Changeset 82812 in vbox for trunk/src/VBox

Timestamp:

Jan 21, 2020 11:49:05 AM (5 years ago)

Author:

vboxsync

Message:

DevVGA: Don't take the device lock in vgaR3PciIORegionVRamMapUnmap as it is (or will create later) a lock order violation with the PDM lock. This is probably a regression from bugref:9218.

File:

• trunk/src/VBox/Devices/Graphics/DevVGA.cpp (modified) (2 diffs)

trunk/src/VBox/Devices/Graphics/DevVGA.cpp

@@ -5628 +5628 @@
     Assert(pPciDev == pDevIns->apPciDevs[0]);
 
-    int rc = PDMDevHlpCritSectEnter(pDevIns, &pThis->CritSect, VERR_SEM_BUSY);
-    AssertRC(rc);
-
+    /* Note! We cannot take the device lock here as that would create a lock order
+             problem as the caller has taken the PDM lock prior to calling us.  If
+             we did, we will get trouble later when raising interrupts while owning
+             the device lock (e.g. vmsvgaR3FifoLoop). */
+
+    int rc;
     if (GCPhysAddress != NIL_RTGCPHYS)
     {
@@ -5678 +5681 @@
         /* NB: VBE_DISPI_INDEX_FB_BASE_HI is left unchanged here. */
     }
-    PDMDevHlpCritSectLeave(pDevIns, &pThis->CritSect);
     return rc;
 }