From: Kaitao Cheng <[email protected]> For the following scenario: struct tree_node { struct bpf_refcount ref; struct bpf_rb_node node; struct node_data __kptr * node_data; u64 key; }; This means node_data would have the type PTR_TO_BTF_ID | MEM_ALLOC | NON_OWN_REF | MEM_RCU.
When traversing an rbtree using bpf_rbtree_left/right, if we need to use bpf_kptr_xchg to read the __kptr pointer, we still need to follow the remove-read-add sequence. This patch allows us to use bpf_kptr_xchg to directly read the __kptr pointer without any prior operations. Signed-off-by: Kaitao Cheng <[email protected]> Signed-off-by: Feng Yang <[email protected]> --- kernel/bpf/verifier.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 3536a91ff8c7..5baa12af3a4e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9320,6 +9320,7 @@ static const struct bpf_reg_types percpu_btf_ptr_types = { PTR_TO_BTF_ID | MEM_PERCPU, PTR_TO_BTF_ID | MEM_PERCPU | MEM_RCU, PTR_TO_BTF_ID | MEM_PERCPU | PTR_TRUSTED, + PTR_TO_BTF_ID | MEM_ALLOC | NON_OWN_REF | MEM_RCU, } }; static const struct bpf_reg_types func_ptr_types = { .types = { PTR_TO_FUNC } }; @@ -9491,6 +9492,7 @@ 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: + case PTR_TO_BTF_ID | MEM_ALLOC | NON_OWN_REF | MEM_RCU: 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)
