1 //===-- EmulateInstruction.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 #include "lldb/Core/EmulateInstruction.h"
11 
12 #include "lldb/Core/Address.h"
13 #include "lldb/Core/DataBufferHeap.h"
14 #include "lldb/Core/DataExtractor.h"
15 #include "lldb/Core/Error.h"
16 #include "lldb/Core/PluginManager.h"
17 #include "lldb/Core/RegisterValue.h"
18 #include "lldb/Core/StreamFile.h"
19 #include "lldb/Core/StreamString.h"
20 #include "lldb/Host/Endian.h"
21 #include "lldb/Symbol/UnwindPlan.h"
22 #include "lldb/Target/Process.h"
23 #include "lldb/Target/RegisterContext.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Target/Thread.h"
26 
27 using namespace lldb;
28 using namespace lldb_private;
29 
30 EmulateInstruction*
31 EmulateInstruction::FindPlugin (const ArchSpec &arch, InstructionType supported_inst_type, const char *plugin_name)
32 {
33     EmulateInstructionCreateInstance create_callback = NULL;
34     if (plugin_name)
35     {
36         create_callback  = PluginManager::GetEmulateInstructionCreateCallbackForPluginName (plugin_name);
37         if (create_callback)
38         {
39            	EmulateInstruction *emulate_insn_ptr = create_callback(arch, supported_inst_type);
40             if (emulate_insn_ptr)
41                 return emulate_insn_ptr;
42         }
43     }
44     else
45     {
46         for (uint32_t idx = 0; (create_callback = PluginManager::GetEmulateInstructionCreateCallbackAtIndex(idx)) != NULL; ++idx)
47         {
48             EmulateInstruction *emulate_insn_ptr = create_callback(arch, supported_inst_type);
49             if (emulate_insn_ptr)
50                 return emulate_insn_ptr;
51         }
52     }
53     return NULL;
54 }
55 
56 EmulateInstruction::EmulateInstruction (const ArchSpec &arch) :
57     m_arch (arch),
58     m_baton (NULL),
59     m_read_mem_callback (&ReadMemoryDefault),
60     m_write_mem_callback (&WriteMemoryDefault),
61     m_read_reg_callback (&ReadRegisterDefault),
62     m_write_reg_callback (&WriteRegisterDefault),
63     m_addr (LLDB_INVALID_ADDRESS)
64 {
65     ::memset (&m_opcode, 0, sizeof (m_opcode));
66 }
67 
68 
69 bool
70 EmulateInstruction::ReadRegister (const RegisterInfo *reg_info, RegisterValue& reg_value)
71 {
72     if (m_read_reg_callback)
73         return m_read_reg_callback (this, m_baton, reg_info, reg_value);
74     return false;
75 }
76 
77 bool
78 EmulateInstruction::ReadRegister (uint32_t reg_kind, uint32_t reg_num, RegisterValue& reg_value)
79 {
80     RegisterInfo reg_info;
81     if (GetRegisterInfo(reg_kind, reg_num, reg_info))
82         return ReadRegister (&reg_info, reg_value);
83     return false;
84 }
85 
86 uint64_t
87 EmulateInstruction::ReadRegisterUnsigned (uint32_t reg_kind,
88                                           uint32_t reg_num,
89                                           uint64_t fail_value,
90                                           bool *success_ptr)
91 {
92     RegisterValue reg_value;
93     if (ReadRegister (reg_kind, reg_num, reg_value))
94         return reg_value.GetAsUInt64(fail_value, success_ptr);
95     if (success_ptr)
96         *success_ptr = false;
97     return fail_value;
98 }
99 
100 uint64_t
101 EmulateInstruction::ReadRegisterUnsigned (const RegisterInfo *reg_info,
102                                           uint64_t fail_value,
103                                           bool *success_ptr)
104 {
105     RegisterValue reg_value;
106     if (ReadRegister (reg_info, reg_value))
107         return reg_value.GetAsUInt64(fail_value, success_ptr);
108     if (success_ptr)
109         *success_ptr = false;
110     return fail_value;
111 }
112 
113 bool
114 EmulateInstruction::WriteRegister (const Context &context,
115                                    const RegisterInfo *reg_info,
116                                    const RegisterValue& reg_value)
117 {
118     if (m_write_reg_callback)
119         return m_write_reg_callback (this, m_baton, context, reg_info, reg_value);
120     return false;
121 }
122 
123 bool
124 EmulateInstruction::WriteRegister (const Context &context,
125                                    uint32_t reg_kind,
126                                    uint32_t reg_num,
127                                    const RegisterValue& reg_value)
128 {
129     RegisterInfo reg_info;
130     if (GetRegisterInfo(reg_kind, reg_num, reg_info))
131         return WriteRegister (context, &reg_info, reg_value);
132     return false;
133 }
134 
135 
136 bool
137 EmulateInstruction::WriteRegisterUnsigned (const Context &context,
138                                            uint32_t reg_kind,
139                                            uint32_t reg_num,
140                                            uint64_t uint_value)
141 {
142 
143     RegisterInfo reg_info;
144     if (GetRegisterInfo(reg_kind, reg_num, reg_info))
145     {
146         RegisterValue reg_value;
147         if (reg_value.SetUInt(uint_value, reg_info.byte_size))
148             return WriteRegister (context, &reg_info, reg_value);
149     }
150     return false;
151 }
152 
153 bool
154 EmulateInstruction::WriteRegisterUnsigned (const Context &context,
155                                            const RegisterInfo *reg_info,
156                                            uint64_t uint_value)
157 {
158 
159     if (reg_info)
160     {
161         RegisterValue reg_value;
162         if (reg_value.SetUInt(uint_value, reg_info->byte_size))
163                 return WriteRegister (context, reg_info, reg_value);
164     }
165     return false;
166 }
167 
168 size_t
169 EmulateInstruction::ReadMemory (const Context &context,
170                                 lldb::addr_t addr,
171                                 void *dst,
172                                 size_t dst_len)
173 {
174     if (m_read_mem_callback)
175         return m_read_mem_callback (this, m_baton, context, addr, dst, dst_len) == dst_len;
176     return false;
177 }
178 
179 uint64_t
180 EmulateInstruction::ReadMemoryUnsigned (const Context &context, lldb::addr_t addr, size_t byte_size, uint64_t fail_value, bool *success_ptr)
181 {
182     uint64_t uval64 = 0;
183     bool success = false;
184     if (byte_size <= 8)
185     {
186         uint8_t buf[sizeof(uint64_t)];
187         size_t bytes_read = m_read_mem_callback (this, m_baton, context, addr, buf, byte_size);
188         if (bytes_read == byte_size)
189         {
190             uint32_t offset = 0;
191             DataExtractor data (buf, byte_size, GetByteOrder(), GetAddressByteSize());
192             uval64 = data.GetMaxU64 (&offset, byte_size);
193             success = true;
194         }
195     }
196 
197     if (success_ptr)
198         *success_ptr = success;
199 
200     if (!success)
201         uval64 = fail_value;
202     return uval64;
203 }
204 
205 
206 bool
207 EmulateInstruction::WriteMemoryUnsigned (const Context &context,
208                                          lldb::addr_t addr,
209                                          uint64_t uval,
210                                          size_t uval_byte_size)
211 {
212     StreamString strm(Stream::eBinary, GetAddressByteSize(), GetByteOrder());
213     strm.PutMaxHex64 (uval, uval_byte_size);
214 
215     size_t bytes_written = m_write_mem_callback (this, m_baton, context, addr, strm.GetData(), uval_byte_size);
216     if (bytes_written == uval_byte_size)
217         return true;
218     return false;
219 }
220 
221 bool
222 EmulateInstruction::WriteMemory (const Context &context,
223                                  lldb::addr_t addr,
224                                  const void *src,
225                                  size_t src_len)
226 {
227     if (m_write_mem_callback)
228         return m_write_mem_callback (this, m_baton, context, addr, src, src_len) == src_len;
229     return false;
230 }
231 
232 
233 void
234 EmulateInstruction::SetBaton (void *baton)
235 {
236     m_baton = baton;
237 }
238 
239 void
240 EmulateInstruction::SetCallbacks (ReadMemoryCallback read_mem_callback,
241                                   WriteMemoryCallback write_mem_callback,
242                                   ReadRegisterCallback read_reg_callback,
243                                   WriteRegisterCallback write_reg_callback)
244 {
245     m_read_mem_callback = read_mem_callback;
246     m_write_mem_callback = write_mem_callback;
247     m_read_reg_callback = read_reg_callback;
248     m_write_reg_callback = write_reg_callback;
249 }
250 
251 void
252 EmulateInstruction::SetReadMemCallback (ReadMemoryCallback read_mem_callback)
253 {
254     m_read_mem_callback = read_mem_callback;
255 }
256 
257 
258 void
259 EmulateInstruction::SetWriteMemCallback (WriteMemoryCallback write_mem_callback)
260 {
261     m_write_mem_callback = write_mem_callback;
262 }
263 
264 
265 void
266 EmulateInstruction::SetReadRegCallback (ReadRegisterCallback read_reg_callback)
267 {
268     m_read_reg_callback = read_reg_callback;
269 }
270 
271 
272 void
273 EmulateInstruction::SetWriteRegCallback (WriteRegisterCallback write_reg_callback)
274 {
275     m_write_reg_callback = write_reg_callback;
276 }
277 
278 
279 
280 //
281 //  Read & Write Memory and Registers callback functions.
282 //
283 
284 size_t
285 EmulateInstruction::ReadMemoryFrame (EmulateInstruction *instruction,
286                                      void *baton,
287                                      const Context &context,
288                                      lldb::addr_t addr,
289                                      void *dst,
290                                      size_t length)
291 {
292     if (!baton)
293         return 0;
294 
295 
296     StackFrame *frame = (StackFrame *) baton;
297 
298     DataBufferSP data_sp (new DataBufferHeap (length, '\0'));
299     Error error;
300 
301     size_t bytes_read = frame->GetThread().GetProcess().ReadMemory (addr, data_sp->GetBytes(), data_sp->GetByteSize(),
302                                                                     error);
303 
304     if (bytes_read > 0)
305         ((DataBufferHeap *) data_sp.get())->CopyData (dst, length);
306 
307     return bytes_read;
308 }
309 
310 size_t
311 EmulateInstruction::WriteMemoryFrame (EmulateInstruction *instruction,
312                                       void *baton,
313                                       const Context &context,
314                                       lldb::addr_t addr,
315                                       const void *dst,
316                                       size_t length)
317 {
318     if (!baton)
319         return 0;
320 
321     StackFrame *frame = (StackFrame *) baton;
322 
323     lldb::DataBufferSP data_sp (new DataBufferHeap (dst, length));
324     if (data_sp)
325     {
326         length = data_sp->GetByteSize();
327         if (length > 0)
328         {
329             Error error;
330             size_t bytes_written = frame->GetThread().GetProcess().WriteMemory (addr, data_sp->GetBytes(), length,
331                                                                                 error);
332 
333             return bytes_written;
334         }
335     }
336 
337     return 0;
338 }
339 
340 bool
341 EmulateInstruction::ReadRegisterFrame  (EmulateInstruction *instruction,
342                                         void *baton,
343                                         const RegisterInfo *reg_info,
344                                         RegisterValue &reg_value)
345 {
346     if (!baton)
347         return false;
348 
349     StackFrame *frame = (StackFrame *) baton;
350     return frame->GetRegisterContext()->ReadRegister (reg_info, reg_value);
351 }
352 
353 bool
354 EmulateInstruction::WriteRegisterFrame (EmulateInstruction *instruction,
355                                         void *baton,
356                                         const Context &context,
357                                         const RegisterInfo *reg_info,
358                                         const RegisterValue &reg_value)
359 {
360     if (!baton)
361         return false;
362 
363     StackFrame *frame = (StackFrame *) baton;
364     return frame->GetRegisterContext()->WriteRegister (reg_info, reg_value);
365 }
366 
367 size_t
368 EmulateInstruction::ReadMemoryDefault (EmulateInstruction *instruction,
369                                        void *baton,
370                                        const Context &context,
371                                        lldb::addr_t addr,
372                                        void *dst,
373                                        size_t length)
374 {
375     StreamFile strm (stdout, false);
376     strm.Printf ("    Read from Memory (address = 0x%llx, length = %zu, context = ", addr, length);
377     context.Dump (strm, instruction);
378     strm.EOL();
379     *((uint64_t *) dst) = 0xdeadbeef;
380     return length;
381 }
382 
383 size_t
384 EmulateInstruction::WriteMemoryDefault (EmulateInstruction *instruction,
385                                         void *baton,
386                                         const Context &context,
387                                         lldb::addr_t addr,
388                                         const void *dst,
389                                         size_t length)
390 {
391     StreamFile strm (stdout, false);
392     strm.Printf ("    Write to Memory (address = 0x%llx, length = %zu, context = ", addr, length);
393     context.Dump (strm, instruction);
394     strm.EOL();
395     return length;
396 }
397 
398 bool
399 EmulateInstruction::ReadRegisterDefault  (EmulateInstruction *instruction,
400                                           void *baton,
401                                           const RegisterInfo *reg_info,
402                                           RegisterValue &reg_value)
403 {
404     StreamFile strm (stdout, false);
405     strm.Printf ("  Read Register (%s)\n", reg_info->name);
406     uint32_t reg_kind, reg_num;
407     if (GetBestRegisterKindAndNumber (reg_info, reg_kind, reg_num))
408         reg_value.SetUInt64((uint64_t)reg_kind << 24 | reg_num);
409     else
410         reg_value.SetUInt64(0);
411 
412     return true;
413 }
414 
415 bool
416 EmulateInstruction::WriteRegisterDefault (EmulateInstruction *instruction,
417                                           void *baton,
418                                           const Context &context,
419                                           const RegisterInfo *reg_info,
420                                           const RegisterValue &reg_value)
421 {
422     StreamFile strm (stdout, false);
423     strm.Printf ("    Write to Register (name = %s, value = " , reg_info->name);
424     reg_value.Dump(&strm, reg_info, false, false, eFormatDefault);
425     strm.PutCString (", context = ");
426     context.Dump (strm, instruction);
427     strm.EOL();
428     return true;
429 }
430 
431 void
432 EmulateInstruction::Context::Dump (Stream &strm,
433                                    EmulateInstruction *instruction) const
434 {
435     switch (type)
436     {
437         case eContextReadOpcode:
438             strm.PutCString ("reading opcode");
439             break;
440 
441         case eContextImmediate:
442             strm.PutCString ("immediate");
443             break;
444 
445         case eContextPushRegisterOnStack:
446             strm.PutCString ("push register");
447             break;
448 
449         case eContextPopRegisterOffStack:
450             strm.PutCString ("pop register");
451             break;
452 
453         case eContextAdjustStackPointer:
454             strm.PutCString ("adjust sp");
455             break;
456 
457         case eContextAdjustBaseRegister:
458             strm.PutCString ("adjusting (writing value back to) a base register");
459             break;
460 
461         case eContextRegisterPlusOffset:
462             strm.PutCString ("register + offset");
463             break;
464 
465         case eContextRegisterStore:
466             strm.PutCString ("store register");
467             break;
468 
469         case eContextRegisterLoad:
470             strm.PutCString ("load register");
471             break;
472 
473         case eContextRelativeBranchImmediate:
474             strm.PutCString ("relative branch immediate");
475             break;
476 
477         case eContextAbsoluteBranchRegister:
478             strm.PutCString ("absolute branch register");
479             break;
480 
481         case eContextSupervisorCall:
482             strm.PutCString ("supervisor call");
483             break;
484 
485         case eContextTableBranchReadMemory:
486             strm.PutCString ("table branch read memory");
487             break;
488 
489         case eContextWriteRegisterRandomBits:
490             strm.PutCString ("write random bits to a register");
491             break;
492 
493         case eContextWriteMemoryRandomBits:
494             strm.PutCString ("write random bits to a memory address");
495             break;
496 
497         case eContextArithmetic:
498             strm.PutCString ("arithmetic");
499             break;
500 
501         case eContextReturnFromException:
502             strm.PutCString ("return from exception");
503             break;
504 
505         default:
506             strm.PutCString ("unrecognized context.");
507             break;
508     }
509 
510     switch (info_type)
511     {
512     case eInfoTypeRegisterPlusOffset:
513         {
514             strm.Printf (" (reg_plus_offset = %s%+lld)",
515                          info.RegisterPlusOffset.reg.name,
516                          info.RegisterPlusOffset.signed_offset);
517         }
518         break;
519 
520     case eInfoTypeRegisterPlusIndirectOffset:
521         {
522             strm.Printf (" (reg_plus_reg = %s + %s)",
523                          info.RegisterPlusIndirectOffset.base_reg.name,
524                          info.RegisterPlusIndirectOffset.offset_reg.name);
525         }
526         break;
527 
528     case eInfoTypeRegisterToRegisterPlusOffset:
529         {
530             strm.Printf (" (base_and_imm_offset = %s%+lld, data_reg = %s)",
531                          info.RegisterToRegisterPlusOffset.base_reg.name,
532                          info.RegisterToRegisterPlusOffset.offset,
533                          info.RegisterToRegisterPlusOffset.data_reg.name);
534         }
535         break;
536 
537     case eInfoTypeRegisterToRegisterPlusIndirectOffset:
538         {
539             strm.Printf (" (base_and_reg_offset = %s + %s, data_reg = %s)",
