linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Julien Thierry <julien.thierry@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	valentin.schneider@arm.com, Will Deacon <will.deacon@arm.com>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Ingo Molnar <mingo@redhat.com>, James Morse <james.morse@arm.com>,
	Andrew Lutomirski <luto@kernel.org>,
	Brian Gerst <brgerst@gmail.com>, Borislav Petkov <bp@alien8.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>,
	"linux-alpha@vger.kernel.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] sched/x86: Save [ER]FLAGS on context switch
Date: Mon, 18 Feb 2019 16:24:30 -0800	[thread overview]
Message-ID: <CAHk-=wj4Ws1s3iw+w62jcFdnarWhiVxs9zCBjoo7WysxRVZAgQ@mail.gmail.com> (raw)
In-Reply-To: <9e037d68-75e7-1beb-0c9c-33a7ffeced1b@zytor.com>

On Mon, Feb 18, 2019 at 2:31 PM H. Peter Anvin <hpa@zytor.com> wrote:
>
> The question is what "fix it" means. I'm really concerned about AC escapes,
> and everyone else should be, too.

I do think that it might be the right thing to do to add some kind of
WARN_ON_ONCE() for AC being set in various can-reschedule situations.

We'd just have to abstract it sanely. I'm sure arm64 has the exact
same issue with PAN - maybe it saves properly, but the same "we
wouldn't want to go through the scheduler with PAN clear".

On x86, we might as well check DF at the same time as AC.

              Linus

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2019-02-19  0:25 UTC|newest]

