netdev - Re: [PATCH 09/11] bpf: Add d

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200623201447.GM2619137@krava>
Date:   Tue, 23 Jun 2020 22:14:47 +0200
From:   Jiri Olsa <jolsa@...hat.com>
To:     Andrii Nakryiko <andrii.nakryiko@...il.com>
Cc:     Jiri Olsa <jolsa@...nel.org>, Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Networking <netdev@...r.kernel.org>, bpf <bpf@...r.kernel.org>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        Martin KaFai Lau <kafai@...com>,
        David Miller <davem@...hat.com>,
        John Fastabend <john.fastabend@...il.com>,
        Wenbo Zhang <ethercflow@...il.com>,
        KP Singh <kpsingh@...omium.org>,
        Andrii Nakryiko <andriin@...com>,
        Brendan Gregg <bgregg@...flix.com>,
        Florent Revest <revest@...omium.org>,
        Al Viro <viro@...iv.linux.org.uk>
Subject: Re: [PATCH 09/11] bpf: Add d_path helper

On Tue, Jun 23, 2020 at 11:58:33AM -0700, Andrii Nakryiko wrote:
> On Tue, Jun 23, 2020 at 3:02 AM Jiri Olsa <jolsa@...hat.com> wrote:
> >
> > On Mon, Jun 22, 2020 at 12:18:19PM -0700, Andrii Nakryiko wrote:
> > > On Mon, Jun 22, 2020 at 2:02 AM Jiri Olsa <jolsa@...hat.com> wrote:
> > > >
> > > > On Fri, Jun 19, 2020 at 11:25:27AM -0700, Andrii Nakryiko wrote:
> > > >
> > > > SNIP
> > > >
> > > > > > > >  /* integer value in 'imm' field of BPF_CALL instruction selects which helper
> > > > > > > >   * function eBPF program intends to call
> > > > > > > > diff --git a/kernel/bpf/btf_ids.c b/kernel/bpf/btf_ids.c
> > > > > > > > index d8d0df162f04..853c8fd59b06 100644
> > > > > > > > --- a/kernel/bpf/btf_ids.c
> > > > > > > > +++ b/kernel/bpf/btf_ids.c
> > > > > > > > @@ -13,3 +13,14 @@ BTF_ID(struct, seq_file)
> > > > > > > >
> > > > > > > >  BTF_ID_LIST(bpf_xdp_output_btf_ids)
> > > > > > > >  BTF_ID(struct, xdp_buff)
> > > > > > > > +
> > > > > > > > +BTF_ID_LIST(bpf_d_path_btf_ids)
> > > > > > > > +BTF_ID(struct, path)
> > > > > > > > +
> > > > > > > > +BTF_WHITELIST_ENTRY(btf_whitelist_d_path)
> > > > > > > > +BTF_ID(func, vfs_truncate)
> > > > > > > > +BTF_ID(func, vfs_fallocate)
> > > > > > > > +BTF_ID(func, dentry_open)
> > > > > > > > +BTF_ID(func, vfs_getattr)
> > > > > > > > +BTF_ID(func, filp_close)
> > > > > > > > +BTF_WHITELIST_END(btf_whitelist_d_path)
> > > > > > >
> > > > > > > Oh, so that's why you added btf_ids.c. Do you think centralizing all
> > > > > > > those BTF ID lists in one file is going to be more convenient? I lean
> > > > > > > towards keeping them closer to where they are used, as it was with all
> > > > > > > those helper BTF IDS. But I wonder what others think...
> > > > > >
> > > > > > either way works for me, but then BTF_ID_* macros needs to go
> > > > > > to include/linux/btf_ids.h header right?
> > > > > >
> > > > >
> > > > > given it's internal API, I'd probably just put it in
> > > > > include/linux/btf.h or include/linux/bpf.h, don't think we need extra
> > > > > header just for these
> > > >
> > > > actually, I might end up with extra header, so it's possible
> > > > to add selftest for this
> > > >
> > >
> > > How does extra header help with selftest?
> >
> > to create binary with various lists defined like we do in kernel
> > using the same macros..  and check they are properly made/sorted
> >
> 
> So the problem here is that selftests don't have access to internal
> (non-UAPI) linux/bpf.h header, right? Ok, that's a fair point.

hm, how about we keep tools/include/linux/btf_ids.h copy
like we do for other kernel headers

jirka