog_type) {
case BPF_PROG_TYPE_TRACING:
case BPF_PROG_TYPE_LSM:
case BPF_PROG_TYPE_STRUCT_OPS:
case BPF_PROG_TYPE_EXT:
break;
default:
return -EINVAL;
}
}
if (attach_btf && (!btf_id || dst_prog))
return -EINVAL;
if (dst_prog && prog_type != BPF_PROG_TYPE_TRACING &&
prog_type != BPF_PROG_TYPE_EXT)
return -EINVAL;
switch (prog_type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
switch (expected_attach_type) {
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET_SOCK_RELEASE:
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:
case BPF_CGROUP_UNIX_CONNECT:
case BPF_CGROUP_INET4_GETPEERNAME:
case BPF_CGROUP_INET6_GETPEERNAME:
case BPF_CGROUP_UNIX_GETPEERNAME:
case BPF_CGROUP_INET4_GETSOCKNAME:
case BPF_CGROUP_INET6_GETSOCKNAME:
case BPF_CGROUP_UNIX_GETSOCKNAME:
case BPF_CGROUP_UDP4_SENDMSG:
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UNIX_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
case BPF_CGROUP_UNIX_RECVMSG:
return 0;
default:
return -EINVAL;
}
case BPF_PROG_TYPE_CGROUP_SKB:
switch (expected_attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
return 0;
default:
return -EINVAL;
}
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
switch (expected_attach_type) {
case BPF_CGROUP_SETSOCKOPT:
case BPF_CGROUP_GETSOCKOPT:
return 0;
default:
return -EINVAL;
}
case BPF_PROG_TYPE_SK_LOOKUP:
if (expected_attach_type == BPF_SK_LOOKUP)
return 0;
return -EINVAL;
case BPF_PROG_TYPE_SK_REUSEPORT:
switch (expected_attach_type) {
case BPF_SK_REUSEPORT_SELECT:
case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE:
return 0;
default:
return -EINVAL;
}
case BPF_PROG_TYPE_NETFILTER:
if (expected_attach_type == BPF_NETFILTER)
return 0;
return -EINVAL;
case BPF_PROG_TYPE_SYSCALL:
case BPF_PROG_TYPE_EXT:
if (expected_attach_type)
return -EINVAL;
fallthrough;
default:
return 0;
}
}
static bool is_net_admin_prog_type(enum bpf_prog_type prog_type)
{
switch (prog_type) {
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
case BPF_PROG_TYPE_XDP:
case BPF_PROG_TYPE_LWT_IN:
case BPF_PROG_TYPE_LWT_OUT:
case BPF_PROG_TYPE_LWT_XMIT:
case BPF_PROG_TYPE_LWT_SEG6LOCAL:
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_FLOW_DISSECTOR:
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_EXT: /* extends any prog */
case BPF_PROG_TYPE_NETFILTER:
return true;
case BPF_PROG_TYPE_CGROUP_SKB:
/* always unpriv */
case BPF_PROG_TYPE_SK_REUSEPORT:
/* equivalent to SOCKET_FILTER. need CAP_BPF only */
default:
return false;
}
}
static bool is_perfmon_prog_type(enum bpf_prog_type prog_type)
{
switch (prog_type) {
case BPF_PROG_TYPE_KPROBE:
case BPF_PROG_TYPE_TRACEPOINT:
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_RAW_TRACEPOINT:
case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
case BPF_PROG_TYPE_TRACING:
case BPF_PROG_TYPE_LSM:
case BPF_PROG_TYPE_STRUCT_OPS: /* has access to struct sock */
case BPF_PROG_TYPE_EXT: /* extends any prog */
return true;
default:
return false;
}
}
/* last field in 'union bpf_attr' used by this command */
#define BPF_PROG_LOAD_LAST_FIELD prog_token_fd
static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
{
enum bpf_prog_type type = attr->prog_type;
struct bpf_prog *prog, *dst_prog = NULL;
struct btf *attach_btf = NULL;
struct bpf_token *token = NULL;
bool bpf_cap;
int err;
char license[128];
if (CHECK_ATTR(BPF_PROG_LOAD))
return -EINVAL;
if (attr->prog_flags & ~(BPF_F_STRICT_ALIGNMENT |
BPF_F_ANY_ALIGNMENT |
BPF_F_TEST_STATE_FREQ |
BPF_F_SLEEPABLE |
BPF_F_TEST_RND_HI32 |
BPF_F_XDP_HAS_FRAGS |
BPF_F_XDP_DEV_BOUND_ONLY |
BPF_F_TEST_REG_INVARIANTS |
BPF_F_TOKEN_FD))
return -EINVAL;
bpf_prog_load_fixup_attach_type(attr);
if (attr->prog_flags & BPF_F_TOKEN_FD) {
token = bpf_token_get_from_fd(attr->prog_token_fd);
if (IS_ERR(token))
return PTR_ERR(token);
/* if current token doesn't grant prog loading permissions,
* then we can't use this token, so ignore it and rely on
* system-wide capabilities checks
*/
if (!bpf_token_allow_cmd(token, BPF_PROG_LOAD) ||
!bpf_token_allow_prog_type(token, attr->prog_type,
attr->expected_attach_type)) {
bpf_token_put(token);
token = NULL;
}
}
bpf_cap = bpf_token_capable(token, CAP_BPF);
err = -EPERM;
if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) &&
(attr->prog_flags & BPF_F_ANY_ALIGNMENT) &&
!bpf_cap)
goto put_token;
/* Intent here is for unprivileged_bpf_disabled to block BPF program
* creation for unprivileged users; other actions depend
* on fd availability and access to bpffs, so are dependent on
* object creation success. Even with unprivileged BPF disabled,
* capability checks are still carried out for these
* and other operations.
*/
if (sysctl_unprivileged_bpf_disabled && !bpf_cap)
goto put_token;
if (attr->insn_cnt == 0 ||
attr->insn_cnt > (bpf_cap ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS)) {
err = -E2BIG;
goto put_token;
}
if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
type != BPF_PROG_TYPE_CGROUP_SKB &&
!bpf_cap)
goto put_token;
if (is_net_admin_prog_type(type) && !bpf_token_capable(token, CAP_NET_ADMIN))
goto put_token;
if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
goto put_token;
/* attach_prog_fd/attach_btf_obj_fd can specify fd of either bpf_prog
* or btf, we need to check which one it is
*/
if (attr->attach_prog_fd) {
dst_prog = bpf_prog_get(attr->attach_prog_fd);
if (IS_ERR(dst_prog)) {
dst_prog = NULL;
attach_btf = btf_get_by_fd(attr->attach_btf_obj_fd);
if (IS_ERR(attach_btf)) {
err = -EINVAL;
goto put_token;
}
if (!btf_is_kernel(attach_btf)) {
/* attaching through specifying bpf_prog's BTF
* objects directly might be supported eventually
*/
btf_put(attach_btf);
err = -ENOTSUPP;
goto put_token;
}
}
} else if (attr->attach_btf_id) {
/* fall back to vmlinux BTF, if BTF type ID is specified */
attach_btf = bpf_get_btf_vmlinux();
if (IS_ERR(attach_btf)) {
err = PTR_ERR(attach_btf);
goto put_token;
}
if (!attach_btf) {
err = -EINVAL;
goto put_token;
}
btf_get(attach_btf);
}
if (bpf_prog_load_check_attach(type, attr->expected_attach_type,
attach_btf, attr->attach_btf_id,
dst_prog)) {
if (dst_prog)
bpf_prog_put(dst_prog);
if (attach_btf)
btf_put(attach_btf);
err = -EINVAL;
goto put_token;
}
/* plain bpf_prog allocation */
prog = bpf_prog_alloc(bpf_prog_size(attr->insn_cnt), GFP_USER);
if (!prog) {
if (dst_prog)
bpf_prog_put(dst_prog);
if (attach_btf)
btf_put(attach_btf);
err = -EINVAL;
goto put_token;
}
prog->expected_attach_type = attr->expected_attach_type;
prog->sleepable = !!(attr->prog_flags & BPF_F_SLEEPABLE);
prog->aux->attach_btf = attach_btf;
prog->aux->attach_btf_id = attr->attach_btf_id;
prog->aux->dst_prog = dst_prog;
prog->aux->dev_bound = !!attr->prog_ifindex;
prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS;
/* move token into prog->aux, reuse taken refcnt */
prog->aux->token = token;
token = NULL;
prog->aux->user = get_current_user();
prog->len = attr->insn_cnt;
err = -EFAULT;
if (copy_from_bpfptr(prog->insns,
make_bpfptr(attr->insns, uattr.is_kernel),
bpf_prog_insn_size(prog)) != 0)
goto free_prog;
/* copy eBPF program license from user space */
if (strncpy_from_bpfptr(license,
make_bpfptr(attr->license, uattr.is_kernel),
sizeof(license) - 1) < 0)
goto free_prog;
license[sizeof(license) - 1] = 0;
/* eBPF programs must be GPL compatible to use GPL-ed functions */
prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
prog->orig_prog = NULL;
prog->jited = 0;
atomic64_set(&prog->aux->refcnt, 1);
if (bpf_prog_is_dev_bound(prog->aux)) {
err = bpf_prog_dev_bound_init(prog, attr);
if (err)
goto free_prog;
}
if (type == BPF_PROG_TYPE_EXT && dst_prog &&
bpf_prog_is_dev_bound(dst_prog->aux)) {
err = bpf_prog_dev_bound_inherit(prog, dst_prog);
if (err)
goto free_prog;
}
/*
* Bookkeeping for managing the program attachment chain.
*
* It might be tempting to set attach_tracing_prog flag at the attachment
* time, but this will not prevent from loading bunch of tracing prog
* first, then attach them one to another.
*
* The flag attach_tracing_prog is set for the whole program lifecycle, and
* doesn't have to be cleared in bpf_tracing_link_release, since tracing
* programs cannot change attachment target.
*/
if (type == BPF_PROG_TYPE_TRACING && dst_prog &&
dst_prog->type == BPF_PROG_TYPE_TRACING) {
prog->aux->attach_tracing_prog = true;
}
/* 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_boottime_ns();
err = bpf_obj_name_cpy(prog->aux->name, attr->prog_name,
sizeof(attr->prog_name));
if (err < 0)
goto free_prog;
err = security_bpf_prog_load(prog, attr, token);
if (err)
goto free_prog_sec;
/* run eBPF verifier */
err = bpf_check(&prog, attr, uattr, uattr_size);
if (err < 0)
goto free_used_maps;
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;
/* Upon success of bpf_prog_alloc_id(), the BPF prog is
* effectively publicly exposed. However, retrieving via
* bpf_prog_get_fd_by_id() will take another reference,
* therefore it cannot be gone underneath us.
*
* Only for the time /after/ successful bpf_prog_new_fd()
* and before returning to userspace, we might just hold
* one reference and any parallel close on that fd could
* rip everything out. Hence, below notifications must
* happen before bpf_prog_new_fd().
*
* Also, any failure handling from this point onwards must
* be using bpf_prog_put() given the program is exposed.
*/
bpf_prog_kallsyms_add(prog);
perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
bpf_audit_prog(prog, BPF_AUDIT_LOAD);
err = bpf_prog_new_fd(prog);
if (err < 0)
bpf_prog_put(prog);
return err;
free_used_maps:
/* In case we have subprogs, we need to wait for a grace
* period before we can tear down JIT memory since symbols
* are already exposed under kallsyms.
*/
__bpf_prog_put_noref(prog, prog->aux->real_func_cnt);
return err;
free_prog_sec:
security_bpf_prog_free(prog);
free_prog:
free_uid(prog->aux->user);
if (prog->aux->attach_btf)
btf_put(prog->aux->attach_btf);
bpf_prog_free(prog);
put_token:
bpf_token_put(token);
return err;
}
#define BPF_OBJ_LAST_FIELD path_fd
static int bpf_obj_pin(const union bpf_attr *attr)
{
int path_fd;
if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
return -EINVAL;
/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
return -EINVAL;
path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
return bpf_obj_pin_user(attr->bpf_fd, path_fd,
u64_to_user_ptr(attr->pathname));
}
static int bpf_obj_get(const union bpf_attr *attr)
{
int path_fd;
if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
return -EINVAL;
/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
return -EINVAL;
path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
attr->file_flags);
}
void bpf_link_init(struct bpf_link *link, enum bpf_link_type type,
const struct bpf_link_ops *ops, struct bpf_prog *prog)
{
WARN_ON(ops->dealloc && ops->dealloc_deferred);
atomic64_set(&link->refcnt, 1);
link->type = type;
link->id = 0;
link->ops = ops;
link->prog = prog;
}
static void bpf_link_free_id(int id)
{
if (!id)
return;
spin_lock_bh(&link_idr_lock);
idr_remove(&link_idr, id);
spin_unlock_bh(&link_idr_lock);
}
/* Clean up bpf_link and corresponding anon_inode file and FD. After
* anon_inode is created, bpf_link can't be just kfree()'d due to deferred
* anon_inode's release() call. This helper marks bpf_link as
* defunct, releases anon_inode file and puts reserved FD. bpf_prog's refcnt
* is not decremented, it's the responsibility of a calling code that failed
* to complete bpf_link initialization.
* This helper eventually calls link's dealloc callback, but does not call
* link's release callback.
*/
void bpf_link_cleanup(struct bpf_link_primer *primer)
{
primer->link->prog = NULL;
bpf_link_free_id(primer->id);
fput(primer->file);
put_unused_fd(primer->fd);
}
void bpf_link_inc(struct bpf_link *link)
{
atomic64_inc(&link->refcnt);
}
static void bpf_link_defer_dealloc_rcu_gp(struct rcu_head *rcu)
{
struct bpf_link *link = container_of(rcu, struct bpf_link, rcu);
/* free bpf_link and its containing memory */
link->ops->dealloc_deferred(link);
}
static void bpf_link_defer_dealloc_mult_rcu_gp(struct rcu_head *rcu)
{
if (rcu_trace_implies_rcu_gp())
bpf_link_defer_dealloc_rcu_gp(rcu);
else
call_rcu(rcu, bpf_link_defer_dealloc_rcu_gp);
}
/* bpf_link_free is guaranteed to be called from process context */
static void bpf_link_free(struct bpf_link *link)
{
const struct bpf_link_ops *ops = link->ops;
bool sleepable = false;
bpf_link_free_id(link->id);
if (link->prog) {
sleepable = link->prog->sleepable;
/* detach BPF program, clean up used resources */
ops->release(link);
bpf_prog_put(link->prog);
}
if (ops->dealloc_deferred) {
/* schedule BPF link deallocation; if underlying BPF program
* is sleepable, we need to first wait for RCU tasks trace
* sync, then go through "classic" RCU grace period
*/
if (sleepable)
call_rcu_tasks_trace(&link->rcu, bpf_link_defer_dealloc_mult_rcu_gp);
else
call_rcu(&link->rcu, bpf_link_defer_dealloc_rcu_gp);
} else if (ops->dealloc)
ops->dealloc(link);
}
static void bpf_link_put_deferred(struct work_struct *work)
{
struct bpf_link *link = container_of(work, struct bpf_link, work);
bpf_link_free(link);
}
/* bpf_link_put might be called from atomic context. It needs to be called
* from sleepable context in order to acquire sleeping locks during the process.
*/
void bpf_link_put(struct bpf_link *link)
{
if (!atomic64_dec_and_test(&link->refcnt))
return;
INIT_WORK(&link->work, bpf_link_put_deferred);
schedule_work(&link->work);
}
EXPORT_SYMBOL(bpf_link_put);
static void bpf_link_put_direct(struct bpf_link *link)
{
if (!atomic64_dec_and_test(&link->refcnt))
return;
bpf_link_free(link);
}
static int bpf_link_release(struct inode *inode, struct file *filp)
{
struct bpf_link *link = filp->private_data;
bpf_link_put_direct(link);
return 0;
}
#ifdef CONFIG_PROC_FS
#define BPF_PROG_TYPE(_id, _name, prog_ctx_type, kern_ctx_type)
#define BPF_MAP_TYPE(_id, _ops)
#define BPF_LINK_TYPE(_id, _name) [_id] = #_name,
static const char *bpf_link_type_strs[] = {
[BPF_LINK_TYPE_UNSPEC] = "<invalid>",
#include <linux/bpf_types.h>
};
#undef BPF_PROG_TYPE
#undef BPF_MAP_TYPE
#undef BPF_LINK_TYPE
static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
{
const struct bpf_link *link = filp->private_data;
const struct bpf_prog *prog = link->prog;
enum bpf_link_type type = link->type;
char prog_tag[sizeof(prog->tag) * 2 + 1] = { };
if (type < ARRAY_SIZE(bpf_link_type_strs) && bpf_link_type_strs[type]) {
seq_printf(m, "link_type:\t%s\n", bpf_link_type_strs[type]);
} else {
WARN_ONCE(1, "missing BPF_LINK_TYPE(...) for link type %u\n", type);
seq_printf(m, "link_type:\t<%u>\n", type);
}
seq_printf(m, "link_id:\t%u\n", link->id);
if (prog) {
bin2hex(prog_tag, prog->tag, sizeof(prog->tag));
seq_printf(m,
"prog_tag:\t%s\n"
"prog_id:\t%u\n",
prog_tag,
prog->aux->id);
}
if (link->ops->show_fdinfo)
link->ops->show_fdinfo(link, m);
}
#endif
static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
{
struct bpf_link *link = file->private_data;
return link->ops->poll(file, pts);
}
static const struct file_operations bpf_link_fops = {
#ifdef CONFIG_PROC_FS
.show_fdinfo = bpf_link_show_fdinfo,
#endif
.release = bpf_link_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
};
static const struct file_operations bpf_link_fops_poll = {
#ifdef CONFIG_PROC_FS
.show_fdinfo = bpf_link_show_fdinfo,
#endif
.release = bpf_link_release,
.read = bpf_dummy_read,
.write = bpf_dummy_write,
.poll = bpf_link_poll,
};
static int bpf_link_alloc_id(struct bpf_link *link)
{
int id;
idr_preload(GFP_KERNEL);
spin_lock_bh(&link_idr_lock);
id = idr_alloc_cyclic(&link_idr, link, 1, INT_MAX, GFP_ATOMIC);
spin_unlock_bh(&link_idr_lock);
idr_preload_end();
return id;
}
/* Prepare bpf_link to be exposed to user-space by allocating anon_inode file,
* reserving unused FD and allocating ID from link_idr. This is to be paired
* with bpf_link_settle() to install FD and ID and expose bpf_link to
* user-space, if bpf_link is successfully attached. If not, bpf_link and
* pre-allocated resources are to be freed with bpf_cleanup() call. All the
* transient state is passed around in struct bpf_link_primer.
* This is preferred way to create and initialize bpf_link, especially when
* there are complicated and expensive operations in between creating bpf_link
* itself and attaching it to BPF hook. By using bpf_link_prime() and
* bpf_link_settle() kernel code using bpf_link doesn't have to perform
* expensive (and potentially failing) roll back operations in a rare case
* that file, FD, or ID can't be allocated.
*/
int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
{
struct file *file;
int fd, id;
fd = get_unused_fd_flags(O_CLOEXEC);
if (fd < 0)
return fd;
id = bpf_link_alloc_id(link);
if (id < 0) {
put_unused_fd(fd);
return id;
}
file = anon_inode_getfile("bpf_link",
link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
link, O_CLOEXEC);
if (IS_ERR(file)) {
bpf_link_free_id(id);
put_unused_fd(fd);
return PTR_ERR(file);
}
primer->link = link;
primer->file = file;
primer->fd = fd;
primer->id = id;
return 0;
}
int bpf_link_settle(struct bpf_link_primer *primer)
{
/* make bpf_link fetchable by ID */
spin_lock_bh(&link_idr_lock);
primer->link->id = primer->id;
spin_unlock_bh(&link_idr_lock);
/* make bpf_link fetchable by FD */
fd_install(primer->fd, primer->file);
/* pass through installed FD */
return primer->fd;
}
int bpf_link_new_fd(struct bpf_link *link)
{
return anon_inode_getfd("bpf-link",
link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
link, O_CLOEXEC);
}
struct bpf_link *bpf_link_get_from_fd(u32 ufd)
{
CLASS(fd, f)(ufd);
struct bpf_link *link;
if (fd_empty(f))
return ERR_PTR(-EBADF);
if (fd_file(f)->f_op != &bpf_link_fops && fd_file(f)->f_op != &bpf_link_fops_poll)
return ERR_PTR(-EINVAL);
link = fd_file(f)->private_data;
bpf_link_inc(link);
return link;
}
EXPORT_SYMBOL(bpf_link_get_from_fd);
static void bpf_tracing_link_release(struct bpf_link *link)
{
struct bpf_tracing_link *tr_link =
container_of(link, struct bpf_tracing_link, link.link);
WARN_ON_ONCE(bpf_trampoline_unlink_prog(&tr_link->link,
tr_link->trampoline));
bpf_trampoline_put(tr_link->trampoline);
/* tgt_prog is NULL if target is a kernel function */
if (tr_link->tgt_prog)
bpf_prog_put(tr_link->tgt_prog);
}
static void bpf_tracing_link_dealloc(struct bpf_link *link)
{
struct bpf_tracing_link *tr_link =
container_of(link, struct bpf_tracing_link, link.link);
kfree(tr_link);
}
static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
struct seq_file *seq)
{
struct bpf_tracing_link *tr_link =
container_of(link, struct bpf_tracing_link, link.link);
u32 target_btf_id, target_obj_id;
bpf_trampoline_unpack_key(tr_link->trampoline->key,
&target_obj_id, &target_btf_id);
seq_printf(seq,
"attach_type:\t%d\n"
"target_obj_id:\t%u\n"
"target_btf_id:\t%u\n",
tr_link->attach_type,
target_obj_id,
target_btf_id);
}
static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
struct bpf_link_info *info)
{
struct bpf_tracing_link *tr_link =
container_of(link, struct bpf_tracing_link, link.link);
info->tracing.attach_type = tr_link->attach_type;
bpf_trampoline_unpack_key(tr_link->trampoline->key,
&info->tracing.target_obj_id,
&info->tracing.target_btf_id);
return 0;
}
static const struct bpf_link_ops bpf_tracing_link_lops = {
.release = bpf_tracing_link_release,
.dealloc = bpf_tracing_link_dealloc,
.show_fdinfo = bpf_tracing_link_show_fdinfo,
.fill_link_info = bpf_tracing_link_fill_link_info,
};
static int bpf_tracing_prog_attach(struct bpf_prog *prog,
int tgt_prog_fd,
u32 btf_id,
u64 bpf_cookie)
{
struct bpf_link_primer link_primer;
struct bpf_prog *tgt_prog = NULL;
struct bpf_trampoline *tr = NULL;
struct bpf_tracing_link *link;
u64 key = 0;
int err;
switch (prog->type) {
case BPF_PROG_TYPE_TRACING:
if (prog->expected_attach_type != BPF_TRACE_FENTRY &&
prog->expected_attach_type != BPF_TRACE_FEXIT &&
prog->expected_attach_type != BPF_MODIFY_RETURN) {
err = -EINVAL;
goto out_put_prog;
}
break;
case BPF_PROG_TYPE_EXT:
if (prog->expected_attach_type != 0) {
err = -EINVAL;
goto out_put_prog;
}
break;
case BPF_PROG_TYPE_LSM:
if (prog->expected_attach_type != BPF_LSM_MAC) {
err = -EINVAL;
goto out_put_prog;
}
break;
default:
err = -EINVAL;
goto out_put_prog;
}
if (!!tgt_prog_fd != !!btf_id) {
err = -EINVAL;
goto out_put_prog;
}
if (tgt_prog_fd) {
/*
* For now we only allow new targets for BPF_PROG_TYPE_EXT. If this
* part would be changed to implement the same for
* BPF_PROG_TYPE_TRACING, do not forget to update the way how
* attach_tracing_prog flag is set.
