From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Rik van Riel <riel@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>, Borislav Petkov <bp@alien8.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Lutomirski <luto@kernel.org>,
dave.hansen@intel.linux.com, Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH RFC 1/3] fpu/x86: add make_fpregs_active(_newstate) helper functions
Date: Mon, 17 Oct 2016 16:04:17 -0700 [thread overview]
Message-ID: <20161017230416.GA18900@test-lenovo> (raw)
In-Reply-To: <CALCETrUKOF3PxUBXJ0xMwDdooCwv2R9Eso24kcb0mm1ZYYYdzg@mail.gmail.com>
On Mon, Oct 17, 2016 at 01:57:06PM -0700, Andy Lutomirski wrote:
> Dave and/or Yu-cheng: didn't one of you have some code to allow a user
> xstate buffer to be filled from the copy in kernel memory? If we did
> that, we could avoid this mess entirely.
In copy_fpstate_to_sigframe() (arch/x86/kernel/fpu/signal.c), the
assumption was we have lazy fpu:
if (fpregs_active() || we want an #NM exception)
copy_fpregs_to_sigframe();
else
copy kernel buffer to user buffer;
But this is not the true anymore. Or do you mean something else?
-- Yu-cheng
next prev parent reply other threads:[~2016-10-17 23:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-17 20:09 [PATCH RFC 0/3] x86/fpu: defer FPU state loading until return to userspace riel
2016-10-17 20:09 ` [PATCH RFC 1/3] fpu/x86: add make_fpregs_active(_newstate) helper functions riel
2016-10-17 20:57 ` Andy Lutomirski
2016-10-17 23:04 ` Yu-cheng Yu [this message]
2016-10-17 23:30 ` Andy Lutomirski
2016-10-17 23:45 ` Yu-cheng Yu
2016-10-18 1:23 ` Andy Lutomirski
2016-10-17 20:09 ` [PATCH RFC 2/3] x86/fpu: prepare misc FPU state handling code for lazy FPU loading riel
2016-10-17 20:09 ` [PATCH RFC 3/3] x86/fpu: defer FPU state load until return to userspace riel
2016-10-17 20:58 ` Andy Lutomirski
2016-10-18 0:06 ` Rik van Riel
2016-10-18 7:58 ` [PATCH RFC 0/3] x86/fpu: defer FPU state loading " Ingo Molnar
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=20161017230416.GA18900@test-lenovo \
--to=yu-cheng.yu@intel.com \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.linux.com \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=riel@redhat.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.