1 //===- FaultMaps.cpp ------------------------------------------------------===// 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/CodeGen/FaultMaps.h" 10 #include "llvm/ADT/Twine.h" 11 #include "llvm/CodeGen/AsmPrinter.h" 12 #include "llvm/MC/MCContext.h" 13 #include "llvm/MC/MCExpr.h" 14 #include "llvm/MC/MCObjectFileInfo.h" 15 #include "llvm/MC/MCStreamer.h" 16 #include "llvm/Support/Debug.h" 17 #include "llvm/Support/ErrorHandling.h" 18 #include "llvm/Support/Format.h" 19 #include "llvm/Support/raw_ostream.h" 20 21 using namespace llvm; 22 23 #define DEBUG_TYPE "faultmaps" 24 25 static const int FaultMapVersion = 1; 26 const char *FaultMaps::WFMP = "Fault Maps: "; 27 28 FaultMaps::FaultMaps(AsmPrinter &AP) : AP(AP) {} 29 30 void FaultMaps::recordFaultingOp(FaultKind FaultTy, 31 const MCSymbol *FaultingLabel, 32 const MCSymbol *HandlerLabel) { 33 MCContext &OutContext = AP.OutStreamer->getContext(); 34 35 const MCExpr *FaultingOffset = MCBinaryExpr::createSub( 36 MCSymbolRefExpr::create(FaultingLabel, OutContext), 37 MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext); 38 39 const MCExpr *HandlerOffset = MCBinaryExpr::createSub( 40 MCSymbolRefExpr::create(HandlerLabel, OutContext), 41 MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext); 42 43 FunctionInfos[AP.CurrentFnSym].emplace_back(FaultTy, FaultingOffset, 44 HandlerOffset); 45 } 46 47 void FaultMaps::serializeToFaultMapSection() { 48 if (FunctionInfos.empty()) 49 return; 50 51 MCContext &OutContext = AP.OutStreamer->getContext(); 52 MCStreamer &OS = *AP.OutStreamer; 53 54 // Create the section. 55 MCSection *FaultMapSection = 56 OutContext.getObjectFileInfo()->getFaultMapSection(); 57 OS.SwitchSection(FaultMapSection); 58 59 // Emit a dummy symbol to force section inclusion. 60 OS.EmitLabel(OutContext.getOrCreateSymbol(Twine("__LLVM_FaultMaps"))); 61 62 LLVM_DEBUG(dbgs() << "********** Fault Map Output **********\n"); 63 64 // Header 65 OS.EmitIntValue(FaultMapVersion, 1); // Version. 66 OS.EmitIntValue(0, 1); // Reserved. 67 OS.EmitIntValue(0, 2); // Reserved. 68 69 LLVM_DEBUG(dbgs() << WFMP << "#functions = " << FunctionInfos.size() << "\n"); 70 OS.EmitIntValue(FunctionInfos.size(), 4); 71 72 LLVM_DEBUG(dbgs() << WFMP << "functions:\n"); 73 74 for (const auto &FFI : FunctionInfos) 75 emitFunctionInfo(FFI.first, FFI.second); 76 } 77 78 void FaultMaps::emitFunctionInfo(const MCSymbol *FnLabel, 79 const FunctionFaultInfos &FFI) { 80 MCStreamer &OS = *AP.OutStreamer; 81 82 LLVM_DEBUG(dbgs() << WFMP << " function addr: " << *FnLabel << "\n"); 83 OS.EmitSymbolValue(FnLabel, 8); 84 85 LLVM_DEBUG(dbgs() << WFMP << " #faulting PCs: " << FFI.size() << "\n"); 86 OS.EmitIntValue(FFI.size(), 4); 87 88 OS.EmitIntValue(0, 4); // Reserved 89 90 for (auto &Fault : FFI) { 91 LLVM_DEBUG(dbgs() << WFMP << " fault type: " 92 << faultTypeToString(Fault.Kind) << "\n"); 93 OS.EmitIntValue(Fault.Kind, 4); 94 95 LLVM_DEBUG(dbgs() << WFMP << " faulting PC offset: " 96 << *Fault.FaultingOffsetExpr << "\n"); 97 OS.EmitValue(Fault.FaultingOffsetExpr, 4); 98 99 LLVM_DEBUG(dbgs() << WFMP << " fault handler PC offset: " 100 << *Fault.HandlerOffsetExpr << "\n"); 101 OS.EmitValue(Fault.HandlerOffsetExpr, 4); 102 } 103 } 104 105 const char *FaultMaps::faultTypeToString(FaultMaps::FaultKind FT) { 106 switch (FT) { 107 default: 108 llvm_unreachable("unhandled fault type!"); 109 case FaultMaps::FaultingLoad: 110 return "FaultingLoad"; 111 case FaultMaps::FaultingLoadStore: 112 return "FaultingLoadStore"; 113 case FaultMaps::FaultingStore: 114 return "FaultingStore"; 115 } 116 } 117 118 raw_ostream &llvm:: 119 operator<<(raw_ostream &OS, 120 const FaultMapParser::FunctionFaultInfoAccessor &FFI) { 121 OS << "Fault kind: " 122 << FaultMaps::faultTypeToString((FaultMaps::FaultKind)FFI.getFaultKind()) 123 << ", faulting PC offset: " << FFI.getFaultingPCOffset() 124 << ", handling PC offset: " << FFI.getHandlerPCOffset(); 125 return OS; 126 } 127 128 raw_ostream &llvm:: 129 operator<<(raw_ostream &OS, const FaultMapParser::FunctionInfoAccessor &FI) { 130 OS << "FunctionAddress: " << format_hex(FI.getFunctionAddr(), 8) 131 << ", NumFaultingPCs: " << FI.getNumFaultingPCs() << "\n"; 132 for (unsigned i = 0, e = FI.getNumFaultingPCs(); i != e; ++i) 133 OS << FI.getFunctionFaultInfoAt(i) << "\n"; 134 return OS; 135 } 136 137 raw_ostream &llvm::operator<<(raw_ostream &OS, const FaultMapParser &FMP) { 138 OS << "Version: " << format_hex(FMP.getFaultMapVersion(), 2) << "\n"; 139 OS << "NumFunctions: " << FMP.getNumFunctions() << "\n"; 140 141 if (FMP.getNumFunctions() == 0) 142 return OS; 143 144 FaultMapParser::FunctionInfoAccessor FI; 145 146 for (unsigned i = 0, e = FMP.getNumFunctions(); i != e; ++i) { 147 FI = (i == 0) ? FMP.getFirstFunctionInfo() : FI.getNextFunctionInfo(); 148 OS << FI; 149 } 150 151 return OS; 152 } 153