diff options
| author | Dave Marchevsky <davemarchevsky@fb.com> | 2023-02-14 03:40:10 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-02-14 06:31:13 +0300 |
| commit | 9c395c1b99bd23f74bc628fa000480c49593d17f (patch) | |
| tree | 94f458b2c20a60847746c3a08682fd0a42b70b7b /kernel/bpf/syscall.c | |
| parent | 6a3cd3318ff65622415e34e8ee39d76331e7c869 (diff) | |
| download | linux-9c395c1b99bd23f74bc628fa000480c49593d17f.tar.xz | |
bpf: Add basic bpf_rb_{root,node} support
This patch adds special BPF_RB_{ROOT,NODE} btf_field_types similar to
BPF_LIST_{HEAD,NODE}, adds the necessary plumbing to detect the new
types, and adds bpf_rb_root_free function for freeing bpf_rb_root in
map_values.
structs bpf_rb_root and bpf_rb_node are opaque types meant to
obscure structs rb_root_cached rb_node, respectively.
btf_struct_access will prevent BPF programs from touching these special
fields automatically now that they're recognized.
btf_check_and_fixup_fields now groups list_head and rb_root together as
"graph root" fields and {list,rb}_node as "graph node", and does same
ownership cycle checking as before. Note that this function does _not_
prevent ownership type mixups (e.g. rb_root owning list_node) - that's
handled by btf_parse_graph_root.
After this patch, a bpf program can have a struct bpf_rb_root in a
map_value, but not add anything to nor do anything useful with it.
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/r/20230214004017.2534011-2-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/syscall.c')
| -rw-r--r-- | kernel/bpf/syscall.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index cda8d00f3762..e3fcdc9836a6 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -537,9 +537,6 @@ void btf_record_free(struct btf_record *rec) return; for (i = 0; i < rec->cnt; i++) { switch (rec->fields[i].type) { - case BPF_SPIN_LOCK: - case BPF_TIMER: - break; case BPF_KPTR_UNREF: case BPF_KPTR_REF: if (rec->fields[i].kptr.module) @@ -548,7 +545,11 @@ void btf_record_free(struct btf_record *rec) break; case BPF_LIST_HEAD: case BPF_LIST_NODE: - /* Nothing to release for bpf_list_head */ + case BPF_RB_ROOT: + case BPF_RB_NODE: + case BPF_SPIN_LOCK: + case BPF_TIMER: + /* Nothing to release */ break; default: WARN_ON_ONCE(1); @@ -581,9 +582,6 @@ struct btf_record *btf_record_dup(const struct btf_record *rec) new_rec->cnt = 0; for (i = 0; i < rec->cnt; i++) { switch (fields[i].type) { - case BPF_SPIN_LOCK: - case BPF_TIMER: - break; case BPF_KPTR_UNREF: case BPF_KPTR_REF: btf_get(fields[i].kptr.btf); @@ -594,7 +592,11 @@ struct btf_record *btf_record_dup(const struct btf_record *rec) break; case BPF_LIST_HEAD: case BPF_LIST_NODE: - /* Nothing to acquire for bpf_list_head */ + case BPF_RB_ROOT: + case BPF_RB_NODE: + case BPF_SPIN_LOCK: + case BPF_TIMER: + /* Nothing to acquire */ break; default: ret = -EFAULT; @@ -674,7 +676,13 @@ void bpf_obj_free_fields(const struct btf_record *rec, void *obj) continue; bpf_list_head_free(field, field_ptr, obj + rec->spin_lock_off); break; + case BPF_RB_ROOT: + if (WARN_ON_ONCE(rec->spin_lock_off < 0)) + continue; + bpf_rb_root_free(field, field_ptr, obj + rec->spin_lock_off); + break; case BPF_LIST_NODE: + case BPF_RB_NODE: break; default: WARN_ON_ONCE(1); @@ -1010,7 +1018,8 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, return -EINVAL; map->record = btf_parse_fields(btf, value_type, - BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD, + BPF_SPIN_LOCK | BPF_TIMER | BPF_KPTR | BPF_LIST_HEAD | + BPF_RB_ROOT, map->value_size); if (!IS_ERR_OR_NULL(map->record)) { int i; @@ -1058,6 +1067,7 @@ static int map_check_btf(struct bpf_map *map, const struct btf *btf, } break; case BPF_LIST_HEAD: + case BPF_RB_ROOT: if (map->map_type != BPF_MAP_TYPE_HASH && map->map_type != BPF_MAP_TYPE_LRU_HASH && map->map_type != BPF_MAP_TYPE_ARRAY) { |