forked from Minki/linux
e8d2bec045
Commita26ca7c982
("bpf: btf: Add pretty print support to the basic arraymap") and699c86d6ec
("bpf: btf: add pretty print for hash/lru_hash maps") enabled support for BTF and dumping via BPF fs for array and hash/lru map. However, both can be decoupled from each other such that regular BPF maps can be supported for attaching BTF key/value information, while not all maps necessarily need to dump via map_seq_show_elem() callback. The basic sanity check which is a prerequisite for all maps is that key/value size has to match in any case, and some maps can have extra checks via map_check_btf() callback, e.g. probing certain types or indicating no support in general. With that we can also enable retrieving BTF info for per-cpu map types and lpm. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com>
380 lines
8.5 KiB
C
380 lines
8.5 KiB
C
//SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/bpf-cgroup.h>
|
|
#include <linux/bpf.h>
|
|
#include <linux/bug.h>
|
|
#include <linux/filter.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/rbtree.h>
|
|
#include <linux/slab.h>
|
|
|
|
DEFINE_PER_CPU(void*, bpf_cgroup_storage);
|
|
|
|
#ifdef CONFIG_CGROUP_BPF
|
|
|
|
#define LOCAL_STORAGE_CREATE_FLAG_MASK \
|
|
(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
|
|
|
|
struct bpf_cgroup_storage_map {
|
|
struct bpf_map map;
|
|
|
|
spinlock_t lock;
|
|
struct bpf_prog *prog;
|
|
struct rb_root root;
|
|
struct list_head list;
|
|
};
|
|
|
|
static struct bpf_cgroup_storage_map *map_to_storage(struct bpf_map *map)
|
|
{
|
|
return container_of(map, struct bpf_cgroup_storage_map, map);
|
|
}
|
|
|
|
static int bpf_cgroup_storage_key_cmp(
|
|
const struct bpf_cgroup_storage_key *key1,
|
|
const struct bpf_cgroup_storage_key *key2)
|
|
{
|
|
if (key1->cgroup_inode_id < key2->cgroup_inode_id)
|
|
return -1;
|
|
else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
|
|
return 1;
|
|
else if (key1->attach_type < key2->attach_type)
|
|
return -1;
|
|
else if (key1->attach_type > key2->attach_type)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static struct bpf_cgroup_storage *cgroup_storage_lookup(
|
|
struct bpf_cgroup_storage_map *map, struct bpf_cgroup_storage_key *key,
|
|
bool locked)
|
|
{
|
|
struct rb_root *root = &map->root;
|
|
struct rb_node *node;
|
|
|
|
if (!locked)
|
|
spin_lock_bh(&map->lock);
|
|
|
|
node = root->rb_node;
|
|
while (node) {
|
|
struct bpf_cgroup_storage *storage;
|
|
|
|
storage = container_of(node, struct bpf_cgroup_storage, node);
|
|
|
|
switch (bpf_cgroup_storage_key_cmp(key, &storage->key)) {
|
|
case -1:
|
|
node = node->rb_left;
|
|
break;
|
|
case 1:
|
|
node = node->rb_right;
|
|
break;
|
|
default:
|
|
if (!locked)
|
|
spin_unlock_bh(&map->lock);
|
|
return storage;
|
|
}
|
|
}
|
|
|
|
if (!locked)
|
|
spin_unlock_bh(&map->lock);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
|
|
struct bpf_cgroup_storage *storage)
|
|
{
|
|
struct rb_root *root = &map->root;
|
|
struct rb_node **new = &(root->rb_node), *parent = NULL;
|
|
|
|
while (*new) {
|
|
struct bpf_cgroup_storage *this;
|
|
|
|
this = container_of(*new, struct bpf_cgroup_storage, node);
|
|
|
|
parent = *new;
|
|
switch (bpf_cgroup_storage_key_cmp(&storage->key, &this->key)) {
|
|
case -1:
|
|
new = &((*new)->rb_left);
|
|
break;
|
|
case 1:
|
|
new = &((*new)->rb_right);
|
|
break;
|
|
default:
|
|
return -EEXIST;
|
|
}
|
|
}
|
|
|
|
rb_link_node(&storage->node, parent, new);
|
|
rb_insert_color(&storage->node, root);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void *cgroup_storage_lookup_elem(struct bpf_map *_map, void *_key)
|
|
{
|
|
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
|
|
struct bpf_cgroup_storage_key *key = _key;
|
|
struct bpf_cgroup_storage *storage;
|
|
|
|
storage = cgroup_storage_lookup(map, key, false);
|
|
if (!storage)
|
|
return NULL;
|
|
|
|
return &READ_ONCE(storage->buf)->data[0];
|
|
}
|
|
|
|
static int cgroup_storage_update_elem(struct bpf_map *map, void *_key,
|
|
void *value, u64 flags)
|
|
{
|
|
struct bpf_cgroup_storage_key *key = _key;
|
|
struct bpf_cgroup_storage *storage;
|
|
struct bpf_storage_buffer *new;
|
|
|
|
if (flags & BPF_NOEXIST)
|
|
return -EINVAL;
|
|
|
|
storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
|
|
key, false);
|
|
if (!storage)
|
|
return -ENOENT;
|
|
|
|
new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
|
|
map->value_size, __GFP_ZERO | GFP_USER,
|
|
map->numa_node);
|
|
if (!new)
|
|
return -ENOMEM;
|
|
|
|
memcpy(&new->data[0], value, map->value_size);
|
|
|
|
new = xchg(&storage->buf, new);
|
|
kfree_rcu(new, rcu);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cgroup_storage_get_next_key(struct bpf_map *_map, void *_key,
|
|
void *_next_key)
|
|
{
|
|
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
|
|
struct bpf_cgroup_storage_key *key = _key;
|
|
struct bpf_cgroup_storage_key *next = _next_key;
|
|
struct bpf_cgroup_storage *storage;
|
|
|
|
spin_lock_bh(&map->lock);
|
|
|
|
if (list_empty(&map->list))
|
|
goto enoent;
|
|
|
|
if (key) {
|
|
storage = cgroup_storage_lookup(map, key, true);
|
|
if (!storage)
|
|
goto enoent;
|
|
|
|
storage = list_next_entry(storage, list);
|
|
if (!storage)
|
|
goto enoent;
|
|
} else {
|
|
storage = list_first_entry(&map->list,
|
|
struct bpf_cgroup_storage, list);
|
|
}
|
|
|
|
spin_unlock_bh(&map->lock);
|
|
next->attach_type = storage->key.attach_type;
|
|
next->cgroup_inode_id = storage->key.cgroup_inode_id;
|
|
return 0;
|
|
|
|
enoent:
|
|
spin_unlock_bh(&map->lock);
|
|
return -ENOENT;
|
|
}
|
|
|
|
static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
|
|
{
|
|
int numa_node = bpf_map_attr_numa_node(attr);
|
|
struct bpf_cgroup_storage_map *map;
|
|
|
|
if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (attr->value_size > PAGE_SIZE)
|
|
return ERR_PTR(-E2BIG);
|
|
|
|
if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK)
|
|
/* reserved bits should not be used */
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (attr->max_entries)
|
|
/* max_entries is not used and enforced to be 0 */
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
|
|
__GFP_ZERO | GFP_USER, numa_node);
|
|
if (!map)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
map->map.pages = round_up(sizeof(struct bpf_cgroup_storage_map),
|
|
PAGE_SIZE) >> PAGE_SHIFT;
|
|
|
|
/* copy mandatory map attributes */
|
|
bpf_map_init_from_attr(&map->map, attr);
|
|
|
|
spin_lock_init(&map->lock);
|
|
map->root = RB_ROOT;
|
|
INIT_LIST_HEAD(&map->list);
|
|
|
|
return &map->map;
|
|
}
|
|
|
|
static void cgroup_storage_map_free(struct bpf_map *_map)
|
|
{
|
|
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
|
|
|
|
WARN_ON(!RB_EMPTY_ROOT(&map->root));
|
|
WARN_ON(!list_empty(&map->list));
|
|
|
|
kfree(map);
|
|
}
|
|
|
|
static int cgroup_storage_delete_elem(struct bpf_map *map, void *key)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
const struct bpf_map_ops cgroup_storage_map_ops = {
