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
9#include "llvm/ExecutionEngine/JITLink/JITLinkMemoryManager.h"
10#include "llvm/ExecutionEngine/JITLink/JITLink.h"
11#include "llvm/Support/FormatVariadic.h"
12#include "llvm/Support/Process.h"
13
14#define DEBUG_TYPE "jitlink"
15
16using namespace llvm;
17
18namespace llvm {
19namespace jitlink {
20
21JITLinkMemoryManager::~JITLinkMemoryManager() = default;
22JITLinkMemoryManager::InFlightAlloc::~InFlightAlloc() = default;
23
24BasicLayout::BasicLayout(LinkGraph &G) : G(G) {
25
26 for (auto &Sec : G.sections()) {
27 // Skip empty sections, and sections with NoAlloc lifetime policies.
28 if (Sec.blocks().empty() ||
29 Sec.getMemLifetime() == orc::MemLifetime::NoAlloc)
30 continue;
31
32 auto &Seg = Segments[{Sec.getMemProt(), Sec.getMemLifetime()}];
33 for (auto *B : Sec.blocks())
34 if (LLVM_LIKELY(!B->isZeroFill()))
35 Seg.ContentBlocks.push_back(x: B);
36 else
37 Seg.ZeroFillBlocks.push_back(x: B);
38 }
39
40 // Build Segments map.
41 auto CompareBlocks = [](const Block *LHS, const Block *RHS) {
42 // Sort by section, address and size
43 if (LHS->getSection().getOrdinal() != RHS->getSection().getOrdinal())
44 return LHS->getSection().getOrdinal() < RHS->getSection().getOrdinal();
45 if (LHS->getAddress() != RHS->getAddress())
46 return LHS->getAddress() < RHS->getAddress();
47 return LHS->getSize() < RHS->getSize();
48 };
49
50 LLVM_DEBUG(dbgs() << "Generated BasicLayout for " << G.getName() << ":\n");
51 for (auto &KV : Segments) {
52 auto &Seg = KV.second;
53
54 llvm::sort(C&: Seg.ContentBlocks, Comp: CompareBlocks);
55 llvm::sort(C&: Seg.ZeroFillBlocks, Comp: CompareBlocks);
56
57 for (auto *B : Seg.ContentBlocks) {
58 Seg.ContentSize = alignToBlock(Addr: Seg.ContentSize, B: *B);
59 Seg.ContentSize += B->getSize();
60 Seg.Alignment = std::max(a: Seg.Alignment, b: Align(B->getAlignment()));
61 }
62
63 uint64_t SegEndOffset = Seg.ContentSize;
64 for (auto *B : Seg.ZeroFillBlocks) {
65 SegEndOffset = alignToBlock(Addr: SegEndOffset, B: *B);
66 SegEndOffset += B->getSize();
67 Seg.Alignment = std::max(a: Seg.Alignment, b: Align(B->getAlignment()));
68 }
69 Seg.ZeroFillSize = SegEndOffset - Seg.ContentSize;
70
71 LLVM_DEBUG({
72 dbgs() << " Seg " << KV.first
73 << ": content-size=" << formatv("{0:x}", Seg.ContentSize)
74 << ", zero-fill-size=" << formatv("{0:x}", Seg.ZeroFillSize)
75 << ", align=" << formatv("{0:x}", Seg.Alignment.value()) << "\n";
76 });
77 }
78}
79
80Expected<BasicLayout::ContiguousPageBasedLayoutSizes>
81BasicLayout::getContiguousPageBasedLayoutSizes(uint64_t PageSize) {
82 ContiguousPageBasedLayoutSizes SegsSizes;
83
84 for (auto &KV : segments()) {
85 auto &AG = KV.first;
86 auto &Seg = KV.second;
87
88 if (Seg.Alignment > PageSize)
89 return make_error<StringError>(Args: "Segment alignment greater than page size",
90 Args: inconvertibleErrorCode());
91
92 uint64_t SegSize = alignTo(Value: Seg.ContentSize + Seg.ZeroFillSize, Align: PageSize);
93 if (AG.getMemLifetime() == orc::MemLifetime::Standard)
94 SegsSizes.StandardSegs += SegSize;
95 else
96 SegsSizes.FinalizeSegs += SegSize;
97 }
98
99 return SegsSizes;
100}
101
102Error BasicLayout::apply() {
103 for (auto &KV : Segments) {
104 auto &Seg = KV.second;
105
106 assert(!(Seg.ContentBlocks.empty() && Seg.ZeroFillBlocks.empty()) &&
107 "Empty section recorded?");
108
109 for (auto *B : Seg.ContentBlocks) {
110 // Align addr and working-mem-offset.
111 Seg.Addr = alignToBlock(Addr: Seg.Addr, B: *B);
112 Seg.NextWorkingMemOffset = alignToBlock(Addr: Seg.NextWorkingMemOffset, B: *B);
113
114 // Update block addr.
115 B->setAddress(Seg.Addr);
116 Seg.Addr += B->getSize();
117
118 // Copy content to working memory, then update content to point at working
119 // memory.
120 memcpy(dest: Seg.WorkingMem + Seg.NextWorkingMemOffset, src: B->getContent().data(),
121 n: B->getSize());
122 B->setMutableContent(
123 {Seg.WorkingMem + Seg.NextWorkingMemOffset, B->getSize()});
124 Seg.NextWorkingMemOffset += B->getSize();
125 }
126
127 for (auto *B : Seg.ZeroFillBlocks) {
128 // Align addr.
129 Seg.Addr = alignToBlock(Addr: Seg.Addr, B: *B);
130 // Update block addr.
131 B->setAddress(Seg.Addr);
132 Seg.Addr += B->getSize();
133 }
134
135 Seg.ContentBlocks.clear();
136 Seg.ZeroFillBlocks.clear();
137 }
138
139 return Error::success();
140}
141
142orc::shared::AllocActions &BasicLayout::graphAllocActions() {
143 return G.allocActions();
144}
145
146void SimpleSegmentAlloc::Create(JITLinkMemoryManager &MemMgr,
147 std::shared_ptr<orc::SymbolStringPool> SSP,
148 Triple TT, const JITLinkDylib *JD,
149 SegmentMap Segments,
150 OnCreatedFunction OnCreated) {
151
152 static_assert(orc::AllocGroup::NumGroups == 32,
153 "AllocGroup has changed. Section names below must be updated");
154 StringRef AGSectionNames[] = {
155 "__---.standard", "__R--.standard", "__-W-.standard", "__RW-.standard",
156 "__--X.standard", "__R-X.standard", "__-WX.standard", "__RWX.standard",
157 "__---.finalize", "__R--.finalize", "__-W-.finalize", "__RW-.finalize",
158 "__--X.finalize", "__R-X.finalize", "__-WX.finalize", "__RWX.finalize"};
159
160 auto G =
161 std::make_unique<LinkGraph>(args: "", args: std::move(SSP), args: std::move(TT),
162 args: SubtargetFeatures(), args&: getGenericEdgeKindName);
163 orc::AllocGroupSmallMap<Block *> ContentBlocks;
164
165 orc::ExecutorAddr NextAddr(0x100000);
166 for (auto &KV : Segments) {
167 auto &AG = KV.first;
168 auto &Seg = KV.second;
169
170 assert(AG.getMemLifetime() != orc::MemLifetime::NoAlloc &&
171 "NoAlloc segments are not supported by SimpleSegmentAlloc");
172
173 auto AGSectionName =
174 AGSectionNames[static_cast<unsigned>(AG.getMemProt()) |
175 static_cast<bool>(AG.getMemLifetime()) << 3];
176
177 auto &Sec = G->createSection(Name: AGSectionName, Prot: AG.getMemProt());
178 Sec.setMemLifetime(AG.getMemLifetime());
179
180 if (Seg.ContentSize != 0) {
181 NextAddr =
182 orc::ExecutorAddr(alignTo(Size: NextAddr.getValue(), A: Seg.ContentAlign));
183 auto &B =
184 G->createMutableContentBlock(Parent&: Sec, MutableContent: G->allocateBuffer(Size: Seg.ContentSize),
185 Address: NextAddr, Alignment: Seg.ContentAlign.value(), AlignmentOffset: 0);
186 ContentBlocks[AG] = &B;
187 NextAddr += Seg.ContentSize;
188 }
189 }
190
191 // GRef declared separately since order-of-argument-eval isn't specified.
192 auto &GRef = *G;
193 MemMgr.allocate(JD, G&: GRef,
194 OnAllocated: [G = std::move(G), ContentBlocks = std::move(ContentBlocks),
195 OnCreated = std::move(OnCreated)](
196 JITLinkMemoryManager::AllocResult Alloc) mutable {
197 if (!Alloc)
198 OnCreated(Alloc.takeError());
199 else
200 OnCreated(SimpleSegmentAlloc(std::move(G),
201 std::move(ContentBlocks),
202 std::move(*Alloc)));
203 });
204}
205
206Expected<SimpleSegmentAlloc> SimpleSegmentAlloc::Create(
207 JITLinkMemoryManager &MemMgr, std::shared_ptr<orc::SymbolStringPool> SSP,
208 Triple TT, const JITLinkDylib *JD, SegmentMap Segments) {
209 std::promise<MSVCPExpected<SimpleSegmentAlloc>> AllocP;
210 auto AllocF = AllocP.get_future();
211 Create(MemMgr, SSP: std::move(SSP), TT: std::move(TT), JD, Segments: std::move(Segments),
212 OnCreated: [&](Expected<SimpleSegmentAlloc> Result) {
213 AllocP.set_value(std::move(Result));
214 });
215 return AllocF.get();
216}
217
218SimpleSegmentAlloc::SimpleSegmentAlloc(SimpleSegmentAlloc &&) = default;
219SimpleSegmentAlloc &
220SimpleSegmentAlloc::operator=(SimpleSegmentAlloc &&) = default;
221SimpleSegmentAlloc::~SimpleSegmentAlloc() = default;
222
223SimpleSegmentAlloc::SegmentInfo
224SimpleSegmentAlloc::getSegInfo(orc::AllocGroup AG) {
225 auto I = ContentBlocks.find(G: AG);
226 if (I != ContentBlocks.end()) {
227 auto &B = *I->second;
228 return {.Addr: B.getAddress(), .WorkingMem: B.getAlreadyMutableContent()};
229 }
230 return {};
231}
232
233SimpleSegmentAlloc::SimpleSegmentAlloc(
234 std::unique_ptr<LinkGraph> G,
235 orc::AllocGroupSmallMap<Block *> ContentBlocks,
236 std::unique_ptr<JITLinkMemoryManager::InFlightAlloc> Alloc)
237 : G(std::move(G)), ContentBlocks(std::move(ContentBlocks)),
238 Alloc(std::move(Alloc)) {}
239
240class InProcessMemoryManager::IPInFlightAlloc
241 : public JITLinkMemoryManager::InFlightAlloc {
242public:
243 IPInFlightAlloc(InProcessMemoryManager &MemMgr, LinkGraph &G, BasicLayout BL,
244 sys::MemoryBlock StandardSegments,
245 sys::MemoryBlock FinalizationSegments)
246 : MemMgr(MemMgr), G(&G), BL(std::move(BL)),
247 StandardSegments(std::move(StandardSegments)),
248 FinalizationSegments(std::move(FinalizationSegments)) {}
249
250 ~IPInFlightAlloc() override {
251 assert(!G && "InFlight alloc neither abandoned nor finalized");
252 }
253
254 void finalize(OnFinalizedFunction OnFinalized) override {
255
256 // Apply memory protections to all segments.
257 if (auto Err = applyProtections()) {
258 OnFinalized(std::move(Err));
259 return;
260 }
261
262 // Run finalization actions.
263 auto DeallocActions = runFinalizeActions(AAs&: G->allocActions());
264 if (!DeallocActions) {
265 OnFinalized(DeallocActions.takeError());
266 return;
267 }
268
269 // Release the finalize segments slab.
270 if (auto EC = sys::Memory::releaseMappedMemory(Block&: FinalizationSegments)) {
271 OnFinalized(errorCodeToError(EC));
272 return;
273 }
274
275#ifndef NDEBUG
276 // Set 'G' to null to flag that we've been successfully finalized.
277 // This allows us to assert at destruction time that a call has been made
278 // to either finalize or abandon.
279 G = nullptr;
280#endif
281
282 // Continue with finalized allocation.
283 OnFinalized(MemMgr.createFinalizedAlloc(StandardSegments: std::move(StandardSegments),
284 DeallocActions: std::move(*DeallocActions)));
285 }
286
287 void abandon(OnAbandonedFunction OnAbandoned) override {
288 Error Err = Error::success();
289 if (auto EC = sys::Memory::releaseMappedMemory(Block&: FinalizationSegments))
290 Err = joinErrors(E1: std::move(Err), E2: errorCodeToError(EC));
291 if (auto EC = sys::Memory::releaseMappedMemory(Block&: StandardSegments))
292 Err = joinErrors(E1: std::move(Err), E2: errorCodeToError(EC));
293
294#ifndef NDEBUG
295 // Set 'G' to null to flag that we've been successfully finalized.
296 // This allows us to assert at destruction time that a call has been made
297 // to either finalize or abandon.
