Re: [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user()

[Linus Torvalds]

On Sun, Mar 29, 2020 at 11:32 AM David Laight <David.Laight@xxxxxxxxxx> wrote:
>
> Can't you simplify that by using the =d constraint rather
> than relying on a asm register variable.

No, because that asm register variable can be 64-bit.

Which on x86-32 isn't "=d". It's "%edx:%ecx".

The asm register variable thing handles that automatically, but "=d" would not.

                Linus