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From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: "Andrii Nakryiko" <andrii.nakryiko@gmail.com>,
	bpf <bpf@vger.kernel.org>, "Alexei Starovoitov" <ast@kernel.org>,
	"Daniel Borkmann" <daniel@iogearbox.net>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Martin KaFai Lau" <kafai@fb.com>,
	"Song Liu" <songliubraving@fb.com>, "Yonghong Song" <yhs@fb.com>,
	"Jesper Dangaard Brouer" <brouer@redhat.com>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>,
	Networking <netdev@vger.kernel.org>
Subject: Re: [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls
Date: Tue, 31 Aug 2021 19:59:31 -0700	[thread overview]
Message-ID: <CAADnVQ+yCv14f6=yCgqZJJxqjC+J18ex32j03q6N_JL_ohovzA@mail.gmail.com> (raw)
In-Reply-To: <20210901022701.g7nzkmm6lo7jf3wd@apollo.localdomain>

On Tue, Aug 31, 2021 at 7:27 PM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
> > > @@ -5327,6 +5340,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
> > >                         ext = &obj->externs[relo->sym_off];
> > >                         insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
> > >                         insn[0].imm = ext->ksym.kernel_btf_id;
> > > +                       insn[0].off = ext->ksym.offset;
> >
> > Just a few lines above we use insn[1].imm =
> > ext->ksym.kernel_btf_obj_fd; for EXT_KSYM (for variables). Why are you
> > inventing a new form if we already have a pretty consistent pattern?
> >
>
> That makes sense. This is all new to me, so I went with what was described in
> e6ac2450d6de (bpf: Support bpf program calling kernel function), but I'll rework
> it to encode the btf fd like that in the next spin. It also makes the everything
> far simpler.

Hmm. kfunc call is a call insn. There is no imm[1].

  reply	other threads:[~2021-09-01  2:59 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-30 17:34 [PATCH bpf-next RFC v1 0/8] Support kernel module function calls from eBPF Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 1/8] bpf: Introduce BPF support for kernel module function calls Kumar Kartikeya Dwivedi
2021-08-30 20:01   ` Alexei Starovoitov
2021-08-30 20:03   ` kernel test robot
2021-08-30 22:19   ` kernel test robot
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 2/8] bpf: Be conservative during verification for invalid kfunc calls Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 3/8] libbpf: Support kernel module function calls Kumar Kartikeya Dwivedi
2021-09-01  0:55   ` Andrii Nakryiko
2021-09-01  2:27     ` Kumar Kartikeya Dwivedi
2021-09-01  2:59       ` Alexei Starovoitov [this message]
2021-09-01  3:38         ` Andrii Nakryiko
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 4/8] libbpf: Resolve invalid kfunc calls with imm = 0, off = 0 Kumar Kartikeya Dwivedi
2021-09-01  0:35   ` Andrii Nakryiko
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 5/8] tools: Allow specifying base BTF file in resolve_btfids Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 6/8] bpf: btf: Introduce helpers for dynamic BTF set registration Kumar Kartikeya Dwivedi
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 7/8] bpf: enable TCP congestion control kfunc from modules Kumar Kartikeya Dwivedi
2021-08-31  0:16   ` kernel test robot
2021-09-01  0:48   ` Andrii Nakryiko
2021-08-30 17:34 ` [PATCH bpf-next RFC v1 8/8] bpf, selftests: Add basic test for module kfunc call Kumar Kartikeya Dwivedi
2021-08-30 20:07   ` Alexei Starovoitov

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