xref: /llvm-project/lldb/source/Plugins/DynamicLoader/Darwin-Kernel/DynamicLoaderDarwinKernel.h (revision 16ff8604690ea63a3a82dd3b156061afb84dbcf1)
1 //===-- DynamicLoaderDarwinKernel.h -----------------------------*- 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 #ifndef liblldb_DynamicLoaderDarwinKernel_h_
11 #define liblldb_DynamicLoaderDarwinKernel_h_
12 
13 // C Includes
14 // C++ Includes
15 #include <mutex>
16 #include <string>
17 #include <vector>
18 
19 // Other libraries and framework includes
20 // Project includes
21 #include "lldb/Target/DynamicLoader.h"
22 #include "lldb/Host/FileSpec.h"
23 #include "lldb/Host/TimeValue.h"
24 #include "lldb/Core/UUID.h"
25 #include "lldb/Target/Process.h"
26 
27 class DynamicLoaderDarwinKernel : public lldb_private::DynamicLoader
28 {
29 public:
30     DynamicLoaderDarwinKernel(lldb_private::Process *process, lldb::addr_t kernel_addr);
31 
32     ~DynamicLoaderDarwinKernel() override;
33 
34     //------------------------------------------------------------------
35     // Static Functions
36     //------------------------------------------------------------------
37     static void
38     Initialize();
39 
40     static void
41     Terminate();
42 
43     static lldb_private::ConstString
44     GetPluginNameStatic();
45 
46     static const char *
47     GetPluginDescriptionStatic();
48 
49     static lldb_private::DynamicLoader *
50     CreateInstance (lldb_private::Process *process, bool force);
51 
52     static void
53     DebuggerInitialize (lldb_private::Debugger &debugger);
54 
55     static lldb::addr_t
56     SearchForDarwinKernel (lldb_private::Process *process);
57 
58     //------------------------------------------------------------------
59     /// Called after attaching a process.
60     ///
61     /// Allow DynamicLoader plug-ins to execute some code after
62     /// attaching to a process.
63     //------------------------------------------------------------------
64     void
65     DidAttach() override;
66 
67     void
68     DidLaunch() override;
69 
70     lldb::ThreadPlanSP
71     GetStepThroughTrampolinePlan(lldb_private::Thread &thread,
72                                  bool stop_others) override;
73 
74     lldb_private::Error
75     CanLoadImage() override;
76 
77     //------------------------------------------------------------------
78     // PluginInterface protocol
79     //------------------------------------------------------------------
80     lldb_private::ConstString
81     GetPluginName() override;
82 
83     uint32_t
84     GetPluginVersion() override;
85 
86 protected:
87     void
88     PrivateInitialize (lldb_private::Process *process);
89 
90     void
91     PrivateProcessStateChanged (lldb_private::Process *process,
92                                 lldb::StateType state);
93 
94     void
95     UpdateIfNeeded();
96 
97     void
98     LoadKernelModuleIfNeeded ();
99 
100     void
101     Clear (bool clear_process);
102 
103     void
104     PutToLog (lldb_private::Log *log) const;
105 
106     static bool
107     BreakpointHitCallback (void *baton,
108                            lldb_private::StoppointCallbackContext *context,
109                            lldb::user_id_t break_id,
110                            lldb::user_id_t break_loc_id);
111 
112     bool
113     BreakpointHit (lldb_private::StoppointCallbackContext *context,
114                    lldb::user_id_t break_id,
115                    lldb::user_id_t break_loc_id);
116     uint32_t
117     GetAddrByteSize()
118     {
119         return m_kernel.GetAddressByteSize();
120     }
121 
122     static lldb::ByteOrder
123     GetByteOrderFromMagic (uint32_t magic);
124 
125     enum
126     {
127         KERNEL_MODULE_MAX_NAME = 64u,
128         // Versions less than 2 didn't have an entry size,
129         // they had a 64 bit name, 16 byte UUID, 8 byte addr,
130         // 8 byte size, 8 byte version, 4 byte load tag, and
131         // 4 byte flags
132         KERNEL_MODULE_ENTRY_SIZE_VERSION_1 = 64u + 16u + 8u + 8u + 8u + 4u + 4u
133     };
134 
135     // class KextImageInfo represents a single kext or kernel binary image.
136     // The class was designed to hold the information from the OSKextLoadedKextSummary
137     // structure (in libkern/libkern/OSKextLibPrivate.h from xnu).  The kernel maintains
138     // a list of loded kexts in memory (the OSKextLoadedKextSummaryHeader structure,
139     // which points to an array of OSKextLoadedKextSummary's).
140     //
141     // A KextImageInfos may have -
142     //
143     // 1. The load address, name, UUID, and size of a kext/kernel binary in memory
144     //    (read straight out of the kernel's list-of-kexts loaded)
145     // 2. A ModuleSP based on a MemoryModule read out of the kernel's memory
146     //    (very unlikely to have any symbolic information)
147     // 3. A ModuleSP for an on-disk copy of the kext binary, possibly with debug info
148     //    or a dSYM
149     //
150     // For performance reasons, the developer may prefer that lldb not load the kexts out
151     // of memory at the start of a kernel session.  But we should build up / maintain a
152     // list of kexts that the kernel has told us about so we can relocate a kext module
153     // later if the user explicitly adds it to the target.
154 
155     class KextImageInfo
156     {
157     public:
158         KextImageInfo () :
159             m_name (),
160             m_module_sp (),
161             m_memory_module_sp (),
162             m_load_process_stop_id (UINT32_MAX),
163             m_uuid (),
164             m_load_address (LLDB_INVALID_ADDRESS),
165             m_size (0),
166             m_kernel_image (false)
167         { }
168 
169         void
170         Clear ()
171         {
172             m_load_address = LLDB_INVALID_ADDRESS;
173             m_size = 0;
174             m_name.clear ();
175             m_uuid.Clear();
176             m_module_sp.reset();
177             m_memory_module_sp.reset();
178             m_load_process_stop_id = UINT32_MAX;
179         }
180 
181         bool
182         LoadImageAtFileAddress (lldb_private::Process *process);
183 
184         bool
185         LoadImageUsingMemoryModule (lldb_private::Process *process);
186 
187         bool
188         IsLoaded ()
189         {
190             return m_load_process_stop_id != UINT32_MAX;
191         }
192 
193         void
194         SetLoadAddress (lldb::addr_t load_addr);     // Address of the Mach-O header for this binary
195 
196         lldb::addr_t
197         GetLoadAddress () const;                     // Address of the Mach-O header for this binary
198 
199         lldb_private::UUID
200         GetUUID () const;
201 
202         void
203         SetUUID (const lldb_private::UUID &uuid);
204 
205         void
206         SetName (const char *);
207 
208         std::string
209         GetName () const;
210 
211         void
212         SetModule (lldb::ModuleSP module);
213 
214         lldb::ModuleSP
215         GetModule ();
216 
217         // try to fill in m_memory_module_sp from memory based on the m_load_address
218         bool
219         ReadMemoryModule (lldb_private::Process *process);
220 
221         bool
222         IsKernel () const;            // true if this is the mach_kernel; false if this is a kext
223 
224         void
225         SetIsKernel (bool is_kernel);
226 
227         uint64_t
228         GetSize () const;
229 
230         void
231         SetSize (uint64_t size);
232 
233         uint32_t
234         GetProcessStopId () const;    // the stop-id when this binary was first noticed
235 
236         void
237         SetProcessStopId (uint32_t stop_id);
238 
239         bool
240         operator== (const KextImageInfo &rhs);
241 
242         uint32_t
243         GetAddressByteSize ();        // as determined by Mach-O header
244 
245         lldb::ByteOrder
246         GetByteOrder();               // as determined by Mach-O header
247 
248         lldb_private::ArchSpec
249         GetArchitecture () const;     // as determined by Mach-O header
250 
251         void
252         PutToLog (lldb_private::Log *log) const;
253 
254         typedef std::vector<KextImageInfo> collection;
