Ring3: Fixed buggy timer interrupt handling for AARCH64.

acidanthera · Sep 27, 2024 · 27556a1 · 27556a1
1 parent e4c26e4
commit 27556a1
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Showing 3 changed files with 2 additions and 7 deletions.
diff --git a/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S b/ArmPkg/Library/ArmExceptionLib/AArch64/ExceptionSupport.S
@@ -311,7 +311,7 @@ ASM_PFX(CommonExceptionEntry):
   ldp      x24, x25, [sp, #0xc0]
   ldp      x26, x27, [sp, #0xd0]
   // Preserve return value for SVC.
-  mrs      x1, esr_el1
+  ldr      x1, [x28, #(FP_CONTEXT_SIZE + 0x18)] // Exception syndrome register
   lsr      x1, x1, #26
   and      x1, x1, #0x3F
   cmp      x1, #0x15

diff --git a/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c b/ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c
@@ -276,6 +276,7 @@ CommonCExceptionHandler (
   if (ExceptionType <= gMaxExceptionNumber) {
     if (gExceptionHandlers[ExceptionType]) {
       gExceptionHandlers[ExceptionType](ExceptionType, SystemContext);
+      SystemContext.SystemContextAArch64->ESR = 0;
       return EFI_SUCCESS;
     }
   } else {

diff --git a/MdeModulePkg/Core/Dxe/SysCall/AARCH64/CoreBootServices.S b/MdeModulePkg/Core/Dxe/SysCall/AARCH64/CoreBootServices.S
@@ -107,7 +107,6 @@ ASM_FUNC(ArmCallRing3)
   //
   msr  spsr_el1, x1
   isb
-  dsb  sy
   eret
 
 //------------------------------------------------------------------------------
@@ -119,11 +118,6 @@ ASM_FUNC(ArmCallRing3)
 //   );
 //------------------------------------------------------------------------------
 ASM_FUNC(ReturnToCore)
-  // Zero Exception Syndrome Register to prevent QEMU from random crashing.
-  msr  esr_el1, xzr
-  msr  spsr_el1, xzr
-  msr  elr_el1, xzr
-  msr  far_el1, xzr
   // Switch to Core Stack.
   mov  sp, x1
   // Restore registers and Stack.