1 //===-- DynamicLoaderDarwinKernel.cpp -----------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/lldb-python.h"
11 
12 #include "lldb/Utility/SafeMachO.h"
13 
14 #include "lldb/Breakpoint/StoppointCallbackContext.h"
15 #include "lldb/Core/DataBuffer.h"
16 #include "lldb/Core/DataBufferHeap.h"
17 #include "lldb/Core/Debugger.h"
18 #include "lldb/Core/Log.h"
19 #include "lldb/Core/Module.h"
20 #include "lldb/Core/ModuleSpec.h"
21 #include "lldb/Core/PluginManager.h"
22 #include "lldb/Core/Section.h"
23 #include "lldb/Core/State.h"
24 #include "lldb/Core/StreamFile.h"
25 #include "lldb/Host/Symbols.h"
26 #include "lldb/Symbol/ObjectFile.h"
27 #include "lldb/Target/RegisterContext.h"
28 #include "lldb/Target/StackFrame.h"
29 #include "lldb/Target/Target.h"
30 #include "lldb/Target/Thread.h"
31 #include "lldb/Target/ThreadPlanRunToAddress.h"
32 #include "Plugins/Platform/MacOSX/PlatformDarwinKernel.h"
33 
34 #include "DynamicLoaderDarwinKernel.h"
35 
36 //#define ENABLE_DEBUG_PRINTF // COMMENT THIS LINE OUT PRIOR TO CHECKIN
37 #ifdef ENABLE_DEBUG_PRINTF
38 #include <stdio.h>
39 #define DEBUG_PRINTF(fmt, ...) printf(fmt, ## __VA_ARGS__)
40 #else
41 #define DEBUG_PRINTF(fmt, ...)
42 #endif
43 
44 using namespace lldb;
45 using namespace lldb_private;
46 
47 // Progressively greater amounts of scanning we will allow
48 // For some targets very early in startup, we can't do any random reads of memory or we can crash the device
49 // so a setting is needed that can completely disable the KASLR scans.
50 
51 enum KASLRScanType
52 {
53     eKASLRScanNone = 0,         // No reading into the inferior at all
54     eKASLRScanLowgloAddresses,  // Check one word of memory for a possible kernel addr, then see if a kernel is there
55     eKASLRScanNearPC,           // Scan backwards from the current $pc looking for kernel; checking at 96 locations total
56     eKASLRScanExhaustiveScan    // Scan through the entire possible kernel address range looking for a kernel
57 };
58 
59 OptionEnumValueElement
60 g_kaslr_kernel_scan_enum_values[] =
61 {
62     { eKASLRScanNone,            "none",            "Do not read memory looking for a Darwin kernel when attaching." },
63     { eKASLRScanLowgloAddresses, "basic",           "Check for the Darwin kernel's load addr in the lowglo page (boot-args=debug) only." },
64     { eKASLRScanNearPC,          "fast-scan",       "Scan near the pc value on attach to find the Darwin kernel's load address."},
65     { eKASLRScanExhaustiveScan,  "exhaustive-scan", "Scan through the entire potential address range of Darwin kernel (only on 32-bit targets)."},
66     { 0, NULL, NULL }
67 };
68 
69 static PropertyDefinition
70 g_properties[] =
71 {
72     { "load-kexts" , OptionValue::eTypeBoolean, true, true, NULL, NULL, "Automatically loads kext images when attaching to a kernel." },
73     { "scan-type",   OptionValue::eTypeEnum,    true, eKASLRScanNearPC, NULL, g_kaslr_kernel_scan_enum_values, "Control how many reads lldb will make while searching for a Darwin kernel on attach." },
74     {  NULL        , OptionValue::eTypeInvalid, false, 0  , NULL, NULL, NULL  }
75 };
76 
77 enum {
78     ePropertyLoadKexts,
79     ePropertyScanType
80 };
81 
82 class DynamicLoaderDarwinKernelProperties : public Properties
83 {
84 public:
85 
86     static ConstString &
87     GetSettingName ()
88     {
89         static ConstString g_setting_name("darwin-kernel");
90         return g_setting_name;
91     }
92 
93     DynamicLoaderDarwinKernelProperties() :
94         Properties ()
95     {
96         m_collection_sp.reset (new OptionValueProperties(GetSettingName()));
97         m_collection_sp->Initialize(g_properties);
98     }
99 
100     virtual
101     ~DynamicLoaderDarwinKernelProperties()
102     {
103     }
104 
105     bool
106     GetLoadKexts() const
107     {
108         const uint32_t idx = ePropertyLoadKexts;
109         return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
110     }
111 
112     KASLRScanType
113     GetScanType() const
114     {
115         const uint32_t idx = ePropertyScanType;
116         return (KASLRScanType) m_collection_sp->GetPropertyAtIndexAsEnumeration (NULL, idx, g_properties[idx].default_uint_value);
117     }
118 
119 
120 };
121 
122 typedef std::shared_ptr<DynamicLoaderDarwinKernelProperties> DynamicLoaderDarwinKernelPropertiesSP;
123 
124 static const DynamicLoaderDarwinKernelPropertiesSP &
125 GetGlobalProperties()
126 {
127     static DynamicLoaderDarwinKernelPropertiesSP g_settings_sp;
128     if (!g_settings_sp)
129         g_settings_sp.reset (new DynamicLoaderDarwinKernelProperties ());
130     return g_settings_sp;
131 }
132 
133 //----------------------------------------------------------------------
134 // Create an instance of this class. This function is filled into
135 // the plugin info class that gets handed out by the plugin factory and
136 // allows the lldb to instantiate an instance of this class.
137 //----------------------------------------------------------------------
138 DynamicLoader *
139 DynamicLoaderDarwinKernel::CreateInstance (Process* process, bool force)
140 {
141     if (!force)
142     {
143         // If the user provided an executable binary and it is not a kernel,
144         // this plugin should not create an instance.
145         Module* exe_module = process->GetTarget().GetExecutableModulePointer();
146         if (exe_module)
147         {
148             ObjectFile *object_file = exe_module->GetObjectFile();
149             if (object_file)
150             {
151                 if (object_file->GetStrata() != ObjectFile::eStrataKernel)
152                 {
153                     return NULL;
154                 }
155             }
156         }
157 
158         // If the target's architecture does not look like an Apple environment,
159         // this plugin should not create an instance.
160         const llvm::Triple &triple_ref = process->GetTarget().GetArchitecture().GetTriple();
161         switch (triple_ref.getOS())
162         {
163             case llvm::Triple::Darwin:
164             case llvm::Triple::MacOSX:
165             case llvm::Triple::IOS:
166                 if (triple_ref.getVendor() != llvm::Triple::Apple)
167                 {
168                    return NULL;
169                 }
170                 break;
171             // If we have triple like armv7-unknown-unknown, we should try looking for a Darwin kernel.
172             case llvm::Triple::UnknownOS:
173                 break;
174             default:
175                 return NULL;
176                 break;
177         }
178     }
179 
180     // At this point if there is an ExecutableModule, it is a kernel and the Target is some variant of an Apple system.
181     // If the Process hasn't provided the kernel load address, we need to look around in memory to find it.
182 
183     addr_t kernel_load_address = SearchForDarwinKernel (process);
184     if (kernel_load_address != LLDB_INVALID_ADDRESS)
185     {
186         process->SetCanJIT(false);
187         return new DynamicLoaderDarwinKernel (process, kernel_load_address);
188     }
189     return NULL;
190 }
191 
192 lldb::addr_t
193 DynamicLoaderDarwinKernel::SearchForDarwinKernel (Process *process)
194 {
195     addr_t kernel_load_address = process->GetImageInfoAddress();
196     if (kernel_load_address == LLDB_INVALID_ADDRESS)
197     {
198         kernel_load_address = SearchForKernelAtSameLoadAddr (process);
199         if (kernel_load_address == LLDB_INVALID_ADDRESS)
200         {
201             kernel_load_address = SearchForKernelWithDebugHints (process);
202             if (kernel_load_address == LLDB_INVALID_ADDRESS)
203             {
204                 kernel_load_address = SearchForKernelNearPC (process);
205                 if (kernel_load_address == LLDB_INVALID_ADDRESS)
206                 {
207                     kernel_load_address = SearchForKernelViaExhaustiveSearch (process);
208                 }
209             }
210         }
211     }
212     return kernel_load_address;
213 }
214 
215 //----------------------------------------------------------------------
216 // Check if the kernel binary is loaded in memory without a slide.
