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/Utility/SafeMachO.h"
11 
12 #include "lldb/Breakpoint/StoppointCallbackContext.h"
13 #include "lldb/Core/DataBuffer.h"
14 #include "lldb/Core/DataBufferHeap.h"
15 #include "lldb/Core/Debugger.h"
16 #include "lldb/Core/Log.h"
17 #include "lldb/Core/Module.h"
18 #include "lldb/Core/ModuleSpec.h"
19 #include "lldb/Core/PluginManager.h"
20 #include "lldb/Core/Section.h"
21 #include "lldb/Core/State.h"
22 #include "lldb/Core/StreamFile.h"
23 #include "lldb/Host/Symbols.h"
24 #include "lldb/Interpreter/OptionValueProperties.h"
25 #include "lldb/Symbol/ObjectFile.h"
26 #include "lldb/Target/RegisterContext.h"
27 #include "lldb/Target/StackFrame.h"
28 #include "lldb/Target/Target.h"
29 #include "lldb/Target/Thread.h"
30 #include "lldb/Target/ThreadPlanRunToAddress.h"
31 #include "Plugins/Platform/MacOSX/PlatformDarwinKernel.h"
32 
33 #include "DynamicLoaderDarwinKernel.h"
34 
35 //#define ENABLE_DEBUG_PRINTF // COMMENT THIS LINE OUT PRIOR TO CHECKIN
36 #ifdef ENABLE_DEBUG_PRINTF
37 #include <stdio.h>
38 #define DEBUG_PRINTF(fmt, ...) printf(fmt, ## __VA_ARGS__)
39 #else
40 #define DEBUG_PRINTF(fmt, ...)
41 #endif
42 
43 using namespace lldb;
44 using namespace lldb_private;
45 
46 // Progressively greater amounts of scanning we will allow
47 // For some targets very early in startup, we can't do any random reads of memory or we can crash the device
48 // so a setting is needed that can completely disable the KASLR scans.
49 
50 enum KASLRScanType
51 {
52     eKASLRScanNone = 0,         // No reading into the inferior at all
53     eKASLRScanLowgloAddresses,  // Check one word of memory for a possible kernel addr, then see if a kernel is there
54     eKASLRScanNearPC,           // Scan backwards from the current $pc looking for kernel; checking at 96 locations total
55     eKASLRScanExhaustiveScan    // Scan through the entire possible kernel address range looking for a kernel
56 };
57 
58 OptionEnumValueElement
59 g_kaslr_kernel_scan_enum_values[] =
60 {
61     { eKASLRScanNone,            "none",            "Do not read memory looking for a Darwin kernel when attaching." },
62     { eKASLRScanLowgloAddresses, "basic",           "Check for the Darwin kernel's load addr in the lowglo page (boot-args=debug) only." },
63     { eKASLRScanNearPC,          "fast-scan",       "Scan near the pc value on attach to find the Darwin kernel's load address."},
64     { eKASLRScanExhaustiveScan,  "exhaustive-scan", "Scan through the entire potential address range of Darwin kernel (only on 32-bit targets)."},
65     { 0, NULL, NULL }
66 };
67 
68 static PropertyDefinition
69 g_properties[] =
70 {
71     { "load-kexts" , OptionValue::eTypeBoolean, true, true, NULL, NULL, "Automatically loads kext images when attaching to a kernel." },
72     { "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." },
73     {  NULL        , OptionValue::eTypeInvalid, false, 0  , NULL, NULL, NULL  }
74 };
75 
76 enum {
77     ePropertyLoadKexts,
78     ePropertyScanType
79 };
80 
81 class DynamicLoaderDarwinKernelProperties : public Properties
82 {
83 public:
84 
85     static ConstString &
86     GetSettingName ()
87     {
88         static ConstString g_setting_name("darwin-kernel");
89         return g_setting_name;
90     }
91 
92     DynamicLoaderDarwinKernelProperties() :
93         Properties ()
94     {
95         m_collection_sp.reset (new OptionValueProperties(GetSettingName()));
96         m_collection_sp->Initialize(g_properties);
97     }
98 
99     virtual
100     ~DynamicLoaderDarwinKernelProperties()
101     {
102     }
103 
104     bool
105     GetLoadKexts() const
106     {
107         const uint32_t idx = ePropertyLoadKexts;
108         return m_collection_sp->GetPropertyAtIndexAsBoolean (NULL, idx, g_properties[idx].default_uint_value != 0);
109     }
110 
111     KASLRScanType
112     GetScanType() const
113     {
114         const uint32_t idx = ePropertyScanType;
115         return (KASLRScanType) m_collection_sp->GetPropertyAtIndexAsEnumeration (NULL, idx, g_properties[idx].default_uint_value);
116     }
117 
118 
119 };
120 
121 typedef std::shared_ptr<DynamicLoaderDarwinKernelProperties> DynamicLoaderDarwinKernelPropertiesSP;
122 
123 static const DynamicLoaderDarwinKernelPropertiesSP &
124 GetGlobalProperties()
125 {
126     static DynamicLoaderDarwinKernelPropertiesSP g_settings_sp;
127     if (!g_settings_sp)
128         g_settings_sp.reset (new DynamicLoaderDarwinKernelProperties ());
129     return g_settings_sp;
130 }
131 
132 //----------------------------------------------------------------------
133 // Create an instance of this class. This function is filled into
134 // the plugin info class that gets handed out by the plugin factory and
135 // allows the lldb to instantiate an instance of this class.
136 //----------------------------------------------------------------------
137 DynamicLoader *
138 DynamicLoaderDarwinKernel::CreateInstance (Process* process, bool force)
139 {
140     if (!force)
141     {
142         // If the user provided an executable binary and it is not a kernel,
143         // this plugin should not create an instance.
144         Module* exe_module = process->GetTarget().GetExecutableModulePointer();
145         if (exe_module)
146         {
147             ObjectFile *object_file = exe_module->GetObjectFile();
148             if (object_file)
149             {
150                 if (object_file->GetStrata() != ObjectFile::eStrataKernel)
151                 {
152                     return NULL;
153                 }
154             }
155         }
156 
157         // If the target's architecture does not look like an Apple environment,
158         // this plugin should not create an instance.
159         const llvm::Triple &triple_ref = process->GetTarget().GetArchitecture().GetTriple();
160         switch (triple_ref.getOS())
161         {
162             case llvm::Triple::Darwin:
163             case llvm::Triple::MacOSX:
164             case llvm::Triple::IOS:
165                 if (triple_ref.getVendor() != llvm::Triple::Apple)
166                 {
167                    return NULL;
168                 }
169                 break;
170             // If we have triple like armv7-unknown-unknown, we should try looking for a Darwin kernel.
171             case llvm::Triple::UnknownOS:
172                 break;
173             default:
174                 return NULL;
175                 break;
176         }
177     }
178 
179     // At this point if there is an ExecutableModule, it is a kernel and the Target is some variant of an Apple system.
180     // If the Process hasn't provided the kernel load address, we need to look around in memory to find it.
181 
182     addr_t kernel_load_address = SearchForDarwinKernel (process);
183     if (kernel_load_address != LLDB_INVALID_ADDRESS)
184     {
185         process->SetCanRunCode(false);
186         return new DynamicLoaderDarwinKernel (process, kernel_load_address);
187     }
188     return NULL;
189 }
190 
191 lldb::addr_t
192 DynamicLoaderDarwinKernel::SearchForDarwinKernel (Process *process)
193 {
194     addr_t kernel_load_address = process->GetImageInfoAddress();
195     if (kernel_load_address == LLDB_INVALID_ADDRESS)
196     {
197         kernel_load_address = SearchForKernelAtSameLoadAddr (process);
198         if (kernel_load_address == LLDB_INVALID_ADDRESS)
199         {
200             kernel_load_address = SearchForKernelWithDebugHints (process);
201             if (kernel_load_address == LLDB_INVALID_ADDRESS)
202             {
203                 kernel_load_address = SearchForKernelNearPC (process);
204                 if (kernel_load_address == LLDB_INVALID_ADDRESS)
205                 {
206                     kernel_load_address = SearchForKernelViaExhaustiveSearch (process);
207                 }
208             }
209         }
210     }
211     return kernel_load_address;
212 }
213 
214 //----------------------------------------------------------------------
215 // Check if the kernel binary is loaded in memory without a slide.
