From 9c395c1b99bd23f74bc628fa000480c49593d17f Mon Sep 17 00:00:00 2001 From: Dave Marchevsky Date: Mon, 13 Feb 2023 16:40:10 -0800 Subject: 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 Link: https://lore.kernel.org/r/20230214004017.2534011-2-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov --- include/linux/bpf.h | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8b5d0b4c4ada..be34f7deb6c3 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -181,7 +181,10 @@ enum btf_field_type { BPF_KPTR = BPF_KPTR_UNREF | BPF_KPTR_REF, BPF_LIST_HEAD = (1 << 4), BPF_LIST_NODE = (1 << 5), - BPF_GRAPH_NODE_OR_ROOT = BPF_LIST_NODE | BPF_LIST_HEAD, + BPF_RB_ROOT = (1 << 6), + BPF_RB_NODE = (1 << 7), + BPF_GRAPH_NODE_OR_ROOT = BPF_LIST_NODE | BPF_LIST_HEAD | + BPF_RB_NODE | BPF_RB_ROOT, }; struct btf_field_kptr { @@ -285,6 +288,10 @@ static inline const char *btf_field_type_name(enum btf_field_type type) return "bpf_list_head"; case BPF_LIST_NODE: return "bpf_list_node"; + case BPF_RB_ROOT: + return "bpf_rb_root"; + case BPF_RB_NODE: + return "bpf_rb_node"; default: WARN_ON_ONCE(1); return "unknown"; @@ -305,6 +312,10 @@ static inline u32 btf_field_type_size(enum btf_field_type type) return sizeof(struct bpf_list_head); case BPF_LIST_NODE: return sizeof(struct bpf_list_node); + case BPF_RB_ROOT: + return sizeof(struct bpf_rb_root); + case BPF_RB_NODE: + return sizeof(struct bpf_rb_node); default: WARN_ON_ONCE(1); return 0; @@ -325,6 +336,10 @@ static inline u32 btf_field_type_align(enum btf_field_type type) return __alignof__(struct bpf_list_head); case BPF_LIST_NODE: return __alignof__(struct bpf_list_node); + case BPF_RB_ROOT: + return __alignof__(struct bpf_rb_root); + case BPF_RB_NODE: + return __alignof__(struct bpf_rb_node); default: WARN_ON_ONCE(1); return 0; @@ -435,6 +450,9 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src, void bpf_timer_cancel_and_free(void *timer); void bpf_list_head_free(const struct btf_field *field, void *list_head, struct bpf_spin_lock *spin_lock); +void bpf_rb_root_free(const struct btf_field *field, void *rb_root, + struct bpf_spin_lock *spin_lock); + int bpf_obj_name_cpy(char *dst, const char *src, unsigned int size); -- cgit v1.2.3