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--- xnu/xnu-10002.1.13/iokit/Kernel/IOBufferMemoryDescriptor.cpp
+++ xnu/xnu-12377.121.6/iokit/Kernel/IOBufferMemoryDescriptor.cpp
@@ -38,6 +38,8 @@
#include <libkern/OSDebug.h>
#include <mach/mach_vm.h>
+#include <vm/vm_kern_xnu.h>
+
#include "IOKitKernelInternal.h"
#ifdef IOALLOCDEBUG
@@ -71,6 +73,12 @@
kInternalFlagInit = 0x00000008,
kInternalFlagHasPointers = 0x00000010,
kInternalFlagGuardPages = 0x00000020,
+ /**
+ * Should the IOBMD behave as if it has no kernel mapping for the
+ * underlying buffer? Note that this does not necessarily imply the
+ * existence (or non-existence) of a kernel mapping.
+ */
+ kInternalFlagAsIfUnmapped = 0x00000040,
};
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
@@ -89,8 +97,8 @@
vm_address_t vmaddr = 0;
kma_flags_t kma_flags = KMA_ZERO;
- if (kheap == KHEAP_DATA_BUFFERS) {
- kma_flags = (kma_flags_t) (kma_flags | KMA_DATA);
+ if (kheap == KHEAP_DATA_SHARED) {
+ kma_flags = (kma_flags_t) (kma_flags | KMA_DATA_SHARED);
}
kr = kmem_alloc(kernel_map, &vmaddr, page_size,
kma_flags, VM_KERN_MEMORY_IOKIT);
@@ -181,13 +189,14 @@
mach_vm_address_t physicalMask)
{
task_t mapTask = NULL;
- kalloc_heap_t kheap = KHEAP_DATA_BUFFERS;
+ kalloc_heap_t kheap = KHEAP_DATA_SHARED;
mach_vm_address_t highestMask = 0;
IOOptionBits iomdOptions = kIOMemoryTypeVirtual64 | kIOMemoryAsReference;
IODMAMapSpecification mapSpec;
bool mapped = false;
bool withCopy = false;
bool mappedOrShared = false;
+ bool noSoftLimit = false;
if (!capacity) {
return false;
@@ -265,8 +274,19 @@
return false;
}
- if ((inTask != kernel_task) && !(options & kIOMemoryPageable)) {
- return false;
+ if (inTask) {
+ if ((inTask != kernel_task) && !(options & kIOMemoryPageable)) {
+ // Cannot create non-pageable memory in user tasks
+ return false;
+ }
+ } else {
+ // Not passing a task implies the memory should not be mapped (or, at
+ // least, should behave as if it were not mapped)
+ _internalFlags |= kInternalFlagAsIfUnmapped;
+
+ // Disable the soft-limit since the mapping, if any, will not escape the
+ // IOBMD.
+ noSoftLimit = true;
}
bzero(&mapSpec, sizeof(mapSpec));
@@ -324,7 +344,7 @@
}
}
_buffer = (void *) IOKernelAllocateWithPhysicalRestrict(kheap,
- capacity, highestMask, alignment, contig);
+ capacity, highestMask, alignment, contig, noSoftLimit);
} else if (_internalFlags & kInternalFlagGuardPages) {
vm_offset_t address = 0;
kern_return_t kr;
@@ -335,8 +355,12 @@
if (((uint32_t) alignment) != alignment) {
return false;
}
- if (kheap == KHEAP_DATA_BUFFERS) {
- kma_flags = (kma_flags_t) (kma_flags | KMA_DATA);
+ if (kheap == KHEAP_DATA_SHARED) {
+ kma_flags = (kma_flags_t) (kma_flags | KMA_DATA_SHARED);
+ }
+
+ if (noSoftLimit) {
+ kma_flags = (kma_flags_t)(kma_flags | KMA_NOSOFTLIMIT);
}
alignMask = (1UL << log2up((uint32_t) alignment)) - 1;
@@ -365,13 +389,20 @@
#endif
}
#endif /* defined(__x86_64__) */
- } else if (alignment > 1) {