217 // First verify that the ExecutableModule is a kernel before we proceed.
218 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
219 //----------------------------------------------------------------------
220 lldb::addr_t
221 DynamicLoaderDarwinKernel::SearchForKernelAtSameLoadAddr (Process *process)
222 {
223     Module *exe_module = process->GetTarget().GetExecutableModulePointer();
224     if (exe_module == NULL)
225         return LLDB_INVALID_ADDRESS;
226 
227     ObjectFile *exe_objfile = exe_module->GetObjectFile();
228     if (exe_objfile == NULL)
229         return LLDB_INVALID_ADDRESS;
230 
231     if (exe_objfile->GetType() != ObjectFile::eTypeExecutable || exe_objfile->GetStrata() != ObjectFile::eStrataKernel)
232         return LLDB_INVALID_ADDRESS;
233 
234     if (!exe_objfile->GetHeaderAddress().IsValid())
235         return LLDB_INVALID_ADDRESS;
236 
237     if (CheckForKernelImageAtAddress (exe_objfile->GetHeaderAddress().GetFileAddress(), process) == exe_module->GetUUID())
238         return exe_objfile->GetHeaderAddress().GetFileAddress();
239 
240     return LLDB_INVALID_ADDRESS;
241 }
242 
243 //----------------------------------------------------------------------
244 // If the debug flag is included in the boot-args nvram setting, the kernel's load address
245 // will be noted in the lowglo page at a fixed address
246 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
247 //----------------------------------------------------------------------
248 lldb::addr_t
249 DynamicLoaderDarwinKernel::SearchForKernelWithDebugHints (Process *process)
250 {
251     if (GetGlobalProperties()->GetScanType() == eKASLRScanNone)
252         return LLDB_INVALID_ADDRESS;
253 
254     Error read_err;
255     addr_t addr = LLDB_INVALID_ADDRESS;
256     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
257     {
258         addr = process->ReadUnsignedIntegerFromMemory (0xffffff8000002010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
259     }
260     else
261     {
262         addr = process->ReadUnsignedIntegerFromMemory (0xffff0110, 4, LLDB_INVALID_ADDRESS, read_err);
263     }
264 
265     if (addr == 0)
266         addr = LLDB_INVALID_ADDRESS;
267 
268     if (addr != LLDB_INVALID_ADDRESS)
269     {
270         if (CheckForKernelImageAtAddress (addr, process).IsValid())
271             return addr;
272     }
273 
274     return LLDB_INVALID_ADDRESS;
275 }
276 
277 //----------------------------------------------------------------------
278 // If the kernel is currently executing when lldb attaches, and we don't have
279 // a better way of finding the kernel's load address, try searching backwards
280 // from the current pc value looking for the kernel's Mach header in memory.
281 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
282 //----------------------------------------------------------------------
283 lldb::addr_t
284 DynamicLoaderDarwinKernel::SearchForKernelNearPC (Process *process)
285 {
286     if (GetGlobalProperties()->GetScanType() == eKASLRScanNone
287         || GetGlobalProperties()->GetScanType() == eKASLRScanLowgloAddresses)
288     {
289         return LLDB_INVALID_ADDRESS;
290     }
291 
292     ThreadSP thread = process->GetThreadList().GetSelectedThread ();
293     if (thread.get() == NULL)
294         return LLDB_INVALID_ADDRESS;
295     addr_t pc = thread->GetRegisterContext ()->GetPC(LLDB_INVALID_ADDRESS);
296 
297     if (pc == LLDB_INVALID_ADDRESS)
298         return LLDB_INVALID_ADDRESS;
299 
300     addr_t kernel_range_low;
301     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
302     {
303         kernel_range_low = 1ULL << 63;
304     }
305     else
306     {
307         kernel_range_low = 1ULL << 31;
308     }
309 
310     // Outside the normal kernel address range, this is probably userland code running right now
311     if (pc < kernel_range_low)
312         return LLDB_INVALID_ADDRESS;
313 
314     // The kernel will load at at one megabyte boundary (0x100000), or at that boundary plus
315     // an offset of one page (0x1000) or two, depending on the device.
316 
317     // Round the current pc down to the nearest one megabyte boundary - the place where we will start searching.
318     addr_t addr = pc & ~0xfffff;
319 
320     int i = 0;
321     while (i < 32 && pc >= kernel_range_low)
322     {
323         if (CheckForKernelImageAtAddress (addr, process).IsValid())
324             return addr;
325         if (CheckForKernelImageAtAddress (addr + 0x1000, process).IsValid())
326             return addr + 0x1000;
327         if (CheckForKernelImageAtAddress (addr + 0x2000, process).IsValid())
328             return addr + 0x2000;
329         if (CheckForKernelImageAtAddress (addr + 0x4000, process).IsValid())
330             return addr + 0x4000;
331         i++;
332         addr -= 0x100000;
333     }
334 
335     return LLDB_INVALID_ADDRESS;
336 }
337 
338 //----------------------------------------------------------------------
339 // Scan through the valid address range for a kernel binary.
340 // This is uselessly slow in 64-bit environments so we don't even try it.
341 // This scan is not enabled by default even for 32-bit targets.
342 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
343 //----------------------------------------------------------------------
344 lldb::addr_t
345 DynamicLoaderDarwinKernel::SearchForKernelViaExhaustiveSearch (Process *process)
346 {
347     if (GetGlobalProperties()->GetScanType() != eKASLRScanExhaustiveScan)
348     {
349         return LLDB_INVALID_ADDRESS;
350     }
351 
352     addr_t kernel_range_low, kernel_range_high;
353     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
354     {
355         kernel_range_low = 1ULL << 63;
356         kernel_range_high = UINT64_MAX;
357     }
358     else
359     {
360         kernel_range_low = 1ULL << 31;
361         kernel_range_high = UINT32_MAX;
362     }
363 
364     // Stepping through memory at one-megabyte resolution looking for a kernel
365     // rarely works (fast enough) with a 64-bit address space -- for now, let's
366     // not even bother.  We may be attaching to something which *isn't* a kernel
367     // and we don't want to spin for minutes on-end looking for a kernel.
368     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
369         return LLDB_INVALID_ADDRESS;
370 
371     addr_t addr = kernel_range_low;
372 
373     while (addr >= kernel_range_low && addr < kernel_range_high)
374     {
375         if (CheckForKernelImageAtAddress (addr, process).IsValid())
376             return addr;
377         if (CheckForKernelImageAtAddress (addr + 0x1000, process).IsValid())
378             return addr + 0x1000;
379         if (CheckForKernelImageAtAddress (addr + 0x2000, process).IsValid())
380             return addr + 0x2000;
381         if (CheckForKernelImageAtAddress (addr + 0x4000, process).IsValid())
382             return addr + 0x4000;
383         addr += 0x100000;
384     }
385     return LLDB_INVALID_ADDRESS;
386 }
387 
388 //----------------------------------------------------------------------
389 // Given an address in memory, look to see if there is a kernel image at that
390 // address.
391 // Returns a UUID; if a kernel was not found at that address, UUID.IsValid() will be false.
392 //----------------------------------------------------------------------
393 lldb_private::UUID
394 DynamicLoaderDarwinKernel::CheckForKernelImageAtAddress (lldb::addr_t addr, Process *process)
395 {
396     if (addr == LLDB_INVALID_ADDRESS)
397         return UUID();
398 
399     // First try a quick test -- read the first 4 bytes and see if there is a valid Mach-O magic field there
400     // (the first field of the mach_header/mach_header_64 struct).
