From: Ingo Molnar <mingo@kernel.org>
To: Dan Williams <dan.j.williams@intel.com>
Cc: tglx@linutronix.de, linux-arch@vger.kernel.org,
kernel-hardening@lists.openwall.com, gregkh@linuxfoundation.org,
x86@kernel.org, Ingo Molnar <mingo@redhat.com>,
Andy Lutomirski <luto@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
torvalds@linux-foundation.org, alan@linux.intel.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 07/12] x86: remove the syscall_64 fast-path
Date: Sun, 28 Jan 2018 10:29:14 +0100 [thread overview]
Message-ID: <20180128092914.dabnzq7arv4bebhn@gmail.com> (raw)
In-Reply-To: <151703975137.26578.11230688940391207602.stgit@dwillia2-desk3.amr.corp.intel.com>
* Dan Williams <dan.j.williams@intel.com> wrote:
> Quoting Linus:
>
> "Honestly, I'd rather get rid of the fast-path entirely. Compared to
> all the PTI mess, it's not even noticeable.
>
> And if we ever get CPU's that have this all fixed, we can re-visit
> introducing the fastpath. But this is all very messy and it doesn't
> seem worth it right now.
>
> If we get rid of the fastpath, we can lay out the slow path slightly
> better, and get rid of some of those jump-overs. And we'd get rid of
> the ptregs hooks entirely.
>
> So we can try to make the "slow" path better while at it, but I
> really don't think it matters much now in the post-PTI era. Sadly."
Please fix the title to have the proper prefix and to reference the function that
is actually modified by the patch, i.e. something like:
s/ x86: remove the syscall_64 fast-path
/ x86/entry/64: Remove the entry_SYSCALL_64() fast-path
With the title fixed:
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Thanks,
Ingo
next prev parent reply other threads:[~2018-01-28 9:29 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-27 7:55 [PATCH v5 00/12] spectre variant1 mitigations for tip/x86/pti Dan Williams
2018-01-27 7:55 ` Dan Williams
2018-01-27 7:55 ` [PATCH v5 01/12] Documentation: document array_idx Dan Williams
2018-01-27 7:55 ` [PATCH v5 02/12] array_idx: sanitize speculative array de-references Dan Williams
2018-01-27 7:55 ` Dan Williams
2018-01-28 8:55 ` Ingo Molnar
2018-01-28 11:36 ` Thomas Gleixner
2018-01-28 11:36 ` Thomas Gleixner
2018-01-28 16:28 ` Dan Williams
2018-01-28 18:33 ` Ingo Molnar
2018-01-29 16:45 ` Dan Williams
2018-01-29 16:45 ` Dan Williams
2018-01-28 18:36 ` Thomas Gleixner
2018-01-28 18:36 ` Thomas Gleixner
2018-01-30 6:29 ` Dan Williams
2018-01-30 6:29 ` Dan Williams
2018-01-30 19:38 ` Linus Torvalds
2018-01-30 20:13 ` Dan Williams
2018-01-30 20:27 ` Van De Ven, Arjan
2018-01-31 8:03 ` Ingo Molnar
2018-01-31 14:13 ` Van De Ven, Arjan
2018-01-31 14:21 ` Greg KH
2018-01-27 7:55 ` [PATCH v5 03/12] x86: implement array_idx_mask Dan Williams
2018-01-28 9:02 ` Ingo Molnar
2018-01-27 7:55 ` [PATCH v5 04/12] x86: introduce __uaccess_begin_nospec and ifence Dan Williams
2018-01-28 9:06 ` Ingo Molnar
2018-01-28 9:14 ` Ingo Molnar
2018-01-29 20:41 ` Dan Williams
2018-01-29 20:41 ` Dan Williams
2018-01-30 6:56 ` Ingo Molnar
2018-01-27 7:55 ` [PATCH v5 05/12] x86, __get_user: use __uaccess_begin_nospec Dan Williams
2018-01-28 9:19 ` Ingo Molnar
2018-01-28 9:19 ` Ingo Molnar
2018-01-27 7:55 ` [PATCH v5 06/12] x86, get_user: use pointer masking to limit speculation Dan Williams
2018-01-27 7:55 ` Dan Williams
2018-01-28 9:25 ` Ingo Molnar
2018-01-28 9:25 ` Ingo Molnar
2018-01-27 7:55 ` [PATCH v5 07/12] x86: remove the syscall_64 fast-path Dan Williams
2018-01-28 9:29 ` Ingo Molnar [this message]
2018-01-28 9:29 ` Ingo Molnar
2018-01-28 15:22 ` Andy Lutomirski
2018-01-28 15:22 ` Andy Lutomirski
2018-01-27 7:55 ` [PATCH v5 08/12] x86: sanitize sycall table de-references under speculation Dan Williams
2018-01-28 9:36 ` Ingo Molnar
2018-01-27 7:56 ` [PATCH v5 09/12] vfs, fdtable: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-27 7:56 ` [PATCH v5 10/12] kvm, x86: update spectre-v1 mitigation Dan Williams
[not found] ` <151703971300.26578.1185595719337719486.stgit-p8uTFz9XbKj2zm6wflaqv1nYeNYlB/vhral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2018-01-27 7:56 ` [PATCH v5 11/12] nl80211: sanitize array index in parse_txq_params Dan Williams
2018-01-27 7:56 ` Dan Williams
2018-01-27 7:56 ` [PATCH v5 12/12] x86/spectre: report get_user mitigation for spectre_v1 Dan Williams
2018-01-28 9:50 ` Ingo Molnar
2018-01-29 22:05 ` Dan Williams
2018-01-31 8:07 ` Ingo Molnar
2018-02-01 20:23 ` Dan Williams
2018-02-01 20:23 ` Dan Williams
2018-01-27 18:52 ` [PATCH v5 00/12] spectre variant1 mitigations for tip/x86/pti Linus Torvalds
2018-01-27 18:52 ` Linus Torvalds
2018-01-27 19:26 ` Dan Williams
2018-01-27 19:26 ` Dan Williams
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=20180128092914.dabnzq7arv4bebhn@gmail.com \
--to=mingo@kernel.org \
--cc=alan@linux.intel.com \
--cc=dan.j.williams@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/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).