/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Bug Summary

File:	llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
Warning:	line 678, column 19 Called C++ object pointer is null
Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name AddressSanitizer.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Transforms/Instrumentation -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Transforms/Instrumentation -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Transforms/Instrumentation -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/include -D NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/build-llvm/lib/Transforms/Instrumentation -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-09-04-040900-46481-1 -x c++ /build/llvm-toolchain-snapshot-14~++20210903100615+fd66b44ec19e/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
1//===- AddressSanitizer.cpp - memory error detector -----------------------===//
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// This file is a part of AddressSanitizer, an address sanity checker.
10// Details of the algorithm:
11//  https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm
12//
13// FIXME: This sanitizer does not yet handle scalable vectors
14//
15//===----------------------------------------------------------------------===//

17#include "llvm/Transforms/Instrumentation/AddressSanitizer.h"
18#include "llvm/ADT/ArrayRef.h"
19#include "llvm/ADT/DenseMap.h"
20#include "llvm/ADT/DepthFirstIterator.h"
21#include "llvm/ADT/SmallPtrSet.h"
22#include "llvm/ADT/SmallVector.h"
23#include "llvm/ADT/Statistic.h"
24#include "llvm/ADT/StringExtras.h"
25#include "llvm/ADT/StringRef.h"
26#include "llvm/ADT/Triple.h"
27#include "llvm/ADT/Twine.h"
28#include "llvm/Analysis/MemoryBuiltins.h"
29#include "llvm/Analysis/TargetLibraryInfo.h"
30#include "llvm/Analysis/ValueTracking.h"
31#include "llvm/BinaryFormat/MachO.h"
32#include "llvm/IR/Argument.h"
33#include "llvm/IR/Attributes.h"
34#include "llvm/IR/BasicBlock.h"
35#include "llvm/IR/Comdat.h"
36#include "llvm/IR/Constant.h"
37#include "llvm/IR/Constants.h"
38#include "llvm/IR/DIBuilder.h"
39#include "llvm/IR/DataLayout.h"
40#include "llvm/IR/DebugInfoMetadata.h"
41#include "llvm/IR/DebugLoc.h"
42#include "llvm/IR/DerivedTypes.h"
43#include "llvm/IR/Dominators.h"
44#include "llvm/IR/Function.h"
45#include "llvm/IR/GlobalAlias.h"
46#include "llvm/IR/GlobalValue.h"
47#include "llvm/IR/GlobalVariable.h"
48#include "llvm/IR/IRBuilder.h"
49#include "llvm/IR/InlineAsm.h"
50#include "llvm/IR/InstVisitor.h"
51#include "llvm/IR/InstrTypes.h"
52#include "llvm/IR/Instruction.h"
53#include "llvm/IR/Instructions.h"
54#include "llvm/IR/IntrinsicInst.h"
55#include "llvm/IR/Intrinsics.h"
56#include "llvm/IR/LLVMContext.h"
57#include "llvm/IR/MDBuilder.h"
58#include "llvm/IR/Metadata.h"
59#include "llvm/IR/Module.h"
60#include "llvm/IR/Type.h"
61#include "llvm/IR/Use.h"
62#include "llvm/IR/Value.h"
63#include "llvm/InitializePasses.h"
64#include "llvm/MC/MCSectionMachO.h"
65#include "llvm/Pass.h"
66#include "llvm/Support/Casting.h"
67#include "llvm/Support/CommandLine.h"
68#include "llvm/Support/Debug.h"
69#include "llvm/Support/ErrorHandling.h"
70#include "llvm/Support/MathExtras.h"
71#include "llvm/Support/ScopedPrinter.h"
72#include "llvm/Support/raw_ostream.h"
73#include "llvm/Transforms/Instrumentation.h"
74#include "llvm/Transforms/Instrumentation/AddressSanitizerCommon.h"
75#include "llvm/Transforms/Instrumentation/AddressSanitizerOptions.h"
76#include "llvm/Transforms/Utils/ASanStackFrameLayout.h"
77#include "llvm/Transforms/Utils/BasicBlockUtils.h"
78#include "llvm/Transforms/Utils/Local.h"
79#include "llvm/Transforms/Utils/ModuleUtils.h"
80#include "llvm/Transforms/Utils/PromoteMemToReg.h"
81#include <algorithm>
82#include <cassert>
83#include <cstddef>
84#include <cstdint>
85#include <iomanip>
86#include <limits>
87#include <memory>
88#include <sstream>
89#include <string>
90#include <tuple>

92using namespace llvm;

94#define DEBUG_TYPE"asan" "asan"

96static const uint64_t kDefaultShadowScale = 3;
97static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
98static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
99static const uint64_t kDynamicShadowSentinel =
  std::numeric_limits<uint64_t>::max();
101static const uint64_t kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF;  // < 2G.
102static const uint64_t kSmallX86_64ShadowOffsetAlignMask = ~0xFFFULL;
103static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
104static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 44;
105static const uint64_t kSystemZ_ShadowOffset64 = 1ULL << 52;
106static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
107static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
108static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
109static const uint64_t kRISCV64_ShadowOffset64 = 0xd55550000;
110static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
111static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
112static const uint64_t kFreeBSDKasan_ShadowOffset64 = 0xdffff7c000000000;
113static const uint64_t kNetBSD_ShadowOffset32 = 1ULL << 30;
114static const uint64_t kNetBSD_ShadowOffset64 = 1ULL << 46;
115static const uint64_t kNetBSDKasan_ShadowOffset64 = 0xdfff900000000000;
116static const uint64_t kPS4CPU_ShadowOffset64 = 1ULL << 40;
117static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;
118static const uint64_t kEmscriptenShadowOffset = 0;

120// The shadow memory space is dynamically allocated.
121static const uint64_t kWindowsShadowOffset64 = kDynamicShadowSentinel;

123static const size_t kMinStackMallocSize = 1 << 6;   // 64B
124static const size_t kMaxStackMallocSize = 1 << 16;  // 64K
125static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
126static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;

128const char kAsanModuleCtorName[] = "asan.module_ctor";
129const char kAsanModuleDtorName[] = "asan.module_dtor";
130static const uint64_t kAsanCtorAndDtorPriority = 1;
131// On Emscripten, the system needs more than one priorities for constructors.
132static const uint64_t kAsanEmscriptenCtorAndDtorPriority = 50;
133const char kAsanReportErrorTemplate[] = "__asan_report_";
134const char kAsanRegisterGlobalsName[] = "__asan_register_globals";
135const char kAsanUnregisterGlobalsName[] = "__asan_unregister_globals";
136const char kAsanRegisterImageGlobalsName[] = "__asan_register_image_globals";
137const char kAsanUnregisterImageGlobalsName[] =
  "__asan_unregister_image_globals";
139const char kAsanRegisterElfGlobalsName[] = "__asan_register_elf_globals";
140const char kAsanUnregisterElfGlobalsName[] = "__asan_unregister_elf_globals";
141const char kAsanPoisonGlobalsName[] = "__asan_before_dynamic_init";
142const char kAsanUnpoisonGlobalsName[] = "__asan_after_dynamic_init";
143const char kAsanInitName[] = "__asan_init";
144const char kAsanVersionCheckNamePrefix[] = "__asan_version_mismatch_check_v";
145const char kAsanPtrCmp[] = "__sanitizer_ptr_cmp";
146const char kAsanPtrSub[] = "__sanitizer_ptr_sub";
147const char kAsanHandleNoReturnName[] = "__asan_handle_no_return";
148static const int kMaxAsanStackMallocSizeClass = 10;
149const char kAsanStackMallocNameTemplate[] = "__asan_stack_malloc_";
150const char kAsanStackMallocAlwaysNameTemplate[] =
  "__asan_stack_malloc_always_";
152const char kAsanStackFreeNameTemplate[] = "__asan_stack_free_";
153const char kAsanGenPrefix[] = "___asan_gen_";
154const char kODRGenPrefix[] = "__odr_asan_gen_";
155const char kSanCovGenPrefix[] = "__sancov_gen_";
156const char kAsanSetShadowPrefix[] = "__asan_set_shadow_";
157const char kAsanPoisonStackMemoryName[] = "__asan_poison_stack_memory";
158const char kAsanUnpoisonStackMemoryName[] = "__asan_unpoison_stack_memory";

160// ASan version script has __asan_* wildcard. Triple underscore prevents a
161// linker (gold) warning about attempting to export a local symbol.
162const char kAsanGlobalsRegisteredFlagName[] = "___asan_globals_registered";

164const char kAsanOptionDetectUseAfterReturn[] =
  "__asan_option_detect_stack_use_after_return";

167const char kAsanShadowMemoryDynamicAddress[] =
  "__asan_shadow_memory_dynamic_address";

170const char kAsanAllocaPoison[] = "__asan_alloca_poison";
171const char kAsanAllocasUnpoison[] = "__asan_allocas_unpoison";

173const char kAMDGPUAddressSharedName[] = "llvm.amdgcn.is.shared";
174const char kAMDGPUAddressPrivateName[] = "llvm.amdgcn.is.private";

176// Accesses sizes are powers of two: 1, 2, 4, 8, 16.
177static const size_t kNumberOfAccessSizes = 5;

179static const unsigned kAllocaRzSize = 32;

181// ASanAccessInfo implementation constants.
182constexpr size_t kCompileKernelShift = 0;
183constexpr size_t kCompileKernelMask = 0x1;
184constexpr size_t kAccessSizeIndexShift = 1;
185constexpr size_t kAccessSizeIndexMask = 0xf;
186constexpr size_t kIsWriteShift = 5;
187constexpr size_t kIsWriteMask = 0x1;

189// Command-line flags.

191static cl::opt<bool> ClEnableKasan(
  "asan-kernel", cl::desc("Enable KernelAddressSanitizer instrumentation"),
  cl::Hidden, cl::init(false));

195static cl::opt<bool> ClRecover(
  "asan-recover",
  cl::desc("Enable recovery mode (continue-after-error)."),
  cl::Hidden, cl::init(false));

200static cl::opt<bool> ClInsertVersionCheck(
  "asan-guard-against-version-mismatch",
  cl::desc("Guard against compiler/runtime version mismatch."),
  cl::Hidden, cl::init(true));

205// This flag may need to be replaced with -f[no-]asan-reads.
206static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
                                     cl::desc("instrument read instructions"),
                                     cl::Hidden, cl::init(true));

210static cl::opt<bool> ClInstrumentWrites(
  "asan-instrument-writes", cl::desc("instrument write instructions"),
  cl::Hidden, cl::init(true));

214static cl::opt<bool> ClInstrumentAtomics(
  "asan-instrument-atomics",
  cl::desc("instrument atomic instructions (rmw, cmpxchg)"), cl::Hidden,
  cl::init(true));

219static cl::opt<bool>
  ClInstrumentByval("asan-instrument-byval",
                    cl::desc("instrument byval call arguments"), cl::Hidden,
                    cl::init(true));

224static cl::opt<bool> ClAlwaysSlowPath(
  "asan-always-slow-path",
  cl::desc("use instrumentation with slow path for all accesses"), cl::Hidden,
  cl::init(false));

229static cl::opt<bool> ClForceDynamicShadow(
  "asan-force-dynamic-shadow",
  cl::desc("Load shadow address into a local variable for each function"),
  cl::Hidden, cl::init(false));

234static cl::opt<bool>
  ClWithIfunc("asan-with-ifunc",
              cl::desc("Access dynamic shadow through an ifunc global on "
                       "platforms that support this"),
              cl::Hidden, cl::init(true));

240static cl::opt<bool> ClWithIfuncSuppressRemat(
  "asan-with-ifunc-suppress-remat",
  cl::desc("Suppress rematerialization of dynamic shadow address by passing "
           "it through inline asm in prologue."),
  cl::Hidden, cl::init(true));

246// This flag limits the number of instructions to be instrumented
247// in any given BB. Normally, this should be set to unlimited (INT_MAX),
248// but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
249// set it to 10000.
250static cl::opt<int> ClMaxInsnsToInstrumentPerBB(
  "asan-max-ins-per-bb", cl::init(10000),
  cl::desc("maximal number of instructions to instrument in any given BB"),
  cl::Hidden);

255// This flag may need to be replaced with -f[no]asan-stack.
256static cl::opt<bool> ClStack("asan-stack", cl::desc("Handle stack memory"),
                           cl::Hidden, cl::init(true));
258static cl::opt<uint32_t> ClMaxInlinePoisoningSize(
  "asan-max-inline-poisoning-size",
  cl::desc(
      "Inline shadow poisoning for blocks up to the given size in bytes."),
  cl::Hidden, cl::init(64));

264static cl::opt<AsanDetectStackUseAfterReturnMode> ClUseAfterReturn(
  "asan-use-after-return",
  cl::desc("Sets the mode of detection for stack-use-after-return."),
  cl::values(
      clEnumValN(AsanDetectStackUseAfterReturnMode::Never, "never",llvm::cl::OptionEnumValue { "never", int(AsanDetectStackUseAfterReturnMode
::Never), "Never detect stack use after return." }
                 "Never detect stack use after return.")llvm::cl::OptionEnumValue { "never", int(AsanDetectStackUseAfterReturnMode
::Never), "Never detect stack use after return." },
      clEnumValN(llvm::cl::OptionEnumValue { "runtime", int(AsanDetectStackUseAfterReturnMode
::Runtime), "Detect stack use after return if " "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set."
 }
          AsanDetectStackUseAfterReturnMode::Runtime, "runtime",llvm::cl::OptionEnumValue { "runtime", int(AsanDetectStackUseAfterReturnMode
::Runtime), "Detect stack use after return if " "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set."
 }
          "Detect stack use after return if "llvm::cl::OptionEnumValue { "runtime", int(AsanDetectStackUseAfterReturnMode
::Runtime), "Detect stack use after return if " "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set."
 }
          "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set.")llvm::cl::OptionEnumValue { "runtime", int(AsanDetectStackUseAfterReturnMode
::Runtime), "Detect stack use after return if " "binary flag 'ASAN_OPTIONS=detect_stack_use_after_return' is set."
 },
      clEnumValN(AsanDetectStackUseAfterReturnMode::Always, "always",llvm::cl::OptionEnumValue { "always", int(AsanDetectStackUseAfterReturnMode
::Always), "Always detect stack use after return." }
                 "Always detect stack use after return.")llvm::cl::OptionEnumValue { "always", int(AsanDetectStackUseAfterReturnMode
::Always), "Always detect stack use after return." }),
  cl::Hidden, cl::init(AsanDetectStackUseAfterReturnMode::Runtime));

278static cl::opt<bool> ClRedzoneByvalArgs("asan-redzone-byval-args",
                                      cl::desc("Create redzones for byval "
                                               "arguments (extra copy "
                                               "required)"), cl::Hidden,
                                      cl::init(true));

284static cl::opt<bool> ClUseAfterScope("asan-use-after-scope",
                                   cl::desc("Check stack-use-after-scope"),
                                   cl::Hidden, cl::init(false));

288// This flag may need to be replaced with -f[no]asan-globals.
289static cl::opt<bool> ClGlobals("asan-globals",
                             cl::desc("Handle global objects"), cl::Hidden,
                             cl::init(true));

293static cl::opt<bool> ClInitializers("asan-initialization-order",
                                  cl::desc("Handle C++ initializer order"),
                                  cl::Hidden, cl::init(true));

297static cl::opt<bool> ClInvalidPointerPairs(
  "asan-detect-invalid-pointer-pair",
  cl::desc("Instrument <, <=, >, >=, - with pointer operands"), cl::Hidden,
  cl::init(false));

302static cl::opt<bool> ClInvalidPointerCmp(
  "asan-detect-invalid-pointer-cmp",
  cl::desc("Instrument <, <=, >, >= with pointer operands"), cl::Hidden,
  cl::init(false));

307static cl::opt<bool> ClInvalidPointerSub(
  "asan-detect-invalid-pointer-sub",
  cl::desc("Instrument - operations with pointer operands"), cl::Hidden,
  cl::init(false));

312static cl::opt<unsigned> ClRealignStack(
  "asan-realign-stack",
  cl::desc("Realign stack to the value of this flag (power of two)"),
  cl::Hidden, cl::init(32));

317static cl::opt<int> ClInstrumentationWithCallsThreshold(
  "asan-instrumentation-with-call-threshold",
  cl::desc(
      "If the function being instrumented contains more than "
      "this number of memory accesses, use callbacks instead of "
      "inline checks (-1 means never use callbacks)."),
  cl::Hidden, cl::init(7000));

325static cl::opt<std::string> ClMemoryAccessCallbackPrefix(
  "asan-memory-access-callback-prefix",
  cl::desc("Prefix for memory access callbacks"), cl::Hidden,
  cl::init("__asan_"));

330static cl::opt<bool>
  ClInstrumentDynamicAllocas("asan-instrument-dynamic-allocas",
                             cl::desc("instrument dynamic allocas"),
                             cl::Hidden, cl::init(true));

335static cl::opt<bool> ClSkipPromotableAllocas(
  "asan-skip-promotable-allocas",
  cl::desc("Do not instrument promotable allocas"), cl::Hidden,
  cl::init(true));

340// These flags allow to change the shadow mapping.
341// The shadow mapping looks like
342//    Shadow = (Mem >> scale) + offset

344static cl::opt<int> ClMappingScale("asan-mapping-scale",
                                 cl::desc("scale of asan shadow mapping"),
                                 cl::Hidden, cl::init(0));

348static cl::opt<uint64_t>
  ClMappingOffset("asan-mapping-offset",
                  cl::desc("offset of asan shadow mapping [EXPERIMENTAL]"),
                  cl::Hidden, cl::init(0));

353// Optimization flags. Not user visible, used mostly for testing
354// and benchmarking the tool.

356static cl::opt<bool> ClOpt("asan-opt", cl::desc("Optimize instrumentation"),
                         cl::Hidden, cl::init(true));

359static cl::opt<bool> ClOptimizeCallbacks("asan-optimize-callbacks",
                                       cl::desc("Optimize callbacks"),
                                       cl::Hidden, cl::init(false));

363static cl::opt<bool> ClOptSameTemp(
  "asan-opt-same-temp", cl::desc("Instrument the same temp just once"),
  cl::Hidden, cl::init(true));

367static cl::opt<bool> ClOptGlobals("asan-opt-globals",
                                cl::desc("Don't instrument scalar globals"),
                                cl::Hidden, cl::init(true));

371static cl::opt<bool> ClOptStack(
  "asan-opt-stack", cl::desc("Don't instrument scalar stack variables"),
  cl::Hidden, cl::init(false));

375static cl::opt<bool> ClDynamicAllocaStack(
  "asan-stack-dynamic-alloca",
  cl::desc("Use dynamic alloca to represent stack variables"), cl::Hidden,
  cl::init(true));

380static cl::opt<uint32_t> ClForceExperiment(
  "asan-force-experiment",
  cl::desc("Force optimization experiment (for testing)"), cl::Hidden,
  cl::init(0));

385static cl::opt<bool>
  ClUsePrivateAlias("asan-use-private-alias",
                    cl::desc("Use private aliases for global variables"),
                    cl::Hidden, cl::init(false));

390static cl::opt<bool>
  ClUseOdrIndicator("asan-use-odr-indicator",
                    cl::desc("Use odr indicators to improve ODR reporting"),
                    cl::Hidden, cl::init(false));

395static cl::opt<bool>
  ClUseGlobalsGC("asan-globals-live-support",
                 cl::desc("Use linker features to support dead "
                          "code stripping of globals"),
                 cl::Hidden, cl::init(true));

401// This is on by default even though there is a bug in gold:
402// https://sourceware.org/bugzilla/show_bug.cgi?id=19002
403static cl::opt<bool>
  ClWithComdat("asan-with-comdat",
               cl::desc("Place ASan constructors in comdat sections"),
               cl::Hidden, cl::init(true));

408static cl::opt<AsanDtorKind> ClOverrideDestructorKind(
  "asan-destructor-kind",
  cl::desc("Sets the ASan destructor kind. The default is to use the value "
           "provided to the pass constructor"),
  cl::values(clEnumValN(AsanDtorKind::None, "none", "No destructors")llvm::cl::OptionEnumValue { "none", int(AsanDtorKind::None), "No destructors"
 },
             clEnumValN(AsanDtorKind::Global, "global",llvm::cl::OptionEnumValue { "global", int(AsanDtorKind::Global
), "Use global destructors" }
                        "Use global destructors")llvm::cl::OptionEnumValue { "global", int(AsanDtorKind::Global
), "Use global destructors" }),
  cl::init(AsanDtorKind::Invalid), cl::Hidden);

417// Debug flags.

419static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
                          cl::init(0));

422static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
                               cl::Hidden, cl::init(0));

425static cl::opt<std::string> ClDebugFunc("asan-debug-func", cl::Hidden,
                                      cl::desc("Debug func"));

428static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
                             cl::Hidden, cl::init(-1));

431static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
                             cl::Hidden, cl::init(-1));

434STATISTIC(NumInstrumentedReads, "Number of instrumented reads")static llvm::Statistic NumInstrumentedReads = {"asan", "NumInstrumentedReads"
, "Number of instrumented reads"};
435STATISTIC(NumInstrumentedWrites, "Number of instrumented writes")static llvm::Statistic NumInstrumentedWrites = {"asan", "NumInstrumentedWrites"
, "Number of instrumented writes"};
436STATISTIC(NumOptimizedAccessesToGlobalVar,static llvm::Statistic NumOptimizedAccessesToGlobalVar = {"asan"
, "NumOptimizedAccessesToGlobalVar", "Number of optimized accesses to global vars"
}
        "Number of optimized accesses to global vars")static llvm::Statistic NumOptimizedAccessesToGlobalVar = {"asan"
, "NumOptimizedAccessesToGlobalVar", "Number of optimized accesses to global vars"
};
438STATISTIC(NumOptimizedAccessesToStackVar,static llvm::Statistic NumOptimizedAccessesToStackVar = {"asan"
, "NumOptimizedAccessesToStackVar", "Number of optimized accesses to stack vars"
}
        "Number of optimized accesses to stack vars")static llvm::Statistic NumOptimizedAccessesToStackVar = {"asan"
, "NumOptimizedAccessesToStackVar", "Number of optimized accesses to stack vars"
};

441namespace {

443/// This struct defines the shadow mapping using the rule:
444///   shadow = (mem >> Scale) ADD-or-OR Offset.
445/// If InGlobal is true, then
446///   extern char __asan_shadow[];
447///   shadow = (mem >> Scale) + &__asan_shadow
448struct ShadowMapping {
int Scale;
uint64_t Offset;
bool OrShadowOffset;
bool InGlobal;
453};

455} // end anonymous namespace

457static ShadowMapping getShadowMapping(const Triple &TargetTriple, int LongSize,
                                    bool IsKasan) {
bool IsAndroid = TargetTriple.isAndroid();
bool IsIOS = TargetTriple.isiOS() || TargetTriple.isWatchOS();
bool IsMacOS = TargetTriple.isMacOSX();
bool IsFreeBSD = TargetTriple.isOSFreeBSD();
bool IsNetBSD = TargetTriple.isOSNetBSD();
bool IsPS4CPU = TargetTriple.isPS4CPU();
bool IsLinux = TargetTriple.isOSLinux();
bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
               TargetTriple.getArch() == Triple::ppc64le;
bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
bool IsMIPS32 = TargetTriple.isMIPS32();
bool IsMIPS64 = TargetTriple.isMIPS64();
bool IsArmOrThumb = TargetTriple.isARM() || TargetTriple.isThumb();
bool IsAArch64 = TargetTriple.getArch() == Triple::aarch64;
bool IsRISCV64 = TargetTriple.getArch() == Triple::riscv64;
bool IsWindows = TargetTriple.isOSWindows();
bool IsFuchsia = TargetTriple.isOSFuchsia();
bool IsEmscripten = TargetTriple.isOSEmscripten();
bool IsAMDGPU = TargetTriple.isAMDGPU();

ShadowMapping Mapping;

Mapping.Scale = kDefaultShadowScale;
if (ClMappingScale.getNumOccurrences() > 0) {
  Mapping.Scale = ClMappingScale;
}

if (LongSize == 32) {
  if (IsAndroid)
    Mapping.Offset = kDynamicShadowSentinel;
  else if (IsMIPS32)
    Mapping.Offset = kMIPS32_ShadowOffset32;
  else if (IsFreeBSD)
    Mapping.Offset = kFreeBSD_ShadowOffset32;
  else if (IsNetBSD)
    Mapping.Offset = kNetBSD_ShadowOffset32;
  else if (IsIOS)
    Mapping.Offset = kDynamicShadowSentinel;
  else if (IsWindows)
    Mapping.Offset = kWindowsShadowOffset32;
  else if (IsEmscripten)
    Mapping.Offset = kEmscriptenShadowOffset;
  else
    Mapping.Offset = kDefaultShadowOffset32;
} else {  // LongSize == 64
  // Fuchsia is always PIE, which means that the beginning of the address
  // space is always available.
  if (IsFuchsia)
    Mapping.Offset = 0;
  else if (IsPPC64)
    Mapping.Offset = kPPC64_ShadowOffset64;
  else if (IsSystemZ)
    Mapping.Offset = kSystemZ_ShadowOffset64;
  else if (IsFreeBSD && !IsMIPS64) {
    if (IsKasan)
      Mapping.Offset = kFreeBSDKasan_ShadowOffset64;
    else
      Mapping.Offset = kFreeBSD_ShadowOffset64;
  } else if (IsNetBSD) {
    if (IsKasan)
      Mapping.Offset = kNetBSDKasan_ShadowOffset64;
    else
      Mapping.Offset = kNetBSD_ShadowOffset64;
  } else if (IsPS4CPU)
    Mapping.Offset = kPS4CPU_ShadowOffset64;
  else if (IsLinux && IsX86_64) {
    if (IsKasan)
      Mapping.Offset = kLinuxKasan_ShadowOffset64;
    else
      Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
                        (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
  } else if (IsWindows && IsX86_64) {
    Mapping.Offset = kWindowsShadowOffset64;
  } else if (IsMIPS64)
    Mapping.Offset = kMIPS64_ShadowOffset64;
  else if (IsIOS)
    Mapping.Offset = kDynamicShadowSentinel;
  else if (IsMacOS && IsAArch64)
    Mapping.Offset = kDynamicShadowSentinel;
  else if (IsAArch64)
    Mapping.Offset = kAArch64_ShadowOffset64;
  else if (IsRISCV64)
    Mapping.Offset = kRISCV64_ShadowOffset64;
  else if (IsAMDGPU)
    Mapping.Offset = (kSmallX86_64ShadowOffsetBase &
                      (kSmallX86_64ShadowOffsetAlignMask << Mapping.Scale));
  else
    Mapping.Offset = kDefaultShadowOffset64;
}

if (ClForceDynamicShadow) {
  Mapping.Offset = kDynamicShadowSentinel;
}

if (ClMappingOffset.getNumOccurrences() > 0) {
  Mapping.Offset = ClMappingOffset;
}

// OR-ing shadow offset if more efficient (at least on x86) if the offset
// is a power of two, but on ppc64 we have to use add since the shadow
// offset is not necessary 1/8-th of the address space.  On SystemZ,
// we could OR the constant in a single instruction, but it's more
// efficient to load it once and use indexed addressing.
Mapping.OrShadowOffset = !IsAArch64 && !IsPPC64 && !IsSystemZ && !IsPS4CPU &&
                         !IsRISCV64 &&
                         !(Mapping.Offset & (Mapping.Offset - 1)) &&
                         Mapping.Offset != kDynamicShadowSentinel;
bool IsAndroidWithIfuncSupport =
    IsAndroid && !TargetTriple.isAndroidVersionLT(21);
Mapping.InGlobal = ClWithIfunc && IsAndroidWithIfuncSupport && IsArmOrThumb;

return Mapping;
572}

574namespace llvm {
575void getAddressSanitizerParams(const Triple &TargetTriple, int LongSize,
                             bool IsKasan, uint64_t *ShadowBase,
                             int *MappingScale, bool *OrShadowOffset) {
auto Mapping = getShadowMapping(TargetTriple, LongSize, IsKasan);
*ShadowBase = Mapping.Offset;
*MappingScale = Mapping.Scale;
*OrShadowOffset = Mapping.OrShadowOffset;
582}

584ASanAccessInfo::ASanAccessInfo(int32_t Packed)
  : Packed(Packed),
    AccessSizeIndex((Packed >> kAccessSizeIndexShift) & kAccessSizeIndexMask),
    IsWrite((Packed >> kIsWriteShift) & kIsWriteMask),
    CompileKernel((Packed >> kCompileKernelShift) & kCompileKernelMask) {}

590ASanAccessInfo::ASanAccessInfo(bool IsWrite, bool CompileKernel,
                             uint8_t AccessSizeIndex)
  : Packed((IsWrite << kIsWriteShift) +
           (CompileKernel << kCompileKernelShift) +
           (AccessSizeIndex << kAccessSizeIndexShift)),
    AccessSizeIndex(AccessSizeIndex), IsWrite(IsWrite),
    CompileKernel(CompileKernel) {}

598} // namespace llvm

600static uint64_t getRedzoneSizeForScale(int MappingScale) {
// Redzone used for stack and globals is at least 32 bytes.
// For scales 6 and 7, the redzone has to be 64 and 128 bytes respectively.
return std::max(32U, 1U << MappingScale);
604}

606static uint64_t GetCtorAndDtorPriority(Triple &TargetTriple) {
if (TargetTriple.isOSEmscripten()) {
  return kAsanEmscriptenCtorAndDtorPriority;
} else {
  return kAsanCtorAndDtorPriority;
}
612}

614namespace {

616/// Module analysis for getting various metadata about the module.
617class ASanGlobalsMetadataWrapperPass : public ModulePass {
618public:
static char ID;

ASanGlobalsMetadataWrapperPass() : ModulePass(ID) {
  initializeASanGlobalsMetadataWrapperPassPass(
      *PassRegistry::getPassRegistry());
}

bool runOnModule(Module &M) override {
  GlobalsMD = GlobalsMetadata(M);
  return false;
}

StringRef getPassName() const override {
  return "ASanGlobalsMetadataWrapperPass";
}

void getAnalysisUsage(AnalysisUsage &AU) const override {
  AU.setPreservesAll();
}

GlobalsMetadata &getGlobalsMD() { return GlobalsMD; }

641private:
GlobalsMetadata GlobalsMD;
643};

645char ASanGlobalsMetadataWrapperPass::ID = 0;

647/// AddressSanitizer: instrument the code in module to find memory bugs.
648struct AddressSanitizer {
AddressSanitizer(Module &M, const GlobalsMetadata *GlobalsMD,
                 bool CompileKernel = false, bool Recover = false,
                 bool UseAfterScope = false,
                 AsanDetectStackUseAfterReturnMode UseAfterReturn =
                     AsanDetectStackUseAfterReturnMode::Runtime)
    : CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
                                                          : CompileKernel),
      Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
      UseAfterScope(UseAfterScope || ClUseAfterScope),
      UseAfterReturn(ClUseAfterReturn.getNumOccurrences() ? ClUseAfterReturn
                                                          : UseAfterReturn),
      GlobalsMD(*GlobalsMD) {
  C = &(M.getContext());
  LongSize = M.getDataLayout().getPointerSizeInBits();
  IntptrTy = Type::getIntNTy(*C, LongSize);
  Int8PtrTy = Type::getInt8PtrTy(*C);
  Int32Ty = Type::getInt32Ty(*C);
  TargetTriple = Triple(M.getTargetTriple());

  Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);

  assert(this->UseAfterReturn != AsanDetectStackUseAfterReturnMode::Invalid)(static_cast<void> (0));
}

uint64_t getAllocaSizeInBytes(const AllocaInst &AI) const {
  uint64_t ArraySize = 1;
  if (AI.isArrayAllocation()) {
18
←
Assuming the condition is true→
19
←
Taking true branch→
    const ConstantInt *CI = dyn_cast<ConstantInt>(AI.getArraySize());
20
←
Assuming the object is not a 'ConstantInt'→
21
←
'CI' initialized to a null pointer value→
    assert(CI && "non-constant array size")(static_cast<void> (0));
    ArraySize = CI->getZExtValue();
22
←
Called C++ object pointer is null
  }
  Type *Ty = AI.getAllocatedType();
  uint64_t SizeInBytes =
      AI.getModule()->getDataLayout().getTypeAllocSize(Ty);
  return SizeInBytes * ArraySize;
}

/// Check if we want (and can) handle this alloca.
bool isInterestingAlloca(const AllocaInst &AI);

bool ignoreAccess(Value *Ptr);
void getInterestingMemoryOperands(
    Instruction *I, SmallVectorImpl<InterestingMemoryOperand> &Interesting);

void instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
                   InterestingMemoryOperand &O, bool UseCalls,
                   const DataLayout &DL);
void instrumentPointerComparisonOrSubtraction(Instruction *I);
void instrumentAddress(Instruction *OrigIns, Instruction *InsertBefore,
                       Value *Addr, uint32_t TypeSize, bool IsWrite,
                       Value *SizeArgument, bool UseCalls, uint32_t Exp);
Instruction *instrumentAMDGPUAddress(Instruction *OrigIns,
                                     Instruction *InsertBefore, Value *Addr,
                                     uint32_t TypeSize, bool IsWrite,
                                     Value *SizeArgument);
void instrumentUnusualSizeOrAlignment(Instruction *I,
                                      Instruction *InsertBefore, Value *Addr,
                                      uint32_t TypeSize, bool IsWrite,
                                      Value *SizeArgument, bool UseCalls,
                                      uint32_t Exp);
Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
                         Value *ShadowValue, uint32_t TypeSize);
Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
                               bool IsWrite, size_t AccessSizeIndex,
                               Value *SizeArgument, uint32_t Exp);
void instrumentMemIntrinsic(MemIntrinsic *MI);
Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
bool suppressInstrumentationSiteForDebug(int &Instrumented);
bool instrumentFunction(Function &F, const TargetLibraryInfo *TLI);
bool maybeInsertAsanInitAtFunctionEntry(Function &F);
bool maybeInsertDynamicShadowAtFunctionEntry(Function &F);
void markEscapedLocalAllocas(Function &F);

722private:
friend struct FunctionStackPoisoner;

void initializeCallbacks(Module &M);

bool LooksLikeCodeInBug11395(Instruction *I);
bool GlobalIsLinkerInitialized(GlobalVariable *G);
bool isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis, Value *Addr,
                  uint64_t TypeSize) const;

/// Helper to cleanup per-function state.
struct FunctionStateRAII {
  AddressSanitizer *Pass;

  FunctionStateRAII(AddressSanitizer *Pass) : Pass(Pass) {
    assert(Pass->ProcessedAllocas.empty() &&(static_cast<void> (0))
           "last pass forgot to clear cache")(static_cast<void> (0));
    assert(!Pass->LocalDynamicShadow)(static_cast<void> (0));
  }

  ~FunctionStateRAII() {
    Pass->LocalDynamicShadow = nullptr;
    Pass->ProcessedAllocas.clear();
  }
};

LLVMContext *C;
Triple TargetTriple;
int LongSize;
bool CompileKernel;
bool Recover;
bool UseAfterScope;
AsanDetectStackUseAfterReturnMode UseAfterReturn;
Type *IntptrTy;
Type *Int8PtrTy;
Type *Int32Ty;
ShadowMapping Mapping;
FunctionCallee AsanHandleNoReturnFunc;
FunctionCallee AsanPtrCmpFunction, AsanPtrSubFunction;
Constant *AsanShadowGlobal;

// These arrays is indexed by AccessIsWrite, Experiment and log2(AccessSize).
FunctionCallee AsanErrorCallback[2][2][kNumberOfAccessSizes];
FunctionCallee AsanMemoryAccessCallback[2][2][kNumberOfAccessSizes];

// These arrays is indexed by AccessIsWrite and Experiment.
FunctionCallee AsanErrorCallbackSized[2][2];
FunctionCallee AsanMemoryAccessCallbackSized[2][2];

FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
Value *LocalDynamicShadow = nullptr;
const GlobalsMetadata &GlobalsMD;
DenseMap<const AllocaInst *, bool> ProcessedAllocas;

FunctionCallee AMDGPUAddressShared;
FunctionCallee AMDGPUAddressPrivate;
778};

780class AddressSanitizerLegacyPass : public FunctionPass {
781public:
static char ID;

explicit AddressSanitizerLegacyPass(
    bool CompileKernel = false, bool Recover = false,
    bool UseAfterScope = false,
    AsanDetectStackUseAfterReturnMode UseAfterReturn =
        AsanDetectStackUseAfterReturnMode::Runtime)
    : FunctionPass(ID), CompileKernel(CompileKernel), Recover(Recover),
      UseAfterScope(UseAfterScope), UseAfterReturn(UseAfterReturn) {
  initializeAddressSanitizerLegacyPassPass(*PassRegistry::getPassRegistry());
}

StringRef getPassName() const override {
  return "AddressSanitizerFunctionPass";
}

void getAnalysisUsage(AnalysisUsage &AU) const override {
  AU.addRequired<ASanGlobalsMetadataWrapperPass>();
  AU.addRequired<TargetLibraryInfoWrapperPass>();
}

bool runOnFunction(Function &F) override {
  GlobalsMetadata &GlobalsMD =
      getAnalysis<ASanGlobalsMetadataWrapperPass>().getGlobalsMD();
  const TargetLibraryInfo *TLI =
      &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
  AddressSanitizer ASan(*F.getParent(), &GlobalsMD, CompileKernel, Recover,
                        UseAfterScope, UseAfterReturn);
  return ASan.instrumentFunction(F, TLI);
}

813private:
bool CompileKernel;
bool Recover;
bool UseAfterScope;
AsanDetectStackUseAfterReturnMode UseAfterReturn;
818};

820class ModuleAddressSanitizer {
821public:
ModuleAddressSanitizer(Module &M, const GlobalsMetadata *GlobalsMD,
                       bool CompileKernel = false, bool Recover = false,
                       bool UseGlobalsGC = true, bool UseOdrIndicator = false,
                       AsanDtorKind DestructorKind = AsanDtorKind::Global)
    : GlobalsMD(*GlobalsMD),
      CompileKernel(ClEnableKasan.getNumOccurrences() > 0 ? ClEnableKasan
                                                          : CompileKernel),
      Recover(ClRecover.getNumOccurrences() > 0 ? ClRecover : Recover),
      UseGlobalsGC(UseGlobalsGC && ClUseGlobalsGC && !this->CompileKernel),
      // Enable aliases as they should have no downside with ODR indicators.
      UsePrivateAlias(UseOdrIndicator || ClUsePrivateAlias),
      UseOdrIndicator(UseOdrIndicator || ClUseOdrIndicator),
      // Not a typo: ClWithComdat is almost completely pointless without
      // ClUseGlobalsGC (because then it only works on modules without
      // globals, which are rare); it is a prerequisite for ClUseGlobalsGC;
      // and both suffer from gold PR19002 for which UseGlobalsGC constructor
      // argument is designed as workaround. Therefore, disable both
      // ClWithComdat and ClUseGlobalsGC unless the frontend says it's ok to
      // do globals-gc.
      UseCtorComdat(UseGlobalsGC && ClWithComdat && !this->CompileKernel),
      DestructorKind(DestructorKind) {
  C = &(M.getContext());
  int LongSize = M.getDataLayout().getPointerSizeInBits();
  IntptrTy = Type::getIntNTy(*C, LongSize);
  TargetTriple = Triple(M.getTargetTriple());
  Mapping = getShadowMapping(TargetTriple, LongSize, this->CompileKernel);

  if (ClOverrideDestructorKind != AsanDtorKind::Invalid)
    this->DestructorKind = ClOverrideDestructorKind;
  assert(this->DestructorKind != AsanDtorKind::Invalid)(static_cast<void> (0));
}

bool instrumentModule(Module &);

856private:
void initializeCallbacks(Module &M);

bool InstrumentGlobals(IRBuilder<> &IRB, Module &M, bool *CtorComdat);
void InstrumentGlobalsCOFF(IRBuilder<> &IRB, Module &M,
                           ArrayRef<GlobalVariable *> ExtendedGlobals,
                           ArrayRef<Constant *> MetadataInitializers);
void InstrumentGlobalsELF(IRBuilder<> &IRB, Module &M,
                          ArrayRef<GlobalVariable *> ExtendedGlobals,
                          ArrayRef<Constant *> MetadataInitializers,
                          const std::string &UniqueModuleId);
void InstrumentGlobalsMachO(IRBuilder<> &IRB, Module &M,
                            ArrayRef<GlobalVariable *> ExtendedGlobals,
                            ArrayRef<Constant *> MetadataInitializers);
void
InstrumentGlobalsWithMetadataArray(IRBuilder<> &IRB, Module &M,
                                   ArrayRef<GlobalVariable *> ExtendedGlobals,
                                   ArrayRef<Constant *> MetadataInitializers);

GlobalVariable *CreateMetadataGlobal(Module &M, Constant *Initializer,
                                     StringRef OriginalName);
void SetComdatForGlobalMetadata(GlobalVariable *G, GlobalVariable *Metadata,
                                StringRef InternalSuffix);
Instruction *CreateAsanModuleDtor(Module &M);

const GlobalVariable *getExcludedAliasedGlobal(const GlobalAlias &GA) const;
bool shouldInstrumentGlobal(GlobalVariable *G) const;
bool ShouldUseMachOGlobalsSection() const;
StringRef getGlobalMetadataSection() const;
void poisonOneInitializer(Function &GlobalInit, GlobalValue *ModuleName);
void createInitializerPoisonCalls(Module &M, GlobalValue *ModuleName);
uint64_t getMinRedzoneSizeForGlobal() const {
  return getRedzoneSizeForScale(Mapping.Scale);
}
uint64_t getRedzoneSizeForGlobal(uint64_t SizeInBytes) const;
int GetAsanVersion(const Module &M) const;

const GlobalsMetadata &GlobalsMD;
bool CompileKernel;
bool Recover;
bool UseGlobalsGC;
bool UsePrivateAlias;
bool UseOdrIndicator;
bool UseCtorComdat;
AsanDtorKind DestructorKind;
Type *IntptrTy;
LLVMContext *C;
Triple TargetTriple;
ShadowMapping Mapping;
FunctionCallee AsanPoisonGlobals;
FunctionCallee AsanUnpoisonGlobals;
FunctionCallee AsanRegisterGlobals;
FunctionCallee AsanUnregisterGlobals;
FunctionCallee AsanRegisterImageGlobals;
FunctionCallee AsanUnregisterImageGlobals;
FunctionCallee AsanRegisterElfGlobals;
FunctionCallee AsanUnregisterElfGlobals;

Function *AsanCtorFunction = nullptr;
Function *AsanDtorFunction = nullptr;
916};

918class ModuleAddressSanitizerLegacyPass : public ModulePass {
919public:
static char ID;

explicit ModuleAddressSanitizerLegacyPass(
    bool CompileKernel = false, bool Recover = false, bool UseGlobalGC = true,
    bool UseOdrIndicator = false,
    AsanDtorKind DestructorKind = AsanDtorKind::Global)
    : ModulePass(ID), CompileKernel(CompileKernel), Recover(Recover),
      UseGlobalGC(UseGlobalGC), UseOdrIndicator(UseOdrIndicator),
      DestructorKind(DestructorKind) {
  initializeModuleAddressSanitizerLegacyPassPass(
      *PassRegistry::getPassRegistry());
}

StringRef getPassName() const override { return "ModuleAddressSanitizer"; }

void getAnalysisUsage(AnalysisUsage &AU) const override {
  AU.addRequired<ASanGlobalsMetadataWrapperPass>();
}

bool runOnModule(Module &M) override {
  GlobalsMetadata &GlobalsMD =
      getAnalysis<ASanGlobalsMetadataWrapperPass>().getGlobalsMD();
  ModuleAddressSanitizer ASanModule(M, &GlobalsMD, CompileKernel, Recover,
                                    UseGlobalGC, UseOdrIndicator,
                                    DestructorKind);
  return ASanModule.instrumentModule(M);
}

948private:
bool CompileKernel;
bool Recover;
bool UseGlobalGC;
bool UseOdrIndicator;
AsanDtorKind DestructorKind;
954};

956// Stack poisoning does not play well with exception handling.
957// When an exception is thrown, we essentially bypass the code
958// that unpoisones the stack. This is why the run-time library has
959// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
960// stack in the interceptor. This however does not work inside the
961// actual function which catches the exception. Most likely because the
962// compiler hoists the load of the shadow value somewhere too high.
963// This causes asan to report a non-existing bug on 453.povray.
964// It sounds like an LLVM bug.
965struct FunctionStackPoisoner : public InstVisitor<FunctionStackPoisoner> {
Function &F;
AddressSanitizer &ASan;
DIBuilder DIB;
LLVMContext *C;
Type *IntptrTy;
Type *IntptrPtrTy;
ShadowMapping Mapping;