401 
402     Error read_error;
403     uint64_t result = process->ReadUnsignedIntegerFromMemory (addr, 4, LLDB_INVALID_ADDRESS, read_error);
404     if (result != llvm::MachO::MH_MAGIC_64
405         && result != llvm::MachO::MH_MAGIC
406         && result != llvm::MachO::MH_CIGAM
407         && result != llvm::MachO::MH_CIGAM_64)
408     {
409         return UUID();
410     }
411 
412     // Read the mach header and see whether it looks like a kernel
413     llvm::MachO::mach_header header;
414     if (process->DoReadMemory (addr, &header, sizeof(header), read_error) != sizeof(header))
415         return UUID();
416 
417     if (header.magic == llvm::MachO::MH_CIGAM ||
418         header.magic == llvm::MachO::MH_CIGAM_64)
419     {
420         header.magic        = llvm::ByteSwap_32(header.magic);
421         header.cputype      = llvm::ByteSwap_32(header.cputype);
422         header.cpusubtype   = llvm::ByteSwap_32(header.cpusubtype);
423         header.filetype     = llvm::ByteSwap_32(header.filetype);
424         header.ncmds        = llvm::ByteSwap_32(header.ncmds);
425         header.sizeofcmds   = llvm::ByteSwap_32(header.sizeofcmds);
426         header.flags        = llvm::ByteSwap_32(header.flags);
427     }
428 
429     // A kernel is an executable which does not have the dynamic link object flag set.
430     if (header.filetype == llvm::MachO::MH_EXECUTE
431         && (header.flags & llvm::MachO::MH_DYLDLINK) == 0)
432     {
433         // Create a full module to get the UUID
434         ModuleSP memory_module_sp = process->ReadModuleFromMemory (FileSpec ("temp_mach_kernel", false), addr);
435         if (!memory_module_sp.get())
436             return UUID();
437 
438         ObjectFile *exe_objfile = memory_module_sp->GetObjectFile();
439         if (exe_objfile == NULL)
440             return UUID();
441 
442         if (exe_objfile->GetType() == ObjectFile::eTypeExecutable && exe_objfile->GetStrata() == ObjectFile::eStrataKernel)
443         {
444             ArchSpec kernel_arch (eArchTypeMachO, header.cputype, header.cpusubtype);
445             if (!process->GetTarget().GetArchitecture().IsCompatibleMatch(kernel_arch))
446             {
447                 process->GetTarget().SetArchitecture (kernel_arch);
448             }
449             return memory_module_sp->GetUUID();
450         }
451     }
452 
453     return UUID();
454 }
455 
456 //----------------------------------------------------------------------
457 // Constructor
458 //----------------------------------------------------------------------
459 DynamicLoaderDarwinKernel::DynamicLoaderDarwinKernel (Process* process, lldb::addr_t kernel_addr) :
460     DynamicLoader(process),
461     m_kernel_load_address (kernel_addr),
462     m_kernel(),
463     m_kext_summary_header_ptr_addr (),
464     m_kext_summary_header_addr (),
465     m_kext_summary_header (),
466     m_known_kexts (),
467     m_mutex(Mutex::eMutexTypeRecursive),
468     m_break_id (LLDB_INVALID_BREAK_ID)
469 {
470     PlatformSP platform_sp(Platform::FindPlugin (process, PlatformDarwinKernel::GetPluginNameStatic ()));
471     // Only select the darwin-kernel Platform if we've been asked to load kexts.
472     // It can take some time to scan over all of the kext info.plists and that
473     // shouldn't be done if kext loading is explicitly disabled.
474     if (platform_sp.get() && GetGlobalProperties()->GetLoadKexts())
475     {
476         process->GetTarget().SetPlatform (platform_sp);
477     }
478 }
479 
480 //----------------------------------------------------------------------
481 // Destructor
482 //----------------------------------------------------------------------
483 DynamicLoaderDarwinKernel::~DynamicLoaderDarwinKernel()
484 {
485     Clear(true);
486 }
487 
488 void
489 DynamicLoaderDarwinKernel::UpdateIfNeeded()
490 {
491     LoadKernelModuleIfNeeded();
492     SetNotificationBreakpointIfNeeded ();
493 }
494 //------------------------------------------------------------------
495 /// Called after attaching a process.
496 ///
497 /// Allow DynamicLoader plug-ins to execute some code after
498 /// attaching to a process.
499 //------------------------------------------------------------------
500 void
501 DynamicLoaderDarwinKernel::DidAttach ()
502 {
503     PrivateInitialize(m_process);
504     UpdateIfNeeded();
505 }
506 
507 //------------------------------------------------------------------
508 /// Called after attaching a process.
509 ///
510 /// Allow DynamicLoader plug-ins to execute some code after
511 /// attaching to a process.
512 //------------------------------------------------------------------
513 void
514 DynamicLoaderDarwinKernel::DidLaunch ()
515 {
516     PrivateInitialize(m_process);
517     UpdateIfNeeded();
518 }
519 
520 
521 //----------------------------------------------------------------------
522 // Clear out the state of this class.
523 //----------------------------------------------------------------------
524 void
525 DynamicLoaderDarwinKernel::Clear (bool clear_process)
526 {
527     Mutex::Locker locker(m_mutex);
528 
529     if (m_process->IsAlive() && LLDB_BREAK_ID_IS_VALID(m_break_id))
530         m_process->ClearBreakpointSiteByID(m_break_id);
531 
532     if (clear_process)
533         m_process = NULL;
534     m_kernel.Clear();
535     m_known_kexts.clear();
536     m_kext_summary_header_ptr_addr.Clear();
537     m_kext_summary_header_addr.Clear();
538     m_break_id = LLDB_INVALID_BREAK_ID;
539 }
540 
541 
542 bool
543 DynamicLoaderDarwinKernel::KextImageInfo::LoadImageAtFileAddress (Process *process)
544 {
545     if (IsLoaded())
546         return true;
547 
548     if (m_module_sp)
549     {
550         bool changed = false;
551         if (m_module_sp->SetLoadAddress (process->GetTarget(), 0, true, changed))
552             m_load_process_stop_id = process->GetStopID();
553     }
554     return false;
555 }
556 
557 void
558 DynamicLoaderDarwinKernel::KextImageInfo::SetModule (ModuleSP module_sp)
559 {
560     m_module_sp = module_sp;
561     if (module_sp.get() && module_sp->GetObjectFile())
562     {
563         if (module_sp->GetObjectFile()->GetType() == ObjectFile::eTypeExecutable
564             && module_sp->GetObjectFile()->GetStrata() == ObjectFile::eStrataKernel)
565         {
566             m_kernel_image = true;
567         }
568         else
569         {
570             m_kernel_image = false;
571         }
572     }
573 }
574 
575 ModuleSP
576 DynamicLoaderDarwinKernel::KextImageInfo::GetModule ()
577 {
578     return m_module_sp;
579 }
580 
581 void
582 DynamicLoaderDarwinKernel::KextImageInfo::SetLoadAddress (addr_t load_addr)
583 {
584     m_load_address = load_addr;
585 }
586 
587 addr_t
588 DynamicLoaderDarwinKernel::KextImageInfo::GetLoadAddress () const
589 {
590     return m_load_address;
591 }
592 
593 uint64_t
594 DynamicLoaderDarwinKernel::KextImageInfo::GetSize () const
595 {
596     return m_size;
597 }
598 
599 void
600 DynamicLoaderDarwinKernel::KextImageInfo::SetSize (uint64_t size)
601 {
602     m_size = size;
603 }
604 
605 uint32_t
606 DynamicLoaderDarwinKernel::KextImageInfo::GetProcessStopId () const
607 {
608     return m_load_process_stop_id;
609 }
610 
611 void
612 DynamicLoaderDarwinKernel::KextImageInfo::SetProcessStopId (uint32_t stop_id)
613 {
614     m_load_process_stop_id = stop_id;
615 }
616 
617 bool
618 DynamicLoaderDarwinKernel::KextImageInfo::operator== (const KextImageInfo &rhs)
619 {
620     if (m_uuid.IsValid() || rhs.GetUUID().IsValid())
621     {
622         if (m_uuid == rhs.GetUUID())
623         {
624             return true;
625         }
626         return false;
627     }
628 
629     if (m_name == rhs.GetName() && m_load_address == rhs.GetLoadAddress())
630         return true;
631 
632     return false;
633 }
634 
635 void
636 DynamicLoaderDarwinKernel::KextImageInfo::SetName (const char *name)
637 {
638     m_name = name;
639 }
640 
641 std::string
642 DynamicLoaderDarwinKernel::KextImageInfo::GetName () const
643 {
644     return m_name;
645 }
646 
647 void
648 DynamicLoaderDarwinKernel::KextImageInfo::SetUUID (const UUID &uuid)
649 {
650     m_uuid = uuid;
651 }
652 
653 UUID
654 DynamicLoaderDarwinKernel::KextImageInfo::GetUUID () const
655 {
656     return m_uuid;
657 }
658 
659 // Given the m_load_address from the kext summaries, and a UUID, try to create an in-memory
660 // Module at that address.  Require that the MemoryModule have a matching UUID and detect
661 // if this MemoryModule is a kernel or a kext.
