diff options
Diffstat (limited to 'UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c')
| -rw-r--r-- | UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 144 |
1 files changed, 142 insertions, 2 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c index 5f13446015..4baba1e9f8 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c @@ -113,6 +113,19 @@ InitializeSmmIdt ( EFI_STATUS Status;
BOOLEAN InterruptState;
IA32_DESCRIPTOR DxeIdtr;
+
+ //
+ // There are 32 (not 255) entries in it since only processor
+ // generated exceptions will be handled.
+ //
+ gcSmiIdtr.Limit = (sizeof(IA32_IDT_GATE_DESCRIPTOR) * 32) - 1;
+ //
+ // Allocate page aligned IDT, because it might be set as read only.
+ //
+ gcSmiIdtr.Base = (UINTN)AllocateCodePages (EFI_SIZE_TO_PAGES(gcSmiIdtr.Limit + 1));
+ ASSERT (gcSmiIdtr.Base != 0);
+ ZeroMem ((VOID *)gcSmiIdtr.Base, gcSmiIdtr.Limit + 1);
+
//
// Disable Interrupt and save DXE IDT table
//
@@ -731,9 +744,9 @@ PiCpuSmmEntry ( //
BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize * (mMaxNumberOfCpus - 1));
if ((FamilyId == 4) || (FamilyId == 5)) {
- Buffer = AllocateAlignedPages (BufferPages, SIZE_32KB);
+ Buffer = AllocateAlignedCodePages (BufferPages, SIZE_32KB);
} else {
- Buffer = AllocateAlignedPages (BufferPages, SIZE_4KB);
+ Buffer = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
}
ASSERT (Buffer != NULL);
DEBUG ((EFI_D_INFO, "SMRAM SaveState Buffer (0x%08x, 0x%08x)\n", Buffer, EFI_PAGES_TO_SIZE(BufferPages)));
@@ -842,6 +855,8 @@ PiCpuSmmEntry ( //
SmmCpuFeaturesSmmRelocationComplete ();
+ DEBUG ((DEBUG_INFO, "mXdSupported - 0x%x\n", mXdSupported));
+
//
// SMM Time initialization
//
@@ -1138,6 +1153,17 @@ ConfigSmmCodeAccessCheck ( }
/**
+ Set code region to be read only and data region to be execute disable.
+**/
+VOID
+SetRegionAttributes (
+ VOID
+ )
+{
+ SetMemMapAttributes ();
+}
+
+/**
This API provides a way to allocate memory for page table.
This API can be called more once to allocate memory for page tables.
@@ -1167,6 +1193,109 @@ AllocatePageTableMemory ( }
/**
+ Allocate pages for code.
+
+ @param[in] Pages Number of pages to be allocated.
+
+ @return Allocated memory.
+**/
+VOID *
+AllocateCodePages (
+ IN UINTN Pages
+ )
+{
+ EFI_STATUS Status;
+ EFI_PHYSICAL_ADDRESS Memory;
+
+ if (Pages == 0) {
+ return NULL;
+ }
+
+ Status = gSmst->SmmAllocatePages (AllocateAnyPages, EfiRuntimeServicesCode, Pages, &Memory);
+ if (EFI_ERROR (Status)) {
+ return NULL;
+ }
+ return (VOID *) (UINTN) Memory;
+}
+
+/**
+ Allocate aligned pages for code.
+
+ @param[in] Pages Number of pages to be allocated.
+ @param[in] Alignment The requested alignment of the allocation.
+ Must be a power of two.
+ If Alignment is zero, then byte alignment is used.
+
+ @return Allocated memory.
+**/
+VOID *
+AllocateAlignedCodePages (
+ IN UINTN Pages,
+ IN UINTN Alignment
+ )
+{
+ EFI_STATUS Status;
+ EFI_PHYSICAL_ADDRESS Memory;
+ UINTN AlignedMemory;
+ UINTN AlignmentMask;
+ UINTN UnalignedPages;
+ UINTN RealPages;
+
+ //
+ // Alignment must be a power of two or zero.
+ //
+ ASSERT ((Alignment & (Alignment - 1)) == 0);
+
+ if (Pages == 0) {
+ return NULL;
+ }
+ if (Alignment > EFI_PAGE_SIZE) {
+ //
+ // Calculate the total number of pages since alignment is larger than page size.
+ //
+ AlignmentMask = Alignment - 1;
+ RealPages = Pages + EFI_SIZE_TO_PAGES (Alignment);
+ //
+ // Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not overflow.
+ //
+ ASSERT (RealPages > Pages);
+
+ Status = gSmst->SmmAllocatePages (AllocateAnyPages, EfiRuntimeServicesCode, RealPages, &Memory);
+ if (EFI_ERROR (Status)) {
+ return NULL;
+ }
+ AlignedMemory = ((UINTN) Memory + AlignmentMask) & ~AlignmentMask;
+ UnalignedPages = EFI_SIZE_TO_PAGES (AlignedMemory - (UINTN) Memory);
+ if (UnalignedPages > 0) {
+ //
+ // Free first unaligned page(s).
+ //
+ Status = gSmst->SmmFreePages (Memory, UnalignedPages);
+ ASSERT_EFI_ERROR (Status);
+ }
+ Memory = (EFI_PHYSICAL_ADDRESS) (AlignedMemory + EFI_PAGES_TO_SIZE (Pages));
+ UnalignedPages = RealPages - Pages - UnalignedPages;
+ if (UnalignedPages > 0) {
+ //
+ // Free last unaligned page(s).
+ //
+ Status = gSmst->SmmFreePages (Memory, UnalignedPages);
+ ASSERT_EFI_ERROR (Status);
+ }
+ } else {
+ //
+ // Do not over-allocate pages in this case.
+ //
+ Status = gSmst->SmmAllocatePages (AllocateAnyPages, EfiRuntimeServicesCode, Pages, &Memory);
+ if (EFI_ERROR (Status)) {
+ return NULL;
+ }
+ AlignedMemory = (UINTN) Memory;
+ }
+ return (VOID *) AlignedMemory;
+}
+
+/**
Perform the remaining tasks.
**/
@@ -1186,6 +1315,17 @@ PerformRemainingTasks ( // Create a mix of 2MB and 4KB page table. Update some memory ranges absent and execute-disable.
//
InitPaging ();
+
+ //
+ // Mark critical region to be read-only in page table
+ //
+ SetRegionAttributes ();
+
+ //
+ // Set page table itself to be read-only
+ //
+ SetPageTableAttributes ();
+
//
// Configure SMM Code Access Check feature if available.
//
|