SmallVector<AllocaInst *, 16> AllocaVec;
SmallVector<AllocaInst *, 16> StaticAllocasToMoveUp;
SmallVector<Instruction *, 8> RetVec;

FunctionCallee AsanStackMallocFunc[kMaxAsanStackMallocSizeClass + 1],
    AsanStackFreeFunc[kMaxAsanStackMallocSizeClass + 1];
FunctionCallee AsanSetShadowFunc[0x100] = {};
FunctionCallee AsanPoisonStackMemoryFunc, AsanUnpoisonStackMemoryFunc;
FunctionCallee AsanAllocaPoisonFunc, AsanAllocasUnpoisonFunc;

// Stores a place and arguments of poisoning/unpoisoning call for alloca.
struct AllocaPoisonCall {
  IntrinsicInst *InsBefore;
  AllocaInst *AI;
  uint64_t Size;
  bool DoPoison;
};
SmallVector<AllocaPoisonCall, 8> DynamicAllocaPoisonCallVec;
SmallVector<AllocaPoisonCall, 8> StaticAllocaPoisonCallVec;
bool HasUntracedLifetimeIntrinsic = false;

SmallVector<AllocaInst *, 1> DynamicAllocaVec;
SmallVector<IntrinsicInst *, 1> StackRestoreVec;
AllocaInst *DynamicAllocaLayout = nullptr;
IntrinsicInst *LocalEscapeCall = nullptr;

bool HasInlineAsm = false;
bool HasReturnsTwiceCall = false;
bool PoisonStack;

FunctionStackPoisoner(Function &F, AddressSanitizer &ASan)
    : F(F), ASan(ASan), DIB(*F.getParent(), /*AllowUnresolved*/ false),
      C(ASan.C), IntptrTy(ASan.IntptrTy),
      IntptrPtrTy(PointerType::get(IntptrTy, 0)), Mapping(ASan.Mapping),
      PoisonStack(ClStack &&
                  !Triple(F.getParent()->getTargetTriple()).isAMDGPU()) {}

bool runOnFunction() {
  if (!PoisonStack)
    return false;

  if (ClRedzoneByvalArgs)
    copyArgsPassedByValToAllocas();

  // Collect alloca, ret, lifetime instructions etc.
  for (BasicBlock *BB : depth_first(&F.getEntryBlock())) visit(*BB);

  if (AllocaVec.empty() && DynamicAllocaVec.empty()) return false;

  initializeCallbacks(*F.getParent());

  if (HasUntracedLifetimeIntrinsic) {
    // If there are lifetime intrinsics which couldn't be traced back to an
    // alloca, we may not know exactly when a variable enters scope, and
    // therefore should "fail safe" by not poisoning them.
    StaticAllocaPoisonCallVec.clear();
    DynamicAllocaPoisonCallVec.clear();
  }

  processDynamicAllocas();
  processStaticAllocas();

  if (ClDebugStack) {
    LLVM_DEBUG(dbgs() << F)do { } while (false);
  }
  return true;
}

// Arguments marked with the "byval" attribute are implicitly copied without
// using an alloca instruction.  To produce redzones for those arguments, we
// copy them a second time into memory allocated with an alloca instruction.
void copyArgsPassedByValToAllocas();

// Finds all Alloca instructions and puts
// poisoned red zones around all of them.
// Then unpoison everything back before the function returns.
void processStaticAllocas();
void processDynamicAllocas();

void createDynamicAllocasInitStorage();

// ----------------------- Visitors.
/// Collect all Ret instructions, or the musttail call instruction if it
/// precedes the return instruction.
void visitReturnInst(ReturnInst &RI) {
  if (CallInst *CI = RI.getParent()->getTerminatingMustTailCall())
    RetVec.push_back(CI);
  else
    RetVec.push_back(&RI);
}

/// Collect all Resume instructions.
void visitResumeInst(ResumeInst &RI) { RetVec.push_back(&RI); }

/// Collect all CatchReturnInst instructions.
void visitCleanupReturnInst(CleanupReturnInst &CRI) { RetVec.push_back(&CRI); }

void unpoisonDynamicAllocasBeforeInst(Instruction *InstBefore,
                                      Value *SavedStack) {
  IRBuilder<> IRB(InstBefore);
  Value *DynamicAreaPtr = IRB.CreatePtrToInt(SavedStack, IntptrTy);
  // When we insert _asan_allocas_unpoison before @llvm.stackrestore, we
  // need to adjust extracted SP to compute the address of the most recent
  // alloca. We have a special @llvm.get.dynamic.area.offset intrinsic for
  // this purpose.
  if (!isa<ReturnInst>(InstBefore)) {
    Function *DynamicAreaOffsetFunc = Intrinsic::getDeclaration(
        InstBefore->getModule(), Intrinsic::get_dynamic_area_offset,
        {IntptrTy});

    Value *DynamicAreaOffset = IRB.CreateCall(DynamicAreaOffsetFunc, {});

    DynamicAreaPtr = IRB.CreateAdd(IRB.CreatePtrToInt(SavedStack, IntptrTy),
                                   DynamicAreaOffset);
  }

  IRB.CreateCall(
      AsanAllocasUnpoisonFunc,
      {IRB.CreateLoad(IntptrTy, DynamicAllocaLayout), DynamicAreaPtr});
}

// Unpoison dynamic allocas redzones.
void unpoisonDynamicAllocas() {
  for (Instruction *Ret : RetVec)
    unpoisonDynamicAllocasBeforeInst(Ret, DynamicAllocaLayout);

  for (Instruction *StackRestoreInst : StackRestoreVec)
    unpoisonDynamicAllocasBeforeInst(StackRestoreInst,
                                     StackRestoreInst->getOperand(0));
}

// Deploy and poison redzones around dynamic alloca call. To do this, we
// should replace this call with another one with changed parameters and
// replace all its uses with new address, so
//   addr = alloca type, old_size, align
// is replaced by
//   new_size = (old_size + additional_size) * sizeof(type)
//   tmp = alloca i8, new_size, max(align, 32)
//   addr = tmp + 32 (first 32 bytes are for the left redzone).
// Additional_size is added to make new memory allocation contain not only
// requested memory, but also left, partial and right redzones.
void handleDynamicAllocaCall(AllocaInst *AI);

/// Collect Alloca instructions we want (and can) handle.
void visitAllocaInst(AllocaInst &AI) {
  if (!ASan.isInterestingAlloca(AI)) {
    if (AI.isStaticAlloca()) {
      // Skip over allocas that are present *before* the first instrumented
      // alloca, we don't want to move those around.
      if (AllocaVec.empty())
        return;

      StaticAllocasToMoveUp.push_back(&AI);
    }
    return;
  }

  if (!AI.isStaticAlloca())
    DynamicAllocaVec.push_back(&AI);
  else
    AllocaVec.push_back(&AI);
}

/// Collect lifetime intrinsic calls to check for use-after-scope
/// errors.
void visitIntrinsicInst(IntrinsicInst &II) {
  Intrinsic::ID ID = II.getIntrinsicID();
  if (ID == Intrinsic::stackrestore) StackRestoreVec.push_back(&II);
1
Assuming 'ID' is not equal to stackrestore→
2
←
Taking false branch→
  if (ID == Intrinsic::localescape) LocalEscapeCall = &II;
3
←
Assuming 'ID' is not equal to localescape→
4
←
Taking false branch→
  if (!ASan.UseAfterScope)
5
←
Assuming field 'UseAfterScope' is true→
6
←
Taking false branch→
    return;
  if (!II.isLifetimeStartOrEnd())
7
←
Assuming the condition is false→
8
←
Taking false branch→
    return;
  // Found lifetime intrinsic, add ASan instrumentation if necessary.
  auto *Size = cast<ConstantInt>(II.getArgOperand(0));
  // If size argument is undefined, don't do anything.
  if (Size->isMinusOne()) return;
9
←
Taking false branch→
  // Check that size doesn't saturate uint64_t and can
  // be stored in IntptrTy.
  const uint64_t SizeValue = Size->getValue().getLimitedValue();
  if (SizeValue == ~0ULL ||
10
←
Assuming the condition is false→
12
←
Taking false branch→
      !ConstantInt::isValueValidForType(IntptrTy, SizeValue))
11
←
Assuming the condition is false→
    return;
  // Find alloca instruction that corresponds to llvm.lifetime argument.
  // Currently we can only handle lifetime markers pointing to the
  // beginning of the alloca.
  AllocaInst *AI = findAllocaForValue(II.getArgOperand(1), true);
  if (!AI) {
13
←
Assuming 'AI' is non-null→
14
←
Taking false branch→
    HasUntracedLifetimeIntrinsic = true;
    return;
  }
  // We're interested only in allocas we can handle.
  if (!ASan.isInterestingAlloca(*AI))
15
←
Calling 'AddressSanitizer::isInterestingAlloca'→
    return;
  bool DoPoison = (ID == Intrinsic::lifetime_end);
  AllocaPoisonCall APC = {&II, AI, SizeValue, DoPoison};
  if (AI->isStaticAlloca())
    StaticAllocaPoisonCallVec.push_back(APC);
  else if (ClInstrumentDynamicAllocas)
    DynamicAllocaPoisonCallVec.push_back(APC);
}

void visitCallBase(CallBase &CB) {
  if (CallInst *CI = dyn_cast<CallInst>(&CB)) {
    HasInlineAsm |= CI->isInlineAsm() && &CB != ASan.LocalDynamicShadow;
    HasReturnsTwiceCall |= CI->canReturnTwice();
  }
}

// ---------------------- Helpers.
void initializeCallbacks(Module &M);

// Copies bytes from ShadowBytes into shadow memory for indexes where
// ShadowMask is not zero. If ShadowMask[i] is zero, we assume that
// ShadowBytes[i] is constantly zero and doesn't need to be overwritten.
void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
                  IRBuilder<> &IRB, Value *ShadowBase);
void copyToShadow(ArrayRef<uint8_t> ShadowMask, ArrayRef<uint8_t> ShadowBytes,
                  size_t Begin, size_t End, IRBuilder<> &IRB,
                  Value *ShadowBase);
void copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
                        ArrayRef<uint8_t> ShadowBytes, size_t Begin,
                        size_t End, IRBuilder<> &IRB, Value *ShadowBase);

void poisonAlloca(Value *V, uint64_t Size, IRBuilder<> &IRB, bool DoPoison);

Value *createAllocaForLayout(IRBuilder<> &IRB, const ASanStackFrameLayout &L,
                             bool Dynamic);
PHINode *createPHI(IRBuilder<> &IRB, Value *Cond, Value *ValueIfTrue,
                   Instruction *ThenTerm, Value *ValueIfFalse);
1204};

1206} // end anonymous namespace

1208void LocationMetadata::parse(MDNode *MDN) {
assert(MDN->getNumOperands() == 3)(static_cast<void> (0));
MDString *DIFilename = cast<MDString>(MDN->getOperand(0));
Filename = DIFilename->getString();
LineNo = mdconst::extract<ConstantInt>(MDN->getOperand(1))->getLimitedValue();
ColumnNo =
    mdconst::extract<ConstantInt>(MDN->getOperand(2))->getLimitedValue();
1215}