255         typedef collection::iterator iterator;
256         typedef collection::const_iterator const_iterator;
257 
258     private:
259         std::string              m_name;
260         lldb::ModuleSP           m_module_sp;
261         lldb::ModuleSP           m_memory_module_sp;
262         uint32_t                 m_load_process_stop_id; // the stop-id when this module was added to the Target
263         lldb_private::UUID       m_uuid;                 // UUID for this dylib if it has one, else all zeros
264         lldb::addr_t             m_load_address;
265         uint64_t                 m_size;
266         bool                     m_kernel_image;         // true if this is the kernel, false if this is a kext
267     };
268 
269     struct OSKextLoadedKextSummaryHeader
270     {
271         uint32_t version;
272         uint32_t entry_size;
273         uint32_t entry_count;
274         lldb::addr_t image_infos_addr;
275 
276         OSKextLoadedKextSummaryHeader() :
277             version (0),
278             entry_size (0),
279             entry_count (0),
280             image_infos_addr (LLDB_INVALID_ADDRESS)
281         {
282         }
283 
284         uint32_t
285         GetSize()
286         {
287             switch (version)
288             {
289                 case 0: return 0;   // Can't know the size without a valid version
290                 case 1: return 8;   // Version 1 only had a version + entry_count
291                 default: break;
292             }
293             // Version 2 and above has version, entry_size, entry_count, and reserved
294             return 16;
295         }
296 
297         void
298         Clear()
299         {
300             version = 0;
301             entry_size = 0;
302             entry_count = 0;
303             image_infos_addr = LLDB_INVALID_ADDRESS;
304         }
305 
306         bool
307         IsValid() const
308         {
309             return version >= 1 || version <= 2;
310         }
311     };
312 
313     void
314     RegisterNotificationCallbacks();
315 
316     void
317     UnregisterNotificationCallbacks();
318 
319     void
320     SetNotificationBreakpointIfNeeded ();
321 
322     bool
323     ReadAllKextSummaries ();
324 
325     bool
326     ReadKextSummaryHeader ();
327 
328     bool
329     ParseKextSummaries (const lldb_private::Address &kext_summary_addr,
330                         uint32_t count);
331 
332     void
333     UpdateImageInfosHeaderAndLoadCommands(KextImageInfo::collection &image_infos,
334                                           uint32_t infos_count,
335                                           bool update_executable);
336 
337     uint32_t
338     ReadKextSummaries (const lldb_private::Address &kext_summary_addr,
339                        uint32_t image_infos_count,
340                        KextImageInfo::collection &image_infos);
341 
342     static lldb::addr_t
343     SearchForKernelAtSameLoadAddr (lldb_private::Process *process);
344 
345     static lldb::addr_t
346     SearchForKernelWithDebugHints (lldb_private::Process *process);
347 
348     static lldb::addr_t
349     SearchForKernelNearPC (lldb_private::Process *process);
350 
351     static lldb::addr_t
352     SearchForKernelViaExhaustiveSearch (lldb_private::Process *process);
353 
354     static lldb_private::UUID
355     CheckForKernelImageAtAddress (lldb::addr_t addr, lldb_private::Process *process);
356 
357     lldb::addr_t  m_kernel_load_address;
358     KextImageInfo m_kernel;                 // Info about the current kernel image being used
359 
360     lldb_private::Address          m_kext_summary_header_ptr_addr;
361     lldb_private::Address          m_kext_summary_header_addr;
362     OSKextLoadedKextSummaryHeader  m_kext_summary_header;
363     KextImageInfo::collection      m_known_kexts;
364     mutable std::recursive_mutex m_mutex;
365     lldb::user_id_t                m_break_id;
366 
367 private:
368     DISALLOW_COPY_AND_ASSIGN (DynamicLoaderDarwinKernel);
369 };
370 
371 #endif // liblldb_DynamicLoaderDarwinKernel_h_
372