[mirror_ubuntu-jammy-kernel.git] / kernel / bpf / local_storage.c

//SPDX-License-Identifier: GPL-2.0
#include <linux/bpf-cgroup.h>
#include <linux/bpf.h>
#include <linux/bpf_local_storage.h>
#include <linux/btf.h>
#include <linux/bug.h>
#include <linux/filter.h>
#include <linux/mm.h>
#include <linux/rbtree.h>
#include <linux/slab.h>
#include <uapi/linux/btf.h>

#ifdef CONFIG_CGROUP_BPF

#include "../cgroup/cgroup-internal.h"

#define LOCAL_STORAGE_CREATE_FLAG_MASK					\
	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)

struct bpf_cgroup_storage_map {
	struct bpf_map map;

	spinlock_t lock;
	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 bool attach_type_isolated(const struct bpf_map *map)
{
	return map->key_size == sizeof(struct bpf_cgroup_storage_key);
}

static int bpf_cgroup_storage_key_cmp(const struct bpf_cgroup_storage_map *map,
				      const void *_key1, const void *_key2)
{
	if (attach_type_isolated(&map->map)) {
		const struct bpf_cgroup_storage_key *key1 = _key1;
		const struct bpf_cgroup_storage_key *key2 = _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;
	} else {
		const __u64 *cgroup_inode_id1 = _key1;
		const __u64 *cgroup_inode_id2 = _key2;

		if (*cgroup_inode_id1 < *cgroup_inode_id2)
			return -1;
		else if (*cgroup_inode_id1 > *cgroup_inode_id2)
			return 1;
	}
	return 0;
}

struct bpf_cgroup_storage *
cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
		      void *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(map, 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(map, &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 *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 *storage;
	struct bpf_storage_buffer *new;

	if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST)))
		return -EINVAL;

	if (unlikely((flags & BPF_F_LOCK) &&
		     !map_value_has_spin_lock(map)))
		return -EINVAL;

	storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
					key, false);
	if (!storage)
		return -ENOENT;

	if (flags & BPF_F_LOCK) {
		copy_map_value_locked(map, storage->buf->data, value, false);
		return 0;
	}

	new = bpf_map_kmalloc_node(map, sizeof(struct bpf_storage_buffer) +
				   map->value_size,
				   __GFP_ZERO | GFP_ATOMIC | __GFP_NOWARN,
				   map->numa_node);
	if (!new)
		return -ENOMEM;

	memcpy(&new->data[0], value, map->value_size);
	check_and_init_map_value(map, new->data);

	new = xchg(&storage->buf, new);
	kfree_rcu(new, rcu);

	return 0;
}

int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key,
				   void *value)
{
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	struct bpf_cgroup_storage *storage;
	int cpu, off = 0;
	u32 size;

	rcu_read_lock();
	storage = cgroup_storage_lookup(map, key, false);
	if (!storage) {
		rcu_read_unlock();
		return -ENOENT;
	}

	/* per_cpu areas are zero-filled and bpf programs can only
	 * access 'value_size' of them, so copying rounded areas
	 * will not leak any kernel data
	 */
	size = round_up(_map->value_size, 8);
	for_each_possible_cpu(cpu) {
		bpf_long_memcpy(value + off,
				per_cpu_ptr(storage->percpu_buf, cpu), size);
		off += size;
	}
	rcu_read_unlock();
	return 0;
}

int bpf_percpu_cgroup_storage_update(struct bpf_map *_map, void *key,
				     void *value, u64 map_flags)
{
	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
	struct bpf_cgroup_storage *storage;
	int cpu, off = 0;
	u32 size;

	if (map_flags != BPF_ANY && map_flags != BPF_EXIST)
		return -EINVAL;

	rcu_read_lock();
	storage = cgroup_storage_lookup(map, key, false);
	if (!storage) {
		rcu_read_unlock();
		return -ENOENT;
	}

	/* the user space will provide round_up(value_size, 8) bytes that
	 * will be copied into per-cpu area. bpf programs can only access
	 * value_size of it. During lookup the same extra bytes will be
	 * returned or zeros which were zero-filled by percpu_alloc,
	 * so no kernel data leaks possible
	 */
	size = round_up(_map->value_size, 8);
	for_each_possible_cpu(cpu) {
		bpf_long_memcpy(per_cpu_ptr(storage->percpu_buf, cpu),
				value + off, size);
		off += size;
	}
	rcu_read_unlock();
	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 *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_map);
		if (!storage)
			goto enoent;
	} else {
		storage = list_first_entry(&map->list,
					 struct bpf_cgroup_storage, list_map);
	}

	spin_unlock_bh(&map->lock);

	if (attach_type_isolated(&map->map)) {
		struct bpf_cgroup_storage_key *next = _next_key;
		*next = storage->key;
	} else {
		__u64 *next = _next_key;
		*next = 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)
{
	__u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
	int numa_node = bpf_map_attr_numa_node(attr);
	struct bpf_cgroup_storage_map *map;