216 // First verify that the ExecutableModule is a kernel before we proceed.
217 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
218 //----------------------------------------------------------------------
219 lldb::addr_t
220 DynamicLoaderDarwinKernel::SearchForKernelAtSameLoadAddr (Process *process)
221 {
222     Module *exe_module = process->GetTarget().GetExecutableModulePointer();
223     if (exe_module == NULL)
224         return LLDB_INVALID_ADDRESS;
225 
226     ObjectFile *exe_objfile = exe_module->GetObjectFile();
227     if (exe_objfile == NULL)
228         return LLDB_INVALID_ADDRESS;
229 
230     if (exe_objfile->GetType() != ObjectFile::eTypeExecutable || exe_objfile->GetStrata() != ObjectFile::eStrataKernel)
231         return LLDB_INVALID_ADDRESS;
232 
233     if (!exe_objfile->GetHeaderAddress().IsValid())
234         return LLDB_INVALID_ADDRESS;
235 
236     if (CheckForKernelImageAtAddress (exe_objfile->GetHeaderAddress().GetFileAddress(), process) == exe_module->GetUUID())
237         return exe_objfile->GetHeaderAddress().GetFileAddress();
238 
239     return LLDB_INVALID_ADDRESS;
240 }
241 
242 //----------------------------------------------------------------------
243 // If the debug flag is included in the boot-args nvram setting, the kernel's load address
244 // will be noted in the lowglo page at a fixed address
245 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
246 //----------------------------------------------------------------------
247 lldb::addr_t
248 DynamicLoaderDarwinKernel::SearchForKernelWithDebugHints (Process *process)
249 {
250     if (GetGlobalProperties()->GetScanType() == eKASLRScanNone)
251         return LLDB_INVALID_ADDRESS;
252 
253     Error read_err;
254     addr_t addr = LLDB_INVALID_ADDRESS;
255     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
256     {
257         addr = process->ReadUnsignedIntegerFromMemory (0xffffff8000002010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
258         if (CheckForKernelImageAtAddress (addr, process).IsValid())
259         {
260             return addr;
261         }
262         addr = process->ReadUnsignedIntegerFromMemory (0xffffff8000004010ULL, 8, LLDB_INVALID_ADDRESS, read_err);
263         if (CheckForKernelImageAtAddress (addr, process).IsValid())
264         {
265             return addr;
266         }
267     }
268     else
269     {
270         addr = process->ReadUnsignedIntegerFromMemory (0xffff0110, 4, LLDB_INVALID_ADDRESS, read_err);
271         if (CheckForKernelImageAtAddress (addr, process).IsValid())
272         {
273             return addr;
274         }
275     }
276     return LLDB_INVALID_ADDRESS;
277 }
278 
279 //----------------------------------------------------------------------
280 // If the kernel is currently executing when lldb attaches, and we don't have
281 // a better way of finding the kernel's load address, try searching backwards
282 // from the current pc value looking for the kernel's Mach header in memory.
283 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
284 //----------------------------------------------------------------------
285 lldb::addr_t
286 DynamicLoaderDarwinKernel::SearchForKernelNearPC (Process *process)
287 {
288     if (GetGlobalProperties()->GetScanType() == eKASLRScanNone
289         || GetGlobalProperties()->GetScanType() == eKASLRScanLowgloAddresses)
290     {
291         return LLDB_INVALID_ADDRESS;
292     }
293 
294     ThreadSP thread = process->GetThreadList().GetSelectedThread ();
295     if (thread.get() == NULL)
296         return LLDB_INVALID_ADDRESS;
297     addr_t pc = thread->GetRegisterContext ()->GetPC(LLDB_INVALID_ADDRESS);
298 
299     if (pc == LLDB_INVALID_ADDRESS)
300         return LLDB_INVALID_ADDRESS;
301 
302     addr_t kernel_range_low;
303     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
304     {
305         kernel_range_low = 1ULL << 63;
306     }
307     else
308     {
309         kernel_range_low = 1ULL << 31;
310     }
311 
312     // Outside the normal kernel address range, this is probably userland code running right now
313     if (pc < kernel_range_low)
314         return LLDB_INVALID_ADDRESS;
315 
316     // The kernel will load at at one megabyte boundary (0x100000), or at that boundary plus
317     // an offset of one page (0x1000) or two, depending on the device.
318 
319     // Round the current pc down to the nearest one megabyte boundary - the place where we will start searching.
320     addr_t addr = pc & ~0xfffff;
321 
322     int i = 0;
323     while (i < 32 && pc >= kernel_range_low)
324     {
325         if (CheckForKernelImageAtAddress (addr, process).IsValid())
326             return addr;
327         if (CheckForKernelImageAtAddress (addr + 0x1000, process).IsValid())
328             return addr + 0x1000;
329         if (CheckForKernelImageAtAddress (addr + 0x2000, process).IsValid())
330             return addr + 0x2000;
331         if (CheckForKernelImageAtAddress (addr + 0x4000, process).IsValid())
332             return addr + 0x4000;
333         i++;
334         addr -= 0x100000;
335     }
336 
337     return LLDB_INVALID_ADDRESS;
338 }
339 
340 //----------------------------------------------------------------------
341 // Scan through the valid address range for a kernel binary.
342 // This is uselessly slow in 64-bit environments so we don't even try it.
343 // This scan is not enabled by default even for 32-bit targets.
344 // Returns the address of the kernel if one was found, else LLDB_INVALID_ADDRESS.
345 //----------------------------------------------------------------------
346 lldb::addr_t
347 DynamicLoaderDarwinKernel::SearchForKernelViaExhaustiveSearch (Process *process)
348 {
349     if (GetGlobalProperties()->GetScanType() != eKASLRScanExhaustiveScan)
350     {
351         return LLDB_INVALID_ADDRESS;
352     }
353 
354     addr_t kernel_range_low, kernel_range_high;
355     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
356     {
357         kernel_range_low = 1ULL << 63;
358         kernel_range_high = UINT64_MAX;
359     }
360     else
361     {
362         kernel_range_low = 1ULL << 31;
363         kernel_range_high = UINT32_MAX;
364     }
365 
366     // Stepping through memory at one-megabyte resolution looking for a kernel
367     // rarely works (fast enough) with a 64-bit address space -- for now, let's
368     // not even bother.  We may be attaching to something which *isn't* a kernel
369     // and we don't want to spin for minutes on-end looking for a kernel.
370     if (process->GetTarget().GetArchitecture().GetAddressByteSize() == 8)
371         return LLDB_INVALID_ADDRESS;
372 
373     addr_t addr = kernel_range_low;
374 
375     while (addr >= kernel_range_low && addr < kernel_range_high)
376     {
377         if (CheckForKernelImageAtAddress (addr, process).IsValid())
378             return addr;
379         if (CheckForKernelImageAtAddress (addr + 0x1000, process).IsValid())
380             return addr + 0x1000;
381         if (CheckForKernelImageAtAddress (addr + 0x2000, process).IsValid())
382             return addr + 0x2000;
383         if (CheckForKernelImageAtAddress (addr + 0x4000, process).IsValid())
384             return addr + 0x4000;
385         addr += 0x100000;
386     }
387     return LLDB_INVALID_ADDRESS;
388 }
389 
390 //----------------------------------------------------------------------
391 // Given an address in memory, look to see if there is a kernel image at that
392 // address.
393 // Returns a UUID; if a kernel was not found at that address, UUID.IsValid() will be false.
394 //----------------------------------------------------------------------
395 lldb_private::UUID
396 DynamicLoaderDarwinKernel::CheckForKernelImageAtAddress (lldb::addr_t addr, Process *process)
397 {
398     if (addr == LLDB_INVALID_ADDRESS)
399         return UUID();
400 
401     // First try a quick test -- read the first 4 bytes and see if there is a valid Mach-O magic field there
402     // (the first field of the mach_header/mach_header_64 struct).
