bpf: move memory size checks to bpf_map_charge_init()

Most bpf map types doing similar checks and bytes to pages
conversion during memory allocation and charging.

Let's unify these checks by moving them into bpf_map_charge_init().
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

include/linux/bpf.h

@@ -652,7 +652,7 @@ void bpf_map_put_with_uref(struct bpf_map *map);
 void bpf_map_put(struct bpf_map *map);
 int bpf_map_charge_memlock(struct bpf_map *map, u32 pages);
 void bpf_map_uncharge_memlock(struct bpf_map *map, u32 pages);
-int bpf_map_charge_init(struct bpf_map_memory *mem, u32 pages);
+int bpf_map_charge_init(struct bpf_map_memory *mem, size_t size);
 void bpf_map_charge_finish(struct bpf_map_memory *mem);
 void bpf_map_charge_move(struct bpf_map_memory *dst,
 			 struct bpf_map_memory *src);

kernel/bpf/arraymap.c

@@ -117,14 +117,8 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
 
 	/* make sure there is no u32 overflow later in round_up() */
 	cost = array_size;
-	if (cost >= U32_MAX - PAGE_SIZE)
-		return ERR_PTR(-ENOMEM);
-	if (percpu) {
+	if (percpu)
 		cost += (u64)attr->max_entries * elem_size * num_possible_cpus();
-		if (cost >= U32_MAX - PAGE_SIZE)
-			return ERR_PTR(-ENOMEM);
-	}
-	cost = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
 
 	ret = bpf_map_charge_init(&mem, cost);
 	if (ret < 0)

kernel/bpf/cpumap.c

@@ -106,12 +106,9 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr)
 	/* make sure page count doesn't overflow */
 	cost = (u64) cmap->map.max_entries * sizeof(struct bpf_cpu_map_entry *);
 	cost += cpu_map_bitmap_size(attr) * num_possible_cpus();
-	if (cost >= U32_MAX - PAGE_SIZE)
-		goto free_cmap;
 
 	/* Notice returns -EPERM on if map size is larger than memlock limit */
-	ret = bpf_map_charge_init(&cmap->map.memory,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	ret = bpf_map_charge_init(&cmap->map.memory, cost);
 	if (ret) {
 		err = ret;
 		goto free_cmap;

kernel/bpf/devmap.c

@@ -108,12 +108,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
 	/* make sure page count doesn't overflow */
 	cost = (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
 	cost += dev_map_bitmap_size(attr) * num_possible_cpus();
-	if (cost >= U32_MAX - PAGE_SIZE)
-		goto free_dtab;
 
 	/* if map size is larger than memlock limit, reject it */
-	err = bpf_map_charge_init(&dtab->map.memory,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	err = bpf_map_charge_init(&dtab->map.memory, cost);
 	if (err)
 		goto free_dtab;
 

kernel/bpf/hashtab.c

@@ -360,13 +360,8 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
 	else
 	       cost += (u64) htab->elem_size * num_possible_cpus();
 
-	if (cost >= U32_MAX - PAGE_SIZE)
-		/* make sure page count doesn't overflow */
-		goto free_htab;
-
 	/* if map size is larger than memlock limit, reject it */
-	err = bpf_map_charge_init(&htab->map.memory,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	err = bpf_map_charge_init(&htab->map.memory, cost);
 	if (err)
 		goto free_htab;
 

kernel/bpf/local_storage.c

@@ -273,7 +273,6 @@ 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;
 	struct bpf_map_memory mem;
-	u32 pages;
 	int ret;
 
 	if (attr->key_size != sizeof(struct bpf_cgroup_storage_key))
@@ -293,9 +292,7 @@ static struct bpf_map *cgroup_storage_map_alloc(union bpf_attr *attr)
 		/* max_entries is not used and enforced to be 0 */
 		return ERR_PTR(-EINVAL);
 
-	pages = round_up(sizeof(struct bpf_cgroup_storage_map), PAGE_SIZE) >>
-		PAGE_SHIFT;
-	ret = bpf_map_charge_init(&mem, pages);
+	ret = bpf_map_charge_init(&mem, sizeof(struct bpf_cgroup_storage_map));
 	if (ret < 0)
 		return ERR_PTR(ret);
 

kernel/bpf/lpm_trie.c

@@ -573,13 +573,8 @@ static struct bpf_map *trie_alloc(union bpf_attr *attr)
 	cost_per_node = sizeof(struct lpm_trie_node) +
 			attr->value_size + trie->data_size;
 	cost += (u64) attr->max_entries * cost_per_node;
-	if (cost >= U32_MAX - PAGE_SIZE) {
-		ret = -E2BIG;
-		goto out_err;
-	}
 
