[cgutman] 54418: [HALX86] - Do not allow software interrupts to preempt code running with interrupts disabled during KfLowerIrql

Author: cgutman
Date: Fri Nov 18 18:53:41 2011
New Revision: 54418

URL: http://svn.reactos.org/svn/reactos?rev=54418&view=rev
Log:
[HALX86]
- Do not allow software interrupts to preempt code running with interrupts disabled during KfLowerIrql

Modified:
    trunk/reactos/hal/halx86/up/pic.c

Modified: trunk/reactos/hal/halx86/up/pic.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/hal/halx86/up/pic.c?rev=544...
==============================================================================
--- trunk/reactos/hal/halx86/up/pic.c [iso-8859-1] (original)
+++ trunk/reactos/hal/halx86/up/pic.c [iso-8859-1] Fri Nov 18 18:53:41 2011
@@ -665,26 +665,30 @@

/* Set old IRQL */
     Pcr->Irql = OldIrql;
-    
-    /* Check for pending software interrupts and compare with current IRQL */
-    PendingIrqlMask = Pcr->IRR & FindHigherIrqlMask[OldIrql];
-    if (PendingIrqlMask)
-    {
-        /* Check if pending IRQL affects hardware state */
-        BitScanReverse(&PendingIrql, PendingIrqlMask);
-        if (PendingIrql > DISPATCH_LEVEL)
+
+    /* Make sure interrupts were enabled */
+    if (EFlags & EFLAGS_INTERRUPT_MASK)
+    {
+        /* Check for pending software interrupts and compare with current IRQL */
+        PendingIrqlMask = Pcr->IRR & FindHigherIrqlMask[OldIrql];
+        if (PendingIrqlMask)
         {
-            /* Set new PIC mask */
-            Mask.Both = Pcr->IDR;
-            __outbyte(PIC1_DATA_PORT, Mask.Master);
-            __outbyte(PIC2_DATA_PORT, Mask.Slave);
-            
-            /* Clear IRR bit */
-            Pcr->IRR ^= (1 << PendingIrql);
+            /* Check if pending IRQL affects hardware state */
+            BitScanReverse(&PendingIrql, PendingIrqlMask);
+            if (PendingIrql > DISPATCH_LEVEL)
+            {
+                /* Set new PIC mask */
+                Mask.Both = Pcr->IDR;
+                __outbyte(PIC1_DATA_PORT, Mask.Master);
+                __outbyte(PIC2_DATA_PORT, Mask.Slave);
+
+                /* Clear IRR bit */
+                Pcr->IRR ^= (1 << PendingIrql);
+            }
+
+            /* Now handle pending interrupt */
+            SWInterruptHandlerTable[PendingIrql]();
         }
-    
-        /* Now handle pending interrupt */
-        SWInterruptHandlerTable[PendingIrql]();
     }

/* Restore interrupt state */