Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c
index fc1605a..addd6fd 100644
--- a/kernel/bpf/local_storage.c
+++ b/kernel/bpf/local_storage.c
@@ -1,18 +1,20 @@
 //SPDX-License-Identifier: GPL-2.0
 #include <linux/bpf-cgroup.h>
 #include <linux/bpf.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>
 
-DEFINE_PER_CPU(void*, bpf_cgroup_storage);
+DEFINE_PER_CPU(struct bpf_cgroup_storage*, bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
 
 #ifdef CONFIG_CGROUP_BPF
 
 #define LOCAL_STORAGE_CREATE_FLAG_MASK					\
-	(BPF_F_NUMA_NODE | BPF_F_RDONLY | BPF_F_WRONLY)
+	(BPF_F_NUMA_NODE | BPF_F_ACCESS_MASK)
 
 struct bpf_cgroup_storage_map {
 	struct bpf_map map;
@@ -129,7 +131,14 @@
 	struct bpf_cgroup_storage *storage;
 	struct bpf_storage_buffer *new;
 
-	if (flags != BPF_ANY && flags != BPF_EXIST)
+	if (unlikely(flags & ~(BPF_F_LOCK | BPF_EXIST | BPF_NOEXIST)))
+		return -EINVAL;
+
+	if (unlikely(flags & BPF_NOEXIST))
+		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,
@@ -137,6 +146,11 @@
 	if (!storage)
 		return -ENOENT;
 
+	if (flags & BPF_F_LOCK) {
+		copy_map_value_locked(map, storage->buf->data, value, false);
+		return 0;
+	}
+
 	new = kmalloc_node(sizeof(struct bpf_storage_buffer) +
 			   map->value_size,
 			   __GFP_ZERO | GFP_ATOMIC | __GFP_NOWARN,
@@ -145,6 +159,7 @@
 		return -ENOMEM;
 
 	memcpy(&new->data[0], value, map->value_size);
+	check_and_init_map_lock(map, new->data);
 
 	new = xchg(&storage->buf, new);
 	kfree_rcu(new, rcu);
@@ -152,6 +167,71 @@
 	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_key *key = _key;
+	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_key *key = _key;
+	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)
 {
@@ -192,6 +272,8 @@
 {
 	int numa_node = bpf_map_attr_numa_node(attr);
 	struct bpf_cgroup_storage_map *map;
+	struct bpf_map_memory mem;
+	int ret;
 
 	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
 		return ERR_PTR(-EINVAL);
@@ -202,21 +284,26 @@
 	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 */
+	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);
 
+	ret = bpf_map_charge_init(&mem, sizeof(struct bpf_cgroup_storage_map));
+	if (ret < 0)
+		return ERR_PTR(ret);
+
 	map = kmalloc_node(sizeof(struct bpf_cgroup_storage_map),
 			   __GFP_ZERO | GFP_USER, numa_node);
-	if (!map)
+	if (!map) {
+		bpf_map_charge_finish(&mem);
 		return ERR_PTR(-ENOMEM);
+	}
 
-	map->map.pages = round_up(sizeof(struct bpf_cgroup_storage_map),
-				  PAGE_SIZE) >> PAGE_SHIFT;
+	bpf_map_charge_move(&map->map.memory, &mem);
 
 	/* copy mandatory map attributes */
 	bpf_map_init_from_attr(&map->map, attr);
@@ -243,6 +330,85 @@
 	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)
+{
+	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 = FIELD_SIZEOF(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 = FIELD_SIZEOF(struct bpf_cgroup_storage_key, attach_type);
+	if (!btf_member_is_reg_int(btf, key_type, m, offset, size))
+		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 = cgroup_storage_type(map);
+	struct bpf_cgroup_storage_key *key = _key;
+	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();
+}
+
 const struct bpf_map_ops cgroup_storage_map_ops = {
 	.map_alloc = cgroup_storage_map_alloc,
 	.map_free = cgroup_storage_map_free,
@@ -250,11 +416,13 @@
 	.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,
+	.map_check_btf = cgroup_storage_check_btf,
+	.map_seq_show_elem = cgroup_storage_seq_show_elem,
 };
 
 int bpf_cgroup_storage_assign(struct bpf_prog *prog, struct bpf_map *_map)
 {
+	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_map);
 	struct bpf_cgroup_storage_map *map = map_to_storage(_map);
 	int ret = -EBUSY;
 
@@ -262,11 +430,12 @@
 
 	if (map->prog && map->prog != prog)
 		goto unlock;
-	if (prog->aux->cgroup_storage && prog->aux->cgroup_storage != _map)
+	if (prog->aux->cgroup_storage[stype] &&
+	    prog->aux->cgroup_storage[stype] != _map)
 		goto unlock;
 
 	map->prog = prog;
-	prog->aux->cgroup_storage = _map;
+	prog->aux->cgroup_storage[stype] = _map;
 	ret = 0;
 unlock:
 	spin_unlock_bh(&map->lock);
@@ -276,70 +445,118 @@
 
 void bpf_cgroup_storage_release(struct bpf_prog *prog, struct bpf_map *_map)
 {
+	enum bpf_cgroup_storage_type stype = cgroup_storage_type(_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);
+		WARN_ON(prog->aux->cgroup_storage[stype] != _map);
 		map->prog = NULL;
-		prog->aux->cgroup_storage = NULL;
+		prog->aux->cgroup_storage[stype] = NULL;
 	}
 	spin_unlock_bh(&map->lock);
 }
 
-struct bpf_cgroup_storage *bpf_cgroup_storage_alloc(struct bpf_prog *prog)
+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)
 {
 	struct bpf_cgroup_storage *storage;
 	struct bpf_map *map;
+	gfp_t flags;
+	size_t size;
 	u32 pages;
 
-	map = prog->aux->cgroup_storage;
+	map = prog->aux->cgroup_storage[stype];
 	if (!map)
 		return NULL;
 
-	pages = round_up(sizeof(struct bpf_cgroup_storage) +
-			 sizeof(struct bpf_storage_buffer) +
-			 map->value_size, PAGE_SIZE) >> PAGE_SHIFT;
+	size = bpf_cgroup_storage_calculate_size(map, &pages);
+
 	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);
-	}
+	if (!storage)
+		goto 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);
+	flags = __GFP_ZERO | GFP_USER;
+
+	if (stype == BPF_CGROUP_STORAGE_SHARED) {
+		storage->buf = kmalloc_node(size, flags, map->numa_node);
+		if (!storage->buf)
+			goto enomem;
+		check_and_init_map_lock(map, storage->buf->data);
+	} else {
+		storage->percpu_buf = __alloc_percpu_gfp(size, 8, flags);
+		if (!storage->percpu_buf)
+			goto enomem;
 	}
 
 	storage->map = (struct bpf_cgroup_storage_map *)map;
 
 	return storage;
+
+enomem:
+	bpf_map_uncharge_memlock(map, pages);
+	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)
 {
-	u32 pages;
+	enum bpf_cgroup_storage_type stype;
 	struct bpf_map *map;
+	u32 pages;
 
 	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_cgroup_storage_calculate_size(map, &pages);
 	bpf_map_uncharge_memlock(map, pages);
 
-	kfree_rcu(storage->buf, rcu);
-	kfree_rcu(storage, rcu);
+	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,