[edk2-devel] [PATCH 1/2] UefiCpuPkg/CpuDxe: Return correct interrupt state

["Ni, Ray" <ray.ni@intel.com>]

CpuDxe driver uses a global C variable to record the interrupt state.
The state variable is updated every time CpuArch.EnableInterrupt() or
CpuArch.DisableInterrupt() is called.
CpuArch.GetInterruptState() simply returns the state variable.

But when CpuArch.GetInterruptState() is called in the interrupt
context, even the interrupt state is enabled before interrupt
happens, because the interrupt is not disabled through
CpuArch.DisableInterrupts(), CpuArch.GetInterruptState() still
returns that the interrupt state is enabled.
It's not correct.

The commit removes the C global variable and always reads the
interrupt state from CPU register.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
---
 UefiCpuPkg/CpuDxe/CpuDxe.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.c b/UefiCpuPkg/CpuDxe/CpuDxe.c
index bf03978710..0349c761ff 100644
--- a/UefiCpuPkg/CpuDxe/CpuDxe.c
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.c
@@ -15,8 +15,7 @@
 //
 // Global Variables
 //
-BOOLEAN     InterruptState = FALSE;
-EFI_HANDLE  mCpuHandle     = NULL;
+EFI_HANDLE  mCpuHandle = NULL;
 BOOLEAN     mIsFlushingGCD;
 BOOLEAN     mIsAllocatingPageTable = FALSE;
 UINT64      mTimerPeriod           = 0;
@@ -89,8 +88,6 @@ CpuEnableInterrupt (
   )
 {
   EnableInterrupts ();
-
-  InterruptState = TRUE;
   return EFI_SUCCESS;
 }
 
@@ -110,8 +107,6 @@ CpuDisableInterrupt (
   )
 {
   DisableInterrupts ();
-
-  InterruptState = FALSE;
   return EFI_SUCCESS;
 }
 
@@ -136,7 +131,8 @@ CpuGetInterruptState (
     return EFI_INVALID_PARAMETER;
   }
 
-  *State = InterruptState;
+  *State = GetInterruptState ();
+
   return EFI_SUCCESS;
 }
 
-- 
2.39.1.windows.1



-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#116166): https://edk2.groups.io/g/devel/message/116166
Mute This Topic: https://groups.io/mt/104642316/7686176
Group Owner: devel+owner@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io]
-=-=-=-=-=-=-=-=-=-=-=-