llvm-project/llvm/lib/ExecutionEngine/Orc/ELFNixPlatform.cpp
Lang Hames 9eb4939b86 [ORC] Allow JITDylib::getDFSLinkOrder and friends to fail for defunct JITDylibs.
Calls to JITDylib's getDFSLinkOrder and getReverseDFSLinkOrder methods (both
static an non-static versions) are now valid to make on defunct JITDylibs, but
will return an error if any JITDylib in the link order is defunct.

This means that platforms can safely lookup link orders by name in response to
jit-dlopen calls from the ORC runtime, even if the call names a defunct
JITDylib -- the call will just fail with an error.
2022-01-20 17:45:32 +11:00

829 lines
28 KiB
C++

//===------ ELFNixPlatform.cpp - Utilities for executing MachO in Orc -----===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ExecutionEngine/Orc/ELFNixPlatform.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/ExecutionEngine/JITLink/ELF_x86_64.h"
#include "llvm/ExecutionEngine/JITLink/x86_64.h"
#include "llvm/ExecutionEngine/Orc/DebugUtils.h"
#include "llvm/ExecutionEngine/Orc/ExecutionUtils.h"
#include "llvm/Support/BinaryByteStream.h"
#include "llvm/Support/Debug.h"
#define DEBUG_TYPE "orc"
using namespace llvm;
using namespace llvm::orc;
using namespace llvm::orc::shared;
namespace {
class DSOHandleMaterializationUnit : public MaterializationUnit {
public:
DSOHandleMaterializationUnit(ELFNixPlatform &ENP,
const SymbolStringPtr &DSOHandleSymbol)
: MaterializationUnit(
createDSOHandleSectionInterface(ENP, DSOHandleSymbol)),
ENP(ENP) {}
StringRef getName() const override { return "DSOHandleMU"; }
void materialize(std::unique_ptr<MaterializationResponsibility> R) override {
unsigned PointerSize;
support::endianness Endianness;
jitlink::Edge::Kind EdgeKind;
const auto &TT =
ENP.getExecutionSession().getExecutorProcessControl().getTargetTriple();
switch (TT.getArch()) {
case Triple::x86_64:
PointerSize = 8;
Endianness = support::endianness::little;
EdgeKind = jitlink::x86_64::Pointer64;
break;
default:
llvm_unreachable("Unrecognized architecture");
}
// void *__dso_handle = &__dso_handle;
auto G = std::make_unique<jitlink::LinkGraph>(
"<DSOHandleMU>", TT, PointerSize, Endianness,
jitlink::getGenericEdgeKindName);
auto &DSOHandleSection =
G->createSection(".data.__dso_handle", jitlink::MemProt::Read);
auto &DSOHandleBlock = G->createContentBlock(
DSOHandleSection, getDSOHandleContent(PointerSize), orc::ExecutorAddr(),
8, 0);
auto &DSOHandleSymbol = G->addDefinedSymbol(
DSOHandleBlock, 0, *R->getInitializerSymbol(), DSOHandleBlock.getSize(),
jitlink::Linkage::Strong, jitlink::Scope::Default, false, true);
DSOHandleBlock.addEdge(EdgeKind, 0, DSOHandleSymbol, 0);
ENP.getObjectLinkingLayer().emit(std::move(R), std::move(G));
}
void discard(const JITDylib &JD, const SymbolStringPtr &Sym) override {}
private:
static MaterializationUnit::Interface
createDSOHandleSectionInterface(ELFNixPlatform &ENP,
const SymbolStringPtr &DSOHandleSymbol) {
SymbolFlagsMap SymbolFlags;
SymbolFlags[DSOHandleSymbol] = JITSymbolFlags::Exported;
return MaterializationUnit::Interface(std::move(SymbolFlags),
DSOHandleSymbol);
}
ArrayRef<char> getDSOHandleContent(size_t PointerSize) {
static const char Content[8] = {0};
assert(PointerSize <= sizeof Content);
return {Content, PointerSize};
}
ELFNixPlatform &ENP;
};
StringRef EHFrameSectionName = ".eh_frame";
StringRef InitArrayFuncSectionName = ".init_array";
StringRef ThreadBSSSectionName = ".tbss";
StringRef ThreadDataSectionName = ".tdata";
StringRef InitSectionNames[] = {InitArrayFuncSectionName};
} // end anonymous namespace
namespace llvm {
namespace orc {
Expected<std::unique_ptr<ELFNixPlatform>>
ELFNixPlatform::Create(ExecutionSession &ES,
ObjectLinkingLayer &ObjLinkingLayer,
JITDylib &PlatformJD, const char *OrcRuntimePath,
Optional<SymbolAliasMap> RuntimeAliases) {
auto &EPC = ES.getExecutorProcessControl();
// If the target is not supported then bail out immediately.
if (!supportedTarget(EPC.getTargetTriple()))
return make_error<StringError>("Unsupported ELFNixPlatform triple: " +
EPC.getTargetTriple().str(),
inconvertibleErrorCode());
// Create default aliases if the caller didn't supply any.
if (!RuntimeAliases)
RuntimeAliases = standardPlatformAliases(ES);
// Define the aliases.
if (auto Err = PlatformJD.define(symbolAliases(std::move(*RuntimeAliases))))
return std::move(Err);
// Add JIT-dispatch function support symbols.
if (auto Err = PlatformJD.define(absoluteSymbols(
{{ES.intern("__orc_rt_jit_dispatch"),
{EPC.getJITDispatchInfo().JITDispatchFunction.getValue(),
JITSymbolFlags::Exported}},
{ES.intern("__orc_rt_jit_dispatch_ctx"),
{EPC.getJITDispatchInfo().JITDispatchContext.getValue(),
JITSymbolFlags::Exported}}})))
return std::move(Err);
// Create a generator for the ORC runtime archive.
auto OrcRuntimeArchiveGenerator = StaticLibraryDefinitionGenerator::Load(
ObjLinkingLayer, OrcRuntimePath, EPC.getTargetTriple());
if (!OrcRuntimeArchiveGenerator)
return OrcRuntimeArchiveGenerator.takeError();
// Create the instance.
Error Err = Error::success();
auto P = std::unique_ptr<ELFNixPlatform>(
new ELFNixPlatform(ES, ObjLinkingLayer, PlatformJD,
std::move(*OrcRuntimeArchiveGenerator), Err));
if (Err)
return std::move(Err);
return std::move(P);
}
Error ELFNixPlatform::setupJITDylib(JITDylib &JD) {
return JD.define(
std::make_unique<DSOHandleMaterializationUnit>(*this, DSOHandleSymbol));
}
Error ELFNixPlatform::teardownJITDylib(JITDylib &JD) {
return Error::success();
}
Error ELFNixPlatform::notifyAdding(ResourceTracker &RT,
const MaterializationUnit &MU) {
auto &JD = RT.getJITDylib();
const auto &InitSym = MU.getInitializerSymbol();
if (!InitSym)
return Error::success();
RegisteredInitSymbols[&JD].add(InitSym,
SymbolLookupFlags::WeaklyReferencedSymbol);
LLVM_DEBUG({
dbgs() << "ELFNixPlatform: Registered init symbol " << *InitSym
<< " for MU " << MU.getName() << "\n";
});
return Error::success();
}
Error ELFNixPlatform::notifyRemoving(ResourceTracker &RT) {
llvm_unreachable("Not supported yet");
}
static void addAliases(ExecutionSession &ES, SymbolAliasMap &Aliases,
ArrayRef<std::pair<const char *, const char *>> AL) {
for (auto &KV : AL) {
auto AliasName = ES.intern(KV.first);
assert(!Aliases.count(AliasName) && "Duplicate symbol name in alias map");
Aliases[std::move(AliasName)] = {ES.intern(KV.second),
JITSymbolFlags::Exported};
}
}
SymbolAliasMap ELFNixPlatform::standardPlatformAliases(ExecutionSession &ES) {
SymbolAliasMap Aliases;
addAliases(ES, Aliases, requiredCXXAliases());
addAliases(ES, Aliases, standardRuntimeUtilityAliases());
return Aliases;
}
ArrayRef<std::pair<const char *, const char *>>
ELFNixPlatform::requiredCXXAliases() {
static const std::pair<const char *, const char *> RequiredCXXAliases[] = {
{"__cxa_atexit", "__orc_rt_elfnix_cxa_atexit"},
{"atexit", "__orc_rt_elfnix_atexit"}};
return ArrayRef<std::pair<const char *, const char *>>(RequiredCXXAliases);
}
ArrayRef<std::pair<const char *, const char *>>
ELFNixPlatform::standardRuntimeUtilityAliases() {
static const std::pair<const char *, const char *>
StandardRuntimeUtilityAliases[] = {
{"__orc_rt_run_program", "__orc_rt_elfnix_run_program"},
{"__orc_rt_log_error", "__orc_rt_log_error_to_stderr"}};
return ArrayRef<std::pair<const char *, const char *>>(
StandardRuntimeUtilityAliases);
}
bool ELFNixPlatform::isInitializerSection(StringRef SecName) {
for (auto &Name : InitSectionNames) {
if (Name.equals(SecName))
return true;
}
return false;
}
bool ELFNixPlatform::supportedTarget(const Triple &TT) {
switch (TT.getArch()) {
case Triple::x86_64:
return true;
default:
return false;
}
}
ELFNixPlatform::ELFNixPlatform(
ExecutionSession &ES, ObjectLinkingLayer &ObjLinkingLayer,
JITDylib &PlatformJD,
std::unique_ptr<DefinitionGenerator> OrcRuntimeGenerator, Error &Err)
: ES(ES), ObjLinkingLayer(ObjLinkingLayer),
DSOHandleSymbol(ES.intern("__dso_handle")) {
ErrorAsOutParameter _(&Err);
ObjLinkingLayer.addPlugin(std::make_unique<ELFNixPlatformPlugin>(*this));
PlatformJD.addGenerator(std::move(OrcRuntimeGenerator));
// PlatformJD hasn't been 'set-up' by the platform yet (since we're creating
// the platform now), so set it up.
if (auto E2 = setupJITDylib(PlatformJD)) {
Err = std::move(E2);
return;
}
RegisteredInitSymbols[&PlatformJD].add(
DSOHandleSymbol, SymbolLookupFlags::WeaklyReferencedSymbol);
// Associate wrapper function tags with JIT-side function implementations.
if (auto E2 = associateRuntimeSupportFunctions(PlatformJD)) {
Err = std::move(E2);
return;
}
// Lookup addresses of runtime functions callable by the platform,
// call the platform bootstrap function to initialize the platform-state
// object in the executor.
if (auto E2 = bootstrapELFNixRuntime(PlatformJD)) {
Err = std::move(E2);
return;
}
}
Error ELFNixPlatform::associateRuntimeSupportFunctions(JITDylib &PlatformJD) {
ExecutionSession::JITDispatchHandlerAssociationMap WFs;
using GetInitializersSPSSig =
SPSExpected<SPSELFNixJITDylibInitializerSequence>(SPSString);
WFs[ES.intern("__orc_rt_elfnix_get_initializers_tag")] =
ES.wrapAsyncWithSPS<GetInitializersSPSSig>(
this, &ELFNixPlatform::rt_getInitializers);
using GetDeinitializersSPSSig =
SPSExpected<SPSELFJITDylibDeinitializerSequence>(SPSExecutorAddr);
WFs[ES.intern("__orc_rt_elfnix_get_deinitializers_tag")] =
ES.wrapAsyncWithSPS<GetDeinitializersSPSSig>(
this, &ELFNixPlatform::rt_getDeinitializers);
using LookupSymbolSPSSig =
SPSExpected<SPSExecutorAddr>(SPSExecutorAddr, SPSString);
WFs[ES.intern("__orc_rt_elfnix_symbol_lookup_tag")] =
ES.wrapAsyncWithSPS<LookupSymbolSPSSig>(this,
&ELFNixPlatform::rt_lookupSymbol);
return ES.registerJITDispatchHandlers(PlatformJD, std::move(WFs));
}
void ELFNixPlatform::getInitializersBuildSequencePhase(
SendInitializerSequenceFn SendResult, JITDylib &JD,
std::vector<JITDylibSP> DFSLinkOrder) {
ELFNixJITDylibInitializerSequence FullInitSeq;
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
for (auto &InitJD : reverse(DFSLinkOrder)) {
LLVM_DEBUG({
dbgs() << "ELFNixPlatform: Appending inits for \"" << InitJD->getName()
<< "\" to sequence\n";
});
auto ISItr = InitSeqs.find(InitJD.get());
if (ISItr != InitSeqs.end()) {
FullInitSeq.emplace_back(std::move(ISItr->second));
InitSeqs.erase(ISItr);
}
}
}
SendResult(std::move(FullInitSeq));
}
void ELFNixPlatform::getInitializersLookupPhase(
SendInitializerSequenceFn SendResult, JITDylib &JD) {
auto DFSLinkOrder = JD.getDFSLinkOrder();
if (!DFSLinkOrder) {
SendResult(DFSLinkOrder.takeError());
return;
}
DenseMap<JITDylib *, SymbolLookupSet> NewInitSymbols;
ES.runSessionLocked([&]() {
for (auto &InitJD : *DFSLinkOrder) {
auto RISItr = RegisteredInitSymbols.find(InitJD.get());
if (RISItr != RegisteredInitSymbols.end()) {
NewInitSymbols[InitJD.get()] = std::move(RISItr->second);
RegisteredInitSymbols.erase(RISItr);
}
}
});
// If there are no further init symbols to look up then move on to the next
// phase.
if (NewInitSymbols.empty()) {
getInitializersBuildSequencePhase(std::move(SendResult), JD,
std::move(*DFSLinkOrder));
return;
}
// Otherwise issue a lookup and re-run this phase when it completes.
lookupInitSymbolsAsync(
[this, SendResult = std::move(SendResult), &JD](Error Err) mutable {
if (Err)
SendResult(std::move(Err));
else
getInitializersLookupPhase(std::move(SendResult), JD);
},
ES, std::move(NewInitSymbols));
}
void ELFNixPlatform::rt_getInitializers(SendInitializerSequenceFn SendResult,
StringRef JDName) {
LLVM_DEBUG({
dbgs() << "ELFNixPlatform::rt_getInitializers(\"" << JDName << "\")\n";
});
JITDylib *JD = ES.getJITDylibByName(JDName);
if (!JD) {
LLVM_DEBUG({
dbgs() << " No such JITDylib \"" << JDName << "\". Sending error.\n";
});
SendResult(make_error<StringError>("No JITDylib named " + JDName,
inconvertibleErrorCode()));
return;
}
getInitializersLookupPhase(std::move(SendResult), *JD);
}
void ELFNixPlatform::rt_getDeinitializers(
SendDeinitializerSequenceFn SendResult, ExecutorAddr Handle) {
LLVM_DEBUG({
dbgs() << "ELFNixPlatform::rt_getDeinitializers(\""
<< formatv("{0:x}", Handle.getValue()) << "\")\n";
});
JITDylib *JD = nullptr;
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
auto I = HandleAddrToJITDylib.find(Handle);
if (I != HandleAddrToJITDylib.end())
JD = I->second;
}
if (!JD) {
LLVM_DEBUG({
dbgs() << " No JITDylib for handle "
<< formatv("{0:x}", Handle.getValue()) << "\n";
});
SendResult(make_error<StringError>("No JITDylib associated with handle " +
formatv("{0:x}", Handle.getValue()),
inconvertibleErrorCode()));
return;
}
SendResult(ELFNixJITDylibDeinitializerSequence());
}
void ELFNixPlatform::rt_lookupSymbol(SendSymbolAddressFn SendResult,
ExecutorAddr Handle,
StringRef SymbolName) {
LLVM_DEBUG({
dbgs() << "ELFNixPlatform::rt_lookupSymbol(\""
<< formatv("{0:x}", Handle.getValue()) << "\")\n";
});
JITDylib *JD = nullptr;
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
auto I = HandleAddrToJITDylib.find(Handle);
if (I != HandleAddrToJITDylib.end())
JD = I->second;
}
if (!JD) {
LLVM_DEBUG({
dbgs() << " No JITDylib for handle "
<< formatv("{0:x}", Handle.getValue()) << "\n";
});
SendResult(make_error<StringError>("No JITDylib associated with handle " +
formatv("{0:x}", Handle.getValue()),
inconvertibleErrorCode()));
return;
}
// Use functor class to work around XL build compiler issue on AIX.
class RtLookupNotifyComplete {
public:
RtLookupNotifyComplete(SendSymbolAddressFn &&SendResult)
: SendResult(std::move(SendResult)) {}
void operator()(Expected<SymbolMap> Result) {
if (Result) {
assert(Result->size() == 1 && "Unexpected result map count");
SendResult(ExecutorAddr(Result->begin()->second.getAddress()));
} else {
SendResult(Result.takeError());
}
}
private:
SendSymbolAddressFn SendResult;
};
ES.lookup(
LookupKind::DLSym, {{JD, JITDylibLookupFlags::MatchExportedSymbolsOnly}},
SymbolLookupSet(ES.intern(SymbolName)), SymbolState::Ready,
RtLookupNotifyComplete(std::move(SendResult)), NoDependenciesToRegister);
}
Error ELFNixPlatform::bootstrapELFNixRuntime(JITDylib &PlatformJD) {
std::pair<const char *, ExecutorAddr *> Symbols[] = {
{"__orc_rt_elfnix_platform_bootstrap", &orc_rt_elfnix_platform_bootstrap},
{"__orc_rt_elfnix_platform_shutdown", &orc_rt_elfnix_platform_shutdown},
{"__orc_rt_elfnix_register_object_sections",
&orc_rt_elfnix_register_object_sections},
{"__orc_rt_elfnix_create_pthread_key",
&orc_rt_elfnix_create_pthread_key}};
SymbolLookupSet RuntimeSymbols;
std::vector<std::pair<SymbolStringPtr, ExecutorAddr *>> AddrsToRecord;
for (const auto &KV : Symbols) {
auto Name = ES.intern(KV.first);
RuntimeSymbols.add(Name);
AddrsToRecord.push_back({std::move(Name), KV.second});
}
auto RuntimeSymbolAddrs = ES.lookup(
{{&PlatformJD, JITDylibLookupFlags::MatchAllSymbols}}, RuntimeSymbols);
if (!RuntimeSymbolAddrs)
return RuntimeSymbolAddrs.takeError();
for (const auto &KV : AddrsToRecord) {
auto &Name = KV.first;
assert(RuntimeSymbolAddrs->count(Name) && "Missing runtime symbol?");
KV.second->setValue((*RuntimeSymbolAddrs)[Name].getAddress());
}
auto PJDDSOHandle = ES.lookup(
{{&PlatformJD, JITDylibLookupFlags::MatchAllSymbols}}, DSOHandleSymbol);
if (!PJDDSOHandle)
return PJDDSOHandle.takeError();
if (auto Err = ES.callSPSWrapper<void(uint64_t)>(
orc_rt_elfnix_platform_bootstrap, PJDDSOHandle->getAddress()))
return Err;
// FIXME: Ordering is fuzzy here. We're probably best off saying
// "behavior is undefined if code that uses the runtime is added before
// the platform constructor returns", then move all this to the constructor.
RuntimeBootstrapped = true;
std::vector<ELFPerObjectSectionsToRegister> DeferredPOSRs;
{
std::lock_guard<std::mutex> Lock(PlatformMutex);
DeferredPOSRs = std::move(BootstrapPOSRs);
}
for (auto &D : DeferredPOSRs)
if (auto Err = registerPerObjectSections(D))
return Err;
return Error::success();
}
Error ELFNixPlatform::registerInitInfo(
JITDylib &JD, ArrayRef<jitlink::Section *> InitSections) {
std::unique_lock<std::mutex> Lock(PlatformMutex);
ELFNixJITDylibInitializers *InitSeq = nullptr;
{
auto I = InitSeqs.find(&JD);
if (I == InitSeqs.end()) {
// If there's no init sequence entry yet then we need to look up the
// header symbol to force creation of one.
Lock.unlock();
auto SearchOrder =
JD.withLinkOrderDo([](const JITDylibSearchOrder &SO) { return SO; });
if (auto Err = ES.lookup(SearchOrder, DSOHandleSymbol).takeError())
return Err;
Lock.lock();
I = InitSeqs.find(&JD);
assert(I != InitSeqs.end() &&
"Entry missing after header symbol lookup?");
}
InitSeq = &I->second;
}
for (auto *Sec : InitSections) {
// FIXME: Avoid copy here.
jitlink::SectionRange R(*Sec);
InitSeq->InitSections[Sec->getName()].push_back(
{ExecutorAddr(R.getStart()), ExecutorAddr(R.getEnd())});
}
return Error::success();
}
Error ELFNixPlatform::registerPerObjectSections(
const ELFPerObjectSectionsToRegister &POSR) {
if (!orc_rt_elfnix_register_object_sections)
return make_error<StringError>("Attempting to register per-object "
"sections, but runtime support has not "
"been loaded yet",
inconvertibleErrorCode());
Error ErrResult = Error::success();
if (auto Err = ES.callSPSWrapper<shared::SPSError(
SPSELFPerObjectSectionsToRegister)>(
orc_rt_elfnix_register_object_sections, ErrResult, POSR))
return Err;
return ErrResult;
}
Expected<uint64_t> ELFNixPlatform::createPThreadKey() {
if (!orc_rt_elfnix_create_pthread_key)
return make_error<StringError>(
"Attempting to create pthread key in target, but runtime support has "
"not been loaded yet",
inconvertibleErrorCode());
Expected<uint64_t> Result(0);
if (auto Err = ES.callSPSWrapper<SPSExpected<uint64_t>(void)>(
orc_rt_elfnix_create_pthread_key, Result))
return std::move(Err);
return Result;
}
void ELFNixPlatform::ELFNixPlatformPlugin::modifyPassConfig(
MaterializationResponsibility &MR, jitlink::LinkGraph &LG,
jitlink::PassConfiguration &Config) {
// If the initializer symbol is the __dso_handle symbol then just add
// the DSO handle support passes.
if (MR.getInitializerSymbol() == MP.DSOHandleSymbol) {
addDSOHandleSupportPasses(MR, Config);
// The DSOHandle materialization unit doesn't require any other
// support, so we can bail out early.
return;
}
// If the object contains initializers then add passes to record them.
if (MR.getInitializerSymbol())
addInitializerSupportPasses(MR, Config);
// Add passes for eh-frame and TLV support.
addEHAndTLVSupportPasses(MR, Config);
}
ObjectLinkingLayer::Plugin::SyntheticSymbolDependenciesMap
ELFNixPlatform::ELFNixPlatformPlugin::getSyntheticSymbolDependencies(
MaterializationResponsibility &MR) {
std::lock_guard<std::mutex> Lock(PluginMutex);
auto I = InitSymbolDeps.find(&MR);
if (I != InitSymbolDeps.end()) {
SyntheticSymbolDependenciesMap Result;
Result[MR.getInitializerSymbol()] = std::move(I->second);
InitSymbolDeps.erase(&MR);
return Result;
}
return SyntheticSymbolDependenciesMap();
}
void ELFNixPlatform::ELFNixPlatformPlugin::addInitializerSupportPasses(
MaterializationResponsibility &MR, jitlink::PassConfiguration &Config) {
/// Preserve init sections.
Config.PrePrunePasses.push_back([this, &MR](jitlink::LinkGraph &G) -> Error {
if (auto Err = preserveInitSections(G, MR))
return Err;
return Error::success();
});
Config.PostFixupPasses.push_back(
[this, &JD = MR.getTargetJITDylib()](jitlink::LinkGraph &G) {
return registerInitSections(G, JD);
});
}
void ELFNixPlatform::ELFNixPlatformPlugin::addDSOHandleSupportPasses(
MaterializationResponsibility &MR, jitlink::PassConfiguration &Config) {
Config.PostAllocationPasses.push_back([this, &JD = MR.getTargetJITDylib()](
jitlink::LinkGraph &G) -> Error {
auto I = llvm::find_if(G.defined_symbols(), [this](jitlink::Symbol *Sym) {
return Sym->getName() == *MP.DSOHandleSymbol;
});
assert(I != G.defined_symbols().end() && "Missing DSO handle symbol");
{
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
auto HandleAddr = (*I)->getAddress();
MP.HandleAddrToJITDylib[HandleAddr] = &JD;
assert(!MP.InitSeqs.count(&JD) && "InitSeq entry for JD already exists");
MP.InitSeqs.insert(std::make_pair(
&JD, ELFNixJITDylibInitializers(JD.getName(), HandleAddr)));
}
return Error::success();
});
}
void ELFNixPlatform::ELFNixPlatformPlugin::addEHAndTLVSupportPasses(
MaterializationResponsibility &MR, jitlink::PassConfiguration &Config) {
// Insert TLV lowering at the start of the PostPrunePasses, since we want
// it to run before GOT/PLT lowering.
// TODO: Check that before the fixTLVSectionsAndEdges pass, the GOT/PLT build
// pass has done. Because the TLS descriptor need to be allocate in GOT.
Config.PostPrunePasses.push_back(
[this, &JD = MR.getTargetJITDylib()](jitlink::LinkGraph &G) {
return fixTLVSectionsAndEdges(G, JD);
});
// Add a pass to register the final addresses of the eh-frame and TLV sections
// with the runtime.
Config.PostFixupPasses.push_back([this](jitlink::LinkGraph &G) -> Error {
ELFPerObjectSectionsToRegister POSR;
if (auto *EHFrameSection = G.findSectionByName(EHFrameSectionName)) {
jitlink::SectionRange R(*EHFrameSection);
if (!R.empty())
POSR.EHFrameSection = {ExecutorAddr(R.getStart()),
ExecutorAddr(R.getEnd())};
}
// Get a pointer to the thread data section if there is one. It will be used
// below.
jitlink::Section *ThreadDataSection =
G.findSectionByName(ThreadDataSectionName);
// Handle thread BSS section if there is one.
if (auto *ThreadBSSSection = G.findSectionByName(ThreadBSSSectionName)) {
// If there's already a thread data section in this graph then merge the
// thread BSS section content into it, otherwise just treat the thread
// BSS section as the thread data section.
if (ThreadDataSection)
G.mergeSections(*ThreadDataSection, *ThreadBSSSection);
else
ThreadDataSection = ThreadBSSSection;
}
// Having merged thread BSS (if present) and thread data (if present),
// record the resulting section range.
if (ThreadDataSection) {
jitlink::SectionRange R(*ThreadDataSection);
if (!R.empty())
POSR.ThreadDataSection = {ExecutorAddr(R.getStart()),
ExecutorAddr(R.getEnd())};
}
if (POSR.EHFrameSection.Start || POSR.ThreadDataSection.Start) {
// If we're still bootstrapping the runtime then just record this
// frame for now.
if (!MP.RuntimeBootstrapped) {
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
MP.BootstrapPOSRs.push_back(POSR);
return Error::success();
}
// Otherwise register it immediately.
if (auto Err = MP.registerPerObjectSections(POSR))
return Err;
}
return Error::success();
});
}
Error ELFNixPlatform::ELFNixPlatformPlugin::preserveInitSections(
jitlink::LinkGraph &G, MaterializationResponsibility &MR) {
JITLinkSymbolSet InitSectionSymbols;
for (auto &InitSectionName : InitSectionNames) {
// Skip non-init sections.
auto *InitSection = G.findSectionByName(InitSectionName);
if (!InitSection)
continue;
// Make a pass over live symbols in the section: those blocks are already
// preserved.
DenseSet<jitlink::Block *> AlreadyLiveBlocks;
for (auto &Sym : InitSection->symbols()) {
auto &B = Sym->getBlock();
if (Sym->isLive() && Sym->getOffset() == 0 &&
Sym->getSize() == B.getSize() && !AlreadyLiveBlocks.count(&B)) {
InitSectionSymbols.insert(Sym);
AlreadyLiveBlocks.insert(&B);
}
}
// Add anonymous symbols to preserve any not-already-preserved blocks.
for (auto *B : InitSection->blocks())
if (!AlreadyLiveBlocks.count(B))
InitSectionSymbols.insert(
&G.addAnonymousSymbol(*B, 0, B->getSize(), false, true));
}
if (!InitSectionSymbols.empty()) {
std::lock_guard<std::mutex> Lock(PluginMutex);
InitSymbolDeps[&MR] = std::move(InitSectionSymbols);
}
return Error::success();
}
Error ELFNixPlatform::ELFNixPlatformPlugin::registerInitSections(
jitlink::LinkGraph &G, JITDylib &JD) {
SmallVector<jitlink::Section *> InitSections;
LLVM_DEBUG({ dbgs() << "ELFNixPlatform::registerInitSections\n"; });
for (auto InitSectionName : InitSectionNames) {
if (auto *Sec = G.findSectionByName(InitSectionName)) {
InitSections.push_back(Sec);
}
}
// Dump the scraped inits.
LLVM_DEBUG({
dbgs() << "ELFNixPlatform: Scraped " << G.getName() << " init sections:\n";
for (auto *Sec : InitSections) {
jitlink::SectionRange R(*Sec);
dbgs() << " " << Sec->getName() << ": "
<< formatv("[ {0:x} -- {1:x} ]", R.getStart(), R.getEnd()) << "\n";
}
});
return MP.registerInitInfo(JD, InitSections);
}
Error ELFNixPlatform::ELFNixPlatformPlugin::fixTLVSectionsAndEdges(
jitlink::LinkGraph &G, JITDylib &JD) {
// TODO implement TLV support
for (auto *Sym : G.external_symbols())
if (Sym->getName() == "__tls_get_addr") {
Sym->setName("___orc_rt_elfnix_tls_get_addr");
}
auto *TLSInfoEntrySection = G.findSectionByName("$__TLSINFO");
if (TLSInfoEntrySection) {
Optional<uint64_t> Key;
{
std::lock_guard<std::mutex> Lock(MP.PlatformMutex);
auto I = MP.JITDylibToPThreadKey.find(&JD);
if (I != MP.JITDylibToPThreadKey.end())
Key = I->second;
}
if (!Key) {
if (auto KeyOrErr = MP.createPThreadKey())
Key = *KeyOrErr;
else
return KeyOrErr.takeError();
}
uint64_t PlatformKeyBits =
support::endian::byte_swap(*Key, G.getEndianness());
for (auto *B : TLSInfoEntrySection->blocks()) {
// FIXME: The TLS descriptor byte length may different with different
// ISA
assert(B->getSize() == (G.getPointerSize() * 2) &&
"TLS descriptor must be 2 words length");
auto TLSInfoEntryContent = B->getMutableContent(G);
memcpy(TLSInfoEntryContent.data(), &PlatformKeyBits, G.getPointerSize());
}
}
return Error::success();
}
} // End namespace orc.
} // End namespace llvm.