Commit ffa0c1cf authored by Yonghong Song's avatar Yonghong Song Committed by Daniel Borkmann
Browse files

bpf: enable cgroup local storage map pretty print with kind_flag 



Commit 970289fc0a83 ("bpf: add bpffs pretty print for cgroup
local storage maps") added bpffs pretty print for cgroup
local storage maps. The commit worked for struct without kind_flag
set.

This patch refactored and made pretty print also work
with kind_flag set for the struct.

Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 9d5f9f70

include/linux/btf.h

+4 −1
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/types.h>



struct btf;

struct btf_member;

struct btf_type;

union bpf_attr;
@@ -46,7 +47,9 @@ void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, 
		       struct seq_file *m);

int btf_get_fd_by_id(u32 id);

u32 btf_id(const struct btf *btf);

bool btf_type_is_reg_int(const struct btf_type *t, u32 expected_size);

bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,

			   const struct btf_member *m,

			   u32 expected_offset, u32 expected_size);



#ifdef CONFIG_BPF_SYSCALL

const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id);

kernel/bpf/btf.c

+28 −9
Original line number Diff line number Diff line
@@ -546,22 +546,41 @@ static bool btf_type_int_is_regular(const struct btf_type *t) 
}



/*

 * Check that given type is a regular int and has the expected size.

 * Check that given struct member is a regular int with expected

 * offset and size.

 */

bool btf_type_is_reg_int(const struct btf_type *t, u32 expected_size)

bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s,

			   const struct btf_member *m,

			   u32 expected_offset, u32 expected_size)

{

	u8 nr_bits, nr_bytes;

	u32 int_data;

	const struct btf_type *t;

	u32 id, int_data;

	u8 nr_bits;



	if (!btf_type_is_int(t))

	id = m->type;

	t = btf_type_id_size(btf, &id, NULL);

	if (!t || !btf_type_is_int(t))

		return false;



	int_data = btf_type_int(t);

	nr_bits = BTF_INT_BITS(int_data);

	nr_bytes = BITS_ROUNDUP_BYTES(nr_bits);

	if (BITS_PER_BYTE_MASKED(nr_bits) ||

	    BTF_INT_OFFSET(int_data) ||

	    nr_bytes != expected_size)

	if (btf_type_kflag(s)) {

		u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset);

		u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset);



		/* if kflag set, int should be a regular int and

		 * bit offset should be at byte boundary.

		 */

		return !bitfield_size &&

		       BITS_ROUNDUP_BYTES(bit_offset) == expected_offset &&

		       BITS_ROUNDUP_BYTES(nr_bits) == expected_size;

	}



	if (BTF_INT_OFFSET(int_data) ||

	    BITS_PER_BYTE_MASKED(m->offset) ||

	    BITS_ROUNDUP_BYTES(m->offset) != expected_offset ||

	    BITS_PER_BYTE_MASKED(nr_bits) ||

	    BITS_ROUNDUP_BYTES(nr_bits) != expected_size)

		return false;



	return true;

kernel/bpf/local_storage.c

+4 −13
Original line number Diff line number Diff line
@@ -315,9 +315,8 @@ static int cgroup_storage_check_btf(const struct bpf_map *map, 
				    const struct btf_type *key_type,

				    const struct btf_type *value_type)

{

	const struct btf_type *t;

	struct btf_member *m;

	u32 id, size;

	u32 offset, size;



	/* Key is expected to be of struct bpf_cgroup_storage_key type,

	 * which is:
@@ -338,25 +337,17 @@ static int cgroup_storage_check_btf(const struct bpf_map *map, 
	 * The first field must be a 64 bit integer at 0 offset.

	 */

	m = (struct btf_member *)(key_type + 1);

	if (m->offset)

		return -EINVAL;

	id = m->type;

	t = btf_type_id_size(btf, &id, NULL);

	size = FIELD_SIZEOF(struct bpf_cgroup_storage_key, cgroup_inode_id);

	if (!t || !btf_type_is_reg_int(t, size))

	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++;

	if (m->offset != offsetof(struct bpf_cgroup_storage_key, attach_type) *

	    BITS_PER_BYTE)

		return -EINVAL;

	id = m->type;

	t = btf_type_id_size(btf, &id, NULL);

	offset = offsetof(struct bpf_cgroup_storage_key, attach_type);

	size = FIELD_SIZEOF(struct bpf_cgroup_storage_key, attach_type);

	if (!t || !btf_type_is_reg_int(t, size))

	if (!btf_member_is_reg_int(btf, key_type, m, offset, size))

		return -EINVAL;



	return 0;