From: Jeff Fan <jeff....@intel.com> The commit 8b9311 changed the zeroing of mSmmMpSyncData of type SMM_DISPATCHER_MP_SYNC_DATA by the following patch. - ZeroMem (mSmmMpSyncData, mSmmMpSyncDataSize); + mSmmMpSyncData->SwitchBsp = FALSE;
mSmmMpSyncDataSize not only includes SMM_DISPATCHER_MP_SYNC_DATA, but also includes the SMM_CPU_DATA_BLOCK array and one BOOLEAN variable array as shown here: mSmmMpSyncDataSize = sizeof (SMM_DISPATCHER_MP_SYNC_DATA) + (sizeof (SMM_CPU_DATA_BLOCK) + sizeof (BOOLEAN)) * gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus; This patch restores the original ZeroMem() to clear all CPU Sync data. The commit 8b9311 may cause unexpected behavior. Cc: Feng Tian <feng.t...@intel.com> Cc: Michael Kinney <michael.d.kin...@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan <jeff....@intel.com> --- UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c index 5ba0514..fe9076b 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c @@ -1276,7 +1276,10 @@ InitializeMpSyncData ( UINTN CpuIndex; if (mSmmMpSyncData != NULL) { - mSmmMpSyncData->SwitchBsp = FALSE; + // + // mSmmMpSyncDataSize includes SMM_DISPATCHER_MP_SYNC_DATA and SMM_CPU_DATA_BLOCK range + // + ZeroMem (mSmmMpSyncData, mSmmMpSyncDataSize); mSmmMpSyncData->CpuData = (SMM_CPU_DATA_BLOCK *)((UINT8 *)mSmmMpSyncData + sizeof (SMM_DISPATCHER_MP_SYNC_DATA)); mSmmMpSyncData->CandidateBsp = (BOOLEAN *)(mSmmMpSyncData->CpuData + gSmmCpuPrivate->SmmCoreEntryContext.NumberOfCpus); if (FeaturePcdGet (PcdCpuSmmEnableBspElection)) { -- 2.6.3.windows.1 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel