Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 06 Jan 2021 20:14:22 +0000
To:     Nathan Chancellor <natechancellor@gmail.com>
From:   Alexander Lobakin <alobakin@pm.me>
Cc:     Alexander Lobakin <alobakin@pm.me>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Kees Cook <keescook@chromium.org>,
        Ingo Molnar <mingo@kernel.org>,
        Fangrui Song <maskray@google.com>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Ralf Baechle <ralf@linux-mips.org>,
        Alex Smith <alex.smith@imgtec.com>,
        Markos Chandras <markos.chandras@imgtec.com>,
        linux-mips@vger.kernel.org, stable@vger.kernel.org,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Reply-To: Alexander Lobakin <alobakin@pm.me>
Subject: Re: [PATCH mips-next 0/4] MIPS: vmlinux.lds.S sections fix & cleanup
Message-ID: <20210106201400.32416-1-alobakin@pm.me>
In-Reply-To: <20210104121729.46981-1-alobakin@pm.me>
References: <20210104121729.46981-1-alobakin@pm.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

From: Nathan Chancellor <natechancellor@gmail.com>
Date: Mon, 4 Jan 2021 17:09:36 -0700

> On Mon, Jan 04, 2021 at 12:18:10PM +0000, Alexander Lobakin wrote:
>> This series hunts the problems discovered after manual enabling of
>> ARCH_WANT_LD_ORPHAN_WARN, notably the missing PAGE_ALIGNED_DATA()
>> section affecting VDSO placement (marked for stable).
>>
>> Compile and runtime tested on MIPS32R2 CPS board with no issues.
>>
>> Alexander Lobakin (4):
>>   MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section
>>   MIPS: vmlinux.lds.S: add ".rel.dyn" to DISCARDS
>>   MIPS: vmlinux.lds.S: add ".gnu.attributes" to DISCARDS
>>   MIPS: select ARCH_WANT_LD_ORPHAN_WARN
>>
>>  arch/mips/Kconfig              | 1 +
>>  arch/mips/kernel/vmlinux.lds.S | 5 ++++-
>>  2 files changed, 5 insertions(+), 1 deletion(-)
>>
>> --
>> 2.30.0
>>
>
> Glad to see ARCH_WANT_LD_ORPHAN_WARN catching on :)
>
> I took this for a spin with clang with malta_kvm_guest_defconfig and I
> only see one section unaccounted for:
>
> $ make -skj"$(nproc)" ARCH=3Dmips CROSS_COMPILE=3Dmipsel-linux-gnu- LLVM=
=3D1 O=3Dout/mips distclean malta_kvm_guest_defconfig all
> ...
> ld.lld: warning: <internal>:(.got) is being placed in '.got'
> ld.lld: warning: <internal>:(.got) is being placed in '.got'
> ld.lld: warning: <internal>:(.got) is being placed in '.got'
>
> Looks like most architectures place it in .got (ia64, nios2, powerpc)
> or .text (arm64).

Addressed in v2, thanks!

> Cheers,
> Nathan

Al