[PATCH] ARM: nommu: avoid mapping vectors page when !CONFIG_MMU

Greg Ungerer gerg at snapgear.com
Tue Jan 11 07:33:09 EST 2011


Hi Will,

On 11/01/11 22:02, Will Deacon wrote:
> When running without an MMU, we do not need to install a mapping for the
> vectors page. Attempting to do so causes a compile-time error because
> install_special_mapping is not defined.
>
> This patch adds compile-time guards to the vector mapping functions
> so that we can build nommu configurations once more.
>
> Cc: Greg Ungerer<gerg at uclinux.org>
> Signed-off-by: Will Deacon<will.deacon at arm.com>

I hit this a couple of days ago too, looks good.

Acked-by: Greg Ungerer <gerg at uclinux.org>

Regards
Greg


>   arch/arm/kernel/process.c |    2 ++
>   1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
> index e76fcaa..94bbedb 100644
> --- a/arch/arm/kernel/process.c
> +++ b/arch/arm/kernel/process.c
> @@ -483,6 +483,7 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
>   	return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
>   }
>
> +#ifdef CONFIG_MMU
>   /*
>    * The vectors page is always readable from user space for the
>    * atomic helpers and the signal restart code.  Let's declare a mapping
> @@ -503,3 +504,4 @@ const char *arch_vma_name(struct vm_area_struct *vma)
>   {
>   	return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
>   }
> +#endif


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Greg Ungerer  --  Principal Engineer        EMAIL:     gerg at snapgear.com
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