[GIT PULL] x86, microcode fixes for 3.2

[GIT PULL] x86, microcode fixes for 3.2

[Borislav Petkov]

Hi Ingo,

please pull the following two fixes for the microcode machinery.

Thanks.

The following changes since commit caca6a03d365883564885f2c1da3e88dcf65d139:

  Linux 3.2-rc3 (2011-11-23 20:20:28 -0800)

are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git ucode

Borislav Petkov (1):
      x86, microcode, AMD: Restrict microcode reporting

Srivatsa S. Bhat (1):
      x86, microcode: Fix the failure path of microcode update driver init code

 arch/x86/kernel/cpu/amd.c        |    3 ++-
 arch/x86/kernel/microcode_core.c |   19 +++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)


-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

Re: [GIT PULL] x86, microcode fixes for 3.2

[Borislav Petkov]

On Mon, Nov 28, 2011 at 09:43:11PM +0100, Borislav Petkov wrote:
> Hi Ingo,
> 
> please pull the following two fixes for the microcode machinery.
> 
> Thanks.
> 
> The following changes since commit caca6a03d365883564885f2c1da3e88dcf65d139:
> 
>   Linux 3.2-rc3 (2011-11-23 20:20:28 -0800)
> 
> are available in the git repository at:
>   git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git ucode
> 
> Borislav Petkov (1):
>       x86, microcode, AMD: Restrict microcode reporting
> 
> Srivatsa S. Bhat (1):
>       x86, microcode: Fix the failure path of microcode update driver init code

Since you haven't pulled yet, I've updated this one with the better
version below, branch above has been updated too:

--
From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Date: Mon, 7 Nov 2011 18:05:32 +0530
Subject: [PATCH] x86, microcode: Fix the failure path of microcode update
 driver init code

The microcode update driver's initialization code does not handle
failures correctly. This patch fixes this issue.

Signed-off-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20111107123530.12164.31227.stgit@srivatsabhat.in.ibm.com
Link: http://lkml.kernel.org/r/4ED8E2270200007800065120@nat28.tlf.novell.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/kernel/microcode_core.c |   28 +++++++++++++++++++---------
 1 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index f2d2a66..9d46f5e 100644
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -256,7 +256,7 @@ static int __init microcode_dev_init(void)
 	return 0;
 }
 
-static void microcode_dev_exit(void)
+static void __exit microcode_dev_exit(void)
 {
 	misc_deregister(&microcode_dev);
 }
@@ -519,10 +519,8 @@ static int __init microcode_init(void)
 
 	microcode_pdev = platform_device_register_simple("microcode", -1,
 							 NULL, 0);
-	if (IS_ERR(microcode_pdev)) {
-		microcode_dev_exit();
+	if (IS_ERR(microcode_pdev))
 		return PTR_ERR(microcode_pdev);
-	}
 
 	get_online_cpus();
 	mutex_lock(&microcode_mutex);
@@ -532,14 +530,12 @@ static int __init microcode_init(void)
 	mutex_unlock(&microcode_mutex);
 	put_online_cpus();
 
-	if (error) {
-		platform_device_unregister(microcode_pdev);
-		return error;
-	}
+	if (error)
+		goto out_pdev;
 
 	error = microcode_dev_init();
 	if (error)
-		return error;
+		goto out_sysdev_driver;
 
 	register_syscore_ops(&mc_syscore_ops);
 	register_hotcpu_notifier(&mc_cpu_notifier);
@@ -548,6 +544,20 @@ static int __init microcode_init(void)
 		" <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
 
 	return 0;
+
+out_sysdev_driver:
+	get_online_cpus();
+	mutex_lock(&microcode_mutex);
+
+	sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
+
+	mutex_unlock(&microcode_mutex);
+	put_online_cpus();
+
+out_pdev:
+	platform_device_unregister(microcode_pdev);
+	return error;
+
 }
 module_init(microcode_init);
 
-- 
1.7.8.rc0

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

Re: [GIT PULL] x86, microcode fixes for 3.2

[Ingo Molnar]

* Borislav Petkov <bp@amd64.org> wrote:

> On Mon, Nov 28, 2011 at 09:43:11PM +0100, Borislav Petkov wrote:
> > Hi Ingo,
> > 
> > please pull the following two fixes for the microcode machinery.
> > 
> > Thanks.
> > 
> > The following changes since commit caca6a03d365883564885f2c1da3e88dcf65d139:
> > 
> >   Linux 3.2-rc3 (2011-11-23 20:20:28 -0800)
> > 
> > are available in the git repository at:
> >   git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git ucode
> > 
> > Borislav Petkov (1):
> >       x86, microcode, AMD: Restrict microcode reporting
> > 
> > Srivatsa S. Bhat (1):
> >       x86, microcode: Fix the failure path of microcode update driver init code
> 
> Since you haven't pulled yet, I've updated this one with the better
> version below, branch above has been updated too:
> 
> --
> From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
> Date: Mon, 7 Nov 2011 18:05:32 +0530
> Subject: [PATCH] x86, microcode: Fix the failure path of microcode update
>  driver init code
> 
> The microcode update driver's initialization code does not handle
> failures correctly. This patch fixes this issue.
> 
> Signed-off-by: Jan Beulich <JBeulich@suse.com>
> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
> Link: http://lkml.kernel.org/r/20111107123530.12164.31227.stgit@srivatsabhat.in.ibm.com
> Link: http://lkml.kernel.org/r/4ED8E2270200007800065120@nat28.tlf.novell.com
> Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
> ---

Mind respinning this once more against latest -git? There's a 
new conflict due to:

  8e8da023f5af: x86: Fix boot failures on older AMD CPU's

Thanks,

	Ingo

Re: [GIT PULL] x86, microcode fixes for 3.2

[Borislav Petkov]

On Mon, Dec 05, 2011 at 10:26:12AM +0100, Ingo Molnar wrote:
> Mind respinning this once more against latest -git? There's a 
> new conflict due to:
> 
>   8e8da023f5af: x86: Fix boot failures on older AMD CPU's

Branch is updated, it also contains the following patch:

--
From: Borislav Petkov <borislav.petkov@amd.com>
Date: Mon, 5 Dec 2011 14:28:37 +0100
Subject: [PATCH] x86: Document rdmsr_safe restrictions

Recently, I got bitten by using rdmsr_safe too early in the boot
process. Document its shortcomings for future reference.

