netdev - [PATCH bpf] bpf: Only print ref_obj

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Date:   Mon, 18 Mar 2019 10:37:13 -0700
From:   Martin KaFai Lau <kafai@...com>
To:     <bpf@...r.kernel.org>, <netdev@...r.kernel.org>
CC:     Alexei Starovoitov <ast@...com>,
        Daniel Borkmann <daniel@...earbox.net>, <kernel-team@...com>,
        Naresh Kamboju <naresh.kamboju@...aro.org>
Subject: [PATCH bpf] bpf: Only print ref_obj_id for refcounted reg

Naresh reported that test_align fails because of the mismatch at the
verbose printout of the register states.  The reason is due to the newly
added ref_obj_id.

ref_obj_id is only useful for refcounted reg.  Thus, this patch fixes it
by only printing ref_obj_id for refcounted reg.  While at it, it also uses
comma instead of space to separate between "id" and "ref_obj_id".

Fixes: 1b986589680a ("bpf: Fix bpf_tcp_sock and bpf_sk_fullsock issue related to bpf_sk_release")
Reported-by: Naresh Kamboju <naresh.kamboju@...aro.org>
Signed-off-by: Martin KaFai Lau <kafai@...com>
---
 kernel/bpf/verifier.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 86f9cd5d1c4e..5aa810882583 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -352,6 +352,14 @@ static bool reg_may_point_to_spin_lock(const struct bpf_reg_state *reg)
 		map_value_has_spin_lock(reg->map_ptr);
 }
 
+static bool reg_type_may_be_refcounted_or_null(enum bpf_reg_type type)
+{
+	return type == PTR_TO_SOCKET ||
+		type == PTR_TO_SOCKET_OR_NULL ||
+		type == PTR_TO_TCP_SOCK ||
+		type == PTR_TO_TCP_SOCK_OR_NULL;
+}
+
 static bool arg_type_may_be_refcounted(enum bpf_arg_type type)
 {
 	return type == ARG_PTR_TO_SOCK_COMMON;
@@ -451,8 +459,9 @@ static void print_verifier_state(struct bpf_verifier_env *env,
 			if (t == PTR_TO_STACK)
 				verbose(env, ",call_%d", func(env, reg)->callsite);
 		} else {
-			verbose(env, "(id=%d ref_obj_id=%d", reg->id,
-				reg->ref_obj_id);
+			verbose(env, "(id=%d", reg->id);
+			if (reg_type_may_be_refcounted_or_null(t))
+				verbose(env, ",ref_obj_id=%d", reg->ref_obj_id);
 			if (t != SCALAR_VALUE)
 				verbose(env, ",off=%d", reg->off);
 			if (type_is_pkt_pointer(t))
-- 
2.17.1