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: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Yonghong Song 2018-12-15 22:13:52 -08:00 committed by Daniel Borkmann
parent 9d5f9f701b
commit ffa0c1cf59
3 changed files with 36 additions and 23 deletions

View File

@ -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);

View File

@ -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;

View File

@ -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;