From f0053e837a2141e3c09ad376efe27fd17c522b04 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Fri, 2 Feb 2018 02:10:05 +0100 Subject: [PATCH] UefiCpuPkg/PiSmmCpuDxeSmm: patch "gSmmCr0" with PatchInstructionX86() Like "gSmmCr4" in the previous patch, "gSmmCr0" is not only used for machine code patching, but also as a means to communicate the initial CR0 value from SmmRelocateBases() to InitSmmS3ResumeState(). In other words, the last four bytes of the "mov eax, Cr0Value" instruction's binary representation are utilized as normal data too. In order to get rid of the DB for "mov eax, Cr0Value", we have to split both roles, patching and data flow. Introduce the "mSmmCr0" global (SMRAM) variable for the data flow purpose. Rename the "gSmmCr0" variable to "gPatchSmmCr0" so that its association with PatchInstructionX86() is clear from the declaration, change its type to X86_ASSEMBLY_PATCH_LABEL, and patch it with PatchInstructionX86(), to the value now contained in "mSmmCr0". This lets us remove the binary (DB) encoding of "mov eax, Cr0Value" in "SmmInit.nasm". Cc: Eric Dong Cc: Michael D Kinney Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=866 Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Laszlo Ersek Reviewed-by: Liming Gao --- UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c | 2 +- UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm | 6 +++--- UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 4 +++- UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h | 3 ++- UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm | 6 +++--- 5 files changed, 12 insertions(+), 9 deletions(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c index b4ed0a56a8..0b8ef70359 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c @@ -744,7 +744,7 @@ InitSmmS3ResumeState ( SmmS3ResumeState->SmmS3StackSize = 0; } - SmmS3ResumeState->SmmS3Cr0 = gSmmCr0; + SmmS3ResumeState->SmmS3Cr0 = mSmmCr0; SmmS3ResumeState->SmmS3Cr3 = Cr3; SmmS3ResumeState->SmmS3Cr4 = mSmmCr4; diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm index bd07a6e4f5..0f62fe4487 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm @@ -24,7 +24,7 @@ extern ASM_PFX(mSmmRelocationOriginalAddress) global ASM_PFX(gPatchSmmCr3) global ASM_PFX(gPatchSmmCr4) -global ASM_PFX(gSmmCr0) +global ASM_PFX(gPatchSmmCr0) global ASM_PFX(gSmmJmpAddr) global ASM_PFX(gSmmInitStack) global ASM_PFX(gcSmiInitGdtr) @@ -60,8 +60,8 @@ ASM_PFX(gPatchSmmCr4): rdmsr or eax, ebx ; set NXE bit if NX is available wrmsr - DB 0x66, 0xb8 ; mov eax, imm32 -ASM_PFX(gSmmCr0): DD 0 + mov eax, strict dword 0 ; source operand will be patched +ASM_PFX(gPatchSmmCr0): mov di, PROTECT_MODE_DS mov cr0, eax DB 0x66, 0xea ; jmp far [ptr48] diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c index a3fd796dba..f602d86d51 100755 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c @@ -128,6 +128,7 @@ UINT8 mPhysicalAddressBits; // // Control register contents saved for SMM S3 resume state initialization. // +UINT32 mSmmCr0; UINT32 mSmmCr4; /** @@ -410,7 +411,8 @@ SmmRelocateBases ( // // Patch ASM code template with current CR0, CR3, and CR4 values // - gSmmCr0 = (UINT32)AsmReadCr0 (); + mSmmCr0 = (UINT32)AsmReadCr0 (); + PatchInstructionX86 (gPatchSmmCr0, mSmmCr0, 4); PatchInstructionX86 (gPatchSmmCr3, AsmReadCr3 (), 4); mSmmCr4 = (UINT32)AsmReadCr4 (); PatchInstructionX86 (gPatchSmmCr4, mSmmCr4, 4); diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h index 8202ce6f86..8344e0653a 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h @@ -308,7 +308,8 @@ extern IA32_FAR_ADDRESS gSmmJmpAddr; extern CONST UINT8 gcSmmInitTemplate[]; extern CONST UINT16 gcSmmInitSize; -extern UINT32 gSmmCr0; +X86_ASSEMBLY_PATCH_LABEL gPatchSmmCr0; +extern UINT32 mSmmCr0; X86_ASSEMBLY_PATCH_LABEL gPatchSmmCr3; extern UINT32 mSmmCr4; X86_ASSEMBLY_PATCH_LABEL gPatchSmmCr4; diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm index 971bd11813..1a0667bd97 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmmInit.nasm @@ -24,7 +24,7 @@ extern ASM_PFX(mSmmRelocationOriginalAddress) global ASM_PFX(gPatchSmmCr3) global ASM_PFX(gPatchSmmCr4) -global ASM_PFX(gSmmCr0) +global ASM_PFX(gPatchSmmCr0) global ASM_PFX(gSmmJmpAddr) global ASM_PFX(gSmmInitStack) global ASM_PFX(gcSmiInitGdtr) @@ -63,8 +63,8 @@ ASM_PFX(gPatchSmmCr4): or ah, BIT3 ; set NXE bit .1: wrmsr - DB 0x66, 0xb8 ; mov eax, imm32 -ASM_PFX(gSmmCr0): DD 0 + mov eax, strict dword 0 ; source operand will be patched +ASM_PFX(gPatchSmmCr0): mov cr0, eax ; enable protected mode & paging DB 0x66, 0xea ; far jmp to long mode ASM_PFX(gSmmJmpAddr): DQ 0;@LongMode -- 2.39.2