From 50255363cbf0555e0f09adfb327189bd7a4be9da Mon Sep 17 00:00:00 2001 From: Jian J Wang Date: Thu, 7 Dec 2017 20:17:49 +0800 Subject: [PATCH] MdeModulePkg/DxeIpl: Enable paging for Stack Guard Stack guard feature makes use of paging mechanism to monitor if there's a stack overflow occurred during boot. This patch will check setting of PCD PcdCpuStackGuard. If it's TRUE, DxeIpl will setup page table and set the page at which the stack base locates to be NOT PRESENT. If stack is used up and memory access cross into the last page of it, #PF exception will be triggered. Cc: Star Zeng Cc: Eric Dong Cc: Jiewen Yao Suggested-by: Ayellet Wolman Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang Reviewed-by: Jeff Fan Reviewed-by: Jiewen.yao@intel.com --- MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf | 5 +- .../Core/DxeIplPeim/Ia32/DxeLoadFunc.c | 4 ++ .../Core/DxeIplPeim/X64/DxeLoadFunc.c | 1 + .../Core/DxeIplPeim/X64/VirtualMemory.c | 51 ++++++++++++++----- 4 files changed, 46 insertions(+), 15 deletions(-) diff --git a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf index a1b8748432..ba1d9c6b05 100644 --- a/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf +++ b/MdeModulePkg/Core/DxeIplPeim/DxeIpl.inf @@ -49,7 +49,7 @@ [Sources.X64] X64/VirtualMemory.h X64/VirtualMemory.c - X64/DxeLoadFunc.c + X64/DxeLoadFunc.c [Sources.IPF] Ipf/DxeLoadFunc.c @@ -117,6 +117,7 @@ gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrMask ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask ## CONSUMES + gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard ## CONSUMES [Pcd.IA32,Pcd.X64,Pcd.ARM,Pcd.AARCH64] gEfiMdeModulePkgTokenSpaceGuid.PcdSetNxForStack ## SOMETIMES_CONSUMES @@ -132,7 +133,7 @@ # # [Hob] # MEMORY_ALLOCATION ## SOMETIMES_PRODUCES # MEMORY_ALLOCATION_MODULE for DxeCore -# MEMORY_ALLOCATION ## SOMETIMES_PRODUCES # New Stack HoB +# MEMORY_ALLOCATION ## SOMETIMES_PRODUCES # New Stack HoB # MEMORY_ALLOCATION ## SOMETIMES_PRODUCES # Old Stack HOB # # [Hob.IPF] diff --git a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c index 5649265367..441096ad0f 100644 --- a/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c +++ b/MdeModulePkg/Core/DxeIplPeim/Ia32/DxeLoadFunc.c @@ -235,6 +235,10 @@ ToBuildPageTable ( return TRUE; } + if (PcdGetBool (PcdCpuStackGuard)) { + return TRUE; + } + if (PcdGetBool (PcdSetNxForStack) && IsExecuteDisableBitAvailable ()) { return TRUE; } diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c b/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c index f613221b81..b75a4489bf 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c +++ b/MdeModulePkg/Core/DxeIplPeim/X64/DxeLoadFunc.c @@ -95,6 +95,7 @@ HandOffToDxeCore ( // for the DxeIpl and the DxeCore are both X64. // ASSERT (PcdGetBool (PcdSetNxForStack) == FALSE); + ASSERT (PcdGetBool (PcdCpuStackGuard) == FALSE); } // diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c index 29b6205e88..7f63144510 100644 --- a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c +++ b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c @@ -117,6 +117,39 @@ EnableExecuteDisableBit ( AsmWriteMsr64 (0xC0000080, MsrRegisters); } +/** + The function will check if page table entry should be splitted to smaller + granularity. + + @retval TRUE Page table should be split. + @retval FALSE Page table should not be split. +**/ +BOOLEAN +ToSplitPageTable ( + IN EFI_PHYSICAL_ADDRESS Address, + IN UINTN Size, + IN EFI_PHYSICAL_ADDRESS StackBase, + IN UINTN StackSize + ) +{ + if (IsNullDetectionEnabled () && Address == 0) { + return TRUE; + } + + if (PcdGetBool (PcdCpuStackGuard)) { + if (StackBase >= Address && StackBase < (Address + Size)) { + return TRUE; + } + } + + if (PcdGetBool (PcdSetNxForStack)) { + if ((Address < StackBase + StackSize) && ((Address + Size) > StackBase)) { + return TRUE; + } + } + + return FALSE; +} /** Split 2M page to 4K. @@ -160,7 +193,8 @@ Split2MPageTo4K ( PageTableEntry->Uint64 = (UINT64) PhysicalAddress4K | AddressEncMask; PageTableEntry->Bits.ReadWrite = 1; - if (IsNullDetectionEnabled () && PhysicalAddress4K == 0) { + if ((IsNullDetectionEnabled () && PhysicalAddress4K == 0) || + (PcdGetBool (PcdCpuStackGuard) && PhysicalAddress4K == StackBase)) { PageTableEntry->Bits.Present = 0; } else { PageTableEntry->Bits.Present = 1; @@ -214,10 +248,7 @@ Split1GPageTo2M ( PhysicalAddress2M = PhysicalAddress; for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PhysicalAddress2M += SIZE_2MB) { - if ((IsNullDetectionEnabled () && PhysicalAddress2M == 0) - || (PcdGetBool (PcdSetNxForStack) - && (PhysicalAddress2M < StackBase + StackSize) - && ((PhysicalAddress2M + SIZE_2MB) > StackBase))) { + if (ToSplitPageTable (PhysicalAddress2M, SIZE_2MB, StackBase, StackSize)) { // // Need to split this 2M page that covers NULL or stack range. // @@ -359,10 +390,7 @@ CreateIdentityMappingPageTables ( PageDirectory1GEntry = (VOID *) PageDirectoryPointerEntry; for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectory1GEntry++, PageAddress += SIZE_1GB) { - if ((IsNullDetectionEnabled () && PageAddress == 0) - || (PcdGetBool (PcdSetNxForStack) - && (PageAddress < StackBase + StackSize) - && ((PageAddress + SIZE_1GB) > StackBase))) { + if (ToSplitPageTable (PageAddress, SIZE_1GB, StackBase, StackSize)) { Split1GPageTo2M (PageAddress, (UINT64 *) PageDirectory1GEntry, StackBase, StackSize); } else { // @@ -391,10 +419,7 @@ CreateIdentityMappingPageTables ( PageDirectoryPointerEntry->Bits.Present = 1; for (IndexOfPageDirectoryEntries = 0; IndexOfPageDirectoryEntries < 512; IndexOfPageDirectoryEntries++, PageDirectoryEntry++, PageAddress += SIZE_2MB) { - if ((IsNullDetectionEnabled () && PageAddress == 0) - || (PcdGetBool (PcdSetNxForStack) - && (PageAddress < StackBase + StackSize) - && ((PageAddress + SIZE_2MB) > StackBase))) { + if (ToSplitPageTable (PageAddress, SIZE_2MB, StackBase, StackSize)) { // // Need to split this 2M page that covers NULL or stack range. // -- 2.39.2