403 
404     Error read_error;
405     uint64_t result = process->ReadUnsignedIntegerFromMemory (addr, 4, LLDB_INVALID_ADDRESS, read_error);
406     if (result != llvm::MachO::MH_MAGIC_64
407         && result != llvm::MachO::MH_MAGIC
408         && result != llvm::MachO::MH_CIGAM
409         && result != llvm::MachO::MH_CIGAM_64)
410     {
411         return UUID();
412     }
413 
414     // Read the mach header and see whether it looks like a kernel
415     llvm::MachO::mach_header header;
416     if (process->DoReadMemory (addr, &header, sizeof(header), read_error) != sizeof(header))
417         return UUID();
418 
419     if (header.magic == llvm::MachO::MH_CIGAM ||
420         header.magic == llvm::MachO::MH_CIGAM_64)
421     {
422         header.magic        = llvm::ByteSwap_32(header.magic);
423         header.cputype      = llvm::ByteSwap_32(header.cputype);
424         header.cpusubtype   = llvm::ByteSwap_32(header.cpusubtype);
425         header.filetype     = llvm::ByteSwap_32(header.filetype);
426         header.ncmds        = llvm::ByteSwap_32(header.ncmds);
427         header.sizeofcmds   = llvm::ByteSwap_32(header.sizeofcmds);
428         header.flags        = llvm::ByteSwap_32(header.flags);
429     }
430 
431     // A kernel is an executable which does not have the dynamic link object flag set.
432     if (header.filetype == llvm::MachO::MH_EXECUTE
433         && (header.flags & llvm::MachO::MH_DYLDLINK) == 0)
434     {
435         // Create a full module to get the UUID
436         ModuleSP memory_module_sp = process->ReadModuleFromMemory (FileSpec ("temp_mach_kernel", false), addr);
437         if (!memory_module_sp.get())
438             return UUID();
439 
440         ObjectFile *exe_objfile = memory_module_sp->GetObjectFile();
441         if (exe_objfile == NULL)
442             return UUID();
443 
444         if (exe_objfile->GetType() == ObjectFile::eTypeExecutable && exe_objfile->GetStrata() == ObjectFile::eStrataKernel)
445         {
446             ArchSpec kernel_arch (eArchTypeMachO, header.cputype, header.cpusubtype);
447             if (!process->GetTarget().GetArchitecture().IsCompatibleMatch(kernel_arch))
448             {
449                 process->GetTarget().SetArchitecture (kernel_arch);
450             }
451             return memory_module_sp->GetUUID();
452         }
453     }
454 
455     return UUID();
456 }
457 
458 //----------------------------------------------------------------------
459 // Constructor
460 //----------------------------------------------------------------------
461 DynamicLoaderDarwinKernel::DynamicLoaderDarwinKernel (Process* process, lldb::addr_t kernel_addr) :
462     DynamicLoader(process),
463     m_kernel_load_address (kernel_addr),
464     m_kernel(),
465     m_kext_summary_header_ptr_addr (),
466     m_kext_summary_header_addr (),
467     m_kext_summary_header (),
468     m_known_kexts (),
469     m_mutex(Mutex::eMutexTypeRecursive),
470     m_break_id (LLDB_INVALID_BREAK_ID)
471 {
472     Error error;
473     PlatformSP platform_sp(Platform::Create(PlatformDarwinKernel::GetPluginNameStatic(), error));
474     // Only select the darwin-kernel Platform if we've been asked to load kexts.
475     // It can take some time to scan over all of the kext info.plists and that
476     // shouldn't be done if kext loading is explicitly disabled.
477     if (platform_sp.get() && GetGlobalProperties()->GetLoadKexts())
478     {
479         process->GetTarget().SetPlatform (platform_sp);
480     }
481 }
482 
483 //----------------------------------------------------------------------
484 // Destructor
485 //----------------------------------------------------------------------
486 DynamicLoaderDarwinKernel::~DynamicLoaderDarwinKernel()
487 {
488     Clear(true);
489 }
490 
491 void
492 DynamicLoaderDarwinKernel::UpdateIfNeeded()
493 {
494     LoadKernelModuleIfNeeded();
495     SetNotificationBreakpointIfNeeded ();
496 }
497 //------------------------------------------------------------------
498 /// Called after attaching a process.
499 ///
500 /// Allow DynamicLoader plug-ins to execute some code after
501 /// attaching to a process.
502 //------------------------------------------------------------------
503 void
504 DynamicLoaderDarwinKernel::DidAttach ()
505 {
506     PrivateInitialize(m_process);
507     UpdateIfNeeded();
508 }
509 
510 //------------------------------------------------------------------
511 /// Called after attaching a process.
512 ///
513 /// Allow DynamicLoader plug-ins to execute some code after
514 /// attaching to a process.
515 //------------------------------------------------------------------
516 void
517 DynamicLoaderDarwinKernel::DidLaunch ()
518 {
519     PrivateInitialize(m_process);
520     UpdateIfNeeded();
521 }
522 
523 
524 //----------------------------------------------------------------------
525 // Clear out the state of this class.
526 //----------------------------------------------------------------------
527 void
528 DynamicLoaderDarwinKernel::Clear (bool clear_process)
529 {
530     Mutex::Locker locker(m_mutex);
531 
532     if (m_process->IsAlive() && LLDB_BREAK_ID_IS_VALID(m_break_id))
533         m_process->ClearBreakpointSiteByID(m_break_id);
534 
535     if (clear_process)
536         m_process = NULL;
537     m_kernel.Clear();
538     m_known_kexts.clear();
539     m_kext_summary_header_ptr_addr.Clear();
540     m_kext_summary_header_addr.Clear();
541     m_break_id = LLDB_INVALID_BREAK_ID;
542 }
543 
544 
545 bool
546 DynamicLoaderDarwinKernel::KextImageInfo::LoadImageAtFileAddress (Process *process)
547 {
548     if (IsLoaded())
549         return true;
550 
551     if (m_module_sp)
552     {
553         bool changed = false;
554         if (m_module_sp->SetLoadAddress (process->GetTarget(), 0, true, changed))
555             m_load_process_stop_id = process->GetStopID();
556     }
557     return false;
558 }
559 
560 void
561 DynamicLoaderDarwinKernel::KextImageInfo::SetModule (ModuleSP module_sp)
562 {
563     m_module_sp = module_sp;
564     if (module_sp.get() && module_sp->GetObjectFile())
565     {
566         if (module_sp->GetObjectFile()->GetType() == ObjectFile::eTypeExecutable
567             && module_sp->GetObjectFile()->GetStrata() == ObjectFile::eStrataKernel)
568         {
569             m_kernel_image = true;
570         }
571         else
572         {
573             m_kernel_image = false;
574         }
575     }
576 }
577 
578 ModuleSP
579 DynamicLoaderDarwinKernel::KextImageInfo::GetModule ()
580 {
581     return m_module_sp;
582 }
583 
584 void
585 DynamicLoaderDarwinKernel::KextImageInfo::SetLoadAddress (addr_t load_addr)
586 {
587     m_load_address = load_addr;
588 }
589 
590 addr_t
591 DynamicLoaderDarwinKernel::KextImageInfo::GetLoadAddress () const
592 {
593     return m_load_address;
594 }
595 
596 uint64_t
597 DynamicLoaderDarwinKernel::KextImageInfo::GetSize () const
598 {
599     return m_size;
600 }
601 
602 void
603 DynamicLoaderDarwinKernel::KextImageInfo::SetSize (uint64_t size)
604 {
605     m_size = size;
606 }
607 
608 uint32_t
609 DynamicLoaderDarwinKernel::KextImageInfo::GetProcessStopId () const
610 {
611     return m_load_process_stop_id;
612 }
613 
614 void
615 DynamicLoaderDarwinKernel::KextImageInfo::SetProcessStopId (uint32_t stop_id)
616 {
617     m_load_process_stop_id = stop_id;
618 }
619 
620 bool
621 DynamicLoaderDarwinKernel::KextImageInfo::operator== (const KextImageInfo &rhs)
622 {
623     if (m_uuid.IsValid() || rhs.GetUUID().IsValid())
624     {
625         if (m_uuid == rhs.GetUUID())
626         {
627             return true;
628         }
629         return false;
630     }
631 
632     if (m_name == rhs.GetName() && m_load_address == rhs.GetLoadAddress())
633         return true;
634 
635     return false;
636 }
637 
638 void
639 DynamicLoaderDarwinKernel::KextImageInfo::SetName (const char *name)
640 {
641     m_name = name;
642 }
643 
644 std::string
645 DynamicLoaderDarwinKernel::KextImageInfo::GetName () const
646 {
647     return m_name;
648 }
649 
650 void
651 DynamicLoaderDarwinKernel::KextImageInfo::SetUUID (const UUID &uuid)
652 {
653     m_uuid = uuid;
654 }
655 
656 UUID
657 DynamicLoaderDarwinKernel::KextImageInfo::GetUUID () const
658 {
659     return m_uuid;
660 }
661 
662 // Given the m_load_address from the kext summaries, and a UUID, try to create an in-memory
663 // Module at that address.  Require that the MemoryModule have a matching UUID and detect
664 // if this MemoryModule is a kernel or a kext.
