Re: [PATCH v3 net-next 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info

From: Daniel Borkmann <daniel@iogearbox.net>
To: Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org
Cc: "Alexei Starovoitov" <ast@kernel.org>,
	bpf@vger.kernel.org, "Toke Høiland-Jørgensen" <toke@redhat.com>
Subject: Re: [PATCH v3 net-next 2/2] bpf: let bpf_warn_invalid_xdp_action() report more info
Date: Fri, 3 Dec 2021 23:04:27 +0100	[thread overview]
Message-ID: <1ac2941f-b751-9cf0-f0e3-ea0f245b7503@iogearbox.net> (raw)
In-Reply-To: <ddb96bb975cbfddb1546cf5da60e77d5100b533c.1638189075.git.pabeni@redhat.com>

Hi Paolo,

Changes look good to me as well, we can route the series via bpf-next after tree
resync, or alternatively ask David/Jakub to take it directly into net-next with our
Ack given in bpf-next there is no drivers/net/ethernet/microsoft/mana/mana_bpf.c yet.

On 11/30/21 11:08 AM, Paolo Abeni wrote:
[...]> diff --git a/net/core/filter.c b/net/core/filter.c
> index 5631acf3f10c..392838fa7652 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -8181,13 +8181,13 @@ static bool xdp_is_valid_access(int off, int size,
>   	return __is_valid_xdp_access(off, size);
>   }
>   
> -void bpf_warn_invalid_xdp_action(u32 act)
> +void bpf_warn_invalid_xdp_action(struct net_device *dev, struct bpf_prog *prog, u32 act)
>   {
>   	const u32 act_max = XDP_REDIRECT;
>   
> -	pr_warn_once("%s XDP return value %u, expect packet loss!\n",
> +	pr_warn_once("%s XDP return value %u on prog %s (id %d) dev %s, expect packet loss!\n",
>   		     act > act_max ? "Illegal" : "Driver unsupported",
> -		     act);
> +		     act, prog->aux->name, prog->aux->id, dev ? dev->name : "");

One tiny nit, but we could fix it up while applying I'd have is that for !dev case
we should probably dump a "<n/a>" or so just to avoid a kernel log message like
"dev , expect packet loss".

>   }
>   EXPORT_SYMBOL_GPL(bpf_warn_invalid_xdp_action);
>   

Thanks,
Daniel