[NTOSKRNL] Only allow page file on a few specific device types

[reactos.git] / ntoskrnl / mm / pagefile.c

diff --git a/ntoskrnl/mm/pagefile.c b/ntoskrnl/mm/pagefile.c
index dd24fe7..0649f0f 100644 (file)
--- a/ntoskrnl/mm/pagefile.c
+++ b/ntoskrnl/mm/pagefile.c
@@ -290,10 +290,10 @@ MmFreeSwapPage(SWAPENTRY Entry)
         KeBugCheck(MEMORY_MANAGEMENT);
     }
 
-    RtlClearBit(PagingFile->AllocMap, off >> 5);
+    RtlClearBit(PagingFile->Bitmap, off >> 5);
 
-    PagingFile->FreePages++;
-    PagingFile->UsedPages--;
+    PagingFile->FreeSpace++;
+    PagingFile->CurrentUsage--;
 
     MiFreeSwapPages++;
     MiUsedSwapPages--;
@@ -320,9 +320,9 @@ MmAllocSwapPage(VOID)
     for (i = 0; i < MAX_PAGING_FILES; i++)
     {
         if (MmPagingFile[i] != NULL &&
-                MmPagingFile[i]->FreePages >= 1)
+                MmPagingFile[i]->FreeSpace >= 1)
         {
-            off = RtlFindClearBitsAndSet(MmPagingFile[i]->AllocMap, 1, 0);
+            off = RtlFindClearBitsAndSet(MmPagingFile[i]->Bitmap, 1, 0);
             if (off == 0xFFFFFFFF)
             {
                 KeBugCheck(MEMORY_MANAGEMENT);
@@ -364,6 +364,7 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     SECURITY_DESCRIPTOR SecurityDescriptor;
     PACL Dacl;
     PWSTR Buffer;
+    DEVICE_TYPE DeviceType;
 
     DPRINT("NtCreatePagingFile(FileName %wZ, MinimumSize %I64d)\n",
            FileName, MinimumSize->QuadPart);
@@ -690,6 +691,17 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     /* DACL is no longer needed, free it */
     ExFreePoolWithTag(Dacl, 'lcaD');
 
+    /* FIXME: To enable once page file managment is moved to ARM3 */
+#if 0
+    /* Check we won't overflow commit limit with the page file */
+    if (MmTotalCommitLimitMaximum + (SafeMaximumSize.QuadPart >> PAGE_SHIFT) <= MmTotalCommitLimitMaximum)
+    {
+        ZwClose(FileHandle);
+        ExFreePoolWithTag(Buffer, TAG_MM);
+        return STATUS_INVALID_PARAMETER_3;
+    }
+#endif
+
     /* Set its end of file to minimal size */
     Status = ZwSetInformationFile(FileHandle,
                                   &IoStatus,
@@ -704,7 +716,7 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     }
 
     Status = ObReferenceObjectByHandle(FileHandle,
-                                       FILE_ALL_ACCESS,
+                                       FILE_READ_DATA | FILE_WRITE_DATA,
                                        IoFileObjectType,
                                        KernelMode,
                                        (PVOID*)&FileObject,
@@ -716,6 +728,17 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
         return Status;
     }
 
+    /* Only allow page file on a few device types */
+    DeviceType = IoGetRelatedDeviceObject(FileObject)->DeviceType;
+    if (DeviceType != FILE_DEVICE_DISK_FILE_SYSTEM && DeviceType != FILE_DEVICE_NETWORK_FILE_SYSTEM &&
+        DeviceType != FILE_DEVICE_DFS_VOLUME && DeviceType != FILE_DEVICE_DFS_FILE_SYSTEM)
+    {
+        ObDereferenceObject(FileObject);
+        ZwClose(FileHandle);
+        ExFreePoolWithTag(Buffer, TAG_MM);
+        return Status;
+    }
+
     /* Deny page file creation on a floppy disk */
     FsDeviceInfo.Characteristics = 0;
     IoQueryVolumeInformation(FileObject, FileFsDeviceInformation, sizeof(FsDeviceInfo), &FsDeviceInfo, &Count);
@@ -741,17 +764,21 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     PagingFile->FileHandle = FileHandle;
     PagingFile->FileObject = FileObject;
     PagingFile->MaximumSize = (SafeMaximumSize.QuadPart >> PAGE_SHIFT);
-    PagingFile->CurrentSize = (SafeMinimumSize.QuadPart >> PAGE_SHIFT);
+    PagingFile->Size = (SafeMinimumSize.QuadPart >> PAGE_SHIFT);
     PagingFile->MinimumSize = (SafeMinimumSize.QuadPart >> PAGE_SHIFT);
-    PagingFile->FreePages = (ULONG)(SafeMinimumSize.QuadPart / PAGE_SIZE);
-    PagingFile->UsedPages = 0;
+    /* First page is never used: it's the header
+     * TODO: write it
+     */
+    PagingFile->FreeSpace = (ULONG)(SafeMinimumSize.QuadPart / PAGE_SIZE) - 1;
+    PagingFile->CurrentUsage = 0;
     PagingFile->PageFileName = PageFileName;
+    ASSERT(PagingFile->Size == PagingFile->FreeSpace + PagingFile->CurrentUsage + 1);
 
-    AllocMapSize = sizeof(RTL_BITMAP) + (((PagingFile->FreePages + 31) / 32) * sizeof(ULONG));
-    PagingFile->AllocMap = ExAllocatePoolWithTag(NonPagedPool,
-                                                 AllocMapSize,
-                                                 TAG_MM);
-    if (PagingFile->AllocMap == NULL)
+    AllocMapSize = sizeof(RTL_BITMAP) + (((PagingFile->MaximumSize + 31) / 32) * sizeof(ULONG));
+    PagingFile->Bitmap = ExAllocatePoolWithTag(NonPagedPool,
+                                               AllocMapSize,
+                                               TAG_MM);
+    if (PagingFile->Bitmap == NULL)
     {
         ExFreePoolWithTag(PagingFile, TAG_MM);
         ObDereferenceObject(FileObject);
@@ -760,10 +787,10 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
         return STATUS_INSUFFICIENT_RESOURCES;
     }
 
-    RtlInitializeBitMap(PagingFile->AllocMap,
-                        (PULONG)(PagingFile->AllocMap + 1),
-                        (ULONG)(PagingFile->FreePages));
-    RtlClearAllBits(PagingFile->AllocMap);
+    RtlInitializeBitMap(PagingFile->Bitmap,
+                        (PULONG)(PagingFile->Bitmap + 1),
+                        (ULONG)(PagingFile->MaximumSize));
+    RtlClearAllBits(PagingFile->Bitmap);
 
     /* FIXME: should be calling unsafe instead,
      * we should already be in a guarded region
@@ -772,7 +799,7 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     ASSERT(MmPagingFile[MmNumberOfPagingFiles] == NULL);
     MmPagingFile[MmNumberOfPagingFiles] = PagingFile;
     MmNumberOfPagingFiles++;
-    MiFreeSwapPages = MiFreeSwapPages + PagingFile->FreePages;
+    MiFreeSwapPages = MiFreeSwapPages + PagingFile->FreeSpace;
     KeReleaseGuardedMutex(&MmPageFileCreationLock);
 
     MmSwapSpaceMessage = FALSE;