Re: [Minios-devel] [PATCH v3 08/43] arm64: fix the wrong mask for to_virt/to_phys

[Julien Grall <julien.grall@xxxxxxx>]

Hi,

On 16/04/18 07:31, Huang Shijie wrote:
> In the arm64, the mask 0xffffffff will truncate the value, and
s/In the/On/

> to_virt/to_phys will get wrong results.
>
> This patch fixes it.
>
> Signed-off-by: Huang Shijie <shijie.huang@xxxxxxx>
> ---
>   include/arm/arch_mm.h | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/arm/arch_mm.h b/include/arm/arch_mm.h
> index c66856c..f77a210 100644
> --- a/include/arm/arch_mm.h
> +++ b/include/arm/arch_mm.h
> @@ -15,8 +15,8 @@ extern paddr_t physical_address_offset;
>   
>   #define DEF_PAGE_PROT     0
>   
> -#define to_phys(x)                 (((paddr_t)(x)+physical_address_offset) & 0xffffffff)
> -#define to_virt(x)                 ((void *)(((x)-physical_address_offset) & 
> 0xffffffff))
> +#define to_phys(x)                 (((paddr_t)(x)+physical_address_offset) & 
> (~0UL))
While this looks good on arm64, for arm32 unsigned long is not going to 
be enough. So I think you want to use ~(paddr_t)0 to cover the 32-bit case.
> +#define to_virt(x)                 ((void *)(((x)-physical_address_offset) & 
> (~0UL)))
For avoidance of doubt, UL here is fine.

>   
>   #define PFN_UP(x)                  (unsigned long)(((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
>   #define PFN_DOWN(x)                (unsigned long)((x) >> PAGE_SHIFT)
Cheers,

--
Julien Grall

_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel