If the associated PCD is set to TRUE, use the memory attribute PPI to remap the stack non-executable. This provides a generic method for doing so, which will be used by ARM and AArch64 as well once they move to the generic DxeIpl handoff implementation. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Oliver Smith-Denny <osde@linux.microsoft.com> Reviewed-by: Michael Kubacki <michael.kubacki@microsoft.com> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
		
			
				
	
	
		
			89 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /** @file
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|   Generic version of arch-specific functionality for DxeLoad.
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| 
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| Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
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| Copyright (c) 2023, Google, LLC. All rights reserved.<BR>
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| SPDX-License-Identifier: BSD-2-Clause-Patent
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| 
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| **/
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| 
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| #include "DxeIpl.h"
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| 
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| #include <Ppi/MemoryAttribute.h>
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| 
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| /**
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|    Transfers control to DxeCore.
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| 
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|    This function performs a CPU architecture specific operations to execute
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|    the entry point of DxeCore with the parameters of HobList.
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|    It also installs EFI_END_OF_PEI_PPI to signal the end of PEI phase.
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| 
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|    @param DxeCoreEntryPoint         The entry point of DxeCore.
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|    @param HobList                   The start of HobList passed to DxeCore.
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| 
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| **/
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| VOID
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| HandOffToDxeCore (
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|   IN EFI_PHYSICAL_ADDRESS  DxeCoreEntryPoint,
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|   IN EFI_PEI_HOB_POINTERS  HobList
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|   )
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| {
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|   VOID                        *BaseOfStack;
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|   VOID                        *TopOfStack;
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|   EFI_STATUS                  Status;
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|   EDKII_MEMORY_ATTRIBUTE_PPI  *MemoryPpi;
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| 
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|   //
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|   // Allocate 128KB for the Stack
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|   //
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|   BaseOfStack = AllocatePages (EFI_SIZE_TO_PAGES (STACK_SIZE));
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|   ASSERT (BaseOfStack != NULL);
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| 
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|   if (PcdGetBool (PcdSetNxForStack)) {
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|     Status = PeiServicesLocatePpi (
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|                &gEdkiiMemoryAttributePpiGuid,
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|                0,
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|                NULL,
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|                (VOID **)&MemoryPpi
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|                );
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|     ASSERT_EFI_ERROR (Status);
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| 
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|     Status = MemoryPpi->SetPermissions (
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|                           MemoryPpi,
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|                           (UINTN)BaseOfStack,
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|                           STACK_SIZE,
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|                           EFI_MEMORY_XP,
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|                           EFI_MEMORY_XP
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|                           );
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|     ASSERT_EFI_ERROR (Status);
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|   }
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| 
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|   //
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|   // Compute the top of the stack we were allocated. Pre-allocate a UINTN
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|   // for safety.
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|   //
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|   TopOfStack = (VOID *)((UINTN)BaseOfStack + EFI_SIZE_TO_PAGES (STACK_SIZE) * EFI_PAGE_SIZE - CPU_STACK_ALIGNMENT);
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|   TopOfStack = ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);
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| 
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|   //
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|   // End of PEI phase signal
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|   //
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|   Status = PeiServicesInstallPpi (&gEndOfPeiSignalPpi);
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|   ASSERT_EFI_ERROR (Status);
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| 
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|   //
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|   // Update the contents of BSP stack HOB to reflect the real stack info passed to DxeCore.
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|   //
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|   UpdateStackHob ((EFI_PHYSICAL_ADDRESS)(UINTN)BaseOfStack, STACK_SIZE);
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| 
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|   //
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|   // Transfer the control to the entry point of DxeCore.
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|   //
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|   SwitchStack (
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|     (SWITCH_STACK_ENTRY_POINT)(UINTN)DxeCoreEntryPoint,
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|     HobList.Raw,
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|     NULL,
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|     TopOfStack
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|     );
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| }
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