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authorSheng Wei <w.sheng@intel.com>2023-11-09 17:14:39 +0800
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2023-12-07 09:43:43 +0000
commit553dfb0f57ae8a666938873cf836a33549568c87 (patch)
treedf38e7205912795b895e2e462bfdd4e2afc22b95 /UefiCpuPkg
parentfd1dd8568c78c594540990eaa4fbe37fdd3b1839 (diff)
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edk2-553dfb0f57ae8a666938873cf836a33549568c87.tar.bz2
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UefiCpuPkg: Backup and Restore MSR IA32_U_CET in SMI handler.
OS may enable CET-IBT feature by set MSR IA32_U_CET.bit2. If IA32_U_CET.bit2 is set, CPU is in WAIT_FOR_ENDBRANCH state and the next assemble code is not ENDBR, it will trigger #CP exception when set CR4.CET bit. SMI handler needs to backup MSR IA32_U_CET and clear MSR IA32_U_CET before set CR4.CET bit, And SMI handler needs to restore MSR IA32_U_CET when exit SMI handler. Signed-off-by: Sheng Wei <w.sheng@intel.com> Cc: Eric Dong <eric.dong@intel.com> Cc: Ray Ni <ray.ni@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Wu Jiaxin <jiaxin.wu@intel.com> Cc: Tan Dun <dun.tan@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com>
Diffstat (limited to 'UefiCpuPkg')
-rw-r--r--UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm15
-rw-r--r--UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm15
2 files changed, 30 insertions, 0 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
index 87a31b71a9..d84e81505e 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
@@ -202,11 +202,21 @@ ASM_PFX(mPatchCetSupported):
push edx
push eax
+ mov ecx, MSR_IA32_U_CET
+ rdmsr
+ push edx
+ push eax
+
mov ecx, MSR_IA32_PL0_SSP
rdmsr
push edx
push eax
+ mov ecx, MSR_IA32_U_CET
+ xor eax, eax
+ xor edx, edx
+ wrmsr
+
mov ecx, MSR_IA32_S_CET
mov eax, MSR_IA32_CET_SH_STK_EN
xor edx, edx
@@ -276,6 +286,11 @@ CetDone:
pop edx
wrmsr
+ mov ecx, MSR_IA32_U_CET
+ pop eax
+ pop edx
+ wrmsr
+
mov ecx, MSR_IA32_S_CET
pop eax
pop edx
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
index e7c51e6950..644366ba19 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/SmiEntry.nasm
@@ -217,6 +217,11 @@ ASM_PFX(mPatchCetSupported):
push rdx
push rax
+ mov ecx, MSR_IA32_U_CET
+ rdmsr
+ push rdx
+ push rax
+
mov ecx, MSR_IA32_PL0_SSP
rdmsr
push rdx
@@ -227,6 +232,11 @@ ASM_PFX(mPatchCetSupported):
push rdx
push rax
+ mov ecx, MSR_IA32_U_CET
+ xor eax, eax
+ xor edx, edx
+ wrmsr
+
mov ecx, MSR_IA32_S_CET
mov eax, MSR_IA32_CET_SH_STK_EN
xor edx, edx
@@ -325,6 +335,11 @@ mCetSupportedAbsAddr:
pop rdx
wrmsr
+ mov ecx, MSR_IA32_U_CET
+ pop rax
+ pop rdx
+ wrmsr
+
mov ecx, MSR_IA32_S_CET
pop rax
pop rdx