BPF Archive on lore.kernel.org
 help / color / Atom feed
From: KP Singh <kpsingh@chromium.org>
To: Song Liu <songliubraving@fb.com>
Cc: Anton Protopopov <a.s.protopopov@gmail.com>,
	Andrii Nakryiko <andriin@fb.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>, Martin Lau <kafai@fb.com>,
	Yonghong Song <yhs@fb.com>, Networking <netdev@vger.kernel.org>,
	bpf <bpf@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH bpf-next] tools: libbpf: update extended attributes version of bpf_object__open()
Date: Fri, 27 Sep 2019 15:12:02 +0200
Message-ID: <20190927131202.GA18934@chromium.org> (raw)
In-Reply-To: <9EC54605-1911-48B0-B33A-02EC46DEF3DD@fb.com>

On 30-Aug 19:24, Song Liu wrote:
> 
> 
> > On Aug 30, 2019, at 11:53 AM, Anton Protopopov <a.s.protopopov@gmail.com> wrote:
> > 
> > чт, 29 авг. 2019 г. в 16:02, Song Liu <songliubraving@fb.com>:
> >> 
> >> 
> >> 
> >>> On Aug 14, 2019, at 5:03 PM, Anton Protopopov <a.s.protopopov@gmail.com> wrote:
> >>> 
> >> 
> >> [...]
> >> 
> >>> 
> >>> 
> >>> int bpf_object__unload(struct bpf_object *obj)
> >>> diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
> >>> index e8f70977d137..634f278578dd 100644
> >>> --- a/tools/lib/bpf/libbpf.h
> >>> +++ b/tools/lib/bpf/libbpf.h
> >>> @@ -63,8 +63,13 @@ LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
> >>> struct bpf_object;
> >>> 
> >>> struct bpf_object_open_attr {
> >>> -     const char *file;
> >>> +     union {
> >>> +             const char *file;
> >>> +             const char *obj_name;
> >>> +     };
> >>>      enum bpf_prog_type prog_type;
> >>> +     void *obj_buf;
> >>> +     size_t obj_buf_sz;
> >>> };
> >> 
> >> I think this would break dynamically linked libbpf. No?
> > 
> > Ah, yes, sure. What is the right way to make changes which break ABI in libbpf?
> 
> I don't have a good idea here on the top of my head.
> 
> Maybe we need a new struct and/or function for this. 


I incorporated the suggested fixes and sent a new patch for this as we
ran into pretty much the same issue. (i.e. not being able to set
needs_kver / flags).

https://lore.kernel.org/bpf/20190927130834.18829-1-kpsingh@chromium.org/T/#u

- KP

>  
> > 
> > BTW, does the commit ddc7c3042614 ("libbpf: implement BPF CO-RE offset
> > relocation algorithm") which adds a new field to the struct
> > bpf_object_load_attr also break ABI?
> 
> I think this change was in the same release, so it is OK. 
> 
> Thanks,
> Song

      reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-15  0:03 Anton Protopopov
2019-08-29 20:02 ` Song Liu
2019-08-30 18:53   ` Anton Protopopov
2019-08-30 19:24     ` Song Liu
2019-09-27 13:12       ` KP Singh [this message]

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=20190927131202.GA18934@chromium.org \
    --to=kpsingh@chromium.org \
    --cc=a.s.protopopov@gmail.com \
    --cc=andriin@fb.com \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=kafai@fb.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=songliubraving@fb.com \
    --cc=yhs@fb.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

BPF Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/bpf/0 bpf/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 bpf bpf/ https://lore.kernel.org/bpf \
		bpf@vger.kernel.org
	public-inbox-index bpf

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.bpf


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git