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Message-ID: <20160815125214.2727bf88@xhacker>
Date: Mon, 15 Aug 2016 12:52:14 +0800
From: Jisheng Zhang <jszhang@...vell.com>
To: Ard Biesheuvel <ard.biesheuvel@...aro.org>
CC: Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Lorenzo Pieralisi <lorenzo.pieralisi@....com>,
"Kees Cook" <keescook@...omium.org>,
Mark Rutland <mark.rutland@....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 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"?
Thanks,
Jisheng
>
> > Signed-off-by: Jisheng Zhang <jszhang@...vell.com>
> > ---
> > arch/arm64/kernel/kaslr.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
> > index b054691..8ebabc4 100644
> > --- a/arch/arm64/kernel/kaslr.c
> > +++ b/arch/arm64/kernel/kaslr.c
> > @@ -20,8 +20,8 @@
> > #include <asm/pgtable.h>
> > #include <asm/sections.h>
> >
> > -u64 __read_mostly module_alloc_base;
> > -u16 __initdata memstart_offset_seed;
> > +u64 module_alloc_base __read_mostly;
> > +u16 memstart_offset_seed __initdata;
> >
> > static __init u64 get_kaslr_seed(void *fdt)
> > {
> > --
> > 2.8.1
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@...ts.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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