From: Linus Torvalds <torvalds@linux-foundation.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org
Cc: Raphael Prevost <raphael@buro.asia>,
Suresh Siddha <suresh.b.siddha@intel.com>,
Peter Anvin <hpa@zytor.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH 4/5] i387: move TS_USEDFPU clearing out of __save_init_fpu and into callers
Date: Wed, 22 Feb 2012 12:58:11 -0800 (PST) [thread overview]
Message-ID: <alpine.LFD.2.02.1202221257410.20522@i5.linux-foundation.org> (raw)
In-Reply-To: <alpine.LFD.2.02.1202221256450.20522@i5.linux-foundation.org>
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 16 Feb 2012 12:22:48 -0800
[ Upstream commit b6c66418dcad0fcf83cd1d0a39482db37bf4fc41 ]
Touching TS_USEDFPU without touching CR0.TS is confusing, so don't do
it. By moving it into the callers, we always do the TS_USEDFPU next to
the CR0.TS accesses in the source code, and it's much easier to see how
the two go hand in hand.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@kernel.org # Helps backporting
---
arch/x86/include/asm/i387.h | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h
index 6e87fa43c357..55fb3aa84b0d 100644
--- a/arch/x86/include/asm/i387.h
+++ b/arch/x86/include/asm/i387.h
@@ -259,7 +259,6 @@ static inline void fpu_save_init(struct fpu *fpu)
static inline void __save_init_fpu(struct task_struct *tsk)
{
fpu_save_init(&tsk->thread.fpu);
- task_thread_info(tsk)->status &= ~TS_USEDFPU;
}
static inline int fpu_fxrstor_checking(struct fpu *fpu)
@@ -290,6 +289,7 @@ static inline void __unlazy_fpu(struct task_struct *tsk)
{
if (task_thread_info(tsk)->status & TS_USEDFPU) {
__save_init_fpu(tsk);
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
stts();
} else
tsk->fpu_counter = 0;
@@ -356,9 +356,11 @@ static inline void kernel_fpu_begin(void)
WARN_ON_ONCE(!irq_fpu_usable());
preempt_disable();
- if (me->status & TS_USEDFPU)
+ if (me->status & TS_USEDFPU) {
__save_init_fpu(me->task);
- else
+ me->status &= ~TS_USEDFPU;
+ /* We do 'stts()' in kernel_fpu_end() */
+ } else
clts();
}
@@ -449,6 +451,7 @@ static inline void save_init_fpu(struct task_struct *tsk)
WARN_ON_ONCE(!(task_thread_info(tsk)->status & TS_USEDFPU));
preempt_disable();
__save_init_fpu(tsk);
+ task_thread_info(tsk)->status &= ~TS_USEDFPU;
stts();
preempt_enable();
}
--
1.7.9.188.g12766.dirty
next prev parent reply other threads:[~2012-02-22 20:58 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-22 20:54 [PATCH 0/5] i387: stable kernel backport Linus Torvalds
2012-02-22 20:56 ` [PATCH 1/5] i387: math_state_restore() isn't called from asm Linus Torvalds
2012-02-22 20:56 ` [PATCH 2/5] i387: make irq_fpu_usable() tests more robust Linus Torvalds
2012-02-22 20:57 ` [PATCH 3/5] i387: fix x86-64 preemption-unsafe user stack save/restore Linus Torvalds
2012-02-22 20:58 ` Linus Torvalds [this message]
2012-02-22 20:59 ` [PATCH 5/5] i387: move TS_USEDFPU flag from thread_info to task_struct Linus Torvalds
2012-02-22 21:02 ` [PATCH 0/5] i387: stable kernel backport H. Peter Anvin
2012-02-22 21:19 ` Greg Kroah-Hartman
2012-02-22 21:29 ` Linus Torvalds
2012-02-22 21:30 ` Linus Torvalds
2012-02-22 21:32 ` Greg Kroah-Hartman
2012-02-23 20:09 ` Greg Kroah-Hartman
2012-02-23 20:29 ` H. Peter Anvin
2012-02-23 20:48 ` Greg Kroah-Hartman
2012-02-23 20:51 ` H. Peter Anvin
2012-02-23 21:10 ` Greg Kroah-Hartman
2012-02-23 21:52 ` Willy Tarreau
2012-02-23 22:11 ` Linus Torvalds
2012-02-23 22:27 ` Willy Tarreau
2012-02-23 22:38 ` Linus Torvalds
2012-02-23 22:48 ` H. Peter Anvin
2012-02-23 22:52 ` Willy Tarreau
2012-02-23 22:55 ` H. Peter Anvin
2012-02-23 23:04 ` Willy Tarreau
2012-02-23 22:49 ` Willy Tarreau
2012-02-23 22:59 ` Greg Kroah-Hartman
2012-02-23 23:05 ` H. Peter Anvin
2012-02-23 23:16 ` Greg Kroah-Hartman
2012-02-23 23:18 ` H. Peter Anvin
2012-02-23 23:19 ` Suresh Siddha
2012-02-23 23:54 ` Greg Kroah-Hartman
2012-02-23 23:59 ` H. Peter Anvin
2012-02-24 0:47 ` H. Peter Anvin
2012-02-22 22:34 ` H. Peter Anvin
2012-02-22 22:45 ` H. Peter Anvin
2012-02-22 23:15 ` Linus Torvalds
2012-02-22 23:31 ` Linus Torvalds
2012-02-23 0:14 ` H. Peter Anvin
2012-02-23 0:25 ` Linus Torvalds
2012-02-23 0:37 ` Greg Kroah-Hartman
2012-02-23 1:47 ` raphael
2012-02-23 2:55 ` Linus Torvalds
2012-02-23 2:41 ` raphael
2012-02-23 3:37 ` Linus Torvalds
2012-02-23 18:15 ` Greg Kroah-Hartman
2012-02-23 19:36 ` Greg Kroah-Hartman
2012-02-23 19:41 ` Linus Torvalds
2012-02-23 19:50 ` Greg Kroah-Hartman
2012-02-23 19:55 ` Greg Kroah-Hartman
2012-02-23 20:02 ` Greg Kroah-Hartman
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=alpine.LFD.2.02.1202221257410.20522@i5.linux-foundation.org \
--to=torvalds@linux-foundation.org \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=raphael@buro.asia \
--cc=stable@vger.kernel.org \
--cc=suresh.b.siddha@intel.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).