1217// FIXME: It would be cleaner to instead attach relevant metadata to the globals
1218// we want to sanitize instead and reading this metadata on each pass over a
1219// function instead of reading module level metadata at first.
1220GlobalsMetadata::GlobalsMetadata(Module &M) {
NamedMDNode *Globals = M.getNamedMetadata("llvm.asan.globals");
if (!Globals)
  return;
for (auto MDN : Globals->operands()) {
  // Metadata node contains the global and the fields of "Entry".
  assert(MDN->getNumOperands() == 5)(static_cast<void> (0));
  auto *V = mdconst::extract_or_null<Constant>(MDN->getOperand(0));
  // The optimizer may optimize away a global entirely.
  if (!V)
    continue;
  auto *StrippedV = V->stripPointerCasts();
  auto *GV = dyn_cast<GlobalVariable>(StrippedV);
  if (!GV)
    continue;
  // We can already have an entry for GV if it was merged with another
  // global.
  Entry &E = Entries[GV];
  if (auto *Loc = cast_or_null<MDNode>(MDN->getOperand(1)))
    E.SourceLoc.parse(Loc);
  if (auto *Name = cast_or_null<MDString>(MDN->getOperand(2)))
    E.Name = Name->getString();
  ConstantInt *IsDynInit = mdconst::extract<ConstantInt>(MDN->getOperand(3));
  E.IsDynInit |= IsDynInit->isOne();
  ConstantInt *IsExcluded =
      mdconst::extract<ConstantInt>(MDN->getOperand(4));
  E.IsExcluded |= IsExcluded->isOne();
}
1248}

1250AnalysisKey ASanGlobalsMetadataAnalysis::Key;

1252GlobalsMetadata ASanGlobalsMetadataAnalysis::run(Module &M,
                                               ModuleAnalysisManager &AM) {
return GlobalsMetadata(M);
1255}

1257PreservedAnalyses AddressSanitizerPass::run(Function &F,
                                          AnalysisManager<Function> &AM) {
auto &MAMProxy = AM.getResult<ModuleAnalysisManagerFunctionProxy>(F);
Module &M = *F.getParent();
if (auto *R = MAMProxy.getCachedResult<ASanGlobalsMetadataAnalysis>(M)) {
  const TargetLibraryInfo *TLI = &AM.getResult<TargetLibraryAnalysis>(F);
  AddressSanitizer Sanitizer(M, R, Options.CompileKernel, Options.Recover,
                             Options.UseAfterScope, Options.UseAfterReturn);
  if (Sanitizer.instrumentFunction(F, TLI))
    return PreservedAnalyses::none();
  return PreservedAnalyses::all();
}

report_fatal_error(
    "The ASanGlobalsMetadataAnalysis is required to run before "
    "AddressSanitizer can run");
return PreservedAnalyses::all();
1274}

1276ModuleAddressSanitizerPass::ModuleAddressSanitizerPass(
  bool CompileKernel, bool Recover, bool UseGlobalGC, bool UseOdrIndicator,
  AsanDtorKind DestructorKind)
  : CompileKernel(CompileKernel), Recover(Recover), UseGlobalGC(UseGlobalGC),
    UseOdrIndicator(UseOdrIndicator), DestructorKind(DestructorKind) {}

1282PreservedAnalyses ModuleAddressSanitizerPass::run(Module &M,
                                                AnalysisManager<Module> &AM) {
GlobalsMetadata &GlobalsMD = AM.getResult<ASanGlobalsMetadataAnalysis>(M);
ModuleAddressSanitizer Sanitizer(M, &GlobalsMD, CompileKernel, Recover,
                                 UseGlobalGC, UseOdrIndicator,
                                 DestructorKind);
if (Sanitizer.instrumentModule(M))
  return PreservedAnalyses::none();
return PreservedAnalyses::all();
1291}

1293INITIALIZE_PASS(ASanGlobalsMetadataWrapperPass, "asan-globals-md",static void *initializeASanGlobalsMetadataWrapperPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "Read metadata to mark which globals should be instrumented "
 "when running ASan.", "asan-globals-md", &ASanGlobalsMetadataWrapperPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ASanGlobalsMetadataWrapperPass
>), false, true); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeASanGlobalsMetadataWrapperPassPassFlag
; void llvm::initializeASanGlobalsMetadataWrapperPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeASanGlobalsMetadataWrapperPassPassFlag
, initializeASanGlobalsMetadataWrapperPassPassOnce, std::ref(
Registry)); }
              "Read metadata to mark which globals should be instrumented "static void *initializeASanGlobalsMetadataWrapperPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "Read metadata to mark which globals should be instrumented "
 "when running ASan.", "asan-globals-md", &ASanGlobalsMetadataWrapperPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ASanGlobalsMetadataWrapperPass
>), false, true); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeASanGlobalsMetadataWrapperPassPassFlag
; void llvm::initializeASanGlobalsMetadataWrapperPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeASanGlobalsMetadataWrapperPassPassFlag
, initializeASanGlobalsMetadataWrapperPassPassOnce, std::ref(
Registry)); }
              "when running ASan.",static void *initializeASanGlobalsMetadataWrapperPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "Read metadata to mark which globals should be instrumented "
 "when running ASan.", "asan-globals-md", &ASanGlobalsMetadataWrapperPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ASanGlobalsMetadataWrapperPass
>), false, true); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeASanGlobalsMetadataWrapperPassPassFlag
; void llvm::initializeASanGlobalsMetadataWrapperPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeASanGlobalsMetadataWrapperPassPassFlag
, initializeASanGlobalsMetadataWrapperPassPassOnce, std::ref(
Registry)); }
              false, true)static void *initializeASanGlobalsMetadataWrapperPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "Read metadata to mark which globals should be instrumented "
 "when running ASan.", "asan-globals-md", &ASanGlobalsMetadataWrapperPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ASanGlobalsMetadataWrapperPass
>), false, true); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeASanGlobalsMetadataWrapperPassPassFlag
; void llvm::initializeASanGlobalsMetadataWrapperPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeASanGlobalsMetadataWrapperPassPassFlag
, initializeASanGlobalsMetadataWrapperPassPassOnce, std::ref(
Registry)); }

1298char AddressSanitizerLegacyPass::ID = 0;

1300INITIALIZE_PASS_BEGIN(static void *initializeAddressSanitizerLegacyPassPassOnce(PassRegistry
 &Registry) {
  AddressSanitizerLegacyPass, "asan",static void *initializeAddressSanitizerLegacyPassPassOnce(PassRegistry
 &Registry) {
  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,static void *initializeAddressSanitizerLegacyPassPassOnce(PassRegistry
 &Registry) {
  false)static void *initializeAddressSanitizerLegacyPassPassOnce(PassRegistry
 &Registry) {
1304INITIALIZE_PASS_DEPENDENCY(ASanGlobalsMetadataWrapperPass)initializeASanGlobalsMetadataWrapperPassPass(Registry);
1305INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry);
1306INITIALIZE_PASS_END(PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
, "asan", &AddressSanitizerLegacyPass::ID, PassInfo::NormalCtor_t
(callDefaultCtor<AddressSanitizerLegacyPass>), false, false
); Registry.registerPass(*PI, true); return PI; } static llvm
::once_flag InitializeAddressSanitizerLegacyPassPassFlag; void
 llvm::initializeAddressSanitizerLegacyPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeAddressSanitizerLegacyPassPassFlag
, initializeAddressSanitizerLegacyPassPassOnce, std::ref(Registry
)); }
  AddressSanitizerLegacyPass, "asan",PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
, "asan", &AddressSanitizerLegacyPass::ID, PassInfo::NormalCtor_t
(callDefaultCtor<AddressSanitizerLegacyPass>), false, false
); Registry.registerPass(*PI, true); return PI; } static llvm
::once_flag InitializeAddressSanitizerLegacyPassPassFlag; void
 llvm::initializeAddressSanitizerLegacyPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeAddressSanitizerLegacyPassPassFlag
, initializeAddressSanitizerLegacyPassPassOnce, std::ref(Registry
)); }
  "AddressSanitizer: detects use-after-free and out-of-bounds bugs.", false,PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
, "asan", &AddressSanitizerLegacyPass::ID, PassInfo::NormalCtor_t
(callDefaultCtor<AddressSanitizerLegacyPass>), false, false
); Registry.registerPass(*PI, true); return PI; } static llvm
::once_flag InitializeAddressSanitizerLegacyPassPassFlag; void
 llvm::initializeAddressSanitizerLegacyPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeAddressSanitizerLegacyPassPassFlag
, initializeAddressSanitizerLegacyPassPassOnce, std::ref(Registry
)); }
  false)PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
, "asan", &AddressSanitizerLegacyPass::ID, PassInfo::NormalCtor_t
(callDefaultCtor<AddressSanitizerLegacyPass>), false, false
); Registry.registerPass(*PI, true); return PI; } static llvm
::once_flag InitializeAddressSanitizerLegacyPassPassFlag; void
 llvm::initializeAddressSanitizerLegacyPassPass(PassRegistry &
Registry) { llvm::call_once(InitializeAddressSanitizerLegacyPassPassFlag
, initializeAddressSanitizerLegacyPassPassOnce, std::ref(Registry
)); }

1311FunctionPass *llvm::createAddressSanitizerFunctionPass(
  bool CompileKernel, bool Recover, bool UseAfterScope,
  AsanDetectStackUseAfterReturnMode UseAfterReturn) {
assert(!CompileKernel || Recover)(static_cast<void> (0));
return new AddressSanitizerLegacyPass(CompileKernel, Recover, UseAfterScope,
                                      UseAfterReturn);
1317}

1319char ModuleAddressSanitizerLegacyPass::ID = 0;

