diff options
| 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/syscall.c | |
| parent | 41a5db8d8161457b121a03fde999ff6e00090ee2 (diff) | |
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/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index eb01c31ed591..6a692f3bea15 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -514,6 +514,7 @@ void btf_record_free(struct btf_record *rec) switch (rec->fields[i].type) { case BPF_KPTR_UNREF: case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: if (rec->fields[i].kptr.module) module_put(rec->fields[i].kptr.module); btf_put(rec->fields[i].kptr.btf); @@ -560,6 +561,7 @@ struct btf_record *btf_record_dup(const struct btf_record *rec) switch (fields[i].type) { case BPF_KPTR_UNREF: case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: btf_get(fields[i].kptr.btf); if (fields[i].kptr.module && !try_module_get(fields[i].kptr.module)) { ret = -ENXIO; @@ -650,6 +652,7 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj) WRITE_ONCE(*(u64 *)field_ptr, 0); break; case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: xchgd_field = (void *)xchg((unsigned long *)field_ptr, 0); if (!xchgd_field) break; @@ -1045,6 +1048,7 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, break; case BPF_KPTR_UNREF: case BPF_KPTR_REF: + case BPF_KPTR_PERCPU: case BPF_REFCOUNT: if (map->map_type != BPF_MAP_TYPE_HASH && map->map_type != BPF_MAP_TYPE_PERCPU_HASH && |