298 G = nullptr;
299#endif
300
301 OnAbandoned(std::move(Err));
302 }
303
304private:
305 Error applyProtections() {
306 for (auto &KV : BL.segments()) {
307 const auto &AG = KV.first;
308 auto &Seg = KV.second;
309
310 auto Prot = toSysMemoryProtectionFlags(MP: AG.getMemProt());
311
312 uint64_t SegSize =
313 alignTo(Value: Seg.ContentSize + Seg.ZeroFillSize, Align: MemMgr.PageSize);
314 sys::MemoryBlock MB(Seg.WorkingMem, SegSize);
315 if (auto EC = sys::Memory::protectMappedMemory(Block: MB, Flags: Prot))
316 return errorCodeToError(EC);
317 if (Prot & sys::Memory::MF_EXEC)
318 sys::Memory::InvalidateInstructionCache(Addr: MB.base(), Len: MB.allocatedSize());
319 }
320 return Error::success();
321 }
322
323 InProcessMemoryManager &MemMgr;
324 LinkGraph *G;
325 BasicLayout BL;
326 sys::MemoryBlock StandardSegments;
327 sys::MemoryBlock FinalizationSegments;
328};
329
330Expected<std::unique_ptr<InProcessMemoryManager>>
331InProcessMemoryManager::Create() {
332 if (auto PageSize = sys::Process::getPageSize()) {
333 // FIXME: Just check this once on startup.
334 if (!isPowerOf2_64(Value: (uint64_t)*PageSize))
335 return make_error<StringError>(
336 Args: "Could not create InProcessMemoryManager: Page size " +
337 Twine(*PageSize) + " is not a power of 2",
338 Args: inconvertibleErrorCode());
339
340 return std::make_unique<InProcessMemoryManager>(args&: *PageSize);
341 } else
342 return PageSize.takeError();
343}
344
345void InProcessMemoryManager::allocate(const JITLinkDylib *JD, LinkGraph &G,
346 OnAllocatedFunction OnAllocated) {
347 BasicLayout BL(G);
348
349 /// Scan the request and calculate the group and total sizes.
350 /// Check that segment size is no larger than a page.
351 auto SegsSizes = BL.getContiguousPageBasedLayoutSizes(PageSize);
352 if (!SegsSizes) {
353 OnAllocated(SegsSizes.takeError());
354 return;
355 }
356
357 /// Check that the total size requested (including zero fill) is not larger
358 /// than a size_t.
359 if (SegsSizes->total() > std::numeric_limits<size_t>::max()) {
360 OnAllocated(make_error<JITLinkError>(
361 Args: "Total requested size " + formatv(Fmt: "{0:x}", Vals: SegsSizes->total()) +
362 " for graph " + G.getName() + " exceeds address space"));
363 return;
364 }
365
366 // Allocate one slab for the whole thing (to make sure everything is
367 // in-range), then partition into standard and finalization blocks.
368 //
369 // FIXME: Make two separate allocations in the future to reduce
370 // fragmentation: finalization segments will usually be a single page, and
371 // standard segments are likely to be more than one page. Where multiple
372 // allocations are in-flight at once (likely) the current approach will leave
373 // a lot of single-page holes.
374 sys::MemoryBlock Slab;
375 sys::MemoryBlock StandardSegsMem;
376 sys::MemoryBlock FinalizeSegsMem;
377 {
378 const sys::Memory::ProtectionFlags ReadWrite =
379 static_cast<sys::Memory::ProtectionFlags>(sys::Memory::MF_READ |
380 sys::Memory::MF_WRITE);
381
382 std::error_code EC;
383 Slab = sys::Memory::allocateMappedMemory(NumBytes: SegsSizes->total(), NearBlock: nullptr,
384 Flags: ReadWrite, EC);
385
386 if (EC) {
387 OnAllocated(errorCodeToError(EC));
388 return;
389 }
390
391 // Zero-fill the whole slab up-front.
