linux-kernel - Re: [PATCH 02/29] x86/module: Fix the paravirt vs alternative order

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Message-ID: <20220218232841.xrufb26tgzou2aty@treble>
Date:   Fri, 18 Feb 2022 15:28:41 -0800
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     x86@...nel.org, joao@...rdrivepizza.com, hjl.tools@...il.com,
        andrew.cooper3@...rix.com, linux-kernel@...r.kernel.org,
        ndesaulniers@...gle.com, keescook@...omium.org,
        samitolvanen@...gle.com, mark.rutland@....com,
        alyssa.milburn@...el.com, Juergen Gross <jgross@...e.com>
Subject: Re: [PATCH 02/29] x86/module: Fix the paravirt vs alternative order

On Fri, Feb 18, 2022 at 10:22:46PM +0100, Peter Zijlstra wrote:
> On Fri, Feb 18, 2022 at 12:28:20PM -0800, Josh Poimboeuf wrote:
> > On Fri, Feb 18, 2022 at 05:49:04PM +0100, Peter Zijlstra wrote:
> > > Ever since commit 4e6292114c741 ("x86/paravirt: Add new features for
> > > paravirt patching") there is an ordering dependency between patching
> > > paravirt ops and patching alternatives, the module loader still
> > > violates this.
> > > 
> > > Fixes: 4e6292114c741 ("x86/paravirt: Add new features for paravirt patching")
> > > Cc: Juergen Gross <jgross@...e.com>
> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
> > 
> > Probably a good idea to put the 'para' and 'alt' clauses next to each
> > other and add a comment that the ordering is necessary.
> 
> Can't, retpolines must be in between, but I'll add a comment to check
> alternative.c for ordering constraints.

Ah, even more justification for a comment then ;-)

-- 
Josh