On Thu, Nov 08, 2018 at 01:22:54PM -0800, Andy Lutomirski wrote:

quoted

quoted

Why are these __packed?  It seems like it'll generate bad code for no
obvious purpose.

That prevents any possibility that the compiler will insert padding, although in
64-bit kernel this should not happen to either struct.  Also all xstate
components here are packed.

They both seem like bugs, perhaps.  As I understand it, __packed
removes padding, but it also forces the compiler to expect the fields
to be unaligned even if they are actually aligned.

How is that? Andy, mind to point where you get that this
attribute forces compiler to make such assumption?