392 memset(s: Slab.base(), c: 0, n: Slab.allocatedSize());
393
394 StandardSegsMem = {Slab.base(),
395 static_cast<size_t>(SegsSizes->StandardSegs)};
396 FinalizeSegsMem = {(void *)((char *)Slab.base() + SegsSizes->StandardSegs),
397 static_cast<size_t>(SegsSizes->FinalizeSegs)};
398 }
399
400 auto NextStandardSegAddr = orc::ExecutorAddr::fromPtr(Ptr: StandardSegsMem.base());
401 auto NextFinalizeSegAddr = orc::ExecutorAddr::fromPtr(Ptr: FinalizeSegsMem.base());
402
403 LLVM_DEBUG({
404 dbgs() << "InProcessMemoryManager allocated:\n";
405 if (SegsSizes->StandardSegs)
406 dbgs() << formatv(" [ {0:x16} -- {1:x16} ]", NextStandardSegAddr,
407 NextStandardSegAddr + StandardSegsMem.allocatedSize())
408 << " to stardard segs\n";
409 else
410 dbgs() << " no standard segs\n";
411 if (SegsSizes->FinalizeSegs)
412 dbgs() << formatv(" [ {0:x16} -- {1:x16} ]", NextFinalizeSegAddr,
413 NextFinalizeSegAddr + FinalizeSegsMem.allocatedSize())
414 << " to finalize segs\n";
415 else
416 dbgs() << " no finalize segs\n";
417 });
418
419 // Build ProtMap, assign addresses.
420 for (auto &KV : BL.segments()) {
421 auto &AG = KV.first;
422 auto &Seg = KV.second;
423
424 auto &SegAddr = (AG.getMemLifetime() == orc::MemLifetime::Standard)
425 ? NextStandardSegAddr
426 : NextFinalizeSegAddr;
427
428 Seg.WorkingMem = SegAddr.toPtr<char *>();
429 Seg.Addr = SegAddr;
430
431 SegAddr += alignTo(Value: Seg.ContentSize + Seg.ZeroFillSize, Align: PageSize);
432 }
433
434 if (auto Err = BL.apply()) {
435 OnAllocated(std::move(Err));
436 return;
437 }
438
439 OnAllocated(std::make_unique<IPInFlightAlloc>(args&: *this, args&: G, args: std::move(BL),
440 args: std::move(StandardSegsMem),
441 args: std::move(FinalizeSegsMem)));
442}
443
444void InProcessMemoryManager::deallocate(std::vector<FinalizedAlloc> Allocs,
445 OnDeallocatedFunction OnDeallocated) {
446 std::vector<sys::MemoryBlock> StandardSegmentsList;
447 std::vector<std::vector<orc::shared::WrapperFunctionCall>> DeallocActionsList;
448
449 {
450 std::lock_guard<std::mutex> Lock(FinalizedAllocsMutex);
451 for (auto &Alloc : Allocs) {
452 auto *FA = Alloc.release().toPtr<FinalizedAllocInfo *>();
453 StandardSegmentsList.push_back(x: std::move(FA->StandardSegments));
454 DeallocActionsList.push_back(x: std::move(FA->DeallocActions));
455 FA->~FinalizedAllocInfo();
456 FinalizedAllocInfos.Deallocate(E: FA);
457 }
458 }
459
460 Error DeallocErr = Error::success();
461
462 while (!DeallocActionsList.empty()) {
463 auto &DeallocActions = DeallocActionsList.back();
464 auto &StandardSegments = StandardSegmentsList.back();
465
466 /// Run any deallocate calls.
467 while (!DeallocActions.empty()) {
468 if (auto Err = DeallocActions.back().runWithSPSRetErrorMerged())
469 DeallocErr = joinErrors(E1: std::move(DeallocErr), E2: std::move(Err));
470 DeallocActions.pop_back();
471 }
472
473 /// Release the standard segments slab.
474 if (auto EC = sys::Memory::releaseMappedMemory(Block&: StandardSegments))
475 DeallocErr = joinErrors(E1: std::move(DeallocErr), E2: errorCodeToError(EC));
476
477 DeallocActionsList.pop_back();
478 StandardSegmentsList.pop_back();
479 }
480
481 OnDeallocated(std::move(DeallocErr));
482}
483
484JITLinkMemoryManager::FinalizedAlloc
485InProcessMemoryManager::createFinalizedAlloc(
486 sys::MemoryBlock StandardSegments,
487 std::vector<orc::shared::WrapperFunctionCall> DeallocActions) {
488 std::lock_guard<std::mutex> Lock(FinalizedAllocsMutex);
489 auto *FA = FinalizedAllocInfos.Allocate<FinalizedAllocInfo>();
490 new (FA) FinalizedAllocInfo(
491 {.StandardSegments: std::move(StandardSegments), .DeallocActions: std::move(DeallocActions)});
492 return FinalizedAlloc(orc::ExecutorAddr::fromPtr(Ptr: FA));
493}
494
495} // end namespace jitlink
496} // end namespace llvm
497