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author | Yonghong Song <yonghong.song@linux.dev> | 2023-08-27 08:27:39 -0700 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2023-09-08 08:42:17 -0700 |
commit | 55db92f42fe4a4ef7b4c2b4960c6212c8512dd53 (patch) | |
tree | a2c0c5e59771d18ca0fb8e8979a821b022e8c333 /kernel/bpf/btf.c | |
parent | 41a5db8d8161457b121a03fde999ff6e00090ee2 (diff) | |
download | lwn-55db92f42fe4a4ef7b4c2b4960c6212c8512dd53.tar.gz lwn-55db92f42fe4a4ef7b4c2b4960c6212c8512dd53.zip |
bpf: Add BPF_KPTR_PERCPU as a field type
BPF_KPTR_PERCPU represents a percpu field type like below
struct val_t {
... fields ...
};
struct t {
...
struct val_t __percpu_kptr *percpu_data_ptr;
...
};
where
#define __percpu_kptr __attribute__((btf_type_tag("percpu_kptr")))
While BPF_KPTR_REF points to a trusted kernel object or a trusted
local object, BPF_KPTR_PERCPU points to a trusted local
percpu object.
This patch added basic support for BPF_KPTR_PERCPU
related to percpu_kptr field parsing, recording and free operations.
BPF_KPTR_PERCPU also supports the same map types
as BPF_KPTR_REF does.
Note that unlike a local kptr, it is possible that
a BPF_KTPR_PERCPU struct may not contain any
special fields like other kptr, bpf_spin_lock, bpf_list_head, etc.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152739.1996391-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/btf.c')
-rw-r--r-- | kernel/bpf/btf.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 1095bbe29859..187b57276fec 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3293,6 +3293,8 @@ static int btf_find_kptr(const struct btf *btf, const struct btf_type *t, type = BPF_KPTR_UNREF; else if (!strcmp("kptr", __btf_name_by_offset(btf, t->name_off))) type = BPF_KPTR_REF; + else if (!strcmp("percpu_kptr", __btf_name_by_offset(btf, t->name_off))) + type = BPF_KPTR_PERCPU; else return -EINVAL; @@ -3457,6 +3459,7 @@ static int btf_find_struct_field(const struct btf *btf, break; case BPF_KPTR_UNREF: case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: ret = btf_find_kptr(btf, member_type, off, sz, idx < info_cnt ? &info[idx] : &tmp); if (ret < 0) @@ -3523,6 +3526,7 @@ static int btf_find_datasec_var(const struct btf *btf, const struct btf_type *t, break; case BPF_KPTR_UNREF: case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: ret = btf_find_kptr(btf, var_type, off, sz, idx < info_cnt ? &info[idx] : &tmp); if (ret < 0) @@ -3783,6 +3787,7 @@ struct btf_record *btf_parse_fields(const struct btf *btf, const struct btf_type break; case BPF_KPTR_UNREF: case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: ret = btf_parse_kptr(btf, &rec->fields[i], &info_arr[i]); if (ret < 0) goto end; |