MdePkg: Fix X64 clang compile issues.

Fixed issues with X64 clang, and also make StackSwitch push a zero on the new stack to prevent a stack unwind into memory that is no longer valid.

signed-off-by: andrewfish
reviewed-by: lgao4
reviewed-by: mdkinney



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12007 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 37 insertions, 25 deletions

diff --git a/MdePkg/Library/BaseLib/X64/SwitchStack.S b/MdePkg/Library/BaseLib/X64/SwitchStack.S
index 76c3eb5226..dc8d80e40b 100644
--- a/MdePkg/Library/BaseLib/X64/SwitchStack.S
+++ b/MdePkg/Library/BaseLib/X64/SwitchStack.S
@@ -37,7 +37,10 @@
 #------------------------------------------------------------------------------

 ASM_GLOBAL ASM_PFX(InternalSwitchStack)

 ASM_PFX(InternalSwitchStack):

-    mov     %rcx, %rax

+	  pushq   %rbp            

+  	movq    %rsp, %rbp

+    

+    mov     %rcx, %rax  // Shift registers for new call

     mov     %rdx, %rcx

     mov     %r8, %rdx

     #

@@ -45,4 +48,5 @@ ASM_PFX(InternalSwitchStack):
     # in case the callee wishes to spill them.

     #

     lea     -0x20(%r9), %rsp

-    call    *%rax

+    pushq   $0        // stop gdb stack unwind

+    jmp     *%rax     // call EntryPoint ()

diff --git a/MdePkg/Library/BaseLib/X64/Thunk16.S b/MdePkg/Library/BaseLib/X64/Thunk16.S
index 049ec86355..dabf2d09e1 100644
--- a/MdePkg/Library/BaseLib/X64/Thunk16.S
+++ b/MdePkg/Library/BaseLib/X64/Thunk16.S
@@ -49,12 +49,17 @@ ASM_GLOBAL ASM_PFX(InternalAsmThunk16)
 .set  IA32_REGS_SIZE, 56

 

     .data

-

-ASM_PFX(m16Size):         .word      ASM_PFX(InternalAsmThunk16) - ASM_PFX(m16Start)

-ASM_PFX(mThunk16Attr):    .word      _ThunkAttr - ASM_PFX(m16Start)

-ASM_PFX(m16Gdt):          .word      ASM_PFX(NullSeg) - ASM_PFX(m16Start)

-ASM_PFX(m16GdtrBase):     .word      _16GdtrBase - ASM_PFX(m16Start)

-ASM_PFX(mTransition):     .word      _EntryPoint - ASM_PFX(m16Start)

+    

+.set Lm16Size, ASM_PFX(InternalAsmThunk16) - ASM_PFX(m16Start)

+ASM_PFX(m16Size):         .word      Lm16Size

+.set  LmThunk16Attr, L_ThunkAttr - ASM_PFX(m16Start)

+ASM_PFX(mThunk16Attr):    .word      LmThunk16Attr

+.set Lm16Gdt, ASM_PFX(NullSeg) - ASM_PFX(m16Start)

+ASM_PFX(m16Gdt):          .word      Lm16Gdt

+.set Lm16GdtrBase, _16GdtrBase - ASM_PFX(m16Start)

+ASM_PFX(m16GdtrBase):     .word      Lm16GdtrBase

+.set LmTransition, _EntryPoint - ASM_PFX(m16Start)

+ASM_PFX(mTransition):     .word      LmTransition

 

     .text

 

@@ -91,7 +96,7 @@ L_Base:
     .byte 0x1e                          # push ds

     .byte 0x66,0x60                     # pushad

     .byte 0x66,0xba                     # mov edx, imm32

-_ThunkAttr:  .space  4

+L_ThunkAttr:  .space  4

     testb   $THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15, %dl

     jz      L_1

     movl    $0x15cd2401,%eax            # mov ax, 2401h & int 15h

@@ -120,7 +125,7 @@ L_2:
     .byte 0x66,0x2e,0x89,0x87           # mov cs:[bx + (L_64Eip - L_Base)], eax

     .word   L_64Eip - L_Base

     .byte 0x66,0xb8                     # mov eax, imm32

-SavedCr4:   .space  4

+L_SavedCr4:   .long  0

     movq    %rax, %cr4

     #

     # rdi in the instruction below is indeed bx in 16-bit code

@@ -133,15 +138,15 @@ SavedCr4:   .space  4
     orb     $1,%ah

     wrmsr

     .byte 0x66,0xb8                     # mov eax, imm32

-SavedCr0:    .space      4

+L_SavedCr0:    .long      

     movq    %rax, %cr0

     .byte 0x66,0xea                     # jmp far cs:L_64Bit

-L_64Eip:     .space      4

-SavedCs:     .space      2

+L_64Eip:     .long       0

+L_SavedCs:     .space      2

 L_64BitCode: 

