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// 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>#include <linux/btf_ids.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 long 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) &&		     !btf_record_has_field(map->record, BPF_SPIN_LOCK)))		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, struct_size(new, data, map->value_size),				   __GFP_ZERO | GFP_NOWAIT,				   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, u64 map_flags){	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	 */	if (map_flags & BPF_F_CPU) {		cpu = map_flags >> 32;		copy_map_value(_map, value, per_cpu_ptr(storage->percpu_buf, cpu));		goto unlock;	}	size = round_up(_map->value_size, 8);	for_each_possible_cpu(cpu) {		copy_map_value_long(_map, value + off, per_cpu_ptr(storage->percpu_buf, cpu));		off += size;	}unlock:	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;	void *val;	u32 size;	int cpu, off = 0; 	if ((u32)map_flags & ~(BPF_ANY | BPF_EXIST | BPF_F_CPU | BPF_F_ALL_CPUS))		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	 */	if (map_flags & BPF_F_CPU) {		cpu = map_flags >> 32;		copy_map_value(_map, per_cpu_ptr(storage->percpu_buf, cpu), value);		goto unlock;	}	size = round_up(_map->value_size, 8);	for_each_possible_cpu(cpu) {		val = (map_flags & BPF_F_ALL_CPUS) ? value : value + off;		copy_map_value(_map, per_cpu_ptr(storage->percpu_buf, cpu), val);		off += size;	}unlock:	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 (list_entry_is_head(storage, &map->list, list_map))			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 = bpf_map_area_alloc(sizeof(struct bpf_cgroup_storage_map), 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; 	cgroup_lock(); 	list_for_each_entry_safe(storage, stmp, storages, list_map) {		bpf_cgroup_storage_unlink(storage);		bpf_cgroup_storage_free(storage);	} 	cgroup_unlock(); 	WARN_ON(!RB_EMPTY_ROOT(&map->root));	WARN_ON(!list_empty(&map->list)); 	bpf_map_area_free(map);} static long cgroup_storage_delete_elem(struct bpf_map *map, void *key){	return -EINVAL;} static int cgroup_storage_check_btf(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 {		/*		 * Key is expected to be u64, which stores the cgroup_inode_id		 */		if (!btf_type_is_i64(key_type))			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_putc(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_putc(m, '\n');		}		seq_puts(m, "}\n");	}	rcu_read_unlock();} static u64 cgroup_storage_map_usage(const struct bpf_map *map){	/* Currently the dynamically allocated elements are not counted. */	return sizeof(struct bpf_cgroup_storage_map);} BTF_ID_LIST_SINGLE(cgroup_storage_map_btf_ids, struct,		   bpf_cgroup_storage_map)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_mem_usage = cgroup_storage_map_usage,	.map_btf_id = &cgroup_storage_map_btf_ids[0],}; 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;	} 

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