From: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
To: Ingo Molnar <mingo@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>,
Thomas Gleixner <tglx@linutronix.de>, Willy Tarreau <w@1wt.eu>,
linux-kernel@vger.kernel.org, x86@kernel.org,
torvalds@linux-foundation.org
Subject: Re: [PATCH RFC 3/4] x86/pti: don't mark the user PGD with _PAGE_NX.
Date: Mon, 8 Jan 2018 18:25:10 +0000 [thread overview]
Message-ID: <20180108182510.3c6dda34@alans-desktop> (raw)
In-Reply-To: <20180108175028.acwe3glhw4rsvdsx@gmail.com>
> The simplest model is indeed child inheritance tree propagation - plus perhaps the
> ability for a thread to change its *own* PTI status, which obviously doesn't
> create any deep "process lookup" or cross-CPU complications.
>
> ( Note that here I only mean "simple to implement" - we might decide to not offer
> the ABI. )
I still think cgroups are the best model for this. In particular it
naturally fits things like containers, or network facing apps that fork
helpers.
Secondly when you are looking at barrier semantics between client/client
a cgroup is much more natural as a way to group processes together who
don't need to be protected from each other as they are trusting each
other. (Or we could just harcode this based upon ptraceability ?)
Alan
next prev parent reply other threads:[~2018-01-08 18:25 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 16:12 [PATCH RFC 0/4] Per-task PTI activation Willy Tarreau
2018-01-08 16:12 ` [PATCH RFC 1/4] x86/thread_info: add TIF_NOPTI to disable PTI per task Willy Tarreau
2018-01-08 16:57 ` Thomas Gleixner
2018-01-08 17:03 ` Willy Tarreau
2018-01-08 17:14 ` Ingo Molnar
2018-01-08 16:12 ` [PATCH RFC 2/4] x86/arch_prctl: add ARCH_GET_NOPTI and ARCH_SET_NOPTI to enable/disable PTI Willy Tarreau
2018-01-08 16:49 ` Peter Zijlstra
2018-01-08 16:56 ` Willy Tarreau
2018-01-08 17:02 ` Thomas Gleixner
2018-01-08 17:10 ` Willy Tarreau
2018-01-08 17:17 ` Ingo Molnar
2018-01-08 17:26 ` Thomas Gleixner
2018-01-08 17:46 ` Ingo Molnar
2018-01-08 17:05 ` Ingo Molnar
2018-01-08 17:19 ` Peter Zijlstra
2018-01-08 17:26 ` Ingo Molnar
2018-01-08 17:50 ` Borislav Petkov
2018-01-08 17:54 ` Linus Torvalds
2018-01-08 18:22 ` Willy Tarreau
2018-01-08 20:49 ` Thomas Gleixner
2018-01-08 21:03 ` Willy Tarreau
2018-01-08 20:35 ` Willy Tarreau
2018-01-08 16:12 ` [PATCH RFC 3/4] x86/pti: don't mark the user PGD with _PAGE_NX Willy Tarreau
2018-01-08 17:03 ` Dave Hansen
2018-01-08 17:17 ` Willy Tarreau
2018-01-08 17:23 ` Dave Hansen
2018-01-08 17:30 ` Peter Zijlstra
2018-01-08 17:49 ` Willy Tarreau
2018-01-08 17:21 ` Ingo Molnar
2018-01-08 23:05 ` Andy Lutomirski
2018-01-08 23:09 ` Kees Cook
2018-01-09 4:22 ` Willy Tarreau
2018-01-08 17:05 ` Thomas Gleixner
2018-01-08 17:28 ` Dave Hansen
2018-01-08 17:50 ` Ingo Molnar
2018-01-08 18:25 ` Alan Cox [this message]
2018-01-08 18:35 ` Ingo Molnar
2018-01-08 18:35 ` Linus Torvalds
2018-01-08 18:44 ` Dave Hansen
2018-01-08 16:12 ` [PATCH RFC 4/4] x86/entry/pti: don't switch PGD on tasks holding flag TIF_NOPTI Willy Tarreau
2018-01-08 17:11 ` Ingo Molnar
2018-01-08 17:20 ` Dave Hansen
2018-01-08 18:12 ` Willy Tarreau
2018-01-08 23:01 ` Andy Lutomirski
2018-01-08 16:59 ` [PATCH RFC 0/4] Per-task PTI activation Dave Hansen
2018-01-08 17:06 ` Willy Tarreau
2018-01-08 17:17 ` Dave Hansen
2018-01-08 17:13 ` Ingo Molnar
2018-01-09 15:31 ` Eric W. Biederman
2018-01-09 16:02 ` Willy Tarreau
2018-01-09 18:11 ` Zhi Wang
2018-01-09 21:07 ` Eric W. Biederman
2018-01-09 21:57 ` Willy Tarreau
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