[RFC PATCH bpf-next v2 6/9] bpf: Convert PTR_TO_MEM_OR_NULL to composable types.

[Hao Luo <haoluo@google.com>]

Remove PTR_TO_MEM_OR_NULL and replace it with PTR_TO_MEM combined with
flag PTR_MAYBE_NULL.

Signed-off-by: Hao Luo <haoluo@google.com>
---
 include/linux/bpf.h   | 1 -
 kernel/bpf/btf.c      | 2 +-
 kernel/bpf/verifier.c | 2 +-
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 61b72dbaeae8..19d27d5a1d94 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -514,7 +514,6 @@ enum bpf_reg_type {
 	PTR_TO_SOCK_COMMON_OR_NULL	= PTR_MAYBE_NULL | PTR_TO_SOCK_COMMON,
 	PTR_TO_TCP_SOCK_OR_NULL		= PTR_MAYBE_NULL | PTR_TO_TCP_SOCK,
 	PTR_TO_BTF_ID_OR_NULL		= PTR_MAYBE_NULL | PTR_TO_BTF_ID,
-	PTR_TO_MEM_OR_NULL		= PTR_MAYBE_NULL | PTR_TO_MEM,
 
 	/* This must be the last entry. Its purpose is to ensure the enum is
 	 * wide enough to hold the higher bits reserved for bpf_type_flag.
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 19ddd6fe5663..776b90de0971 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5861,7 +5861,7 @@ int btf_prepare_func_args(struct bpf_verifier_env *env, int subprog,
 				return -EINVAL;
 			}
 
-			reg->type = PTR_TO_MEM_OR_NULL;
+			reg->type = PTR_TO_MEM | PTR_MAYBE_NULL;
 			reg->id = ++env->id_gen;
 
 			continue;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 27f3440f4b18..72c7135bee3e 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -13313,7 +13313,7 @@ static int do_check_common(struct bpf_verifier_env *env, int subprog)
 				mark_reg_known_zero(env, regs, i);
 			else if (regs[i].type == SCALAR_VALUE)
 				mark_reg_unknown(env, regs, i);
-			else if (regs[i].type == PTR_TO_MEM_OR_NULL) {
+			else if (BPF_BASE_TYPE(regs[i].type) == PTR_TO_MEM) {
 				const u32 mem_size = regs[i].mem_size;
 
 				mark_reg_known_zero(env, regs, i);
-- 
2.34.0.384.gca35af8252-goog