linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Kyle Huey <me@kylehuey.com>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Robert O'Callahan" <robert@ocallahan.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
	<x86@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>,
	Anna Schumaker <Anna.Schumaker@netapp.com>,
	David Howells <dhowells@redhat.com>,
	"Dmitry V. Levin" <ldv@altlinux.org>,
	Eric B Munson <emunson@akamai.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jiri Slaby <jslaby@suse.cz>,
	Andrey Ryabinin <aryabinin@virtuozzo.com>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Borislav Petkov <bp@alien8.de>,
	Dmitry Vyukov <dvyukov@google.com>,
	"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" 
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/3] syscalls,x86 Expose arch_prctl on x86-32.
Date: Wed, 14 Sep 2016 14:56:58 -0700	[thread overview]
Message-ID: <CAP045ArGrKbA9U-VPEwMcQVXn22Z5VyKDMYiXK2YzZZi2xhFeA@mail.gmail.com> (raw)
In-Reply-To: <57D9C54B.3010105@linux.intel.com>

On Wed, Sep 14, 2016 at 2:46 PM, Dave Hansen
<dave.hansen@linux.intel.com> wrote:
> On 09/14/2016 02:35 PM, Kyle Huey wrote:
>> It's not quite a plain move.  To leave the existing arch_prctls only
>> accessible to 64 bit callers, I added the is_32 bit and the four early
>> returns for each existing ARCH_BLAH.  These cases are now
>> conditionally compiled out in a 32 bit kernel, so we only have to
>> handle the 32 bit process on a 64 bit kernel case at runtime.
>
> I think it would make a lot of sense to do the move and the modification
> in two patches.

Ok.

> Oh, and arch_prctl() really *is* 64-bit only.  I didn't realize that.
> That would have been nice to call out in the changelog, too.  It's
> totally non-obvious.

Ok.

> You're going to owe some manpage updates after this too, I guess.  It
> says: "arch_prctl() is supported only on Linux/x86-64 for 64-bit
> programs currently."

Indeed. There's a patch at the end of the series (sent to LKML, but
you're not directly CCd on it) with a suggested manpage patch.

> FWIW, I don't think it would be horrible to leave the existing
> do_arch_prctl() code in process_64.h and call it
> do_64_bit_only_something_arch_prctl(), and only call in to it from the
> generic do_arch_prctl().  You really have one reason for all the "if
> (is_32)"'s and it would be nice to document why in one single place.

Yeah, that seems like a good idea.

- Kyle

  reply	other threads:[~2016-09-14 21:58 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1473886902-17902-1-git-send-email-khuey@kylehuey.com>
2016-09-14 21:01 ` [PATCH v2 1/3] syscalls,x86 Expose arch_prctl on x86-32 Kyle Huey
2016-09-14 21:29   ` Dave Hansen
2016-09-14 21:35     ` Kyle Huey
2016-09-14 21:46       ` Dave Hansen
2016-09-14 21:56         ` Kyle Huey [this message]
2016-09-14 22:23   ` kbuild test robot
2016-09-15  0:01   ` kbuild test robot
2016-09-15  0:01   ` kbuild test robot
2016-09-15  1:14   ` Andy Lutomirski
2016-09-14 21:01 ` [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Kyle Huey
2016-09-14 21:35   ` Dave Hansen
2016-09-14 22:03     ` Kyle Huey
2016-09-15  1:17       ` Andy Lutomirski
2016-09-15  2:20         ` Kyle Huey
2016-09-15 20:38         ` H. Peter Anvin
2016-09-15 23:18           ` Andy Lutomirski
2016-09-15 10:07     ` David Vrabel
2016-09-15 10:05   ` [Xen-devel] " David Vrabel
2016-09-15 10:25     ` Jan Beulich
2016-09-15 19:11       ` Kyle Huey
2016-09-15 19:37         ` Andy Lutomirski
2016-09-15 23:36           ` Kyle Huey
2016-09-15 19:41         ` Boris Ostrovsky
2016-09-14 21:01 ` [PATCH v2 3/3] x86,arch_prctl Add ARCH_[GET|SET]_CPUID for controlling the CPUID instruction Kyle Huey
2016-09-15  1:29   ` Andy Lutomirski
2016-09-15  1:47     ` Kyle Huey
2016-09-15  1:54       ` Andy Lutomirski
2016-09-15  2:19         ` Kyle Huey

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=CAP045ArGrKbA9U-VPEwMcQVXn22Z5VyKDMYiXK2YzZZi2xhFeA@mail.gmail.com \
    --to=me@kylehuey.com \
    --cc=Anna.Schumaker@netapp.com \
    --cc=aryabinin@virtuozzo.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=dhowells@redhat.com \
    --cc=dvyukov@google.com \
    --cc=emunson@akamai.com \
    --cc=hpa@zytor.com \
    --cc=jslaby@suse.cz \
    --cc=ldv@altlinux.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=mst@redhat.com \
    --cc=paul.gortmaker@windriver.com \
    --cc=peterz@infradead.org \
    --cc=robert@ocallahan.org \
    --cc=tglx@linutronix.de \
    --cc=viro@zeniv.linux.org.uk \
    --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).