Re: [PATCHv2 bpf-next 02/15] bpf: Add minimal bpf() command documentation

[Yonghong Song <yhs@fb.com>]

On 3/2/21 9:19 AM, Joe Stringer wrote:
> Introduce high-level descriptions of the intent and return codes of the
> bpf() syscall commands. Subsequent patches may further flesh out the
> content to provide a more useful programming reference.
> 
> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
> Reviewed-by: Quentin Monnet <quentin@isovalent.com>
> Signed-off-by: Joe Stringer <joe@cilium.io>

With a nit to update NOTES section,
Acked-by: Yonghong Song <yhs@fb.com>

> ---
>   include/uapi/linux/bpf.h | 368 +++++++++++++++++++++++++++++++++++++++
>   1 file changed, 368 insertions(+)
> 
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index fb16c590e6d9..052bbfe65f77 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -204,6 +204,374 @@ union bpf_iter_link_info {
>    *		A new file descriptor (a nonnegative integer), or -1 if an
>    *		error occurred (in which case, *errno* is set appropriately).
>    *
> + * BPF_OBJ_PIN
> + *	Description
> + *		Pin an eBPF program or map referred by the specified *bpf_fd*
> + *		to the provided *pathname* on the filesystem.
> + *
> + *	Return
> + *		Returns zero on success. On error, -1 is returned and *errno*
> + *		is set appropriately.
> + *
> + * BPF_OBJ_GET
> + *	Description
> + *		Open a file descriptor for the eBPF object pinned to the
> + *		specified *pathname*.
> + *
> + *	Return
> + *		A new file descriptor (a nonnegative integer), or -1 if an
> + *		error occurred (in which case, *errno* is set appropriately).
> + *
[...]
> + * BPF_PROG_BIND_MAP
> + *	Description
> + *		Bind a map to the lifetime of an eBPF program.
> + *
> + *		The map identified by *map_fd* is bound to the program
> + *		identified by *prog_fd* and only released when *prog_fd* is
> + *		released. This may be used in cases where metadata should be
> + *		associated with a program which otherwise does not contain any
> + *		references to the map (for example, embedded in the eBPF
> + *		program instructions).
> + *
> + *	Return
> + *		Returns zero on success. On error, -1 is returned and *errno*
> + *		is set appropriately.
> + *
>    * NOTES
>    *	eBPF objects (maps and programs) can be shared between processes.
>    *	For example, after **fork**\ (2), the child inherits file descriptors
>