Patchwork [3.5.y.z,extended,stable] Patch "efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by" has been added to staging queue

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Submitter Herton Ronaldo Krzesinski
Date Feb. 19, 2013, 6:15 p.m.
Message ID <1361297726-8170-1-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/221758/
State New
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Comments

Herton Ronaldo Krzesinski - Feb. 19, 2013, 6:15 p.m.
This is a note to let you know that I have just added a patch titled

    efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

From 6bdc907045202b73449c313f36b8d3eebe9bdea6 Mon Sep 17 00:00:00 2001
From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Date: Thu, 14 Feb 2013 09:12:52 +0900
Subject: [PATCH] efi: Clear EFI_RUNTIME_SERVICES rather than EFI_BOOT by
 "noefi" boot parameter

commit 1de63d60cd5b0d33a812efa455d5933bf1564a51 upstream.

There was a serious problem in samsung-laptop that its platform driver is
designed to run under BIOS and running under EFI can cause the machine to
become bricked or can cause Machine Check Exceptions.

    Discussion about this problem:
    https://bugs.launchpad.net/ubuntu-cdimage/+bug/1040557
    https://bugzilla.kernel.org/show_bug.cgi?id=47121

    The patches to fix this problem:
    efi: Make 'efi_enabled' a function to query EFI facilities
    83e68189745ad931c2afd45d8ee3303929233e7f

    samsung-laptop: Disable on EFI hardware
    e0094244e41c4d0c7ad69920681972fc45d8ce34

Unfortunately this problem comes back again if users specify "noefi" option.
This parameter clears EFI_BOOT and that driver continues to run even if running
under EFI. Refer to the document, this parameter should clear
EFI_RUNTIME_SERVICES instead.

Documentation/kernel-parameters.txt:
--
1.7.9.5

Patch

===============================================================================
...
	noefi		[X86] Disable EFI runtime services support.
...
===============================================================================

Documentation/x86/x86_64/uefi.txt:
===============================================================================
...
- If some or all EFI runtime services don't work, you can try following
  kernel command line parameters to turn off some or all EFI runtime
  services.
	noefi		turn off all EFI runtime services
...
===============================================================================

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Link: http://lkml.kernel.org/r/511C2C04.2070108@jp.fujitsu.com
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 arch/x86/platform/efi/efi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 6fcd4ad..3705bb0 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -86,7 +86,7 @@  EXPORT_SYMBOL(efi_enabled);

 static int __init setup_noefi(char *arg)
 {
-	clear_bit(EFI_BOOT, &x86_efi_facility);
+	clear_bit(EFI_RUNTIME_SERVICES, &x86_efi_facility);
 	return 0;
 }
 early_param("noefi", setup_noefi);