1 //===-- IRMemoryMap.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/Expression/IRMemoryMap.h"
11 #include "lldb/Core/Scalar.h"
12 #include "lldb/Target/MemoryRegionInfo.h"
13 #include "lldb/Target/Process.h"
14 #include "lldb/Target/Target.h"
15 #include "lldb/Utility/DataBufferHeap.h"
16 #include "lldb/Utility/DataExtractor.h"
17 #include "lldb/Utility/LLDBAssert.h"
18 #include "lldb/Utility/Log.h"
19 #include "lldb/Utility/Status.h"
20 
21 using namespace lldb_private;
22 
23 IRMemoryMap::IRMemoryMap(lldb::TargetSP target_sp) : m_target_wp(target_sp) {
24   if (target_sp)
25     m_process_wp = target_sp->GetProcessSP();
26 }
27 
28 IRMemoryMap::~IRMemoryMap() {
29   lldb::ProcessSP process_sp = m_process_wp.lock();
30 
31   if (process_sp) {
32     AllocationMap::iterator iter;
33 
34     Status err;
35 
36     while ((iter = m_allocations.begin()) != m_allocations.end()) {
37       err.Clear();
38       if (iter->second.m_leak)
39         m_allocations.erase(iter);
40       else
41         Free(iter->first, err);
42     }
43   }
44 }
45 
46 lldb::addr_t IRMemoryMap::FindSpace(size_t size) {
47   // The FindSpace algorithm's job is to find a region of memory that the
48   // underlying process is unlikely to be using.
49   //
50   // The memory returned by this function will never be written to.  The only
51   // point is that it should not shadow process memory if possible, so that
52   // expressions processing real values from the process do not use the wrong
53   // data.
54   //
55   // If the process can in fact allocate memory (CanJIT() lets us know this)
56   // then this can be accomplished just be allocating memory in the inferior.
57   // Then no guessing is required.
58 
59   lldb::TargetSP target_sp = m_target_wp.lock();
60   lldb::ProcessSP process_sp = m_process_wp.lock();
61 
62   const bool process_is_alive = process_sp && process_sp->IsAlive();
63 
64   lldb::addr_t ret = LLDB_INVALID_ADDRESS;
65   if (size == 0)
66     return ret;
67 
68   if (process_is_alive && process_sp->CanJIT()) {
69     Status alloc_error;
70 
71     ret = process_sp->AllocateMemory(size, lldb::ePermissionsReadable |
72                                                lldb::ePermissionsWritable,
73                                      alloc_error);
74 
75     if (!alloc_error.Success())
76       return LLDB_INVALID_ADDRESS;
77     else
78       return ret;
79   }
80 
81   // At this point we know that we need to hunt.
82   //
83   // First, go to the end of the existing allocations we've made if there are
84   // any allocations.  Otherwise start at the beginning of memory.
85 
86   if (m_allocations.empty()) {
87     ret = 0x0;
88   } else {
89     auto back = m_allocations.rbegin();
90     lldb::addr_t addr = back->first;
91     size_t alloc_size = back->second.m_size;
92     ret = llvm::alignTo(addr + alloc_size, 4096);
93   }
94 
95   // Now, if it's possible to use the GetMemoryRegionInfo API to detect mapped
96   // regions, walk forward through memory until a region is found that has
97   // adequate space for our allocation.
98   if (process_is_alive) {
99     const uint64_t end_of_memory = process_sp->GetAddressByteSize() == 8
100                                        ? 0xffffffffffffffffull
101                                        : 0xffffffffull;
102 
103     lldbassert(process_sp->GetAddressByteSize() == 4 ||
104                end_of_memory != 0xffffffffull);
105 
106     MemoryRegionInfo region_info;
107     Status err = process_sp->GetMemoryRegionInfo(ret, region_info);
108     if (err.Success()) {
109       while (true) {
110         if (region_info.GetReadable() != MemoryRegionInfo::OptionalBool::eNo ||
111             region_info.GetWritable() != MemoryRegionInfo::OptionalBool::eNo ||
112             region_info.GetExecutable() !=
113                 MemoryRegionInfo::OptionalBool::eNo) {
114           if (region_info.GetRange().GetRangeEnd() - 1 >= end_of_memory) {
115             ret = LLDB_INVALID_ADDRESS;
116             break;
117           } else {
118             ret = region_info.GetRange().GetRangeEnd();
119           }
120         } else if (ret + size < region_info.GetRange().GetRangeEnd()) {
121           return ret;
122         } else {
123           // ret stays the same.  We just need to walk a bit further.
