linux-kernel - Re: [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read

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Message-ID: <20160815135741.35e60cd1@xhacker>
Date:	Mon, 15 Aug 2016 13:57:41 +0800
From:	Jisheng Zhang <jszhang@...vell.com>
To:	Ard Biesheuvel <ard.biesheuvel@...aro.org>
CC:	Mark Rutland <mark.rutland@....com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
	Kees Cook <keescook@...omium.org>,
	"Catalin Marinas" <catalin.marinas@....com>,
	Will Deacon <will.deacon@....com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of
 __initdata and __read_mostly

Hi Ard,

On Mon, 15 Aug 2016 12:52:14 +0800 Jisheng Zhang wrote:

> Hi Ard,
> 
> On Fri, 12 Aug 2016 14:02:40 +0200 Ard Biesheuvel wrote:
> 
> > Hi Jisheng,
> > 
> > On 12 August 2016 at 10:01, Jisheng Zhang <jszhang@...vell.com> wrote:  
> > > __initdata and __read_mostly should be placed after the variable name
> > > for the variable to be placed in the intended section.
> > >    
> > 
> > Why?  
> 
> include/linux/init.h says something as:
> 
>  * For initialized data:
>  * You should insert __initdata or __initconst between the variable name
>  * and equal sign followed by value, e.g.:
>  *
>  * static int init_variable __initdata = 0;
>  * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
> 
> and examples in gcc manual also put __attribute__ (...) after variable name.
> 
> https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#Common-Variable-Attributes
> 
> Then I grep the source, found most lines (especially arch/arm64/*) put the
> __initdata and __read_mostly after the variable name.
> 
> However, I built the code with three different gcc, the result looks identical
> no matter where these markers put. So the commit msg looks wrong, what about
> changes it as
> 
> "put __initdata and __read_mostly after the variable name
> to keep the style consistent"?

After some consideration, I want to drop this patch in newer version since
it's not a bug, just "style"

Thanks for your reviewing,
Jisheng