Re: [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user()
From: Linus Torvalds
Date: Sun Mar 29 2020 - 14:56:03 EST
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