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Date:   Wed, 31 Aug 2022 08:40:43 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     kernel test robot <lkp@intel.com>
Cc:     Kees Cook <keescook@chromium.org>, llvm@lists.linux.dev,
        kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
        Arnd Bergmann <arnd@arndb.de>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: powerpc-linux-objdump: Warning: Unrecognized form: 0x23
Message-ID: <Yw+A+0BY26l0AC5j@dev-arch.thelio-3990X>
References: <202208311414.4OPuYS9K-lkp@intel.com>
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In-Reply-To: <202208311414.4OPuYS9K-lkp@intel.com>
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On Wed, Aug 31, 2022 at 02:52:36PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   dcf8e5633e2e69ad60b730ab5905608b756a032f
> commit: f9b3cd24578401e7a392974b3353277286e49cee Kconfig.debug: make DEBUG_INFO selectable from a choice
> date:   5 months ago
> config: powerpc-buildonly-randconfig-r003-20220830 (https://download.01.org/0day-ci/archive/20220831/202208311414.4OPuYS9K-lkp@intel.com/config)
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c7df82e4693c19e3fd2e25c83eb04d9deb7b7b59)
> reproduce (this is a W=1 build):
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # install powerpc cross compiling tool for clang build
>         # apt-get install binutils-powerpc-linux-gnu
>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f9b3cd24578401e7a392974b3353277286e49cee
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout f9b3cd24578401e7a392974b3353277286e49cee
>         # save the config file
>         mkdir build_dir && cp config build_dir/.config
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=powerpc SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> powerpc-linux-objdump: Warning: Unrecognized form: 0x23

Given this is clang 16.0.0 with
CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT=y, which uses DWARF5 by
default instead of DWARF4, it looks like older binutils not
understanding DWARF5. What version of binutils is being used by the bot?
CONFIG_DEBUG_INFO_DWARF5 requires 2.35.2, it seems like it might be
worth trying to extend those dependencies to
CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT to avoid issues like this,
especially in lieu of Nick's series here, which is already codifying the
implicit default DWARF version of the compiler.

https://lore.kernel.org/20220826181035.859042-1-ndesaulniers@google.com/

Cheers,
Nathan