662 //
663 // Returns true if m_memory_module_sp is now set to a valid Module.
664 
665 bool
666 DynamicLoaderDarwinKernel::KextImageInfo::ReadMemoryModule (Process *process)
667 {
668     if (m_memory_module_sp.get() != NULL)
669         return true;
670     if (m_load_address == LLDB_INVALID_ADDRESS)
671         return false;
672 
673     FileSpec file_spec;
674     file_spec.SetFile (m_name.c_str(), false);
675 
676     ModuleSP memory_module_sp = process->ReadModuleFromMemory (file_spec, m_load_address);
677 
678     if (memory_module_sp.get() == NULL)
679         return false;
680 
681     bool is_kernel = false;
682     if (memory_module_sp->GetObjectFile())
683     {
684         if (memory_module_sp->GetObjectFile()->GetType() == ObjectFile::eTypeExecutable
685             && memory_module_sp->GetObjectFile()->GetStrata() == ObjectFile::eStrataKernel)
686         {
687             is_kernel = true;
688         }
689         else if (memory_module_sp->GetObjectFile()->GetType() == ObjectFile::eTypeSharedLibrary)
690         {
691             is_kernel = false;
692         }
693     }
694 
695     // If this is a kext, and the kernel specified what UUID we should find at this
696     // load address, require that the memory module have a matching UUID or something
697     // has gone wrong and we should discard it.
698     if (m_uuid.IsValid())
699     {
700         if (m_uuid != memory_module_sp->GetUUID())
701         {
702             return false;
703         }
704     }
705 
706     // If the in-memory Module has a UUID, let's use that.
707     if (!m_uuid.IsValid() && memory_module_sp->GetUUID().IsValid())
708     {
709         m_uuid = memory_module_sp->GetUUID();
710     }
711 
712     m_memory_module_sp = memory_module_sp;
713     m_kernel_image = is_kernel;
714     if (is_kernel)
715     {
716         if (memory_module_sp->GetArchitecture().IsValid())
717         {
718             process->GetTarget().SetArchitecture(memory_module_sp->GetArchitecture());
719         }
720         if (m_uuid.IsValid())
721         {
722             Module* exe_module = process->GetTarget().GetExecutableModulePointer();
723             if (exe_module && exe_module->GetUUID().IsValid())
724             {
725                 if (m_uuid != exe_module->GetUUID())
726                 {
727                     Stream *s = process->GetTarget().GetDebugger().GetOutputFile().get();
728                     if (s)
729                     {
730                         s->Printf ("warning: Host-side kernel file has Mach-O UUID of %s but remote kernel has a UUID of %s -- a mismatched kernel file will result in a poor debugger experience.\n",
731                                    exe_module->GetUUID().GetAsString().c_str(),
732                                    m_uuid.GetAsString().c_str());
733                         s->Flush ();
734                     }
735                 }
736             }
737         }
738     }
739 
740     return true;
741 }
742 
743 bool
744 DynamicLoaderDarwinKernel::KextImageInfo::IsKernel () const
745 {
746     return m_kernel_image == true;
747 }
748 
749 void
750 DynamicLoaderDarwinKernel::KextImageInfo::SetIsKernel (bool is_kernel)
751 {
752     m_kernel_image = is_kernel;
753 }
754 
755 bool
756 DynamicLoaderDarwinKernel::KextImageInfo::LoadImageUsingMemoryModule (Process *process)
757 {
758     if (IsLoaded())
759         return true;
760 
761 
762     Target &target = process->GetTarget();
763 
764     // If we don't have / can't create a memory module for this kext, don't try to load it - we won't
765     // have the correct segment load addresses.
766     if (!ReadMemoryModule (process))
767     {
768         return false;
769     }
770 
771     bool uuid_is_valid = m_uuid.IsValid();
772 
773     if (IsKernel() && uuid_is_valid && m_memory_module_sp.get())
774     {
775         Stream *s = target.GetDebugger().GetOutputFile().get();
776         if (s)
777         {
778             s->Printf ("Kernel UUID: %s\n", m_memory_module_sp->GetUUID().GetAsString().c_str());
779             s->Printf ("Load Address: 0x%" PRIx64 "\n", m_load_address);
780         }
781     }
782 
783     if (!m_module_sp)
784     {
785         // See if the kext has already been loaded into the target, probably by the user doing target modules add.
786         const ModuleList &target_images = target.GetImages();
787         m_module_sp = target_images.FindModule(m_uuid);
788 
789         // Search for the kext on the local filesystem via the UUID
790         if (!m_module_sp && uuid_is_valid)
791         {
792             ModuleSpec module_spec;
793             module_spec.GetUUID() = m_uuid;
794             module_spec.GetArchitecture() = target.GetArchitecture();
795 
796             // For the kernel, we really do need an on-disk file copy of the binary to do anything useful.
797             // This will force a clal to
798             if (IsKernel())
799             {
800                 if (Symbols::DownloadObjectAndSymbolFile (module_spec, true))
801                 {
802                     if (module_spec.GetFileSpec().Exists())
803                     {
804                         m_module_sp.reset(new Module (module_spec.GetFileSpec(), target.GetArchitecture()));
805                         if (m_module_sp.get() && m_module_sp->MatchesModuleSpec (module_spec))
806                         {
807                             ModuleList loaded_module_list;
808                             loaded_module_list.Append (m_module_sp);
809                             target.ModulesDidLoad (loaded_module_list);
810                         }
811                     }
812                 }
813             }
814 
815             // If the current platform is PlatformDarwinKernel, create a ModuleSpec with the filename set
816             // to be the bundle ID for this kext, e.g. "com.apple.filesystems.msdosfs", and ask the platform
817             // to find it.
818             PlatformSP platform_sp (target.GetPlatform());
819             if (!m_module_sp && platform_sp)
820             {
821                 ConstString platform_name (platform_sp->GetPluginName());
822                 static ConstString g_platform_name (PlatformDarwinKernel::GetPluginNameStatic());
823                 if (platform_name == g_platform_name)
824                 {
825                     ModuleSpec kext_bundle_module_spec(module_spec);
826                     FileSpec kext_filespec(m_name.c_str(), false);
827                     kext_bundle_module_spec.GetFileSpec() = kext_filespec;
828                     platform_sp->GetSharedModule (kext_bundle_module_spec, m_module_sp, &target.GetExecutableSearchPaths(), NULL, NULL);
829                 }
830             }
831 
832             // Ask the Target to find this file on the local system, if possible.
833             // This will search in the list of currently-loaded files, look in the
834             // standard search paths on the system, and on a Mac it will try calling
835             // the DebugSymbols framework with the UUID to find the binary via its
836             // search methods.
837             if (!m_module_sp)
838             {
839                 m_module_sp = target.GetSharedModule (module_spec);
840             }
841 
842             if (IsKernel() && !m_module_sp)
843             {
844                 Stream *s = target.GetDebugger().GetOutputFile().get();
845                 if (s)
846                 {
847                     s->Printf ("WARNING: Unable to locate kernel binary on the debugger system.\n");
848                 }
849             }
850         }
851 
852         // If we managed to find a module, append it to the target's list of images.
853         // If we also have a memory module, require that they have matching UUIDs
854         if (m_module_sp)
855         {
856             bool uuid_match_ok = true;
857             if (m_memory_module_sp)
858             {
859                 if (m_module_sp->GetUUID() != m_memory_module_sp->GetUUID())
860                 {
861                     uuid_match_ok = false;
862                 }
863             }
864             if (uuid_match_ok)
865             {
866                 target.GetImages().AppendIfNeeded(m_module_sp);
867                 if (IsKernel() && target.GetExecutableModulePointer() != m_module_sp.get())
868                 {
869                     target.SetExecutableModule (m_module_sp, false);
870                 }
871             }
872         }
873     }
874 
875     if (!m_module_sp && !IsKernel() && m_uuid.IsValid() && !m_name.empty())
876     {
877         Stream *s = target.GetDebugger().GetOutputFile().get();
878         if (s)
879         {
880             s->Printf ("warning: Can't find binary/dSYM for %s (%s)\n",
881                        m_name.c_str(), m_uuid.GetAsString().c_str());
882         }
883     }
884 
885     static ConstString g_section_name_LINKEDIT ("__LINKEDIT");
886 
887     if (m_memory_module_sp && m_module_sp)
888     {
889         if (m_module_sp->GetUUID() == m_memory_module_sp->GetUUID())
890         {
891             ObjectFile *ondisk_object_file = m_module_sp->GetObjectFile();
892             ObjectFile *memory_object_file = m_memory_module_sp->GetObjectFile();
893 
894             if (memory_object_file && ondisk_object_file)
895             {
896                 // The memory_module for kexts may have an invalid __LINKEDIT seg; skip it.
897                 const bool ignore_linkedit = !IsKernel ();
898 
899                 SectionList *ondisk_section_list = ondisk_object_file->GetSectionList ();
900                 SectionList *memory_section_list = memory_object_file->GetSectionList ();
901                 if (memory_section_list && ondisk_section_list)
902                 {
903                     const uint32_t num_ondisk_sections = ondisk_section_list->GetSize();
904                     // There may be CTF sections in the memory image so we can't
905                     // always just compare the number of sections (which are actually
906                     // segments in mach-o parlance)
907                     uint32_t sect_idx = 0;
908 
909                     // Use the memory_module's addresses for each section to set the
910                     // file module's load address as appropriate.  We don't want to use
911                     // a single slide value for the entire kext - different segments may
912                     // be slid different amounts by the kext loader.
913 
914                     uint32_t num_sections_loaded = 0;
915                     for (sect_idx=0; sect_idx<num_ondisk_sections; ++sect_idx)
916                     {
917                         SectionSP ondisk_section_sp(ondisk_section_list->GetSectionAtIndex(sect_idx));
918                         if (ondisk_section_sp)
919                         {
920                             // Don't ever load __LINKEDIT as it may or may not be actually
921                             // mapped into memory and there is no current way to tell.
922                             // I filed rdar://problem/12851706 to track being able to tell
923                             // if the __LINKEDIT is actually mapped, but until then, we need
924                             // to not load the __LINKEDIT
925                             if (ignore_linkedit && ondisk_section_sp->GetName() == g_section_name_LINKEDIT)
926                                 continue;
927 
928                             const Section *memory_section = memory_section_list->FindSectionByName(ondisk_section_sp->GetName()).get();
929                             if (memory_section)
930                             {
931                                 target.SetSectionLoadAddress (ondisk_section_sp, memory_section->GetFileAddress());
932                                 ++num_sections_loaded;
933                             }
934                         }
935                     }
936                     if (num_sections_loaded > 0)
937                         m_load_process_stop_id = process->GetStopID();
938                     else
939                         m_module_sp.reset(); // No sections were loaded
940                 }
941                 else
942                     m_module_sp.reset(); // One or both section lists
943             }
944             else
945                 m_module_sp.reset(); // One or both object files missing
946         }
947         else
948             m_module_sp.reset(); // UUID mismatch
949     }
950 
951     bool is_loaded = IsLoaded();
952 
953     if (is_loaded && m_module_sp && IsKernel())
954     {
955         Stream *s = target.GetDebugger().GetOutputFile().get();
956         if (s)
957         {
958             ObjectFile *kernel_object_file = m_module_sp->GetObjectFile();
959             if (kernel_object_file)
960             {
961                 addr_t file_address = kernel_object_file->GetHeaderAddress().GetFileAddress();
962                 if (m_load_address != LLDB_INVALID_ADDRESS && file_address != LLDB_INVALID_ADDRESS)
963                 {
964                     s->Printf ("Kernel slid 0x%" PRIx64 " in memory.\n", m_load_address - file_address);
965                 }
966             }
967             {
968                 s->Printf ("Loaded kernel file %s\n",
969                            m_module_sp->GetFileSpec().GetPath().c_str());
970             }
971             s->Flush ();
972         }
973     }
974     return is_loaded;
975 }
976 
977 uint32_t
978 DynamicLoaderDarwinKernel::KextImageInfo::GetAddressByteSize ()
979 {
980     if (m_memory_module_sp)
981         return m_memory_module_sp->GetArchitecture().GetAddressByteSize();
982     if (m_module_sp)
983         return m_module_sp->GetArchitecture().GetAddressByteSize();
984     return 0;
985 }
986 
987 lldb::ByteOrder
988 DynamicLoaderDarwinKernel::KextImageInfo::GetByteOrder()
989 {
990     if (m_memory_module_sp)
991         return m_memory_module_sp->GetArchitecture().GetByteOrder();
992     if (m_module_sp)
993         return m_module_sp->GetArchitecture().GetByteOrder();
994     return lldb::endian::InlHostByteOrder();
995 }
996 
997 lldb_private::ArchSpec
998 DynamicLoaderDarwinKernel::KextImageInfo::GetArchitecture () const
999 {
1000     if (m_memory_module_sp)
1001         return m_memory_module_sp->GetArchitecture();
1002     if (m_module_sp)
1003         return m_module_sp->GetArchitecture();
1004     return lldb_private::ArchSpec ();
1005 }
1006 
1007 
1008 //----------------------------------------------------------------------
1009 // Load the kernel module and initialize the "m_kernel" member. Return
1010 // true _only_ if the kernel is loaded the first time through (subsequent
1011 // calls to this function should return false after the kernel has been
1012 // already loaded).
1013 //----------------------------------------------------------------------
1014 void
1015 DynamicLoaderDarwinKernel::LoadKernelModuleIfNeeded()
1016 {
1017     if (!m_kext_summary_header_ptr_addr.IsValid())
1018     {
1019         m_kernel.Clear();
1020         m_kernel.SetModule (m_process->GetTarget().GetExecutableModule());
1021         m_kernel.SetIsKernel(true);
1022 
1023         ConstString kernel_name("mach_kernel");
1024         if (m_kernel.GetModule().get()
1025             && m_kernel.GetModule()->GetObjectFile()
1026             && !m_kernel.GetModule()->GetObjectFile()->GetFileSpec().GetFilename().IsEmpty())
1027         {
1028             kernel_name = m_kernel.GetModule()->GetObjectFile()->GetFileSpec().GetFilename();
1029         }
1030         m_kernel.SetName (kernel_name.AsCString());
1031 
1032         if (m_kernel.GetLoadAddress() == LLDB_INVALID_ADDRESS)
1033         {
1034             m_kernel.SetLoadAddress(m_kernel_load_address);
1035             if (m_kernel.GetLoadAddress() == LLDB_INVALID_ADDRESS && m_kernel.GetModule())
1036             {
1037                 // We didn't get a hint from the process, so we will
1038                 // try the kernel at the address that it exists at in
1039                 // the file if we have one
1040                 ObjectFile *kernel_object_file = m_kernel.GetModule()->GetObjectFile();
1041                 if (kernel_object_file)
1042                 {
1043                     addr_t load_address = kernel_object_file->GetHeaderAddress().GetLoadAddress(&m_process->GetTarget());
1044                     addr_t file_address = kernel_object_file->GetHeaderAddress().GetFileAddress();
1045                     if (load_address != LLDB_INVALID_ADDRESS && load_address != 0)
1046                     {
1047                         m_kernel.SetLoadAddress (load_address);
1048                         if (load_address != file_address)
1049                         {
1050                             // Don't accidentally relocate the kernel to the File address --
1051                             // the Load address has already been set to its actual in-memory address.
1052                             // Mark it as IsLoaded.
1053                             m_kernel.SetProcessStopId (m_process->GetStopID());
1054                         }
1055                     }
1056                     else
1057                     {
1058                         m_kernel.SetLoadAddress(file_address);
1059                     }
1060                 }
1061             }
1062         }
1063 
1064         if (m_kernel.GetLoadAddress() != LLDB_INVALID_ADDRESS)
1065         {
1066             if (!m_kernel.LoadImageUsingMemoryModule (m_process))
1067             {
1068                 m_kernel.LoadImageAtFileAddress (m_process);
1069             }
1070         }
1071 
1072         if (m_kernel.IsLoaded() && m_kernel.GetModule())
1073         {
1074             static ConstString kext_summary_symbol ("gLoadedKextSummaries");
1075             const Symbol *symbol = m_kernel.GetModule()->FindFirstSymbolWithNameAndType (kext_summary_symbol, eSymbolTypeData);
1076             if (symbol)
1077             {
1078                 m_kext_summary_header_ptr_addr = symbol->GetAddress();
1079                 // Update all image infos
1080                 ReadAllKextSummaries ();
1081             }
1082         }
1083         else
1084         {
1085             m_kernel.Clear();
1086         }
1087     }
1088 }
1089 
1090 //----------------------------------------------------------------------
1091 // Static callback function that gets called when our DYLD notification
1092 // breakpoint gets hit. We update all of our image infos and then
1093 // let our super class DynamicLoader class decide if we should stop
1094 // or not (based on global preference).
1095 //----------------------------------------------------------------------
1096 bool
1097 DynamicLoaderDarwinKernel::BreakpointHitCallback (void *baton,
1098                                                   StoppointCallbackContext *context,
1099                                                   user_id_t break_id,
1100                                                   user_id_t break_loc_id)
1101 {
1102     return static_cast<DynamicLoaderDarwinKernel*>(baton)->BreakpointHit (context, break_id, break_loc_id);
1103 }
1104 
1105 bool
1106 DynamicLoaderDarwinKernel::BreakpointHit (StoppointCallbackContext *context,
1107                                           user_id_t break_id,
1108                                           user_id_t break_loc_id)
1109 {
1110     Log *log(GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
1111     if (log)
1112         log->Printf ("DynamicLoaderDarwinKernel::BreakpointHit (...)\n");
1113 
1114     ReadAllKextSummaries ();
1115 
1116     if (log)
1117         PutToLog(log);
1118 
1119     return GetStopWhenImagesChange();
1120 }
1121 
1122 
1123 bool
1124 DynamicLoaderDarwinKernel::ReadKextSummaryHeader ()
1125 {
1126     Mutex::Locker locker(m_mutex);
1127 
1128     // the all image infos is already valid for this process stop ID
1129 
1130     if (m_kext_summary_header_ptr_addr.IsValid())
1131     {
1132         const uint32_t addr_size = m_kernel.GetAddressByteSize ();
1133         const ByteOrder byte_order = m_kernel.GetByteOrder();
1134         Error error;
1135         // Read enough bytes for a "OSKextLoadedKextSummaryHeader" structure
1136         // which is currently 4 uint32_t and a pointer.
1137         uint8_t buf[24];
1138         DataExtractor data (buf, sizeof(buf), byte_order, addr_size);
1139         const size_t count = 4 * sizeof(uint32_t) + addr_size;
1140         const bool prefer_file_cache = false;
1141         if (m_process->GetTarget().ReadPointerFromMemory (m_kext_summary_header_ptr_addr,
1142                                                           prefer_file_cache,
1143                                                           error,
1144                                                           m_kext_summary_header_addr))
1145         {
1146             // We got a valid address for our kext summary header and make sure it isn't NULL
1147             if (m_kext_summary_header_addr.IsValid() &&
1148                 m_kext_summary_header_addr.GetFileAddress() != 0)
1149             {
1150                 const size_t bytes_read = m_process->GetTarget().ReadMemory (m_kext_summary_header_addr, prefer_file_cache, buf, count, error);
1151                 if (bytes_read == count)
1152                 {
1153                     lldb::offset_t offset = 0;
1154                     m_kext_summary_header.version = data.GetU32(&offset);
1155                     if (m_kext_summary_header.version > 128)
1156                     {
1157                         Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1158                         s->Printf ("WARNING: Unable to read kext summary header, got improbable version number %u\n", m_kext_summary_header.version);
1159                         // If we get an improbably large version number, we're probably getting bad memory.
1160                         m_kext_summary_header_addr.Clear();
1161                         return false;
1162                     }
1163                     if (m_kext_summary_header.version >= 2)
1164                     {
1165                         m_kext_summary_header.entry_size = data.GetU32(&offset);
1166                         if (m_kext_summary_header.entry_size > 4096)
1167                         {
1168                             // If we get an improbably large entry_size, we're probably getting bad memory.
1169                             Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1170                             s->Printf ("WARNING: Unable to read kext summary header, got improbable entry_size %u\n", m_kext_summary_header.entry_size);
1171                             m_kext_summary_header_addr.Clear();
1172                             return false;
1173                         }
1174                     }
1175                     else
1176                     {
1177                         // Versions less than 2 didn't have an entry size, it was hard coded
1178                         m_kext_summary_header.entry_size = KERNEL_MODULE_ENTRY_SIZE_VERSION_1;
1179                     }
1180                     m_kext_summary_header.entry_count = data.GetU32(&offset);
1181                     if (m_kext_summary_header.entry_count > 10000)
1182                     {
1183                         // If we get an improbably large number of kexts, we're probably getting bad memory.
1184                         Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1185                         s->Printf ("WARNING: Unable to read kext summary header, got improbable number of kexts %u\n", m_kext_summary_header.entry_count);
1186                         m_kext_summary_header_addr.Clear();
1187                         return false;
1188                     }
1189                     return true;
1190                 }
1191             }
1192         }
1193     }
1194     m_kext_summary_header_addr.Clear();
1195     return false;
1196 }
1197 
1198 // We've either (a) just attached to a new kernel, or (b) the kexts-changed breakpoint was hit
1199 // and we need to figure out what kexts have been added or removed.
1200 // Read the kext summaries from the inferior kernel memory, compare them against the
1201 // m_known_kexts vector and update the m_known_kexts vector as needed to keep in sync with the
1202 // inferior.
1203 
1204 bool
1205 DynamicLoaderDarwinKernel::ParseKextSummaries (const Address &kext_summary_addr, uint32_t count)
1206 {
1207     KextImageInfo::collection kext_summaries;
1208     Log *log(GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
1209     if (log)
1210         log->Printf ("Kexts-changed breakpoint hit, there are %d kexts currently.\n", count);
1211 
1212     Mutex::Locker locker(m_mutex);
1213 
1214     if (!ReadKextSummaries (kext_summary_addr, count, kext_summaries))
1215         return false;
1216 
1217     // read the plugin.dynamic-loader.darwin-kernel.load-kexts setting -- if the user requested no
1218     // kext loading, don't print any messages about kexts & don't try to read them.
1219     const bool load_kexts = GetGlobalProperties()->GetLoadKexts();
1220 
1221     // By default, all kexts we've loaded in the past are marked as "remove" and all of the kexts
1222     // we just found out about from ReadKextSummaries are marked as "add".
1223     std::vector<bool> to_be_removed(m_known_kexts.size(), true);
1224     std::vector<bool> to_be_added(count, true);
1225 
1226     int number_of_new_kexts_being_added = 0;
1227     int number_of_old_kexts_being_removed = m_known_kexts.size();
1228 
1229     const uint32_t new_kexts_size = kext_summaries.size();
1230     const uint32_t old_kexts_size = m_known_kexts.size();
1231 
1232     // The m_known_kexts vector may have entries that have been Cleared,
1233     // or are a kernel.
1234     for (uint32_t old_kext = 0; old_kext < old_kexts_size; old_kext++)
1235     {
1236         bool ignore = false;
1237         KextImageInfo &image_info = m_known_kexts[old_kext];
1238         if (image_info.IsKernel())
1239         {
1240             ignore = true;
1241         }
1242         else if (image_info.GetLoadAddress() == LLDB_INVALID_ADDRESS && !image_info.GetModule())
1243         {
1244             ignore = true;
1245         }
1246 
1247         if (ignore)
1248         {
1249             number_of_old_kexts_being_removed--;
1250             to_be_removed[old_kext] = false;
1251         }
1252     }
1253 
1254     // Scan over the list of kexts we just read from the kernel, note those that
1255     // need to be added and those already loaded.
1256     for (uint32_t new_kext = 0; new_kext < new_kexts_size; new_kext++)
1257     {
1258         bool add_this_one = true;
1259         for (uint32_t old_kext = 0; old_kext < old_kexts_size; old_kext++)
1260         {
1261             if (m_known_kexts[old_kext] == kext_summaries[new_kext])
1262             {
1263                 // We already have this kext, don't re-load it.
1264                 to_be_added[new_kext] = false;
1265                 // This kext is still present, do not remove it.
1266                 to_be_removed[old_kext] = false;
1267 
1268                 number_of_old_kexts_being_removed--;
1269                 add_this_one = false;
1270                 break;
1271             }
1272         }
1273         if (add_this_one)
1274         {
1275             number_of_new_kexts_being_added++;
1276         }
1277     }
1278 
1279     if (number_of_new_kexts_being_added == 0 && number_of_old_kexts_being_removed == 0)
1280         return true;
1281 
1282     Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1283     if (s && load_kexts)
1284     {
1285         if (number_of_new_kexts_being_added > 0 && number_of_old_kexts_being_removed > 0)
1286         {
1287             s->Printf ("Loading %d kext modules and unloading %d kext modules ", number_of_new_kexts_being_added, number_of_old_kexts_being_removed);
1288         }
1289         else if (number_of_new_kexts_being_added > 0)
1290         {
1291             s->Printf ("Loading %d kext modules ", number_of_new_kexts_being_added);
1292         }
1293         else if (number_of_old_kexts_being_removed > 0)
1294         {
1295             s->Printf ("Unloading %d kext modules ", number_of_old_kexts_being_removed);
1296         }
1297     }
1298 
1299     if (log)
1300     {
1301         if (load_kexts)
1302         {
1303             log->Printf ("DynamicLoaderDarwinKernel::ParseKextSummaries: %d kexts added, %d kexts removed", number_of_new_kexts_being_added, number_of_old_kexts_being_removed);
1304         }
1305         else
1306         {
1307             log->Printf ("DynamicLoaderDarwinKernel::ParseKextSummaries kext loading is disabled, else would have %d kexts added, %d kexts removed", number_of_new_kexts_being_added, number_of_old_kexts_being_removed);
1308         }
1309     }
1310 
1311 
1312     if (number_of_new_kexts_being_added > 0)
1313     {
1314         ModuleList loaded_module_list;
1315 
1316         const uint32_t num_of_new_kexts = kext_summaries.size();
1317         for (uint32_t new_kext = 0; new_kext < num_of_new_kexts; new_kext++)
1318         {
1319             if (to_be_added[new_kext] == true)
1320             {
1321                 KextImageInfo &image_info = kext_summaries[new_kext];
1322                 if (load_kexts)
1323                 {
1324                     if (!image_info.LoadImageUsingMemoryModule (m_process))
1325                     {
1326                         image_info.LoadImageAtFileAddress (m_process);
1327                     }
1328                 }
1329 
1330                 m_known_kexts.push_back(image_info);
1331 
1332                 if (image_info.GetModule() && m_process->GetStopID() == image_info.GetProcessStopId())
1333                     loaded_module_list.AppendIfNeeded (image_info.GetModule());
1334 
1335                 if (s && load_kexts)
1336                     s->Printf (".");
1337 
1338                 if (log)
1339                     kext_summaries[new_kext].PutToLog (log);
1340             }
1341         }
1342         m_process->GetTarget().ModulesDidLoad (loaded_module_list);
1343     }
1344 
1345     if (number_of_old_kexts_being_removed > 0)
1346     {
1347         ModuleList loaded_module_list;
1348         const uint32_t num_of_old_kexts = m_known_kexts.size();
1349         for (uint32_t old_kext = 0; old_kext < num_of_old_kexts; old_kext++)
1350         {
1351             ModuleList unloaded_module_list;
1352             if (to_be_removed[old_kext])
1353             {
1354                 KextImageInfo &image_info = m_known_kexts[old_kext];
1355                 // You can't unload the kernel.
1356                 if (!image_info.IsKernel())
1357                 {
1358                     if (image_info.GetModule())
1359                     {
1360                         unloaded_module_list.AppendIfNeeded (image_info.GetModule());
1361                     }
1362                     if (s)
1363                         s->Printf (".");
1364                     image_info.Clear();
1365                     // should pull it out of the KextImageInfos vector but that would mutate the list and invalidate
1366                     // the to_be_removed bool vector; leaving it in place once Cleared() is relatively harmless.
1367                 }
1368             }
1369             m_process->GetTarget().ModulesDidUnload (unloaded_module_list, false);
1370         }
1371     }
1372 
1373     if (s && load_kexts)
1374     {
1375         s->Printf (" done.\n");
1376         s->Flush ();
1377     }
1378 
1379     return true;
1380 }
1381 
1382 uint32_t
1383 DynamicLoaderDarwinKernel::ReadKextSummaries (const Address &kext_summary_addr,
1384                                               uint32_t image_infos_count,
1385                                               KextImageInfo::collection &image_infos)
1386 {
1387     const ByteOrder endian = m_kernel.GetByteOrder();
1388     const uint32_t addr_size = m_kernel.GetAddressByteSize();
1389 
1390     image_infos.resize(image_infos_count);
1391     const size_t count = image_infos.size() * m_kext_summary_header.entry_size;
1392     DataBufferHeap data(count, 0);
1393     Error error;
1394 
1395     const bool prefer_file_cache = false;
1396     const size_t bytes_read = m_process->GetTarget().ReadMemory (kext_summary_addr,
1397                                                                  prefer_file_cache,
1398                                                                  data.GetBytes(),
1399                                                                  data.GetByteSize(),
1400                                                                  error);
1401     if (bytes_read == count)
1402     {
1403 
1404         DataExtractor extractor (data.GetBytes(), data.GetByteSize(), endian, addr_size);
1405         uint32_t i=0;
1406         for (uint32_t kext_summary_offset = 0;
1407              i < image_infos.size() && extractor.ValidOffsetForDataOfSize(kext_summary_offset, m_kext_summary_header.entry_size);
1408              ++i, kext_summary_offset += m_kext_summary_header.entry_size)
1409         {
1410             lldb::offset_t offset = kext_summary_offset;
1411             const void *name_data = extractor.GetData(&offset, KERNEL_MODULE_MAX_NAME);
1412             if (name_data == NULL)
1413                 break;
1414             image_infos[i].SetName ((const char *) name_data);
1415             UUID uuid (extractor.GetData (&offset, 16), 16);
1416             image_infos[i].SetUUID (uuid);
1417             image_infos[i].SetLoadAddress (extractor.GetU64(&offset));
1418             image_infos[i].SetSize (extractor.GetU64(&offset));
1419         }
1420         if (i < image_infos.size())
1421             image_infos.resize(i);
1422     }
1423     else
1424     {
1425         image_infos.clear();
1426     }
1427     return image_infos.size();
1428 }
1429 
1430 bool
1431 DynamicLoaderDarwinKernel::ReadAllKextSummaries ()
1432 {
1433     Mutex::Locker locker(m_mutex);
1434 
1435     if (ReadKextSummaryHeader ())
1436     {
1437         if (m_kext_summary_header.entry_count > 0 && m_kext_summary_header_addr.IsValid())
1438         {
1439             Address summary_addr (m_kext_summary_header_addr);
1440             summary_addr.Slide(m_kext_summary_header.GetSize());
1441             if (!ParseKextSummaries (summary_addr, m_kext_summary_header.entry_count))
1442             {
1443                 m_known_kexts.clear();
1444             }
1445             return true;
1446         }
1447     }
1448     return false;
1449 }
1450 
1451 //----------------------------------------------------------------------
1452 // Dump an image info structure to the file handle provided.
