Re: [PATCH 08/16] mm/unicore32: use vm_flags_t for vma flags

From: Guan Xuetao <gxt@mprc.pku.edu.cn>
To: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 08/16] mm/unicore32: use vm_flags_t for vma flags
Date: Tue, 27 Mar 2012 11:38:06 +0800	[thread overview]
Message-ID: <4F71361E.1000802@mprc.pku.edu.cn> (raw)
In-Reply-To: <20120321065645.13852.83925.stgit@zurg>

On 03/21/2012 02:56 PM, Konstantin Khlebnikov wrote:
> The same magic like in arm: assembler code wants to test VM_EXEC,
> but for big-endian we should get upper word for this.
>
> Signed-off-by: Konstantin Khlebnikov<khlebnikov@openvz.org>
> Cc: Guan Xuetao<gxt@mprc.pku.edu.cn>
> ---
>   arch/unicore32/kernel/asm-offsets.c |    6 +++++-
>   arch/unicore32/mm/fault.c           |    2 +-
>   2 files changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/unicore32/kernel/asm-offsets.c b/arch/unicore32/kernel/asm-offsets.c
> index ffcbe75..e3199b5 100644
> --- a/arch/unicore32/kernel/asm-offsets.c
> +++ b/arch/unicore32/kernel/asm-offsets.c
> @@ -87,9 +87,13 @@ int main(void)
>   	DEFINE(S_FRAME_SIZE,	sizeof(struct pt_regs));
>   	BLANK();
>   	DEFINE(VMA_VM_MM,	offsetof(struct vm_area_struct, vm_mm));
> +#if defined(CONFIG_CPU_BIG_ENDIAN)&&  (NR_VMA_FLAGS>  32)
> +	DEFINE(VMA_VM_FLAGS,	offsetof(struct vm_area_struct, vm_flags) + 4);
> +#else
CONFIG_CPU_BIG/LITTLE_ENDIAN is defined only in some archs, and not 
supported by unicore32.

>   	DEFINE(VMA_VM_FLAGS,	offsetof(struct vm_area_struct, vm_flags));
> +#endif
>   	BLANK();
> -	DEFINE(VM_EXEC,		VM_EXEC);
> +	DEFINE(VM_EXEC,		(__force unsigned int)VM_EXEC);
Is this check useful for asm-offsets.h?

>   	BLANK();
>   	DEFINE(PAGE_SZ,		PAGE_SIZE);
>   	BLANK();
> diff --git a/arch/unicore32/mm/fault.c b/arch/unicore32/mm/fault.c
> index 283aa4b..9137996 100644
> --- a/arch/unicore32/mm/fault.c
> +++ b/arch/unicore32/mm/fault.c
> @@ -158,7 +158,7 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
>    */
>   static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma)
>   {
> -	unsigned int mask = VM_READ | VM_WRITE | VM_EXEC;
> +	vm_flags_t mask = VM_READ | VM_WRITE | VM_EXEC;

I am confused  for the type of vm_flags in vm_area_struct being 
'unsigned long',  not vm_flags_t.

Regards,

Guan Xuetao