Re: [PATCHv2 bpf-next 13/15] selftests/bpf: Test syscall command parsing

On Wed, Mar 3, 2021 at 2:23 PM Yonghong Song [off-list ref] wrote:

On 3/2/21 9:19 AM, Joe Stringer wrote:

quoted

Add building of the bpf(2) syscall commands documentation as part of the
docs building step in the build. This allows us to pick up on potential
parse errors from the docs generator script as part of selftests.

The generated manual pages here are not intended for distribution, they
are just a fragment that can be integrated into the other static text of
bpf(2) to form the full manual page.

I tried and the generated bpf(2) man page looks like:

BPF(2)

                          BPF(2)

NAME
        bpf - Perform a command on an extended BPF object

COMMANDS
        BPF_MAP_CREATE

               Description
                      Create  a map and return a file descriptor that
refers to the map. The close-on-exec file descriptor flag (see fcntl(2))
is automatically enabled for the
                      new file descriptor.

                      Applying close(2) to the file descriptor returned
by BPF_MAP_CREATE will delete the map (but see NOTES).

               Return A new file descriptor (a nonnegative integer), or
-1 if an error occurred (in which case, errno is set appropriately).

        BPF_MAP_LOOKUP_ELEM
...
        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.


Yes, this needs to be integrated into the real man page. But this is
already great so people can see latest bpf latest features without
going to the source code. Thanks!

:party-parrot:

Yeah I think the step around integrating into the real man page is an
area that folks may have opinions on and I'm CC'ing Michael here in
particular, but ultimately that manual is currently managed in the
upstream manpages tree so nothing actionable from this series,
absolute simplest is for someone (is that me?) to just package this
hunk up and submit it to the upstream tree every once in a while.
Slightly more elaborate would involve integrating the static text with
this generated text somewhere (either kernel tree or manpages tree)
and have someone run a cron job to generate & submit the changes.
Could be another option, these are the obvious ones that come to mind.

quoted

Acked-by: Toke Høiland-Jørgensen <redacted>
Reviewed-by: Quentin Monnet <redacted>
Signed-off-by: Joe Stringer <redacted>

Acked-by: Yonghong Song <redacted>