passive only - videoprt

Author: DarkFire01

win32ss/drivers/videoprt/resource.c

@@ -1009,15 +1009,25 @@ VideoPortVerifyAccessRanges(
         /* If releasing VGA device resources, clear tracked ranges */
         if (DeviceExtension->IsVgaDriver)
         {
-            KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
-            if (VgaRanges)
+            /* Mutexes can only be acquired at PASSIVE_LEVEL */
+            if (KeGetCurrentIrql() == PASSIVE_LEVEL)
             {
-                ExFreePoolWithTag(VgaRanges, TAG_VIDEO_PORT);
-                VgaRanges = NULL;
+                KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
+                if (VgaRanges)
+                {
+                    ExFreePoolWithTag(VgaRanges, TAG_VIDEO_PORT);
+                    VgaRanges = NULL;
+                }
+                NumOfVgaRanges = 0;
+                VgaDeviceExtension = NULL;
+                KeReleaseMutex(&VgaSyncLock, FALSE);
+            }
+            else
+            {
+                /* Can't acquire mutex at elevated IRQL; skip VGA tracking cleanup */
+                WARN_(VIDEOPRT, "VideoPortVerifyAccessRanges: Cannot release VGA resources at IRQL %d\n",
+                      KeGetCurrentIrql());
             }
-            NumOfVgaRanges = 0;
-            VgaDeviceExtension = NULL;
-            KeReleaseMutex(&VgaSyncLock, FALSE);
         }
         return NO_ERROR;
     }
@@ -1188,25 +1198,28 @@ VideoPortVerifyAccessRanges(
         /* Track VGA access ranges on success for fallback handling */
         if (DeviceExtension->IsVgaDriver)
         {
-            KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
-            if (VgaRanges)
+            if (KeGetCurrentIrql() == PASSIVE_LEVEL)
             {
-                ExFreePoolWithTag(VgaRanges, TAG_VIDEO_PORT);
-                VgaRanges = NULL;
-                NumOfVgaRanges = 0;
-            }
-            if (NumAccessRanges)
-            {
-                SIZE_T sz = NumAccessRanges * sizeof(VIDEO_ACCESS_RANGE);
-                VgaRanges = ExAllocatePoolWithTag(PagedPool, sz, TAG_VIDEO_PORT);
+                KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
                 if (VgaRanges)
                 {
-                    RtlCopyMemory(VgaRanges, AccessRanges, sz);
-                    NumOfVgaRanges = NumAccessRanges;
-                    VgaDeviceExtension = DeviceExtension;
+                    ExFreePoolWithTag(VgaRanges, TAG_VIDEO_PORT);
+                    VgaRanges = NULL;
+                    NumOfVgaRanges = 0;
+                }
+                if (NumAccessRanges)
+                {
+                    SIZE_T sz = NumAccessRanges * sizeof(VIDEO_ACCESS_RANGE);
+                    VgaRanges = ExAllocatePoolWithTag(PagedPool, sz, TAG_VIDEO_PORT);
+                    if (VgaRanges)
+                    {
+                        RtlCopyMemory(VgaRanges, AccessRanges, sz);
+                        NumOfVgaRanges = NumAccessRanges;
+                        VgaDeviceExtension = DeviceExtension;
+                    }
                 }
+                KeReleaseMutex(&VgaSyncLock, FALSE);
             }
-            KeReleaseMutex(&VgaSyncLock, FALSE);
         }
         /* Leave VGA detect phase after first successful claim */
         DeviceExtension->IsVgaDetect = FALSE;

win32ss/drivers/videoprt/videoprt.c

@@ -566,7 +566,6 @@ IntVideoPortFindAdapter(
         /* If we released VGA resources, reclaim them so VGA fallback still works */
         if (VgaResourcesReleased)
         {
-            KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
             if (VgaDeviceExtension && VgaRanges && NumOfVgaRanges)
             {
                 INFO_(VIDEOPRT, "Reclaiming VGA resources after failed probe\n");
@@ -577,7 +576,6 @@ IntVideoPortFindAdapter(
                     WARN_(VIDEOPRT, "Failed to reclaim VGA resources after probe failure\n");
                 }
             }
-            KeReleaseMutex(&VgaSyncLock, FALSE);
         }
         Status = STATUS_UNSUCCESSFUL;
         goto Failure;
@@ -660,7 +658,6 @@ IntVideoPortFindAdapter(
     }
 
     /* Attempt to reclaim VGA resources after probing if a VGA device exists */
-    KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
     if (VgaDeviceExtension && VgaRanges && NumOfVgaRanges)
     {
         VP_STATUS vr;
@@ -672,17 +669,21 @@ IntVideoPortFindAdapter(
         {
             /* Another driver has taken VGA resources; drop fallback state */
             WARN_(VIDEOPRT, "VGA reclaim failed (vpStatus=0x%X); releasing fallback state\n", vr);
-            ExFreePoolWithTag(VgaRanges, TAG_VIDEO_PORT);
-            VgaRanges = NULL;
-            NumOfVgaRanges = 0;
-            VgaDeviceExtension = NULL;
+            if (KeGetCurrentIrql() == PASSIVE_LEVEL)
+            {
+                KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
+                ExFreePoolWithTag(VgaRanges, TAG_VIDEO_PORT);
+                VgaRanges = NULL;
+                NumOfVgaRanges = 0;
+                VgaDeviceExtension = NULL;
+                KeReleaseMutex(&VgaSyncLock, FALSE);
+            }
         }
         else
         {
             INFO_(VIDEOPRT, "VGA reclaim succeeded\n");
         }
     }
-    KeReleaseMutex(&VgaSyncLock, FALSE);
 
     INFO_(VIDEOPRT, "STATUS_SUCCESS\n");
     return STATUS_SUCCESS;
@@ -695,7 +696,6 @@ IntVideoPortFindAdapter(
     /* Explicitly reclaim VGA resources on complete failure */
     if (VgaResourcesReleased)
     {
-        KeWaitForMutexObject(&VgaSyncLock, Executive, KernelMode, FALSE, NULL);
         if (VgaDeviceExtension && VgaRanges && NumOfVgaRanges)
         {
             INFO_(VIDEOPRT, "Final reclaim attempt of VGA resources during failure cleanup\n");
@@ -706,7 +706,6 @@ IntVideoPortFindAdapter(
                 WARN_(VIDEOPRT, "VGA reclaim failed during failure cleanup\n");
             }
         }
-        KeReleaseMutex(&VgaSyncLock, FALSE);
     }
     IoDeleteDevice(DeviceObject);
     return Status;