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From: "tip-bot for H. Peter Anvin" <hpa@linux.intel.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org,
	tglx@linutronix.de, rjw@sisk.pl, hpa@linux.intel.com
Subject: [tip:x86/urgent] x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID
Date: Mon, 1 Oct 2012 23:52:45 -0700	[thread overview]
Message-ID: <tip-1396adc3c2bdc556d4cdd1cf107aa0b6d59fbb1e@git.kernel.org> (raw)
In-Reply-To: <1348529239-17943-1-git-send-email-hpa@linux.intel.com>

Commit-ID:  1396adc3c2bdc556d4cdd1cf107aa0b6d59fbb1e
Gitweb:     http://git.kernel.org/tip/1396adc3c2bdc556d4cdd1cf107aa0b6d59fbb1e
Author:     H. Peter Anvin <hpa@linux.intel.com>
AuthorDate: Mon, 1 Oct 2012 14:34:42 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 2 Oct 2012 08:42:31 +0200

x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID

The patch:

    73201dbe x86, suspend: On wakeup always initialize cr4 and EFER

... was incorrectly committed in an intermediate (unfinished) form.

- We need to test CF, not ZF, for a bit test with btl.
- We don't actually need to compute the existence of EFLAGS.ID,
  since we set a flag at suspend time if CR4 should be restored.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Link: http://lkml.kernel.org/r/1348529239-17943-1-git-send-email-hpa@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/realmode/rm/wakeup_asm.S |   15 +++------------
 1 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/arch/x86/realmode/rm/wakeup_asm.S b/arch/x86/realmode/rm/wakeup_asm.S
index e56479e..9e7e147 100644
--- a/arch/x86/realmode/rm/wakeup_asm.S
+++ b/arch/x86/realmode/rm/wakeup_asm.S
@@ -74,18 +74,9 @@ ENTRY(wakeup_start)
 
 	lidtl	wakeup_idt
 
-	/* Clear the EFLAGS but remember if we have EFLAGS.ID */
-	movl $X86_EFLAGS_ID, %ecx
-	pushl %ecx
-	popfl
-	pushfl
-	popl %edi
+	/* Clear the EFLAGS */
 	pushl $0
 	popfl
-	pushfl
-	popl %edx
-	xorl %edx, %edi
-	andl %ecx, %edi		/* %edi is zero iff CPUID & %cr4 are missing */
 
 	/* Check header signature... */
 	movl	signature, %eax
@@ -120,12 +111,12 @@ ENTRY(wakeup_start)
 	movl	%eax, %cr3
 
 	btl	$WAKEUP_BEHAVIOR_RESTORE_CR4, %edi
-	jz	1f
+	jnc	1f
 	movl	pmode_cr4, %eax
 	movl	%eax, %cr4
 1:
 	btl	$WAKEUP_BEHAVIOR_RESTORE_EFER, %edi
-	jz	1f
+	jnc	1f
 	movl	pmode_efer, %eax
 	movl	pmode_efer + 4, %edx
 	movl	$MSR_EFER, %ecx

  parent reply	other threads:[~2012-10-02  6:53 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-21 19:43 [PATCH 00/11] x86: Supervisor Mode Access Prevention H. Peter Anvin
2012-09-21 19:43 ` [PATCH 01/11] x86, cpufeature: Add feature bit for SMAP H. Peter Anvin
2012-09-21 19:43 ` [PATCH 02/11] x86-32, mm: The WP test should be done on a kernel page H. Peter Anvin
2012-09-21 19:58   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 03/11] x86, smap: Add CR4 bit for SMAP H. Peter Anvin
2012-09-21 19:59   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 04/11] x86, alternative: Use .pushsection/.popsection H. Peter Anvin
2012-09-21 20:00   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 05/11] x86, alternative: Add header guards to <asm/alternative-asm.h> H. Peter Anvin
2012-09-21 20:01   ` [tip:x86/smap] x86, alternative: Add header guards to <asm/ alternative-asm.h> tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 06/11] x86, smap: Add a header file with macros for STAC/CLAC H. Peter Anvin
2012-09-21 20:02   ` [tip:x86/smap] x86, smap: Add a header file with macros for STAC/ CLAC tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 07/11] x86, uaccess: Merge prototypes for clear_user/__clear_user H. Peter Anvin
2012-09-21 20:03   ` [tip:x86/smap] x86, uaccess: Merge prototypes for clear_user/ __clear_user tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 08/11] x86, smap: Add STAC and CLAC instructions to control user space access H. Peter Anvin
2012-09-21 20:04   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-22  0:16   ` [tip:x86/smap] x86-32, smap: Add STAC/ CLAC instructions to 32-bit kernel entry tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 09/11] x86, smap: Turn on Supervisor Mode Access Prevention H. Peter Anvin
2012-09-21 20:05   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 10/11] x86, smap: A page fault due to SMAP is an oops H. Peter Anvin
2012-09-21 20:06   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:43 ` [PATCH 11/11] x86, smap: Reduce the SMAP overhead for signal handling H. Peter Anvin
2012-09-21 20:07   ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-09-21 19:54 ` [PATCH 00/11] x86: Supervisor Mode Access Prevention Linus Torvalds
2012-09-21 19:57   ` H. Peter Anvin
2012-09-21 20:08   ` Ingo Molnar
2012-09-21 21:03     ` H. Peter Anvin
2012-09-21 21:09       ` Linus Torvalds
2012-09-21 21:12         ` H. Peter Anvin
2012-09-21 22:07 ` Eric W. Biederman
2012-09-21 22:12   ` H. Peter Anvin
2012-09-22  0:41     ` Eric W. Biederman
2012-09-24 23:27       ` [RFC PATCH] x86-32: Start out eflags and cr4 clean H. Peter Anvin
2012-09-25 13:27         ` Konrad Rzeszutek Wilk
2012-09-25 13:48         ` Ian Campbell
2012-09-26 11:29           ` Konrad Rzeszutek Wilk
2012-09-27  6:11         ` [tip:x86/smap] " tip-bot for H. Peter Anvin
2012-11-24  3:49           ` Yuhong Bao
2012-11-24  5:06             ` H. Peter Anvin
2012-09-27  6:11         ` [tip:x86/smap] x86, suspend: On wakeup always initialize cr4 and EFER tip-bot for H. Peter Anvin
2012-10-01 22:04         ` [tip:x86/urgent] x86, suspend: Correct the restore of CR4, EFER; skip computing EFLAGS.ID tip-bot for H. Peter Anvin
2012-10-02  6:52         ` tip-bot for H. Peter Anvin [this message]
2012-10-10 19:59         ` [RFC PATCH] x86-32: Start out eflags and cr4 clean Andres Salomon
2013-01-19  0:40           ` Andres Salomon
2013-01-19  0:42             ` H. Peter Anvin
2013-01-19  1:05               ` [Techteam] " Mitch Bradley
2013-01-19  2:35                 ` H. Peter Anvin
2013-01-19  7:44                   ` Mitch Bradley
2013-01-19 12:34                   ` Daniel Drake
2013-01-19 19:15                   ` [tip:x86/urgent] x86-32: Start out cr0 clean, disable paging before modifying cr3/4 tip-bot for H. Peter Anvin
2012-09-21 22:08 ` [PATCH 00/11] x86: Supervisor Mode Access Prevention Dave Jones
2012-09-21 22:10   ` H. Peter Anvin
2012-09-22 11:32     ` Ingo Molnar
2012-09-24 20:31       ` H. Peter Anvin
2012-09-24 20:43         ` Kees Cook
2012-09-24 20:51           ` H. Peter Anvin

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