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* [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces
@ 2013-02-20 20:36 Matt Fleming
  2013-02-20 23:25 ` [tip:x86/urgent] " tip-bot for Matt Fleming
  2013-02-20 23:46 ` [PATCH] " Satoru Takeuchi
  0 siblings, 2 replies; 7+ messages in thread
From: Matt Fleming @ 2013-02-20 20:36 UTC (permalink / raw)
  To: H. Peter Anvin
  Cc: linux-kernel, linux-efi, Matt Fleming, Satoru Takeuchi, stable

From: Matt Fleming <matt.fleming@intel.com>

commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
its documentation and disable EFI runtime services to prevent the
bricking bug described in commit e0094244e41c ("samsung-laptop:
Disable on EFI hardware"). However, it's not possible to clear
EFI_RUNTIME_SERVICES from an early param function because
EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().

This resulted in "noefi" effectively becoming a no-op and no longer
providing users with a way to disable EFI, which is bad for those
users that have buggy machines.

Reported-by: Walt Nelson Jr <walt0924@gmail.com>
Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
---
 arch/x86/platform/efi/efi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 928bf83..e2cd38f 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -85,9 +85,10 @@ int efi_enabled(int facility)
 }
 EXPORT_SYMBOL(efi_enabled);
 
+static bool disable_runtime = false;
 static int __init setup_noefi(char *arg)
 {
-	clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
+	disable_runtime = true;
 	return 0;
 }
 early_param("noefi", setup_noefi);
@@ -734,7 +735,7 @@ void __init efi_init(void)
 	if (!efi_is_native())
 		pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
 	else {
-		if (efi_runtime_init())
+		if (disable_runtime || efi_runtime_init())
 			return;
 		set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
 	}
-- 
1.7.11.7


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [tip:x86/urgent] x86, efi: Make "noefi" really disable EFI runtime serivces
  2013-02-20 20:36 [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces Matt Fleming
@ 2013-02-20 23:25 ` tip-bot for Matt Fleming
  2013-02-21  0:16   ` Yinghai Lu
  2013-02-20 23:46 ` [PATCH] " Satoru Takeuchi
  1 sibling, 1 reply; 7+ messages in thread
From: tip-bot for Matt Fleming @ 2013-02-20 23:25 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: linux-kernel, hpa, mingo, stable, matt.fleming, takeuchi_satoru,
	tglx, hpa, walt0924

Commit-ID:  fb834c7acc5e140cf4f9e86da93a66de8c0514da
Gitweb:     http://git.kernel.org/tip/fb834c7acc5e140cf4f9e86da93a66de8c0514da
Author:     Matt Fleming <matt.fleming@intel.com>
AuthorDate: Wed, 20 Feb 2013 20:36:12 +0000
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Wed, 20 Feb 2013 13:18:36 -0800

x86, efi: Make "noefi" really disable EFI runtime serivces

commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
its documentation and disable EFI runtime services to prevent the
bricking bug described in commit e0094244e41c ("samsung-laptop:
Disable on EFI hardware"). However, it's not possible to clear
EFI_RUNTIME_SERVICES from an early param function because
EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().

This resulted in "noefi" effectively becoming a no-op and no longer
providing users with a way to disable EFI, which is bad for those
users that have buggy machines.

Reported-by: Walt Nelson Jr <walt0924@gmail.com>
Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
---
 arch/x86/platform/efi/efi.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 928bf83..e2cd38f 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -85,9 +85,10 @@ int efi_enabled(int facility)
 }
 EXPORT_SYMBOL(efi_enabled);
 
+static bool disable_runtime = false;
 static int __init setup_noefi(char *arg)
 {
-	clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
+	disable_runtime = true;
 	return 0;
 }
 early_param("noefi", setup_noefi);
@@ -734,7 +735,7 @@ void __init efi_init(void)
 	if (!efi_is_native())
 		pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
 	else {
-		if (efi_runtime_init())
+		if (disable_runtime || efi_runtime_init())
 			return;
 		set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
 	}

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces
  2013-02-20 20:36 [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces Matt Fleming
  2013-02-20 23:25 ` [tip:x86/urgent] " tip-bot for Matt Fleming
@ 2013-02-20 23:46 ` Satoru Takeuchi
  2013-02-20 23:50   ` H. Peter Anvin
  1 sibling, 1 reply; 7+ messages in thread
From: Satoru Takeuchi @ 2013-02-20 23:46 UTC (permalink / raw)
  To: Matt Fleming
  Cc: H. Peter Anvin, linux-kernel, linux-efi, Matt Fleming, stable