1321INITIALIZE_PASS(static void *initializeModuleAddressSanitizerLegacyPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
 "ModulePass", "asan-module", &ModuleAddressSanitizerLegacyPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ModuleAddressSanitizerLegacyPass
>), false, false); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeModuleAddressSanitizerLegacyPassPassFlag
; void llvm::initializeModuleAddressSanitizerLegacyPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeModuleAddressSanitizerLegacyPassPassFlag
, initializeModuleAddressSanitizerLegacyPassPassOnce, std::ref
(Registry)); }
  ModuleAddressSanitizerLegacyPass, "asan-module",static void *initializeModuleAddressSanitizerLegacyPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
 "ModulePass", "asan-module", &ModuleAddressSanitizerLegacyPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ModuleAddressSanitizerLegacyPass
>), false, false); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeModuleAddressSanitizerLegacyPassPassFlag
; void llvm::initializeModuleAddressSanitizerLegacyPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeModuleAddressSanitizerLegacyPassPassFlag
, initializeModuleAddressSanitizerLegacyPassPassOnce, std::ref
(Registry)); }
  "AddressSanitizer: detects use-after-free and out-of-bounds bugs."static void *initializeModuleAddressSanitizerLegacyPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
 "ModulePass", "asan-module", &ModuleAddressSanitizerLegacyPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ModuleAddressSanitizerLegacyPass
>), false, false); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeModuleAddressSanitizerLegacyPassPassFlag
; void llvm::initializeModuleAddressSanitizerLegacyPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeModuleAddressSanitizerLegacyPassPassFlag
, initializeModuleAddressSanitizerLegacyPassPassOnce, std::ref
(Registry)); }
  "ModulePass",static void *initializeModuleAddressSanitizerLegacyPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
 "ModulePass", "asan-module", &ModuleAddressSanitizerLegacyPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ModuleAddressSanitizerLegacyPass
>), false, false); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeModuleAddressSanitizerLegacyPassPassFlag
; void llvm::initializeModuleAddressSanitizerLegacyPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeModuleAddressSanitizerLegacyPassPassFlag
, initializeModuleAddressSanitizerLegacyPassPassOnce, std::ref
(Registry)); }
  false, false)static void *initializeModuleAddressSanitizerLegacyPassPassOnce
(PassRegistry &Registry) { PassInfo *PI = new PassInfo( "AddressSanitizer: detects use-after-free and out-of-bounds bugs."
 "ModulePass", "asan-module", &ModuleAddressSanitizerLegacyPass
::ID, PassInfo::NormalCtor_t(callDefaultCtor<ModuleAddressSanitizerLegacyPass
>), false, false); Registry.registerPass(*PI, true); return
 PI; } static llvm::once_flag InitializeModuleAddressSanitizerLegacyPassPassFlag
; void llvm::initializeModuleAddressSanitizerLegacyPassPass(PassRegistry
 &Registry) { llvm::call_once(InitializeModuleAddressSanitizerLegacyPassPassFlag
, initializeModuleAddressSanitizerLegacyPassPassOnce, std::ref
(Registry)); }

1327ModulePass *llvm::createModuleAddressSanitizerLegacyPassPass(
  bool CompileKernel, bool Recover, bool UseGlobalsGC, bool UseOdrIndicator,
  AsanDtorKind Destructor) {
assert(!CompileKernel || Recover)(static_cast<void> (0));
return new ModuleAddressSanitizerLegacyPass(
    CompileKernel, Recover, UseGlobalsGC, UseOdrIndicator, Destructor);
1333}

1335static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
size_t Res = countTrailingZeros(TypeSize / 8);
assert(Res < kNumberOfAccessSizes)(static_cast<void> (0));
return Res;
1339}

1341/// Create a global describing a source location.
1342static GlobalVariable *createPrivateGlobalForSourceLoc(Module &M,
                                                     LocationMetadata MD) {
Constant *LocData[] = {
    createPrivateGlobalForString(M, MD.Filename, true, kAsanGenPrefix),
    ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.LineNo),
    ConstantInt::get(Type::getInt32Ty(M.getContext()), MD.ColumnNo),
};
auto LocStruct = ConstantStruct::getAnon(LocData);
auto GV = new GlobalVariable(M, LocStruct->getType(), true,
                             GlobalValue::PrivateLinkage, LocStruct,
                             kAsanGenPrefix);
GV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
return GV;
1355}

1357/// Check if \p G has been created by a trusted compiler pass.
1358static bool GlobalWasGeneratedByCompiler(GlobalVariable *G) {
// Do not instrument @llvm.global_ctors, @llvm.used, etc.
if (G->getName().startswith("llvm."))
  return true;

// Do not instrument asan globals.
if (G->getName().startswith(kAsanGenPrefix) ||
    G->getName().startswith(kSanCovGenPrefix) ||
    G->getName().startswith(kODRGenPrefix))
  return true;

// Do not instrument gcov counter arrays.
if (G->getName() == "__llvm_gcov_ctr")
  return true;

return false;
1374}

1376static bool isUnsupportedAMDGPUAddrspace(Value *Addr) {
Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
unsigned int AddrSpace = PtrTy->getPointerAddressSpace();
if (AddrSpace == 3 || AddrSpace == 5)
  return true;
return false;
1382}

1384Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
// Shadow >> scale
Shadow = IRB.CreateLShr(Shadow, Mapping.Scale);
if (Mapping.Offset == 0) return Shadow;
// (Shadow >> scale) | offset
Value *ShadowBase;
if (LocalDynamicShadow)
  ShadowBase = LocalDynamicShadow;
else
  ShadowBase = ConstantInt::get(IntptrTy, Mapping.Offset);
if (Mapping.OrShadowOffset)
  return IRB.CreateOr(Shadow, ShadowBase);
else
  return IRB.CreateAdd(Shadow, ShadowBase);
1398}

1400// Instrument memset/memmove/memcpy
1401void AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
IRBuilder<> IRB(MI);
if (isa<MemTransferInst>(MI)) {
  IRB.CreateCall(
      isa<MemMoveInst>(MI) ? AsanMemmove : AsanMemcpy,
      {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
       IRB.CreatePointerCast(MI->getOperand(1), IRB.getInt8PtrTy()),
       IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
} else if (isa<MemSetInst>(MI)) {
  IRB.CreateCall(
      AsanMemset,
      {IRB.CreatePointerCast(MI->getOperand(0), IRB.getInt8PtrTy()),
       IRB.CreateIntCast(MI->getOperand(1), IRB.getInt32Ty(), false),
       IRB.CreateIntCast(MI->getOperand(2), IntptrTy, false)});
}
MI->eraseFromParent();
1417}

1419/// Check if we want (and can) handle this alloca.
1420bool AddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
auto PreviouslySeenAllocaInfo = ProcessedAllocas.find(&AI);

if (PreviouslySeenAllocaInfo != ProcessedAllocas.end())
  return PreviouslySeenAllocaInfo->getSecond();

bool IsInteresting =
    (AI.getAllocatedType()->isSized() &&
     // alloca() may be called with 0 size, ignore it.
     ((!AI.isStaticAlloca()) || getAllocaSizeInBytes(AI) > 0) &&
16
←
Assuming the condition is false→
17
←
Calling 'AddressSanitizer::getAllocaSizeInBytes'→
     // We are only interested in allocas not promotable to registers.
     // Promotable allocas are common under -O0.
     (!ClSkipPromotableAllocas || !isAllocaPromotable(&AI)) &&
     // inalloca allocas are not treated as static, and we don't want
     // dynamic alloca instrumentation for them as well.
     !AI.isUsedWithInAlloca() &&
     // swifterror allocas are register promoted by ISel
     !AI.isSwiftError());

ProcessedAllocas[&AI] = IsInteresting;
return IsInteresting;
1441}

1443bool AddressSanitizer::ignoreAccess(Value *Ptr) {
// Instrument acesses from different address spaces only for AMDGPU.
Type *PtrTy = cast<PointerType>(Ptr->getType()->getScalarType());
if (PtrTy->getPointerAddressSpace() != 0 &&
    !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(Ptr)))
  return true;

// Ignore swifterror addresses.
// swifterror memory addresses are mem2reg promoted by instruction
// selection. As such they cannot have regular uses like an instrumentation
// function and it makes no sense to track them as memory.
if (Ptr->isSwiftError())
  return true;

// Treat memory accesses to promotable allocas as non-interesting since they
// will not cause memory violations. This greatly speeds up the instrumented
// executable at -O0.
if (auto AI = dyn_cast_or_null<AllocaInst>(Ptr))
  if (ClSkipPromotableAllocas && !isInterestingAlloca(*AI))
    return true;

return false;
1465}

1467void AddressSanitizer::getInterestingMemoryOperands(
  Instruction *I, SmallVectorImpl<InterestingMemoryOperand> &Interesting) {
// Skip memory accesses inserted by another instrumentation.
if (I->hasMetadata("nosanitize"))
  return;

// Do not instrument the load fetching the dynamic shadow address.
if (LocalDynamicShadow == I)
  return;

if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
  if (!ClInstrumentReads || ignoreAccess(LI->getPointerOperand()))
    return;
  Interesting.emplace_back(I, LI->getPointerOperandIndex(), false,
                           LI->getType(), LI->getAlign());
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
  if (!ClInstrumentWrites || ignoreAccess(SI->getPointerOperand()))
    return;
  Interesting.emplace_back(I, SI->getPointerOperandIndex(), true,
                           SI->getValueOperand()->getType(), SI->getAlign());
} else if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
  if (!ClInstrumentAtomics || ignoreAccess(RMW->getPointerOperand()))
    return;
  Interesting.emplace_back(I, RMW->getPointerOperandIndex(), true,
                           RMW->getValOperand()->getType(), None);
} else if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
  if (!ClInstrumentAtomics || ignoreAccess(XCHG->getPointerOperand()))
    return;
  Interesting.emplace_back(I, XCHG->getPointerOperandIndex(), true,
                           XCHG->getCompareOperand()->getType(), None);
} else if (auto CI = dyn_cast<CallInst>(I)) {
  auto *F = CI->getCalledFunction();
  if (F && (F->getName().startswith("llvm.masked.load.") ||
            F->getName().startswith("llvm.masked.store."))) {
    bool IsWrite = F->getName().startswith("llvm.masked.store.");
    // Masked store has an initial operand for the value.
    unsigned OpOffset = IsWrite ? 1 : 0;
    if (IsWrite ? !ClInstrumentWrites : !ClInstrumentReads)
      return;

    auto BasePtr = CI->getOperand(OpOffset);
    if (ignoreAccess(BasePtr))
      return;
    auto Ty = cast<PointerType>(BasePtr->getType())->getElementType();
    MaybeAlign Alignment = Align(1);
    // Otherwise no alignment guarantees. We probably got Undef.
    if (auto *Op = dyn_cast<ConstantInt>(CI->getOperand(1 + OpOffset)))
      Alignment = Op->getMaybeAlignValue();
    Value *Mask = CI->getOperand(2 + OpOffset);
    Interesting.emplace_back(I, OpOffset, IsWrite, Ty, Alignment, Mask);
  } else {
    for (unsigned ArgNo = 0; ArgNo < CI->getNumArgOperands(); ArgNo++) {
      if (!ClInstrumentByval || !CI->isByValArgument(ArgNo) ||
          ignoreAccess(CI->getArgOperand(ArgNo)))
        continue;
      Type *Ty = CI->getParamByValType(ArgNo);
      Interesting.emplace_back(I, ArgNo, false, Ty, Align(1));
    }
  }
}
1527}

1529static bool isPointerOperand(Value *V) {
return V->getType()->isPointerTy() || isa<PtrToIntInst>(V);
1531}

1533// This is a rough heuristic; it may cause both false positives and
1534// false negatives. The proper implementation requires cooperation with
1535// the frontend.
1536static bool isInterestingPointerComparison(Instruction *I) {
if (ICmpInst *Cmp = dyn_cast<ICmpInst>(I)) {
  if (!Cmp->isRelational())
    return false;
} else {
  return false;
}
return isPointerOperand(I->getOperand(0)) &&
       isPointerOperand(I->getOperand(1));
1545}

1547// This is a rough heuristic; it may cause both false positives and
1548// false negatives. The proper implementation requires cooperation with
1549// the frontend.
1550static bool isInterestingPointerSubtraction(Instruction *I) {
if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
  if (BO->getOpcode() != Instruction::Sub)
    return false;
} else {
  return false;
}
return isPointerOperand(I->getOperand(0)) &&
       isPointerOperand(I->getOperand(1));
1559}

1561bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
// If a global variable does not have dynamic initialization we don't
// have to instrument it.  However, if a global does not have initializer
// at all, we assume it has dynamic initializer (in other TU).
//
// FIXME: Metadata should be attched directly to the global directly instead
// of being added to llvm.asan.globals.
return G->hasInitializer() && !GlobalsMD.get(G).IsDynInit;
1569}

