[edk2-devel] [PATCH 0/5] StandaloneMmPkg: make StMM core relocatable
Ilias Apalodimas
ilias.apalodimas at linaro.org
Wed Jun 10 10:21:48 UTC 2020
Hi Ard,
Tested on QEMU with the op-tee patches i mentioned in my RFC [1]
Everything seems to work correctly
[1] https://edk2.groups.io/g/devel/message/60835
On Wed, Jun 10, 2020 at 10:17:35AM +0200, Ard Biesheuvel wrote:
> It is not always possible to deploy the standalone MM core in a way where
> the runtime address is known at build time. This does not matter for most
> modules, since they are relocated at dispatch time. However, for the MM
> core itself, it means we need to do some extra work to relocate the image
> in place if it ends up at a different offset than expected.
>
> On AARCH64, the standalone MM stack is deployed inside a non-privileged
> secure world container which only has limited control over its memory
> mappings, and so we need to ensure that the executable code itself is
> free of absolute quantities that need to be fixed up. This is very similar
> to how shared libraries are constructed, given that pages can only be
> shared between processes if they are not modified, even by the dynamic
> loader. So we can use this support to emit the standaline MM core in a
> way that guarantees that the executable code does not need to modify
> itself (patch #4)
>
> Patch #5 adds the actual code to perform the self relocation after the
> .data section has been made writable and non-executable. Note that the
> PE/COFF library code modifies the header in place, and so in the case
> where we need to perform the runtime relocation, we need to remap the
> header page writable and non-executable as well.
>
> The remaining patches are optimizations and fixes I picked up along
> the way.
>
> Cc: Michael D Kinney <michael.d.kinney at intel.com>
> Cc: Liming Gao <liming.gao at intel.com>
> Cc: Jiewen Yao <jiewen.yao at intel.com>
> Cc: Sami Mujawar <sami.mujawar at arm.com>
> Cc: Ilias Apalodimas <ilias.apalodimas at linaro.org>
>
> Ard Biesheuvel (5):
> MdePkg/BasePrintLib: avoid absolute addresses for error strings
> StandaloneMmPkg/Core: fix bogus FV pointer in DEBUG string
> StandaloneMmPkg/Core: add missing GUID reference
> StandaloneMmPkg: generate position independent code for StMM core
> StandaloneMmPkg/StandaloneMmCoreEntryPoint: relocate StMM core on the
> fly
>
> StandaloneMmPkg/Core/StandaloneMmCore.inf | 5 +++++
> StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/StandaloneMmCoreEntryPoint.inf | 3 +++
> StandaloneMmPkg/Include/Library/AArch64/StandaloneMmCoreEntryPoint.h | 2 ++
> MdePkg/Library/BasePrintLib/PrintLibInternal.c | 2 +-
> StandaloneMmPkg/Core/Dispatcher.c | 2 +-
> StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/SetPermissions.c | 11 +++++++---
> StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/StandaloneMmCoreEntryPoint.c | 22 ++++++++++++++++++++
> 7 files changed, 42 insertions(+), 5 deletions(-)
>
> --
> 2.26.2
>
Tested-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#61068): https://edk2.groups.io/g/devel/message/61068
Mute This Topic: https://groups.io/mt/74792287/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-
More information about the edk2-devel-archive
mailing list