--- /dev/null
+/*
+ * COPYRIGHT: See COPYING in the top level directory
+ * PROJECT: ReactOS Kernel
+ * FILE: ntoskrnl/kd/i386/kdmemsup.c
+ * PURPOSE: Kernel Debugger Safe Memory Support
+ *
+ * PROGRAMMERS: arty
+ */
+
+#include <ntoskrnl.h>
+#define NDEBUG
+#include <internal/debug.h>
+
+#define HIGH_PHYS_MASK 0x80000000
+#define PAGE_TABLE_MASK 0x3ff
+#define BIG_PAGE_SIZE (1<<22)
+#define CR4_PAGE_SIZE_BIT 0x10
+#define PDE_PRESENT_BIT 1
+#define PDE_W_BIT 2
+#define PDE_PS_BIT 0x80
+
+/* VARIABLES ***************************************************************/
+
+extern ULONG MmGlobalKernelPageDirectory[1024];
+static BOOLEAN KdpPhysAccess = FALSE;
+ULONG_PTR IdentityMapAddrHigh, IdentityMapAddrLow;
+extern PFN_TYPE NTAPI MmAllocEarlyPage();
+
+ULONGLONG
+FASTCALL
+KdpPhysRead(ULONG_PTR Addr, LONG Len)
+{
+ ULONGLONG Result = 0;
+ ULONG_PTR OldCR3 = __readcr3(), OldCR4 = __readcr4();
+
+ if (Addr & HIGH_PHYS_MASK)
+ {
+ Addr &= ~HIGH_PHYS_MASK;
+ __writecr3(IdentityMapAddrHigh);
+ }
+ else
+ __writecr3(IdentityMapAddrLow);
+
+ __writecr4(OldCR4|CR4_PAGE_SIZE_BIT); // Turn on large page translation
+ __invlpg((PVOID)Addr);
+
+ switch (Len)
+ {
+ case 8:
+ Result = *((PULONGLONG)Addr);
+ break;
+ case 4:
+ Result = *((PULONG)Addr);
+ break;
+ case 2:
+ Result = *((PUSHORT)Addr);
+ break;
+ case 1:
+ Result = *((PUCHAR)Addr);
+ break;
+ }
+ __writecr4(OldCR4); // Turn off large page translation
+ __writecr3(OldCR3);
+ __invlpg((PVOID)Addr);
+
+ return Result;
+}
+
+
+VOID
+NTAPI
+KdpPhysWrite(ULONG_PTR Addr, LONG Len, ULONGLONG Value)
+{
+ ULONG_PTR OldCR3 = __readcr3(), OldCR4 = __readcr4();
+
+ if (Addr & HIGH_PHYS_MASK)
+ {
+ Addr &= ~HIGH_PHYS_MASK;
+ __writecr3(IdentityMapAddrHigh);
+ }
+ else
+ __writecr3(IdentityMapAddrLow);
+
+ __writecr4(OldCR4|CR4_PAGE_SIZE_BIT); // Turn on large page translation
+ __invlpg((PVOID)Addr);
+
+ switch (Len)
+ {
+ case 8:
+ *((PULONGLONG)Addr) = Value;
+ break;
+ case 4:
+ *((PULONG)Addr) = Value;
+ break;
+ case 2:
+ *((PUSHORT)Addr) = Value;
+ break;
+ case 1:
+ *((PUCHAR)Addr) = Value;
+ break;
+ }
+ __writecr4(OldCR4); // Turn off large page translation
+ __writecr3(OldCR3);
+ __invlpg((PVOID)Addr);
+}
+
+BOOLEAN
+NTAPI
+KdpTranslateAddress(ULONG_PTR Addr, PULONG_PTR ResultAddr)
+{
+ ULONG_PTR CR3Value = __readcr3();
+ ULONG_PTR CR4Value = __readcr4();
+ ULONG_PTR PageDirectory = (CR3Value & ~(PAGE_SIZE-1)) +
+ ((Addr >> 22) * sizeof(ULONG));
+ ULONG_PTR PageDirectoryEntry = KdpPhysRead(PageDirectory, sizeof(ULONG));
+
+ /* Not present -> fail */
+ if (!(PageDirectoryEntry & PDE_PRESENT_BIT))
+ {
+ return FALSE;
+ }
+
+ /* Big Page? */
+ if ((PageDirectoryEntry & PDE_PS_BIT) && (CR4Value & CR4_PAGE_SIZE_BIT))
+ {
+ *ResultAddr = (PageDirectoryEntry & ~(BIG_PAGE_SIZE-1)) +
+ (Addr & (BIG_PAGE_SIZE-1));
+ return TRUE;
+ }
+ else
+ {
+ ULONG_PTR PageTableAddr =
+ (PageDirectoryEntry & ~(PAGE_SIZE-1)) +
+ ((Addr >> PAGE_SHIFT) & PAGE_TABLE_MASK) * sizeof(ULONG);
+ ULONG_PTR PageTableEntry = KdpPhysRead(PageTableAddr, sizeof(ULONG));
+ if (PageTableEntry & PDE_PRESENT_BIT)
+ {
+ *ResultAddr = (PageTableEntry & ~(PAGE_SIZE-1)) +
+ (Addr & (PAGE_SIZE-1));
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
+BOOLEAN
+NTAPI
+KdpSafeReadMemory(ULONG_PTR Addr, LONG Len, PVOID Value)
+{
+ ULONG_PTR ResultPhysAddr;
+
+ if (!KdpPhysAccess)