*/
if (prog->type != BPF_PROG_TYPE_EXT) {
err = -EINVAL;
goto out_put_prog;
}
tgt_prog = bpf_prog_get(tgt_prog_fd);
if (IS_ERR(tgt_prog)) {
err = PTR_ERR(tgt_prog);
tgt_prog = NULL;
goto out_put_prog;
}
key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id);
}
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto out_put_prog;
}
bpf_link_init(&link->link.link, BPF_LINK_TYPE_TRACING,
&bpf_tracing_link_lops, prog);
link->attach_type = prog->expected_attach_type;
link->link.cookie = bpf_cookie;
mutex_lock(&prog->aux->dst_mutex);
/* There are a few possible cases here:
*
* - if prog->aux->dst_trampoline is set, the program was just loaded
* and not yet attached to anything, so we can use the values stored
* in prog->aux
*
* - if prog->aux->dst_trampoline is NULL, the program has already been
* attached to a target and its initial target was cleared (below)
*
* - if tgt_prog != NULL, the caller specified tgt_prog_fd +
* target_btf_id using the link_create API.
*
* - if tgt_prog == NULL when this function was called using the old
* raw_tracepoint_open API, and we need a target from prog->aux
*
* - if prog->aux->dst_trampoline and tgt_prog is NULL, the program
* was detached and is going for re-attachment.
*
* - if prog->aux->dst_trampoline is NULL and tgt_prog and prog->aux->attach_btf
* are NULL, then program was already attached and user did not provide
* tgt_prog_fd so we have no way to find out or create trampoline
*/
if (!prog->aux->dst_trampoline && !tgt_prog) {
/*
* Allow re-attach for TRACING and LSM programs. If it's
* currently linked, bpf_trampoline_link_prog will fail.
* EXT programs need to specify tgt_prog_fd, so they
* re-attach in separate code path.
*/
if (prog->type != BPF_PROG_TYPE_TRACING &&
prog->type != BPF_PROG_TYPE_LSM) {
err = -EINVAL;
goto out_unlock;
}
/* We can allow re-attach only if we have valid attach_btf. */
if (!prog->aux->attach_btf) {
err = -EINVAL;
goto out_unlock;
}
btf_id = prog->aux->attach_btf_id;
key = bpf_trampoline_compute_key(NULL, prog->aux->attach_btf, btf_id);
}
if (!prog->aux->dst_trampoline ||
(key && key != prog->aux->dst_trampoline->key)) {
/* If there is no saved target, or the specified target is
* different from the destination specified at load time, we
* need a new trampoline and a check for compatibility
*/
struct bpf_attach_target_info tgt_info = {};
err = bpf_check_attach_target(NULL, prog, tgt_prog, btf_id,
&tgt_info);
if (err)
goto out_unlock;
if (tgt_info.tgt_mod) {
module_put(prog->aux->mod);
prog->aux->mod = tgt_info.tgt_mod;
}
tr = bpf_trampoline_get(key, &tgt_info);
if (!tr) {
err = -ENOMEM;
goto out_unlock;
}
} else {
/* The caller didn't specify a target, or the target was the
* same as the destination supplied during program load. This
* means we can reuse the trampoline and reference from program
* load time, and there is no need to allocate a new one. This
* can only happen once for any program, as the saved values in
* prog->aux are cleared below.
*/
tr = prog->aux->dst_trampoline;
tgt_prog = prog->aux->dst_prog;
}
err = bpf_link_prime(&link->link.link, &link_primer);
if (err)
goto out_unlock;
err = bpf_trampoline_link_prog(&link->link, tr);
if (err) {
bpf_link_cleanup(&link_primer);
link = NULL;
goto out_unlock;
}
link->tgt_prog = tgt_prog;
link->trampoline = tr;
/* Always clear the trampoline and target prog from prog->aux to make
* sure the original attach destination is not kept alive after a
* program is (re-)attached to another target.
*/
if (prog->aux->dst_prog &&
(tgt_prog_fd || tr != prog->aux->dst_trampoline))
/* got extra prog ref from syscall, or attaching to different prog */
bpf_prog_put(prog->aux->dst_prog);
if (prog->aux->dst_trampoline && tr != prog->aux->dst_trampoline)
/* we allocated a new trampoline, so free the old one */
bpf_trampoline_put(prog->aux->dst_trampoline);
prog->aux->dst_prog = NULL;
prog->aux->dst_trampoline = NULL;
mutex_unlock(&prog->aux->dst_mutex);
return bpf_link_settle(&link_primer);
out_unlock:
if (tr && tr != prog->aux->dst_trampoline)
bpf_trampoline_put(tr);
mutex_unlock(&prog->aux->dst_mutex);
kfree(link);
out_put_prog:
if (tgt_prog_fd && tgt_prog)
bpf_prog_put(tgt_prog);
return err;
}
static void bpf_raw_tp_link_release(struct bpf_link *link)
{
struct bpf_raw_tp_link *raw_tp =
container_of(link, struct bpf_raw_tp_link, link);
bpf_probe_unregister(raw_tp->btp, raw_tp);
bpf_put_raw_tracepoint(raw_tp->btp);
}
static void bpf_raw_tp_link_dealloc(struct bpf_link *link)
{
struct bpf_raw_tp_link *raw_tp =
container_of(link, struct bpf_raw_tp_link, link);
kfree(raw_tp);
}
static void bpf_raw_tp_link_show_fdinfo(const struct bpf_link *link,
struct seq_file *seq)
{
struct bpf_raw_tp_link *raw_tp_link =
container_of(link, struct bpf_raw_tp_link, link);
seq_printf(seq,
"tp_name:\t%s\n",
raw_tp_link->btp->tp->name);
}
static int bpf_copy_to_user(char __user *ubuf, const char *buf, u32 ulen,
u32 len)
{
if (ulen >= len + 1) {
if (copy_to_user(ubuf, buf, len + 1))
return -EFAULT;
} else {
char zero = '\0';
if (copy_to_user(ubuf, buf, ulen - 1))
return -EFAULT;
if (put_user(zero, ubuf + ulen - 1))
return -EFAULT;
return -ENOSPC;
}
return 0;
}
static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
struct bpf_link_info *info)
{
struct bpf_raw_tp_link *raw_tp_link =
container_of(link, struct bpf_raw_tp_link, link);
char __user *ubuf = u64_to_user_ptr(info->raw_tracepoint.tp_name);
const char *tp_name = raw_tp_link->btp->tp->name;
u32 ulen = info->raw_tracepoint.tp_name_len;
size_t tp_len = strlen(tp_name);
if (!ulen ^ !ubuf)
return -EINVAL;
info->raw_tracepoint.tp_name_len = tp_len + 1;
if (!ubuf)
return 0;
return bpf_copy_to_user(ubuf, tp_name, ulen, tp_len);
}
static const struct bpf_link_ops bpf_raw_tp_link_lops = {
.release = bpf_raw_tp_link_release,
.dealloc_deferred = bpf_raw_tp_link_dealloc,
.show_fdinfo = bpf_raw_tp_link_show_fdinfo,
.fill_link_info = bpf_raw_tp_link_fill_link_info,
};
#ifdef CONFIG_PERF_EVENTS
struct bpf_perf_link {
struct bpf_link link;
struct file *perf_file;
};
static void bpf_perf_link_release(struct bpf_link *link)
{
struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
struct perf_event *event = perf_link->perf_file->private_data;
perf_event_free_bpf_prog(event);
fput(perf_link->perf_file);
}
static void bpf_perf_link_dealloc(struct bpf_link *link)
{
struct bpf_perf_link *perf_link = container_of(link, struct bpf_perf_link, link);
kfree(perf_link);
}
static int bpf_perf_link_fill_common(const struct perf_event *event,
char __user *uname, u32 *ulenp,
u64 *probe_offset, u64 *probe_addr,
u32 *fd_type, unsigned long *missed)
{
const char *buf;
u32 prog_id, ulen;
size_t len;
int err;
ulen = *ulenp;
if (!ulen ^ !uname)
return -EINVAL;
err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
probe_offset, probe_addr, missed);
if (err)
return err;
if (buf) {
len = strlen(buf);
*ulenp = len + 1;
} else {
*ulenp = 1;
}
if (!uname)
return 0;
if (buf) {
err = bpf_copy_to_user(uname, buf, ulen, len);
if (err)
return err;
} else {
char zero = '\0';
if (put_user(zero, uname))
return -EFAULT;
}
return 0;
}
#ifdef CONFIG_KPROBE_EVENTS
static int bpf_perf_link_fill_kprobe(const struct perf_event *event,
struct bpf_link_info *info)
{
unsigned long missed;
char __user *uname;
u64 addr, offset;
u32 ulen, type;
int err;
uname = u64_to_user_ptr(info->perf_event.kprobe.func_name);
ulen = info->perf_event.kprobe.name_len;
err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
&type, &missed);
if (err)
return err;
if (type == BPF_FD_TYPE_KRETPROBE)
info->perf_event.type = BPF_PERF_EVENT_KRETPROBE;
else
info->perf_event.type = BPF_PERF_EVENT_KPROBE;
info->perf_event.kprobe.name_len = ulen;
info->perf_event.kprobe.offset = offset;
info->perf_event.kprobe.missed = missed;
if (!kallsyms_show_value(current_cred()))
addr = 0;
info->perf_event.kprobe.addr = addr;
info->perf_event.kprobe.cookie = event->bpf_cookie;
return 0;
}
#endif
#ifdef CONFIG_UPROBE_EVENTS
static int bpf_perf_link_fill_uprobe(const struct perf_event *event,
struct bpf_link_info *info)
{
char __user *uname;
u64 addr, offset;
u32 ulen, type;
int err;
uname = u64_to_user_ptr(info->perf_event.uprobe.file_name);
ulen = info->perf_event.uprobe.name_len;
err = bpf_perf_link_fill_common(event, uname, &ulen, &offset, &addr,
&type, NULL);
if (err)
return err;
if (type == BPF_FD_TYPE_URETPROBE)
info->perf_event.type = BPF_PERF_EVENT_URETPROBE;
else
info->perf_event.type = BPF_PERF_EVENT_UPROBE;
info->perf_event.uprobe.name_len = ulen;
info->perf_event.uprobe.offset = offset;
info->perf_event.uprobe.cookie = event->bpf_cookie;
return 0;
}
#endif
static int bpf_perf_link_fill_probe(const struct perf_event *event,
struct bpf_link_info *info)
{
#ifdef CONFIG_KPROBE_EVENTS
if (event->tp_event->flags & TRACE_EVENT_FL_KPROBE)
return bpf_perf_link_fill_kprobe(event, info);
#endif
#ifdef CONFIG_UPROBE_EVENTS
if (event->tp_event->flags & TRACE_EVENT_FL_UPROBE)
return bpf_perf_link_fill_uprobe(event, info);
#endif
return -EOPNOTSUPP;
}
static int bpf_perf_link_fill_tracepoint(const struct perf_event *event,
struct bpf_link_info *info)
{
char __user *uname;
u32 ulen;
int err;
uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name);
ulen = info->perf_event.tracepoint.name_len;
err = bpf_perf_link_fill_common(event, uname, &ulen, NULL, NULL, NULL, NULL);
if (err)
return err;
info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT;
info->perf_event.tracepoint.name_len = ulen;
info->perf_event.tracepoint.cookie = event->bpf_cookie;
return 0;
}
static int bpf_perf_link_fill_perf_event(const struct perf_event *event,
struct bpf_link_info *info)
{
info->perf_event.event.type = event->attr.type;
info->perf_event.event.config = event->attr.config;
info->perf_event.event.cookie = event->bpf_cookie;
info->perf_event.type = BPF_PERF_EVENT_EVENT;
return 0;
}
static int bpf_perf_link_fill_link_info(const struct bpf_link *link,
struct bpf_link_info *info)
{
struct bpf_perf_link *perf_link;
const struct perf_event *event;
perf_link = container_of(link, struct bpf_perf_link, link);
event = perf_get_event(perf_link->perf_file);
if (IS_ERR(event))
return PTR_ERR(event);
switch (event->prog->type) {
case BPF_PROG_TYPE_PERF_EVENT:
return bpf_perf_link_fill_perf_event(event, info);
case BPF_PROG_TYPE_TRACEPOINT:
return bpf_perf_link_fill_tracepoint(event, info);
case BPF_PROG_TYPE_KPROBE:
return bpf_perf_link_fill_probe(event, info);
default:
return -EOPNOTSUPP;
}
}
static const struct bpf_link_ops bpf_perf_link_lops = {
.release = bpf_perf_link_release,
.dealloc = bpf_perf_link_dealloc,
.fill_link_info = bpf_perf_link_fill_link_info,
};
static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
struct bpf_link_primer link_primer;
struct bpf_perf_link *link;
struct perf_event *event;
struct file *perf_file;
int err;
if (attr->link_create.flags)
return -EINVAL;
perf_file = perf_event_get(attr->link_create.target_fd);
if (IS_ERR(perf_file))
return PTR_ERR(perf_file);
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto out_put_file;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_PERF_EVENT, &bpf_perf_link_lops, prog);
link->perf_file = perf_file;
err = bpf_link_prime(&link->link, &link_primer);
if (err) {
kfree(link);
goto out_put_file;
}
event = perf_file->private_data;
err = perf_event_set_bpf_prog(event, prog, attr->link_create.perf_event.bpf_cookie);
if (err) {
bpf_link_cleanup(&link_primer);
goto out_put_file;
}
/* perf_event_set_bpf_prog() doesn't take its own refcnt on prog */
bpf_prog_inc(prog);
return bpf_link_settle(&link_primer);
out_put_file:
fput(perf_file);
return err;
}
#else
static int bpf_perf_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
{
return -EOPNOTSUPP;
}
#endif /* CONFIG_PERF_EVENTS */
static int bpf_raw_tp_link_attach(struct bpf_prog *prog,
const char __user *user_tp_name, u64 cookie)
{
struct bpf_link_primer link_primer;
struct bpf_raw_tp_link *link;
struct bpf_raw_event_map *btp;
const char *tp_name;
char buf[128];
int err;
switch (prog->type) {
case BPF_PROG_TYPE_TRACING:
case BPF_PROG_TYPE_EXT:
case BPF_PROG_TYPE_LSM:
if (user_tp_name)
/* The attach point for this category of programs
* should be specified via btf_id during program load.