665 //
666 // Returns true if m_memory_module_sp is now set to a valid Module.
667 
668 bool
669 DynamicLoaderDarwinKernel::KextImageInfo::ReadMemoryModule (Process *process)
670 {
671     if (m_memory_module_sp.get() != NULL)
672         return true;
673     if (m_load_address == LLDB_INVALID_ADDRESS)
674         return false;
675 
676     FileSpec file_spec;
677     file_spec.SetFile (m_name.c_str(), false);
678 
679     ModuleSP memory_module_sp = process->ReadModuleFromMemory (file_spec, m_load_address);
680 
681     if (memory_module_sp.get() == NULL)
682         return false;
683 
684     bool is_kernel = false;
685     if (memory_module_sp->GetObjectFile())
686     {
687         if (memory_module_sp->GetObjectFile()->GetType() == ObjectFile::eTypeExecutable
688             && memory_module_sp->GetObjectFile()->GetStrata() == ObjectFile::eStrataKernel)
689         {
690             is_kernel = true;
691         }
692         else if (memory_module_sp->GetObjectFile()->GetType() == ObjectFile::eTypeSharedLibrary)
693         {
694             is_kernel = false;
695         }
696     }
697 
698     // If this is a kext, and the kernel specified what UUID we should find at this
699     // load address, require that the memory module have a matching UUID or something
700     // has gone wrong and we should discard it.
701     if (m_uuid.IsValid())
702     {
703         if (m_uuid != memory_module_sp->GetUUID())
704         {
705             return false;
706         }
707     }
708 
709     // If the in-memory Module has a UUID, let's use that.
710     if (!m_uuid.IsValid() && memory_module_sp->GetUUID().IsValid())
711     {
712         m_uuid = memory_module_sp->GetUUID();
713     }
714 
715     m_memory_module_sp = memory_module_sp;
716     m_kernel_image = is_kernel;
717     if (is_kernel)
718     {
719         if (memory_module_sp->GetArchitecture().IsValid())
720         {
721             process->GetTarget().SetArchitecture(memory_module_sp->GetArchitecture());
722         }
723         if (m_uuid.IsValid())
724         {
725             ModuleSP exe_module_sp = process->GetTarget().GetExecutableModule();
726             if (exe_module_sp.get() && exe_module_sp->GetUUID().IsValid())
727             {
728                 if (m_uuid != exe_module_sp->GetUUID())
729                 {
730                     // The user specified a kernel binary that has a different UUID than
731                     // the kernel actually running in memory.  This never ends well;
732                     // clear the user specified kernel binary from the Target.
733 
734                     m_module_sp.reset();
735 
736                     ModuleList user_specified_kernel_list;
737                     user_specified_kernel_list.Append (exe_module_sp);
738                     process->GetTarget().GetImages().Remove (user_specified_kernel_list);
739                 }
740             }
741         }
742     }
743 
744     return true;
745 }
746 
747 bool
748 DynamicLoaderDarwinKernel::KextImageInfo::IsKernel () const
749 {
750     return m_kernel_image == true;
751 }
752 
753 void
754 DynamicLoaderDarwinKernel::KextImageInfo::SetIsKernel (bool is_kernel)
755 {
756     m_kernel_image = is_kernel;
757 }
758 
759 bool
760 DynamicLoaderDarwinKernel::KextImageInfo::LoadImageUsingMemoryModule (Process *process)
761 {
762     if (IsLoaded())
763         return true;
764 
765 
766     Target &target = process->GetTarget();
767 
768     // If we don't have / can't create a memory module for this kext, don't try to load it - we won't
769     // have the correct segment load addresses.
770     if (!ReadMemoryModule (process))
771     {
772         return false;
773     }
774 
775     bool uuid_is_valid = m_uuid.IsValid();
776 
777     if (IsKernel() && uuid_is_valid && m_memory_module_sp.get())
778     {
779         Stream *s = target.GetDebugger().GetOutputFile().get();
780         if (s)
781         {
782             s->Printf ("Kernel UUID: %s\n", m_memory_module_sp->GetUUID().GetAsString().c_str());
783             s->Printf ("Load Address: 0x%" PRIx64 "\n", m_load_address);
784         }
785     }
786 
787     if (!m_module_sp)
788     {
789         // See if the kext has already been loaded into the target, probably by the user doing target modules add.
790         const ModuleList &target_images = target.GetImages();
791         m_module_sp = target_images.FindModule(m_uuid);
792 
793         // Search for the kext on the local filesystem via the UUID
794         if (!m_module_sp && uuid_is_valid)
795         {
796             ModuleSpec module_spec;
797             module_spec.GetUUID() = m_uuid;
798             module_spec.GetArchitecture() = target.GetArchitecture();
799 
800             // For the kernel, we really do need an on-disk file copy of the binary to do anything useful.
801             // This will force a clal to
802             if (IsKernel())
803             {
804                 if (Symbols::DownloadObjectAndSymbolFile (module_spec, true))
805                 {
806                     if (module_spec.GetFileSpec().Exists())
807                     {
808                         m_module_sp.reset(new Module (module_spec.GetFileSpec(), target.GetArchitecture()));
809                         if (m_module_sp.get() && m_module_sp->MatchesModuleSpec (module_spec))
810                         {
811                             ModuleList loaded_module_list;
812                             loaded_module_list.Append (m_module_sp);
813                             target.ModulesDidLoad (loaded_module_list);
814                         }
815                     }
816                 }
817             }
818 
819             // If the current platform is PlatformDarwinKernel, create a ModuleSpec with the filename set
820             // to be the bundle ID for this kext, e.g. "com.apple.filesystems.msdosfs", and ask the platform
821             // to find it.
822             PlatformSP platform_sp (target.GetPlatform());
823             if (!m_module_sp && platform_sp)
824             {
825                 ConstString platform_name (platform_sp->GetPluginName());
826                 static ConstString g_platform_name (PlatformDarwinKernel::GetPluginNameStatic());
827                 if (platform_name == g_platform_name)
828                 {
829                     ModuleSpec kext_bundle_module_spec(module_spec);
830                     FileSpec kext_filespec(m_name.c_str(), false);
831                     kext_bundle_module_spec.GetFileSpec() = kext_filespec;
832                     platform_sp->GetSharedModule (kext_bundle_module_spec, process, m_module_sp, &target.GetExecutableSearchPaths(), NULL, NULL);
833                 }
834             }
835 
836             // Ask the Target to find this file on the local system, if possible.
837             // This will search in the list of currently-loaded files, look in the
838             // standard search paths on the system, and on a Mac it will try calling
839             // the DebugSymbols framework with the UUID to find the binary via its
840             // search methods.
841             if (!m_module_sp)
842             {
843                 m_module_sp = target.GetSharedModule (module_spec);
844             }
845 
846             if (IsKernel() && !m_module_sp)
847             {
848                 Stream *s = target.GetDebugger().GetOutputFile().get();
849                 if (s)
850                 {
851                     s->Printf ("WARNING: Unable to locate kernel binary on the debugger system.\n");
852                 }
853             }
854         }
855 
856         // If we managed to find a module, append it to the target's list of images.