Link: http://lkml.kernel.org/r/4ED5B70F.606@lwfinger.net
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
---
 arch/x86/include/asm/msr.h |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 084ef95..95203d4 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -169,7 +169,14 @@ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
 	return native_write_msr_safe(msr, low, high);
 }
 
-/* rdmsr with exception handling */
+/*
+ * rdmsr with exception handling.
+ *
+ * Please note that the exception handling works only after we've
+ * switched to the "smart" #GP handler in trap_init() which knows about
+ * exception tables - using this macro earlier than that causes machine
+ * hangs on boxes which do not implement the @msr in the first argument.
+ */
 #define rdmsr_safe(msr, p1, p2)					\
 ({								\
 	int __err;						\
-- 
1.7.8.rc0

Thanks.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

Re: [GIT PULL] x86, microcode fixes for 3.2

[H. Peter Anvin]

On 12/05/2011 07:10 AM, Borislav Petkov wrote:
> 
> diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
> index 084ef95..95203d4 100644
> --- a/arch/x86/include/asm/msr.h
> +++ b/arch/x86/include/asm/msr.h
> @@ -169,7 +169,14 @@ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high)
>  	return native_write_msr_safe(msr, low, high);
>  }
>  
> -/* rdmsr with exception handling */
> +/*
> + * rdmsr with exception handling.
> + *
> + * Please note that the exception handling works only after we've
> + * switched to the "smart" #GP handler in trap_init() which knows about
> + * exception tables - using this macro earlier than that causes machine
> + * hangs on boxes which do not implement the @msr in the first argument.
> + */
>  #define rdmsr_safe(msr, p1, p2)					\
>  ({								\
>  	int __err;						\

I keep wondering if we couldn't have the early-static trap handlers be
aware of exception tables, too; they wouldn't have to worry about
modules and so it would be reasonably easy.

	-hpa

Re: [GIT PULL] x86, microcode fixes for 3.2

[Borislav Petkov]

On Sun, Mar 25, 2012 at 12:27:23PM -0700, H. Peter Anvin wrote:
> I keep wondering if we couldn't have the early-static trap handlers be
> aware of exception tables, too; they wouldn't have to worry about
> modules and so it would be reasonably easy.

Well, we talked about this recently and then we decided we needed the
extable-sorting-at-build-time patches before we make those static trap
handlers aware of extables. What happened to those patches, btw? See
thread at http://marc.info/?l=linux-kernel&m=132196692827070

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

Re: [GIT PULL] x86, microcode fixes for 3.2

[H. Peter Anvin]

On 03/26/2012 01:48 AM, Borislav Petkov wrote:
> On Sun, Mar 25, 2012 at 12:27:23PM -0700, H. Peter Anvin wrote:
>> I keep wondering if we couldn't have the early-static trap handlers be
>> aware of exception tables, too; they wouldn't have to worry about
>> modules and so it would be reasonably easy.
> 
> Well, we talked about this recently and then we decided we needed the
> extable-sorting-at-build-time patches before we make those static trap
> handlers aware of extables. What happened to those patches, btw? See
> thread at http://marc.info/?l=linux-kernel&m=132196692827070
> 

Hm... I hope that didn't stall out because of me... the amount of
overload I have been under lately is a bit scary.

I was going to dredge out the perfect hash stuff that I had, but the
sorting stuff could be done without that.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

Re: [GIT PULL] x86, microcode fixes for 3.2

[Borislav Petkov]

On Mon, Mar 26, 2012 at 07:52:45AM -0700, H. Peter Anvin wrote:
> On 03/26/2012 01:48 AM, Borislav Petkov wrote:
> > On Sun, Mar 25, 2012 at 12:27:23PM -0700, H. Peter Anvin wrote:
> >> I keep wondering if we couldn't have the early-static trap handlers be
> >> aware of exception tables, too; they wouldn't have to worry about
> >> modules and so it would be reasonably easy.
> > 
> > Well, we talked about this recently and then we decided we needed the
> > extable-sorting-at-build-time patches before we make those static trap
> > handlers aware of extables. What happened to those patches, btw? See
> > thread at http://marc.info/?l=linux-kernel&m=132196692827070
> > 
> 
> Hm... I hope that didn't stall out because of me... the amount of
> overload I have been under lately is a bit scary.
> 
> I was going to dredge out the perfect hash stuff that I had, but the
> sorting stuff could be done without that.

Ok, let me scratch up something in the coming days.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
GM: Alberto Bozzo
Reg: Dornach, Landkreis Muenchen
HRB Nr. 43632 WEEE Registernr: 129 19551

Re: [GIT PULL] x86, microcode fixes for 3.2

[H. Peter Anvin]

Here is a version of the automatic hash generator written in Perl:

http://www.zytor.com/~hpa/phash/

There is another one based on code written by Bob Jenkins, in C, and
based on a different algorithm included with libucd:

git://git.kernel.org/pub/scm/libs/libucd/libucd.git

It is *much* slower to converge, but probably generates at least
marginally faster lookup code.

	-hpa