Ring3: Added helper function AllocateCoreCopy(), refactored SysCall.

MdeModulePkg/Core/Dxe/DxeMain/DxeMain.c

@@ -90,7 +90,8 @@ EFI_BOOT_SERVICES  mBootServices = {
   (EFI_COPY_MEM)CopyMem,                                                                  // CopyMem
   (EFI_SET_MEM)SetMem,                                                                    // SetMem
   (EFI_CREATE_EVENT_EX)CoreCreateEventEx,                                                 // CreateEventEx
-  (EFI_ALLOCATE_RING3_PAGES)AllocateRing3Pages
+  (EFI_ALLOCATE_RING3_PAGES)AllocateRing3Pages,
+  (EFI_ALLOCATE_CORE_COPY)AllocateCopyPool
 };
 
 EFI_DXE_SERVICES  mDxeServices = {

MdePkg/Include/Library/BaseLib.h

@@ -6699,6 +6699,7 @@ AsmReadEflags (
 UINTN
 EFIAPI
 CoreBootServices (
+  IN  UINT8  Type,
   IN  UINTN  FunctionAddress,
   ...
   );

MdePkg/Include/Uefi/UefiSpec.h

@@ -229,6 +229,13 @@ EFI_STATUS
   IN OUT VOID                         **Memory
   );
 
+typedef
+VOID *
+(EFIAPI *EFI_ALLOCATE_CORE_COPY)(
+  IN UINTN       AllocationSize,
+  IN CONST VOID  *Buffer
+  );
+
 /**
   Frees memory pages.
 
@@ -2031,6 +2038,7 @@ typedef struct {
   EFI_SET_MEM                                   SetMem;
   EFI_CREATE_EVENT_EX                           CreateEventEx;
   EFI_ALLOCATE_RING3_PAGES                      AllocateRing3Pages;
+  EFI_ALLOCATE_CORE_COPY                        AllocateCoreCopy;
 } EFI_BOOT_SERVICES;
 
 ///

MdePkg/Library/BaseLib/X64/SwitchStack.nasm

@@ -93,22 +93,27 @@ ASM_PFX(InternalEnterUserImage):
     retfq
 
 ;------------------------------------------------------------------------------
-; UINTN
+; typedef enum {
-; EFIAPI
+;   SysCallReadMemory         = 0,
-; CoreBootServices (
+;   SysCallAllocateRing3Pages = 1,
-;   IN  UINTN  FunctionAddress,
+;   SysCallAllocateCoreCopy   = 2,
-;   ...
+;   SysCallLocateProtocol     = 3,
-;   );
+;   SysCallMax
-;
+; } SYS_CALL_TYPE;
-;   (rcx) RIP of the next instruction saved by SYSCALL in SysCall().
-;   (rdx) Argument 1 of the called function.
-;   (r8)  Argument 2 of the called function.
-;   (r9)  Argument 3 of the called function.
-;   (r10) FunctionAddress.
-;   (r11) RFLAGS saved by SYSCALL in SysCall().
-;On stack Argument 4, 5, ...
 ;------------------------------------------------------------------------------
+
+%define READ_MEMORY           0
+%define ALLOCATE_RING3_PAGES  1
+%define ALLOCATE_CORE_COPY    2
+%define LOCATE_PROTOCOL       3
+
 %macro CallSysRet 0
+    ; Prepare SYSRET arguments.
+    pop     rcx
+
+    ; Switch from Core to User data segment selectors.
+    pop     r11
+
 o16 mov     ds, r11
 o16 mov     es, r11
 o16 mov     fs, r11
@@ -128,11 +133,45 @@ o64 sysret
     ; SYSRET copies the value in RCX into RIP and loads RFLAGS from R11.
 %endmacro
 
+%macro DisableSMAP 0
+    pushfq
+    pop     rcx
+    or      rcx, 0x40000 ; Set AC (bit 18)
+    push    rcx
+    popfq
+%endmacro
+
+%macro EnableSMAP 0
+    pushfq
+    pop     rcx
+    and     rcx, ~0x40000 ; Clear AC (bit 18)
+    push    rcx
+    popfq
+%endmacro
+
+;------------------------------------------------------------------------------
+; UINTN
+; EFIAPI
+; CoreBootServices (
+;   IN  UINT8  Type,
+;   IN  UINTN  FunctionAddress,
+;   ...
+;   );
+;
+;   (rcx) RIP of the next instruction saved by SYSCALL in SysCall().
+;   (rdx) FunctionAddress.
+;   (r8)  Argument 1 of the called function.
+;   (r9)  Argument 2 of the called function.
+;   (r10) Type.
+;   (r11) RFLAGS saved by SYSCALL in SysCall().
+;On stack Argument 3, 4, ...
+;------------------------------------------------------------------------------
 global ASM_PFX(CoreBootServices)
 ASM_PFX(CoreBootServices):
-    ; Save User data segment selector.
+    ; Save User data segment selector temporarily in R11.
     mov     r11, ds
 
