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Date:   Mon, 19 Nov 2018 04:48:46 +0100
From:   Willy Tarreau <w@1wt.eu>
To:     Tim Chen <tim.c.chen@linux.intel.com>
Cc:     Jiri Kosina <jikos@kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Andi Kleen <ak@linux.intel.com>,
        Casey Schaufler <casey.schaufler@intel.com>,
        Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
        the arch/x86 maintainers <x86@kernel.org>,
        stable@vger.kernel.org
Subject: Re: STIBP by default.. Revert?
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On Sun, Nov 18, 2018 at 02:40:28PM -0800, Tim Chen wrote:
> Tasks that want extra security will enable that via prctl interface or
> making themselves non-dumpable.

Well, you need to be careful regarding the last part of your option
above, because a number of network daemons become non-dumpable by
executing setuid() at boot, and certainly don't want to suffer a
performance loss as a side effect of wanting to become "normally"
secure. I'd suggest to use the prctl only so that it doesn't
randomly hit innocent applications that would only have as a last
resort to turn off reasonable security features to avoid this impact.

Regards,
Willy