1453 //----------------------------------------------------------------------
1454 void
1455 DynamicLoaderDarwinKernel::KextImageInfo::PutToLog (Log *log) const
1456 {
1457     if (log == NULL)
1458         return;
1459     const uint8_t *u = (uint8_t *) m_uuid.GetBytes();
1460 
1461     if (m_load_address == LLDB_INVALID_ADDRESS)
1462     {
1463         if (u)
1464         {
1465             log->Printf("\tuuid=%2.2X%2.2X%2.2X%2.2X-%2.2X%2.2X-%2.2X%2.2X-%2.2X%2.2X-%2.2X%2.2X%2.2X%2.2X%2.2X%2.2X name=\"%s\" (UNLOADED)",
1466                         u[ 0], u[ 1], u[ 2], u[ 3],
1467                         u[ 4], u[ 5], u[ 6], u[ 7],
1468                         u[ 8], u[ 9], u[10], u[11],
1469                         u[12], u[13], u[14], u[15],
1470                         m_name.c_str());
1471         }
1472         else
1473             log->Printf("\tname=\"%s\" (UNLOADED)", m_name.c_str());
1474     }
1475     else
1476     {
1477         if (u)
1478         {
1479             log->Printf("\taddr=0x%16.16" PRIx64 " size=0x%16.16" PRIx64 " uuid=%2.2X%2.2X%2.2X%2.2X-%2.2X%2.2X-%2.2X%2.2X-%2.2X%2.2X-%2.2X%2.2X%2.2X%2.2X%2.2X%2.2X name=\"%s\"",
1480                         m_load_address, m_size,
1481                         u[ 0], u[ 1], u[ 2], u[ 3], u[ 4], u[ 5], u[ 6], u[ 7],
1482                         u[ 8], u[ 9], u[10], u[11], u[12], u[13], u[14], u[15],
1483                         m_name.c_str());
1484         }
1485         else
1486         {
1487             log->Printf("\t[0x%16.16" PRIx64 " - 0x%16.16" PRIx64 ") name=\"%s\"",
1488                         m_load_address, m_load_address+m_size, m_name.c_str());
1489         }
1490     }
1491 }
1492 
1493 //----------------------------------------------------------------------
1494 // Dump the _dyld_all_image_infos members and all current image infos
1495 // that we have parsed to the file handle provided.
1496 //----------------------------------------------------------------------
1497 void
1498 DynamicLoaderDarwinKernel::PutToLog(Log *log) const
1499 {
1500     if (log == NULL)
1501         return;
1502 
1503     Mutex::Locker locker(m_mutex);
1504     log->Printf("gLoadedKextSummaries = 0x%16.16" PRIx64 " { version=%u, entry_size=%u, entry_count=%u }",
1505                 m_kext_summary_header_addr.GetFileAddress(),
1506                 m_kext_summary_header.version,
1507                 m_kext_summary_header.entry_size,
1508                 m_kext_summary_header.entry_count);
1509 
1510     size_t i;
1511     const size_t count = m_known_kexts.size();
1512     if (count > 0)
1513     {
1514         log->PutCString("Loaded:");
1515         for (i = 0; i<count; i++)
1516             m_known_kexts[i].PutToLog(log);
1517     }
1518 }
1519 
1520 void
1521 DynamicLoaderDarwinKernel::PrivateInitialize(Process *process)
1522 {
1523     DEBUG_PRINTF("DynamicLoaderDarwinKernel::%s() process state = %s\n", __FUNCTION__, StateAsCString(m_process->GetState()));
1524     Clear(true);
1525     m_process = process;
1526 }
1527 
1528 void
1529 DynamicLoaderDarwinKernel::SetNotificationBreakpointIfNeeded ()
1530 {
1531     if (m_break_id == LLDB_INVALID_BREAK_ID && m_kernel.GetModule())
1532     {
1533         DEBUG_PRINTF("DynamicLoaderDarwinKernel::%s() process state = %s\n", __FUNCTION__, StateAsCString(m_process->GetState()));
1534 
1535 
1536         const bool internal_bp = true;
1537         const bool hardware = false;
1538         const LazyBool skip_prologue = eLazyBoolNo;
1539         FileSpecList module_spec_list;
1540         module_spec_list.Append (m_kernel.GetModule()->GetFileSpec());
1541         Breakpoint *bp = m_process->GetTarget().CreateBreakpoint (&module_spec_list,
1542                                                                   NULL,
1543                                                                   "OSKextLoadedKextSummariesUpdated",
1544                                                                   eFunctionNameTypeFull,
1545                                                                   skip_prologue,
1546                                                                   internal_bp,
1547                                                                   hardware).get();
1548 
1549         bp->SetCallback (DynamicLoaderDarwinKernel::BreakpointHitCallback, this, true);
1550         m_break_id = bp->GetID();
1551     }
1552 }
1553 
1554 //----------------------------------------------------------------------
1555 // Member function that gets called when the process state changes.
1556 //----------------------------------------------------------------------
1557 void
1558 DynamicLoaderDarwinKernel::PrivateProcessStateChanged (Process *process, StateType state)
1559 {
1560     DEBUG_PRINTF("DynamicLoaderDarwinKernel::%s(%s)\n", __FUNCTION__, StateAsCString(state));
1561     switch (state)
1562     {
1563     case eStateConnected:
1564     case eStateAttaching:
1565     case eStateLaunching:
1566     case eStateInvalid:
1567     case eStateUnloaded:
1568     case eStateExited:
1569     case eStateDetached:
1570         Clear(false);
1571         break;
1572 
1573     case eStateStopped:
1574         UpdateIfNeeded();
1575         break;
1576 
1577     case eStateRunning:
1578     case eStateStepping:
1579     case eStateCrashed:
1580     case eStateSuspended:
1581         break;
1582     }
1583 }
1584 
1585 ThreadPlanSP
1586 DynamicLoaderDarwinKernel::GetStepThroughTrampolinePlan (Thread &thread, bool stop_others)
1587 {
1588     ThreadPlanSP thread_plan_sp;
1589     Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1590     if (log)
1591         log->Printf ("Could not find symbol for step through.");
1592     return thread_plan_sp;
1593 }
1594 
1595 Error
1596 DynamicLoaderDarwinKernel::CanLoadImage ()
1597 {
1598     Error error;
1599     error.SetErrorString("always unsafe to load or unload shared libraries in the darwin kernel");
1600     return error;
1601 }
1602 
1603 void
1604 DynamicLoaderDarwinKernel::Initialize()
1605 {
1606     PluginManager::RegisterPlugin (GetPluginNameStatic(),
1607                                    GetPluginDescriptionStatic(),
1608                                    CreateInstance,
1609                                    DebuggerInitialize);
1610 }
1611 
1612 void
1613 DynamicLoaderDarwinKernel::Terminate()
1614 {
1615     PluginManager::UnregisterPlugin (CreateInstance);
1616 }
1617 
1618 void
1619 DynamicLoaderDarwinKernel::DebuggerInitialize (lldb_private::Debugger &debugger)
1620 {
1621     if (!PluginManager::GetSettingForDynamicLoaderPlugin (debugger, DynamicLoaderDarwinKernelProperties::GetSettingName()))
1622     {
1623         const bool is_global_setting = true;
1624         PluginManager::CreateSettingForDynamicLoaderPlugin (debugger,
1625                                                             GetGlobalProperties()->GetValueProperties(),
1626                                                             ConstString ("Properties for the DynamicLoaderDarwinKernel plug-in."),
1627                                                             is_global_setting);
1628     }
1629 }
1630 
1631 lldb_private::ConstString
1632 DynamicLoaderDarwinKernel::GetPluginNameStatic()
1633 {
1634     static ConstString g_name("darwin-kernel");
1635     return g_name;
1636 }
1637 
1638 const char *
1639 DynamicLoaderDarwinKernel::GetPluginDescriptionStatic()
1640 {
1641     return "Dynamic loader plug-in that watches for shared library loads/unloads in the MacOSX kernel.";
1642 }
1643 
1644 
1645 //------------------------------------------------------------------
1646 // PluginInterface protocol
1647 //------------------------------------------------------------------
1648 lldb_private::ConstString
1649 DynamicLoaderDarwinKernel::GetPluginName()
1650 {
1651     return GetPluginNameStatic();
1652 }
1653 
1654 uint32_t
1655 DynamicLoaderDarwinKernel::GetPluginVersion()
1656 {
1657     return 1;
1658 }
1659 
1660 lldb::ByteOrder
1661 DynamicLoaderDarwinKernel::GetByteOrderFromMagic (uint32_t magic)
1662 {
1663     switch (magic)
1664     {
1665         case llvm::MachO::MH_MAGIC:
1666         case llvm::MachO::MH_MAGIC_64:
1667             return lldb::endian::InlHostByteOrder();
1668 
1669         case llvm::MachO::MH_CIGAM:
1670         case llvm::MachO::MH_CIGAM_64:
1671             if (lldb::endian::InlHostByteOrder() == lldb::eByteOrderBig)
1672                 return lldb::eByteOrderLittle;
1673             else
1674                 return lldb::eByteOrderBig;
1675 
1676         default:
1677             break;
1678     }
1679     return lldb::eByteOrderInvalid;
1680 }
1681 
1682