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Date:   Tue, 22 Oct 2019 14:31:12 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Heiko Carstens <heiko.carstens@de.ibm.com>
Cc:     Josh Poimboeuf <jpoimboe@redhat.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, rostedt@goodmis.org,
        mhiramat@kernel.org, bristot@redhat.com, jbaron@akamai.com,
        torvalds@linux-foundation.org, tglx@linutronix.de,
        mingo@kernel.org, namit@vmware.com, hpa@zytor.com, luto@kernel.org,
        ard.biesheuvel@linaro.org, jeyu@kernel.org
Subject: Re: [PATCH v4 15/16] module: Move where we mark modules RO,X
Message-ID: <20191022123112.GI1800@hirez.programming.kicks-ass.net>
References: <20191018073525.768931536@infradead.org>
 <20191018074634.801435443@infradead.org>
 <20191021135312.jbbxsuipxldocdjk@treble>
 <20191021141402.GI1817@hirez.programming.kicks-ass.net>
 <20191021153425.GB19358@hirez.programming.kicks-ass.net>
 <20191021161135.GD19358@hirez.programming.kicks-ass.net>
 <20191022113116.GA8574@osiris>
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On Tue, Oct 22, 2019 at 01:31:16PM +0200, Heiko Carstens wrote:
> On Mon, Oct 21, 2019 at 06:11:35PM +0200, Peter Zijlstra wrote:
> > On Mon, Oct 21, 2019 at 05:34:25PM +0200, Peter Zijlstra wrote:
> > > On Mon, Oct 21, 2019 at 04:14:02PM +0200, Peter Zijlstra wrote:
> > 
> > > So On IRC Josh suggested we use text_poke() for RELA. Since KLP is only
> > > available on Power and x86, and Power does not have STRICT_MODULE_RWX,
> > > the below should be sufficient.
> > > 
> > > Completely untested...
> > 
> > And because s390 also has: HAVE_LIVEPATCH and STRICT_MODULE_RWX the even
> > less tested s390 bits included below.
> > 
> > Heiko, apologies if I completely wrecked it.
> > 
> > The purpose is to remove module_disable_ro()/module_enable_ro() from
> > livepatch/core.c such that:
> > 
> >  - nothing relies on where in the module loading path module text goes RX.
> >  - nothing ever has writable text
> 
> Given that Steven reported a crash, I assume I can wait until you
> repost a new version of the series, which also includes s390 bits?

His crash is somewhat orthogonal, but yes, I will repost once sorted.