Re: [PATCH v3] x86/entry: emit a symbol for register restoring thunk

From: Borislav Petkov
Date: Tue Jan 12 2021 - 06:48:20 EST


On Mon, Jan 11, 2021 at 05:13:16PM -0800, Nick Desaulniers wrote:
> Unconditionally. See
> https://sourceware.org/pipermail/binutils/2021-January/114700.html
> where that flag was rejected and the optimization was adopted as the
> optimization was obvious to GNU binutils developers. So I suspect this
> will become a problem for GNU binutils users as well after the latest
> release that contains
> https://sourceware.org/pipermail/binutils/attachments/20210105/75dd4a9d/attachment-0001.bin.

Aha, thanks for this.

> I can clean that up in v5; The section symbols were not generated then
> stripped; they were simply never generated.

I'd appreciate a more verbose writeup explaining why this is being done,
but written for outsiders who are not necessarily toolchain developers.
So that it is clear months/years from now why this was done. Something
structured like this maybe:

Problem is A.

It happens because of B.

Fix it by doing C.

(Potentially do D).

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette