framebuffer corruption due to overlapping stp instructions on arm64

[Szabolcs Nagy]

On 03/08/18 08:53, Florian Weimer wrote:
> On 08/03/2018 09:11 AM, Andrew Pinski wrote:
>> Yes fix Links not to use memcpy on the framebuffer.
>> It is undefined behavior to use device memory with memcpy.
> 
> Some (de facto) ABIs require that it is supported, though.  For example, the POWER string functions avoid unaligned loads and stores for this 
> reason because the platform has the same issue with device memory.  And yes, GCC will expand memcpy on POWER to something that is incompatible 
> with device memory. 8-(
> 

i think it's not reasonable to require libc memcpy to work on device memory.

i think if device memory is exposed to regular userspace applications that should be fixed.

> If we don't want people to use memcpy, we probably need to provide a credible alternative.
> 
> Thanks,
> Florian