	/* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
	 * is the same as other local storages.
	 */
	if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
		max_value_size = min_t(__u32, max_value_size,
				       PCPU_MIN_UNIT_SIZE);

	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
	    attr->key_size != sizeof(__u64))
		return ERR_PTR(-EINVAL);

	if (attr->value_size == 0)
		return ERR_PTR(-EINVAL);

	if (attr->value_size > max_value_size)
		return ERR_PTR(-E2BIG);

	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK ||
	    !bpf_map_flags_access_ok(attr->map_flags))
		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 | __GFP_ACCOUNT, numa_node);
	if (!map)
		return ERR_PTR(-ENOMEM);

	/* 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);
	struct list_head *storages = &map->list;
	struct bpf_cgroup_storage *storage, *stmp;

	mutex_lock(&cgroup_mutex);

	list_for_each_entry_safe(storage, stmp, storages, list_map) {
		bpf_cgroup_storage_unlink(storage);
		bpf_cgroup_storage_free(storage);
	}

	mutex_unlock(&cgroup_mutex);

	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;
}

static int cgroup_storage_check_btf(const struct bpf_map *map,
				    const struct btf *btf,
				    const struct btf_type *key_type,
				    const struct btf_type *value_type)
{
	if (attach_type_isolated(map)) {
		struct btf_member *m;
		u32 offset, size;

		/* Key is expected to be of struct bpf_cgroup_storage_key type,
		 * which is:
		 * struct bpf_cgroup_storage_key {
		 *	__u64	cgroup_inode_id;
		 *	__u32	attach_type;
		 * };
		 */

		/*
		 * Key_type must be a structure with two fields.
		 */
		if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT ||
		    BTF_INFO_VLEN(key_type->info) != 2)
			return -EINVAL;

		/*
		 * The first field must be a 64 bit integer at 0 offset.
		 */
		m = (struct btf_member *)(key_type + 1);
		size = sizeof_field(struct bpf_cgroup_storage_key, cgroup_inode_id);
		if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
			return -EINVAL;

		/*
		 * The second field must be a 32 bit integer at 64 bit offset.
		 */
		m++;
		offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
		size = sizeof_field(struct bpf_cgroup_storage_key, attach_type);
		if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
			return -EINVAL;
	} else {
		u32 int_data;

		/*
		 * Key is expected to be u64, which stores the cgroup_inode_id
		 */

		if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
			return -EINVAL;

		int_data = *(u32 *)(key_type + 1);
		if (BTF_INT_BITS(int_data) != 64 || BTF_INT_OFFSET(int_data))
			return -EINVAL;
	}

	return 0;
}

static void cgroup_storage_seq_show_elem(struct bpf_map *map, void *key,
					 struct seq_file *m)
{
	enum bpf_cgroup_storage_type stype;
	struct bpf_cgroup_storage *storage;
	int cpu;

	rcu_read_lock();
	storage = cgroup_storage_lookup(map_to_storage(map), key, false);
	if (!storage) {
		rcu_read_unlock();
		return;
	}

	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
	stype = cgroup_storage_type(map);
	if (stype == BPF_CGROUP_STORAGE_SHARED) {
		seq_puts(m, ": ");
		btf_type_seq_show(map->btf, map->btf_value_type_id,
				  &READ_ONCE(storage->buf)->data[0], m);
		seq_puts(m, "\n");
	} else {
		seq_puts(m, ": {\n");
		for_each_possible_cpu(cpu) {
			seq_printf(m, "\tcpu%d: ", cpu);
			btf_type_seq_show(map->btf, map->btf_value_type_id,
					  per_cpu_ptr(storage->percpu_buf, cpu),
					  m);
			seq_puts(m, "\n");
		}
		seq_puts(m, "}\n");
	}
	rcu_read_unlock();
}

static int cgroup_storage_map_btf_id;
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 = cgroup_storage_check_btf,
	.map_seq_show_elem = cgroup_storage_seq_show_elem,
	.map_btf_name = "bpf_cgroup_storage_map",
	.map_btf_id = &cgroup_storage_map_btf_id,
};

int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *_map)
{
	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);

	if (aux->cgroup_storage[stype] &&
	    aux->cgroup_storage[stype] != _map)
		return -EBUSY;

	aux->cgroup_storage[stype] = _map;
	return 0;
}

static size_t bpf_cgroup_storage_calculate_size(struct bpf_map *map, u32 *pages)
{
	size_t size;

	if (cgroup_storage_type(map) == BPF_CGROUP_STORAGE_SHARED) {
		size = sizeof(struct bpf_storage_buffer) + map->value_size;
		*pages = round_up(sizeof(struct bpf_cgroup_storage) + size,
				  PAGE_SIZE) >> PAGE_SHIFT;
	} else {
		size = map->value_size;
		*pages = round_up(round_up(size, 8) * num_possible_cpus(),
				  PAGE_SIZE) >> PAGE_SHIFT;
	}

	return size;
}

struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog,
					enum bpf_cgroup_storage_type stype)
{
	const gfp_t gfp = __GFP_ZERO | GFP_USER;
	struct bpf_cgroup_storage *storage;
	struct bpf_map *map;
	size_t size;
	u32 pages;

	map = prog->aux->cgroup_storage[stype];
	if (!map)
		return NULL;

	size = bpf_cgroup_storage_calculate_size(map, &pages);

	storage = bpf_map_kmalloc_node(map, sizeof(struct bpf_cgroup_storage),
				       gfp, map->numa_node);
	if (!storage)
		goto enomem;

	if (stype == BPF_CGROUP_STORAGE_SHARED) {
		storage->buf = bpf_map_kmalloc_node(map, size, gfp,
						    map->numa_node);
		if (!storage->buf)
			goto enomem;
		check_and_init_map_value(map, storage->buf->data);
	} else {
		storage->percpu_buf = bpf_map_alloc_percpu(map, size, 8, gfp);
		if (!storage->percpu_buf)
			goto enomem;
	}

	storage->map = (struct bpf_cgroup_storage_map *)map;

	return storage;

enomem:
	kfree(storage);
	return ERR_PTR(-ENOMEM);
}

static void free_shared_cgroup_storage_rcu(struct rcu_head *rcu)
{
	struct bpf_cgroup_storage *storage =
		container_of(rcu, struct bpf_cgroup_storage, rcu);

	kfree(storage->buf);
	kfree(storage);
}

static void free_percpu_cgroup_storage_rcu(struct rcu_head *rcu)
{
	struct bpf_cgroup_storage *storage =
		container_of(rcu, struct bpf_cgroup_storage, rcu);

	free_percpu(storage->percpu_buf);
	kfree(storage);
}

void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
{
	enum bpf_cgroup_storage_type stype;
	struct bpf_map *map;

	if (!storage)
		return;

	map = &storage->map->map;
	stype = cgroup_storage_type(map);
	if (stype == BPF_CGROUP_STORAGE_SHARED)
		call_rcu(&storage->rcu, free_shared_cgroup_storage_rcu);
	else
		call_rcu(&storage->rcu, free_percpu_cgroup_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_id(cgroup);

	map = storage->map;

	spin_lock_bh(&map->lock);
	WARN_ON(cgroup_storage_insert(map, storage));
	list_add(&storage->list_map, &map->list);
	list_add(&storage->list_cg, &cgroup->bpf.storages);
	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_map);
	list_del(&storage->list_cg);
	spin_unlock_bh(&map->lock);
}

