X-Git-Url: https://git.reactos.org/?p=reactos.git;a=blobdiff_plain;f=ntoskrnl%2Ffstub%2Fdisksup.c;h=c4a67c3413fb637f12ff950c277bdd4bb7978e05;hp=29c3dc9ea911ff15b5a80c45b922167d12ecd80a;hb=b726d7355f0aa394852fa8c56e59cfc9bbc4293c;hpb=63b50165b246c58f1663017ba6c01ab57ccc1e01

diff --git a/ntoskrnl/fstub/disksup.c b/ntoskrnl/fstub/disksup.c
index 29c3dc9ea91..c4a67c3413f 100644
--- a/ntoskrnl/fstub/disksup.c
+++ b/ntoskrnl/fstub/disksup.c
@@ -24,6 +24,8 @@ const WCHAR DiskMountString[] = L"\\DosDevices\\%C:";
 
 #define PARTITION_MAGIC    0xaa55
 
+#define EFI_PMBR_OSTYPE_EFI 0xEE
+
 #include <pshpack1.h>
 
 typedef struct _REG_DISK_MOUNT_INFO
@@ -62,17 +64,20 @@ HalpAssignDrive(IN PUNICODE_STRING PartitionName,
     if ((DriveNumber != AUTO_DRIVE) && (DriveNumber < 26))
     {
         /* Force assignment */
+        KeAcquireGuardedMutex(&ObpDeviceMapLock);
         if ((ObSystemDeviceMap->DriveMap & (1 << DriveNumber)) != 0)
         {
             DbgPrint("Drive letter already used!\n");
+            KeReleaseGuardedMutex(&ObpDeviceMapLock);
             return FALSE;
         }
+        KeReleaseGuardedMutex(&ObpDeviceMapLock);
     }
     else
     {
         /* Automatic assignment */
         DriveNumber = AUTO_DRIVE;
-
+        KeAcquireGuardedMutex(&ObpDeviceMapLock);
         for (i = 2; i < 26; i++)
         {
             if ((ObSystemDeviceMap->DriveMap & (1 << i)) == 0)
@@ -81,6 +86,7 @@ HalpAssignDrive(IN PUNICODE_STRING PartitionName,
                 break;
             }
         }
+        KeReleaseGuardedMutex(&ObpDeviceMapLock);
 
         if (DriveNumber == AUTO_DRIVE)
         {
@@ -91,10 +97,6 @@ HalpAssignDrive(IN PUNICODE_STRING PartitionName,
 
     DPRINT("DriveNumber %d\n", DriveNumber);
 
-    /* Update the System Device Map */
-    ObSystemDeviceMap->DriveMap |= (1 << DriveNumber);
-    ObSystemDeviceMap->DriveType[DriveNumber] = DriveType;
-
     /* Build drive name */
     swprintf(DriveNameBuffer,
         L"\\??\\%C:",
@@ -1358,6 +1360,24 @@ xHalExamineMBR(IN PDEVICE_OBJECT DeviceObject,
     }
 }
 
+VOID
+NTAPI
+FstubFixupEfiPartition(IN PPARTITION_DESCRIPTOR PartitionDescriptor,
+                       IN ULONGLONG MaxOffset)
+{
+    ULONG PartitionLength;
+    PAGED_CODE();
+
+    /* Compute partition length (according to MBR entry) */
+    PartitionLength = PartitionDescriptor->StartingSectorLsb0 + PartitionDescriptor->PartitionLengthLsb0;
+    /* In case the partition length goes beyond disk size... */
+    if (PartitionLength > MaxOffset)
+    {
+        /* Resize partition to its maximum real length */
+        PartitionDescriptor->PartitionLengthLsb0 = MaxOffset - PartitionDescriptor->StartingSectorLsb0;
+    }
+}
+
 NTSTATUS
 FASTCALL
 xHalIoReadPartitionTable(IN PDEVICE_OBJECT DeviceObject,
@@ -1425,7 +1445,7 @@ xHalIoReadPartitionTable(IN PDEVICE_OBJECT DeviceObject,
             MaxOffset, MaxSector);
 
     /* Allocate our buffer */
-    Buffer = ExAllocatePoolWithTag(NonPagedPool, PAGE_SIZE, TAG_FILE_SYSTEM);
+    Buffer = ExAllocatePoolWithTag(NonPagedPool, InputSize, TAG_FILE_SYSTEM);
     if (!Buffer)
     {
         /* Fail, free the input buffer */
@@ -1503,9 +1523,6 @@ xHalIoReadPartitionTable(IN PDEVICE_OBJECT DeviceObject,
         PartitionDescriptor = (PPARTITION_DESCRIPTOR)
                                &(((PUSHORT)Buffer)[PARTITION_TABLE_OFFSET]);
 
-        /* Get the partition type */
-        PartitionType = PartitionDescriptor->PartitionType;
-
         /* Start looping partitions */
         j++;
         DPRINT("FSTUB: Partition Table %d:\n", j);
@@ -1524,6 +1541,14 @@ xHalIoReadPartitionTable(IN PDEVICE_OBJECT DeviceObject,
                     GET_STARTING_SECTOR(PartitionDescriptor),
                     GET_PARTITION_LENGTH(PartitionDescriptor));
 
+            /* Check whether we're facing a protective MBR */
+            if (PartitionType == EFI_PMBR_OSTYPE_EFI)
+            {
+                /* Partition length might be bigger than disk size */
+                FstubFixupEfiPartition(PartitionDescriptor,
+                                       MaxOffset);
+            }
+
             /* Make sure that the partition is valid, unless it's the first */
             if (!(HalpIsValidPartitionEntry(PartitionDescriptor,
                                             MaxOffset,
@@ -1686,7 +1711,7 @@ xHalIoReadPartitionTable(IN PDEVICE_OBJECT DeviceObject,
         for (Entry = 1; Entry <= 4; Entry++, PartitionDescriptor++)
         {
             /* Check if this is a container partition, since we skipped them */
-            if (IsContainerPartition(PartitionType))
+            if (IsContainerPartition(PartitionDescriptor->PartitionType))
             {
                 /* Get its offset */
                 Offset.QuadPart = VolumeOffset.QuadPart +