LLVM  14.0.0git
JITLinkMemoryManager.cpp
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1 //===--- JITLinkMemoryManager.cpp - JITLinkMemoryManager implementation ---===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
12 #include "llvm/Support/Process.h"
13 
14 #define DEBUG_TYPE "jitlink"
15 
16 using namespace llvm;
17 
18 namespace llvm {
19 namespace jitlink {
20 
23 
25 
26  for (auto &Sec : G.sections()) {
27  // Skip empty sections.
28  if (empty(Sec.blocks()))
29  continue;
30 
31  auto &Seg = Segments[{Sec.getMemProt(), Sec.getMemDeallocPolicy()}];
32  for (auto *B : Sec.blocks())
33  if (LLVM_LIKELY(!B->isZeroFill()))
34  Seg.ContentBlocks.push_back(B);
35  else
36  Seg.ZeroFillBlocks.push_back(B);
37  }
38 
39  // Build Segments map.
40  auto CompareBlocks = [](const Block *LHS, const Block *RHS) {
41  // Sort by section, address and size
42  if (LHS->getSection().getOrdinal() != RHS->getSection().getOrdinal())
43  return LHS->getSection().getOrdinal() < RHS->getSection().getOrdinal();
44  if (LHS->getAddress() != RHS->getAddress())
45  return LHS->getAddress() < RHS->getAddress();
46  return LHS->getSize() < RHS->getSize();
47  };
48 
49  LLVM_DEBUG(dbgs() << "Generated BasicLayout for " << G.getName() << ":\n");
50  for (auto &KV : Segments) {
51  auto &Seg = KV.second;
52 
53  llvm::sort(Seg.ContentBlocks, CompareBlocks);
54  llvm::sort(Seg.ZeroFillBlocks, CompareBlocks);
55 
56  for (auto *B : Seg.ContentBlocks) {
57  Seg.ContentSize = alignToBlock(Seg.ContentSize, *B);
58  Seg.ContentSize += B->getSize();
59  Seg.Alignment = std::max(Seg.Alignment, Align(B->getAlignment()));
60  }
61 
62  uint64_t SegEndOffset = Seg.ContentSize;
63  for (auto *B : Seg.ZeroFillBlocks) {
64  SegEndOffset = alignToBlock(SegEndOffset, *B);
65  SegEndOffset += B->getSize();
66  Seg.Alignment = std::max(Seg.Alignment, Align(B->getAlignment()));
67  }
68  Seg.ZeroFillSize = SegEndOffset - Seg.ContentSize;
69 
70  LLVM_DEBUG({
71  dbgs() << " Seg " << KV.first
72  << ": content-size=" << formatv("{0:x}", Seg.ContentSize)
73  << ", zero-fill-size=" << formatv("{0:x}", Seg.ZeroFillSize)
74  << ", align=" << formatv("{0:x}", Seg.Alignment.value()) << "\n";
75  });
76  }
77 }
78 
82 
83  for (auto &KV : segments()) {
84  auto &AG = KV.first;
85  auto &Seg = KV.second;
86 
87  if (Seg.Alignment > PageSize)
88  return make_error<StringError>("Segment alignment greater than page size",
90 
91  uint64_t SegSize = alignTo(Seg.ContentSize + Seg.ZeroFillSize, PageSize);
92  if (AG.getMemDeallocPolicy() == MemDeallocPolicy::Standard)
93  SegsSizes.StandardSegs += SegSize;
94  else
95  SegsSizes.FinalizeSegs += SegSize;
96  }
97 
98  return SegsSizes;
99 }
100 
102  for (auto &KV : Segments) {
103  auto &Seg = KV.second;
104 
105  assert(!(Seg.ContentBlocks.empty() && Seg.ZeroFillBlocks.empty()) &&
106  "Empty section recorded?");
107 
108  for (auto *B : Seg.ContentBlocks) {
109  // Align addr and working-mem-offset.
110  Seg.Addr = alignToBlock(Seg.Addr, *B);
111  Seg.NextWorkingMemOffset = alignToBlock(Seg.NextWorkingMemOffset, *B);
112 
113  // Update block addr.
114  B->setAddress(Seg.Addr);
115  Seg.Addr += B->getSize();
116 
117  // Copy content to working memory, then update content to point at working
118  // memory.
119  memcpy(Seg.WorkingMem + Seg.NextWorkingMemOffset, B->getContent().data(),
120  B->getSize());
121  B->setMutableContent(
122  {Seg.WorkingMem + Seg.NextWorkingMemOffset, B->getSize()});
123  Seg.NextWorkingMemOffset += B->getSize();
124  }
125 
126  for (auto *B : Seg.ZeroFillBlocks) {
127  // Align addr.
