linux-kernel - Re: [PATCH bpf v2 2/2] samples/{bpf,hid}: fix broken vmlinux path for VMLINUX

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: <501166cc-02fe-431c-9258-c2f44227ebc4@illinois.edu>
Date: Wed, 29 Jan 2025 04:06:25 -0600
From: Jinghao Jia <jinghao7@...inois.edu>
To: Benjamin Tissoires <bentiss@...nel.org>,
        Andrii Nakryiko <andrii.nakryiko@...il.com>
Cc: Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Martin KaFai Lau <martin.lau@...ux.dev>,
        Eduard Zingerman
 <eddyz87@...il.com>, Song Liu <song@...nel.org>,
        Yonghong Song <yonghong.song@...ux.dev>,
        John Fastabend <john.fastabend@...il.com>,
        KP Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>,
        Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
        Jiri Kosina <jikos@...nel.org>, Masahiro Yamada <masahiroy@...nel.org>,
        Nicolas Schier <n.schier@....de>, Ruowen Qin <ruqin@...hat.com>,
        bpf@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-input@...r.kernel.org
Subject: Re: [PATCH bpf v2 2/2] samples/{bpf,hid}: fix broken vmlinux path for
 VMLINUX_BTF



On 1/24/25 2:04 PM, Benjamin Tissoires wrote:
> On Jan 24 2025, Andrii Nakryiko wrote:
>> On Thu, Jan 23, 2025 at 12:20 AM Jinghao Jia <jinghao7@...inois.edu> wrote:
>>>
>>> Commit 13b25489b6f8 ("kbuild: change working directory to external
>>> module directory with M=") changed kbuild working directory of bpf and
>>> hid samples to samples/{bpf,hid}, which broke the vmlinux path for
>>> VMLINUX_BTF, as the Makefiles assume the current work directory to be
>>> the kernel output directory and use a relative path (i.e., ./vmlinux):
>>>
>>>   Makefile:316: *** Cannot find a vmlinux for VMLINUX_BTF at any of "  /path/to/linux/samples/bpf/vmlinux", build the kernel or set VMLINUX_BTF like "VMLINUX_BTF=/sys/kernel/btf/vmlinux" or VMLINUX_H variable.  Stop.
>>>
>>> Correctly refer to the kernel output directory using $(objtree).
>>>
>>> Fixes: 13b25489b6f8 ("kbuild: change working directory to external module directory with M=")
>>> Tested-by: Ruowen Qin <ruqin@...hat.com>
>>> Signed-off-by: Jinghao Jia <jinghao7@...inois.edu>
>>> ---
>>>  samples/bpf/Makefile | 2 +-
>>>  samples/hid/Makefile | 2 +-
>>>  2 files changed, 2 insertions(+), 2 deletions(-)
>>>
>>
>> can you please split samples/bpf from samples/hid changes, so we can
>> land samples/bpf fix through bpf-next tree independently from other
>> changes?
> 
> FWIW, I don't mind if this goes through the bpf-next tree all at once.
> 
> Acked-by: Benjamin Tissoires <bentiss@...nel.org>
> 
> Cheers,
> Benjamin
> 

I wonder how we are going to move forward with this fix? Do we want to let
it go through bpf tree at once or split the changes?

Best,
Jinghao

>>
>> pw-bot: cr
>>
>>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>>> index 96a05e70ace3..f5865fbbae62 100644
>>> --- a/samples/bpf/Makefile
>>> +++ b/samples/bpf/Makefile
>>> @@ -307,7 +307,7 @@ $(obj)/$(TRACE_HELPERS): TPROGS_CFLAGS := $(TPROGS_CFLAGS) -D__must_check=
>>>
>>>  VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux))                                \
>>>                      $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)) \
>>> -                    $(abspath ./vmlinux)
>>> +                    $(abspath $(objtree)/vmlinux)
>>>  VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
>>>
>>>  $(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
>>> diff --git a/samples/hid/Makefile b/samples/hid/Makefile
>>> index 69159c81d045..db5a077c77fc 100644
>>> --- a/samples/hid/Makefile
>>> +++ b/samples/hid/Makefile
>>> @@ -164,7 +164,7 @@ $(obj)/hid_surface_dial.o: $(obj)/hid_surface_dial.skel.h
>>>
>>>  VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux))                                \
>>>                      $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)) \
>>> -                    $(abspath ./vmlinux)
>>> +                    $(abspath $(objtree)/vmlinux)
>>>  VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
>>>
>>>  $(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
>>> --
>>> 2.48.1
>>>