*/
return -EINVAL;
if (prog->type == BPF_PROG_TYPE_TRACING &&
prog->expected_attach_type == BPF_TRACE_RAW_TP) {
tp_name = prog->aux->attach_func_name;
break;
}
return bpf_tracing_prog_attach(prog, 0, 0, 0);
case BPF_PROG_TYPE_RAW_TRACEPOINT:
case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
if (strncpy_from_user(buf, user_tp_name, sizeof(buf) - 1) < 0)
return -EFAULT;
buf[sizeof(buf) - 1] = 0;
tp_name = buf;
break;
default:
return -EINVAL;
}
btp = bpf_get_raw_tracepoint(tp_name);
if (!btp)
return -ENOENT;
link = kzalloc(sizeof(*link), GFP_USER);
if (!link) {
err = -ENOMEM;
goto out_put_btp;
}
bpf_link_init(&link->link, BPF_LINK_TYPE_RAW_TRACEPOINT,
&bpf_raw_tp_link_lops, prog);
link->btp = btp;
link->cookie = cookie;
err = bpf_link_prime(&link->link, &link_primer);
if (err) {
kfree(link);
goto out_put_btp;
}
err = bpf_probe_register(link->btp, link);
if (err) {
bpf_link_cleanup(&link_primer);
goto out_put_btp;
}
return bpf_link_settle(&link_primer);
out_put_btp:
bpf_put_raw_tracepoint(btp);
return err;
}
#define BPF_RAW_TRACEPOINT_OPEN_LAST_FIELD raw_tracepoint.cookie
static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
{
struct bpf_prog *prog;
void __user *tp_name;
__u64 cookie;
int fd;
if (CHECK_ATTR(BPF_RAW_TRACEPOINT_OPEN))
return -EINVAL;
prog = bpf_prog_get(attr->raw_tracepoint.prog_fd);
if (IS_ERR(prog))
return PTR_ERR(prog);
tp_name = u64_to_user_ptr(attr->raw_tracepoint.name);
cookie = attr->raw_tracepoint.cookie;
fd = bpf_raw_tp_link_attach(prog, tp_name, cookie);
if (fd < 0)
bpf_prog_put(prog);
return fd;
}
static enum bpf_prog_type
attach_type_to_prog_type(enum bpf_attach_type attach_type)
{
switch (attach_type) {
case BPF_CGROUP_INET_INGRESS:
case BPF_CGROUP_INET_EGRESS:
return BPF_PROG_TYPE_CGROUP_SKB;
case BPF_CGROUP_INET_SOCK_CREATE:
case BPF_CGROUP_INET_SOCK_RELEASE:
case BPF_CGROUP_INET4_POST_BIND:
case BPF_CGROUP_INET6_POST_BIND:
return BPF_PROG_TYPE_CGROUP_SOCK;
case BPF_CGROUP_INET4_BIND:
case BPF_CGROUP_INET6_BIND:
case BPF_CGROUP_INET4_CONNECT:
case BPF_CGROUP_INET6_CONNECT:
case BPF_CGROUP_UNIX_CONNECT:
case BPF_CGROUP_INET4_GETPEERNAME:
case BPF_CGROUP_INET6_GETPEERNAME:
case BPF_CGROUP_UNIX_GETPEERNAME:
case BPF_CGROUP_INET4_GETSOCKNAME:
case BPF_CGROUP_INET6_GETSOCKNAME:
case BPF_CGROUP_UNIX_GETSOCKNAME:
case BPF_CGROUP_UDP4_SENDMSG:
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UNIX_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
case BPF_CGROUP_UNIX_RECVMSG:
return BPF_PROG_TYPE_CGROUP_SOCK_ADDR;
case BPF_CGROUP_SOCK_OPS:
return BPF_PROG_TYPE_SOCK_OPS;
case BPF_CGROUP_DEVICE:
return BPF_PROG_TYPE_CGROUP_DEVICE;
case BPF_SK_MSG_VERDICT:
return BPF_PROG_TYPE_SK_MSG;
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
case BPF_SK_SKB_VERDICT:
return BPF_PROG_TYPE_SK_SKB;
case BPF_LIRC_MODE2:
return BPF_PROG_TYPE_LIRC_MODE2;
case BPF_FLOW_DISSECTOR:
return BPF_PROG_TYPE_FLOW_DISSECTOR;
case BPF_CGROUP_SYSCTL:
return BPF_PROG_TYPE_CGROUP_SYSCTL;
case BPF_CGROUP_GETSOCKOPT:
case BPF_CGROUP_SETSOCKOPT:
return BPF_PROG_TYPE_CGROUP_SOCKOPT;
case BPF_TRACE_ITER:
case BPF_TRACE_RAW_TP:
case BPF_TRACE_FENTRY:
case BPF_TRACE_FEXIT:
case BPF_MODIFY_RETURN:
return BPF_PROG_TYPE_TRACING;
case BPF_LSM_MAC:
return BPF_PROG_TYPE_LSM;
case BPF_SK_LOOKUP:
return BPF_PROG_TYPE_SK_LOOKUP;
case BPF_XDP:
return BPF_PROG_TYPE_XDP;
case BPF_LSM_CGROUP:
return BPF_PROG_TYPE_LSM;
case BPF_TCX_INGRESS:
case BPF_TCX_EGRESS:
case BPF_NETKIT_PRIMARY:
case BPF_NETKIT_PEER:
return BPF_PROG_TYPE_SCHED_CLS;
default:
return BPF_PROG_TYPE_UNSPEC;
}
}
static int bpf_prog_attach_check_attach_type(const struct bpf_prog *prog,
enum bpf_attach_type attach_type)
{
enum bpf_prog_type ptype;
switch (prog->type) {
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
case BPF_PROG_TYPE_SK_LOOKUP:
return attach_type == prog->expected_attach_type ? 0 : -EINVAL;
case BPF_PROG_TYPE_CGROUP_SKB:
if (!bpf_token_capable(prog->aux->token, CAP_NET_ADMIN))
/* cg-skb progs can be loaded by unpriv user.
* check permissions at attach time.
*/
return -EPERM;
ptype = attach_type_to_prog_type(attach_type);
if (prog->type != ptype)
return -EINVAL;
return prog->enforce_expected_attach_type &&
prog->expected_attach_type != attach_type ?