128  Seg.Addr = alignToBlock(Seg.Addr, *B);
129  // Update block addr.
130  B->setAddress(Seg.Addr);
131  Seg.Addr += B->getSize();
132  }
133 
134  Seg.ContentBlocks.clear();
135  Seg.ZeroFillBlocks.clear();
136  }
137 
138  return Error::success();
139 }
140 
142  return G.allocActions();
143 }
144 
146  const JITLinkDylib *JD, SegmentMap Segments,
147  OnCreatedFunction OnCreated) {
148 
149  static_assert(AllocGroup::NumGroups == 16,
150  "AllocGroup has changed. Section names below must be updated");
151  StringRef AGSectionNames[] = {
152  "__---.standard", "__R--.standard", "__-W-.standard", "__RW-.standard",
153  "__--X.standard", "__R-X.standard", "__-WX.standard", "__RWX.standard",
154  "__---.finalize", "__R--.finalize", "__-W-.finalize", "__RW-.finalize",
155  "__--X.finalize", "__R-X.finalize", "__-WX.finalize", "__RWX.finalize"};
156 
157  auto G =
158  std::make_unique<LinkGraph>("", Triple(), 0, support::native, nullptr);
159  AllocGroupSmallMap<Block *> ContentBlocks;
160 
161  orc::ExecutorAddr NextAddr(0x100000);
162  for (auto &KV : Segments) {
163  auto &AG = KV.first;
164  auto &Seg = KV.second;
165 
166  auto AGSectionName =
167  AGSectionNames[static_cast<unsigned>(AG.getMemProt()) |
168  static_cast<bool>(AG.getMemDeallocPolicy()) << 3];
169 
170  auto &Sec = G->createSection(AGSectionName, AG.getMemProt());
171  Sec.setMemDeallocPolicy(AG.getMemDeallocPolicy());
172 
173  if (Seg.ContentSize != 0) {
174  NextAddr =
175  orc::ExecutorAddr(alignTo(NextAddr.getValue(), Seg.ContentAlign));
176  auto &B =
177  G->createMutableContentBlock(Sec, G->allocateBuffer(Seg.ContentSize),
178  NextAddr, Seg.ContentAlign.value(), 0);
179  ContentBlocks[AG] = &B;
180  NextAddr += Seg.ContentSize;
181  }
182  }
183 
184  // GRef declared separately since order-of-argument-eval isn't specified.
185  auto &GRef = *G;
186  MemMgr.allocate(JD, GRef,
187  [G = std::move(G), ContentBlocks = std::move(ContentBlocks),
188  OnCreated = std::move(OnCreated)](
189  JITLinkMemoryManager::AllocResult Alloc) mutable {
190  if (!Alloc)
191  OnCreated(Alloc.takeError());
192  else
193  OnCreated(SimpleSegmentAlloc(std::move(G),
194  std::move(ContentBlocks),
195  std::move(*Alloc)));
196  });
197 }
198 
201  SegmentMap Segments) {
202  std::promise<MSVCPExpected<SimpleSegmentAlloc>> AllocP;
203  auto AllocF = AllocP.get_future();
204  Create(MemMgr, JD, std::move(Segments),
205  [&](Expected<SimpleSegmentAlloc> Result) {
206  AllocP.set_value(std::move(Result));
207  });
208  return AllocF.get();
209 }
210 
215 
217  auto I = ContentBlocks.find(AG);
218  if (I != ContentBlocks.end()) {
219  auto &B = *I->second;
220  return {B.getAddress(), B.getAlreadyMutableContent()};
221  }
222  return {};
223 }
224 
226  std::unique_ptr<LinkGraph> G, AllocGroupSmallMap<Block *> ContentBlocks,
227  std::unique_ptr<JITLinkMemoryManager::InFlightAlloc> Alloc)
228  : G(std::move(G)), ContentBlocks(std::move(ContentBlocks)),
229  Alloc(std::move(Alloc)) {}
230 
233 public:
235  sys::MemoryBlock StandardSegments,
236  sys::MemoryBlock FinalizationSegments)
237  : MemMgr(MemMgr), G(G), BL(std::move(BL)),
238  StandardSegments(std::move(StandardSegments)),
239  FinalizationSegments(std::move(FinalizationSegments)) {}
240 
241  void finalize(OnFinalizedFunction OnFinalized) override {
242 
243  // Apply memory protections to all segments.
244  if (auto Err = applyProtections()) {
245  OnFinalized(std::move(Err));
246  return;
247  }
248 
249  // Run finalization actions.
250  auto DeallocActions = runFinalizeActions(G.allocActions());
251  if (!DeallocActions) {
252  OnFinalized(DeallocActions.takeError());
253  return;
254  }
255 
256  // Release the finalize segments slab.
257  if (auto EC = sys::Memory::releaseMappedMemory(FinalizationSegments)) {
258  OnFinalized(errorCodeToError(EC));
259  return;
260  }
261 
262  // Continue with finalized allocation.
263  OnFinalized(MemMgr.createFinalizedAlloc(std::move(StandardSegments),
264  std::move(*DeallocActions)));
265  }
266 
267  void abandon(OnAbandonedFunction OnAbandoned) override {
268  Error Err = Error::success();
269  if (auto EC = sys::Memory::releaseMappedMemory(FinalizationSegments))
270  Err = joinErrors(std::move(Err), errorCodeToError(EC));
271  if (auto EC = sys::Memory::releaseMappedMemory(StandardSegments))
272  Err = joinErrors(std::move(Err), errorCodeToError(EC));
273  OnAbandoned(std::move(Err));
274  }
275 
276 private:
277  Error applyProtections() {
278  for (auto &KV : BL.segments()) {
279  const auto &AG = KV.first;
280  auto &Seg = KV.second;
281 
282  auto Prot = toSysMemoryProtectionFlags(AG.getMemProt());
283 
284  uint64_t SegSize =
285  alignTo(Seg.ContentSize + Seg.ZeroFillSize, MemMgr.PageSize);
286  sys::MemoryBlock MB(Seg.WorkingMem, SegSize);
287  if (auto EC = sys::Memory::protectMappedMemory(MB, Prot))
288  return errorCodeToError(EC);
289  if (Prot & sys::Memory::MF_EXEC)
290  sys::Memory::InvalidateInstructionCache(MB.base(), MB.allocatedSize());
291  }
292  return Error::success();
293  }
294 
295  InProcessMemoryManager &MemMgr;
296  LinkGraph &G;
297  BasicLayout BL;
298  sys::MemoryBlock StandardSegments;
299  sys::MemoryBlock FinalizationSegments;
300 };
301 
304  if (auto PageSize = sys::Process::getPageSize())
305  return std::make_unique<InProcessMemoryManager>(*PageSize);
306  else
307  return PageSize.takeError();
308 }
309 
311  OnAllocatedFunction OnAllocated) {
312 
313  // FIXME: Just check this once on startup.
314  if (!isPowerOf2_64((uint64_t)PageSize)) {
315  OnAllocated(make_error<StringError>("Page size is not a power of 2",
317  return;
318  }
319 
320  BasicLayout BL(G);
321 
322  /// Scan the request and calculate the group and total sizes.
323  /// Check that segment size is no larger than a page.
324  auto SegsSizes = BL.getContiguousPageBasedLayoutSizes(PageSize);
325  if (!SegsSizes) {
326  OnAllocated(SegsSizes.takeError());
327  return;
328  }
329 
330  /// Check that the total size requested (including zero fill) is not larger
331  /// than a size_t.
332  if (SegsSizes->total() > std::numeric_limits<size_t>::max()) {
333  OnAllocated(make_error<JITLinkError>(
334  "Total requested size " + formatv("{0:x}", SegsSizes->total()) +
335  " for graph " + G.getName() + " exceeds address space"));
336  return;
337  }
338 
339  // Allocate one slab for the whole thing (to make sure everything is
340  // in-range), then partition into standard and finalization blocks.
341  //
342  // FIXME: Make two separate allocations in the future to reduce
343  // fragmentation: finalization segments will usually be a single page, and
344  // standard segments are likely to be more than one page. Where multiple
345  // allocations are in-flight at once (likely) the current approach will leave
346  // a lot of single-page holes.
347  sys::MemoryBlock Slab;
348  sys::MemoryBlock StandardSegsMem;
349  sys::MemoryBlock FinalizeSegsMem;
350  {
351  const sys::Memory::ProtectionFlags ReadWrite =
354 
355  std::error_code EC;
356  Slab = sys::Memory::allocateMappedMemory(SegsSizes->total(), nullptr,
357  ReadWrite, EC);
358 
359  if (EC) {
360  OnAllocated(errorCodeToError(EC));
361  return;
362  }
363 
364  // Zero-fill the whole slab up-front.
