Rename the variable to "gPatchSmbase" so that its association with
PatchInstructionX86() is clear from the declaration, change its type to
X86_ASSEMBLY_PATCH_LABEL, and patch it with PatchInstructionX86(). This
lets us remove the binary (DB) encoding of some instructions in
"SmiEntry.nasm".
Cc: Eric Dong <eric.dong@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=866
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
Notes:
v2:
- use the X86_ASSEMBLY_PATCH_LABEL type rather than UINT8 [Mike]
UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm | 6 +++---
UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm | 6 +++---
UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c | 12 ++++++------
3 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
index a8324a7f4a84..e6e29128e64e 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
@@ -46,7 +46,7 @@ global ASM_PFX(gcSmiHandlerTemplate)
global ASM_PFX(gcSmiHandlerSize)
global ASM_PFX(gSmiCr3)
global ASM_PFX(gSmiStack)
-global ASM_PFX(gSmbase)
+global ASM_PFX(gPatchSmbase)
global ASM_PFX(mXdSupported)
extern ASM_PFX(gSmiHandlerIdtr)
@@ -65,8 +65,8 @@ _SmiEntryPoint:
o32 lgdt [cs:bx] ; lgdt fword ptr cs:[bx]
mov ax, PROTECT_MODE_CS
mov [cs:bx-0x2],ax
- DB 0x66, 0xbf ; mov edi, SMBASE
-ASM_PFX(gSmbase): DD 0
+ mov edi, strict dword 0 ; source operand will be patched
+ASM_PFX(gPatchSmbase):
lea eax, [edi + (@32bit - _SmiEntryPoint) + 0x8000]
mov [cs:bx-0x6],eax
mov ebx, cr0
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
index 697fd2bec7c6..0e314279a541 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
@@ -53,7 +53,7 @@ extern ASM_PFX(gSmiHandlerIdtr)
extern ASM_PFX(CpuSmmDebugEntry)
extern ASM_PFX(CpuSmmDebugExit)
-global ASM_PFX(gSmbase)
+global ASM_PFX(gPatchSmbase)
global ASM_PFX(mXdSupported)
global ASM_PFX(gSmiStack)
global ASM_PFX(gSmiCr3)
@@ -75,8 +75,8 @@ _SmiEntryPoint:
o32 lgdt [cs:bx] ; lgdt fword ptr cs:[bx]
mov ax, PROTECT_MODE_CS
mov [cs:bx-0x2],ax
- DB 0x66, 0xbf ; mov edi, SMBASE
-ASM_PFX(gSmbase): DD 0
+ mov edi, strict dword 0 ; source operand will be patched
+ASM_PFX(gPatchSmbase):
lea eax, [edi + (@ProtectedMode - _SmiEntryPoint) + 0x8000]
mov [cs:bx-0x6],eax
mov ebx, cr0
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
index 3188d438181c..d34345d5ff80 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
@@ -105,11 +105,11 @@ typedef struct {
///
/// Variables from SMI Handler
///
-extern UINT32 gSmbase;
-extern volatile UINT32 gSmiStack;
-extern UINT32 gSmiCr3;
-extern volatile UINT8 gcSmiHandlerTemplate[];
-extern CONST UINT16 gcSmiHandlerSize;
+X86_ASSEMBLY_PATCH_LABEL gPatchSmbase;
+extern volatile UINT32 gSmiStack;
+extern UINT32 gSmiCr3;
+extern volatile UINT8 gcSmiHandlerTemplate[];
+extern CONST UINT16 gcSmiHandlerSize;
//
// Variables used by SMI Handler
@@ -718,7 +718,7 @@ InstallSmiHandler (
//
gSmiStack = (UINT32)((UINTN)SmiStack + StackSize - sizeof (UINTN));
gSmiCr3 = Cr3;
- gSmbase = SmBase;
+ PatchInstructionX86 (gPatchSmbase, SmBase, 4);
gSmiHandlerIdtr.Base = IdtBase;
gSmiHandlerIdtr.Limit = (UINT16)(IdtSize - 1);
--
2.14.1.3.gb7cf6e02401b
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel