Changeset 19956 in vbox for trunk/src/VBox/Runtime/r0drv/darwin/memobj-r0drv-darwin.cpp

Timestamp:

May 24, 2009 2:34:58 AM (16 years ago)

Author:

vboxsync

Message:

memobj-r0drv-darwin.cpp: Added an ugly hack in rtR0MemObjNativeMapKernel that touches all the pages in the mapping to make sure there are page table entries for them. Need to take a second look at this later...

File:

• trunk/src/VBox/Runtime/r0drv/darwin/memobj-r0drv-darwin.cpp (modified) (2 diffs)

trunk/src/VBox/Runtime/r0drv/darwin/memobj-r0drv-darwin.cpp

@@ -36 +36 @@
 
 #include <iprt/memobj.h>
+
 #include <iprt/alloc.h>
+#include <iprt/asm.h>
 #include <iprt/assert.h>
 #include <iprt/log.h>
 #include <iprt/param.h>
+#include <iprt/process.h>
 #include <iprt/string.h>
-#include <iprt/process.h>
+
 #include "internal/memobj.h"
 
@@ -508 +511 @@
             {
                 /*
+                 * HACK ALERT!
+                 *
+                 * Touch the pages to force the kernel to create  the page
+                 * table entries. This is necessary since the kernel gets
+                 * upset if we take a page fault when preemption is disabled
+                 * and/or we own a simple lock. It has no problems with us
+                 * disabling interrupts when taking the traps, weird stuff.
+                 */
+                uint32_t volatile  *pu32   = (uint32_t volatile *)pv;
+                size_t              cbLeft = cbSub;
+                for (;;)
+                {
+                    ASMAtomicCmpXchgU32(pu32, 0xdeadbeef, 0xdeadbeef);
+                    if (cbLeft <= PAGE_SIZE)
+                        break;
+                    cbLeft -= PAGE_SIZE;
+                    pu32 += PAGE_SIZE / sizeof(uint32_t);
+                }
+
+                /*
                  * Create the IPRT memory object.
                  */