+ } else {
+ zalloc_flags_t zflags = Z_ZERO_VM_TAG_BT_BIT;
+ if (noSoftLimit) {
+ zflags = (zalloc_flags_t)(zflags | Z_NOSOFTLIMIT);
+ }
+
/* BEGIN IGNORE CODESTYLE */
__typed_allocators_ignore_push
- _buffer = IOMallocAligned_internal(kheap, capacity, alignment,
- Z_ZERO_VM_TAG_BT_BIT);
- } else {
- _buffer = IOMalloc_internal(kheap, capacity, Z_ZERO_VM_TAG_BT_BIT);
+ if (alignment > 1) {
+ _buffer = IOMallocAligned_internal(kheap, capacity, alignment,
+ zflags);
+ } else {
+ _buffer = IOMalloc_internal(kheap, capacity, zflags);
+ }
__typed_allocators_ignore_pop
/* END IGNORE CODESTYLE */
}
@@ -395,9 +426,6 @@
if (!withCopy) {
mapTask = inTask;
}
- if (NULL == inTask) {
- inTask = kernel_task;
- }
} else if (options & kIOMapCacheMask) {
// Prefetch each page to put entries into the pmap
volatile UInt8 * startAddr = (UInt8 *)_buffer;
@@ -411,11 +439,16 @@
}
}
- _ranges.v64->address = (mach_vm_address_t) pgz_decode(_buffer, _capacity);
+ _ranges.v64->address = (mach_vm_address_t) _buffer;
_ranges.v64->length = _capacity;
- if (!super::initWithOptions(_ranges.v64, 1, 0,
- inTask, iomdOptions, /* System mapper */ NULL)) {
+ if (!super::initWithOptions(
+ /* buffers */ _ranges.v64, /* count */ 1, /* offset */ 0,
+ // Since we handle all "unmapped" behavior internally and our superclass
+ // requires a task, default all unbound IOBMDs to the kernel task.
+ /* task */ inTask ?: kernel_task,
+ /* options */ iomdOptions,
+ /* System mapper */ NULL)) {
return false;
}
@@ -681,7 +714,7 @@
IOMemoryMap * map = NULL;
IOAddressRange * range = _ranges.v64;
vm_offset_t alignment = _alignment;
- kalloc_heap_t kheap = KHEAP_DATA_BUFFERS;
+ kalloc_heap_t kheap = KHEAP_DATA_SHARED;
vm_size_t rsize;
if (alignment >= page_size) {
@@ -744,7 +777,8 @@
#endif /* defined(__x86_64__) */
} else if (kInternalFlagGuardPages & internalFlags) {
vm_offset_t allocation = (vm_offset_t)buffer - page_size;
- kmem_free(kernel_map, allocation, size + page_size * 2);
+ kmem_free(kernel_map, allocation, size + page_size * 2,
+ (kmf_flags_t)(KMF_GUARD_FIRST | KMF_GUARD_LAST));
#if IOALLOCDEBUG
OSAddAtomicLong(-size, &debug_iomalloc_size);
#endif
@@ -823,7 +857,7 @@
bool
IOBufferMemoryDescriptor::appendBytes(const void * bytes, vm_size_t withLength)
{
- vm_size_t actualBytesToCopy = min(withLength, _capacity - _length);
+ vm_size_t actualBytesToCopy = IOMin(withLength, _capacity - _length);
IOByteCount offset;
assert(_length <= _capacity);
@@ -850,6 +884,10 @@
void *
IOBufferMemoryDescriptor::getBytesNoCopy()
{
+ if (__improbable(_internalFlags & kInternalFlagAsIfUnmapped)) {
+ return NULL;
+ }
+
if (kIOMemoryTypePhysical64 == (_flags & kIOMemoryTypeMask)) {
return _buffer;
} else {
@@ -867,6 +905,10 @@
IOBufferMemoryDescriptor::getBytesNoCopy(vm_size_t start, vm_size_t withLength)
{
IOVirtualAddress address;
+
+ if (__improbable(_internalFlags & kInternalFlagAsIfUnmapped)) {
+ return NULL;
+ }
if ((start + withLength) < start) {
return NULL;