857         // If we also have a memory module, require that they have matching UUIDs
858         if (m_module_sp)
859         {
860             bool uuid_match_ok = true;
861             if (m_memory_module_sp)
862             {
863                 if (m_module_sp->GetUUID() != m_memory_module_sp->GetUUID())
864                 {
865                     uuid_match_ok = false;
866                 }
867             }
868             if (uuid_match_ok)
869             {
870                 target.GetImages().AppendIfNeeded(m_module_sp);
871                 if (IsKernel() && target.GetExecutableModulePointer() != m_module_sp.get())
872                 {
873                     target.SetExecutableModule (m_module_sp, false);
874                 }
875             }
876         }
877     }
878 
879     if (!m_module_sp && !IsKernel() && m_uuid.IsValid() && !m_name.empty())
880     {
881         Stream *s = target.GetDebugger().GetOutputFile().get();
882         if (s)
883         {
884             s->Printf ("warning: Can't find binary/dSYM for %s (%s)\n",
885                        m_name.c_str(), m_uuid.GetAsString().c_str());
886         }
887     }
888 
889     static ConstString g_section_name_LINKEDIT ("__LINKEDIT");
890 
891     if (m_memory_module_sp && m_module_sp)
892     {
893         if (m_module_sp->GetUUID() == m_memory_module_sp->GetUUID())
894         {
895             ObjectFile *ondisk_object_file = m_module_sp->GetObjectFile();
896             ObjectFile *memory_object_file = m_memory_module_sp->GetObjectFile();
897 
898             if (memory_object_file && ondisk_object_file)
899             {
900                 // The memory_module for kexts may have an invalid __LINKEDIT seg; skip it.
901                 const bool ignore_linkedit = !IsKernel ();
902 
903                 SectionList *ondisk_section_list = ondisk_object_file->GetSectionList ();
904                 SectionList *memory_section_list = memory_object_file->GetSectionList ();
905                 if (memory_section_list && ondisk_section_list)
906                 {
907                     const uint32_t num_ondisk_sections = ondisk_section_list->GetSize();
908                     // There may be CTF sections in the memory image so we can't
909                     // always just compare the number of sections (which are actually
910                     // segments in mach-o parlance)
911                     uint32_t sect_idx = 0;
912 
913                     // Use the memory_module's addresses for each section to set the
914                     // file module's load address as appropriate.  We don't want to use
915                     // a single slide value for the entire kext - different segments may
916                     // be slid different amounts by the kext loader.
917 
918                     uint32_t num_sections_loaded = 0;
919                     for (sect_idx=0; sect_idx<num_ondisk_sections; ++sect_idx)
920                     {
921                         SectionSP ondisk_section_sp(ondisk_section_list->GetSectionAtIndex(sect_idx));
922                         if (ondisk_section_sp)
923                         {
924                             // Don't ever load __LINKEDIT as it may or may not be actually
925                             // mapped into memory and there is no current way to tell.
926                             // I filed rdar://problem/12851706 to track being able to tell
927                             // if the __LINKEDIT is actually mapped, but until then, we need
928                             // to not load the __LINKEDIT
929                             if (ignore_linkedit && ondisk_section_sp->GetName() == g_section_name_LINKEDIT)
930                                 continue;
931 
932                             const Section *memory_section = memory_section_list->FindSectionByName(ondisk_section_sp->GetName()).get();
933                             if (memory_section)
934                             {
935                                 target.SetSectionLoadAddress (ondisk_section_sp, memory_section->GetFileAddress());
936                                 ++num_sections_loaded;
937                             }
938                         }
939                     }
940                     if (num_sections_loaded > 0)
941                         m_load_process_stop_id = process->GetStopID();
942                     else
943                         m_module_sp.reset(); // No sections were loaded
944                 }
945                 else
946                     m_module_sp.reset(); // One or both section lists
947             }
948             else
949                 m_module_sp.reset(); // One or both object files missing
950         }
951         else
952             m_module_sp.reset(); // UUID mismatch
953     }
954 
955     bool is_loaded = IsLoaded();
956 
957     if (is_loaded && m_module_sp && IsKernel())
958     {
959         Stream *s = target.GetDebugger().GetOutputFile().get();
960         if (s)
961         {
962             ObjectFile *kernel_object_file = m_module_sp->GetObjectFile();
963             if (kernel_object_file)
964             {
965                 addr_t file_address = kernel_object_file->GetHeaderAddress().GetFileAddress();
966                 if (m_load_address != LLDB_INVALID_ADDRESS && file_address != LLDB_INVALID_ADDRESS)
967                 {
968                     s->Printf ("Kernel slid 0x%" PRIx64 " in memory.\n", m_load_address - file_address);
969                 }
970             }
971             {
972                 s->Printf ("Loaded kernel file %s\n",
973                            m_module_sp->GetFileSpec().GetPath().c_str());
974             }
975             s->Flush ();
976         }
977     }
978     return is_loaded;
979 }
980 
981 uint32_t
982 DynamicLoaderDarwinKernel::KextImageInfo::GetAddressByteSize ()
983 {
984     if (m_memory_module_sp)
985         return m_memory_module_sp->GetArchitecture().GetAddressByteSize();
986     if (m_module_sp)
987         return m_module_sp->GetArchitecture().GetAddressByteSize();
988     return 0;
989 }
990 
991 lldb::ByteOrder
992 DynamicLoaderDarwinKernel::KextImageInfo::GetByteOrder()
993 {
994     if (m_memory_module_sp)
995         return m_memory_module_sp->GetArchitecture().GetByteOrder();
996     if (m_module_sp)
997         return m_module_sp->GetArchitecture().GetByteOrder();
998     return lldb::endian::InlHostByteOrder();
999 }
1000 
1001 lldb_private::ArchSpec
1002 DynamicLoaderDarwinKernel::KextImageInfo::GetArchitecture () const
1003 {
1004     if (m_memory_module_sp)
1005         return m_memory_module_sp->GetArchitecture();
1006     if (m_module_sp)
1007         return m_module_sp->GetArchitecture();
1008     return lldb_private::ArchSpec ();
1009 }
1010 
1011 
1012 //----------------------------------------------------------------------
1013 // Load the kernel module and initialize the "m_kernel" member. Return
1014 // true _only_ if the kernel is loaded the first time through (subsequent
1015 // calls to this function should return false after the kernel has been
1016 // already loaded).
1017 //----------------------------------------------------------------------
1018 void
1019 DynamicLoaderDarwinKernel::LoadKernelModuleIfNeeded()
1020 {
1021     if (!m_kext_summary_header_ptr_addr.IsValid())
1022     {
1023         m_kernel.Clear();
1024         m_kernel.SetModule (m_process->GetTarget().GetExecutableModule());
1025         m_kernel.SetIsKernel(true);
1026 
1027         ConstString kernel_name("mach_kernel");
1028         if (m_kernel.GetModule().get()
1029             && m_kernel.GetModule()->GetObjectFile()
1030             && !m_kernel.GetModule()->GetObjectFile()->GetFileSpec().GetFilename().IsEmpty())
1031         {
1032             kernel_name = m_kernel.GetModule()->GetObjectFile()->GetFileSpec().GetFilename();
1033         }
1034         m_kernel.SetName (kernel_name.AsCString());
1035 
1036         if (m_kernel.GetLoadAddress() == LLDB_INVALID_ADDRESS)
1037         {
1038             m_kernel.SetLoadAddress(m_kernel_load_address);
1039             if (m_kernel.GetLoadAddress() == LLDB_INVALID_ADDRESS && m_kernel.GetModule())
1040             {
1041                 // We didn't get a hint from the process, so we will
1042                 // try the kernel at the address that it exists at in
1043                 // the file if we have one
1044                 ObjectFile *kernel_object_file = m_kernel.GetModule()->GetObjectFile();
1045                 if (kernel_object_file)
1046                 {
1047                     addr_t load_address = kernel_object_file->GetHeaderAddress().GetLoadAddress(&m_process->GetTarget());
1048                     addr_t file_address = kernel_object_file->GetHeaderAddress().GetFileAddress();
1049                     if (load_address != LLDB_INVALID_ADDRESS && load_address != 0)
1050                     {
1051                         m_kernel.SetLoadAddress (load_address);
1052                         if (load_address != file_address)
1053                         {
1054                             // Don't accidentally relocate the kernel to the File address --
1055                             // the Load address has already been set to its actual in-memory address.
1056                             // Mark it as IsLoaded.
1057                             m_kernel.SetProcessStopId (m_process->GetStopID());
1058                         }
1059                     }
1060                     else
1061                     {
1062                         m_kernel.SetLoadAddress(file_address);
1063                     }
1064                 }
1065             }
1066         }
1067 
1068         if (m_kernel.GetLoadAddress() != LLDB_INVALID_ADDRESS)
1069         {
1070             if (!m_kernel.LoadImageUsingMemoryModule (m_process))
1071             {
1072                 m_kernel.LoadImageAtFileAddress (m_process);
1073             }
1074         }
1075 
1076         if (m_kernel.IsLoaded() && m_kernel.GetModule())
1077         {
1078             static ConstString kext_summary_symbol ("gLoadedKextSummaries");
1079             const Symbol *symbol = m_kernel.GetModule()->FindFirstSymbolWithNameAndType (kext_summary_symbol, eSymbolTypeData);
1080             if (symbol)
1081             {
1082                 m_kext_summary_header_ptr_addr = symbol->GetAddress();
1083                 // Update all image infos
1084                 ReadAllKextSummaries ();
1085             }
1086         }
1087         else
1088         {
1089             m_kernel.Clear();
1090         }
1091     }
1092 }
1093 
1094 //----------------------------------------------------------------------
1095 // Static callback function that gets called when our DYLD notification
1096 // breakpoint gets hit. We update all of our image infos and then
1097 // let our super class DynamicLoader class decide if we should stop
1098 // or not (based on global preference).
1099 //----------------------------------------------------------------------
1100 bool
1101 DynamicLoaderDarwinKernel::BreakpointHitCallback (void *baton,
1102                                                   StoppointCallbackContext *context,
1103                                                   user_id_t break_id,
1104                                                   user_id_t break_loc_id)
1105 {
1106     return static_cast<DynamicLoaderDarwinKernel*>(baton)->BreakpointHit (context, break_id, break_loc_id);
1107 }
1108 
1109 bool
1110 DynamicLoaderDarwinKernel::BreakpointHit (StoppointCallbackContext *context,
1111                                           user_id_t break_id,
1112                                           user_id_t break_loc_id)
1113 {
1114     Log *log(GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
1115     if (log)
1116         log->Printf ("DynamicLoaderDarwinKernel::BreakpointHit (...)\n");
1117 
1118     ReadAllKextSummaries ();
1119 
1120     if (log)
1121         PutToLog(log);
1122 
1123     return GetStopWhenImagesChange();
1124 }
1125 
1126 
1127 bool
1128 DynamicLoaderDarwinKernel::ReadKextSummaryHeader ()
1129 {
1130     Mutex::Locker locker(m_mutex);
1131 
1132     // the all image infos is already valid for this process stop ID
1133 
1134     if (m_kext_summary_header_ptr_addr.IsValid())
1135     {
1136         const uint32_t addr_size = m_kernel.GetAddressByteSize ();
1137         const ByteOrder byte_order = m_kernel.GetByteOrder();
1138         Error error;
1139         // Read enough bytes for a "OSKextLoadedKextSummaryHeader" structure
1140         // which is currently 4 uint32_t and a pointer.
1141         uint8_t buf[24];
1142         DataExtractor data (buf, sizeof(buf), byte_order, addr_size);
1143         const size_t count = 4 * sizeof(uint32_t) + addr_size;
1144         const bool prefer_file_cache = false;
1145         if (m_process->GetTarget().ReadPointerFromMemory (m_kext_summary_header_ptr_addr,
1146                                                           prefer_file_cache,
1147                                                           error,
1148                                                           m_kext_summary_header_addr))
1149         {
1150             // We got a valid address for our kext summary header and make sure it isn't NULL
1151             if (m_kext_summary_header_addr.IsValid() &&
1152                 m_kext_summary_header_addr.GetFileAddress() != 0)
1153             {
1154                 const size_t bytes_read = m_process->GetTarget().ReadMemory (m_kext_summary_header_addr, prefer_file_cache, buf, count, error);
1155                 if (bytes_read == count)
1156                 {
1157                     lldb::offset_t offset = 0;
1158                     m_kext_summary_header.version = data.GetU32(&offset);
1159                     if (m_kext_summary_header.version > 128)
1160                     {
1161                         Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1162                         s->Printf ("WARNING: Unable to read kext summary header, got improbable version number %u\n", m_kext_summary_header.version);
1163                         // If we get an improbably large version number, we're probably getting bad memory.
1164                         m_kext_summary_header_addr.Clear();
1165                         return false;
1166                     }
1167                     if (m_kext_summary_header.version >= 2)
1168                     {
1169                         m_kext_summary_header.entry_size = data.GetU32(&offset);
1170                         if (m_kext_summary_header.entry_size > 4096)
1171                         {
1172                             // If we get an improbably large entry_size, we're probably getting bad memory.
1173                             Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1174                             s->Printf ("WARNING: Unable to read kext summary header, got improbable entry_size %u\n", m_kext_summary_header.entry_size);
1175                             m_kext_summary_header_addr.Clear();
1176                             return false;
1177                         }
1178                     }
1179                     else
1180                     {
1181                         // Versions less than 2 didn't have an entry size, it was hard coded
1182                         m_kext_summary_header.entry_size = KERNEL_MODULE_ENTRY_SIZE_VERSION_1;
1183                     }
1184                     m_kext_summary_header.entry_count = data.GetU32(&offset);
1185                     if (m_kext_summary_header.entry_count > 10000)
1186                     {
1187                         // If we get an improbably large number of kexts, we're probably getting bad memory.
1188                         Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1189                         s->Printf ("WARNING: Unable to read kext summary header, got improbable number of kexts %u\n", m_kext_summary_header.entry_count);
1190                         m_kext_summary_header_addr.Clear();
1191                         return false;
1192                     }
1193                     return true;
1194                 }
1195             }
1196         }
1197     }
1198     m_kext_summary_header_addr.Clear();
1199     return false;
1200 }
1201 
1202 // We've either (a) just attached to a new kernel, or (b) the kexts-changed breakpoint was hit
1203 // and we need to figure out what kexts have been added or removed.
1204 // Read the kext summaries from the inferior kernel memory, compare them against the
1205 // m_known_kexts vector and update the m_known_kexts vector as needed to keep in sync with the
1206 // inferior.
1207 
1208 bool
1209 DynamicLoaderDarwinKernel::ParseKextSummaries (const Address &kext_summary_addr, uint32_t count)
1210 {
1211     KextImageInfo::collection kext_summaries;
1212     Log *log(GetLogIfAnyCategoriesSet (LIBLLDB_LOG_DYNAMIC_LOADER));
1213     if (log)
1214         log->Printf ("Kexts-changed breakpoint hit, there are %d kexts currently.\n", count);
1215 
1216     Mutex::Locker locker(m_mutex);
1217 
1218     if (!ReadKextSummaries (kext_summary_addr, count, kext_summaries))
1219         return false;
1220 
1221     // read the plugin.dynamic-loader.darwin-kernel.load-kexts setting -- if the user requested no
1222     // kext loading, don't print any messages about kexts & don't try to read them.
1223     const bool load_kexts = GetGlobalProperties()->GetLoadKexts();
1224 
1225     // By default, all kexts we've loaded in the past are marked as "remove" and all of the kexts
1226     // we just found out about from ReadKextSummaries are marked as "add".
1227     std::vector<bool> to_be_removed(m_known_kexts.size(), true);
1228     std::vector<bool> to_be_added(count, true);
1229 
1230     int number_of_new_kexts_being_added = 0;
1231     int number_of_old_kexts_being_removed = m_known_kexts.size();
1232 
1233     const uint32_t new_kexts_size = kext_summaries.size();
1234     const uint32_t old_kexts_size = m_known_kexts.size();
1235 
1236     // The m_known_kexts vector may have entries that have been Cleared,
1237     // or are a kernel.
1238     for (uint32_t old_kext = 0; old_kext < old_kexts_size; old_kext++)
1239     {
1240         bool ignore = false;
1241         KextImageInfo &image_info = m_known_kexts[old_kext];
1242         if (image_info.IsKernel())
1243         {
1244             ignore = true;
1245         }
1246         else if (image_info.GetLoadAddress() == LLDB_INVALID_ADDRESS && !image_info.GetModule())
1247         {
1248             ignore = true;
1249         }
1250 
1251         if (ignore)
1252         {
1253             number_of_old_kexts_being_removed--;
1254             to_be_removed[old_kext] = false;
1255         }
1256     }
1257 
1258     // Scan over the list of kexts we just read from the kernel, note those that
1259     // need to be added and those already loaded.
