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From: Peter Zijlstra <peterz@infradead.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
	x86@kernel.org, pjt@google.com, mbenes@suze.cz, jgross@suse.com,
	linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH 6/6] objtool,x86: Rewrite retpoline thunk calls
Date: Sat, 20 Feb 2021 23:32:21 +0100	[thread overview]
Message-ID: <20210220223221.GB4746@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20210220174101.GA29905@zn.tnic>

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.

I can certainly look at adding the flags thing.

  parent reply	other threads:[~2021-02-20 22:33 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-19 20:43 [RFC][PATCH 0/6] objtool: Optimize !retpoline Peter Zijlstra
2021-02-19 20:43 ` [RFC][PATCH 1/6] objtool: Correctly handle retpoline thunk calls Peter Zijlstra
2021-02-19 20:43 ` [RFC][PATCH 2/6] objtool: Fix static_call list generation Peter Zijlstra
2021-02-19 20:43 ` [RFC][PATCH 3/6] objtool: Rework rebuild_reloc logic Peter Zijlstra
2021-02-19 20:43 ` [RFC][PATCH 4/6] objtool: Add elf_create_undef_symbol() Peter Zijlstra
2021-02-19 20:43 ` [RFC][PATCH 5/6] objtool: Allow archs to rewrite retpolines Peter Zijlstra
2021-02-19 20:43 ` [RFC][PATCH 6/6] objtool,x86: Rewrite retpoline thunk calls Peter Zijlstra
2021-02-19 21:55   ` Josh Poimboeuf
2021-02-19 22:01     ` Peter Zijlstra
2021-02-20  0:39       ` Borislav Petkov
2021-02-20 16:48         ` Peter Zijlstra
2021-02-20 17:41           ` Borislav Petkov
2021-02-20 22:28             ` Peter Zijlstra
2021-02-20 22:51               ` Peter Zijlstra
2021-02-21  9:54                 ` Borislav Petkov
2021-02-20 22:32             ` Peter Zijlstra [this message]
2021-02-21  5:45               ` Jürgen Groß
2021-02-21  9:44                 ` Borislav Petkov

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