-EINVAL : 0;
case BPF_PROG_TYPE_EXT:
return 0;
case BPF_PROG_TYPE_NETFILTER:
if (attach_type != BPF_NETFILTER)
return -EINVAL;
return 0;
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_TRACEPOINT:
if (attach_type != BPF_PERF_EVENT)
return -EINVAL;
return 0;
case BPF_PROG_TYPE_KPROBE:
if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI &&
attach_type != BPF_TRACE_KPROBE_MULTI)
return -EINVAL;
if (prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION &&
attach_type != BPF_TRACE_KPROBE_SESSION)
return -EINVAL;
if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI &&
attach_type != BPF_TRACE_UPROBE_MULTI)
return -EINVAL;
if (attach_type != BPF_PERF_EVENT &&
attach_type != BPF_TRACE_KPROBE_MULTI &&
attach_type != BPF_TRACE_KPROBE_SESSION &&
attach_type != BPF_TRACE_UPROBE_MULTI)
return -EINVAL;
return 0;
case BPF_PROG_TYPE_SCHED_CLS:
if (attach_type != BPF_TCX_INGRESS &&
attach_type != BPF_TCX_EGRESS &&
attach_type != BPF_NETKIT_PRIMARY &&
attach_type != BPF_NETKIT_PEER)
return -EINVAL;
return 0;
default:
ptype = attach_type_to_prog_type(attach_type);
if (ptype == BPF_PROG_TYPE_UNSPEC || ptype != prog->type)
return -EINVAL;
return 0;
}
}
#define BPF_PROG_ATTACH_LAST_FIELD expected_revision
#define BPF_F_ATTACH_MASK_BASE \
(BPF_F_ALLOW_OVERRIDE | \
BPF_F_ALLOW_MULTI | \
BPF_F_REPLACE)
#define BPF_F_ATTACH_MASK_MPROG \
(BPF_F_REPLACE | \
BPF_F_BEFORE | \
BPF_F_AFTER | \
BPF_F_ID | \
BPF_F_LINK)
static int bpf_prog_attach(const union bpf_attr *attr)
{
enum bpf_prog_type ptype;
struct bpf_prog *prog;
int ret;
if (CHECK_ATTR(BPF_PROG_ATTACH))
return -EINVAL;
ptype = attach_type_to_prog_type(attr->attach_type);
if (ptype == BPF_PROG_TYPE_UNSPEC)
return -EINVAL;
if (bpf_mprog_supported(ptype)) {
if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
return -EINVAL;
} else {
if (attr->attach_flags & ~BPF_F_ATTACH_MASK_BASE)
return -EINVAL;
if (attr->relative_fd ||
attr->expected_revision)
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;
}
switch (ptype) {
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_SK_MSG:
ret = sock_map_get_from_fd(attr, prog);
break;
case BPF_PROG_TYPE_LIRC_MODE2:
ret = lirc_prog_attach(attr, prog);
break;
case BPF_PROG_TYPE_FLOW_DISSECTOR:
ret = netns_bpf_prog_attach(attr, prog);
break;
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SKB:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_LSM:
if (ptype == BPF_PROG_TYPE_LSM &&
prog->expected_attach_type != BPF_LSM_CGROUP)
ret = -EINVAL;
else
ret = cgroup_bpf_prog_attach(attr, ptype, prog);
break;
case BPF_PROG_TYPE_SCHED_CLS:
if (attr->attach_type == BPF_TCX_INGRESS ||
attr->attach_type == BPF_TCX_EGRESS)
ret = tcx_prog_attach(attr, prog);
else
ret = netkit_prog_attach(attr, prog);
break;
default:
ret = -EINVAL;
}
if (ret)
bpf_prog_put(prog);
return ret;
}
#define BPF_PROG_DETACH_LAST_FIELD expected_revision
static int bpf_prog_detach(const union bpf_attr *attr)
{
struct bpf_prog *prog = NULL;
enum bpf_prog_type ptype;
int ret;
if (CHECK_ATTR(BPF_PROG_DETACH))
return -EINVAL;
ptype = attach_type_to_prog_type(attr->attach_type);
if (bpf_mprog_supported(ptype)) {
if (ptype == BPF_PROG_TYPE_UNSPEC)
return -EINVAL;
if (attr->attach_flags & ~BPF_F_ATTACH_MASK_MPROG)
return -EINVAL;
if (attr->attach_bpf_fd) {
prog = bpf_prog_get_type(attr->attach_bpf_fd, ptype);
if (IS_ERR(prog))
return PTR_ERR(prog);
}
} else if (attr->attach_flags ||
attr->relative_fd ||
attr->expected_revision) {
return -EINVAL;
}
switch (ptype) {
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_SK_SKB:
ret = sock_map_prog_detach(attr, ptype);
break;
case BPF_PROG_TYPE_LIRC_MODE2:
ret = lirc_prog_detach(attr);
break;
case BPF_PROG_TYPE_FLOW_DISSECTOR:
ret = netns_bpf_prog_detach(attr, ptype);
break;
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SKB:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_LSM:
ret = cgroup_bpf_prog_detach(attr, ptype);
break;
case BPF_PROG_TYPE_SCHED_CLS:
if (attr->attach_type == BPF_TCX_INGRESS ||
attr->attach_type == BPF_TCX_EGRESS)
ret = tcx_prog_detach(attr, prog);
else
ret = netkit_prog_detach(attr, prog);
break;
default:
ret = -EINVAL;
}
if (prog)
bpf_prog_put(prog);
return ret;
}
#define BPF_PROG_QUERY_LAST_FIELD query.revision
static int bpf_prog_query(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
if (!bpf_net_capable())
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_INET_SOCK_RELEASE:
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_UNIX_CONNECT:
case BPF_CGROUP_INET4_GETPEERNAME:
case BPF_CGROUP_INET6_GETPEERNAME:
case BPF_CGROUP_UNIX_GETPEERNAME:
case BPF_CGROUP_INET4_GETSOCKNAME:
case BPF_CGROUP_INET6_GETSOCKNAME:
case BPF_CGROUP_UNIX_GETSOCKNAME:
case BPF_CGROUP_UDP4_SENDMSG:
case BPF_CGROUP_UDP6_SENDMSG:
case BPF_CGROUP_UNIX_SENDMSG:
case BPF_CGROUP_UDP4_RECVMSG:
case BPF_CGROUP_UDP6_RECVMSG:
case BPF_CGROUP_UNIX_RECVMSG:
case BPF_CGROUP_SOCK_OPS:
case BPF_CGROUP_DEVICE:
case BPF_CGROUP_SYSCTL:
case BPF_CGROUP_GETSOCKOPT:
case BPF_CGROUP_SETSOCKOPT:
case BPF_LSM_CGROUP:
return cgroup_bpf_prog_query(attr, uattr);
case BPF_LIRC_MODE2:
return lirc_prog_query(attr, uattr);
case BPF_FLOW_DISSECTOR:
case BPF_SK_LOOKUP:
return netns_bpf_prog_query(attr, uattr);
case BPF_SK_SKB_STREAM_PARSER:
case BPF_SK_SKB_STREAM_VERDICT:
case BPF_SK_MSG_VERDICT:
case BPF_SK_SKB_VERDICT:
return sock_map_bpf_prog_query(attr, uattr);
case BPF_TCX_INGRESS:
case BPF_TCX_EGRESS:
return tcx_prog_query(attr, uattr);
case BPF_NETKIT_PRIMARY:
case BPF_NETKIT_PEER:
return netkit_prog_query(attr, uattr);
default:
return -EINVAL;
}
}
#define BPF_PROG_TEST_RUN_LAST_FIELD test.batch_size
static int bpf_prog_test_run(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_prog *prog;
int ret = -ENOTSUPP;
if (CHECK_ATTR(BPF_PROG_TEST_RUN))
return -EINVAL;
if ((attr->test.ctx_size_in && !attr->test.ctx_in) ||
(!attr->test.ctx_size_in && attr->test.ctx_in))
return -EINVAL;
if ((attr->test.ctx_size_out && !attr->test.ctx_out) ||
(!attr->test.ctx_size_out && attr->test.ctx_out))
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;
}
struct bpf_map *bpf_map_get_curr_or_next(u32 *id)
{
struct bpf_map *map;
spin_lock_bh(&map_idr_lock);
again:
map = idr_get_next(&map_idr, id);
if (map) {
map = __bpf_map_inc_not_zero(map, false);
if (IS_ERR(map)) {
(*id)++;
goto again;
}
}
spin_unlock_bh(&map_idr_lock);
return map;
}
struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id)
{
struct bpf_prog *prog;
spin_lock_bh(&prog_idr_lock);
again:
prog = idr_get_next(&prog_idr, id);
if (prog) {
prog = bpf_prog_inc_not_zero(prog);
if (IS_ERR(prog)) {
(*id)++;
goto again;
}
}
spin_unlock_bh(&prog_idr_lock);
return prog;
}
#define BPF_PROG_GET_FD_BY_ID_LAST_FIELD prog_id
struct bpf_prog *bpf_prog_by_id(u32 id)
{
struct bpf_prog *prog;
if (!id)
return ERR_PTR(-ENOENT);
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);
return prog;
}
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;
prog = bpf_prog_by_id(id);
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_with_uref(map);
return fd;
}
static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog,
unsigned long addr, u32 *off,
u32 *type)
{
const struct bpf_map *map;
int i;
mutex_lock(&prog->aux->used_maps_mutex);
for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) {
map = prog->aux->used_maps[i];
if (map == (void *)addr) {
*type = BPF_PSEUDO_MAP_FD;
goto out;
}
if (!map->ops->map_direct_value_meta)
continue;
if (!map->ops->map_direct_value_meta(map, addr, off)) {
*type = BPF_PSEUDO_MAP_VALUE;
goto out;
}
}
map = NULL;
out:
mutex_unlock(&prog->aux->used_maps_mutex);
return map;
}
static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog,
const struct cred *f_cred)
{
const struct bpf_map *map;
struct bpf_insn *insns;
u32 off, type;
u64 imm;
u8 code;
int i;
insns = kmemdup(prog->insnsi, bpf_prog_insn_size(prog),
GFP_USER);
if (!insns)
return insns;
for (i = 0; i < prog->len; i++) {
code = insns[i].code;
if (code == (BPF_JMP | BPF_TAIL_CALL)) {
insns[i].code = BPF_JMP | BPF_CALL;
insns[i].imm = BPF_FUNC_tail_call;
/* fall-through */
}
if (code == (BPF_JMP | BPF_CALL) ||
code == (BPF_JMP | BPF_CALL_ARGS)) {
if (code == (BPF_JMP | BPF_CALL_ARGS))
insns[i].code = BPF_JMP | BPF_CALL;
if (!bpf_dump_raw_ok(f_cred))
insns[i].imm = 0;
continue;
}
if (BPF_CLASS(code) == BPF_LDX && BPF_MODE(code) == BPF_PROBE_MEM) {
insns[i].code = BPF_LDX | BPF_SIZE(code) | BPF_MEM;
continue;
}
if ((BPF_CLASS(code) == BPF_LDX || BPF_CLASS(code) == BPF_STX ||
BPF_CLASS(code) == BPF_ST) && BPF_MODE(code) == BPF_PROBE_MEM32) {
insns[i].code = BPF_CLASS(code) | BPF_SIZE(code) | BPF_MEM;
continue;
}
if (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, &off, &type);
if (map) {
insns[i].src_reg = type;
insns[i].imm = map->id;
insns[i + 1].imm = off;
continue;
}
}
return insns;
}
static int set_info_rec_size(struct bpf_prog_info *info)
{
/*
* Ensure info.*_rec_size is the same as kernel expected size
*
* or
*
* Only allow zero *_rec_size if both _rec_size and _cnt are
* zero. In this case, the kernel will set the expected
* _rec_size back to the info.
*/
if ((info->nr_func_info || info->func_info_rec_size) &&
info->func_info_rec_size != sizeof(struct bpf_func_info))
return -EINVAL;
if ((info->nr_line_info || info->line_info_rec_size) &&
info->line_info_rec_size != sizeof(struct bpf_line_info))
return -EINVAL;
if ((info->nr_jited_line_info || info->jited_line_info_rec_size) &&
info->jited_line_info_rec_size != sizeof(__u64))
return -EINVAL;
info->func_info_rec_size = sizeof(struct bpf_func_info);
info->line_info_rec_size = sizeof(struct bpf_line_info);
info->jited_line_info_rec_size = sizeof(__u64);
return 0;
}
static int bpf_prog_get_info_by_fd(struct file *file,
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 btf *attach_btf = bpf_prog_get_target_btf(prog);
struct bpf_prog_info info;
u32 info_len = attr->info.info_len;
struct bpf_prog_kstats stats;
char __user *uinsns;
u32 ulen;
int err;
err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
if (err)
return err;
info_len = min_t(u32, sizeof(info), info_len);
memset(&info, 0, sizeof(info));
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);
info.gpl_compatible = prog->gpl_compatible;
memcpy(info.tag, prog->tag, sizeof(prog->tag));
memcpy(info.name, prog->aux->name, sizeof(prog->aux->name));
mutex_lock(&prog->aux->used_maps_mutex);
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])) {
mutex_unlock(&prog->aux->used_maps_mutex);
return -EFAULT;
}
}
mutex_unlock(&prog->aux->used_maps_mutex);
err = set_info_rec_size(&info);
if (err)
return err;
bpf_prog_get_stats(prog, &stats);
info.run_time_ns = stats.nsecs;
info.run_cnt = stats.cnt;
info.recursion_misses = stats.misses;
info.verified_insns = prog->aux->verified_insns;
if (!bpf_capable()) {
info.jited_prog_len = 0;
info.xlated_prog_len = 0;
info.nr_jited_ksyms = 0;
info.nr_jited_func_lens = 0;
info.nr_func_info = 0;
info.nr_line_info = 0;
info.nr_jited_line_info = 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(file->f_cred)) {
info.xlated_prog_insns = 0;
goto done;
}
insns_sanitized = bpf_insn_prepare_dump(prog, file->f_cred);
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_offloaded(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;
if (prog->aux->func_cnt) {
u32 i;
info.jited_prog_len = 0;
for (i = 0; i < prog->aux->func_cnt; i++)
info.jited_prog_len += prog->aux->func[i]->jited_len;
} else {
info.jited_prog_len = prog->jited_len;
}
if (info.jited_prog_len && ulen) {
if (bpf_dump_raw_ok(file->f_cred)) {
uinsns = u64_to_user_ptr(info.jited_prog_insns);
ulen = min_t(u32, info.jited_prog_len, ulen);
/* for multi-function programs, copy the JITed
* instructions for all the functions
*/
if (prog->aux->func_cnt) {
u32 len, free, i;
u8 *img;
free = ulen;
for (i = 0; i < prog->aux->func_cnt; i++) {
len = prog->aux->func[i]->jited_len;
len = min_t(u32, len, free);
img = (u8 *) prog->aux->func[i]->bpf_func;
if (copy_to_user(uinsns, img, len))
return -EFAULT;
uinsns += len;
free -= len;
if (!free)
break;
}
} else {
if (copy_to_user(uinsns, prog->bpf_func, ulen))
return -EFAULT;
}
} else {
info.jited_prog_insns = 0;
}
}
ulen = info.nr_jited_ksyms;
info.nr_jited_ksyms = prog->aux->func_cnt ? : 1;
if (ulen) {
if (bpf_dump_raw_ok(file->f_cred)) {
unsigned long ksym_addr;
u64 __user *user_ksyms;
u32 i;
/* copy the address of the kernel symbol
* corresponding to each function
*/
ulen = min_t(u32, info.nr_jited_ksyms, ulen);
user_ksyms = u64_to_user_ptr(info.jited_ksyms);
if (prog->aux->func_cnt) {
for (i = 0; i < ulen; i++) {
ksym_addr = (unsigned long)
prog->aux->func[i]->bpf_func;
if (put_user((u64) ksym_addr,
&user_ksyms[i]))
return -EFAULT;
}
} else {
ksym_addr = (unsigned long) prog->bpf_func;
if (put_user((u64) ksym_addr, &user_ksyms[0]))
return -EFAULT;
}
} else {
info.jited_ksyms = 0;
}
}
ulen = info.nr_jited_func_lens;
info.nr_jited_func_lens = prog->aux->func_cnt ? : 1;
if (ulen) {
if (bpf_dump_raw_ok(file->f_cred)) {
u32 __user *user_lens;
u32 func_len, i;
/* copy the JITed image lengths for each function */
ulen = min_t(u32, info.nr_jited_func_lens, ulen);
user_lens = u64_to_user_ptr(info.jited_func_lens);
if (prog->aux->func_cnt) {
for (i = 0; i < ulen; i++) {
func_len =
prog->aux->func[i]->jited_len;
if (put_user(func_len, &user_lens[i]))
return -EFAULT;
}
} else {
func_len = prog->jited_len;
if (put_user(func_len, &user_lens[0]))
return -EFAULT;
}
} else {
info.jited_func_lens = 0;
}
}
if (prog->aux->btf)
info.btf_id = btf_obj_id(prog->aux->btf);
info.attach_btf_id = prog->aux->attach_btf_id;
if (attach_btf)
info.attach_btf_obj_id = btf_obj_id(attach_btf);
ulen = info.nr_func_info;
info.nr_func_info = prog->aux->func_info_cnt;
if (info.nr_func_info && ulen) {
char __user *user_finfo;
user_finfo = u64_to_user_ptr(info.func_info);
ulen = min_t(u32, info.nr_func_info, ulen);
if (copy_to_user(user_finfo, prog->aux->func_info,
info.func_info_rec_size * ulen))
return -EFAULT;
}
ulen = info.nr_line_info;
info.nr_line_info = prog->aux->nr_linfo;
if (info.nr_line_info && ulen) {
__u8 __user *user_linfo;
user_linfo = u64_to_user_ptr(info.line_info);
ulen = min_t(u32, info.nr_line_info, ulen);
if (copy_to_user(user_linfo, prog->aux->linfo,
info.line_info_rec_size * ulen))
return -EFAULT;
}
ulen = info.nr_jited_line_info;
if (prog->aux->jited_linfo)
info.nr_jited_line_info = prog->aux->nr_linfo;
else
info.nr_jited_line_info = 0;
if (info.nr_jited_line_info && ulen) {
if (bpf_dump_raw_ok(file->f_cred)) {
unsigned long line_addr;
__u64 __user *user_linfo;
u32 i;
user_linfo = u64_to_user_ptr(info.jited_line_info);
ulen = min_t(u32, info.nr_jited_line_info, ulen);
for (i = 0; i < ulen; i++) {
line_addr = (unsigned long)prog->aux->jited_linfo[i];
if (put_user((__u64)line_addr, &user_linfo[i]))
return -EFAULT;
}
} else {
info.jited_line_info = 0;
}
}
ulen = info.nr_prog_tags;
info.nr_prog_tags = prog->aux->func_cnt ? : 1;
if (ulen) {
__u8 __user (*user_prog_tags)[BPF_TAG_SIZE];
u32 i;
user_prog_tags = u64_to_user_ptr(info.prog_tags);
ulen = min_t(u32, info.nr_prog_tags, ulen);
if (prog->aux->func_cnt) {
for (i = 0; i < ulen; i++) {
if (copy_to_user(user_prog_tags[i],
prog->aux->func[i]->tag,
BPF_TAG_SIZE))
return -EFAULT;
}
} else {
if (copy_to_user(user_prog_tags[0],
prog->tag, BPF_TAG_SIZE))
return -EFAULT;
}
}
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 file *file,
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 = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
if (err)
return err;
info_len = min_t(u32, sizeof(info), info_len);
memset(&info, 0, sizeof(info));
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;
info.map_extra = map->map_extra;
memcpy(info.name, map->name, sizeof(map->name));
if (map->btf) {
info.btf_id = btf_obj_id(map->btf);
info.btf_key_type_id = map->btf_key_type_id;
info.btf_value_type_id = map->btf_value_type_id;
}
info.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id;
if (map->map_type == BPF_MAP_TYPE_STRUCT_OPS)
bpf_map_struct_ops_info_fill(&info, map);
if (bpf_map_is_offloaded(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;
}
static int bpf_btf_get_info_by_fd(struct file *file,
struct btf *btf,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_btf_info __user *uinfo = u64_to_user_ptr(attr->info.info);
u32 info_len = attr->info.info_len;
int err;
err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(*uinfo), info_len);
if (err)
return err;
return btf_get_info_by_fd(btf, attr, uattr);
}
static int bpf_link_get_info_by_fd(struct file *file,
struct bpf_link *link,
const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
struct bpf_link_info __user *uinfo = u64_to_user_ptr(attr->info.info);
struct bpf_link_info info;
u32 info_len = attr->info.info_len;
int err;
err = bpf_check_uarg_tail_zero(USER_BPFPTR(uinfo), sizeof(info), info_len);
if (err)
return err;
info_len = min_t(u32, sizeof(info), info_len);
memset(&info, 0, sizeof(info));
if (copy_from_user(&info, uinfo, info_len))
return -EFAULT;
info.type = link->type;
info.id = link->id;
if (link->prog)
info.prog_id = link->prog->aux->id;
if (link->ops->fill_link_info) {
err = link->ops->fill_link_info(link, &info);
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)
{
if (CHECK_ATTR(BPF_OBJ_GET_INFO_BY_FD))
return -EINVAL;
CLASS(fd, f)(attr->info.bpf_fd);
if (fd_empty(f))
return -EBADFD;
if (fd_file(f)->f_op == &bpf_prog_fops)
return bpf_prog_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
uattr);
else if (fd_file(f)->f_op == &bpf_map_fops)
return bpf_map_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr,
uattr);
else if (fd_file(f)->f_op == &btf_fops)
return bpf_btf_get_info_by_fd(fd_file(f), fd_file(f)->private_data, attr, uattr);
else if (fd_file(f)->f_op == &bpf_link_fops || fd_file(f)->f_op == &bpf_link_fops_poll)
return bpf_link_get_info_by_fd(fd_file(f), fd_file(f)->private_data,
attr, uattr);
return -EINVAL;
}
#define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
{
struct bpf_token *token = NULL;
if (CHECK_ATTR(BPF_BTF_LOAD))
return -EINVAL;
if (attr->btf_flags & ~BPF_F_TOKEN_FD)
return -EINVAL;
if (attr->btf_flags & BPF_F_TOKEN_FD) {
token = bpf_token_get_from_fd(attr->btf_token_fd);
if (IS_ERR(token))
return PTR_ERR(token);
if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
bpf_token_put(token);
token = NULL;
}
}
if (!bpf_token_capable(token, CAP_BPF)) {
bpf_token_put(token);
return -EPERM;
}
bpf_token_put(token);
return btf_new_fd(attr, uattr, uattr_size);
}
#define BPF_BTF_GET_FD_BY_ID_LAST_FIELD btf_id
static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_BTF_GET_FD_BY_ID))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
return btf_get_fd_by_id(attr->btf_id);
}
static int bpf_task_fd_query_copy(const union bpf_attr *attr,
union bpf_attr __user *uattr,
u32 prog_id, u32 fd_type,
const char *buf, u64 probe_offset,
u64 probe_addr)
{
char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
u32 len = buf ? strlen(buf) : 0, input_len;
int err = 0;
if (put_user(len, &uattr->task_fd_query.buf_len))
return -EFAULT;
input_len = attr->task_fd_query.buf_len;
if (input_len && ubuf) {
if (!len) {
/* nothing to copy, just make ubuf NULL terminated */
char zero = '\0';
if (put_user(zero, ubuf))
return -EFAULT;
} else if (input_len >= len + 1) {
/* ubuf can hold the string with NULL terminator */
if (copy_to_user(ubuf, buf, len + 1))
return -EFAULT;
} else {
/* ubuf cannot hold the string with NULL terminator,
* do a partial copy with NULL terminator.
