Re: [QUESTION] Will the pahole tar source code with corresponding libbpf submodule codes be released as well in the future?

From: Arnaldo Carvalho de Melo <acme@redhat.com>
To: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: [QUESTION] Will the pahole tar source code with corresponding libbpf submodule codes be released as well in the future?
Date: Thu, 15 Apr 2021 18:02:38 -0300	[thread overview]
Message-ID: <20210415210238.GB21027@redhat.com> (raw)
In-Reply-To: <2de4aad5-fa9e-1c39-3c92-9bb9229d0966@loongson.cn>

Em Thu, Apr 15, 2021 at 12:01:23PM +0800, Tiezhu Yang escreveu:
> (1) tools/bpf/bpftool build failed due to the following reason:
> 
> Error: failed to load BTF from /boot/vmlinux-5.12.0-rc2: No such
> file or directory
> make: *** [Makefile:158: vmlinux.h] Error 2
> 
> (2) When set CONFIG_DEBUG_INFO_BTF=y, failed to generate BTF for vmlinux
> due to pahole is not available
> 
> BTF: .tmp_vmlinux.btf: pahole (pahole) is not available
> Failed to generate BTF for vmlinux
> Try to disable CONFIG_DEBUG_INFO_BTF
> make: *** [Makefile:1197: vmlinux] Error 1
> 
> (3) When build pahole from tar.gz source code, it still failed
> due to no libbpf submodule.

You're getting the tarball from the wrong place, you should get it from:

https://fedorapeople.org/~acme/dwarves/dwarves-1.21.tar.xz

Please read the announcement:

https://lore.kernel.org/bpf/YHRiXNX1JUF2Az0A@kernel.org/

- Arnaldo

> loongson@linux:~$ wget https://git.kernel.org/pub/scm/devel/pahole/pahole.git/snapshot/pahole-1.21.tar.gz
> loongson@linux:~$ tar xf pahole-1.21.tar.gz
> loongson@linux:~$ cd pahole-1.21
> loongson@linux:~/pahole-1.21$ mkdir build
> loongson@linux:~/pahole-1.21$ cd build/
> loongson@linux:~/pahole-1.21/build$ cmake -D__LIB=lib ..
> -- The C compiler identification is GNU 10.2.1
> -- Detecting C compiler ABI info
> -- Detecting C compiler ABI info - done
> -- Check for working C compiler: /usr/bin/cc - skipped
> -- Detecting C compile features
> -- Detecting C compile features - done
> -- Checking availability of DWARF and ELF development libraries
> -- Looking for dwfl_module_build_id in elf
> -- Looking for dwfl_module_build_id in elf - found
> -- Found dwarf.h header: /usr/include
> -- Found elfutils/libdw.h header: /usr/include
> -- Found libdw library: /usr/lib/mips64el-linux-gnuabi64/libdw.so
> -- Found libelf library: /usr/lib/mips64el-linux-gnuabi64/libelf.so
> -- Checking availability of DWARF and ELF development libraries - done
> -- Found ZLIB: /usr/lib/mips64el-linux-gnuabi64/libz.so (found
> version "1.2.11")
> CMake Error at CMakeLists.txt:60 (message):
>   The submodules were not downloaded! GIT_SUBMODULE was turned off
> or failed.
>   Please update submodules and try again.
> 
> -- Configuring incomplete, errors occurred!
> See also "/home/loongson/pahole-1.21/build/CMakeFiles/CMakeOutput.log".
> 
> (4) I notice that the pahole git source code can build successful because
> it will clone libbpf automatically:
> 
> -- Submodule update
> Submodule 'lib/bpf' (https://github.com/libbpf/libbpf) registered
> for path 'lib/bpf'
> Cloning into '/home/loongson/pahole/lib/bpf'...
> Submodule path 'lib/bpf': checked out
> '986962fade5dfa89c2890f3854eb040d2a64ab38'
> -- Submodule update - done
> 
> (5) So Will the pahole tar source code with corresponding libbpf
> submodule codes
> be released as well in the future? just like bcc:
> https://github.com/iovisor/bcc/releases
> https://github.com/iovisor/bcc/commit/708f786e3784dc32570a079f2ed74c35731664ea
> 
> Thanks,
> Tiezhu