diff options
| -rw-r--r-- | UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 41 |
1 files changed, 27 insertions, 14 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c index 4bb23f6920..834a756061 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c @@ -67,8 +67,10 @@ InitializePageTablePool ( IN UINTN PoolPages
)
{
- VOID *Buffer;
- BOOLEAN CetEnabled;
+ VOID *Buffer;
+ BOOLEAN CetEnabled;
+ BOOLEAN WpEnabled;
+ IA32_CR0 Cr0;
//
// Always reserve at least PAGE_TABLE_POOL_UNIT_PAGES, including one page for
@@ -106,21 +108,32 @@ InitializePageTablePool ( //
if (mIsReadOnlyPageTable) {
CetEnabled = ((AsmReadCr4 () & CR4_CET_ENABLE) != 0) ? TRUE : FALSE;
- if (CetEnabled) {
- //
- // CET must be disabled if WP is disabled.
- //
- DisableCet ();
+ Cr0.UintN = AsmReadCr0 ();
+ WpEnabled = (Cr0.Bits.WP != 0) ? TRUE : FALSE;
+ if (WpEnabled) {
+ if (CetEnabled) {
+ //
+ // CET must be disabled if WP is disabled. Disable CET before clearing CR0.WP.
+ //
+ DisableCet ();
+ }
+
+ Cr0.Bits.WP = 0;
+ AsmWriteCr0 (Cr0.UintN);
}
- AsmWriteCr0 (AsmReadCr0 () & ~CR0_WP);
SmmSetMemoryAttributes ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, EFI_PAGES_TO_SIZE (PoolPages), EFI_MEMORY_RO);
- AsmWriteCr0 (AsmReadCr0 () | CR0_WP);
- if (CetEnabled) {
- //
- // re-enable CET.
- //
- EnableCet ();
+ if (WpEnabled) {
+ Cr0.UintN = AsmReadCr0 ();
+ Cr0.Bits.WP = 1;
+ AsmWriteCr0 (Cr0.UintN);
+
+ if (CetEnabled) {
+ //
+ // re-enable CET.
+ //
+ EnableCet ();
+ }
}
}
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