Hi Matt,

(2013/02/21 5:36), Matt Fleming wrote:
> From: Matt Fleming <matt.fleming@intel.com>
> 
> commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
> EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
> its documentation and disable EFI runtime services to prevent the
> bricking bug described in commit e0094244e41c ("samsung-laptop:
> Disable on EFI hardware"). However, it's not possible to clear
> EFI_RUNTIME_SERVICES from an early param function because
> EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().
> 
> This resulted in "noefi" effectively becoming a no-op and no longer
> providing users with a way to disable EFI, which is bad for those
> users that have buggy machines.

Sorry, my patch was imperfect. This patch looks good to me.

Reviewed-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>

Thanks,
Satoru

> 
> Reported-by: Walt Nelson Jr <walt0924@gmail.com>
> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
> Cc: H. Peter Anvin <hpa@linux.intel.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
> ---
>  arch/x86/platform/efi/efi.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 928bf83..e2cd38f 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -85,9 +85,10 @@ int efi_enabled(int facility)
>  }
>  EXPORT_SYMBOL(efi_enabled);
>  
> +static bool disable_runtime = false;
>  static int __init setup_noefi(char *arg)
>  {
> -	clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
> +	disable_runtime = true;
>  	return 0;
>  }
>  early_param("noefi", setup_noefi);
> @@ -734,7 +735,7 @@ void __init efi_init(void)
>  	if (!efi_is_native())
>  		pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
>  	else {
> -		if (efi_runtime_init())
> +		if (disable_runtime || efi_runtime_init())
>  			return;
>  		set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
>  	}
> 



^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces
  2013-02-20 23:46 ` [PATCH] " Satoru Takeuchi
@ 2013-02-20 23:50   ` H. Peter Anvin
  0 siblings, 0 replies; 7+ messages in thread
From: H. Peter Anvin @ 2013-02-20 23:50 UTC (permalink / raw)
  To: Satoru Takeuchi
  Cc: Matt Fleming, linux-kernel, linux-efi, Matt Fleming, stable

On 02/20/2013 03:46 PM, Satoru Takeuchi wrote:
> 
> Sorry, my patch was imperfect. This patch looks good to me.
> 

Perfection is something very rarely achieved.  That's why we work with
gradual improvements.

	-hpa


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [tip:x86/urgent] x86, efi: Make "noefi" really disable EFI runtime serivces
  2013-02-20 23:25 ` [tip:x86/urgent] " tip-bot for Matt Fleming
@ 2013-02-21  0:16   ` Yinghai Lu
  2013-02-21 10:33     ` Matt Fleming
  0 siblings, 1 reply; 7+ messages in thread
From: Yinghai Lu @ 2013-02-21  0:16 UTC (permalink / raw)
  To: mingo, hpa, linux-kernel, stable, matt.fleming, takeuchi_satoru,
	tglx, walt0924, hpa
  Cc: linux-tip-commits

On Wed, Feb 20, 2013 at 3:25 PM, tip-bot for Matt Fleming
<tipbot@zytor.com> wrote:
> Commit-ID:  fb834c7acc5e140cf4f9e86da93a66de8c0514da
> Gitweb:     http://git.kernel.org/tip/fb834c7acc5e140cf4f9e86da93a66de8c0514da
> Author:     Matt Fleming <matt.fleming@intel.com>
> AuthorDate: Wed, 20 Feb 2013 20:36:12 +0000
> Committer:  H. Peter Anvin <hpa@linux.intel.com>
> CommitDate: Wed, 20 Feb 2013 13:18:36 -0800
>
> x86, efi: Make "noefi" really disable EFI runtime serivces
>
> commit 1de63d60cd5b ("efi: Clear EFI_RUNTIME_SERVICES rather than
> EFI_BOOT by "noefi" boot parameter") attempted to make "noefi" true to
> its documentation and disable EFI runtime services to prevent the
> bricking bug described in commit e0094244e41c ("samsung-laptop:
> Disable on EFI hardware"). However, it's not possible to clear
> EFI_RUNTIME_SERVICES from an early param function because
> EFI_RUNTIME_SERVICES is set in efi_init() *after* parse_early_param().
>
> This resulted in "noefi" effectively becoming a no-op and no longer
> providing users with a way to disable EFI, which is bad for those
> users that have buggy machines.
>
> Reported-by: Walt Nelson Jr <walt0924@gmail.com>
> Cc: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
> Link: http://lkml.kernel.org/r/1361392572-25657-1-git-send-email-matt@console-pimps.org
> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
> ---
>  arch/x86/platform/efi/efi.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> index 928bf83..e2cd38f 100644
> --- a/arch/x86/platform/efi/efi.c
> +++ b/arch/x86/platform/efi/efi.c
> @@ -85,9 +85,10 @@ int efi_enabled(int facility)
>  }
>  EXPORT_SYMBOL(efi_enabled);
>
> +static bool disable_runtime = false;

