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Date:   Thu, 14 May 2020 11:32:57 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Andy Lutomirski <luto@kernel.org>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
        "Paul E. McKenney" <paulmck@kernel.org>,
        Alexandre Chartre <alexandre.chartre@oracle.com>,
        Frederic Weisbecker <frederic@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Petr Mladek <pmladek@suse.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        Brian Gerst <brgerst@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Will Deacon <will@kernel.org>
Subject: Re: [patch V4 part 4 02/24] x86/int3: Avoid atomic instrumentation
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 <20200505135313.517429268@linutronix.de>
 <CALCETrXVQsdPafvH56_nF+CKU94wgq-T71=EB6eSBnz70Cd0Rw@mail.gmail.com>
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On Wed, May 13, 2020 at 09:57:52PM -0700, Andy Lutomirski wrote:
> On Tue, May 5, 2020 at 7:15 AM Thomas Gleixner <tglx@linutronix.de> wrote:
> >
> > From: Peter Zijlstra <peterz@infradead.org>
> >
> > Use arch_atomic_*() and READ_ONCE_NOCHECK() to ensure nothing untoward
> > creeps in and ruins things.
> >
> > That is; this is the INT3 text poke handler, strictly limit the code
> > that runs in it, lest it inadvertenly hits yet another INT3.
> 
> 
> Acked-by: Andy Lutomirski <luto@kernel.org>
> 
> Does objtool catch this error?

It does not. I'll put it on the (endless) todo list..