#endif
Commit	Line	Data
de9cbbaa RG	1	//SPDX-License-Identifier: GPL-2.0
	2	#include <linux/bpf-cgroup.h>
	3	#include <linux/bpf.h>
33b57e0c	4	#include <linux/bpf_local_storage.h>
9a1126b6	5	#include <linux/btf.h>
de9cbbaa RG	6	#include <linux/bug.h>
	7	#include <linux/filter.h>
	8	#include <linux/mm.h>
	9	#include <linux/rbtree.h>
	10	#include <linux/slab.h>
9a1126b6	11	#include <uapi/linux/btf.h>
de9cbbaa RG	12
	13	#ifdef CONFIG_CGROUP_BPF
	14
dfcdf0e9 YZ	15	#include "../cgroup/cgroup-internal.h"
dfcdf0e9 YZ	16
de9cbbaa	17	#define LOCAL_STORAGE_CREATE_FLAG_MASK \
591fe988	18	(BPF_F_NUMA_NODE \| BPF_F_ACCESS_MASK)
de9cbbaa RG	19
	20	struct bpf_cgroup_storage_map {
	21	struct bpf_map map;
	22
	23	spinlock_t lock;
de9cbbaa RG	24	struct rb_root root;
	25	struct list_head list;
	26	};
	27
	28	static struct bpf_cgroup_storage_map map_to_storage(struct bpf_map map)
	29	{
	30	return container_of(map, struct bpf_cgroup_storage_map, map);
	31	}
	32
7d9c3427	33	static bool attach_type_isolated(const struct bpf_map *map)
de9cbbaa	34	{
7d9c3427 YZ	35	return map->key_size == sizeof(struct bpf_cgroup_storage_key);
	36	}
	37
	38	static int bpf_cgroup_storage_key_cmp(const struct bpf_cgroup_storage_map *map,
	39	const void _key1, const void _key2)
	40	{
	41	if (attach_type_isolated(&map->map)) {
	42	const struct bpf_cgroup_storage_key *key1 = _key1;
	43	const struct bpf_cgroup_storage_key *key2 = _key2;
	44
	45	if (key1->cgroup_inode_id < key2->cgroup_inode_id)
	46	return -1;
	47	else if (key1->cgroup_inode_id > key2->cgroup_inode_id)
	48	return 1;
	49	else if (key1->attach_type < key2->attach_type)
	50	return -1;
	51	else if (key1->attach_type > key2->attach_type)
	52	return 1;
	53	} else {
	54	const __u64 *cgroup_inode_id1 = _key1;
	55	const __u64 *cgroup_inode_id2 = _key2;
	56
	57	if (cgroup_inode_id1 < cgroup_inode_id2)
	58	return -1;
	59	else if (cgroup_inode_id1 > cgroup_inode_id2)
	60	return 1;
	61	}
de9cbbaa RG	62	return 0;
	63	}
	64
7d9c3427 YZ	65	struct bpf_cgroup_storage *
	66	cgroup_storage_lookup(struct bpf_cgroup_storage_map *map,
	67	void *key, bool locked)
de9cbbaa RG	68	{
	69	struct rb_root *root = &map->root;
	70	struct rb_node *node;
	71
	72	if (!locked)
	73	spin_lock_bh(&map->lock);
	74
	75	node = root->rb_node;
	76	while (node) {
	77	struct bpf_cgroup_storage *storage;
	78
	79	storage = container_of(node, struct bpf_cgroup_storage, node);
	80
7d9c3427	81	switch (bpf_cgroup_storage_key_cmp(map, key, &storage->key)) {
de9cbbaa RG	82	case -1:
	83	node = node->rb_left;
	84	break;
	85	case 1:
	86	node = node->rb_right;
	87	break;
	88	default:
	89	if (!locked)
	90	spin_unlock_bh(&map->lock);
	91	return storage;
	92	}
	93	}
	94
	95	if (!locked)
	96	spin_unlock_bh(&map->lock);
	97
	98	return NULL;
	99	}
	100
	101	static int cgroup_storage_insert(struct bpf_cgroup_storage_map *map,
	102	struct bpf_cgroup_storage *storage)
	103	{
	104	struct rb_root *root = &map->root;
	105	struct rb_node *new = &(root->rb_node), parent = NULL;
	106
	107	while (*new) {
	108	struct bpf_cgroup_storage *this;
	109
	110	this = container_of(*new, struct bpf_cgroup_storage, node);
	111
	112	parent = *new;
7d9c3427	113	switch (bpf_cgroup_storage_key_cmp(map, &storage->key, &this->key)) {
de9cbbaa RG	114	case -1:
	115	new = &((*new)->rb_left);
	116	break;
	117	case 1:
	118	new = &((*new)->rb_right);
	119	break;
	120	default:
	121	return -EEXIST;
	122	}
	123	}
	124
	125	rb_link_node(&storage->node, parent, new);
	126	rb_insert_color(&storage->node, root);
	127
	128	return 0;
	129	}
	130
7d9c3427	131	static void cgroup_storage_lookup_elem(struct bpf_map _map, void *key)
de9cbbaa RG	132	{
de9cbbaa RG	133	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
de9cbbaa RG	134	struct bpf_cgroup_storage *storage;
	135
	136	storage = cgroup_storage_lookup(map, key, false);
	137	if (!storage)
	138	return NULL;
	139
	140	return &READ_ONCE(storage->buf)->data[0];
	141	}
	142
7d9c3427	143	static int cgroup_storage_update_elem(struct bpf_map map, void key,
de9cbbaa RG	144	void *value, u64 flags)
de9cbbaa RG	145	{
de9cbbaa RG	146	struct bpf_cgroup_storage *storage;
	147	struct bpf_storage_buffer *new;
	148
7d9c3427	149	if (unlikely(flags & ~(BPF_F_LOCK \| BPF_EXIST)))
96049f3a AS	150	return -EINVAL;
	151
	152	if (unlikely((flags & BPF_F_LOCK) &&
	153	!map_value_has_spin_lock(map)))
de9cbbaa RG	154	return -EINVAL;
	155
	156	storage = cgroup_storage_lookup((struct bpf_cgroup_storage_map *)map,
	157	key, false);
	158	if (!storage)
	159	return -ENOENT;
	160
96049f3a AS	161	if (flags & BPF_F_LOCK) {
	162	copy_map_value_locked(map, storage->buf->data, value, false);
	163	return 0;
	164	}
	165
3a61c7c5 RG	166	new = bpf_map_kmalloc_node(map, sizeof(struct bpf_storage_buffer) +
	167	map->value_size,
	168	__GFP_ZERO \| GFP_ATOMIC \| __GFP_NOWARN,
	169	map->numa_node);
de9cbbaa RG	170	if (!new)
	171	return -ENOMEM;
	172
	173	memcpy(&new->data[0], value, map->value_size);
68134668	174	check_and_init_map_value(map, new->data);
de9cbbaa RG	175
	176	new = xchg(&storage->buf, new);
	177	kfree_rcu(new, rcu);
	178
	179	return 0;
	180	}
	181
7d9c3427	182	int bpf_percpu_cgroup_storage_copy(struct bpf_map _map, void key,
b741f163 RG	183	void *value)
	184	{
	185	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
b741f163 RG	186	struct bpf_cgroup_storage *storage;
	187	int cpu, off = 0;
	188	u32 size;
	189
	190	rcu_read_lock();
	191	storage = cgroup_storage_lookup(map, key, false);
	192	if (!storage) {
	193	rcu_read_unlock();
	194	return -ENOENT;
	195	}
	196
	197	/* per_cpu areas are zero-filled and bpf programs can only
	198	* access 'value_size' of them, so copying rounded areas
	199	* will not leak any kernel data
	200	*/
	201	size = round_up(_map->value_size, 8);
	202	for_each_possible_cpu(cpu) {
	203	bpf_long_memcpy(value + off,
	204	per_cpu_ptr(storage->percpu_buf, cpu), size);
	205	off += size;
	206	}
	207	rcu_read_unlock();
	208	return 0;
	209	}
	210
7d9c3427	211	int bpf_percpu_cgroup_storage_update(struct bpf_map _map, void key,
b741f163 RG	212	void *value, u64 map_flags)
	213	{
	214	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
b741f163 RG	215	struct bpf_cgroup_storage *storage;
	216	int cpu, off = 0;
	217	u32 size;
	218
	219	if (map_flags != BPF_ANY && map_flags != BPF_EXIST)
	220	return -EINVAL;
	221
	222	rcu_read_lock();
	223	storage = cgroup_storage_lookup(map, key, false);
	224	if (!storage) {
	225	rcu_read_unlock();
	226	return -ENOENT;
	227	}
	228
	229	/* the user space will provide round_up(value_size, 8) bytes that
	230	* will be copied into per-cpu area. bpf programs can only access
	231	* value_size of it. During lookup the same extra bytes will be
	232	* returned or zeros which were zero-filled by percpu_alloc,
	233	* so no kernel data leaks possible
	234	*/
	235	size = round_up(_map->value_size, 8);
	236	for_each_possible_cpu(cpu) {
	237	bpf_long_memcpy(per_cpu_ptr(storage->percpu_buf, cpu),
	238	value + off, size);
	239	off += size;
	240	}
	241	rcu_read_unlock();
	242	return 0;
	243	}
	244
7d9c3427	245	static int cgroup_storage_get_next_key(struct bpf_map _map, void key,
de9cbbaa RG	246	void *_next_key)
	247	{
	248	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
de9cbbaa RG	249	struct bpf_cgroup_storage *storage;
	250
	251	spin_lock_bh(&map->lock);
	252
	253	if (list_empty(&map->list))
	254	goto enoent;
	255
	256	if (key) {
	257	storage = cgroup_storage_lookup(map, key, true);
	258	if (!storage)
	259	goto enoent;
	260
7d9c3427	261	storage = list_next_entry(storage, list_map);
de9cbbaa RG	262	if (!storage)
	263	goto enoent;
	264	} else {
	265	storage = list_first_entry(&map->list,
7d9c3427	266	struct bpf_cgroup_storage, list_map);
de9cbbaa RG	267	}
	268
	269	spin_unlock_bh(&map->lock);
7d9c3427 YZ	270
	271	if (attach_type_isolated(&map->map)) {
	272	struct bpf_cgroup_storage_key *next = _next_key;
	273	*next = storage->key;
	274	} else {
	275	__u64 *next = _next_key;
	276	*next = storage->key.cgroup_inode_id;
	277	}
de9cbbaa RG	278	return 0;
	279
	280	enoent:
	281	spin_unlock_bh(&map->lock);
	282	return -ENOENT;
	283	}
	284
	285	static struct bpf_map cgroup_storage_map_alloc(union bpf_attr attr)
	286	{
33b57e0c	287	__u32 max_value_size = BPF_LOCAL_STORAGE_MAX_VALUE_SIZE;
de9cbbaa RG	288	int numa_node = bpf_map_attr_numa_node(attr);
	289	struct bpf_cgroup_storage_map *map;
	290
33b57e0c SF	291	/* percpu is bound by PCPU_MIN_UNIT_SIZE, non-percu
	292	* is the same as other local storages.
	293	*/
	294	if (attr->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE)
	295	max_value_size = min_t(__u32, max_value_size,
	296	PCPU_MIN_UNIT_SIZE);
	297
7d9c3427 YZ	298	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key) &&
7d9c3427 YZ	299	attr->key_size != sizeof(__u64))
de9cbbaa RG	300	return ERR_PTR(-EINVAL);
de9cbbaa RG	301
b0584ea6 RG	302	if (attr->value_size == 0)
	303	return ERR_PTR(-EINVAL);
	304
33b57e0c	305	if (attr->value_size > max_value_size)
de9cbbaa RG	306	return ERR_PTR(-E2BIG);
de9cbbaa RG	307
591fe988 DB	308	if (attr->map_flags & ~LOCAL_STORAGE_CREATE_FLAG_MASK \|\|
591fe988 DB	309	!bpf_map_flags_access_ok(attr->map_flags))
de9cbbaa RG	310	return ERR_PTR(-EINVAL);
	311
	312	if (attr->max_entries)
	313	/* max_entries is not used and enforced to be 0 */
	314	return ERR_PTR(-EINVAL);
	315
	316	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
3a61c7c5	317	__GFP_ZERO \| GFP_USER \| __GFP_ACCOUNT, numa_node);
087b0d39	318	if (!map)
de9cbbaa	319	return ERR_PTR(-ENOMEM);
de9cbbaa RG	320
	321	/* copy mandatory map attributes */
	322	bpf_map_init_from_attr(&map->map, attr);
	323
	324	spin_lock_init(&map->lock);
	325	map->root = RB_ROOT;
	326	INIT_LIST_HEAD(&map->list);
	327
	328	return &map->map;
	329	}
	330
	331	static void cgroup_storage_map_free(struct bpf_map *_map)
	332	{
	333	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
7d9c3427 YZ	334	struct list_head *storages = &map->list;
	335	struct bpf_cgroup_storage storage, stmp;
	336
	337	mutex_lock(&cgroup_mutex);
	338
	339	list_for_each_entry_safe(storage, stmp, storages, list_map) {
	340	bpf_cgroup_storage_unlink(storage);
	341	bpf_cgroup_storage_free(storage);
	342	}
	343
	344	mutex_unlock(&cgroup_mutex);
de9cbbaa RG	345
	346	WARN_ON(!RB_EMPTY_ROOT(&map->root));
	347	WARN_ON(!list_empty(&map->list));
	348
	349	kfree(map);
	350	}
	351
	352	static int cgroup_storage_delete_elem(struct bpf_map map, void key)
	353	{
	354	return -EINVAL;
	355	}
	356
9a1126b6 RG	357	static int cgroup_storage_check_btf(const struct bpf_map *map,
	358	const struct btf *btf,
	359	const struct btf_type *key_type,
	360	const struct btf_type *value_type)
	361	{
7d9c3427 YZ	362	if (attach_type_isolated(map)) {
	363	struct btf_member *m;
	364	u32 offset, size;
	365
	366	/* Key is expected to be of struct bpf_cgroup_storage_key type,
	367	* which is:
	368	* struct bpf_cgroup_storage_key {
	369	* __u64 cgroup_inode_id;
	370	* __u32 attach_type;
	371	* };
	372	*/
	373
	374	/*
	375	* Key_type must be a structure with two fields.
	376	*/
	377	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_STRUCT \|\|