-	ret = bpf_map_charge_init(&trie->map.memory,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	ret = bpf_map_charge_init(&trie->map.memory, cost);
 	if (ret)
 		goto out_err;
 

kernel/bpf/queue_stack_maps.c

@@ -73,10 +73,6 @@ static struct bpf_map *queue_stack_map_alloc(union bpf_attr *attr)
 
 	size = (u64) attr->max_entries + 1;
 	cost = queue_size = sizeof(*qs) + size * attr->value_size;
-	if (cost >= U32_MAX - PAGE_SIZE)
-		return ERR_PTR(-E2BIG);
-
-	cost = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
 
 	ret = bpf_map_charge_init(&mem, cost);
 	if (ret < 0)

kernel/bpf/reuseport_array.c

@@ -152,7 +152,7 @@ static struct bpf_map *reuseport_array_alloc(union bpf_attr *attr)
 	int err, numa_node = bpf_map_attr_numa_node(attr);
 	struct reuseport_array *array;
 	struct bpf_map_memory mem;
-	u64 cost, array_size;
+	u64 array_size;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
@@ -160,13 +160,7 @@ static struct bpf_map *reuseport_array_alloc(union bpf_attr *attr)
 	array_size = sizeof(*array);
 	array_size += (u64)attr->max_entries * sizeof(struct sock *);
 
-	/* make sure there is no u32 overflow later in round_up() */
-	cost = array_size;
-	if (cost >= U32_MAX - PAGE_SIZE)
-		return ERR_PTR(-ENOMEM);
-	cost = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
-
-	err = bpf_map_charge_init(&mem, cost);
+	err = bpf_map_charge_init(&mem, array_size);
 	if (err)
 		return ERR_PTR(err);
 

kernel/bpf/stackmap.c

@@ -117,14 +117,8 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
 	n_buckets = roundup_pow_of_two(attr->max_entries);
 
 	cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
-	if (cost >= U32_MAX - PAGE_SIZE)
-		return ERR_PTR(-E2BIG);
 	cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));
-	if (cost >= U32_MAX - PAGE_SIZE)
-		return ERR_PTR(-E2BIG);
-
-	err = bpf_map_charge_init(&mem,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	err = bpf_map_charge_init(&mem, cost);
 	if (err)
 		return ERR_PTR(err);
 

kernel/bpf/syscall.c

@@ -205,11 +205,16 @@ static void bpf_uncharge_memlock(struct user_struct *user, u32 pages)
 		atomic_long_sub(pages, &user->locked_vm);
 }
 
-int bpf_map_charge_init(struct bpf_map_memory *mem, u32 pages)
+int bpf_map_charge_init(struct bpf_map_memory *mem, size_t size)
 {
-	struct user_struct *user = get_current_user();
+	u32 pages = round_up(size, PAGE_SIZE) >> PAGE_SHIFT;
+	struct user_struct *user;
 	int ret;
 
+	if (size >= U32_MAX - PAGE_SIZE)
+		return -E2BIG;
+
+	user = get_current_user();
 	ret = bpf_charge_memlock(user, pages);
 	if (ret) {
 		free_uid(user);

kernel/bpf/xskmap.c

@@ -37,12 +37,9 @@ static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
 
 	cost = (u64)m->map.max_entries * sizeof(struct xdp_sock *);
 	cost += sizeof(struct list_head) * num_possible_cpus();
-	if (cost >= U32_MAX - PAGE_SIZE)
-		goto free_m;
 
 	/* Notice returns -EPERM on if map size is larger than memlock limit */
-	err = bpf_map_charge_init(&m->map.memory,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	err = bpf_map_charge_init(&m->map.memory, cost);
 	if (err)
 		goto free_m;
 

net/core/bpf_sk_storage.c

@@ -626,7 +626,6 @@ static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
 	struct bpf_sk_storage_map *smap;
 	unsigned int i;
 	u32 nbuckets;
-	u32 pages;
 	u64 cost;
 	int ret;
 
@@ -638,9 +637,8 @@ static struct bpf_map *bpf_sk_storage_map_alloc(union bpf_attr *attr)
 	smap->bucket_log = ilog2(roundup_pow_of_two(num_possible_cpus()));
 	nbuckets = 1U << smap->bucket_log;
 	cost = sizeof(*smap->buckets) * nbuckets + sizeof(*smap);
-	pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT;
 
-	ret = bpf_map_charge_init(&smap->map.memory, pages);
+	ret = bpf_map_charge_init(&smap->map.memory, cost);
 	if (ret < 0) {
 		kfree(smap);
 		return ERR_PTR(ret);

net/core/sock_map.c

@@ -44,13 +44,7 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
 
 	/* Make sure page count doesn't overflow. */
 	cost = (u64) stab->map.max_entries * sizeof(struct sock *);
-	if (cost >= U32_MAX - PAGE_SIZE) {
-		err = -EINVAL;
-		goto free_stab;
-	}
-
-	err = bpf_map_charge_init(&stab->map.memory,
-				  round_up(cost, PAGE_SIZE) >> PAGE_SHIFT);
+	err = bpf_map_charge_init(&stab->map.memory, cost);
 	if (err)
 		goto free_stab;