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From: Rik van Riel <riel@surriel.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	linux-kernel@vger.kernel.org
Cc: x86@kernel.org, "Andy Lutomirski" <luto@kernel.org>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	kvm@vger.kernel.org, "Jason A. Donenfeld" <Jason@zx2c4.com>,
	"Dave Hansen" <dave.hansen@linux.intel.com>
Subject: Re: [PATCH 00/11 v3] x86: load FPU registers on return to userland
Date: Thu, 04 Oct 2018 12:45:08 -0400	[thread overview]
Message-ID: <8ea44ae2bb4844df812ea4c6cb0c00ef12708c51.camel@surriel.com> (raw)
In-Reply-To: <20181004140547.13014-1-bigeasy@linutronix.de>

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On Thu, 2018-10-04 at 16:05 +0200, Sebastian Andrzej Siewior wrote:


> In v3 I dropped that decouple idea. I also learned that the wrpkru
> instruction is not privileged and so caching it in kernel does not
> work.

Wait, so any thread can bypass its memory protection
keys, even if there is a seccomp filter preventing
it from calling the PKRU syscalls?

Is that intended?

Is that simply a hardware limitation, or something
where we can set a flag somewhere to force tasks to
go through the kernel?

-- 
All Rights Reversed.

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  parent reply	other threads:[~2018-10-04 16:45 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-04 14:05 [PATCH 00/11 v3] x86: load FPU registers on return to userland Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 01/11] x86/entry: remove _TIF_ALLWORK_MASK Sebastian Andrzej Siewior
2018-10-11 16:27   ` Borislav Petkov
2018-10-04 14:05 ` [PATCH 02/11] x86/fpu: add (__)make_fpregs_active helpers Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 03/11] x86/fpu: make __raw_xsave_addr() use feature number instead of mask Sebastian Andrzej Siewior
2018-10-11 17:30   ` Christophe de Dinechin
2018-10-18 11:19     ` Sebastian Andrzej Siewior
2018-10-12 15:52   ` Dave Hansen
2018-10-18 11:17     ` Sebastian Andrzej Siewior
2018-10-18 11:21       ` Sebastian Andrzej Siewior
2018-10-17 10:01   ` Borislav Petkov
2018-10-18 11:48     ` Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 04/11] x86/fpu: eager switch PKRU state Sebastian Andrzej Siewior
2018-10-12 17:51   ` Dave Hansen
2018-10-12 18:09     ` Andy Lutomirski
2018-10-12 19:44       ` Dave Hansen
2018-10-18 16:13     ` Sebastian Andrzej Siewior
2018-10-18 17:50       ` Dave Hansen
2018-10-04 14:05 ` [PATCH 05/11] x86/fpu: set PKRU state for kernel threads Sebastian Andrzej Siewior
2018-10-12 17:54   ` Dave Hansen
2018-10-12 18:02     ` Andy Lutomirski
2018-10-18 16:26       ` Sebastian Andrzej Siewior
2018-10-18 16:48         ` Andy Lutomirski
2018-10-18 17:47           ` Dave Hansen
2018-10-18 18:25           ` Sebastian Andrzej Siewior
2018-10-18 20:46             ` Andy Lutomirski
2018-10-18 20:56               ` Dave Hansen
2018-10-18 21:24                 ` Sebastian Andrzej Siewior
2018-10-18 21:58                   ` Andy Lutomirski
2018-10-19  7:44               ` Paolo Bonzini
2018-10-19 16:59                 ` Andy Lutomirski
2018-10-19 17:01                   ` Dave Hansen
2018-10-19 17:37                     ` Andy Lutomirski
2018-10-19 18:26                       ` Dave Hansen
2018-10-04 14:05 ` [PATCH 06/11] x86/pkeys: make init_pkru_value static Sebastian Andrzej Siewior
2018-10-12 17:55   ` Dave Hansen
2018-10-04 14:05 ` [PATCH 07/11] x86/pkeys: Drop the preempt-disable section Sebastian Andrzej Siewior
2018-10-12 17:58   ` Dave Hansen
2018-10-12 18:07     ` Andy Lutomirski
2018-10-12 20:26       ` Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 08/11] x86/fpu: Always store the registers in copy_fpstate_to_sigframe() Sebastian Andrzej Siewior
2018-10-11 17:50   ` Christophe de Dinechin
2018-10-11 21:18     ` Andy Lutomirski
2018-10-12 18:15   ` Dave Hansen
2018-11-02 14:42     ` Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 09/11] x86/entry: add TIF_LOAD_FPU Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 10/11] x86/fpu: prepare copy_fpstate_to_sigframe for TIF_LOAD_FPU Sebastian Andrzej Siewior
2018-10-12 19:40   ` Dave Hansen
2018-10-15 15:24     ` Borislav Petkov
2018-11-02 15:44       ` Sebastian Andrzej Siewior
2018-11-02 22:55     ` Sebastian Andrzej Siewior
2018-10-04 14:05 ` [PATCH 11/11] x86/fpu: defer FPU state load until return to userspace Sebastian Andrzej Siewior
2018-10-04 16:14   ` Andy Lutomirski
2018-10-12 20:25     ` Sebastian Andrzej Siewior
2018-10-04 16:45 ` Rik van Riel [this message]
2018-10-04 16:50   ` [PATCH 00/11 v3] x86: load FPU registers on return to userland Andy Lutomirski
2018-10-05 11:55   ` Sebastian Andrzej Siewior

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