	378	BTF_INFO_VLEN(key_type->info) != 2)
	379	return -EINVAL;
	380
	381	/*
	382	* The first field must be a 64 bit integer at 0 offset.
	383	*/
	384	m = (struct btf_member *)(key_type + 1);
	385	size = sizeof_field(struct bpf_cgroup_storage_key, cgroup_inode_id);
	386	if (!btf_member_is_reg_int(btf, key_type, m, 0, size))
	387	return -EINVAL;
	388
	389	/*
	390	* The second field must be a 32 bit integer at 64 bit offset.
	391	*/
	392	m++;
	393	offset = offsetof(struct bpf_cgroup_storage_key, attach_type);
	394	size = sizeof_field(struct bpf_cgroup_storage_key, attach_type);
	395	if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
	396	return -EINVAL;
	397	} else {
	398	u32 int_data;
9a1126b6	399
7d9c3427 YZ	400	/*
	401	* Key is expected to be u64, which stores the cgroup_inode_id
	402	*/
9a1126b6	403
7d9c3427 YZ	404	if (BTF_INFO_KIND(key_type->info) != BTF_KIND_INT)
7d9c3427 YZ	405	return -EINVAL;
9a1126b6	406
7d9c3427 YZ	407	int_data = (u32 )(key_type + 1);
	408	if (BTF_INT_BITS(int_data) != 64 \|\| BTF_INT_OFFSET(int_data))
	409	return -EINVAL;
	410	}
9a1126b6 RG	411
	412	return 0;
	413	}
	414
7d9c3427	415	static void cgroup_storage_seq_show_elem(struct bpf_map map, void key,
9a1126b6 RG	416	struct seq_file *m)
9a1126b6 RG	417	{
724f17b7	418	enum bpf_cgroup_storage_type stype;
9a1126b6 RG	419	struct bpf_cgroup_storage *storage;
	420	int cpu;
	421
	422	rcu_read_lock();
	423	storage = cgroup_storage_lookup(map_to_storage(map), key, false);
	424	if (!storage) {
	425	rcu_read_unlock();
	426	return;
	427	}
	428
	429	btf_type_seq_show(map->btf, map->btf_key_type_id, key, m);
	430	stype = cgroup_storage_type(map);
	431	if (stype == BPF_CGROUP_STORAGE_SHARED) {
	432	seq_puts(m, ": ");
	433	btf_type_seq_show(map->btf, map->btf_value_type_id,
	434	&READ_ONCE(storage->buf)->data[0], m);
	435	seq_puts(m, "\n");
	436	} else {
	437	seq_puts(m, ": {\n");
	438	for_each_possible_cpu(cpu) {
	439	seq_printf(m, "\tcpu%d: ", cpu);
	440	btf_type_seq_show(map->btf, map->btf_value_type_id,
	441	per_cpu_ptr(storage->percpu_buf, cpu),
	442	m);
	443	seq_puts(m, "\n");
	444	}
	445	seq_puts(m, "}\n");
	446	}
	447	rcu_read_unlock();
	448	}
	449
2872e9ac	450	static int cgroup_storage_map_btf_id;
de9cbbaa RG	451	const struct bpf_map_ops cgroup_storage_map_ops = {
	452	.map_alloc = cgroup_storage_map_alloc,
	453	.map_free = cgroup_storage_map_free,
	454	.map_get_next_key = cgroup_storage_get_next_key,
	455	.map_lookup_elem = cgroup_storage_lookup_elem,
	456	.map_update_elem = cgroup_storage_update_elem,
	457	.map_delete_elem = cgroup_storage_delete_elem,
9a1126b6 RG	458	.map_check_btf = cgroup_storage_check_btf,
9a1126b6 RG	459	.map_seq_show_elem = cgroup_storage_seq_show_elem,
2872e9ac AI	460	.map_btf_name = "bpf_cgroup_storage_map",
2872e9ac AI	461	.map_btf_id = &cgroup_storage_map_btf_id,
de9cbbaa RG	462	};
de9cbbaa RG	463
e4730423	464	int bpf_cgroup_storage_assign(struct bpf_prog_aux aux, struct bpf_map _map)
de9cbbaa	465	{
8bad74f9	466	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
de9cbbaa	467
e4730423 DB	468	if (aux->cgroup_storage[stype] &&
e4730423 DB	469	aux->cgroup_storage[stype] != _map)
7d9c3427	470	return -EBUSY;
de9cbbaa	471
e4730423	472	aux->cgroup_storage[stype] = _map;
7d9c3427	473	return 0;
de9cbbaa RG	474	}
de9cbbaa RG	475
b741f163 RG	476	static size_t bpf_cgroup_storage_calculate_size(struct bpf_map map, u32 pages)
	477	{
	478	size_t size;
	479
	480	if (cgroup_storage_type(map) == BPF_CGROUP_STORAGE_SHARED) {
	481	size = sizeof(struct bpf_storage_buffer) + map->value_size;
	482	*pages = round_up(sizeof(struct bpf_cgroup_storage) + size,
	483	PAGE_SIZE) >> PAGE_SHIFT;
	484	} else {
