From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Shuyi Cheng <chengshuyi@linux.alibaba.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>, Martin Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
john fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>,
Networking <netdev@vger.kernel.org>, bpf <bpf@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH bpf-next v4 0/3] Add btf_custom_path in bpf_obj_open_opts
Date: Thu, 15 Jul 2021 21:49:41 -0700 [thread overview]
Message-ID: <CAEf4BzaDMeZ5+v4enTA6m3OJrQsNXY9G8e9uchhaeQmauTTiiQ@mail.gmail.com> (raw)
In-Reply-To: <1626180159-112996-1-git-send-email-chengshuyi@linux.alibaba.com>
On Tue, Jul 13, 2021 at 5:43 AM Shuyi Cheng
<chengshuyi@linux.alibaba.com> wrote:
>
> This patch set adds the ability to point to a custom BTF for the
> purposes of BPF CO-RE relocations. This is useful for using BPF CO-RE
> on old kernels that don't yet natively support kernel (vmlinux) BTF
> and thus libbpf needs application's help in locating kernel BTF
> generated separately from the kernel itself. This was already possible
> to do through bpf_object__load's attribute struct, but that makes it
> inconvenient to use with BPF skeleton, which only allows to specify
> bpf_object_open_opts during the open step. Thus, add the ability to
> override vmlinux BTF at open time.
>
> Patch #1 adds libbpf changes.
> Patch #2 fixes pre-existing memory leak detected during the code review.
> Patch #3 switches existing selftests to using open_opts for custom BTF.
>
LGTM with some minor things I'll adjust while applying (which I'll
point out in respective patches). So no need to re-send anything.
Thanks.
> Changelog:
> ----------
>
> v3: https://lore.kernel.org/bpf/CAEf4BzY2cdT44bfbMus=gei27ViqGE1BtGo6XrErSsOCnqtVJg@mail.gmail.com/T/#m877eed1d4cf0a1d3352d3f3d6c5ff158be45c542
> v3->v4:
> --- Follow Andrii's suggestion to modify cover letter description.
> --- Delete function bpf_object__load_override_btf.
> --- Follow Dan's suggestion to add fixes tag and modify commit msg to patch #2.
> --- Add pathch #3 to switch existing selftests to using open_opts.
>
> v2: https://lore.kernel.org/bpf/CAEf4Bza_ua+tjxdhyy4nZ8Boeo+scipWmr_1xM1pC6N5wyuhAA@mail.gmail.com/T/#mf9cf86ae0ffa96180ac29e4fd12697eb70eccd0f
> v2->v3:
> --- Load the BTF specified by btf_custom_path to btf_vmlinux_override
> instead of btf_bmlinux.
> --- Fix the memory leak that may be introduced by the second version
> of the patch.
> --- Add a new patch to fix the possible memory leak caused by
> obj->kconfig.
>
> v1: https://lore.kernel.org/bpf/CAEf4BzaGjEC4t1OefDo11pj2-HfNy0BLhs_G2UREjRNTmb2u=A@mail.gmail.com/t/#m4d9f7c6761fbd2b436b5dfe491cd864b70225804
> v1->v2:
> -- Change custom_btf_path to btf_custom_path.
> -- If the length of btf_custom_path of bpf_obj_open_opts is too long,
> return ERR_PTR(-ENAMETOOLONG).
> -- Add `custom BTF is in addition to vmlinux BTF`
> with btf_custom_path field.
>
> Shuyi Cheng (3):
> libbpf: Introduce 'btf_custom_path' to 'bpf_obj_open_opts'
> libbpf: Fix the possible memory leak on error
> selftests/bpf: switches existing selftests to using open_opts for custom BTF
>
> tools/lib/bpf/libbpf.c | 42 +++++++++++++++++-----
> tools/lib/bpf/libbpf.h | 9 ++++-
> .../selftests/bpf/prog_tests/core_autosize.c | 22 ++++++------
> .../testing/selftests/bpf/prog_tests/core_reloc.c | 28 +++++++--------
> 4 files changed, 66 insertions(+), 35 deletions(-)
>
> --
> 1.8.3.1
>
prev parent reply other threads:[~2021-07-16 4:49 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 12:42 [PATCH bpf-next v4 0/3] Add btf_custom_path in bpf_obj_open_opts Shuyi Cheng
2021-07-13 12:42 ` [PATCH bpf-next v4 1/3] libbpf: Introduce 'btf_custom_path' to 'bpf_obj_open_opts' Shuyi Cheng
2021-07-16 4:51 ` Andrii Nakryiko
2021-07-17 1:15 ` Shuyi Cheng
2021-07-13 12:42 ` [PATCH bpf-next v4 2/3] libbpf: Fix the possible memory leak on error Shuyi Cheng
2021-07-13 12:42 ` [PATCH bpf-next v4 3/3] selftests/bpf: Switches existing selftests to using open_opts for custom BTF Shuyi Cheng
2021-07-16 4:53 ` Andrii Nakryiko
2021-07-16 20:27 ` Andrii Nakryiko
2021-07-17 1:39 ` Shuyi Cheng
2021-07-16 4:49 ` Andrii Nakryiko [this message]
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