1260     for (uint32_t new_kext = 0; new_kext < new_kexts_size; new_kext++)
1261     {
1262         bool add_this_one = true;
1263         for (uint32_t old_kext = 0; old_kext < old_kexts_size; old_kext++)
1264         {
1265             if (m_known_kexts[old_kext] == kext_summaries[new_kext])
1266             {
1267                 // We already have this kext, don't re-load it.
1268                 to_be_added[new_kext] = false;
1269                 // This kext is still present, do not remove it.
1270                 to_be_removed[old_kext] = false;
1271 
1272                 number_of_old_kexts_being_removed--;
1273                 add_this_one = false;
1274                 break;
1275             }
1276         }
1277         if (add_this_one)
1278         {
1279             number_of_new_kexts_being_added++;
1280         }
1281     }
1282 
1283     if (number_of_new_kexts_being_added == 0 && number_of_old_kexts_being_removed == 0)
1284         return true;
1285 
1286     Stream *s = m_process->GetTarget().GetDebugger().GetOutputFile().get();
1287     if (s && load_kexts)
1288     {
1289         if (number_of_new_kexts_being_added > 0 && number_of_old_kexts_being_removed > 0)
1290         {
1291             s->Printf ("Loading %d kext modules and unloading %d kext modules ", number_of_new_kexts_being_added, number_of_old_kexts_being_removed);
1292         }
1293         else if (number_of_new_kexts_being_added > 0)
1294         {
1295             s->Printf ("Loading %d kext modules ", number_of_new_kexts_being_added);
1296         }
1297         else if (number_of_old_kexts_being_removed > 0)
1298         {
1299             s->Printf ("Unloading %d kext modules ", number_of_old_kexts_being_removed);
1300         }
1301     }
1302 
1303     if (log)
1304     {
1305         if (load_kexts)
1306         {
1307             log->Printf ("DynamicLoaderDarwinKernel::ParseKextSummaries: %d kexts added, %d kexts removed", number_of_new_kexts_being_added, number_of_old_kexts_being_removed);
1308         }
1309         else
1310         {
1311             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);
1312         }
1313     }
1314 
1315 
1316     if (number_of_new_kexts_being_added > 0)
1317     {
1318         ModuleList loaded_module_list;
1319 
1320         const uint32_t num_of_new_kexts = kext_summaries.size();
1321         for (uint32_t new_kext = 0; new_kext < num_of_new_kexts; new_kext++)
1322         {
1323             if (to_be_added[new_kext] == true)
1324             {
1325                 KextImageInfo &image_info = kext_summaries[new_kext];
1326                 if (load_kexts)
1327                 {
1328                     if (!image_info.LoadImageUsingMemoryModule (m_process))
1329                     {
1330                         image_info.LoadImageAtFileAddress (m_process);
1331                     }
1332                 }
1333 
1334                 m_known_kexts.push_back(image_info);
1335 
1336                 if (image_info.GetModule() && m_process->GetStopID() == image_info.GetProcessStopId())
1337                     loaded_module_list.AppendIfNeeded (image_info.GetModule());
1338 
1339                 if (s && load_kexts)
1340                     s->Printf (".");
1341 
1342                 if (log)
1343                     kext_summaries[new_kext].PutToLog (log);
1344             }
1345         }
1346         m_process->GetTarget().ModulesDidLoad (loaded_module_list);
1347     }
1348 
1349     if (number_of_old_kexts_being_removed > 0)
1350     {
1351         ModuleList loaded_module_list;
1352         const uint32_t num_of_old_kexts = m_known_kexts.size();
1353         for (uint32_t old_kext = 0; old_kext < num_of_old_kexts; old_kext++)
1354         {
1355             ModuleList unloaded_module_list;
1356             if (to_be_removed[old_kext])
1357             {
1358                 KextImageInfo &image_info = m_known_kexts[old_kext];
1359                 // You can't unload the kernel.
1360                 if (!image_info.IsKernel())
1361                 {
1362                     if (image_info.GetModule())
1363                     {
1364                         unloaded_module_list.AppendIfNeeded (image_info.GetModule());
1365                     }
1366                     if (s)
1367                         s->Printf (".");
1368                     image_info.Clear();
1369                     // should pull it out of the KextImageInfos vector but that would mutate the list and invalidate
1370                     // the to_be_removed bool vector; leaving it in place once Cleared() is relatively harmless.
1371                 }
1372             }
1373             m_process->GetTarget().ModulesDidUnload (unloaded_module_list, false);
1374         }
1375     }
1376 
1377     if (s && load_kexts)
1378     {
1379         s->Printf (" done.\n");
1380         s->Flush ();
1381     }
1382 
1383     return true;
1384 }
1385 
1386 uint32_t
1387 DynamicLoaderDarwinKernel::ReadKextSummaries (const Address &kext_summary_addr,
1388                                               uint32_t image_infos_count,
1389                                               KextImageInfo::collection &image_infos)
1390 {
1391     const ByteOrder endian = m_kernel.GetByteOrder();
1392     const uint32_t addr_size = m_kernel.GetAddressByteSize();
1393 
1394     image_infos.resize(image_infos_count);
1395     const size_t count = image_infos.size() * m_kext_summary_header.entry_size;
1396     DataBufferHeap data(count, 0);
1397     Error error;
1398 
1399     const bool prefer_file_cache = false;
1400     const size_t bytes_read = m_process->GetTarget().ReadMemory (kext_summary_addr,
1401                                                                  prefer_file_cache,
1402                                                                  data.GetBytes(),
1403                                                                  data.GetByteSize(),
1404                                                                  error);
1405     if (bytes_read == count)
1406     {
1407 
1408         DataExtractor extractor (data.GetBytes(), data.GetByteSize(), endian, addr_size);
1409         uint32_t i=0;
1410         for (uint32_t kext_summary_offset = 0;
1411              i < image_infos.size() && extractor.ValidOffsetForDataOfSize(kext_summary_offset, m_kext_summary_header.entry_size);
1412              ++i, kext_summary_offset += m_kext_summary_header.entry_size)
1413         {
1414             lldb::offset_t offset = kext_summary_offset;
1415             const void *name_data = extractor.GetData(&offset, KERNEL_MODULE_MAX_NAME);
1416             if (name_data == NULL)
1417                 break;
1418             image_infos[i].SetName ((const char *) name_data);
1419             UUID uuid (extractor.GetData (&offset, 16), 16);
1420             image_infos[i].SetUUID (uuid);
1421             image_infos[i].SetLoadAddress (extractor.GetU64(&offset));
1422             image_infos[i].SetSize (extractor.GetU64(&offset));
1423         }
1424         if (i < image_infos.size())
1425             image_infos.resize(i);
1426     }
1427     else
1428     {
1429         image_infos.clear();
1430     }
1431     return image_infos.size();
1432 }
1433 
1434 bool
1435 DynamicLoaderDarwinKernel::ReadAllKextSummaries ()
1436 {
1437     Mutex::Locker locker(m_mutex);
1438 
1439     if (ReadKextSummaryHeader ())
1440     {
1441         if (m_kext_summary_header.entry_count > 0 && m_kext_summary_header_addr.IsValid())
1442         {
1443             Address summary_addr (m_kext_summary_header_addr);
1444             summary_addr.Slide(m_kext_summary_header.GetSize());
1445             if (!ParseKextSummaries (summary_addr, m_kext_summary_header.entry_count))
1446             {
1447                 m_known_kexts.clear();
1448             }
1449             return true;
1450         }
1451     }
1452     return false;
1453 }
1454 
1455 //----------------------------------------------------------------------
1456 // Dump an image info structure to the file handle provided.