Thread overview: 88+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-15 13:58 [PATCH v3 0/4] uaccess: Add unsafe accessors for arm64 Julien Thierry
2019-01-15 13:58 ` [PATCH v3 1/4] arm64: uaccess: Cleanup get/put_user() Julien Thierry
2019-01-15 13:58 ` [PATCH v3 2/4] arm64: uaccess: Implement unsafe accessors Julien Thierry
2019-01-15 13:58 ` [PATCH v3 3/4] uaccess: Check no rescheduling function is called in unsafe region Julien Thierry
2019-01-30 16:58   ` Valentin Schneider
2019-02-04 13:27     ` Julien Thierry
2019-02-11 13:45   ` Ingo Molnar
2019-02-11 13:51     ` Peter Zijlstra
2019-02-12  9:15       ` Julien Thierry
2019-02-13  8:21         ` Ingo Molnar
2019-02-13 10:35         ` Peter Zijlstra
2019-02-13 10:50           ` Julien Thierry
2019-02-13 13:17             ` Peter Zijlstra
2019-02-13 13:20               ` Peter Zijlstra
2019-02-13 14:00               ` Will Deacon
2019-02-13 14:07                 ` Julien Thierry
2019-02-13 14:17                 ` Peter Zijlstra
2019-02-13 14:24                   ` Julien Thierry
2019-02-13 14:40                     ` Peter Zijlstra
2019-02-13 15:08                       ` Peter Zijlstra
2019-02-13 14:25                 ` Peter Zijlstra
2019-02-13 14:39                   ` Julien Thierry
2019-02-13 14:41                     ` Peter Zijlstra
2019-02-13 15:45                       ` Peter Zijlstra
2019-02-13 18:54                         ` Peter Zijlstra
     [not found]                         ` <D61C430D-4321-4114-AB85-671A3C7B8EAE@amacapital.net>
2019-02-13 22:21                           ` Peter Zijlstra
2019-02-13 22:49                             ` Andy Lutomirski
2019-02-14 10:14                               ` [PATCH] sched/x86: Save [ER]FLAGS on context switch Peter Zijlstra
2019-02-14 16:18                                 ` Brian Gerst
2019-02-14 19:34                                   ` Peter Zijlstra
2019-02-15 14:34                                     ` Brian Gerst
2019-02-15 17:18                                     ` Linus Torvalds
2019-02-15 17:40                                       ` Peter Zijlstra
2019-02-15 18:28                                         ` Andy Lutomirski
2019-02-15 23:34                                         ` Peter Zijlstra
2019-02-16  0:21                                           ` Linus Torvalds
2019-02-16 10:32                                             ` Peter Zijlstra
2019-02-16  4:06                                 ` hpa
2019-02-16 10:30                                   ` Peter Zijlstra
2019-02-18 22:30                                     ` H. Peter Anvin
2019-02-19  0:24                                       ` Linus Torvalds [this message]
2019-02-19  2:20                                         ` Andy Lutomirski
2019-02-19  2:46                                           ` H. Peter Anvin
2019-02-19  9:07                                             ` Julien Thierry
2019-02-19  8:53                                         ` Julien Thierry
2019-02-19  9:15                                         ` Peter Zijlstra
2019-02-19  9:19                                           ` Peter Zijlstra
2019-02-19  9:04                                       ` Peter Zijlstra
2019-02-19  9:21                                         ` hpa
2019-02-19  9:44                                         ` Peter Zijlstra
2019-02-19 11:38                                           ` Thomas Gleixner
2019-02-19 11:58                                             ` Peter Zijlstra
2019-02-19 12:48                                         ` Will Deacon
2019-02-20 22:55                                           ` H. Peter Anvin
2019-02-21 12:06                                             ` Julien Thierry
2019-02-21 21:35                                               ` Thomas Gleixner
2019-02-21 22:08                                                 ` Linus Torvalds
2019-02-22 12:58                                                   ` Peter Zijlstra
2019-02-22 18:10                                                   ` Thomas Gleixner
2019-02-22 22:26                                                     ` [RFC][PATCH] objtool: STAC/CLAC validation Peter Zijlstra
2019-02-22 23:34                                                       ` Linus Torvalds
2019-02-23  8:43                                                         ` Peter Zijlstra
2019-02-22 23:39                                                       ` hpa
2019-02-23  8:39                                                         ` Peter Zijlstra
2019-02-25  8:47                                                           ` hpa
2019-02-25 13:21                                                             ` Peter Zijlstra
2019-03-01 15:07                                                               ` Peter Zijlstra
2019-02-25  8:49                                                           ` hpa
2019-02-22 23:55                                                       ` Andy Lutomirski
2019-02-23  8:37                                                         ` Peter Zijlstra
2019-02-23 10:52                                                           ` Peter Zijlstra
2019-02-25 10:51                                                         ` Peter Zijlstra
2019-02-25 11:53                                                           ` Peter Zijlstra
2019-02-25 15:36                                                             ` Andy Lutomirski
2019-02-23  0:34                                                       ` Andy Lutomirski
2019-02-23  1:12                                                         ` Linus Torvalds
2019-02-23  1:16                                                           ` Andy Lutomirski
2019-02-23  1:33                                                             ` Linus Torvalds
2019-02-23  1:40                                                             ` Linus Torvalds
2019-02-25  8:33                                                       ` Julien Thierry
2019-02-25 11:55                                                         ` Peter Zijlstra
2019-02-21 12:46                                             ` [PATCH] sched/x86: Save [ER]FLAGS on context switch Will Deacon
2019-02-21 22:06                                               ` Andy Lutomirski
2019-02-18  9:03                                 ` [PATCH v2] " Peter Zijlstra
2019-02-13 23:19                         ` [PATCH v3 3/4] uaccess: Check no rescheduling function is called in unsafe region Linus Torvalds
2019-01-15 13:58 ` [PATCH v3 4/4] arm64: uaccess: Implement user_access_region_active Julien Thierry
2019-01-25 14:27 ` [PATCH v3 0/4] uaccess: Add unsafe accessors for arm64 Catalin Marinas
2019-01-30 16:17 ` Julien Thierry

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAHk-=wj4Ws1s3iw+w62jcFdnarWhiVxs9zCBjoo7WysxRVZAgQ@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=bp@alien8.de \
    --cc=brgerst@gmail.com \
    --cc=catalin.marinas@arm.com \
    --cc=dvlasenk@redhat.com \
    --cc=hpa@zytor.com \
    --cc=james.morse@arm.com \
    --cc=jpoimboe@redhat.com \
    --cc=julien.thierry@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=luto@kernel.org \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=valentin.schneider@arm.com \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).