Re: [PATCH v4 mips-next 1/7] MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section

From: Nathan Chancellor <natechancellor@gmail.com>
To: Alexander Lobakin <alobakin@pm.me>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Fangrui Song <maskray@google.com>,
	Huacai Chen <chenhuacai@kernel.org>,
	Pei Huang <huangpei@loongson.cn>,
	Jiaxun Yang <jiaxun.yang@flygoat.com>,
	Sami Tolvanen <samitolvanen@google.com>,
	Ingo Molnar <mingo@kernel.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	Corey Minyard <cminyard@mvista.com>,
	linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org, stable@vger.kernel.org,
	clang-built-linux@googlegroups.com
Subject: Re: [PATCH v4 mips-next 1/7] MIPS: vmlinux.lds.S: add missing PAGE_ALIGNED_DATA() section
Date: Fri, 8 Jan 2021 14:10:48 -0700	[thread overview]
Message-ID: <20210108211048.GA2547542@ubuntu-m3-large-x86> (raw)
In-Reply-To: <20210107123428.354231-1-alobakin@pm.me>

On Thu, Jan 07, 2021 at 12:34:47PM +0000, Alexander Lobakin wrote:
> MIPS uses its own declaration of rwdata, and thus it should be kept
> in sync with the asm-generic one. Currently PAGE_ALIGNED_DATA() is
> missing from the linker script, which emits the following ld
> warnings:
> 
> mips-alpine-linux-musl-ld: warning: orphan section
> `.data..page_aligned' from `arch/mips/kernel/vdso.o' being placed
> in section `.data..page_aligned'
> mips-alpine-linux-musl-ld: warning: orphan section
> `.data..page_aligned' from `arch/mips/vdso/vdso-image.o' being placed
> in section `.data..page_aligned'
> 
> Add the necessary declaration, so the mentioned structures will be
> placed in vmlinux as intended:
> 
> ffffffff80630580 D __end_once
> ffffffff80630580 D __start___dyndbg
> ffffffff80630580 D __start_once
> ffffffff80630580 D __stop___dyndbg
> ffffffff80634000 d mips_vdso_data
> ffffffff80638000 d vdso_data
> ffffffff80638580 D _gp
> ffffffff8063c000 T __init_begin
> ffffffff8063c000 D _edata
> ffffffff8063c000 T _sinittext
> 
> ->
> 
> ffffffff805a4000 D __end_init_task
> ffffffff805a4000 D __nosave_begin
> ffffffff805a4000 D __nosave_end
> ffffffff805a4000 d mips_vdso_data
> ffffffff805a8000 d vdso_data
> ffffffff805ac000 D mmlist_lock
> ffffffff805ac080 D tasklist_lock
> 
> Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
> Cc: stable@vger.kernel.org # 4.4+
> Signed-off-by: Alexander Lobakin <alobakin@pm.me>
> Reviewed-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

> ---
>  arch/mips/kernel/vmlinux.lds.S | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/mips/kernel/vmlinux.lds.S b/arch/mips/kernel/vmlinux.lds.S
> index 5e97e9d02f98..83e27a181206 100644
> --- a/arch/mips/kernel/vmlinux.lds.S
> +++ b/arch/mips/kernel/vmlinux.lds.S
> @@ -90,6 +90,7 @@ SECTIONS
>  
>  		INIT_TASK_DATA(THREAD_SIZE)
>  		NOSAVE_DATA
> +		PAGE_ALIGNED_DATA(PAGE_SIZE)
>  		CACHELINE_ALIGNED_DATA(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
>  		READ_MOSTLY_DATA(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
>  		DATA_DATA
> -- 
> 2.30.0
> 
>