+    ; Switch from User to Core data segment selectors.
     mov     ax, ss
     mov     ds, ax
     mov     es, ax
@@ -148,34 +187,115 @@ ASM_PFX(CoreBootServices):
     push    rbp
     mov     rbp, rsp
 
-    cmp     r10, 0
+    ; Save User data segment selector on Core SysCall Stack.
-    je      readMemory
+    push    r11
+
+    ; Save FunctionAddress in R11 as it will be called later.
+    mov     r11, rdx
 
     ; Save return address for SYSRET.
     push    rcx
 
-    ; Replace argument according to UEFI calling convention.
+    cmp     r10, READ_MEMORY
-    mov     rcx, rdx
+    je      readMemory
-    mov     rdx, r8
-    mov     r8, r9
-    ; mov     r9, [rax + 8*3]
-    ; mov   r11, [rax + 8*4]
-    ; push  r11
-    ; ...
 
-    ; Call Boot Service by FunctionAddress.
+    cmp     r10, ALLOCATE_RING3_PAGES
-    call    [r10]
+    je      allocateRing3Pages
 
-    ; Prepare SYSRET arguments.
+    cmp     r10, ALLOCATE_CORE_COPY
-    pop     rcx
+    je      allocateCoreCopy
 
-    CallSysRet
+    cmp     r10, LOCATE_PROTOCOL
+    je      locateProtocol
 
+;------------------------------------------------------------------------------
+; UINTN
+; ReadMemory (
+;   IN UINTN Address
+;   );
 readMemory:
     mov    rax, [rdx]
 
     CallSysRet
 
+;------------------------------------------------------------------------------
+; EFI_STATUS
+; AllocateRing3Pages (
+;   IN UINTN     NumberOfPages,
+;   IN OUT VOID  **Memory
+;   );
+allocateRing3Pages:
+    ; Save User (VOID **)Memory on Core SysCall Stack.
+    push    r9
+
+    ; Replace argument according to UEFI calling convention.
+    mov     rcx, r8
+    ; Allocate space for (VOID *)Memory on Core SysCall Stack.
+    sub     rsp, 8
+    mov     rdx, rsp
+
+    ; Call Boot Service by FunctionAddress.
+    call    [r11]
+
+    DisableSMAP
+
+    ; Copy (VOID *)Memory from Core SysCall Stack to User Stack.
+    pop     rdx
+    pop     r9
+    mov     [r9], rdx
+
+    EnableSMAP
+
+    CallSysRet
+
+;------------------------------------------------------------------------------
+; VOID *
+; AllocateCoreCopy (
+;   IN UINTN       AllocationSize,
+;   IN CONST VOID  *Buffer
+;   );
+allocateCoreCopy:
+    DisableSMAP
+
+    ; Replace argument according to UEFI calling convention.
+    mov     rcx, r8
+    mov     rdx, r9
+
+    ; Call Boot Service by FunctionAddress.
+    call    [r11]
+
+    EnableSMAP
+
+    CallSysRet
+
+;------------------------------------------------------------------------------
+; EFI_STATUS
+; LocateProtocol (
+;   IN  EFI_GUID  *Protocol,
+;   IN  VOID      *Registration  OPTIONAL,
+;   OUT VOID      **Interface
+;   );
+locateProtocol:
+    ; Replace argument according to UEFI calling convention.
+    mov     rcx, r8
+    mov     rdx, r9
+    ; Allocate space for (VOID *)Interface on Core SysCall Stack.
+    sub     rsp, 8
+    mov     r8, rsp
+
+    ; Call Boot Service by FunctionAddress.
+    call    [r11]
+
+    DisableSMAP
+
+    ; Copy (VOID *)Interface from Core SysCall Stack to User Stack.
+    pop     rcx
+    mov     rdx, [rbp + 8]   ; rdx = User rsp
+    mov     [rdx + 8*4], rcx ; 5th argument of SysCall (SysCallLocateProtocol)
+
+    EnableSMAP
+
+    CallSysRet
 
