1 //===- Transforms/Instrumentation.h - Instrumentation passes ----*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines constructor functions for instrumentation passes.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_TRANSFORMS_INSTRUMENTATION_H
15 #define LLVM_TRANSFORMS_INSTRUMENTATION_H
16 
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/IR/BasicBlock.h"
19 #include <vector>
20 
21 #if defined(__GNUC__) && defined(__linux__) && !defined(ANDROID)
getDFSanArgTLSPtrForJIT()22 inline void *getDFSanArgTLSPtrForJIT() {
23   extern __thread __attribute__((tls_model("initial-exec")))
24     void *__dfsan_arg_tls;
25   return (void *)&__dfsan_arg_tls;
26 }
27 
getDFSanRetValTLSPtrForJIT()28 inline void *getDFSanRetValTLSPtrForJIT() {
29   extern __thread __attribute__((tls_model("initial-exec")))
30     void *__dfsan_retval_tls;
31   return (void *)&__dfsan_retval_tls;
32 }
33 #endif
34 
35 namespace llvm {
36 
37 class TargetMachine;
38 
39 /// Instrumentation passes often insert conditional checks into entry blocks.
40 /// Call this function before splitting the entry block to move instructions
41 /// that must remain in the entry block up before the split point. Static
42 /// allocas and llvm.localescape calls, for example, must remain in the entry
43 /// block.
44 BasicBlock::iterator PrepareToSplitEntryBlock(BasicBlock &BB,
45                                               BasicBlock::iterator IP);
46 
47 class ModulePass;
48 class FunctionPass;
49 
50 // Insert GCOV profiling instrumentation
51 struct GCOVOptions {
52   static GCOVOptions getDefault();
53 
54   // Specify whether to emit .gcno files.
55   bool EmitNotes;
56 
57   // Specify whether to modify the program to emit .gcda files when run.
58   bool EmitData;
59 
60   // A four-byte version string. The meaning of a version string is described in
61   // gcc's gcov-io.h
62   char Version[4];
63 
64   // Emit a "cfg checksum" that follows the "line number checksum" of a
65   // function. This affects both .gcno and .gcda files.
66   bool UseCfgChecksum;
67 
68   // Add the 'noredzone' attribute to added runtime library calls.
69   bool NoRedZone;
70 
71   // Emit the name of the function in the .gcda files. This is redundant, as
72   // the function identifier can be used to find the name from the .gcno file.
73   bool FunctionNamesInData;
74 
75   // Emit the exit block immediately after the start block, rather than after
76   // all of the function body's blocks.
77   bool ExitBlockBeforeBody;
78 };
79 ModulePass *createGCOVProfilerPass(const GCOVOptions &Options =
80                                    GCOVOptions::getDefault());
81 
82 // PGO Instrumention
83 ModulePass *createPGOInstrumentationGenPass();
84 ModulePass *
85 createPGOInstrumentationUsePass(StringRef Filename = StringRef(""));
86 
87 /// Options for the frontend instrumentation based profiling pass.
88 struct InstrProfOptions {
InstrProfOptionsInstrProfOptions89   InstrProfOptions() : NoRedZone(false) {}
90 
91   // Add the 'noredzone' attribute to added runtime library calls.
92   bool NoRedZone;
93 
94   // Name of the profile file to use as output
95   std::string InstrProfileOutput;
96 };
97 
98 /// Insert frontend instrumentation based profiling.
99 ModulePass *createInstrProfilingPass(
100     const InstrProfOptions &Options = InstrProfOptions());
101 
102 // Insert AddressSanitizer (address sanity checking) instrumentation
103 FunctionPass *createAddressSanitizerFunctionPass(bool CompileKernel = false,
104                                                  bool Recover = false);
105 ModulePass *createAddressSanitizerModulePass(bool CompileKernel = false,
106                                              bool Recover = false);
107 
108 // Insert MemorySanitizer instrumentation (detection of uninitialized reads)
109 FunctionPass *createMemorySanitizerPass(int TrackOrigins = 0);
110 
111 // Insert ThreadSanitizer (race detection) instrumentation
112 FunctionPass *createThreadSanitizerPass();
113 
114 // Insert DataFlowSanitizer (dynamic data flow analysis) instrumentation
115 ModulePass *createDataFlowSanitizerPass(
116     const std::vector<std::string> &ABIListFiles = std::vector<std::string>(),
117     void *(*getArgTLS)() = nullptr, void *(*getRetValTLS)() = nullptr);
118 
119 // Options for sanitizer coverage instrumentation.
120 struct SanitizerCoverageOptions {
SanitizerCoverageOptionsSanitizerCoverageOptions121   SanitizerCoverageOptions()
122       : CoverageType(SCK_None), IndirectCalls(false), TraceBB(false),
123         TraceCmp(false), Use8bitCounters(false) {}
124 
125   enum Type {
126     SCK_None = 0,
127     SCK_Function,
128     SCK_BB,
129     SCK_Edge
130   } CoverageType;
131   bool IndirectCalls;
132   bool TraceBB;
133   bool TraceCmp;
134   bool Use8bitCounters;
135 };
136 
137 // Insert SanitizerCoverage instrumentation.
138 ModulePass *createSanitizerCoverageModulePass(
139     const SanitizerCoverageOptions &Options = SanitizerCoverageOptions());
140 
141 #if defined(__GNUC__) && defined(__linux__) && !defined(ANDROID)
142 inline ModulePass *createDataFlowSanitizerPassForJIT(
143     const std::vector<std::string> &ABIListFiles = std::vector<std::string>()) {
144   return createDataFlowSanitizerPass(ABIListFiles, getDFSanArgTLSPtrForJIT,
145                                      getDFSanRetValTLSPtrForJIT);
146 }
147 #endif
148 
149 // BoundsChecking - This pass instruments the code to perform run-time bounds
150 // checking on loads, stores, and other memory intrinsics.
151 FunctionPass *createBoundsCheckingPass();
152 
153 /// \brief This pass splits the stack into a safe stack and an unsafe stack to
154 /// protect against stack-based overflow vulnerabilities.
155 FunctionPass *createSafeStackPass(const TargetMachine *TM = nullptr);
156 
157 /// \brief Calculate what to divide by to scale counts.
158 ///
159 /// Given the maximum count, calculate a divisor that will scale all the
160 /// weights to strictly less than UINT32_MAX.
calculateCountScale(uint64_t MaxCount)161 static inline uint64_t calculateCountScale(uint64_t MaxCount) {
162   return MaxCount < UINT32_MAX ? 1 : MaxCount / UINT32_MAX + 1;
163 }
164 
165 /// \brief Scale an individual branch count.
166 ///
167 /// Scale a 64-bit weight down to 32-bits using \c Scale.
168 ///
scaleBranchCount(uint64_t Count,uint64_t Scale)169 static inline uint32_t scaleBranchCount(uint64_t Count, uint64_t Scale) {
170   uint64_t Scaled = Count / Scale;
171   assert(Scaled <= UINT32_MAX && "overflow 32-bits");
172   return Scaled;
173 }
174 
175 } // End llvm namespace
176 
177 #endif
178