From: Chengkaitao <[email protected]> When traversing an rbtree using bpf_rbtree_left/right, if bpf_kptr_xchg is used to access the __kptr pointer contained in a node, it currently requires first removing the node with bpf_rbtree_remove and clearing the NON_OWN_REF flag, then re-adding the node to the original rbtree with bpf_rbtree_add after usage. This process significantly degrades rbtree traversal performance. The patch enables accessing __kptr pointers with the NON_OWN_REF flag set while holding the lock, eliminating the need for this remove-read-readd sequence.
Signed-off-by: Chengkaitao <[email protected]> Signed-off-by: Feng Yang <[email protected]> --- kernel/bpf/verifier.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 05a6a6606b6c..bb3ff4bbb3a2 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9260,7 +9260,8 @@ static const struct bpf_reg_types timer_types = { .types = { PTR_TO_MAP_VALUE } static const struct bpf_reg_types kptr_xchg_dest_types = { .types = { PTR_TO_MAP_VALUE, - PTR_TO_BTF_ID | MEM_ALLOC + PTR_TO_BTF_ID | MEM_ALLOC, + PTR_TO_BTF_ID | MEM_ALLOC | NON_OWN_REF } }; static const struct bpf_reg_types dynptr_types = { @@ -9420,6 +9421,7 @@ static int check_reg_type(struct bpf_verifier_env *env, u32 regno, } case PTR_TO_BTF_ID | MEM_ALLOC: case PTR_TO_BTF_ID | MEM_PERCPU | MEM_ALLOC: + case PTR_TO_BTF_ID | MEM_ALLOC | NON_OWN_REF: if (meta->func_id != BPF_FUNC_spin_lock && meta->func_id != BPF_FUNC_spin_unlock && meta->func_id != BPF_FUNC_kptr_xchg) { verifier_bug(env, "unimplemented handling of MEM_ALLOC"); -- 2.50.1 (Apple Git-155)
