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Date:   Wed, 19 Jun 2019 13:23:50 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Miroslav Benes <mbenes@suse.cz>
Cc:     Jessica Yu <jeyu@kernel.org>, linux-kernel@vger.kernel.org,
        jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com,
        rostedt@goodmis.org, ast@kernel.org, daniel@iogearbox.net
Subject: Re: [RFC][PATCH] module: Propagate MODULE_STATE_COMING notifier
 errors
Message-ID: <20190619112350.GN3419@hirez.programming.kicks-ass.net>
References: <20190617090335.GX3436@hirez.programming.kicks-ass.net>
 <alpine.LSU.2.21.1906191251380.23337@pobox.suse.cz>
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On Wed, Jun 19, 2019 at 01:12:12PM +0200, Miroslav Benes wrote:
> > @@ -3780,7 +3781,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
> >  
> >  	err = prepare_coming_module(mod);
> >  	if (err)
> > -		goto bug_cleanup;
> > +		goto coming_cleanup;
> 
> Not good. klp_module_going() is not prepared to be called without 
> klp_module_coming() succeeding. "Funny" things might happen.

Bah, I did look at that but failed to spot it :/

> So it calls for more fine-grained error handling.

Another approach that I considered was trying to re-iterate the notifier
list up until the point we got, but that was fairly non-trivial and
needed changes to the notifier crud itself.

I'll try again.