	485	size = map->value_size;
	486	pages = round_up(round_up(size, 8) num_possible_cpus(),
	487	PAGE_SIZE) >> PAGE_SHIFT;
	488	}
	489
	490	return size;
	491	}
	492
8bad74f9 RG	493	struct bpf_cgroup_storage bpf_cgroup_storage_alloc(struct bpf_prog prog,
8bad74f9 RG	494	enum bpf_cgroup_storage_type stype)
de9cbbaa	495	{
3a61c7c5	496	const gfp_t gfp = __GFP_ZERO \| GFP_USER;
de9cbbaa RG	497	struct bpf_cgroup_storage *storage;
de9cbbaa RG	498	struct bpf_map *map;
b741f163	499	size_t size;
de9cbbaa RG	500	u32 pages;
de9cbbaa RG	501
8bad74f9	502	map = prog->aux->cgroup_storage[stype];
de9cbbaa RG	503	if (!map)
	504	return NULL;
	505
b741f163 RG	506	size = bpf_cgroup_storage_calculate_size(map, &pages);
b741f163 RG	507
3a61c7c5 RG	508	storage = bpf_map_kmalloc_node(map, sizeof(struct bpf_cgroup_storage),
3a61c7c5 RG	509	gfp, map->numa_node);
b741f163 RG	510	if (!storage)
b741f163 RG	511	goto enomem;
de9cbbaa	512
b741f163	513	if (stype == BPF_CGROUP_STORAGE_SHARED) {
3a61c7c5 RG	514	storage->buf = bpf_map_kmalloc_node(map, size, gfp,
3a61c7c5 RG	515	map->numa_node);
b741f163 RG	516	if (!storage->buf)
b741f163 RG	517	goto enomem;
68134668	518	check_and_init_map_value(map, storage->buf->data);
b741f163	519	} else {
3a61c7c5	520	storage->percpu_buf = bpf_map_alloc_percpu(map, size, 8, gfp);
b741f163 RG	521	if (!storage->percpu_buf)
b741f163 RG	522	goto enomem;
de9cbbaa RG	523	}
	524
	525	storage->map = (struct bpf_cgroup_storage_map *)map;
	526
	527	return storage;
b741f163 RG	528
b741f163 RG	529	enomem:
b741f163 RG	530	kfree(storage);
	531	return ERR_PTR(-ENOMEM);
	532	}
	533
	534	static void free_shared_cgroup_storage_rcu(struct rcu_head *rcu)
	535	{
	536	struct bpf_cgroup_storage *storage =
	537	container_of(rcu, struct bpf_cgroup_storage, rcu);
	538
	539	kfree(storage->buf);
	540	kfree(storage);
	541	}
	542
	543	static void free_percpu_cgroup_storage_rcu(struct rcu_head *rcu)
	544	{
	545	struct bpf_cgroup_storage *storage =
	546	container_of(rcu, struct bpf_cgroup_storage, rcu);
	547
	548	free_percpu(storage->percpu_buf);
	549	kfree(storage);
de9cbbaa RG	550	}
	551
	552	void bpf_cgroup_storage_free(struct bpf_cgroup_storage *storage)
	553	{
b741f163	554	enum bpf_cgroup_storage_type stype;
de9cbbaa RG	555	struct bpf_map *map;
	556
	557	if (!storage)
	558	return;
	559
	560	map = &storage->map->map;
b741f163 RG	561	stype = cgroup_storage_type(map);
	562	if (stype == BPF_CGROUP_STORAGE_SHARED)
	563	call_rcu(&storage->rcu, free_shared_cgroup_storage_rcu);
	564	else
	565	call_rcu(&storage->rcu, free_percpu_cgroup_storage_rcu);
de9cbbaa RG	566	}
	567
	568	void bpf_cgroup_storage_link(struct bpf_cgroup_storage *storage,
	569	struct cgroup *cgroup,
	570	enum bpf_attach_type type)
	571	{
	572	struct bpf_cgroup_storage_map *map;
	573
	574	if (!storage)
	575	return;
	576
	577	storage->key.attach_type = type;
74321038	578	storage->key.cgroup_inode_id = cgroup_id(cgroup);
de9cbbaa RG	579
	580	map = storage->map;
	581
	582	spin_lock_bh(&map->lock);
	583	WARN_ON(cgroup_storage_insert(map, storage));
7d9c3427 YZ	584	list_add(&storage->list_map, &map->list);
7d9c3427 YZ	585	list_add(&storage->list_cg, &cgroup->bpf.storages);
de9cbbaa RG	586	spin_unlock_bh(&map->lock);
	587	}
	588
	589	void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage)
	590	{
	591	struct bpf_cgroup_storage_map *map;
	592	struct rb_root *root;
	593
	594	if (!storage)
	595	return;
	596
	597	map = storage->map;
	598
	599	spin_lock_bh(&map->lock);
	600	root = &map->root;
	601	rb_erase(&storage->node, root);
	602
7d9c3427 YZ	603	list_del(&storage->list_map);
7d9c3427 YZ	604	list_del(&storage->list_cg);
de9cbbaa RG	605	spin_unlock_bh(&map->lock);
	606	}
	607
	608	#endif