|
|
.map_alloc = cgroup_storage_map_alloc,
|
|
.map_free = cgroup_storage_map_free,
|
|
.map_get_next_key = cgroup_storage_get_next_key,
|
|
.map_lookup_elem = cgroup_storage_lookup_elem,
|
|
.map_update_elem = cgroup_storage_update_elem,
|
|
.map_delete_elem = cgroup_storage_delete_elem,
|
|
.map_check_btf = map_check_no_btf,
|
|
};
|
|
|
|
int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *_map)
|
|
{
|
|
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
|
|
int ret = -EBUSY;
|
|
|
|
spin_lock_bh(&map->lock);
|
|
|
|
if (map->prog && map->prog != prog)
|
|
goto unlock;
|
|
if (prog->aux->cgroup_storage && prog->aux->cgroup_storage != _map)
|
|
goto unlock;
|
|
|
|
map->prog = prog;
|
|
prog->aux->cgroup_storage = _map;
|
|
ret = 0;
|
|
unlock:
|
|
spin_unlock_bh(&map->lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *_map)
|
|
{
|
|
struct bpf_cgroup_storage_map *map = map_to_storage(_map);
|
|
|
|
spin_lock_bh(&map->lock);
|
|
if (map->prog == prog) {
|
|
WARN_ON(prog->aux->cgroup_storage != _map);
|
|
map->prog = NULL;
|
|
prog->aux->cgroup_storage = NULL;
|
|
}
|
|
spin_unlock_bh(&map->lock);
|
|
}
|
|
|
|
struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog)
|
|
{
|
|
struct bpf_cgroup_storage *storage;
|
|
struct bpf_map *map;
|
|
u32 pages;
|
|
|
|
map = prog->aux->cgroup_storage;
|
|
if (!map)
|
|
return NULL;
|
|
|
|
pages = round_up(sizeof(struct bpf_cgroup_storage) +
|
|
sizeof(struct bpf_storage_buffer) +
|
|
map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
|
|
if (bpf_map_charge_memlock(map, pages))
|
|
return ERR_PTR(-EPERM);
|
|
|
|
storage = kmalloc_node(sizeof(struct bpf_cgroup_storage),
|
|
__GFP_ZERO | GFP_USER, map->numa_node);
|
|
if (!storage) {
|
|
bpf_map_uncharge_memlock(map, pages);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
storage->buf = kmalloc_node(sizeof(struct bpf_storage_buffer) +
|
|
map->value_size, __GFP_ZERO | GFP_USER,
|
|
map->numa_node);
|
|
if (!storage->buf) {
|
|
bpf_map_uncharge_memlock(map, pages);
|
|
kfree(storage);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
storage->map = (struct bpf_cgroup_storage_map *)map;
|
|
|
|
return storage;
|
|
}
|
|
|
|
void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
|
|
{
|
|
u32 pages;
|
|
struct bpf_map *map;
|
|
|
|
if (!storage)
|
|
return;
|
|
|
|
map = &storage->map->map;
|
|
pages = round_up(sizeof(struct bpf_cgroup_storage) +
|
|
sizeof(struct bpf_storage_buffer) +
|
|
map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
|
|
bpf_map_uncharge_memlock(map, pages);
|
|
|
|
kfree_rcu(storage->buf, rcu);
|
|
kfree_rcu(storage, rcu);
|
|
}
|
|
|
|
void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
|
|
struct cgroup *cgroup,
|
|
enum bpf_attach_type type)
|
|
{
|
|
struct bpf_cgroup_storage_map *map;
|
|
|
|
if (!storage)
|
|
return;
|
|
|
|
storage->key.attach_type = type;
|
|
storage->key.cgroup_inode_id = cgroup->kn->id.id;
|
|
|
|
map = storage->map;
|
|
|
|
spin_lock_bh(&map->lock);
|
|
WARN_ON(cgroup_storage_insert(map, storage));
|
|
list_add(&storage->list, &map->list);
|
|
spin_unlock_bh(&map->lock);
|
|
}
|
|
|
|
void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
|
|
{
|
|
struct bpf_cgroup_storage_map *map;
|
|
struct rb_root *root;
|
|
|
|
if (!storage)
|
|
return;
|
|
|
|
map = storage->map;
|
|
|
|
spin_lock_bh(&map->lock);
|
|
root = &map->root;
|
|
rb_erase(&storage->node, root);
|
|
|
|
list_del(&storage->list);
|
|
spin_unlock_bh(&map->lock);
|
|
}
|
|
|
|
#endif
|