Re: [patch 02/14] tmpfs: fix regressions from wider use of ZERO_PAGE

Linus Torvalds
2022-04-19T16:42:04Z

On Tue, Apr 19, 2022 at 2:17 AM Borislav Petkov <bp@alien8.de> wrote:
>
> Yap, and I reused your text and expanded it. You made me look at that
> crazy DEFINE_EXTABLE_TYPE_REG macro finally so that I know what it does
> in detail.
>
> So I have the below now, it boots in the guest so it must be perfect.

This looks fine to me.

Although honestly, I'd be even happier without those fancy exception
table tricks. I actually think things would be more legible if we had
explicit error return points that did the

err8:
shrq $3,%rcx
addq %rax,%rcx
err1:
xorl %eax,%eax
RET

things explicitly.

That's perhaps especially true since this whole thing now added a new
- and even more complex - error case with that _ASM_EXTABLE_TYPE_REG.

But I'm ok with the complex version too, I guess.

Linus