[GIT PULL 0/2] EFI urgent fixes

[GIT PULL 0/2] EFI urgent fixes

[Matt Fleming]

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

Folks,

The patches in this pull request fix kernel crashes when booting Linux
on UEFI v2.5 machines with the Properties Table feature enabled.

Essentially, when this feature is enabled the firmware allocates
separate entries in the EFI memory map for the code and data sections
of PE/COFF images, whereas previously only one memory map entry would
have existed.

Because we've now got two entries that reference each other we *must*
map them into the kernel virtual address space with the same offsets
and in the same order as they appear in the EFI memory map. Failure to
do so causes the firmware to access unmapped/invalid addresses. 

These patches were intentionally kept as small as possible so that
they can be backported by distributions, aggressively.

The following changes since commit 1f93e4a96c9109378204c147b3eec0d0e8100fde:

  Linux 4.3-rc2 (2015-09-20 14:32:34 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-urgent

for you to fetch changes up to 1fa25e09ca2ce07f03bca93ad71800c312fd4951:

  arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions (2015-09-25 22:35:15 +0100)

----------------------------------------------------------------
 * arm64 bug fix for UEFI 2.5 firmware that has the Properties Table
   feature enabled. The fix avoids a kernel crash by removing the padding
   between runtime regions that we currently do in the kernel so we don't
   break the EFI's cross-region references - Ard Biesheuvel

 * Map EFI memory regions in-order on x86 so that we maintain the
   relative offset between regions and fix a crash when booting on
   UEFI 2.5 machines with the Properties Table feature enabled.

----------------------------------------------------------------
Ard Biesheuvel (1):
      arm64/efi: Don't pad between EFI_MEMORY_RUNTIME regions

Matt Fleming (1):
      x86/efi: Map EFI memmap entries in-order at runtime

 arch/arm64/kernel/efi.c                 |  3 +-
 arch/x86/platform/efi/efi.c             | 67 ++++++++++++++++++++++++-
 drivers/firmware/efi/libstub/arm-stub.c | 88 +++++++++++++++++++++++++++------
 3 files changed, 141 insertions(+), 17 deletions(-)

[GIT PULL 0/2] EFI urgent fixes

[Matt Fleming]

Folks, please pull the following two fixes that address the boot hang
issue Waiman reported here,

  https://lkml.kernel.org/r/57DF56D4.50304@hpe.com

The following changes since commit 3be7988674ab33565700a37b210f502563d932e6:

  Linux 4.8-rc7 (2016-09-18 17:27:41 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-urgent

for you to fetch changes up to 1297667083d5442aafe3e337b9413bf02b114edb:

  x86/efi: Only map RAM into EFI page tables if in mixed-mode (2016-09-20 14:53:04 +0100)

----------------------------------------------------------------
 * Fix a boot hang on large memory machines (multiple terabyte) caused
   by type conversion errors in the x86 pat code - Matt Fleming

----------------------------------------------------------------
Matt Fleming (2):
      x86/mm/pat: Prevent hang during boot when mapping pages
      x86/efi: Only map RAM into EFI page tables if in mixed-mode

 arch/x86/mm/pageattr.c         | 21 +++++++++++----------
 arch/x86/platform/efi/efi_64.c |  2 +-
 2 files changed, 12 insertions(+), 11 deletions(-)

[PATCH 2/2] x86/efi: Only map RAM into EFI page tables if in mixed-mode

[Matt Fleming]

Waiman reported that booting with CONFIG_EFI_MIXED enabled on his
multi-terabyte HP machine results in boot crashes, because the EFI
region mapping functions loop forever while trying to map those
regions describing RAM.

While this patch doesn't fix the underlying hang, there's really no
reason to map EFI_CONVENTIONAL_MEMORY regions into the EFI page tables
when mixed-mode is not in use at runtime.

Reported-by: Waiman Long <waiman.long@hpe.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
CC: Theodore Ts'o <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
 arch/x86/platform/efi/efi_64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index 677e29e29473..8dd3784eb075 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -245,7 +245,7 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 	 * text and allocate a new stack because we can't rely on the
 	 * stack pointer being < 4GB.
 	 */
-	if (!IS_ENABLED(CONFIG_EFI_MIXED))
+	if (!IS_ENABLED(CONFIG_EFI_MIXED) || efi_is_native())
 		return 0;
 
 	/*
-- 
2.9.3

Re: [GIT PULL 0/2] EFI urgent fixes

[Ingo Molnar]

* Matt Fleming <matt@codeblueprint.co.uk> wrote:

> Folks, please pull the following two fixes that address the boot hang
> issue Waiman reported here,
> 
>   https://lkml.kernel.org/r/57DF56D4.50304@hpe.com
> 
> The following changes since commit 3be7988674ab33565700a37b210f502563d932e6:
> 
>   Linux 4.8-rc7 (2016-09-18 17:27:41 -0700)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-urgent
> 
> for you to fetch changes up to 1297667083d5442aafe3e337b9413bf02b114edb:
> 
>   x86/efi: Only map RAM into EFI page tables if in mixed-mode (2016-09-20 14:53:04 +0100)
> 
> ----------------------------------------------------------------
>  * Fix a boot hang on large memory machines (multiple terabyte) caused
>    by type conversion errors in the x86 pat code - Matt Fleming
> 
> ----------------------------------------------------------------
> Matt Fleming (2):
>       x86/mm/pat: Prevent hang during boot when mapping pages
>       x86/efi: Only map RAM into EFI page tables if in mixed-mode
> 
>  arch/x86/mm/pageattr.c         | 21 +++++++++++----------
>  arch/x86/platform/efi/efi_64.c |  2 +-
>  2 files changed, 12 insertions(+), 11 deletions(-)

Pulled, thanks a lot Matt!

	Ingo

Re: [GIT PULL 0/2] EFI urgent fixes

[Waiman Long]

On 09/20/2016 10:48 AM, Matt Fleming wrote:
> Folks, please pull the following two fixes that address the boot hang
> issue Waiman reported here,
>
>    https://lkml.kernel.org/r/57DF56D4.50304@hpe.com
>
> The following changes since commit 3be7988674ab33565700a37b210f502563d932e6:
>
>    Linux 4.8-rc7 (2016-09-18 17:27:41 -0700)
>
> are available in the git repository at:
>
>    git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi.git tags/efi-urgent
>
> for you to fetch changes up to 1297667083d5442aafe3e337b9413bf02b114edb:
>
>    x86/efi: Only map RAM into EFI page tables if in mixed-mode (2016-09-20 14:53:04 +0100)
>
> ----------------------------------------------------------------
>   * Fix a boot hang on large memory machines (multiple terabyte) caused
>     by type conversion errors in the x86 pat code - Matt Fleming
>
> ----------------------------------------------------------------
> Matt Fleming (2):
>        x86/mm/pat: Prevent hang during boot when mapping pages
>        x86/efi: Only map RAM into EFI page tables if in mixed-mode
>
>   arch/x86/mm/pageattr.c         | 21 +++++++++++----------
>   arch/x86/platform/efi/efi_64.c |  2 +-
>   2 files changed, 12 insertions(+), 11 deletions(-)

Are you also going to send these fixes to the 4.6 and 4.7 stable trees 
as well?

Cheers,
Longman