124         }
125 
126         err = process_sp->GetMemoryRegionInfo(
127             region_info.GetRange().GetRangeEnd(), region_info);
128         if (err.Fail()) {
129           lldbassert(0 && "GetMemoryRegionInfo() succeeded, then failed");
130           ret = LLDB_INVALID_ADDRESS;
131           break;
132         }
133       }
134     }
135   }
136 
137   // We've tried our algorithm, and it didn't work.  Now we have to reset back
138   // to the end of the allocations we've already reported, or use a 'sensible'
139   // default if this is our first allocation.
140 
141   if (m_allocations.empty()) {
142     uint32_t address_byte_size = GetAddressByteSize();
143     if (address_byte_size != UINT32_MAX) {
144       switch (address_byte_size) {
145       case 8:
146         ret = 0xffffffff00000000ull;
147         break;
148       case 4:
149         ret = 0xee000000ull;
150         break;
151       default:
152         break;
153       }
154     }
155   } else {
156     auto back = m_allocations.rbegin();
157     lldb::addr_t addr = back->first;
158     size_t alloc_size = back->second.m_size;
159     ret = llvm::alignTo(addr + alloc_size, 4096);
160   }
161 
162   return ret;
163 }
164 
165 IRMemoryMap::AllocationMap::iterator
166 IRMemoryMap::FindAllocation(lldb::addr_t addr, size_t size) {
167   if (addr == LLDB_INVALID_ADDRESS)
168     return m_allocations.end();
169 
170   AllocationMap::iterator iter = m_allocations.lower_bound(addr);
171 
172   if (iter == m_allocations.end() || iter->first > addr) {
173     if (iter == m_allocations.begin())
174       return m_allocations.end();
175     iter--;
176   }
177 
178   if (iter->first <= addr && iter->first + iter->second.m_size >= addr + size)
179     return iter;
180 
181   return m_allocations.end();
182 }
183 
184 bool IRMemoryMap::IntersectsAllocation(lldb::addr_t addr, size_t size) const {
185   if (addr == LLDB_INVALID_ADDRESS)
186     return false;
187 
188   AllocationMap::const_iterator iter = m_allocations.lower_bound(addr);
189 
190   // Since we only know that the returned interval begins at a location greater
191   // than or equal to where the given interval begins, it's possible that the
192   // given interval intersects either the returned interval or the previous
193   // interval.  Thus, we need to check both. Note that we only need to check
194   // these two intervals.  Since all intervals are disjoint it is not possible
195   // that an adjacent interval does not intersect, but a non-adjacent interval
196   // does intersect.
197   if (iter != m_allocations.end()) {
198     if (AllocationsIntersect(addr, size, iter->second.m_process_start,
199                              iter->second.m_size))
200       return true;
201   }
202 
203   if (iter != m_allocations.begin()) {
204     --iter;
205     if (AllocationsIntersect(addr, size, iter->second.m_process_start,
206                              iter->second.m_size))
207       return true;
208   }
209 
210   return false;
211 }
212 
213 bool IRMemoryMap::AllocationsIntersect(lldb::addr_t addr1, size_t size1,
214                                        lldb::addr_t addr2, size_t size2) {
215   // Given two half open intervals [A, B) and [X, Y), the only 6 permutations
216   // that satisfy A<B and X<Y are the following:
217   // A B X Y
218   // A X B Y  (intersects)
219   // A X Y B  (intersects)
220   // X A B Y  (intersects)
221   // X A Y B  (intersects)
222   // X Y A B
223   // The first is B <= X, and the last is Y <= A. So the condition is !(B <= X
224   // || Y <= A)), or (X < B && A < Y)
225   return (addr2 < (addr1 + size1)) && (addr1 < (addr2 + size2));
226 }
227 
228 lldb::ByteOrder IRMemoryMap::GetByteOrder() {
229   lldb::ProcessSP process_sp = m_process_wp.lock();
230 
231   if (process_sp)
232     return process_sp->GetByteOrder();
233 
234   lldb::TargetSP target_sp = m_target_wp.lock();
235 
236   if (target_sp)
237     return target_sp->GetArchitecture().GetByteOrder();
238 
239   return lldb::eByteOrderInvalid;
240 }
241 
242 uint32_t IRMemoryMap::GetAddressByteSize() {
243   lldb::ProcessSP process_sp = m_process_wp.lock();
244 
245   if (process_sp)
246     return process_sp->GetAddressByteSize();
247 
248   lldb::TargetSP target_sp = m_target_wp.lock();
249 
250   if (target_sp)
251     return target_sp->GetArchitecture().GetAddressByteSize();
252 
253   return UINT32_MAX;
254 }
255 
256 ExecutionContextScope *IRMemoryMap::GetBestExecutionContextScope() const {
257   lldb::ProcessSP process_sp = m_process_wp.lock();
258 
259   if (process_sp)
260     return process_sp.get();
261 
262   lldb::TargetSP target_sp = m_target_wp.lock();
263 
264   if (target_sp)
265     return target_sp.get();
266 
267   return NULL;
268 }
269 
270 IRMemoryMap::Allocation::Allocation(lldb::addr_t process_alloc,
271                                     lldb::addr_t process_start, size_t size,
272                                     uint32_t permissions, uint8_t alignment,
273                                     AllocationPolicy policy)
274     : m_process_alloc(process_alloc), m_process_start(process_start),
275       m_size(size), m_permissions(permissions), m_alignment(alignment),
276       m_policy(policy), m_leak(false) {
277   switch (policy) {
278   default:
279     assert(0 && "We cannot reach this!");
280   case eAllocationPolicyHostOnly:
281     m_data.SetByteSize(size);
282     memset(m_data.GetBytes(), 0, size);
283     break;
284   case eAllocationPolicyProcessOnly:
285     break;
286   case eAllocationPolicyMirror:
287     m_data.SetByteSize(size);
288     memset(m_data.GetBytes(), 0, size);
289     break;
290   }
291 }
292 
293 lldb::addr_t IRMemoryMap::Malloc(size_t size, uint8_t alignment,
294                                  uint32_t permissions, AllocationPolicy policy,
295                                  bool zero_memory, Status &error) {
296   lldb_private::Log *log(
297       lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS));
298   error.Clear();
299 
300   lldb::ProcessSP process_sp;
301   lldb::addr_t allocation_address = LLDB_INVALID_ADDRESS;
302   lldb::addr_t aligned_address = LLDB_INVALID_ADDRESS;
303 
304   size_t alignment_mask = alignment - 1;
305   size_t allocation_size;
306 
307   if (size == 0)
308     allocation_size = alignment;
309   else
310     allocation_size = (size & alignment_mask)
311                           ? ((size + alignment) & (~alignment_mask))
312                           : size;
313 
314   switch (policy) {
315   default:
316     error.SetErrorToGenericError();
317     error.SetErrorString("Couldn't malloc: invalid allocation policy");
318     return LLDB_INVALID_ADDRESS;
319   case eAllocationPolicyHostOnly:
320     allocation_address = FindSpace(allocation_size);
321     if (allocation_address == LLDB_INVALID_ADDRESS) {
322       error.SetErrorToGenericError();
323       error.SetErrorString("Couldn't malloc: address space is full");
324       return LLDB_INVALID_ADDRESS;
325     }
326     break;
327   case eAllocationPolicyMirror:
328     process_sp = m_process_wp.lock();
329     if (log)
330       log->Printf("IRMemoryMap::%s process_sp=0x%" PRIx64
331                   ", process_sp->CanJIT()=%s, process_sp->IsAlive()=%s",
332                   __FUNCTION__, (lldb::addr_t)process_sp.get(),
333                   process_sp && process_sp->CanJIT() ? "true" : "false",
334                   process_sp && process_sp->IsAlive() ? "true" : "false");
335     if (process_sp && process_sp->CanJIT() && process_sp->IsAlive()) {
336       if (!zero_memory)
337         allocation_address =
338             process_sp->AllocateMemory(allocation_size, permissions, error);
339       else
340         allocation_address =
341             process_sp->CallocateMemory(allocation_size, permissions, error);
342 
343       if (!error.Success())
344         return LLDB_INVALID_ADDRESS;
345     } else {
346       if (log)
347         log->Printf("IRMemoryMap::%s switching to eAllocationPolicyHostOnly "
348                     "due to failed condition (see previous expr log message)",
349                     __FUNCTION__);
350       policy = eAllocationPolicyHostOnly;
351       allocation_address = FindSpace(allocation_size);
352       if (allocation_address == LLDB_INVALID_ADDRESS) {
353         error.SetErrorToGenericError();
354         error.SetErrorString("Couldn't malloc: address space is full");
355         return LLDB_INVALID_ADDRESS;
356       }
357     }
358     break;
359   case eAllocationPolicyProcessOnly:
360     process_sp = m_process_wp.lock();
361     if (process_sp) {
362       if (process_sp->CanJIT() && process_sp->IsAlive()) {
363         if (!zero_memory)
364           allocation_address =
365               process_sp->AllocateMemory(allocation_size, permissions, error);
366         else
367           allocation_address =
368               process_sp->CallocateMemory(allocation_size, permissions, error);
369 
370         if (!error.Success())
371           return LLDB_INVALID_ADDRESS;
372       } else {
373         error.SetErrorToGenericError();
374         error.SetErrorString(
375             "Couldn't malloc: process doesn't support allocating memory");
376         return LLDB_INVALID_ADDRESS;
377       }
378     } else {
379       error.SetErrorToGenericError();
380       error.SetErrorString("Couldn't malloc: process doesn't exist, and this "
381                            "memory must be in the process");
382       return LLDB_INVALID_ADDRESS;
383     }
384     break;
385   }
386 
387   lldb::addr_t mask = alignment - 1;
388   aligned_address = (allocation_address + mask) & (~mask);
389 
390   m_allocations[aligned_address] =
391       Allocation(allocation_address, aligned_address, allocation_size,
392                  permissions, alignment, policy);
393 
394   if (zero_memory) {
395     Status write_error;
396     std::vector<uint8_t> zero_buf(size, 0);
397     WriteMemory(aligned_address, zero_buf.data(), size, write_error);
398   }
399 
400   if (log) {
401     const char *policy_string;
402 
403     switch (policy) {
404     default:
405       policy_string = "<invalid policy>";
406       break;
407     case eAllocationPolicyHostOnly:
408       policy_string = "eAllocationPolicyHostOnly";
409       break;
410     case eAllocationPolicyProcessOnly:
411       policy_string = "eAllocationPolicyProcessOnly";
412       break;
413     case eAllocationPolicyMirror:
414       policy_string = "eAllocationPolicyMirror";
415       break;
416     }
417 
418     log->Printf("IRMemoryMap::Malloc (%" PRIu64 ", 0x%" PRIx64 ", 0x%" PRIx64
419                 ", %s) -> 0x%" PRIx64,
420                 (uint64_t)allocation_size, (uint64_t)alignment,
421                 (uint64_t)permissions, policy_string, aligned_address);
422   }
423 
424   return aligned_address;
425 }
426 
427 void IRMemoryMap::Leak(lldb::addr_t process_address, Status &error) {
428   error.Clear();
429 
430   AllocationMap::iterator iter = m_allocations.find(process_address);
431 
432   if (iter == m_allocations.end()) {
433     error.SetErrorToGenericError();
434     error.SetErrorString("Couldn't leak: allocation doesn't exist");
435     return;
436   }
437 
438   Allocation &allocation = iter->second;
439 
440   allocation.m_leak = true;
441 }
442 
443 void IRMemoryMap::Free(lldb::addr_t process_address, Status &error) {
444   error.Clear();
445 
446   AllocationMap::iterator iter = m_allocations.find(process_address);
447 
448   if (iter == m_allocations.end()) {
449     error.SetErrorToGenericError();
450     error.SetErrorString("Couldn't free: allocation doesn't exist");
451     return;
452   }
453 
454   Allocation &allocation = iter->second;
455 
456   switch (allocation.m_policy) {
457   default:
458   case eAllocationPolicyHostOnly: {
459     lldb::ProcessSP process_sp = m_process_wp.lock();
460     if (process_sp) {
461       if (process_sp->CanJIT() && process_sp->IsAlive())
462         process_sp->DeallocateMemory(
463             allocation.m_process_alloc); // FindSpace allocated this for real
464     }
465 
466     break;
467   }
468   case eAllocationPolicyMirror:
469   case eAllocationPolicyProcessOnly: {
470     lldb::ProcessSP process_sp = m_process_wp.lock();
471     if (process_sp)
472       process_sp->DeallocateMemory(allocation.m_process_alloc);
473   }
474   }
475 
476   if (lldb_private::Log *log =
477           lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
478     log->Printf("IRMemoryMap::Free (0x%" PRIx64 ") freed [0x%" PRIx64
479                 "..0x%" PRIx64 ")",
480                 (uint64_t)process_address, iter->second.m_process_start,
481                 iter->second.m_process_start + iter->second.m_size);
482   }
483 
484   m_allocations.erase(iter);
485 }
486 
487 bool IRMemoryMap::GetAllocSize(lldb::addr_t address, size_t &size) {
488   AllocationMap::iterator iter = FindAllocation(address, size);
489   if (iter == m_allocations.end())
490     return false;
491 
492   Allocation &al = iter->second;
493 
494   if (address > (al.m_process_start + al.m_size)) {
495     size = 0;
496     return false;
497   }
498 
499   if (address > al.m_process_start) {
500     int dif = address - al.m_process_start;
501     size = al.m_size - dif;
502     return true;
503   }
504 
505   size = al.m_size;
506   return true;
507 }
508 
509 void IRMemoryMap::WriteMemory(lldb::addr_t process_address,
510                               const uint8_t *bytes, size_t size,
511                               Status &error) {
512   error.Clear();
513 
514   AllocationMap::iterator iter = FindAllocation(process_address, size);
515 
516   if (iter == m_allocations.end()) {
517     lldb::ProcessSP process_sp = m_process_wp.lock();
518 
519     if (process_sp) {
520       process_sp->WriteMemory(process_address, bytes, size, error);
521       return;
522     }
523 
524     error.SetErrorToGenericError();
525     error.SetErrorString("Couldn't write: no allocation contains the target "
526                          "range and the process doesn't exist");
527     return;
528   }
529 
530   Allocation &allocation = iter->second;
531 
532   uint64_t offset = process_address - allocation.m_process_start;
533 
534   lldb::ProcessSP process_sp;
535 
536   switch (allocation.m_policy) {
537   default:
538     error.SetErrorToGenericError();
539     error.SetErrorString("Couldn't write: invalid allocation policy");
540     return;
541   case eAllocationPolicyHostOnly:
542     if (!allocation.m_data.GetByteSize()) {
543       error.SetErrorToGenericError();
544       error.SetErrorString("Couldn't write: data buffer is empty");
545       return;
546     }
547     ::memcpy(allocation.m_data.GetBytes() + offset, bytes, size);
548     break;
549   case eAllocationPolicyMirror:
550     if (!allocation.m_data.GetByteSize()) {
551       error.SetErrorToGenericError();
552       error.SetErrorString("Couldn't write: data buffer is empty");
553       return;
554     }
555     ::memcpy(allocation.m_data.GetBytes() + offset, bytes, size);
556     process_sp = m_process_wp.lock();
557     if (process_sp) {
558       process_sp->WriteMemory(process_address, bytes, size, error);
559       if (!error.Success())
560         return;
561     }
562     break;
563   case eAllocationPolicyProcessOnly:
564     process_sp = m_process_wp.lock();
565     if (process_sp) {
566       process_sp->WriteMemory(process_address, bytes, size, error);
567       if (!error.Success())
568         return;
569     }
570     break;
571   }
572 
573   if (lldb_private::Log *log =
574           lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
575     log->Printf("IRMemoryMap::WriteMemory (0x%" PRIx64 ", 0x%" PRIx64
576                 ", 0x%" PRId64 ") went to [0x%" PRIx64 "..0x%" PRIx64 ")",
577                 (uint64_t)process_address, (uint64_t)bytes, (uint64_t)size,
578                 (uint64_t)allocation.m_process_start,
579                 (uint64_t)allocation.m_process_start +
580                     (uint64_t)allocation.m_size);
581   }
582 }
583 
584 void IRMemoryMap::WriteScalarToMemory(lldb::addr_t process_address,
585                                       Scalar &scalar, size_t size,
586                                       Status &error) {
587   error.Clear();
588 
589   if (size == UINT32_MAX)
590     size = scalar.GetByteSize();
591 
592   if (size > 0) {
593     uint8_t buf[32];
594     const size_t mem_size =
595         scalar.GetAsMemoryData(buf, size, GetByteOrder(), error);
596     if (mem_size > 0) {
597       return WriteMemory(process_address, buf, mem_size, error);
598     } else {
599       error.SetErrorToGenericError();
600       error.SetErrorString(
601           "Couldn't write scalar: failed to get scalar as memory data");