1457 //----------------------------------------------------------------------
1458 void
1459 DynamicLoaderDarwinKernel::KextImageInfo::PutToLog (Log *log) const
1460 {
1461     if (log == NULL)
1462         return;
1463     const uint8_t *u = (uint8_t *) m_uuid.GetBytes();
1464 
1465     if (m_load_address == LLDB_INVALID_ADDRESS)
1466     {
1467         if (u)
1468         {
1469             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)",
1470                         u[ 0], u[ 1], u[ 2], u[ 3],
1471                         u[ 4], u[ 5], u[ 6], u[ 7],
1472                         u[ 8], u[ 9], u[10], u[11],
1473                         u[12], u[13], u[14], u[15],
1474                         m_name.c_str());
1475         }
1476         else
1477             log->Printf("\tname=\"%s\" (UNLOADED)", m_name.c_str());
1478     }
1479     else
1480     {
1481         if (u)
1482         {
1483             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\"",
1484                         m_load_address, m_size,
1485                         u[ 0], u[ 1], u[ 2], u[ 3], u[ 4], u[ 5], u[ 6], u[ 7],
1486                         u[ 8], u[ 9], u[10], u[11], u[12], u[13], u[14], u[15],
1487                         m_name.c_str());
1488         }
1489         else
1490         {
1491             log->Printf("\t[0x%16.16" PRIx64 " - 0x%16.16" PRIx64 ") name=\"%s\"",
1492                         m_load_address, m_load_address+m_size, m_name.c_str());
1493         }
1494     }
1495 }
1496 
1497 //----------------------------------------------------------------------
1498 // Dump the _dyld_all_image_infos members and all current image infos
1499 // that we have parsed to the file handle provided.
1500 //----------------------------------------------------------------------
1501 void
1502 DynamicLoaderDarwinKernel::PutToLog(Log *log) const
1503 {
1504     if (log == NULL)
1505         return;
1506 
1507     Mutex::Locker locker(m_mutex);
1508     log->Printf("gLoadedKextSummaries = 0x%16.16" PRIx64 " { version=%u, entry_size=%u, entry_count=%u }",
1509                 m_kext_summary_header_addr.GetFileAddress(),
1510                 m_kext_summary_header.version,
1511                 m_kext_summary_header.entry_size,
1512                 m_kext_summary_header.entry_count);
1513 
1514     size_t i;
1515     const size_t count = m_known_kexts.size();
1516     if (count > 0)
1517     {
1518         log->PutCString("Loaded:");
1519         for (i = 0; i<count; i++)
1520             m_known_kexts[i].PutToLog(log);
1521     }
1522 }
1523 
1524 void
1525 DynamicLoaderDarwinKernel::PrivateInitialize(Process *process)
1526 {
1527     DEBUG_PRINTF("DynamicLoaderDarwinKernel::%s() process state = %s\n", __FUNCTION__, StateAsCString(m_process->GetState()));
1528     Clear(true);
1529     m_process = process;
1530 }
1531 
1532 void
1533 DynamicLoaderDarwinKernel::SetNotificationBreakpointIfNeeded ()
1534 {
1535     if (m_break_id == LLDB_INVALID_BREAK_ID && m_kernel.GetModule())
1536     {
1537         DEBUG_PRINTF("DynamicLoaderDarwinKernel::%s() process state = %s\n", __FUNCTION__, StateAsCString(m_process->GetState()));
1538 
1539 
1540         const bool internal_bp = true;
1541         const bool hardware = false;
1542         const LazyBool skip_prologue = eLazyBoolNo;
1543         FileSpecList module_spec_list;
1544         module_spec_list.Append (m_kernel.GetModule()->GetFileSpec());
1545         Breakpoint *bp = m_process->GetTarget().CreateBreakpoint (&module_spec_list,
1546                                                                   NULL,
1547                                                                   "OSKextLoadedKextSummariesUpdated",
1548                                                                   eFunctionNameTypeFull,
1549                                                                   skip_prologue,
1550                                                                   internal_bp,
1551                                                                   hardware).get();
1552 
1553         bp->SetCallback (DynamicLoaderDarwinKernel::BreakpointHitCallback, this, true);
1554         m_break_id = bp->GetID();
1555     }
1556 }
1557 
1558 //----------------------------------------------------------------------
1559 // Member function that gets called when the process state changes.
1560 //----------------------------------------------------------------------
1561 void
1562 DynamicLoaderDarwinKernel::PrivateProcessStateChanged (Process *process, StateType state)
1563 {
1564     DEBUG_PRINTF("DynamicLoaderDarwinKernel::%s(%s)\n", __FUNCTION__, StateAsCString(state));
1565     switch (state)
1566     {
1567     case eStateConnected:
1568     case eStateAttaching:
1569     case eStateLaunching:
1570     case eStateInvalid:
1571     case eStateUnloaded:
1572     case eStateExited:
1573     case eStateDetached:
1574         Clear(false);
1575         break;
1576 
1577     case eStateStopped:
1578         UpdateIfNeeded();
1579         break;
1580 
1581     case eStateRunning:
1582     case eStateStepping:
1583     case eStateCrashed:
1584     case eStateSuspended:
1585         break;
1586     }
1587 }
1588 
1589 ThreadPlanSP
1590 DynamicLoaderDarwinKernel::GetStepThroughTrampolinePlan (Thread &thread, bool stop_others)
1591 {
1592     ThreadPlanSP thread_plan_sp;
1593     Log *log(GetLogIfAllCategoriesSet (LIBLLDB_LOG_STEP));
1594     if (log)
1595         log->Printf ("Could not find symbol for step through.");
1596     return thread_plan_sp;
1597 }
1598 
1599 Error
1600 DynamicLoaderDarwinKernel::CanLoadImage ()
1601 {
1602     Error error;
1603     error.SetErrorString("always unsafe to load or unload shared libraries in the darwin kernel");
1604     return error;
1605 }
1606 
1607 void
1608 DynamicLoaderDarwinKernel::Initialize()
1609 {
1610     PluginManager::RegisterPlugin (GetPluginNameStatic(),
1611                                    GetPluginDescriptionStatic(),
1612                                    CreateInstance,
1613                                    DebuggerInitialize);
1614 }
1615 
1616 void
1617 DynamicLoaderDarwinKernel::Terminate()
1618 {
1619     PluginManager::UnregisterPlugin (CreateInstance);
1620 }
1621 
1622 void
1623 DynamicLoaderDarwinKernel::DebuggerInitialize (lldb_private::Debugger &debugger)
1624 {
1625     if (!PluginManager::GetSettingForDynamicLoaderPlugin (debugger, DynamicLoaderDarwinKernelProperties::GetSettingName()))
1626     {
1627         const bool is_global_setting = true;
1628         PluginManager::CreateSettingForDynamicLoaderPlugin (debugger,
1629                                                             GetGlobalProperties()->GetValueProperties(),
1630                                                             ConstString ("Properties for the DynamicLoaderDarwinKernel plug-in."),
1631                                                             is_global_setting);
1632     }
1633 }
1634 
1635 lldb_private::ConstString
1636 DynamicLoaderDarwinKernel::GetPluginNameStatic()
1637 {
1638     static ConstString g_name("darwin-kernel");
1639     return g_name;
1640 }
1641 
1642 const char *
1643 DynamicLoaderDarwinKernel::GetPluginDescriptionStatic()
1644 {
1645     return "Dynamic loader plug-in that watches for shared library loads/unloads in the MacOSX kernel.";
1646 }
1647 
1648 
1649 //------------------------------------------------------------------
1650 // PluginInterface protocol
1651 //------------------------------------------------------------------
1652 lldb_private::ConstString
1653 DynamicLoaderDarwinKernel::GetPluginName()
1654 {
1655     return GetPluginNameStatic();
1656 }
1657 
1658 uint32_t
1659 DynamicLoaderDarwinKernel::GetPluginVersion()
1660 {
1661     return 1;
1662 }
1663 
1664 lldb::ByteOrder
1665 DynamicLoaderDarwinKernel::GetByteOrderFromMagic (uint32_t magic)
1666 {
1667     switch (magic)
1668     {
1669         case llvm::MachO::MH_MAGIC:
1670         case llvm::MachO::MH_MAGIC_64:
1671             return lldb::endian::InlHostByteOrder();
1672 
1673         case llvm::MachO::MH_CIGAM:
1674         case llvm::MachO::MH_CIGAM_64:
1675             if (lldb::endian::InlHostByteOrder() == lldb::eByteOrderBig)
1676                 return lldb::eByteOrderLittle;
1677             else
1678                 return lldb::eByteOrderBig;
1679 
1680         default:
1681             break;
1682     }
1683     return lldb::eByteOrderInvalid;
1684 }
1685 
1686