Re: [Qemu-devel] [PATCH] loader: Fix misaligned member access

[Peter Maydell]

On 23 April 2018 at 15:26, Philippe Mathieu-Daudé <address@hidden> wrote:
>> On 04/23/2018 11:04 AM, Peter Maydell wrote:
>>> On 23 April 2018 at 14:57, Philippe Mathieu-Daudé <address@hidden> wrote:
>>>> On 04/23/2018 12:16 AM, David Gibson wrote:
>>>>> On Sun, Apr 22, 2018 at 11:41:20AM +0100, Peter Maydell wrote:
>>>>>> If we need to do an unaligned load, then ldl_p() is the
>>>>>> right way to do it. (We could also just do
>>>>>>  *addr = ldl_be_p(prop) but we maybe don't want to
>>>>>> bake in knowledge that FDT is big-endian).
>>>>
>>>> Since it is, ldl_be_p() seems the clever/cleaner way indeed, but then we
>>>> assume we know the underlying type of fdt32_t; while using memcpy we
>>>> respect the FDT API.
>>>
>>>  *addr = fdt32_to_cpu(ldl_p(prop));
>>>
>>> is better than a raw memcpy still.
>
> ldl_p() is target-specific, I'd prefer loader code to be target agnostic.
>
> Since FDT is big-endian, are you OK I use, as you suggested,
>
>     *addr = ldq_be_p(prop);
>
> (with a comment about FDT being BE)?

Oops, yes, forgot that ldq_p is the target-endian version.
ldq_he_p() is the "load in host endianness" function, so
   *addr = fdt64_to_cpu(ldq_he_p(prop));

Sorry for the confusion.

-- PMM