Commit c85d6913 authored May 29, 2019 by Roman Gushchin Committed by Alexei Starovoitov May 31, 2019

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>

parent b936ca64

include/linux/bpf.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -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

+1 −7

Original line number	Diff line number	Diff line
		@@ -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

+1 −4

Original line number	Diff line number	Diff line
		@@ -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

+1 −4

Original line number	Diff line number	Diff line
		@@ -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

+1 −6

Original line number	Diff line number	Diff line
		@@ -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;