From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: martin.lau@linux.dev, bpf <bpf@vger.kernel.org>,
clang-built-linux <llvm@lists.linux.dev>,
"Tomasz Paweł Gajc" <tpgxyz@gmail.com>,
"Masami Hiramatsu" <mhiramat@kernel.org>
Subject: Re: FAILED: load BTF from vmlinux: Invalid argument
Date: Thu, 3 Aug 2023 17:39:38 -0300 [thread overview]
Message-ID: <ZMwQivemlha+fU5i@kernel.org> (raw)
In-Reply-To: <CAKwvOdm9PqNBLSZa_t5b=15cdtKvKq4q8WZr3i77W66m4FRAAQ@mail.gmail.com>
Em Thu, Aug 03, 2023 at 11:02:46AM -0700, Nick Desaulniers escreveu:
> Hi Martin (and BTF/BPF team),
> I've observed 2 user reports with the error from the subject of this email.
> https://github.com/ClangBuiltLinux/linux/issues/1825
> https://bbs.archlinux.org/viewtopic.php?id=284177
>
> Any chance you could take a look at these reports and help us figure
> out what's going wrong here? Nathan and I haven't been able to
> reproduce, but this seems to be affecting OpenMandriva (and Tomasz).
>
> Sounds like perhaps llvm-objcopy vs gnu objcopy might be a relevant detail?
Masami had a problem with new versions of compilers that was solved
with:
------------------------ 8< --------------------------------------------
> To check that please tweak:
>
> ⬢[acme@toolbox perf-tools-next]$ grep DWARF ../build/v6.2-rc5+/.config
> CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y
> # CONFIG_DEBUG_INFO_DWARF4 is not set
> # CONFIG_DEBUG_INFO_DWARF5 is not set
> ⬢[acme@toolbox perf-tools-next]$
>
> i.e. disable CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT and enable
> CONFIG_DEBUG_INFO_DWARF4.
Hm, with CONFIG_DEBUG_INFO_DWARF4, no warning were shown.
LD .tmp_vmlinux.btf
BTF .btf.vmlinux.bin.o
LD .tmp_vmlinux.kallsyms1
And
/ # strings /sys/kernel/btf/vmlinux | wc -l
89921
/ # strings /sys/kernel/btf/vmlinux | grep -w kfree
kfree
It seems the BTF is correctly generated. (with DWARF5, the number of symbols
are about 30000.)
next prev parent reply other threads:[~2023-08-03 20:39 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-03 18:02 FAILED: load BTF from vmlinux: Invalid argument Nick Desaulniers
2023-08-03 20:39 ` Arnaldo Carvalho de Melo [this message]
2023-08-03 20:50 ` Nick Desaulniers
2023-08-03 22:10 ` Alan Maguire
2023-08-04 16:11 ` Nick Desaulniers
2023-08-04 16:41 ` Arnaldo Carvalho de Melo
2023-08-04 22:03 ` Alan Maguire
2023-08-05 15:42 ` Jiri Olsa
2023-08-07 16:05 ` Nick Desaulniers
2023-08-04 8:10 ` Masami Hiramatsu
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