     .byte   0x90

     .byte   0x67,0xbc                  # mov esp, imm32

-SavedSp:    .space 4                   # restore stack

+L_SavedSp:    .long                      # restore stack

     nop

     ret

 

@@ -258,19 +263,20 @@ ASM_PFX(InternalAsmThunk16):
     popq    %rcx

     rep

     movsl                               # copy RegSet

-    lea     (SavedCr4 - ASM_PFX(m16Start))(%rdx), %ecx

+    lea     (L_SavedCr4 - ASM_PFX(m16Start))(%rdx), %ecx

     movl    %edx,%eax                   # eax <- transition code address

     andl    $0xf,%edx

     shll    $12,%eax                    # segment address in high order 16 bits

-    lea     (ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start))(%rdx), %ax

+    .set LBackFromUserCodeDelta, ASM_PFX(BackFromUserCode) - ASM_PFX(m16Start) 

+    lea     (LBackFromUserCodeDelta)(%rdx), %ax

     stosl                               # [edi] <- return address of user code

     sgdt    0x60(%rsp)                  # save GDT stack in argument space

     movzwq  0x60(%rsp), %r10            # r10 <- GDT limit 

-    lea     ((ASM_PFX(InternalAsmThunk16) - SavedCr4) + 0xf)(%rcx), %r11 

+    lea     ((ASM_PFX(InternalAsmThunk16) - L_SavedCr4) + 0xf)(%rcx), %r11 

     andq    $0xfffffffffffffff0, %r11   # r11 <- 16-byte aligned shadowed GDT table in real mode buffer      

     

-    movw    %r10w, (SavedGdt - SavedCr4)(%rcx)       # save the limit of shadowed GDT table

-    movq    %r11, (SavedGdt - SavedCr4 + 0x2)(%rcx)  # save the base address of shadowed GDT table

+    movw    %r10w, (SavedGdt - L_SavedCr4)(%rcx)       # save the limit of shadowed GDT table

+    movq    %r11, (SavedGdt - L_SavedCr4 + 0x2)(%rcx)  # save the base address of shadowed GDT table

     

     movq    0x62(%rsp) ,%rsi            # rsi <- the original GDT base address

     xchg   %r10, %rcx                   # save rcx to r10 and initialize rcx to be the limit of GDT table 

@@ -283,7 +289,8 @@ ASM_PFX(InternalAsmThunk16):
        

     sidt    0x50(%rsp)

     movq    %cr0, %rax

-    movl    %eax, (SavedCr0 - SavedCr4)(%rcx)

+    .set LSavedCrDelta, L_SavedCr0 - L_SavedCr4

+    movl    %eax, (LSavedCrDelta)(%rcx)

     andl    $0x7ffffffe,%eax            # clear PE, PG bits

     movq    %cr4, %rbp

     movl    %ebp, (%rcx)                # save CR4 in SavedCr4

@@ -291,17 +298,18 @@ ASM_PFX(InternalAsmThunk16):
     movl    %r8d, %esi                  # esi <- 16-bit stack segment

     .byte      0x6a, DATA32

     popq    %rdx

-    lgdt    (_16Gdtr - SavedCr4)(%rcx)

+    lgdt    (_16Gdtr - L_SavedCr4)(%rcx)

     movl    %edx,%ss

     pushfq

     lea     -8(%rdx), %edx

     lea     L_RetFromRealMode(%rip), %r8

     pushq   %r8

     movl    %cs, %r8d

-    movw    %r8w, (SavedCs - SavedCr4)(%rcx)

-    movl    %esp, (SavedSp - SavedCr4)(%rcx)

-    .byte   0xff, 0x69                  #  jmp (_EntryPoint - SavedCr4)(%rcx)

-    .byte   _EntryPoint - SavedCr4

+    movw    %r8w, (L_SavedCs - L_SavedCr4)(%rcx)

+    movl    %esp, (L_SavedSp - L_SavedCr4)(%rcx)

+    .byte   0xff, 0x69                  #  jmp (_EntryPoint - L_SavedCr4)(%rcx)

+    .set    Ltemp1, _EntryPoint - L_SavedCr4

+    .byte   Ltemp1

 L_RetFromRealMode: 

     popfq

     lgdt    0x60(%rsp)                  # restore protected mode GDTR