Re: [PATCH 3/3] module: Properly propagate MODULE_STATE_COMING failure

[Peter Zijlstra <peterz@infradead.org>]

On Mon, Jun 24, 2019 at 11:18:46AM +0200, Peter Zijlstra wrote:
> Now that notifiers got unbroken; use the proper interface to handle
> notifier errors and propagate them.
> 
> There were already MODULE_STATE_COMING notifiers that failed; notably:
> 
>  - jump_label_module_notifier()
>  - tracepoint_module_notify()
>  - bpf_event_notify()
> 
> By propagating this error, we fix those users.
> 
> Cc: Jessica Yu <jeyu@kernel.org>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Martin KaFai Lau <kafai@fb.com>
> Cc: Song Liu <songliubraving@fb.com>
> Cc: Yonghong Song <yhs@fb.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Cc: bpf@vger.kernel.org
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> ---
>  kernel/module.c |    7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -3643,9 +3643,10 @@ static int prepare_coming_module(struct
>  	if (err)
>  		return err;
>  
> -	blocking_notifier_call_chain(&module_notify_list,
> -				     MODULE_STATE_COMING, mod);
> -	return 0;
> +	err = blocking_notifier_call_chain_error(&module_notify_list,
> +			MODULE_STATE_COMING, MODULE_STATE_GOING, mod);
> +
> +	return notifier_to_errno(err);
>  }

Argh, I messed up that klp thing again :/