602     }
603   } else {
604     error.SetErrorToGenericError();
605     error.SetErrorString("Couldn't write scalar: its size was zero");
606   }
607   return;
608 }
609 
610 void IRMemoryMap::WritePointerToMemory(lldb::addr_t process_address,
611                                        lldb::addr_t address, Status &error) {
612   error.Clear();
613 
614   Scalar scalar(address);
615 
616   WriteScalarToMemory(process_address, scalar, GetAddressByteSize(), error);
617 }
618 
619 void IRMemoryMap::ReadMemory(uint8_t *bytes, lldb::addr_t process_address,
620                              size_t size, Status &error) {
621   error.Clear();
622 
623   AllocationMap::iterator iter = FindAllocation(process_address, size);
624 
625   if (iter == m_allocations.end()) {
626     lldb::ProcessSP process_sp = m_process_wp.lock();
627 
628     if (process_sp) {
629       process_sp->ReadMemory(process_address, bytes, size, error);
630       return;
631     }
632 
633     lldb::TargetSP target_sp = m_target_wp.lock();
634 
635     if (target_sp) {
636       Address absolute_address(process_address);
637       target_sp->ReadMemory(absolute_address, false, bytes, size, error);
638       return;
639     }
640 
641     error.SetErrorToGenericError();
642     error.SetErrorString("Couldn't read: no allocation contains the target "
643                          "range, and neither the process nor the target exist");
644     return;
645   }
646 
647   Allocation &allocation = iter->second;
648 
649   uint64_t offset = process_address - allocation.m_process_start;
650 
651   if (offset > allocation.m_size) {
652     error.SetErrorToGenericError();
653     error.SetErrorString("Couldn't read: data is not in the allocation");
654     return;
655   }
656 
657   lldb::ProcessSP process_sp;
658 
659   switch (allocation.m_policy) {
660   default:
661     error.SetErrorToGenericError();
662     error.SetErrorString("Couldn't read: invalid allocation policy");
663     return;
664   case eAllocationPolicyHostOnly:
665     if (!allocation.m_data.GetByteSize()) {
666       error.SetErrorToGenericError();
667       error.SetErrorString("Couldn't read: data buffer is empty");
668       return;
669     }
670     if (allocation.m_data.GetByteSize() < offset + size) {
671       error.SetErrorToGenericError();
672       error.SetErrorString("Couldn't read: not enough underlying data");
673       return;
674     }
675 
676     ::memcpy(bytes, allocation.m_data.GetBytes() + offset, size);
677     break;
678   case eAllocationPolicyMirror:
679     process_sp = m_process_wp.lock();
680     if (process_sp) {
681       process_sp->ReadMemory(process_address, bytes, size, error);
682       if (!error.Success())
683         return;
684     } else {
685       if (!allocation.m_data.GetByteSize()) {
686         error.SetErrorToGenericError();
687         error.SetErrorString("Couldn't read: data buffer is empty");
688         return;
689       }
690       ::memcpy(bytes, allocation.m_data.GetBytes() + offset, size);
691     }
692     break;
693   case eAllocationPolicyProcessOnly:
694     process_sp = m_process_wp.lock();
695     if (process_sp) {
696       process_sp->ReadMemory(process_address, bytes, size, error);
697       if (!error.Success())
698         return;
699     }
700     break;
701   }
702 
703   if (lldb_private::Log *log =
704           lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_EXPRESSIONS)) {
705     log->Printf("IRMemoryMap::ReadMemory (0x%" PRIx64 ", 0x%" PRIx64
706                 ", 0x%" PRId64 ") came from [0x%" PRIx64 "..0x%" PRIx64 ")",
707                 (uint64_t)process_address, (uint64_t)bytes, (uint64_t)size,
708                 (uint64_t)allocation.m_process_start,
709                 (uint64_t)allocation.m_process_start +
710                     (uint64_t)allocation.m_size);
711   }
712 }
713 
714 void IRMemoryMap::ReadScalarFromMemory(Scalar &scalar,
715                                        lldb::addr_t process_address,
716                                        size_t size, Status &error) {
717   error.Clear();
718 
719   if (size > 0) {
720     DataBufferHeap buf(size, 0);
