xref: /llvm-project/llvm/lib/ExecutionEngine/Orc/EPCIndirectionUtils.cpp (revision e50aea58d59c8cfae807a7fee21c4227472c0678)
1 //===------- EPCIndirectionUtils.cpp -- EPC based indirection APIs --------===//
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 
9 #include "llvm/ExecutionEngine/Orc/EPCIndirectionUtils.h"
10 
11 #include "llvm/ExecutionEngine/Orc/ExecutorProcessControl.h"
12 #include "llvm/Support/MathExtras.h"
13 
14 #include <future>
15 
16 using namespace llvm;
17 using namespace llvm::orc;
18 
19 namespace llvm {
20 namespace orc {
21 
22 class EPCIndirectionUtilsAccess {
23 public:
24   using IndirectStubInfo = EPCIndirectionUtils::IndirectStubInfo;
25   using IndirectStubInfoVector = EPCIndirectionUtils::IndirectStubInfoVector;
26 
27   static Expected<IndirectStubInfoVector>
28   getIndirectStubs(EPCIndirectionUtils &EPCIU, unsigned NumStubs) {
29     return EPCIU.getIndirectStubs(NumStubs);
30   };
31 };
32 
33 } // end namespace orc
34 } // end namespace llvm
35 
36 namespace {
37 
38 class EPCTrampolinePool : public TrampolinePool {
39 public:
40   EPCTrampolinePool(EPCIndirectionUtils &EPCIU);
41   Error deallocatePool();
42 
43 protected:
44   Error grow() override;
45 
46   using FinalizedAlloc = jitlink::JITLinkMemoryManager::FinalizedAlloc;
47 
48   EPCIndirectionUtils &EPCIU;
49   unsigned TrampolineSize = 0;
50   unsigned TrampolinesPerPage = 0;
51   std::vector<FinalizedAlloc> TrampolineBlocks;
52 };
53 
54 class EPCIndirectStubsManager : public IndirectStubsManager,
55                                 private EPCIndirectionUtilsAccess {
56 public:
57   EPCIndirectStubsManager(EPCIndirectionUtils &EPCIU) : EPCIU(EPCIU) {}
58 
59   Error deallocateStubs();
60 
61   Error createStub(StringRef StubName, JITTargetAddress StubAddr,
62                    JITSymbolFlags StubFlags) override;
63 
64   Error createStubs(const StubInitsMap &StubInits) override;
65 
66   JITEvaluatedSymbol findStub(StringRef Name, bool ExportedStubsOnly) override;
67 
68   JITEvaluatedSymbol findPointer(StringRef Name) override;
69 
70   Error updatePointer(StringRef Name, JITTargetAddress NewAddr) override;
71 
72 private:
73   using StubInfo = std::pair<IndirectStubInfo, JITSymbolFlags>;
74 
75   std::mutex ISMMutex;
76   EPCIndirectionUtils &EPCIU;
77   StringMap<StubInfo> StubInfos;
78 };
79 
80 EPCTrampolinePool::EPCTrampolinePool(EPCIndirectionUtils &EPCIU)
81     : EPCIU(EPCIU) {
82   auto &EPC = EPCIU.getExecutorProcessControl();
83   auto &ABI = EPCIU.getABISupport();
84 
85   TrampolineSize = ABI.getTrampolineSize();
86   TrampolinesPerPage =
87       (EPC.getPageSize() - ABI.getPointerSize()) / TrampolineSize;
88 }
89 
90 Error EPCTrampolinePool::deallocatePool() {
91   Error Err = Error::success();
92   std::promise<MSVCPError> DeallocResultP;
93   auto DeallocResultF = DeallocResultP.get_future();
94 
95   EPCIU.getExecutorProcessControl().getMemMgr().deallocate(
96       std::move(TrampolineBlocks),
97       [&](Error Err) { DeallocResultP.set_value(std::move(Err)); });
98 
99   return DeallocResultF.get();
100 }
101 
102 Error EPCTrampolinePool::grow() {
103   using namespace jitlink;
104 
105   assert(AvailableTrampolines.empty() &&
106          "Grow called with trampolines still available");
107 
108   auto ResolverAddress = EPCIU.getResolverBlockAddress();
109   assert(ResolverAddress && "Resolver address can not be null");
110 
111   auto &EPC = EPCIU.getExecutorProcessControl();
112   auto PageSize = EPC.getPageSize();
113   auto Alloc = SimpleSegmentAlloc::Create(
114       EPC.getMemMgr(), nullptr,
115       {{MemProt::Read | MemProt::Exec, {PageSize, Align(PageSize)}}});
116   if (!Alloc)
117     return Alloc.takeError();
118 
119   unsigned NumTrampolines = TrampolinesPerPage;
120 
121   auto SegInfo = Alloc->getSegInfo(MemProt::Read | MemProt::Exec);
122   EPCIU.getABISupport().writeTrampolines(
123       SegInfo.WorkingMem.data(), SegInfo.Addr, ResolverAddress, NumTrampolines);
124   for (unsigned I = 0; I < NumTrampolines; ++I)
125     AvailableTrampolines.push_back(SegInfo.Addr + (I * TrampolineSize));
126 
127   auto FA = Alloc->finalize();
128   if (!FA)
129     return FA.takeError();
130 
131   TrampolineBlocks.push_back(std::move(*FA));
132 
133   return Error::success();
134 }
135 
136 Error EPCIndirectStubsManager::createStub(StringRef StubName,
137                                           JITTargetAddress StubAddr,
138                                           JITSymbolFlags StubFlags) {
139   StubInitsMap SIM;
140   SIM[StubName] = std::make_pair(StubAddr, StubFlags);
141   return createStubs(SIM);
142 }
143 
144 Error EPCIndirectStubsManager::createStubs(const StubInitsMap &StubInits) {
145   auto AvailableStubInfos = getIndirectStubs(EPCIU, StubInits.size());
146   if (!AvailableStubInfos)
147     return AvailableStubInfos.takeError();
148 
149   {
150     std::lock_guard<std::mutex> Lock(ISMMutex);
151     unsigned ASIdx = 0;
152     for (auto &SI : StubInits) {
153       auto &A = (*AvailableStubInfos)[ASIdx++];
154       StubInfos[SI.first()] = std::make_pair(A, SI.second.second);
155     }
156   }
157 
158   auto &MemAccess = EPCIU.getExecutorProcessControl().getMemoryAccess();
159   switch (EPCIU.getABISupport().getPointerSize()) {
160   case 4: {
161     unsigned ASIdx = 0;
162     std::vector<tpctypes::UInt32Write> PtrUpdates;
163     for (auto &SI : StubInits)
164       PtrUpdates.push_back({(*AvailableStubInfos)[ASIdx++].PointerAddress,
165                             static_cast<uint32_t>(SI.second.first)});
166     return MemAccess.writeUInt32s(PtrUpdates);
167   }
168   case 8: {
169     unsigned ASIdx = 0;
170     std::vector<tpctypes::UInt64Write> PtrUpdates;
171     for (auto &SI : StubInits)
172       PtrUpdates.push_back({(*AvailableStubInfos)[ASIdx++].PointerAddress,
173                             static_cast<uint64_t>(SI.second.first)});
174     return MemAccess.writeUInt64s(PtrUpdates);
175   }
176   default:
177     return make_error<StringError>("Unsupported pointer size",
178                                    inconvertibleErrorCode());
179   }
180 }
181 
182 JITEvaluatedSymbol EPCIndirectStubsManager::findStub(StringRef Name,
183                                                      bool ExportedStubsOnly) {
184   std::lock_guard<std::mutex> Lock(ISMMutex);
185   auto I = StubInfos.find(Name);
186   if (I == StubInfos.end())
187     return nullptr;
188   return {I->second.first.StubAddress, I->second.second};
189 }
190 
191 JITEvaluatedSymbol EPCIndirectStubsManager::findPointer(StringRef Name) {
192   std::lock_guard<std::mutex> Lock(ISMMutex);
193   auto I = StubInfos.find(Name);
194   if (I == StubInfos.end())
195     return nullptr;
196   return {I->second.first.PointerAddress, I->second.second};
197 }
198 
199 Error EPCIndirectStubsManager::updatePointer(StringRef Name,
200                                              JITTargetAddress NewAddr) {
201 
202   JITTargetAddress PtrAddr = 0;
203   {
204     std::lock_guard<std::mutex> Lock(ISMMutex);
205     auto I = StubInfos.find(Name);
206     if (I == StubInfos.end())
207       return make_error<StringError>("Unknown stub name",
208                                      inconvertibleErrorCode());
209     PtrAddr = I->second.first.PointerAddress;
210   }
211 
212   auto &MemAccess = EPCIU.getExecutorProcessControl().getMemoryAccess();
213   switch (EPCIU.getABISupport().getPointerSize()) {
214   case 4: {
215     tpctypes::UInt32Write PUpdate(PtrAddr, NewAddr);
216     return MemAccess.writeUInt32s(PUpdate);
217   }
218   case 8: {
219     tpctypes::UInt64Write PUpdate(PtrAddr, NewAddr);
220     return MemAccess.writeUInt64s(PUpdate);
221   }
222   default:
223     return make_error<StringError>("Unsupported pointer size",
224                                    inconvertibleErrorCode());
225   }
226 }
227 
228 } // end anonymous namespace.
