Ring3: Fixed LibraryConstructors' initialization and

allowed user to access ports.
acidanthera · Jan 18, 2024 · cff574f · cff574f
1 parent d2e5746
commit cff574f
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diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf b/MdeModulePkg/Core/Dxe/DxeMain.inf
@@ -192,6 +192,8 @@
   gEfiMdeModulePkgTokenSpaceGuid.PcdImageLargeAddressLoad                   ## CONSUMES
   gEfiMdePkgTokenSpaceGuid.PcdDebugRaisePropertyMask                        ## CONSUMES
   gEfiMdePkgTokenSpaceGuid.PcdImageProtectionPolicy                         ## CONSUMES
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase                            ## CONSUMES
+  gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaSize                            ## CONSUMES
 
 # [Hob]
 # RESOURCE_DESCRIPTOR   ## CONSUMES

diff --git a/MdeModulePkg/Core/Dxe/Image/Image.c b/MdeModulePkg/Core/Dxe/Image/Image.c
@@ -1714,6 +1714,15 @@ CoreStartImage (
       TopOfStack = ALIGN_POINTER (TopOfStack, CPU_STACK_ALIGNMENT);
       // DEBUG ((DEBUG_ERROR, "RING3_CODE64_SEL = 0x%x   RING3_DATA64_SEL = 0x%x\n", (UINT16)RING3_CODE64_SEL, (UINT16)RING3_DATA64_SEL));
 
+      //
+      // Necessary fix for ProcessLibraryConstructorList() -> DxeCcProbeLibConstructor()
+      //
+      SetUefiImageMemoryAttributes (
+        FixedPcdGet32 (PcdOvmfWorkAreaBase),
+        FixedPcdGet32 (PcdOvmfWorkAreaSize),
+        EFI_MEMORY_XP | EFI_MEMORY_USER
+        );
+
       EnterUserImage (
         (SWITCH_STACK_ENTRY_POINT)(UINTN)Image->EntryPoint,
         ImageHandle,

diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
@@ -990,6 +990,10 @@ CreateIdentityMappingPageTables (
 
     Eflags.UintN   = AsmReadEflags ();
     Eflags.Bits.AC = 0;
+    //
+    // Allow user image to access ports.
+    //
+    Eflags.Bits.IOPL = 3;
     AsmWriteEflags (Eflags.UintN);
   }