Re: [PATCH v4 1/1] scsi: ufs: core: add device level exception support

[Bart Van Assche]

On 3/25/25 6:15 PM, Bao D. Nguyen wrote:
> The existing "struct utp_upiu_query_v4_0" probably has a bug in it. It 
> does not use the  __attribute__((__packed__)) attribute. The compiler is 
> free to add padding in this structure, resulting in the read attribute 
> value being incorrect. I plan to provide a separate patch to fix this 
> issue.

Adding __attribute__((__packed__)) or __packed to data structures that
don't need it is not an improvement but is a change that makes
processing slower on architectures that do not support unaligned
accesses. Instead of adding __packed to data structures in their
entirety, only add it to those members that need it and check the
structure size as follows:

static_assert(sizeof(...) == ...);

Thanks,

Bart.