xnu-4570.1.46.tar.gz

[apple/xnu.git] / iokit / Kernel / IOBufferMemoryDescriptor.cpp

diff --git a/iokit/Kernel/IOBufferMemoryDescriptor.cpp b/iokit/Kernel/IOBufferMemoryDescriptor.cpp
index 046274c5945f768b2e6a3e6baff6ed77714b12fc..b3ff13ddaed3dfc816b0447ab573c5ade716ce0f 100644 (file)
--- a/iokit/Kernel/IOBufferMemoryDescriptor.cpp
+++ b/iokit/Kernel/IOBufferMemoryDescriptor.cpp
@@ -66,7 +66,8 @@ enum
 {
     kInternalFlagPhysical      = 0x00000001,
     kInternalFlagPageSized     = 0x00000002,
-    kInternalFlagPageAllocated = 0x00000004
+    kInternalFlagPageAllocated = 0x00000004,
+    kInternalFlagInit          = 0x00000008
 };
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
@@ -289,6 +290,11 @@ bool IOBufferMemoryDescriptor::initWithPhysicalMask(
                                inTask, iomdOptions, /* System mapper */ 0))
        return false;
 
+    _internalFlags |= kInternalFlagInit;
+#if IOTRACKING
+    if (!(options & kIOMemoryPageable))        trackingAccumSize(capacity);
+#endif /* IOTRACKING */
+
     // give any system mapper the allocation params
     if (kIOReturnSuccess != dmaCommandOperation(kIOMDAddDMAMapSpec, 
                                                &mapSpec, sizeof(mapSpec)))
@@ -488,19 +494,26 @@ void IOBufferMemoryDescriptor::free()
            map->release();
     }
 
+    if ((options & kIOMemoryPageable)
+        || (kInternalFlagPageSized & internalFlags)) size = round_page(size);
+
+#if IOTRACKING
+    if (!(options & kIOMemoryPageable)
+       && buffer
+       && (kInternalFlagInit & _internalFlags)) trackingAccumSize(-size);
+#endif /* IOTRACKING */
+
     /* super::free may unwire - deallocate buffer afterwards */
     super::free();
 
     if (options & kIOMemoryPageable)
     {
 #if IOALLOCDEBUG
-       OSAddAtomicLong(-(round_page(size)), &debug_iomallocpageable_size);
+       OSAddAtomicLong(-size, &debug_iomallocpageable_size);
 #endif
     }
     else if (buffer)
     {
-       if (kInternalFlagPageSized & internalFlags) size = round_page(size);
-
         if (kInternalFlagPhysical & internalFlags)
         {
             IOKernelFreePhysical((mach_vm_address_t) buffer, size);
@@ -626,6 +639,9 @@ void *
 IOBufferMemoryDescriptor::getBytesNoCopy(vm_size_t start, vm_size_t withLength)
 {
     IOVirtualAddress address;
+
+    if ((start + withLength) < start) return 0;
+
     if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask))
        address = (IOVirtualAddress) _buffer;
     else