229 
230 namespace llvm {
231 namespace orc {
232 
233 EPCIndirectionUtils::ABISupport::~ABISupport() {}
234 
235 Expected<std::unique_ptr<EPCIndirectionUtils>>
236 EPCIndirectionUtils::Create(ExecutorProcessControl &EPC) {
237   const auto &TT = EPC.getTargetTriple();
238   switch (TT.getArch()) {
239   default:
240     return make_error<StringError>(
241         std::string("No EPCIndirectionUtils available for ") + TT.str(),
242         inconvertibleErrorCode());
243   case Triple::aarch64:
244   case Triple::aarch64_32:
245     return CreateWithABI<OrcAArch64>(EPC);
246 
247   case Triple::x86:
248     return CreateWithABI<OrcI386>(EPC);
249 
250   case Triple::mips:
251     return CreateWithABI<OrcMips32Be>(EPC);
252 
253   case Triple::mipsel:
254     return CreateWithABI<OrcMips32Le>(EPC);
255 
256   case Triple::mips64:
257   case Triple::mips64el:
258     return CreateWithABI<OrcMips64>(EPC);
259 
260   case Triple::x86_64:
261     if (TT.getOS() == Triple::OSType::Win32)
262       return CreateWithABI<OrcX86_64_Win32>(EPC);
263     else
264       return CreateWithABI<OrcX86_64_SysV>(EPC);
265   }
266 }
267 
268 Error EPCIndirectionUtils::cleanup() {
269 
270   auto &MemMgr = EPC.getMemMgr();
271   auto Err = MemMgr.deallocate(std::move(IndirectStubAllocs));
272 
273   if (TP)
274     Err = joinErrors(std::move(Err),
275                      static_cast<EPCTrampolinePool &>(*TP).deallocatePool());
276 
277   if (ResolverBlock)
278     Err =
279         joinErrors(std::move(Err), MemMgr.deallocate(std::move(ResolverBlock)));
280 
281   return Err;
282 }
283 
284 Expected<JITTargetAddress>
285 EPCIndirectionUtils::writeResolverBlock(JITTargetAddress ReentryFnAddr,
286                                         JITTargetAddress ReentryCtxAddr) {
287   using namespace jitlink;
288 
289   assert(ABI && "ABI can not be null");
290   auto ResolverSize = ABI->getResolverCodeSize();
291 
292   auto Alloc =
293       SimpleSegmentAlloc::Create(EPC.getMemMgr(), nullptr,
294                                  {{MemProt::Read | MemProt::Exec,
295                                    {ResolverSize, Align(EPC.getPageSize())}}});
296 
297   if (!Alloc)
298     return Alloc.takeError();
299 
300   auto SegInfo = Alloc->getSegInfo(MemProt::Read | MemProt::Exec);
301   ABI->writeResolverCode(SegInfo.WorkingMem.data(), SegInfo.Addr, ReentryFnAddr,
302                          ReentryCtxAddr);
303 
304   auto FA = Alloc->finalize();
305   if (!FA)
306     return FA.takeError();
307 
308   ResolverBlock = std::move(*FA);
309   return SegInfo.Addr;
310 }
311 
312 std::unique_ptr<IndirectStubsManager>
313 EPCIndirectionUtils::createIndirectStubsManager() {
314   return std::make_unique<EPCIndirectStubsManager>(*this);
315 }
316 
317 TrampolinePool &EPCIndirectionUtils::getTrampolinePool() {
318   if (!TP)
319     TP = std::make_unique<EPCTrampolinePool>(*this);
320   return *TP;
321 }
322 
323 LazyCallThroughManager &EPCIndirectionUtils::createLazyCallThroughManager(
324     ExecutionSession &ES, JITTargetAddress ErrorHandlerAddr) {
325   assert(!LCTM &&
326          "createLazyCallThroughManager can not have been called before");
327   LCTM = std::make_unique<LazyCallThroughManager>(ES, ErrorHandlerAddr,
328                                                   &getTrampolinePool());
329   return *LCTM;
330 }
331 
332 EPCIndirectionUtils::EPCIndirectionUtils(ExecutorProcessControl &EPC,
333                                          std::unique_ptr<ABISupport> ABI)
334     : EPC(EPC), ABI(std::move(ABI)) {
335   assert(this->ABI && "ABI can not be null");
336 
337   assert(EPC.getPageSize() > getABISupport().getStubSize() &&
338          "Stubs larger than one page are not supported");
339 }
340 
341 Expected<EPCIndirectionUtils::IndirectStubInfoVector>
342 EPCIndirectionUtils::getIndirectStubs(unsigned NumStubs) {
343   using namespace jitlink;
344 
345   std::lock_guard<std::mutex> Lock(EPCUIMutex);
346 
347   // If there aren't enough stubs available then allocate some more.