721     ReadMemory(buf.GetBytes(), process_address, size, error);
722 
723     if (!error.Success())
724       return;
725 
726     DataExtractor extractor(buf.GetBytes(), buf.GetByteSize(), GetByteOrder(),
727                             GetAddressByteSize());
728 
729     lldb::offset_t offset = 0;
730 
731     switch (size) {
732     default:
733       error.SetErrorToGenericError();
734       error.SetErrorStringWithFormat(
735           "Couldn't read scalar: unsupported size %" PRIu64, (uint64_t)size);
736       return;
737     case 1:
738       scalar = extractor.GetU8(&offset);
739       break;
740     case 2:
741       scalar = extractor.GetU16(&offset);
742       break;
743     case 4:
744       scalar = extractor.GetU32(&offset);
745       break;
746     case 8:
747       scalar = extractor.GetU64(&offset);
748       break;
749     }
750   } else {
751     error.SetErrorToGenericError();
752     error.SetErrorString("Couldn't read scalar: its size was zero");
753   }
754   return;
755 }
756 
757 void IRMemoryMap::ReadPointerFromMemory(lldb::addr_t *address,
758                                         lldb::addr_t process_address,
759                                         Status &error) {
760   error.Clear();
761 
762   Scalar pointer_scalar;
763   ReadScalarFromMemory(pointer_scalar, process_address, GetAddressByteSize(),
764                        error);
765 
766   if (!error.Success())
767     return;
768 
769   *address = pointer_scalar.ULongLong();
770 
771   return;
772 }
773 
774 void IRMemoryMap::GetMemoryData(DataExtractor &extractor,
775                                 lldb::addr_t process_address, size_t size,
776                                 Status &error) {
777   error.Clear();
778 
779   if (size > 0) {
780     AllocationMap::iterator iter = FindAllocation(process_address, size);
781 
782     if (iter == m_allocations.end()) {
783       error.SetErrorToGenericError();
784       error.SetErrorStringWithFormat(
785           "Couldn't find an allocation containing [0x%" PRIx64 "..0x%" PRIx64
786           ")",
787           process_address, process_address + size);
788       return;
789     }
790 
791     Allocation &allocation = iter->second;
792 
793     switch (allocation.m_policy) {
794     default:
795       error.SetErrorToGenericError();
796       error.SetErrorString(
797           "Couldn't get memory data: invalid allocation policy");
798       return;
799     case eAllocationPolicyProcessOnly:
800       error.SetErrorToGenericError();
801       error.SetErrorString(
802           "Couldn't get memory data: memory is only in the target");
803       return;
804     case eAllocationPolicyMirror: {
805       lldb::ProcessSP process_sp = m_process_wp.lock();
806 
807       if (!allocation.m_data.GetByteSize()) {
808         error.SetErrorToGenericError();
809         error.SetErrorString("Couldn't get memory data: data buffer is empty");
810         return;
811       }
812       if (process_sp) {
813         process_sp->ReadMemory(allocation.m_process_start,
814                                allocation.m_data.GetBytes(),
815                                allocation.m_data.GetByteSize(), error);
816         if (!error.Success())
817           return;
818         uint64_t offset = process_address - allocation.m_process_start;
819         extractor = DataExtractor(allocation.m_data.GetBytes() + offset, size,
820                                   GetByteOrder(), GetAddressByteSize());
821         return;
822       }
823     } break;
824     case eAllocationPolicyHostOnly:
825       if (!allocation.m_data.GetByteSize()) {
826         error.SetErrorToGenericError();
827         error.SetErrorString("Couldn't get memory data: data buffer is empty");
828         return;
829       }
830       uint64_t offset = process_address - allocation.m_process_start;
831       extractor = DataExtractor(allocation.m_data.GetBytes() + offset, size,
832                                 GetByteOrder(), GetAddressByteSize());
833       return;
834     }
835   } else {
836     error.SetErrorToGenericError();
837     error.SetErrorString("Couldn't get memory data: its size was zero");
838     return;
839   }
840 }
841