Re: [bpf PATCH v2 1/3] bpf: tls, implement unhash to avoid transition out of ESTABLISHED

[Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>]

On Thu, 25 Apr 2019 09:03:08 -0700, John Fastabend wrote:
> +static void tls_sk_proto_unhash(struct sock *sk)
> +{
> +	struct tls_context *ctx = tls_get_ctx(sk);
> +	void (*sk_proto_unhash)(struct sock *sk);
> +	bool free_ctx;
> +
> +	if (!ctx)
> +		return sk->sk_prot->unhash(sk);
> +	sk_proto_unhash = ctx->sk_proto_unhash;
> +	free_ctx = tls_sk_proto_destroy(sk, ctx, false);
> +	tls_put_ctx(sk);

Oh, I think you can't put_ctx() unconditionally,
when free_ctx is false, tls_device_sk_destruct() 
needs it the ctx pointer.

I think this explains the offload crashing.

> +	if (sk_proto_unhash)
> +		sk_proto_unhash(sk);
> +	if (free_ctx)
> +		tls_ctx_free(ctx);
> +}
>  
> -skip_tx_cleanup:
> +static void tls_sk_proto_close(struct sock *sk, long timeout)
> +{
> +	void (*sk_proto_close)(struct sock *sk, long timeout);
> +	struct tls_context *ctx = tls_get_ctx(sk);
> +	bool free_ctx;
> +
> +	if (!ctx)
> +		return sk->sk_prot->destroy(sk);
> +
> +	lock_sock(sk);
> +	sk_proto_close = ctx->sk_proto_close;
> +	free_ctx = tls_sk_proto_destroy(sk, ctx, true);
> +	tls_put_ctx(sk);