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[81.187.253.111]) by smtp.gmail.com with ESMTPSA id v2sm9104408wrm.16.2020.09.04.04.24.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Sep 2020 04:24:19 -0700 (PDT) From: Lorenz Bauer To: ast@kernel.org, yhs@fb.com, daniel@iogearbox.net, kafai@fb.com Cc: bpf@vger.kernel.org, kernel-team@cloudflare.com, Lorenz Bauer Subject: [PATCH bpf-next 06/11] bpf: make reference tracking in check_func_arg generic Date: Fri, 4 Sep 2020 12:23:56 +0100 Message-Id: <20200904112401.667645-7-lmb@cloudflare.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200904112401.667645-1-lmb@cloudflare.com> References: <20200904112401.667645-1-lmb@cloudflare.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Instead of dealing with reg->ref_obj_id individually for every arg type that needs it, rely on the fact that ref_obj_id is zero if the register is not reference tracked. Signed-off-by: Lorenz Bauer Acked-by: Andrii Nakryiko --- kernel/bpf/verifier.c | 26 ++++++++++---------------- 1 file changed, 10 insertions(+), 16 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 45759638e1b8..c7df4ccad8e2 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3988,15 +3988,6 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, /* Any sk pointer can be ARG_PTR_TO_SOCK_COMMON */ if (!type_is_sk_pointer(type)) goto err_type; - if (reg->ref_obj_id) { - if (meta->ref_obj_id) { - verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", - regno, reg->ref_obj_id, - meta->ref_obj_id); - return -EFAULT; - } - meta->ref_obj_id = reg->ref_obj_id; - } } else if (arg_type == ARG_PTR_TO_SOCKET || arg_type == ARG_PTR_TO_SOCKET_OR_NULL) { expected_type = PTR_TO_SOCKET; @@ -4047,13 +4038,6 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, /* final test in check_stack_boundary() */; else if (type != expected_type) goto err_type; - if (meta->ref_obj_id) { - verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", - regno, reg->ref_obj_id, - meta->ref_obj_id); - return -EFAULT; - } - meta->ref_obj_id = reg->ref_obj_id; } else if (arg_type_is_int_ptr(arg_type)) { expected_type = PTR_TO_STACK; if (!type_is_pkt_pointer(type) && @@ -4087,6 +4071,16 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, } } + if (reg->ref_obj_id) { + if (meta->ref_obj_id) { + verbose(env, "verifier internal error: more than one arg with ref_obj_id R%d %u %u\n", + regno, reg->ref_obj_id, + meta->ref_obj_id); + return -EFAULT; + } + meta->ref_obj_id = reg->ref_obj_id; + } + if (arg_type == ARG_CONST_MAP_PTR) { /* bpf_map_xxx(map_ptr) call: remember that map_ptr */ meta->map_ptr = reg->map_ptr;