On Sat, Aug 2, 2025, at 17:23, Hans Zhang wrote:
> On 2025/8/2 02:08, Keith Busch wrote:
>> On Sat, Aug 02, 2025 at 12:54:27AM +0800, Hans Zhang wrote:
>>>
>>> *value = (type)data; \
>>>
>>> And this function. Could it be that I misunderstood something?
>>
>> The above macro retains the caller's type for "value". If the caller
>> passes a "u8 *", the value is deferenced as a u8.
>
> In this macro definition, bus->ops->read needs to ensure the byte order
> of the read, as Lukas mentioned; otherwise, there is also a big-endian
> issue at this location.
No, there is no endianness problem here, the problem with casting
the pointer type like
u32 *value;
*(type *)value = data;
or any variation of that is is that it only writes to the first
few bytes of *value, and that introduces both the observed endianess
problem and possibly worse uninitialized data usage or out-of-bounds
stack access.
Arnd
