From: Stanislav Fomichev <sdf@fomichev.me>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Stanislav Fomichev <sdf@google.com>,
Network Development <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Subject: Re: [PATCH bpf-next 1/3] bpf: preserve command of the process that loaded the program
Date: Fri, 11 Oct 2019 17:38:19 -0700 [thread overview]
Message-ID: <20191012003819.GK2096@mini-arch> (raw)
In-Reply-To: <CAADnVQLKPLXej_v7ymv3yJakoFLGeQwdZOJ5cZmp7xqOxfebqg@mail.gmail.com>
On 10/11, Alexei Starovoitov wrote:
> On Fri, Oct 11, 2019 at 9:21 AM Stanislav Fomichev <sdf@google.com> wrote:
> >
> > Even though we have the pointer to user_struct and can recover
> > uid of the user who has created the program, it usually contains
> > 0 (root) which is not very informative. Let's store the comm of the
> > calling process and export it via bpf_prog_info. This should help
> > answer the question "which process loaded this particular program".
> >
> > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > ---
> > include/linux/bpf.h | 1 +
> > include/uapi/linux/bpf.h | 2 ++
> > kernel/bpf/syscall.c | 4 ++++
> > 3 files changed, 7 insertions(+)
> >
> > diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> > index 5b9d22338606..b03ea396afe5 100644
> > --- a/include/linux/bpf.h
> > +++ b/include/linux/bpf.h
> > @@ -421,6 +421,7 @@ struct bpf_prog_aux {
> > struct work_struct work;
> > struct rcu_head rcu;
> > };
> > + char created_by_comm[BPF_CREATED_COMM_LEN];
> > };
> >
> > struct bpf_array {
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index a65c3b0c6935..4e883ecbba1e 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -326,6 +326,7 @@ enum bpf_attach_type {
> > #define BPF_F_NUMA_NODE (1U << 2)
> >
> > #define BPF_OBJ_NAME_LEN 16U
> > +#define BPF_CREATED_COMM_LEN 16U
>
> Nack.
> 16 bytes is going to be useless.
> We found it the hard way with prog_name.
> If you want to embed additional debug information
> please use BTF for that.
BTF was my natural choice initially, but then I saw created_by_uid and
thought created_by_comm might have a chance :-)
To clarify, by BTF you mean creating some unused global variable
and use its name as the debugging info? Or there is some better way?
next prev parent reply other threads:[~2019-10-12 0:38 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-11 16:21 [PATCH bpf-next 1/3] bpf: preserve command of the process that loaded the program Stanislav Fomichev
2019-10-11 16:21 ` [PATCH bpf-next 2/3] tools/bpf: sync bpf.h Stanislav Fomichev
2019-10-11 16:21 ` [PATCH bpf-next 3/3] bpftool: print the comm of the process that loaded the program Stanislav Fomichev
2019-10-11 20:19 ` Martin Lau
2019-10-11 20:37 ` Stanislav Fomichev
2019-10-11 21:11 ` Arnaldo Carvalho de Melo
2019-10-11 21:30 ` Stanislav Fomichev
2019-10-12 0:10 ` [PATCH bpf-next 1/3] bpf: preserve command " Alexei Starovoitov
2019-10-12 0:38 ` Stanislav Fomichev [this message]
2019-10-15 21:21 ` debug annotations for bpf progs. Was: " Alexei Starovoitov
2019-10-15 22:14 ` Andrii Nakryiko
2019-10-15 22:24 ` Alexei Starovoitov
2019-10-15 22:33 ` Andrii Nakryiko
2019-10-15 22:48 ` Alexei Starovoitov
2019-10-15 22:26 ` Stanislav Fomichev
2019-10-16 14:01 ` Daniel Borkmann
2019-10-17 16:28 ` Stanislav Fomichev
2019-10-18 6:19 ` Alexei Starovoitov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20191012003819.GK2096@mini-arch \
--to=sdf@fomichev.me \
--cc=alexei.starovoitov@gmail.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=sdf@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).