540                          info.RegisterToRegisterPlusIndirectOffset.base_reg.name,
541                          info.RegisterToRegisterPlusIndirectOffset.offset_reg.name,
542                          info.RegisterToRegisterPlusIndirectOffset.data_reg.name);
543         }
544         break;
545 
546     case eInfoTypeRegisterRegisterOperands:
547         {
548             strm.Printf (" (register to register binary op: %s and %s)",
549                          info.RegisterRegisterOperands.operand1.name,
550                          info.RegisterRegisterOperands.operand2.name);
551         }
552         break;
553 
554     case eInfoTypeOffset:
555         strm.Printf (" (signed_offset = %+lld)", info.signed_offset);
556         break;
557 
558     case eInfoTypeRegister:
559         strm.Printf (" (reg = %s)", info.reg.name);
560         break;
561 
562     case eInfoTypeImmediate:
563         strm.Printf (" (unsigned_immediate = %llu (0x%16.16llx))",
564                      info.unsigned_immediate,
565                      info.unsigned_immediate);
566         break;
567 
568     case eInfoTypeImmediateSigned:
569         strm.Printf (" (signed_immediate = %+lld (0x%16.16llx))",
570                      info.signed_immediate,
571                      info.signed_immediate);
572         break;
573 
574     case eInfoTypeAddress:
575         strm.Printf (" (address = 0x%llx)", info.address);
576         break;
577 
578     case eInfoTypeISAAndImmediate:
579         strm.Printf (" (isa = %u, unsigned_immediate = %u (0x%8.8x))",
580                      info.ISAAndImmediate.isa,
581                      info.ISAAndImmediate.unsigned_data32,
582                      info.ISAAndImmediate.unsigned_data32);
583         break;
584 
585     case eInfoTypeISAAndImmediateSigned:
586         strm.Printf (" (isa = %u, signed_immediate = %i (0x%8.8x))",
587                      info.ISAAndImmediateSigned.isa,
588                      info.ISAAndImmediateSigned.signed_data32,
589                      info.ISAAndImmediateSigned.signed_data32);
590         break;
591 
592     case eInfoTypeISA:
593         strm.Printf (" (isa = %u)", info.isa);
594         break;
595 
596     case eInfoTypeNoArgs:
597         break;
598 
599     default:
600         strm.Printf (" (unknown <info_type>)");
601         break;
602     }
603 }
604 
605 bool
606 EmulateInstruction::SetInstruction (const Opcode &opcode, const Address &inst_addr, Target *target)
607 {
608     m_opcode = opcode;
609     m_addr = LLDB_INVALID_ADDRESS;
610     if (inst_addr.IsValid())
611     {
612         if (target)
613             m_addr = inst_addr.GetLoadAddress (target);
614         if (m_addr == LLDB_INVALID_ADDRESS)
615             m_addr = inst_addr.GetFileAddress ();
616     }
617     return true;
618 }
619 
620 bool
621 EmulateInstruction::GetBestRegisterKindAndNumber (const RegisterInfo *reg_info,
622                                                   uint32_t &reg_kind,
623                                                   uint32_t &reg_num)
624 {
625     // Generic and DWARF should be the two most popular register kinds when
626     // emulating instructions since they are the most platform agnostic...
627     reg_num = reg_info->kinds[eRegisterKindGeneric];
628     if (reg_num != LLDB_INVALID_REGNUM)
629     {
630         reg_kind = eRegisterKindGeneric;
631         return true;
632     }
633 
634     reg_num = reg_info->kinds[eRegisterKindDWARF];
635     if (reg_num != LLDB_INVALID_REGNUM)
636     {
637         reg_kind = eRegisterKindDWARF;
638         return true;
639     }
640 
641     reg_num = reg_info->kinds[eRegisterKindLLDB];
642     if (reg_num != LLDB_INVALID_REGNUM)
643     {
644         reg_kind = eRegisterKindLLDB;
645         return true;
646     }
647 
648     reg_num = reg_info->kinds[eRegisterKindGCC];
649     if (reg_num != LLDB_INVALID_REGNUM)
650     {
651         reg_kind = eRegisterKindGCC;
652         return true;
653     }
654 
655     reg_num = reg_info->kinds[eRegisterKindGDB];
656     if (reg_num != LLDB_INVALID_REGNUM)
657     {
658         reg_kind = eRegisterKindGDB;
659         return true;
660     }
661     return false;
662 }
663 
664 uint32_t
665 EmulateInstruction::GetInternalRegisterNumber (RegisterContext *reg_ctx, const RegisterInfo &reg_info)
666 {
667     uint32_t reg_kind, reg_num;
668     if (reg_ctx && GetBestRegisterKindAndNumber (&reg_info, reg_kind, reg_num))
669         return reg_ctx->ConvertRegisterKindToRegisterNumber (reg_kind, reg_num);
670     return LLDB_INVALID_REGNUM;
671 }
672 
673 
674 bool
675 EmulateInstruction::CreateFunctionEntryUnwind (UnwindPlan &unwind_plan)
676 {
677     unwind_plan.Clear();
678     return false;
679 }
680 
681 
682