365  memset(Slab.base(), 0, Slab.allocatedSize());
366 
367  StandardSegsMem = {Slab.base(),
368  static_cast<size_t>(SegsSizes->StandardSegs)};
369  FinalizeSegsMem = {(void *)((char *)Slab.base() + SegsSizes->StandardSegs),
370  static_cast<size_t>(SegsSizes->FinalizeSegs)};
371  }
372 
373  auto NextStandardSegAddr = orc::ExecutorAddr::fromPtr(StandardSegsMem.base());
374  auto NextFinalizeSegAddr = orc::ExecutorAddr::fromPtr(FinalizeSegsMem.base());
375 
376  LLVM_DEBUG({
377  dbgs() << "InProcessMemoryManager allocated:\n";
378  if (SegsSizes->StandardSegs)
379  dbgs() << formatv(" [ {0:x16} -- {1:x16} ]", NextStandardSegAddr,
380  NextStandardSegAddr + StandardSegsMem.allocatedSize())
381  << " to stardard segs\n";
382  else
383  dbgs() << " no standard segs\n";
384  if (SegsSizes->FinalizeSegs)
385  dbgs() << formatv(" [ {0:x16} -- {1:x16} ]", NextFinalizeSegAddr,
386  NextFinalizeSegAddr + FinalizeSegsMem.allocatedSize())
387  << " to finalize segs\n";
388  else
389  dbgs() << " no finalize segs\n";
390  });
391 
392  // Build ProtMap, assign addresses.
393  for (auto &KV : BL.segments()) {
394  auto &AG = KV.first;
395  auto &Seg = KV.second;
396 
397  auto &SegAddr = (AG.getMemDeallocPolicy() == MemDeallocPolicy::Standard)
398  ? NextStandardSegAddr
399  : NextFinalizeSegAddr;
400 
401  Seg.WorkingMem = SegAddr.toPtr<char *>();
402  Seg.Addr = SegAddr;
403 
404  SegAddr += alignTo(Seg.ContentSize + Seg.ZeroFillSize, PageSize);
405  }
406 
407  if (auto Err = BL.apply()) {
408  OnAllocated(std::move(Err));
409  return;
410  }
411 
412  OnAllocated(std::make_unique<IPInFlightAlloc>(*this, G, std::move(BL),
413  std::move(StandardSegsMem),
414  std::move(FinalizeSegsMem)));
415 }
416 
417 void InProcessMemoryManager::deallocate(std::vector<FinalizedAlloc> Allocs,
418  OnDeallocatedFunction OnDeallocated) {
419  std::vector<sys::MemoryBlock> StandardSegmentsList;
420  std::vector<std::vector<orc::shared::WrapperFunctionCall>> DeallocActionsList;
421 
422  {
423  std::lock_guard<std::mutex> Lock(FinalizedAllocsMutex);
424  for (auto &Alloc : Allocs) {
425  auto *FA = Alloc.release().toPtr<FinalizedAllocInfo *>();
426  StandardSegmentsList.push_back(std::move(FA->StandardSegments));
427  if (!FA->DeallocActions.empty())
428  DeallocActionsList.push_back(std::move(FA->DeallocActions));
429  FA->~FinalizedAllocInfo();
430  FinalizedAllocInfos.Deallocate(FA);
431  }
432  }
433 
434  Error DeallocErr = Error::success();
435 
436  while (!DeallocActionsList.empty()) {
437  auto &DeallocActions = DeallocActionsList.back();
438  auto &StandardSegments = StandardSegmentsList.back();
439 
440  /// Run any deallocate calls.
441  while (!DeallocActions.empty()) {
442  if (auto Err = DeallocActions.back().runWithSPSRetErrorMerged())
443  DeallocErr = joinErrors(std::move(DeallocErr), std::move(Err));
444  DeallocActions.pop_back();
445  }
446 
447  /// Release the standard segments slab.
448  if (auto EC = sys::Memory::releaseMappedMemory(StandardSegments))
449  DeallocErr = joinErrors(std::move(DeallocErr), errorCodeToError(EC));
450 
451  DeallocActionsList.pop_back();
452  StandardSegmentsList.pop_back();
453  }
454 
455  OnDeallocated(std::move(DeallocErr));
456 }
457 
459 InProcessMemoryManager::createFinalizedAlloc(
460  sys::MemoryBlock StandardSegments,
461  std::vector<orc::shared::WrapperFunctionCall> DeallocActions) {
462  std::lock_guard<std::mutex> Lock(FinalizedAllocsMutex);
463  auto *FA = FinalizedAllocInfos.Allocate<FinalizedAllocInfo>();
464  new (FA) FinalizedAllocInfo(
465  {std::move(StandardSegments), std::move(DeallocActions)});
466  return FinalizedAlloc(orc::ExecutorAddr::fromPtr(FA));
467 }
468 
469 } // end namespace jitlink
470 } // end namespace llvm
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