__initdata please.

>  static int __init setup_noefi(char *arg)
>  {
> -       clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
> +       disable_runtime = true;
>         return 0;
>  }
>  early_param("noefi", setup_noefi);
> @@ -734,7 +735,7 @@ void __init efi_init(void)
>         if (!efi_is_native())
>                 pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
>         else {
> -               if (efi_runtime_init())
> +               if (disable_runtime || efi_runtime_init())
>                         return;
>                 set_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
>         }
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [tip:x86/urgent] x86, efi: Make "noefi" really disable EFI runtime serivces
  2013-02-21  0:16   ` Yinghai Lu
@ 2013-02-21 10:33     ` Matt Fleming
  2013-02-21 17:02       ` H. Peter Anvin
  0 siblings, 1 reply; 7+ messages in thread
From: Matt Fleming @ 2013-02-21 10:33 UTC (permalink / raw)
  To: Yinghai Lu
  Cc: mingo, hpa, linux-kernel, stable, takeuchi_satoru, tglx,
	walt0924, hpa, linux-tip-commits

On Wed, 2013-02-20 at 16:16 -0800, Yinghai Lu wrote:
> > diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
> > index 928bf83..e2cd38f 100644
> > --- a/arch/x86/platform/efi/efi.c
> > +++ b/arch/x86/platform/efi/efi.c
> > @@ -85,9 +85,10 @@ int efi_enabled(int facility)
> >  }
> >  EXPORT_SYMBOL(efi_enabled);
> >
> > +static bool disable_runtime = false;
> 
> __initdata please.

Sure. Peter, please drop this. I'll submit a v2.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [tip:x86/urgent] x86, efi: Make "noefi" really disable EFI runtime serivces
  2013-02-21 10:33     ` Matt Fleming
@ 2013-02-21 17:02       ` H. Peter Anvin
  0 siblings, 0 replies; 7+ messages in thread
From: H. Peter Anvin @ 2013-02-21 17:02 UTC (permalink / raw)
  To: Matt Fleming
  Cc: Yinghai Lu, mingo, hpa, linux-kernel, stable, takeuchi_satoru,
	tglx, walt0924, linux-tip-commits

On 02/21/2013 02:33 AM, Matt Fleming wrote:
> On Wed, 2013-02-20 at 16:16 -0800, Yinghai Lu wrote:
>>> diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
>>> index 928bf83..e2cd38f 100644
>>> --- a/arch/x86/platform/efi/efi.c
>>> +++ b/arch/x86/platform/efi/efi.c
>>> @@ -85,9 +85,10 @@ int efi_enabled(int facility)
>>>  }
>>>  EXPORT_SYMBOL(efi_enabled);
>>>
>>> +static bool disable_runtime = false;
>>
>> __initdata please.
> 
> Sure. Peter, please drop this. I'll submit a v2.
> 

Just do an incremental, please.

	-hpa


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2013-02-21 17:02 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-02-20 20:36 [PATCH] x86, efi: Make "noefi" really disable EFI runtime serivces Matt Fleming
2013-02-20 23:25 ` [tip:x86/urgent] " tip-bot for Matt Fleming
2013-02-21  0:16   ` Yinghai Lu
2013-02-21 10:33     ` Matt Fleming
2013-02-21 17:02       ` H. Peter Anvin
2013-02-20 23:46 ` [PATCH] " Satoru Takeuchi
2013-02-20 23:50   ` H. Peter Anvin

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