*/
char zero = '\0';
err = -ENOSPC;
if (copy_to_user(ubuf, buf, input_len - 1))
return -EFAULT;
if (put_user(zero, ubuf + input_len - 1))
return -EFAULT;
}
}
if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
put_user(fd_type, &uattr->task_fd_query.fd_type) ||
put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
put_user(probe_addr, &uattr->task_fd_query.probe_addr))
return -EFAULT;
return err;
}
#define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
static int bpf_task_fd_query(const union bpf_attr *attr,
union bpf_attr __user *uattr)
{
pid_t pid = attr->task_fd_query.pid;
u32 fd = attr->task_fd_query.fd;
const struct perf_event *event;
struct task_struct *task;
struct file *file;
int err;
if (CHECK_ATTR(BPF_TASK_FD_QUERY))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (attr->task_fd_query.flags != 0)
return -EINVAL;
rcu_read_lock();
task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
rcu_read_unlock();
if (!task)
return -ENOENT;
err = 0;
file = fget_task(task, fd);
put_task_struct(task);
if (!file)
return -EBADF;
if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
struct bpf_link *link = file->private_data;
if (link->ops == &bpf_raw_tp_link_lops) {
struct bpf_raw_tp_link *raw_tp =
container_of(link, struct bpf_raw_tp_link, link);
struct bpf_raw_event_map *btp = raw_tp->btp;
err = bpf_task_fd_query_copy(attr, uattr,
raw_tp->link.prog->aux->id,
BPF_FD_TYPE_RAW_TRACEPOINT,
btp->tp->name, 0, 0);
goto put_file;
}
goto out_not_supp;
}
event = perf_get_event(file);
if (!IS_ERR(event)) {
u64 probe_offset, probe_addr;
u32 prog_id, fd_type;
const char *buf;
err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
&buf, &probe_offset,
&probe_addr, NULL);
if (!err)
err = bpf_task_fd_query_copy(attr, uattr, prog_id,
fd_type, buf,
probe_offset,
probe_addr);
goto put_file;
}
out_not_supp:
err = -ENOTSUPP;
put_file:
fput(file);
return err;
}
#define BPF_MAP_BATCH_LAST_FIELD batch.flags
#define BPF_DO_BATCH(fn, ...) \
do { \
if (!fn) { \
err = -ENOTSUPP; \
goto err_put; \
} \
err = fn(__VA_ARGS__); \
} while (0)
static int bpf_map_do_batch(const union bpf_attr *attr,
union bpf_attr __user *uattr,
int cmd)
{
bool has_read = cmd == BPF_MAP_LOOKUP_BATCH ||
cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH;
bool has_write = cmd != BPF_MAP_LOOKUP_BATCH;
struct bpf_map *map;
int err;
if (CHECK_ATTR(BPF_MAP_BATCH))
return -EINVAL;
CLASS(fd, f)(attr->batch.map_fd);
map = __bpf_map_get(f);
if (IS_ERR(map))
return PTR_ERR(map);
if (has_write)
bpf_map_write_active_inc(map);
if (has_read && !(map_get_sys_perms(map, f) & FMODE_CAN_READ)) {
err = -EPERM;
goto err_put;
}
if (has_write && !(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
err = -EPERM;
goto err_put;
}
if (cmd == BPF_MAP_LOOKUP_BATCH)
BPF_DO_BATCH(map->ops->map_lookup_batch, map, attr, uattr);
else if (cmd == BPF_MAP_LOOKUP_AND_DELETE_BATCH)
BPF_DO_BATCH(map->ops->map_lookup_and_delete_batch, map, attr, uattr);
else if (cmd == BPF_MAP_UPDATE_BATCH)
BPF_DO_BATCH(map->ops->map_update_batch, map, fd_file(f), attr, uattr);
else
BPF_DO_BATCH(map->ops->map_delete_batch, map, attr, uattr);
err_put:
if (has_write) {
maybe_wait_bpf_programs(map);
bpf_map_write_active_dec(map);
}
return err;
}
#define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.pid
static int link_create(union bpf_attr *attr, bpfptr_t uattr)
{
struct bpf_prog *prog;
int ret;
if (CHECK_ATTR(BPF_LINK_CREATE))
return -EINVAL;
if (attr->link_create.attach_type == BPF_STRUCT_OPS)
return bpf_struct_ops_link_create(attr);
prog = bpf_prog_get(attr->link_create.prog_fd);
if (IS_ERR(prog))
return PTR_ERR(prog);
ret = bpf_prog_attach_check_attach_type(prog,
attr->link_create.attach_type);
if (ret)
goto out;
switch (prog->type) {
case BPF_PROG_TYPE_CGROUP_SKB:
case BPF_PROG_TYPE_CGROUP_SOCK:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
case BPF_PROG_TYPE_SOCK_OPS:
case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SYSCTL:
case BPF_PROG_TYPE_CGROUP_SOCKOPT:
ret = cgroup_bpf_link_attach(attr, prog);
break;
case BPF_PROG_TYPE_EXT:
ret = bpf_tracing_prog_attach(prog,
attr->link_create.target_fd,
attr->link_create.target_btf_id,
attr->link_create.tracing.cookie);
break;
case BPF_PROG_TYPE_LSM:
case BPF_PROG_TYPE_TRACING:
if (attr->link_create.attach_type != prog->expected_attach_type) {
ret = -EINVAL;
goto out;
}
if (prog->expected_attach_type == BPF_TRACE_RAW_TP)
ret = bpf_raw_tp_link_attach(prog, NULL, attr->link_create.tracing.cookie);
else if (prog->expected_attach_type == BPF_TRACE_ITER)
ret = bpf_iter_link_attach(attr, uattr, prog);
else if (prog->expected_attach_type == BPF_LSM_CGROUP)
ret = cgroup_bpf_link_attach(attr, prog);
else
ret = bpf_tracing_prog_attach(prog,
attr->link_create.target_fd,
attr->link_create.target_btf_id,
attr->link_create.tracing.cookie);
break;
case BPF_PROG_TYPE_FLOW_DISSECTOR:
case BPF_PROG_TYPE_SK_LOOKUP:
ret = netns_bpf_link_create(attr, prog);
break;
case BPF_PROG_TYPE_SK_MSG:
case BPF_PROG_TYPE_SK_SKB:
ret = sock_map_link_create(attr, prog);
break;
#ifdef CONFIG_NET
case BPF_PROG_TYPE_XDP:
ret = bpf_xdp_link_attach(attr, prog);
break;
case BPF_PROG_TYPE_SCHED_CLS:
if (attr->link_create.attach_type == BPF_TCX_INGRESS ||
attr->link_create.attach_type == BPF_TCX_EGRESS)
ret = tcx_link_attach(attr, prog);
else
ret = netkit_link_attach(attr, prog);
break;
case BPF_PROG_TYPE_NETFILTER:
ret = bpf_nf_link_attach(attr, prog);
break;
#endif
case BPF_PROG_TYPE_PERF_EVENT:
case BPF_PROG_TYPE_TRACEPOINT:
ret = bpf_perf_link_attach(attr, prog);
break;
case BPF_PROG_TYPE_KPROBE:
if (attr->link_create.attach_type == BPF_PERF_EVENT)
ret = bpf_perf_link_attach(attr, prog);
else if (attr->link_create.attach_type == BPF_TRACE_KPROBE_MULTI ||
attr->link_create.attach_type == BPF_TRACE_KPROBE_SESSION)
ret = bpf_kprobe_multi_link_attach(attr, prog);
else if (attr->link_create.attach_type == BPF_TRACE_UPROBE_MULTI)
ret = bpf_uprobe_multi_link_attach(attr, prog);
break;
default:
ret = -EINVAL;
}
out:
if (ret < 0)
bpf_prog_put(prog);
return ret;
}
static int link_update_map(struct bpf_link *link, union bpf_attr *attr)
{
struct bpf_map *new_map, *old_map = NULL;
int ret;
new_map = bpf_map_get(attr->link_update.new_map_fd);
if (IS_ERR(new_map))
return PTR_ERR(new_map);
if (attr->link_update.flags & BPF_F_REPLACE) {
old_map = bpf_map_get(attr->link_update.old_map_fd);
if (IS_ERR(old_map)) {
ret = PTR_ERR(old_map);
goto out_put;
}
} else if (attr->link_update.old_map_fd) {
ret = -EINVAL;
goto out_put;
}
ret = link->ops->update_map(link, new_map, old_map);
if (old_map)
bpf_map_put(old_map);
out_put:
bpf_map_put(new_map);
return ret;
}
#define BPF_LINK_UPDATE_LAST_FIELD link_update.old_prog_fd
static int link_update(union bpf_attr *attr)
{
struct bpf_prog *old_prog = NULL, *new_prog;
struct bpf_link *link;
u32 flags;
int ret;
if (CHECK_ATTR(BPF_LINK_UPDATE))
return -EINVAL;
flags = attr->link_update.flags;
if (flags & ~BPF_F_REPLACE)
return -EINVAL;
link = bpf_link_get_from_fd(attr->link_update.link_fd);
if (IS_ERR(link))
return PTR_ERR(link);
if (link->ops->update_map) {
ret = link_update_map(link, attr);
goto out_put_link;
}
new_prog = bpf_prog_get(attr->link_update.new_prog_fd);
if (IS_ERR(new_prog)) {
ret = PTR_ERR(new_prog);
goto out_put_link;
}
if (flags & BPF_F_REPLACE) {
old_prog = bpf_prog_get(attr->link_update.old_prog_fd);
if (IS_ERR(old_prog)) {
ret = PTR_ERR(old_prog);
old_prog = NULL;
goto out_put_progs;
}
} else if (attr->link_update.old_prog_fd) {
ret = -EINVAL;
goto out_put_progs;
}
if (link->ops->update_prog)
ret = link->ops->update_prog(link, new_prog, old_prog);
else
ret = -EINVAL;
out_put_progs:
if (old_prog)
bpf_prog_put(old_prog);
if (ret)
bpf_prog_put(new_prog);
out_put_link:
bpf_link_put_direct(link);
return ret;
}
#define BPF_LINK_DETACH_LAST_FIELD link_detach.link_fd
static int link_detach(union bpf_attr *attr)
{
struct bpf_link *link;
int ret;
if (CHECK_ATTR(BPF_LINK_DETACH))
return -EINVAL;
link = bpf_link_get_from_fd(attr->link_detach.link_fd);
if (IS_ERR(link))
return PTR_ERR(link);
if (link->ops->detach)
ret = link->ops->detach(link);
else
ret = -EOPNOTSUPP;
bpf_link_put_direct(link);
return ret;
}
struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
{
return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(bpf_link_inc_not_zero);
struct bpf_link *bpf_link_by_id(u32 id)
{
struct bpf_link *link;
if (!id)
return ERR_PTR(-ENOENT);
spin_lock_bh(&link_idr_lock);
/* before link is "settled", ID is 0, pretend it doesn't exist yet */
link = idr_find(&link_idr, id);
if (link) {
if (link->id)
link = bpf_link_inc_not_zero(link);
else
link = ERR_PTR(-EAGAIN);
} else {
link = ERR_PTR(-ENOENT);
}
spin_unlock_bh(&link_idr_lock);
return link;
}
struct bpf_link *bpf_link_get_curr_or_next(u32 *id)
{
struct bpf_link *link;
spin_lock_bh(&link_idr_lock);
again:
link = idr_get_next(&link_idr, id);
if (link) {
link = bpf_link_inc_not_zero(link);
if (IS_ERR(link)) {
(*id)++;
goto again;
}
}
spin_unlock_bh(&link_idr_lock);
return link;
}
#define BPF_LINK_GET_FD_BY_ID_LAST_FIELD link_id
static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
{
struct bpf_link *link;
u32 id = attr->link_id;
int fd;
if (CHECK_ATTR(BPF_LINK_GET_FD_BY_ID))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
link = bpf_link_by_id(id);
if (IS_ERR(link))
return PTR_ERR(link);
fd = bpf_link_new_fd(link);
if (fd < 0)
bpf_link_put_direct(link);
return fd;
}
DEFINE_MUTEX(bpf_stats_enabled_mutex);
static int bpf_stats_release(struct inode *inode, struct file *file)
{
mutex_lock(&bpf_stats_enabled_mutex);
static_key_slow_dec(&bpf_stats_enabled_key.key);
mutex_unlock(&bpf_stats_enabled_mutex);
return 0;
}
static const struct file_operations bpf_stats_fops = {
.release = bpf_stats_release,
};
static int bpf_enable_runtime_stats(void)
{
int fd;
mutex_lock(&bpf_stats_enabled_mutex);
/* Set a very high limit to avoid overflow */
if (static_key_count(&bpf_stats_enabled_key.key) > INT_MAX / 2) {
mutex_unlock(&bpf_stats_enabled_mutex);
return -EBUSY;
}
fd = anon_inode_getfd("bpf-stats", &bpf_stats_fops, NULL, O_CLOEXEC);
if (fd >= 0)
static_key_slow_inc(&bpf_stats_enabled_key.key);
mutex_unlock(&bpf_stats_enabled_mutex);
return fd;
}
#define BPF_ENABLE_STATS_LAST_FIELD enable_stats.type
static int bpf_enable_stats(union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_ENABLE_STATS))
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
switch (attr->enable_stats.type) {
case BPF_STATS_RUN_TIME:
return bpf_enable_runtime_stats();
default:
break;
}
return -EINVAL;
}
#define BPF_ITER_CREATE_LAST_FIELD iter_create.flags
static int bpf_iter_create(union bpf_attr *attr)
{
struct bpf_link *link;
int err;
if (CHECK_ATTR(BPF_ITER_CREATE))
return -EINVAL;
if (attr->iter_create.flags)
return -EINVAL;
link = bpf_link_get_from_fd(attr->iter_create.link_fd);
if (IS_ERR(link))
return PTR_ERR(link);
err = bpf_iter_new_fd(link);
bpf_link_put_direct(link);
return err;
}
#define BPF_PROG_BIND_MAP_LAST_FIELD prog_bind_map.flags
static int bpf_prog_bind_map(union bpf_attr *attr)
{
struct bpf_prog *prog;
struct bpf_map *map;
struct bpf_map **used_maps_old, **used_maps_new;
int i, ret = 0;
if (CHECK_ATTR(BPF_PROG_BIND_MAP))
return -EINVAL;
if (attr->prog_bind_map.flags)
return -EINVAL;
prog = bpf_prog_get(attr->prog_bind_map.prog_fd);
if (IS_ERR(prog))
return PTR_ERR(prog);
map = bpf_map_get(attr->prog_bind_map.map_fd);
if (IS_ERR(map)) {
ret = PTR_ERR(map);
goto out_prog_put;
}
mutex_lock(&prog->aux->used_maps_mutex);
used_maps_old = prog->aux->used_maps;
for (i = 0; i < prog->aux->used_map_cnt; i++)
if (used_maps_old[i] == map) {
bpf_map_put(map);
goto out_unlock;
}
used_maps_new = kmalloc_array(prog->aux->used_map_cnt + 1,
sizeof(used_maps_new[0]),
GFP_KERNEL);
if (!used_maps_new) {
ret = -ENOMEM;
goto out_unlock;
}
/* The bpf program will not access the bpf map, but for the sake of
* simplicity, increase sleepable_refcnt for sleepable program as well.
