Align the top of the stack correctly when the PEI Core calls SwitchStack()

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@2022 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 6 insertions, 4 deletions

diff --git a/EdkModulePkg/Core/Pei/Dispatcher/Dispatcher.c b/EdkModulePkg/Core/Pei/Dispatcher/Dispatcher.c
index b0de859073..ccd840d376 100644
--- a/EdkModulePkg/Core/Pei/Dispatcher/Dispatcher.c
+++ b/EdkModulePkg/Core/Pei/Dispatcher/Dispatcher.c
@@ -63,6 +63,7 @@ Returns:
   BOOLEAN                           NextFvFound;

   EFI_FIRMWARE_VOLUME_HEADER        *NextFvAddress;

   EFI_FIRMWARE_VOLUME_HEADER        *DefaultFvAddress;

+  VOID                              *TopOfStack;

   //

   // Debug data for uninstalled Peim list

   //

@@ -204,15 +205,16 @@ Returns:
                 PrivateDataInMem = (UINTN) TransferOldDataToNewDataRange (PrivateData);

                 ASSERT (PrivateDataInMem != 0);

                 //

-                //Subtract 0x10 from the 4th parameter indicating the new stack base,

-                //in order to provide buffer protection against possible illegal stack

-                //access that might corrupt the stack.

+                // Adjust the top of stack to be aligned at CPU_STACK_ALIGNMENT

                 //

+                TopOfStack = (VOID *)((UINTN)PrivateData->StackBase + (UINTN)PrivateData->StackSize - CPU_STACK_ALIGNMENT);

+                TopOfStack = ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);

+

                 PeiSwitchStacks (

                   (SWITCH_STACK_ENTRY_POINT)(UINTN)TempPtr.Raw,

                   PeiStartupDescriptor,

                   (VOID*)PrivateDataInMem,

-                  (VOID*)((UINTN)PrivateData->StackBase + (UINTN)PrivateData->StackSize),

+                  TopOfStack,

                   (VOID*)(UINTN)PrivateData->StackBase

                   );

               }