84fe1f63b0
The find-dynamic-unwind-info callback registration APIs in libunwind limit the number of callbacks that can be registered. If we use multiple UnwindInfoManager instances, each with their own own callback function (as was the case prior to this patch) we can quickly exceed this limit (see https://github.com/llvm/llvm-project/issues/126611). This patch updates the UnwindInfoManager class to use a singleton pattern, with the single instance shared between all LLVM JITs in the process. This change does _not_ apply to compact unwind info registered through the ORC runtime (which currently installs its own callbacks). As a bonus this change eliminates the need to load an IR "bouncer" module to supply the unique callback for each instance, so support for compact-unwind can be extended to the llvm-jitlink tools (which does not support adding IR).
125 lines
4.4 KiB
C++
125 lines
4.4 KiB
C++
//===----- UnwindInfoRegistrationPlugin.cpp - libunwind registration ------===//
|
|
//
|
|
// 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/UnwindInfoRegistrationPlugin.h"
|
|
|
|
#include "llvm/ADT/ScopeExit.h"
|
|
#include "llvm/ExecutionEngine/Orc/Shared/MachOObjectFormat.h"
|
|
#include "llvm/ExecutionEngine/Orc/Shared/OrcRTBridge.h"
|
|
#include "llvm/IR/IRBuilder.h"
|
|
#include "llvm/IR/Module.h"
|
|
|
|
#define DEBUG_TYPE "orc"
|
|
|
|
using namespace llvm::jitlink;
|
|
|
|
namespace llvm::orc {
|
|
|
|
Expected<std::shared_ptr<UnwindInfoRegistrationPlugin>>
|
|
UnwindInfoRegistrationPlugin::Create(ExecutionSession &ES) {
|
|
|
|
ExecutorAddr Register, Deregister;
|
|
|
|
auto &EPC = ES.getExecutorProcessControl();
|
|
if (auto Err = EPC.getBootstrapSymbols(
|
|
{{Register, rt_alt::UnwindInfoManagerRegisterActionName},
|
|
{Deregister, rt_alt::UnwindInfoManagerDeregisterActionName}}))
|
|
return std::move(Err);
|
|
|
|
return std::make_shared<UnwindInfoRegistrationPlugin>(ES, Register,
|
|
Deregister);
|
|
}
|
|
|
|
void UnwindInfoRegistrationPlugin::modifyPassConfig(
|
|
MaterializationResponsibility &MR, LinkGraph &G,
|
|
PassConfiguration &PassConfig) {
|
|
|
|
PassConfig.PostFixupPasses.push_back(
|
|
[this](LinkGraph &G) { return addUnwindInfoRegistrationActions(G); });
|
|
}
|
|
|
|
Error UnwindInfoRegistrationPlugin::addUnwindInfoRegistrationActions(
|
|
LinkGraph &G) {
|
|
ExecutorAddrRange EHFrameRange, UnwindInfoRange;
|
|
|
|
std::vector<Block *> CodeBlocks;
|
|
|
|
auto ScanUnwindInfoSection = [&](Section &Sec, ExecutorAddrRange &SecRange) {
|
|
if (Sec.empty())
|
|
return;
|
|
|
|
SecRange.Start = (*Sec.blocks().begin())->getAddress();
|
|
for (auto *B : Sec.blocks()) {
|
|
auto R = B->getRange();
|
|
SecRange.Start = std::min(SecRange.Start, R.Start);
|
|
SecRange.End = std::max(SecRange.End, R.End);
|
|
for (auto &E : B->edges()) {
|
|
if (E.getKind() != Edge::KeepAlive || !E.getTarget().isDefined())
|
|
continue;
|
|
auto &TargetBlock = E.getTarget().getBlock();
|
|
auto &TargetSection = TargetBlock.getSection();
|
|
if ((TargetSection.getMemProt() & MemProt::Exec) == MemProt::Exec)
|
|
CodeBlocks.push_back(&TargetBlock);
|
|
}
|
|
}
|
|
};
|
|
|
|
if (auto *EHFrame = G.findSectionByName(MachOEHFrameSectionName))
|
|
ScanUnwindInfoSection(*EHFrame, EHFrameRange);
|
|
|
|
if (auto *UnwindInfo = G.findSectionByName(MachOUnwindInfoSectionName))
|
|
ScanUnwindInfoSection(*UnwindInfo, UnwindInfoRange);
|
|
|
|
if (CodeBlocks.empty())
|
|
return Error::success();
|
|
|
|
if ((EHFrameRange == ExecutorAddrRange() &&
|
|
UnwindInfoRange == ExecutorAddrRange()))
|
|
return Error::success();
|
|
|
|
llvm::sort(CodeBlocks, [](const Block *LHS, const Block *RHS) {
|
|
return LHS->getAddress() < RHS->getAddress();
|
|
});
|
|
|
|
SmallVector<ExecutorAddrRange> CodeRanges;
|
|
for (auto *B : CodeBlocks) {
|
|
if (CodeRanges.empty() || CodeRanges.back().End != B->getAddress())
|
|
CodeRanges.push_back(B->getRange());
|
|
else
|
|
CodeRanges.back().End = B->getRange().End;
|
|
}
|
|
|
|
ExecutorAddr DSOBase;
|
|
if (auto *DSOBaseSym = G.findAbsoluteSymbolByName(DSOBaseName))
|
|
DSOBase = DSOBaseSym->getAddress();
|
|
else if (auto *DSOBaseSym = G.findExternalSymbolByName(DSOBaseName))
|
|
DSOBase = DSOBaseSym->getAddress();
|
|
else if (auto *DSOBaseSym = G.findDefinedSymbolByName(DSOBaseName))
|
|
DSOBase = DSOBaseSym->getAddress();
|
|
else
|
|
return make_error<StringError>("In " + G.getName() +
|
|
" could not find dso base symbol",
|
|
inconvertibleErrorCode());
|
|
|
|
using namespace shared;
|
|
using SPSRegisterArgs =
|
|
SPSArgList<SPSSequence<SPSExecutorAddrRange>, SPSExecutorAddr,
|
|
SPSExecutorAddrRange, SPSExecutorAddrRange>;
|
|
using SPSDeregisterArgs = SPSArgList<SPSSequence<SPSExecutorAddrRange>>;
|
|
|
|
G.allocActions().push_back(
|
|
{cantFail(WrapperFunctionCall::Create<SPSRegisterArgs>(
|
|
Register, CodeRanges, DSOBase, EHFrameRange, UnwindInfoRange)),
|
|
cantFail(WrapperFunctionCall::Create<SPSDeregisterArgs>(Deregister,
|
|
CodeRanges))});
|
|
|
|
return Error::success();
|
|
}
|
|
|
|
} // namespace llvm::orc
|