From: Michael Kubacki <michael.a.kuba...@intel.com> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1614
Moves the GDT and IDT to permanent memory in a memory discovered callback. This is done to ensure the GDT and IDT authenticated in pre-memory is not fetched from outside a verified location after the permanent memory transition. Cc: Eric Dong <eric.d...@intel.com> Cc: Ray Ni <ray...@intel.com> Cc: Laszlo Ersek <ler...@redhat.com> Cc: Rahul Kumar <rahul1.ku...@intel.com> Signed-off-by: Michael Kubacki <michael.a.kuba...@intel.com> --- UefiCpuPkg/CpuMpPei/CpuMpPei.c | 40 ++++++++++++++++++- UefiCpuPkg/CpuMpPei/CpuMpPei.h | 13 ++++++ UefiCpuPkg/CpuMpPei/CpuPaging.c | 14 +++++-- .../Ia32/ArchExceptionHandler.c | 4 +- .../SecPeiCpuException.c | 2 +- 5 files changed, 65 insertions(+), 8 deletions(-) diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c index 07ccbe7c6a91..2d6f1bc98851 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c @@ -429,6 +429,44 @@ GetGdtr ( AsmReadGdtr ((IA32_DESCRIPTOR *)Buffer); } +/** + Migrates the Global Descriptor Table (GDT) to permanent memory. + + @retval EFI_SUCCESS The GDT was migrated successfully. + @retval EFI_OUT_OF_RESOURCES The GDT could not be migrated due to lack of available memory. + +**/ +EFI_STATUS +EFIAPI +MigrateGdt ( + VOID + ) +{ + EFI_STATUS Status; + UINTN GdtBufferSize; + IA32_DESCRIPTOR Gdtr; + UINT8 *GdtBuffer; + + AsmReadGdtr ((IA32_DESCRIPTOR *) &Gdtr); + GdtBufferSize = sizeof (IA32_TSS_DESCRIPTOR) + Gdtr.Limit + 1; + + Status = PeiServicesAllocatePool ( + GdtBufferSize, + (VOID **) &GdtBuffer + ); + ASSERT (GdtBuffer != NULL); + if (EFI_ERROR (Status)) { + return EFI_OUT_OF_RESOURCES; + } + + GdtBuffer = ALIGN_POINTER (GdtBuffer, sizeof (IA32_TSS_DESCRIPTOR)); + CopyMem ((VOID *) (UINTN) GdtBuffer, (VOID *) Gdtr.Base, Gdtr.Limit + 1); + Gdtr.Base = (UINT32)(UINTN) GdtBuffer; + AsmWriteGdtr (&Gdtr); + + return EFI_SUCCESS; +} + /** Initializes CPU exceptions handlers for the sake of stack switch requirement. @@ -644,7 +682,7 @@ InitializeCpuMpWorker ( &gEfiVectorHandoffInfoPpiGuid, 0, NULL, - (VOID **)&VectorHandoffInfoPpi + (VOID **) &VectorHandoffInfoPpi ); if (Status == EFI_SUCCESS) { VectorInfo = VectorHandoffInfoPpi->Info; diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.h b/UefiCpuPkg/CpuMpPei/CpuMpPei.h index 7d5c527d6006..5dc956409594 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.h +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.h @@ -397,6 +397,19 @@ SecPlatformInformation2 ( OUT EFI_SEC_PLATFORM_INFORMATION_RECORD2 *PlatformInformationRecord2 ); +/** + Migrates the Global Descriptor Table (GDT) to permanent memory. + + @retval EFI_SUCCESS The GDT was migrated successfully. + @retval EFI_OUT_OF_RESOURCES The GDT could not be migrated due to lack of available memory. + +**/ +EFI_STATUS +EFIAPI +MigrateGdt ( + VOID + ); + /** Initializes MP and exceptions handlers. diff --git a/UefiCpuPkg/CpuMpPei/CpuPaging.c b/UefiCpuPkg/CpuMpPei/CpuPaging.c index a462e7ee1e38..d0cbebf70bbf 100644 --- a/UefiCpuPkg/CpuMpPei/CpuPaging.c +++ b/UefiCpuPkg/CpuMpPei/CpuPaging.c @@ -152,7 +152,7 @@ GetPhysicalAddressWidth ( Get the type of top level page table. @retval Page512G PML4 paging. - @retval Page1G PAE paing. + @retval Page1G PAE paging. **/ PAGE_ATTRIBUTE @@ -582,7 +582,7 @@ SetupStackGuardPage ( } /** - Enabl/setup stack guard for each processor if PcdCpuStackGuard is set to TRUE. + Enable/setup stack guard for each processor if PcdCpuStackGuard is set to TRUE. Doing this in the memory-discovered callback is to make sure the Stack Guard feature to cover as most PEI code as possible. @@ -602,8 +602,14 @@ MemoryDiscoveredPpiNotifyCallback ( IN VOID *Ppi ) { - EFI_STATUS Status; - BOOLEAN InitStackGuard; + EFI_STATUS Status; + BOOLEAN InitStackGuard; + BOOLEAN InterruptState; + + InterruptState = SaveAndDisableInterrupts (); + Status = MigrateGdt (); + ASSERT_EFI_ERROR (Status); + SetInterruptState (InterruptState); // // Paging must be setup first. Otherwise the exception TSS setup during MP diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c index 1aafb7dac139..903449e0daa9 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/Ia32/ArchExceptionHandler.c @@ -18,8 +18,8 @@ **/ VOID ArchUpdateIdtEntry ( - IN IA32_IDT_GATE_DESCRIPTOR *IdtEntry, - IN UINTN InterruptHandler + OUT IA32_IDT_GATE_DESCRIPTOR *IdtEntry, + IN UINTN InterruptHandler ) { IdtEntry->Bits.OffsetLow = (UINT16)(UINTN)InterruptHandler; diff --git a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c index 20148db74cf8..d4ae153c5742 100644 --- a/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c +++ b/UefiCpuPkg/Library/CpuExceptionHandlerLib/SecPeiCpuException.c @@ -87,7 +87,7 @@ InitializeCpuExceptionHandlers ( IdtEntryCount = (IdtDescriptor.Limit + 1) / sizeof (IA32_IDT_GATE_DESCRIPTOR); if (IdtEntryCount > CPU_EXCEPTION_NUM) { // - // CPU exeption library only setup CPU_EXCEPTION_NUM exception handler at most + // CPU exception library only setup CPU_EXCEPTION_NUM exception handler at most // IdtEntryCount = CPU_EXCEPTION_NUM; } -- 2.25.1.windows.1 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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