Re: [RFC bpf-next v4 4/7] btf: Add a new kfunc set which allows to mark a function to be sleepable

From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
	Jiri Kosina <jikos@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>,
	Tero Kristo <tero.kristo@linux.intel.com>,
	linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
	bpf@vger.kernel.org
Subject: Re: [RFC bpf-next v4 4/7] btf: Add a new kfunc set which allows to mark a function to be sleepable
Date: Mon, 25 Apr 2022 21:12:20 -0700	[thread overview]
Message-ID: <20220426041220.xsblwpvmcvceyaco@MBP-98dd607d3435.dhcp.thefacebook.com> (raw)
In-Reply-To: <20220421140740.459558-5-benjamin.tissoires@redhat.com>

On Thu, Apr 21, 2022 at 04:07:37PM +0200, Benjamin Tissoires wrote:
> This allows to declare a kfunc as sleepable and prevents its use in
> a non sleepable program.
> 
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

makes sense.
> @@ -17,6 +17,7 @@ enum btf_kfunc_type {
>  	BTF_KFUNC_TYPE_ACQUIRE,
>  	BTF_KFUNC_TYPE_RELEASE,
>  	BTF_KFUNC_TYPE_RET_NULL,
> +	BTF_KFUNC_TYPE_SLEEPABLE,
>  	BTF_KFUNC_TYPE_MAX,
>  };
>  
> @@ -35,6 +36,7 @@ struct btf_kfunc_id_set {
>  			struct btf_id_set *acquire_set;
>  			struct btf_id_set *release_set;
>  			struct btf_id_set *ret_null_set;
> +			struct btf_id_set *sleepable_set;