[U-Boot] [PATCH 1/1] efi: fix memory calculation overflow on 32-bit systems

[Heinrich Schuchardt]

On 4/9/19 10:58 PM, Patrick Wildt wrote:
> Hi,
>
> There are Cubox-i machines out there with nearly 4 GiB of RAM.  The
> RAM starts at 0x10000000 with a size of 0xf0000000.  Thus the end
> of RAM is at 0x100000000.  This overflows a 32-bit integer, which
> should be fine since in the EFI memory code the variables used are
> all 64-bit with a fixed size.  Unfortunately EFI_PAGE_MASK, which is
> used in the EFI memory code to remove the lower bits, is based on
> the EFI_PAGE_SIZE macro which, uses 1UL with a shift.  This means
> the resulting mask is UL, which is only 32-bit on ARMv7.  Use ULL to
> make sure that even on 32-bit platforms we use a 64-bit long mask.
> Without this there will be no memory available in the EFI memory map
> and bootefi will fail allocating pages.
>
> Best regards,
> Patrick

We are using `& ~EFI_PAGE_MASK` in multiplaces for 64bit operations. So
it makes sense to use a 64bit value.

Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

>
> diff --git a/include/efi.h b/include/efi.h
> index d98441ab19d..3c9d20f8c0b 100644
> --- a/include/efi.h
> +++ b/include/efi.h
> @@ -190,7 +190,7 @@ enum efi_mem_type {
>  #define EFI_MEM_DESC_VERSION	1
>
>  #define EFI_PAGE_SHIFT		12
> -#define EFI_PAGE_SIZE		(1UL << EFI_PAGE_SHIFT)
> +#define EFI_PAGE_SIZE		(1ULL << EFI_PAGE_SHIFT)
>  #define EFI_PAGE_MASK		(EFI_PAGE_SIZE - 1)
>
>  struct efi_mem_desc {
>