[aandrejevic] 65272: [FAST486] Make sure the corrected prefetch address contains the block we're trying to read.

Author: aandrejevic
Date: Wed Nov  5 20:21:32 2014
New Revision: 65272

URL: http://svn.reactos.org/svn/reactos?rev=65272&view=rev
Log:
[FAST486]
Make sure the corrected prefetch address contains the block we're trying to read.


Modified:
    trunk/reactos/lib/fast486/common.c

Modified: trunk/reactos/lib/fast486/common.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/fast486/common.c?rev=6…
==============================================================================
--- trunk/reactos/lib/fast486/common.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/fast486/common.c	[iso-8859-1] Wed Nov  5 20:21:32 2014
@@ -106,6 +106,13 @@
             /* We mustn't prefetch across a page boundary */
             State->PrefetchAddress = PAGE_ALIGN(State->PrefetchAddress)
                                      | (FAST486_PAGE_SIZE - FAST486_CACHE_SIZE);
+
+            if ((LinearAddress - State->PrefetchAddress + Size) >=
FAST486_CACHE_SIZE)
+            {
+                /* We can't prefetch without possibly violating page permissions */
+                State->PrefetchValid = FALSE;
+                return Fast486ReadLinearMemory(State, LinearAddress, Buffer, Size);
+            }
         }
 
         /* Prefetch */