348   if (NumStubs > AvailableIndirectStubs.size()) {
349     auto NumStubsToAllocate = NumStubs;
350     auto PageSize = EPC.getPageSize();
351     auto StubBytes = alignTo(NumStubsToAllocate * ABI->getStubSize(), PageSize);
352     NumStubsToAllocate = StubBytes / ABI->getStubSize();
353     auto PtrBytes =
354         alignTo(NumStubsToAllocate * ABI->getPointerSize(), PageSize);
355 
356     auto StubProt = MemProt::Read | MemProt::Exec;
357     auto PtrProt = MemProt::Read | MemProt::Write;
358 
359     auto Alloc = SimpleSegmentAlloc::Create(
360         EPC.getMemMgr(), nullptr,
361         {{StubProt, {static_cast<size_t>(StubBytes), Align(PageSize)}},
362          {PtrProt, {PtrBytes, Align(PageSize)}}});
363 
364     if (!Alloc)
365       return Alloc.takeError();
366 
367     auto StubSeg = Alloc->getSegInfo(StubProt);
368     auto PtrSeg = Alloc->getSegInfo(PtrProt);
369 
370     ABI->writeIndirectStubsBlock(StubSeg.WorkingMem.data(), StubSeg.Addr,
371                                  PtrSeg.Addr, NumStubsToAllocate);
372 
373     auto FA = Alloc->finalize();
374     if (!FA)
375       return FA.takeError();
376 
377     IndirectStubAllocs.push_back(std::move(*FA));
378 
379     auto StubExecutorAddr = StubSeg.Addr;
380     auto PtrExecutorAddr = PtrSeg.Addr;
381     for (unsigned I = 0; I != NumStubsToAllocate; ++I) {
382       AvailableIndirectStubs.push_back(
383           IndirectStubInfo(StubExecutorAddr, PtrExecutorAddr));
384       StubExecutorAddr += ABI->getStubSize();
385       PtrExecutorAddr += ABI->getPointerSize();
386     }
387   }
388 
389   assert(NumStubs <= AvailableIndirectStubs.size() &&
390          "Sufficient stubs should have been allocated above");
391 
392   IndirectStubInfoVector Result;
393   while (NumStubs--) {
394     Result.push_back(AvailableIndirectStubs.back());
395     AvailableIndirectStubs.pop_back();
396   }
397 
398   return std::move(Result);
399 }
400 
401 static JITTargetAddress reentry(JITTargetAddress LCTMAddr,
402                                 JITTargetAddress TrampolineAddr) {
403   auto &LCTM = *jitTargetAddressToPointer<LazyCallThroughManager *>(LCTMAddr);
404   std::promise<JITTargetAddress> LandingAddrP;
405   auto LandingAddrF = LandingAddrP.get_future();
406   LCTM.resolveTrampolineLandingAddress(
407       TrampolineAddr,
408       [&](JITTargetAddress Addr) { LandingAddrP.set_value(Addr); });
409   return LandingAddrF.get();
410 }
411 
412 Error setUpInProcessLCTMReentryViaEPCIU(EPCIndirectionUtils &EPCIU) {
413   auto &LCTM = EPCIU.getLazyCallThroughManager();
414   return EPCIU
415       .writeResolverBlock(pointerToJITTargetAddress(&reentry),
416                           pointerToJITTargetAddress(&LCTM))
417       .takeError();
418 }
419 
420 } // end namespace orc
421 } // end namespace llvm
422