Hi Ard,
No worries. Liming has helped to merge these patches here: MM
communicate functionality in variable policy by lgao4 · Pull
Request #2443 · tianocore/edk2 (github.com). Thanks for
checking back.
Regards,
Kun
On Mon, 13 Dec 2021 at 19:23, Kun Qin <kuqin12@gmail.com> wrote:Hi ArmPkg and MdeModulePkg maintainers, Now that the hard freeze is lifted, could you please provide some feedback on these patches when you have a chance?My apologies for not responding to these changes. If these patches are still relevant, please rebase and resend them.On 12/06/2021 10:41, Ard Biesheuvel wrote:On Mon, 6 Dec 2021 at 19:35, Kun Qin <kuqin12@gmail.com> wrote:Hi ArmPkg and MdeModulePkg maintainers, It has been a week since the patches were sent. Could you please review the changes and let me know if there is any feedback? Any input is appreciated.As far as I know, we are still in hard freeze for the upcoming stable tag.On 11/29/2021 16:39, Kun Qin via groups.io wrote:REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3709 REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3751 Currently, setups with variable policy operations used together with MM communicate from ArmPkg could fail with `EFI_INVALID_PARAMETER`. This was due to the errors from 2 following aspects: 1. For variable policy implementations in MdeModulePkg, the DXE runtime agent would communicate to MM to disable, register or query policies. However, during these operations, the MessageLength calculation is including MM communicate header. This could lead to MM agent read data across the given buffer boundary and/or trigger other errors. 2. On the other hand, current MM communicate routine from ArmPkg would fail the function if the input message length does not equal to input buffer size. As defined in PI specification, the `CommSize`, when as input, should stand for "The size of the data buffer being passed in", which would mean the maximal number of bytes `CommBuffer` can hold. In turn, the value of this input parameter can be used for MM handlers to determine whether the output data is too large to fit in this buffer. Enforcing the incoming buffer to hold exactly the number of used bytes mismatches with the PI spec description. This change fix MessageLength field calculation from variable policy and updated input argument inspections from MM communicate routine in ArmPkg to match PI spec descriptions. Patch v1 branch: https://github.com/kuqin12/edk2/tree/mm_communicate_check Cc: Jian J Wang <jian.j.wang@intel.com> Cc: Liming Gao <gaoliming@byosoft.com.cn> Cc: Hao A Wu <hao.a.wu@intel.com> Cc: Leif Lindholm <leif@nuviainc.com> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org> Cc: Bret Barkelew <Bret.Barkelew@microsoft.com> Cc: Michael Kubacki <michael.kubacki@microsoft.com> Kun Qin (2): MdeModulePkg: VariableSmmRuntimeDxe: Fix Variable Policy Message Length ArmPkg: MmCommunicationDxe: Update MM communicate input arguments checks ArmPkg/Drivers/MmCommunicationDxe/MmCommunication.c | 44 ++++++++++++-------- MdeModulePkg/Universal/Variable/RuntimeDxe/VariablePolicySmmDxe.c | 10 ++--- 2 files changed, 32 insertions(+), 22 deletions(-)