 SECTION .data
 

MdePkg/Library/Ring3UefiBootServicesTableLib/Ring3.h

@@ -5,14 +5,22 @@
 
 **/
 
+typedef enum {
+  SysCallReadMemory         = 0,
+  SysCallAllocateRing3Pages = 1,
+  SysCallAllocateCoreCopy   = 2,
+  SysCallLocateProtocol     = 3,
+  SysCallMax
+} SYS_CALL_TYPE;
+
 UINTN
 EFIAPI
 SysCall (
+  IN  UINT8  Type,
   IN  UINTN  FunctionAddress,
   ...
   );
 
-
 /**
   Raise the task priority level to the new level.
   High level is implemented by disabling processor interrupts.

MdePkg/Library/Ring3UefiBootServicesTableLib/Ring3UefiBootServicesTableLib.c

@@ -94,7 +94,7 @@ UefiBootServicesTableLibConstructor (
   // Cache pointer to the EFI Boot Services Table
   //
   mCoreBS = (EFI_BOOT_SERVICES *)SysCall (
-                                   0,
+                                   SysCallReadMemory,
                                    (UINTN)SystemTable + OFFSET_OF (EFI_SYSTEM_TABLE, BootServices)
                                    );
   ASSERT (mCoreBS != NULL);
@@ -504,16 +504,31 @@ EFI_STATUS
 EFIAPI
 Ring3LocateProtocol (
   IN  EFI_GUID  *Protocol,
-  IN  VOID      *Registration OPTIONAL,
+  IN  VOID      *CoreRegistration OPTIONAL,
   OUT VOID      **Interface
   )
 {
-  EFI_STATUS Status;
+  EFI_STATUS  Status;
+  EFI_GUID    *CoreProtocol;
+
+  EFI_DEVICE_PATH_UTILITIES_PROTOCOL *UserProtocol;
+
+  CoreProtocol = (VOID *)SysCall (
+                           SysCallAllocateCoreCopy,
+                           (UINTN)mCoreBS + OFFSET_OF (EFI_BOOT_SERVICES, AllocateCoreCopy),
+                           sizeof (EFI_GUID),
+                           Protocol
+                           );
+  if (CoreProtocol == NULL) {
+    DEBUG ((DEBUG_ERROR, "Ring3: Failed to allocate core copy of the Protocol variable.\n"));
+    return EFI_OUT_OF_RESOURCES;
+  }
 
   Status = (EFI_STATUS)SysCall (
+                         SysCallLocateProtocol,
                          (UINTN)mCoreBS + OFFSET_OF (EFI_BOOT_SERVICES, LocateProtocol),
-                         Protocol,
+                         CoreProtocol,
-                         Registration,
+                         CoreRegistration,
                          Interface
                          );
   if (EFI_ERROR (Status)) {
@@ -522,11 +537,10 @@ Ring3LocateProtocol (
   }
 
   if (CompareGuid (Protocol, &gEfiDevicePathUtilitiesProtocolGuid)) {
-    EFI_DEVICE_PATH_UTILITIES_PROTOCOL *UserProtocol;
-
     mCoreDevicePathUtilitiesProtocol = (EFI_DEVICE_PATH_UTILITIES_PROTOCOL *)*Interface;
 
     Status = (EFI_STATUS)SysCall (
+                           SysCallAllocateRing3Pages,
                            (UINTN)mCoreBS + OFFSET_OF (EFI_BOOT_SERVICES, AllocateRing3Pages),
                            EFI_SIZE_TO_PAGES (sizeof (EFI_DEVICE_PATH_UTILITIES_PROTOCOL)),
                            (VOID **)&UserProtocol

MdePkg/Library/Ring3UefiBootServicesTableLib/X64/SysCall.nasm

@@ -10,13 +10,14 @@
 ; UINTN
 ; EFIAPI
 ; SysCall (
+;   IN  UINT8  Type,
 ;   IN  UINTN  FunctionAddress,
 ;   ...
 ;   );
 ;------------------------------------------------------------------------------
 global ASM_PFX(SysCall)
 ASM_PFX(SysCall):
-  ; Save FunctionAddress for CoreBootServices().
+  ; Save Type for CoreBootServices().
   mov     r10, rcx
 
   ; SYSCALL saves RFLAGS into R11 and the RIP of the next instruction into RCX.