Re: [PATCH RFC 3/7] xen: arm: make sure we stay within the memory bank during mm setup

[Julien Grall <julien.grall@linaro.org>]

On 09/17/2013 02:40 AM, Ian Campbell wrote:
> Otherwise if there is a module in another bank we can run off the end.
>
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> ---
>   xen/arch/arm/setup.c | 7 ++++++-
>   1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index e58dbc6..94b1362 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -223,8 +223,10 @@ static paddr_t __init next_module(paddr_t s, paddr_t *n)
>               continue;
>           if ( mod_s > lowest )
>               continue;
> +        if ( mod_s > *n )


I needed to look at the call-site to know the meaning of "n".
Can you add a comment above the function to specify that n contains the 
end of the bank/RAM?

> +            continue;
>           lowest = mod_s;
> -        *n = mod_e;
> +        *n = min(*n, mod_e);
>       }
>       return lowest;
>   }
> @@ -450,6 +452,9 @@ static void __init setup_mm(unsigned long dtb_paddr, size_t dtb_size)
>                   e = n = bank_end;
>               }
>
> +            if ( e > bank_end )
> +                e = bank_end;
> +
>               setup_xenheap_mappings(s>>PAGE_SHIFT, (e-s)>>PAGE_SHIFT);
>
>               xenheap_mfn_end = e;
>


-- 
Julien Grall