+ {
+ memcpy(Value, (PVOID)Addr, Len);
+ return TRUE;
+ }
+
+ memset(Value, 0, Len);
+
+ if (!KdpTranslateAddress(Addr, &ResultPhysAddr))
+ return FALSE;
+
+ switch (Len)
+ {
+ case 8:
+ *((PULONGLONG)Value) = KdpPhysRead(ResultPhysAddr, Len);
+ break;
+ case 4:
+ *((PULONG)Value) = KdpPhysRead(ResultPhysAddr, Len);
+ break;
+ case 2:
+ *((PUSHORT)Value) = KdpPhysRead(ResultPhysAddr, Len);
+ break;
+ case 1:
+ *((PUCHAR)Value) = KdpPhysRead(ResultPhysAddr, Len);
+ break;
+ }
+
+ return TRUE;
+}
+
+BOOLEAN
+NTAPI
+KdpSafeWriteMemory(ULONG_PTR Addr, LONG Len, ULONGLONG Value)
+{
+ ULONG_PTR ResultPhysAddr;
+
+ if (!KdpPhysAccess)
+ {
+ memcpy((PVOID)Addr, &Value, Len);
+ return TRUE;
+ }
+
+ if (!KdpTranslateAddress(Addr, &ResultPhysAddr))
+ return FALSE;
+
+ KdpPhysWrite(ResultPhysAddr, Len, Value);
+ return TRUE;
+}
+
+VOID
+NTAPI
+KdpEnableSafeMem()
+{
+ int i;
+ PULONG IdentityMapVirt;
+ PHYSICAL_ADDRESS IdentityMapPhys, Highest = { };
+
+ if (KdpPhysAccess)
+ return;
+
+ Highest.LowPart = (ULONG)-1;
+ /* Allocate a physical page and map it to copy the phys copy code onto */
+ IdentityMapVirt = (PULONG)MmAllocateContiguousMemory(2 * PAGE_SIZE, Highest);
+ IdentityMapPhys = MmGetPhysicalAddress(IdentityMapVirt);
+ IdentityMapAddrHigh = IdentityMapPhys.LowPart;
+
+ /* Copy the kernel space */
+ memcpy(IdentityMapVirt,
+ MmGlobalKernelPageDirectory,
+ PAGE_SIZE);
+
+ /* Set up 512 4Mb pages (high 2Gig identity mapped) */
+ for (i = 0; i < 512; i++)
+ {
+ IdentityMapVirt[i] =
+ HIGH_PHYS_MASK | (i << 22) | PDE_PS_BIT | PDE_W_BIT | PDE_PRESENT_BIT;
+ }
+
+ /* Allocate a physical page and map it to copy the phys copy code onto */
+ IdentityMapAddrLow = IdentityMapAddrHigh + PAGE_SIZE;
+ IdentityMapVirt += PAGE_SIZE / sizeof(ULONG);
+
+ /* Copy the kernel space */
+ memcpy(IdentityMapVirt,
+ MmGlobalKernelPageDirectory,
+ PAGE_SIZE);
+
+ /* Set up 512 4Mb pages (low 2Gig identity mapped) */
+ for (i = 0; i < 512; i++)
+ {
+ IdentityMapVirt[i] = (i << 22) | PDE_PS_BIT | PDE_W_BIT | PDE_PRESENT_BIT;
+ }
+
+ KdpPhysAccess = TRUE;
+}
IN PVOID Src,
IN ULONG Bytes)
{
- NTSTATUS Status = STATUS_SUCCESS;
+ BOOLEAN Result = TRUE;
- _SEH_TRY
- {
- RtlCopyMemory(Dest,
- Src,
- Bytes);
- }
- _SEH_HANDLE
- {
- Status = _SEH_GetExceptionCode();
- }
- _SEH_END;
+ switch (Bytes)
+ {
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ Result = KdpSafeReadMemory((ULONG_PTR)Src, Bytes, Dest);
+ break;
+ default:
+ {
+ ULONG_PTR Start, End, Write;
+ for (Start = (ULONG_PTR)Src,
+ End = Start + Bytes,
+ Write = (ULONG_PTR)Dest;
+ Result && (Start < End);
+ Start++, Write++)
+ if (!KdpSafeReadMemory(Start, 1, (PVOID)Write))
+ Result = FALSE;
+ break;
+ }
+ }
- return Status;
+ return Result ? STATUS_SUCCESS : STATUS_ACCESS_VIOLATION;
}
NTSTATUS
IN PVOID Src,
IN ULONG Bytes)
{
- NTSTATUS Status = STATUS_SUCCESS;
-
- _SEH_TRY
- {
- RtlCopyMemory(Dest,
- Src,
- Bytes);
- }
- _SEH_HANDLE
- {
- Status = _SEH_GetExceptionCode();
- }
- _SEH_END;
-
- return Status;
+ BOOLEAN Result;
+ ULONG_PTR Start, End, Write;
+
+ for (Start = (ULONG_PTR)Src,
+ End = Start + Bytes,
+ Write = (ULONG_PTR)Dest;
+ Result && (Start < End);
+ Start++, Write++)
+ if (!KdpSafeReadMemory(Start, 1, (PVOID)Write))
+ Result = FALSE;
+
+ return Result ? STATUS_SUCCESS : STATUS_ACCESS_VIOLATION;
}
projects / reactos.git / commitdiff