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Date:   Thu, 6 Sep 2018 20:31:57 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Andy Lutomirski <luto@amacapital.net>
Cc:     Nadav Amit <namit@vmware.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>, X86 ML <x86@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        linux-arch <linux-arch@vger.kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Jiri Kosina <jkosina@suse.cz>,
        Andy Lutomirski <luto@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH v2 0/6] x86/alternatives: text_poke() fixes
Message-ID: <20180906183157.GK24106@hirez.programming.kicks-ass.net>
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On Thu, Sep 06, 2018 at 11:09:23AM -0700, Andy Lutomirski wrote:
> > On Sep 6, 2018, at 10:58 AM, Nadav Amit <namit@vmware.com> wrote:
> > It depends what security you want. Some may consider even the short
> > time-window in which the kernel code is writable from other cores as
> > insufficient for security.
> > 
> > In addition, the set removes the need for remote TLB shootdowns that
> > text_poke() - with this fix - requires.
> > 
> 
> I’m personally in favor of not needing a global broadcast flush to install kprobes.

That's fine. But at that point its an optimization, not a correctness
issue.