Re: [PATCH 0/3] bpf: Store/dump license string for loaded program

[Jiri Olsa <jolsa@redhat.com>]

On Wed, Apr 25, 2018 at 10:15:29AM -0600, Alexei Starovoitov wrote:
> On Wed, Apr 25, 2018 at 12:17:13PM +0200, Jiri Olsa wrote:
> > On Mon, Apr 23, 2018 at 02:11:36PM -0600, Alexei Starovoitov wrote:
> > > On Mon, Apr 23, 2018 at 08:59:24AM +0200, Jiri Olsa wrote:
> > > > hi,
> > > > sending the change to store and dump the license
> > > > info for loaded BPF programs. It's important for
> > > > us get the license info, when investigating on
> > > > screwed up machine.
> > > 
> > > hmm. boolean flag whether bpf prog is gpl or not
> > > is already exposed via bpf_prog_info.
> > 
> > hum, I can't see that (on bpf-next/master)
> > would the attached change be ok with you?
> > 
> > jirka
> > 
> > 
> > ---
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index e6679393b687..2ce9c9d41c2b 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -1062,6 +1062,7 @@ struct bpf_prog_info {
> >  	__u32 ifindex;
> >  	__u64 netns_dev;
> >  	__u64 netns_ino;
> > +	__u16 gpl_compatible:1;
> >  } __attribute__((aligned(8)));
> 
> ahh. I swear there were patches to add it and I thought we accepted them.
> Also just noticed that commit 675fc275a3a2d added 4-byte hole in there.
> So I'm thinking we can fill the hole with 
>  	__u32 ifindex;
> +	__u32 gpl_compatible:1;
>  	__u64 netns_dev;
>  	__u64 netns_ino;
> 
> and keep adding bit fields in there without breaking user space.
> Such patch would need to go to bpf tree.
> 

ok, will post v2 with that

thanks,
jirka