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Date:   Fri, 15 Jan 2021 12:13:42 -0800
From:   Fangrui Song <maskray@google.com>
To:     Anders Roxell <anders.roxell@linaro.org>
Cc:     Nathan Chancellor <natechancellor@gmail.com>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Nick Desaulniers <ndesaulniers@google.com>,
        linux-mips@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        stable@vger.kernel.org
Subject: Re: [PATCH] mips: vdso: fix DWARF2 warning
Message-ID: <20210115201342.76nssqtbs4kttgts@google.com>
References: <20210115191330.2319352-1-anders.roxell@linaro.org>
 <20210115192803.GA3828660@ubuntu-m3-large-x86>
 <CADYN=9Kt597LsfW=Aq6v+kWr+ja+55_+Z3s5mFaJULa+9J4EfA@mail.gmail.com>
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On 2021-01-15, Anders Roxell wrote:
>On Fri, 15 Jan 2021 at 20:28, Nathan Chancellor
><natechancellor@gmail.com> wrote:
>>
>> On Fri, Jan 15, 2021 at 08:13:30PM +0100, Anders Roxell wrote:
>> > When building mips tinyconifg the following warning show up
>> >
>> > make --silent --keep-going --jobs=8 O=/home/anders/src/kernel/next/out/builddir ARCH=mips CROSS_COMPILE=mips-linux-gnu- HOSTCC=clang CC=clang
>> > /srv/src/kernel/next/arch/mips/vdso/elf.S:14:1: warning: DWARF2 only supports one section per compilation unit
>> > .pushsection .note.Linux, "a",@note ; .balign 4 ; .long 2f - 1f ; .long 4484f - 3f ; .long 0 ; 1:.asciz "Linux" ; 2:.balign 4 ; 3:
>> > ^
>> > /srv/src/kernel/next/arch/mips/vdso/elf.S:34:2: warning: DWARF2 only supports one section per compilation unit
>> >  .section .mips_abiflags, "a"
>> >  ^
>> >
>> > Rework so the mips vdso Makefile adds flag '-no-integrated-as' unless
>> > LLVM_IAS is defined.
>> >
>> > Link: https://github.com/ClangBuiltLinux/linux/issues/1256
>> > Cc: stable@vger.kernel.org # v4.19+
>> > Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
>> > Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
>>
>> I believe this is the better solution:
>>
>> https://lore.kernel.org/r/20210115192622.3828545-1-natechancellor@gmail.com/
>
>Yes, I agree.
>
>Cheers,
>Anders

http://lore.kernel.org/r/20201202010850.jibrjpyu6xgkff5p@google.com
Personally I'd drop DWARF v2 as an option.