| Message ID | 1410818882-8035-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 08fa7df..03e74b3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1613,6 +1613,7 @@ config EFI config EFI_STUB bool "EFI stub support" depends on EFI + select RELOCATABLE ---help--- This kernel feature allows a bzImage to be loaded directly by EFI firmware without the use of a bootloader.
This is a note to let you know that I have just added a patch titled x86/efi: Enforce CONFIG_RELOCATABLE for EFI boot stub to the linux-3.13.y-queue branch of the 3.13.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-3.13.y-queue This patch is scheduled to be released in version 3.13.11.7. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.13.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From e8a38a413b08c3a672d201402d90bf01a2994c4b Mon Sep 17 00:00:00 2001 From: Matt Fleming <matt.fleming@intel.com> Date: Fri, 11 Jul 2014 08:45:25 +0100 Subject: x86/efi: Enforce CONFIG_RELOCATABLE for EFI boot stub MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 7b2a583afb4ab894f78bc0f8bd136e96b6499a7e upstream. Without CONFIG_RELOCATABLE the early boot code will decompress the kernel to LOAD_PHYSICAL_ADDR. While this may have been fine in the BIOS days, that isn't going to fly with UEFI since parts of the firmware code/data may be located at LOAD_PHYSICAL_ADDR. Straying outside of the bounds of the regions we've explicitly requested from the firmware will cause all sorts of trouble. Bruno reports that his machine resets while trying to decompress the kernel image. We already go to great pains to ensure the kernel is loaded into a suitably aligned buffer, it's just that the address isn't necessarily LOAD_PHYSICAL_ADDR, because we can't guarantee that address isn't in-use by the firmware. Explicitly enforce CONFIG_RELOCATABLE for the EFI boot stub, so that we can load the kernel at any address with the correct alignment. Reported-by: Bruno Prémont <bonbons@linux-vserver.org> Tested-by: Bruno Prémont <bonbons@linux-vserver.org> Cc: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/x86/Kconfig | 1 + 1 file changed, 1 insertion(+) -- 1.9.1