*/
if (prog->sleepable)
atomic64_inc(&map->sleepable_refcnt);
memcpy(used_maps_new, used_maps_old,
sizeof(used_maps_old[0]) * prog->aux->used_map_cnt);
used_maps_new[prog->aux->used_map_cnt] = map;
prog->aux->used_map_cnt++;
prog->aux->used_maps = used_maps_new;
kfree(used_maps_old);
out_unlock:
mutex_unlock(&prog->aux->used_maps_mutex);
if (ret)
bpf_map_put(map);
out_prog_put:
bpf_prog_put(prog);
return ret;
}
#define BPF_TOKEN_CREATE_LAST_FIELD token_create.bpffs_fd
static int token_create(union bpf_attr *attr)
{
if (CHECK_ATTR(BPF_TOKEN_CREATE))
return -EINVAL;
/* no flags are supported yet */
if (attr->token_create.flags)
return -EINVAL;
return bpf_token_create(attr);
}
static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size)
{
union bpf_attr attr;
int err;
err = bpf_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) */
memset(&attr, 0, sizeof(attr));
if (copy_from_bpfptr(&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, uattr);
break;
case BPF_MAP_DELETE_ELEM:
err = map_delete_elem(&attr, uattr);
break;
case BPF_MAP_GET_NEXT_KEY:
err = map_get_next_key(&attr);
break;
case BPF_MAP_FREEZE:
err = map_freeze(&attr);
break;
case BPF_PROG_LOAD:
err = bpf_prog_load(&attr, uattr, size);
break;
case BPF_OBJ_PIN:
err = bpf_obj_pin(&attr);
break;
case BPF_OBJ_GET:
err = bpf_obj_get(&attr);
break;
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.user);
break;
case BPF_PROG_TEST_RUN:
err = bpf_prog_test_run(&attr, uattr.user);
break;
case BPF_PROG_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr.user,
&prog_idr, &prog_idr_lock);
break;
case BPF_MAP_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr.user,
&map_idr, &map_idr_lock);
break;
case BPF_BTF_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr.user,
&btf_idr, &btf_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.user);
break;
case BPF_RAW_TRACEPOINT_OPEN:
err = bpf_raw_tracepoint_open(&attr);
break;
case BPF_BTF_LOAD:
err = bpf_btf_load(&attr, uattr, size);
break;
case BPF_BTF_GET_FD_BY_ID:
err = bpf_btf_get_fd_by_id(&attr);
break;
case BPF_TASK_FD_QUERY:
err = bpf_task_fd_query(&attr, uattr.user);
break;
case BPF_MAP_LOOKUP_AND_DELETE_ELEM:
err = map_lookup_and_delete_elem(&attr);
break;
case BPF_MAP_LOOKUP_BATCH:
err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_LOOKUP_BATCH);
break;
case BPF_MAP_LOOKUP_AND_DELETE_BATCH:
err = bpf_map_do_batch(&attr, uattr.user,
BPF_MAP_LOOKUP_AND_DELETE_BATCH);
break;
case BPF_MAP_UPDATE_BATCH:
err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_UPDATE_BATCH);
break;
case BPF_MAP_DELETE_BATCH:
err = bpf_map_do_batch(&attr, uattr.user, BPF_MAP_DELETE_BATCH);
break;
case BPF_LINK_CREATE:
err = link_create(&attr, uattr);
break;
case BPF_LINK_UPDATE:
err = link_update(&attr);
break;
case BPF_LINK_GET_FD_BY_ID:
err = bpf_link_get_fd_by_id(&attr);
break;
case BPF_LINK_GET_NEXT_ID:
err = bpf_obj_get_next_id(&attr, uattr.user,
&link_idr, &link_idr_lock);
break;
case BPF_ENABLE_STATS:
err = bpf_enable_stats(&attr);
break;
case BPF_ITER_CREATE:
err = bpf_iter_create(&attr);
break;
case BPF_LINK_DETACH:
err = link_detach(&attr);
break;
case BPF_PROG_BIND_MAP:
err = bpf_prog_bind_map(&attr);
break;
case BPF_TOKEN_CREATE:
err = token_create(&attr);
break;
default:
err = -EINVAL;
break;
}
return err;
}
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
return __sys_bpf(cmd, USER_BPFPTR(uattr), size);
}
static bool syscall_prog_is_valid_access(int off, int size,
enum bpf_access_type type,
const struct bpf_prog *prog,
struct bpf_insn_access_aux *info)
{
if (off < 0 || off >= U16_MAX)
return false;
if (off % size != 0)
return false;
return true;
}
BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size)
{
switch (cmd) {
case BPF_MAP_CREATE:
case BPF_MAP_DELETE_ELEM:
case BPF_MAP_UPDATE_ELEM:
case BPF_MAP_FREEZE:
case BPF_MAP_GET_FD_BY_ID:
case BPF_PROG_LOAD:
case BPF_BTF_LOAD:
case BPF_LINK_CREATE:
case BPF_RAW_TRACEPOINT_OPEN:
break;
default:
return -EINVAL;
}
return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size);
}
/* To shut up -Wmissing-prototypes.
* This function is used by the kernel light skeleton
* to load bpf programs when modules are loaded or during kernel boot.
* See tools/lib/bpf/skel_internal.h
*/
int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size);
int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
{
struct bpf_prog * __maybe_unused prog;
struct bpf_tramp_run_ctx __maybe_unused run_ctx;
switch (cmd) {
#ifdef CONFIG_BPF_JIT /* __bpf_prog_enter_sleepable used by trampoline and JIT */
case BPF_PROG_TEST_RUN:
if (attr->test.data_in || attr->test.data_out ||
attr->test.ctx_out || attr->test.duration ||
attr->test.repeat || attr->test.flags)
return -EINVAL;
prog = bpf_prog_get_type(attr->test.prog_fd, BPF_PROG_TYPE_SYSCALL);
if (IS_ERR(prog))
return PTR_ERR(prog);
if (attr->test.ctx_size_in < prog->aux->max_ctx_offset ||
attr->test.ctx_size_in > U16_MAX) {
bpf_prog_put(prog);
return -EINVAL;
}
run_ctx.bpf_cookie = 0;
if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
/* recursion detected */
__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
bpf_prog_put(prog);
return -EBUSY;
}
attr->test.retval = bpf_prog_run(prog, (void *) (long) attr->test.ctx_in);
__bpf_prog_exit_sleepable_recur(prog, 0 /* bpf_prog_run does runtime stats */,
&run_ctx);
bpf_prog_put(prog);
return 0;
#endif
default:
return ____bpf_sys_bpf(cmd, attr, size);
}
}
EXPORT_SYMBOL(kern_sys_bpf);
static const struct bpf_func_proto bpf_sys_bpf_proto = {
.func = bpf_sys_bpf,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
.arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY,
.arg3_type = ARG_CONST_SIZE,
};
const struct bpf_func_proto * __weak
tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
return bpf_base_func_proto(func_id, prog);
}
BPF_CALL_1(bpf_sys_close, u32, fd)
{
/* When bpf program calls this helper there should not be
* an fdget() without matching completed fdput().
* This helper is allowed in the following callchain only:
* sys_bpf->prog_test_run->bpf_prog->bpf_sys_close
*/
return close_fd(fd);
}
static const struct bpf_func_proto bpf_sys_close_proto = {
.func = bpf_sys_close,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_ANYTHING,
};
BPF_CALL_4(bpf_kallsyms_lookup_name, const char *, name, int, name_sz, int, flags, u64 *, res)
{
*res = 0;
if (flags)
return -EINVAL;
if (name_sz <= 1 || name[name_sz - 1])
return -EINVAL;
if (!bpf_dump_raw_ok(current_cred()))
return -EPERM;
*res = kallsyms_lookup_name(name);
return *res ? 0 : -ENOENT;
}
static const struct bpf_func_proto bpf_kallsyms_lookup_name_proto = {
.func = bpf_kallsyms_lookup_name,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_MEM,
.arg2_type = ARG_CONST_SIZE_OR_ZERO,
.arg3_type = ARG_ANYTHING,
.arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED,
.arg4_size = sizeof(u64),
};
static const struct bpf_func_proto *
syscall_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
{
switch (func_id) {
case BPF_FUNC_sys_bpf:
return !bpf_token_capable(prog->aux->token, CAP_PERFMON)
? NULL : &bpf_sys_bpf_proto;
case BPF_FUNC_btf_find_by_name_kind:
return &bpf_btf_find_by_name_kind_proto;
case BPF_FUNC_sys_close:
return &bpf_sys_close_proto;
case BPF_FUNC_kallsyms_lookup_name:
return &bpf_kallsyms_lookup_name_proto;
default:
return tracing_prog_func_proto(func_id, prog);
}
}
const struct bpf_verifier_ops bpf_syscall_verifier_ops = {
.get_func_proto = syscall_prog_func_proto,
.is_valid_access = syscall_prog_is_valid_access,
};
const struct bpf_prog_ops bpf_syscall_prog_ops = {
.test_run = bpf_prog_test_run_syscall,
};
#ifdef CONFIG_SYSCTL
static int bpf_stats_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct static_key *key = (struct static_key *)table->data;
static int saved_val;
int val, ret;
struct ctl_table tmp = {
.data = &val,
.maxlen = sizeof(val),
.mode = table->mode,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
};
if (write && !capable(CAP_SYS_ADMIN))
return -EPERM;
mutex_lock(&bpf_stats_enabled_mutex);
val = saved_val;
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && !ret && val != saved_val) {
if (val)
static_key_slow_inc(key);
else
static_key_slow_dec(key);
saved_val = val;
}
mutex_unlock(&bpf_stats_enabled_mutex);
return ret;
}
void __weak unpriv_ebpf_notify(int new_state)
{
}
static int bpf_unpriv_handler(const struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
int ret, unpriv_enable = *(int *)table->data;
bool locked_state = unpriv_enable == 1;
struct ctl_table tmp = *table;
if (write && !capable(CAP_SYS_ADMIN))
return -EPERM;
tmp.data = &unpriv_enable;
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
if (write && !ret) {
if (locked_state && unpriv_enable != 1)
return -EPERM;
*(int *)table->data = unpriv_enable;
}
if (write)
unpriv_ebpf_notify(unpriv_enable);
return ret;
}
static struct ctl_table bpf_syscall_table[] = {
{
.procname = "unprivileged_bpf_disabled",
.data = &sysctl_unprivileged_bpf_disabled,
.maxlen = sizeof(sysctl_unprivileged_bpf_disabled),
.mode = 0644,
.proc_handler = bpf_unpriv_handler,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_TWO,
},
{
.procname = "bpf_stats_enabled",
.data = &bpf_stats_enabled_key.key,
.mode = 0644,
.proc_handler = bpf_stats_handler,
},
};
static int __init bpf_syscall_sysctl_init(void)
{
register_sysctl_init("kernel", bpf_syscall_table);
return 0;
}
late_initcall(bpf_syscall_sysctl_init);
#endif /* CONFIG_SYSCTL */
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