Re: [RFC][PATCH 6/6] objtool,x86: Rewrite retpoline thunk calls

From: Jürgen Groß
Date: Sun Feb 21 2021 - 00:47:49 EST


On 20.02.21 23:32, Peter Zijlstra wrote:
On Sat, Feb 20, 2021 at 06:41:01PM +0100, Borislav Petkov wrote:
- if we had negative alternatives objtool doesn't need to actually
rewrite code in this case. It could simply emit alternative entries
and call it a day.

I don't mind the negative alt per se - I mind the implementation I saw.
I'm sure we can come up with something nicer, like, for example, struct
alt_instr.flags to denote that this feature is a NOT feature.

So you don't like the ~ or - on cpuid? ISTR we talked about
alt_instr::flags before, but Google isn't playing ball today so I can't
seem to find it.

If you want I can cook up a patch and include it in my paravirt
cleanup series.

Juergen

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