From: AJFISH <AJFISH@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 8 Jan 2010 23:07:33 +0000 (+0000)
Subject: Fixed a bug in the HardwareInterrupt handler that would blow the stack if you reenabl... 
X-Git-Tag: edk2-stable201903~16623
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=d213712d4f858efd5cb43faa39c6d940829c9363;hp=2127579be198425ffd94e2b0be68f66d0dba1a5a

Fixed a bug in the HardwareInterrupt handler that would blow the stack if you reenable interrupts in the TimerHandler. It should be noted this happens as the TimerHandler raises and restores TPL for the timer tick used by the DXE Core. There was some work around code in the CPU driver to prevent interrupts from being enabled while handling exceptions. This has been removed.


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9701 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/ArmPkg/Drivers/CpuDxe/CpuDxe.c b/ArmPkg/Drivers/CpuDxe/CpuDxe.c
index 2b43d2a9c9..d3f0ff505d 100644
--- a/ArmPkg/Drivers/CpuDxe/CpuDxe.c
+++ b/ArmPkg/Drivers/CpuDxe/CpuDxe.c
@@ -14,7 +14,6 @@
 
 #include "CpuDxe.h"
 
-BOOLEAN gExceptionContext = FALSE;
 BOOLEAN mInterruptState   = FALSE;
 
 EFI_STATUS
@@ -49,9 +48,7 @@ CpuEnableInterrupt (
   IN EFI_CPU_ARCH_PROTOCOL          *This
   )
 {
-  if (!gExceptionContext) {
-    ArmEnableInterrupts ();
-  }
+  ArmEnableInterrupts ();
 
   mInterruptState  = TRUE;
   return EFI_SUCCESS;
@@ -64,9 +61,7 @@ CpuDisableInterrupt (
   IN EFI_CPU_ARCH_PROTOCOL          *This
   )
 {
-  if (!gExceptionContext) {
-    ArmDisableInterrupts ();
-  }
+  ArmDisableInterrupts ();
 
   mInterruptState = FALSE;
   return EFI_SUCCESS;
diff --git a/ArmPkg/Drivers/CpuDxe/Exception.c b/ArmPkg/Drivers/CpuDxe/Exception.c
index 8859ca8667..9910bd2b88 100644
--- a/ArmPkg/Drivers/CpuDxe/Exception.c
+++ b/ArmPkg/Drivers/CpuDxe/Exception.c
@@ -15,8 +15,6 @@
 #include "CpuDxe.h" 
 #include <Library/CacheMaintenanceLib.h>
 
-extern BOOLEAN gExceptionContext;
-
 VOID
 ExceptionHandlersStart (
   VOID
@@ -142,8 +140,7 @@ CommonCExceptionHandler (
 {
   BOOLEAN Dispatched = FALSE;
  
-  gExceptionContext = TRUE; 
-  
+ 
   if (ExceptionType <= MAX_ARM_EXCEPTION) {
     if (gDebuggerExceptionHandlers[ExceptionType]) {
       //
@@ -162,8 +159,6 @@ CommonCExceptionHandler (
     ASSERT (FALSE);
   }
 
-  gExceptionContext = FALSE; 
-
   if (Dispatched) {
     //
     // We did work so this was an expected ExceptionType
diff --git a/BeagleBoardPkg/InterruptDxe/HardwareInterrupt.c b/BeagleBoardPkg/InterruptDxe/HardwareInterrupt.c
index 3e69515dfe..c87d564063 100644
--- a/BeagleBoardPkg/InterruptDxe/HardwareInterrupt.c
+++ b/BeagleBoardPkg/InterruptDxe/HardwareInterrupt.c
@@ -234,12 +234,16 @@ IrqInterruptHandler (
   
   Vector = MmioRead32(INTCPS_SIR_IRQ) & INTCPS_SIR_IRQ_MASK;
 
+  // Needed to prevent infinite nesting if Time Driver lowers TPL
+  MmioWrite32(INTCPS_CONTROL, INTCPS_CONTROL_NEWIRQAGR);
+
   InterruptHandler = gRegisteredInterruptHandlers[Vector];
   if (InterruptHandler != NULL) {
     // Call the registered interrupt handler.
     InterruptHandler(Vector, SystemContext);
   }
   
+  // Needed to clear after running the handler
   MmioWrite32(INTCPS_CONTROL, INTCPS_CONTROL_NEWIRQAGR);
 }