From: Andi Kleen <andi@firstfloor.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andi Kleen <andi@firstfloor.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
X86 ML <x86@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
ilya.enkovich@intel.com
Subject: Re: [PATCH 3.19 3/3] x86, mpx: Change the MPX enable/disable API to arch_prctl
Date: Tue, 6 Jan 2015 22:39:00 +0100 [thread overview]
Message-ID: <20150106213900.GX2915@two.firstfloor.org> (raw)
In-Reply-To: <CALCETrUpR6ZCBSXdbY232inK=LaXLK0LAssqUt+r8DAn9=xjJg@mail.gmail.com>
On Tue, Jan 06, 2015 at 01:34:56PM -0800, Andy Lutomirski wrote:
> On Tue, Jan 6, 2015 at 1:22 PM, Andi Kleen <andi@firstfloor.org> wrote:
> >> Given that it doesn't seen to have been committed yet, I'm not too
> >> worried about compatibility. And "prctl (43)" doesn't actually seem a
> >> whole lot better than "syscall(SYS_arch_prctl, ARCH_ENABLE_MPX, 0)"
> >
> > This would actually fail with the EINVAL change you requested.
> >
>
> So the libmpx code needs to change anyway, then, right? I really
> don't think we should accept garbage in the extra prctl slots just
> because uncommitted code somewhere fails to initialize them.
Yes it would.
I think that is why most prctls don't do it. After all if you need a new
field you can just add another one. I usually added the checks in the
ones I added, but I can see why not doing it.
-Andi
next prev parent reply other threads:[~2015-01-06 21:39 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-30 0:52 [PATCH 3.19 0/3] Possible MPX improvements for 3.19 Andy Lutomirski
2014-12-30 0:52 ` [PATCH 3.19 1/3] x86, mpx: Check user mode bitness correctly when decoding instructions Andy Lutomirski
2015-01-07 17:22 ` Dave Hansen
2015-01-12 22:48 ` Andy Lutomirski
2014-12-30 0:52 ` [PATCH 3.19 2/3] x86, mpx: Short-circuit the instruction decoder for unexpected opcodes Andy Lutomirski
2014-12-30 0:58 ` Andy Lutomirski
2014-12-30 0:52 ` [PATCH 3.19 3/3] x86, mpx: Change the MPX enable/disable API to arch_prctl Andy Lutomirski
2015-01-02 7:53 ` Dave Hansen
2015-01-05 20:42 ` Andi Kleen
2015-01-05 21:18 ` Dave Hansen
2015-01-05 23:04 ` Andy Lutomirski
2015-01-05 23:10 ` Dave Hansen
2015-01-05 23:22 ` Andy Lutomirski
2015-01-06 4:04 ` Andi Kleen
2015-01-06 5:59 ` Andy Lutomirski
2015-01-06 17:48 ` Dave Hansen
2015-01-06 18:06 ` Andy Lutomirski
2015-01-06 18:30 ` Dave Hansen
2015-01-06 18:41 ` Andy Lutomirski
2015-01-06 18:54 ` Dave Hansen
2015-01-06 19:16 ` Andi Kleen
2015-01-06 19:51 ` Andy Lutomirski
2015-01-06 21:22 ` Andi Kleen
2015-01-06 21:34 ` Andy Lutomirski
2015-01-06 21:39 ` Andi Kleen [this message]
2015-01-12 10:34 ` Enkovich, Ilya
2015-01-07 23:18 ` Dave Hansen
2015-01-07 23:24 ` Andy Lutomirski
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