SanitizerCoverage.cpp | Explore in Territory

//===-- SanitizerCoverage.cpp - coverage instrumentation for sanitizers ---===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Coverage instrumentation done on LLVM IR level, works with Sanitizers.
//
//===----------------------------------------------------------------------===//

#include "llvm/Transforms/Instrumentation/SanitizerCoverage.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/PostDominators.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/EHPersonalities.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/SpecialCaseList.h"
#include "llvm/Support/VirtualFileSystem.h"
#include "llvm/TargetParser/Triple.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/ModuleUtils.h"

usingnamespacellvm;

#define DEBUG_TYPE …

const char SanCovTracePCIndirName[] = …;
const char SanCovTracePCName[] = …;
const char SanCovTraceCmp1[] = …;
const char SanCovTraceCmp2[] = …;
const char SanCovTraceCmp4[] = …;
const char SanCovTraceCmp8[] = …;
const char SanCovTraceConstCmp1[] = …;
const char SanCovTraceConstCmp2[] = …;
const char SanCovTraceConstCmp4[] = …;
const char SanCovTraceConstCmp8[] = …;
const char SanCovLoad1[] = …;
const char SanCovLoad2[] = …;
const char SanCovLoad4[] = …;
const char SanCovLoad8[] = …;
const char SanCovLoad16[] = …;
const char SanCovStore1[] = …;
const char SanCovStore2[] = …;
const char SanCovStore4[] = …;
const char SanCovStore8[] = …;
const char SanCovStore16[] = …;
const char SanCovTraceDiv4[] = …;
const char SanCovTraceDiv8[] = …;
const char SanCovTraceGep[] = …;
const char SanCovTraceSwitchName[] = …;
const char SanCovModuleCtorTracePcGuardName[] = …;
const char SanCovModuleCtor8bitCountersName[] = …;
const char SanCovModuleCtorBoolFlagName[] = …;
static const uint64_t SanCtorAndDtorPriority = …;

const char SanCovTracePCGuardName[] = …;
const char SanCovTracePCGuardInitName[] = …;
const char SanCov8bitCountersInitName[] = …;
const char SanCovBoolFlagInitName[] = …;
const char SanCovPCsInitName[] = …;
const char SanCovCFsInitName[] = …;

const char SanCovGuardsSectionName[] = …;
const char SanCovCountersSectionName[] = …;
const char SanCovBoolFlagSectionName[] = …;
const char SanCovPCsSectionName[] = …;
const char SanCovCFsSectionName[] = …;

const char SanCovLowestStackName[] = …;

static cl::opt<int> ClCoverageLevel(
    "sanitizer-coverage-level",
    cl::desc("Sanitizer Coverage. 0: none, 1: entry block, 2: all blocks, "
             "3: all blocks and critical edges"),
    cl::Hidden);

static cl::opt<bool> ClTracePC("sanitizer-coverage-trace-pc",
                               cl::desc("Experimental pc tracing"), cl::Hidden);

static cl::opt<bool> ClTracePCGuard("sanitizer-coverage-trace-pc-guard",
                                    cl::desc("pc tracing with a guard"),
                                    cl::Hidden);

// If true, we create a global variable that contains PCs of all instrumented
// BBs, put this global into a named section, and pass this section's bounds
// to __sanitizer_cov_pcs_init.
// This way the coverage instrumentation does not need to acquire the PCs
// at run-time. Works with trace-pc-guard, inline-8bit-counters, and
// inline-bool-flag.
static cl::opt<bool> ClCreatePCTable("sanitizer-coverage-pc-table",
                                     cl::desc("create a static PC table"),
                                     cl::Hidden);

static cl::opt<bool>
    ClInline8bitCounters("sanitizer-coverage-inline-8bit-counters",
                         cl::desc("increments 8-bit counter for every edge"),
                         cl::Hidden);

static cl::opt<bool>
    ClInlineBoolFlag("sanitizer-coverage-inline-bool-flag",
                     cl::desc("sets a boolean flag for every edge"),
                     cl::Hidden);

static cl::opt<bool>
    ClCMPTracing("sanitizer-coverage-trace-compares",
                 cl::desc("Tracing of CMP and similar instructions"),
                 cl::Hidden);

static cl::opt<bool> ClDIVTracing("sanitizer-coverage-trace-divs",
                                  cl::desc("Tracing of DIV instructions"),
                                  cl::Hidden);

static cl::opt<bool> ClLoadTracing("sanitizer-coverage-trace-loads",
                                   cl::desc("Tracing of load instructions"),
                                   cl::Hidden);

static cl::opt<bool> ClStoreTracing("sanitizer-coverage-trace-stores",
                                    cl::desc("Tracing of store instructions"),
                                    cl::Hidden);

static cl::opt<bool> ClGEPTracing("sanitizer-coverage-trace-geps",
                                  cl::desc("Tracing of GEP instructions"),
                                  cl::Hidden);

static cl::opt<bool>
    ClPruneBlocks("sanitizer-coverage-prune-blocks",
                  cl::desc("Reduce the number of instrumented blocks"),
                  cl::Hidden, cl::init(true));

static cl::opt<bool> ClStackDepth("sanitizer-coverage-stack-depth",
                                  cl::desc("max stack depth tracing"),
                                  cl::Hidden);

static cl::opt<bool>
    ClCollectCF("sanitizer-coverage-control-flow",
                cl::desc("collect control flow for each function"), cl::Hidden);

namespace {

SanitizerCoverageOptions getOptions(int LegacyCoverageLevel) { … }

SanitizerCoverageOptions OverrideFromCL(SanitizerCoverageOptions Options) { … }

class ModuleSanitizerCoverage { … };
} // namespace

PreservedAnalyses SanitizerCoveragePass::run(Module &M,
                                             ModuleAnalysisManager &MAM) { … }

std::pair<Value *, Value *>
ModuleSanitizerCoverage::CreateSecStartEnd(Module &M, const char *Section,
                                           Type *Ty) { … }

Function *ModuleSanitizerCoverage::CreateInitCallsForSections(
    Module &M, const char *CtorName, const char *InitFunctionName, Type *Ty,
    const char *Section) { … }

bool ModuleSanitizerCoverage::instrumentModule() { … }

// True if block has successors and it dominates all of them.
static bool isFullDominator(const BasicBlock *BB, const DominatorTree &DT) { … }

// True if block has predecessors and it postdominates all of them.
static bool isFullPostDominator(const BasicBlock *BB,
                                const PostDominatorTree &PDT) { … }

static bool shouldInstrumentBlock(const Function &F, const BasicBlock *BB,
                                  const DominatorTree &DT,
                                  const PostDominatorTree &PDT,
                                  const SanitizerCoverageOptions &Options) { … }

// Returns true iff From->To is a backedge.
// A twist here is that we treat From->To as a backedge if
//   * To dominates From or
//   * To->UniqueSuccessor dominates From
static bool IsBackEdge(BasicBlock *From, BasicBlock *To,
                       const DominatorTree &DT) { … }

// Prunes uninteresting Cmp instrumentation:
//   * CMP instructions that feed into loop backedge branch.
//
// Note that Cmp pruning is controlled by the same flag as the
// BB pruning.
static bool IsInterestingCmp(ICmpInst *CMP, const DominatorTree &DT,
                             const SanitizerCoverageOptions &Options) { … }

void ModuleSanitizerCoverage::instrumentFunction(Function &F) { … }

GlobalVariable *ModuleSanitizerCoverage::CreateFunctionLocalArrayInSection(
    size_t NumElements, Function &F, Type *Ty, const char *Section) { … }

GlobalVariable *
ModuleSanitizerCoverage::CreatePCArray(Function &F,
                                       ArrayRef<BasicBlock *> AllBlocks) { … }

void ModuleSanitizerCoverage::CreateFunctionLocalArrays(
    Function &F, ArrayRef<BasicBlock *> AllBlocks) { … }

bool ModuleSanitizerCoverage::InjectCoverage(Function &F,
                                             ArrayRef<BasicBlock *> AllBlocks,
                                             bool IsLeafFunc) { … }

// On every indirect call we call a run-time function
// __sanitizer_cov_indir_call* with two parameters:
//   - callee address,
//   - global cache array that contains CacheSize pointers (zero-initialized).
//     The cache is used to speed up recording the caller-callee pairs.
// The address of the caller is passed implicitly via caller PC.
// CacheSize is encoded in the name of the run-time function.
void ModuleSanitizerCoverage::InjectCoverageForIndirectCalls(
    Function &F, ArrayRef<Instruction *> IndirCalls) { … }

// For every switch statement we insert a call:
// __sanitizer_cov_trace_switch(CondValue,
//      {NumCases, ValueSizeInBits, Case0Value, Case1Value, Case2Value, ... })

void ModuleSanitizerCoverage::InjectTraceForSwitch(
    Function &, ArrayRef<Instruction *> SwitchTraceTargets) { … }

void ModuleSanitizerCoverage::InjectTraceForDiv(
    Function &, ArrayRef<BinaryOperator *> DivTraceTargets) { … }

void ModuleSanitizerCoverage::InjectTraceForGep(
    Function &, ArrayRef<GetElementPtrInst *> GepTraceTargets) { … }

void ModuleSanitizerCoverage::InjectTraceForLoadsAndStores(
    Function &, ArrayRef<LoadInst *> Loads, ArrayRef<StoreInst *> Stores) { … }

void ModuleSanitizerCoverage::InjectTraceForCmp(
    Function &, ArrayRef<Instruction *> CmpTraceTargets) { … }

void ModuleSanitizerCoverage::InjectCoverageAtBlock(Function &F, BasicBlock &BB,
                                                    size_t Idx,
                                                    bool IsLeafFunc) { … }

std::string
ModuleSanitizerCoverage::getSectionName(const std::string &Section) const { … }

std::string
ModuleSanitizerCoverage::getSectionStart(const std::string &Section) const { … }

std::string
ModuleSanitizerCoverage::getSectionEnd(const std::string &Section) const { … }

void ModuleSanitizerCoverage::createFunctionControlFlow(Function &F) { … }
llvm/llvm/lib/Transforms/Instrumentation/SanitizerCoverage.cpp
