Re: [GIT PULL] x86/asm changes for v5.6

From: Linus Torvalds
Date: Thu Jan 30 2020 - 10:27:51 EST


On Thu, Jan 30, 2020 at 12:51 AM Borislav Petkov <bp@xxxxxxx> wrote:
>
> However, this new version has hit another shortcoming of the
> alternatives - check this out:

[ Branches not getting fixed up ]

Fair enough. Let's not complicate things just to avoid a few nops.

That does make me wonder about RIP-relative addressing in alternatives
too. Particularly anything where we let gcc pick addressing modes. I
guess we don't have any, but maybe this branch issue and possible RIP
addressing is something that objtool could be taught to warn about?

Linus