1571void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
  Instruction *I) {
IRBuilder<> IRB(I);
FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
for (Value *&i : Param) {
  if (i->getType()->isPointerTy())
    i = IRB.CreatePointerCast(i, IntptrTy);
}
IRB.CreateCall(F, Param);
1581}

1583static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
                              Instruction *InsertBefore, Value *Addr,
                              MaybeAlign Alignment, unsigned Granularity,
                              uint32_t TypeSize, bool IsWrite,
                              Value *SizeArgument, bool UseCalls,
                              uint32_t Exp) {
// Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
// if the data is properly aligned.
if ((TypeSize == 8 || TypeSize == 16 || TypeSize == 32 || TypeSize == 64 ||
     TypeSize == 128) &&
    (!Alignment || *Alignment >= Granularity || *Alignment >= TypeSize / 8))
  return Pass->instrumentAddress(I, InsertBefore, Addr, TypeSize, IsWrite,
                                 nullptr, UseCalls, Exp);
Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeSize,
                                       IsWrite, nullptr, UseCalls, Exp);
1598}

1600static void instrumentMaskedLoadOrStore(AddressSanitizer *Pass,
                                      const DataLayout &DL, Type *IntptrTy,
                                      Value *Mask, Instruction *I,
                                      Value *Addr, MaybeAlign Alignment,
                                      unsigned Granularity, uint32_t TypeSize,
                                      bool IsWrite, Value *SizeArgument,
                                      bool UseCalls, uint32_t Exp) {
auto *VTy = cast<FixedVectorType>(
    cast<PointerType>(Addr->getType())->getElementType());
uint64_t ElemTypeSize = DL.getTypeStoreSizeInBits(VTy->getScalarType());
unsigned Num = VTy->getNumElements();
auto Zero = ConstantInt::get(IntptrTy, 0);
for (unsigned Idx = 0; Idx < Num; ++Idx) {
  Value *InstrumentedAddress = nullptr;
  Instruction *InsertBefore = I;
  if (auto *Vector = dyn_cast<ConstantVector>(Mask)) {
    // dyn_cast as we might get UndefValue
    if (auto *Masked = dyn_cast<ConstantInt>(Vector->getOperand(Idx))) {
      if (Masked->isZero())
        // Mask is constant false, so no instrumentation needed.
        continue;
      // If we have a true or undef value, fall through to doInstrumentAddress
      // with InsertBefore == I
    }
  } else {
    IRBuilder<> IRB(I);
    Value *MaskElem = IRB.CreateExtractElement(Mask, Idx);
    Instruction *ThenTerm = SplitBlockAndInsertIfThen(MaskElem, I, false);
    InsertBefore = ThenTerm;
  }

  IRBuilder<> IRB(InsertBefore);
  InstrumentedAddress =
      IRB.CreateGEP(VTy, Addr, {Zero, ConstantInt::get(IntptrTy, Idx)});
  doInstrumentAddress(Pass, I, InsertBefore, InstrumentedAddress, Alignment,
                      Granularity, ElemTypeSize, IsWrite, SizeArgument,
                      UseCalls, Exp);
}
1638}

1640void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
                                   InterestingMemoryOperand &O, bool UseCalls,
                                   const DataLayout &DL) {
Value *Addr = O.getPtr();

// Optimization experiments.
// The experiments can be used to evaluate potential optimizations that remove
// instrumentation (assess false negatives). Instead of completely removing
// some instrumentation, you set Exp to a non-zero value (mask of optimization
// experiments that want to remove instrumentation of this instruction).
// If Exp is non-zero, this pass will emit special calls into runtime
// (e.g. __asan_report_exp_load1 instead of __asan_report_load1). These calls
// make runtime terminate the program in a special way (with a different
// exit status). Then you run the new compiler on a buggy corpus, collect
// the special terminations (ideally, you don't see them at all -- no false
// negatives) and make the decision on the optimization.
uint32_t Exp = ClForceExperiment;

if (ClOpt && ClOptGlobals) {
  // If initialization order checking is disabled, a simple access to a
  // dynamically initialized global is always valid.
  GlobalVariable *G = dyn_cast<GlobalVariable>(getUnderlyingObject(Addr));
  if (G && (!ClInitializers || GlobalIsLinkerInitialized(G)) &&
      isSafeAccess(ObjSizeVis, Addr, O.TypeSize)) {
    NumOptimizedAccessesToGlobalVar++;
    return;
  }
}

if (ClOpt && ClOptStack) {
  // A direct inbounds access to a stack variable is always valid.
  if (isa<AllocaInst>(getUnderlyingObject(Addr)) &&
      isSafeAccess(ObjSizeVis, Addr, O.TypeSize)) {
    NumOptimizedAccessesToStackVar++;
    return;
  }
}

if (O.IsWrite)
  NumInstrumentedWrites++;
else
  NumInstrumentedReads++;

unsigned Granularity = 1 << Mapping.Scale;
if (O.MaybeMask) {
  instrumentMaskedLoadOrStore(this, DL, IntptrTy, O.MaybeMask, O.getInsn(),
                              Addr, O.Alignment, Granularity, O.TypeSize,
                              O.IsWrite, nullptr, UseCalls, Exp);
} else {
  doInstrumentAddress(this, O.getInsn(), O.getInsn(), Addr, O.Alignment,
                      Granularity, O.TypeSize, O.IsWrite, nullptr, UseCalls,
                      Exp);
}
1693}

1695Instruction *AddressSanitizer::generateCrashCode(Instruction *InsertBefore,
                                               Value *Addr, bool IsWrite,
                                               size_t AccessSizeIndex,
                                               Value *SizeArgument,
                                               uint32_t Exp) {
IRBuilder<> IRB(InsertBefore);
Value *ExpVal = Exp == 0 ? nullptr : ConstantInt::get(IRB.getInt32Ty(), Exp);
CallInst *Call = nullptr;
if (SizeArgument) {
  if (Exp == 0)
    Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][0],
                          {Addr, SizeArgument});
  else
    Call = IRB.CreateCall(AsanErrorCallbackSized[IsWrite][1],
                          {Addr, SizeArgument, ExpVal});
} else {
  if (Exp == 0)
    Call =
        IRB.CreateCall(AsanErrorCallback[IsWrite][0][AccessSizeIndex], Addr);
  else
    Call = IRB.CreateCall(AsanErrorCallback[IsWrite][1][AccessSizeIndex],
                          {Addr, ExpVal});
}

Call->setCannotMerge();
return Call;
1721}

1723Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
                                         Value *ShadowValue,
                                         uint32_t TypeSize) {
size_t Granularity = static_cast<size_t>(1) << Mapping.Scale;
// Addr & (Granularity - 1)
Value *LastAccessedByte =
    IRB.CreateAnd(AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
// (Addr & (Granularity - 1)) + size - 1
if (TypeSize / 8 > 1)
  LastAccessedByte = IRB.CreateAdd(
      LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
// (uint8_t) ((Addr & (Granularity-1)) + size - 1)
LastAccessedByte =
    IRB.CreateIntCast(LastAccessedByte, ShadowValue->getType(), false);
// ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
return IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
1739}

1741Instruction *AddressSanitizer::instrumentAMDGPUAddress(
  Instruction *OrigIns, Instruction *InsertBefore, Value *Addr,
  uint32_t TypeSize, bool IsWrite, Value *SizeArgument) {
// Do not instrument unsupported addrspaces.
if (isUnsupportedAMDGPUAddrspace(Addr))
  return nullptr;
Type *PtrTy = cast<PointerType>(Addr->getType()->getScalarType());
// Follow host instrumentation for global and constant addresses.
if (PtrTy->getPointerAddressSpace() != 0)
  return InsertBefore;
// Instrument generic addresses in supported addressspaces.
IRBuilder<> IRB(InsertBefore);
Value *AddrLong = IRB.CreatePointerCast(Addr, IRB.getInt8PtrTy());
Value *IsShared = IRB.CreateCall(AMDGPUAddressShared, {AddrLong});
Value *IsPrivate = IRB.CreateCall(AMDGPUAddressPrivate, {AddrLong});
Value *IsSharedOrPrivate = IRB.CreateOr(IsShared, IsPrivate);
Value *Cmp = IRB.CreateICmpNE(IRB.getTrue(), IsSharedOrPrivate);
Value *AddrSpaceZeroLanding =
    SplitBlockAndInsertIfThen(Cmp, InsertBefore, false);
InsertBefore = cast<Instruction>(AddrSpaceZeroLanding);
return InsertBefore;
1762}

1764void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
                                       Instruction *InsertBefore, Value *Addr,
                                       uint32_t TypeSize, bool IsWrite,
                                       Value *SizeArgument, bool UseCalls,
                                       uint32_t Exp) {
if (TargetTriple.isAMDGPU()) {
  InsertBefore = instrumentAMDGPUAddress(OrigIns, InsertBefore, Addr,
                                         TypeSize, IsWrite, SizeArgument);
  if (!InsertBefore)
    return;
}

IRBuilder<> IRB(InsertBefore);
size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);

if (UseCalls && ClOptimizeCallbacks) {
  const ASanAccessInfo AccessInfo(IsWrite, CompileKernel, AccessSizeIndex);
  Module *M = IRB.GetInsertBlock()->getParent()->getParent();
  IRB.CreateCall(
      Intrinsic::getDeclaration(M, Intrinsic::asan_check_memaccess),
      {IRB.CreatePointerCast(Addr, Int8PtrTy),
       ConstantInt::get(Int32Ty, AccessInfo.Packed)});
  return;
}

Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
if (UseCalls) {
  if (Exp == 0)
    IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][0][AccessSizeIndex],
                   AddrLong);
  else
    IRB.CreateCall(AsanMemoryAccessCallback[IsWrite][1][AccessSizeIndex],
                   {AddrLong, ConstantInt::get(IRB.getInt32Ty(), Exp)});
  return;
}

Type *ShadowTy =
    IntegerType::get(*C, std::max(8U, TypeSize >> Mapping.Scale));
Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
Value *ShadowPtr = memToShadow(AddrLong, IRB);
Value *CmpVal = Constant::getNullValue(ShadowTy);
Value *ShadowValue =
    IRB.CreateLoad(ShadowTy, IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));

Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
size_t Granularity = 1ULL << Mapping.Scale;
Instruction *CrashTerm = nullptr;

if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
  // We use branch weights for the slow path check, to indicate that the slow
  // path is rarely taken. This seems to be the case for SPEC benchmarks.
  Instruction *CheckTerm = SplitBlockAndInsertIfThen(
      Cmp, InsertBefore, false, MDBuilder(*C).createBranchWeights(1, 100000));
  assert(cast<BranchInst>(CheckTerm)->isUnconditional())(static_cast<void> (0));
  BasicBlock *NextBB = CheckTerm->getSuccessor(0);
  IRB.SetInsertPoint(CheckTerm);
  Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
  if (Recover) {
    CrashTerm = SplitBlockAndInsertIfThen(Cmp2, CheckTerm, false);
  } else {
    BasicBlock *CrashBlock =
      BasicBlock::Create(*C, "", NextBB->getParent(), NextBB);
    CrashTerm = new UnreachableInst(*C, CrashBlock);
    BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
    ReplaceInstWithInst(CheckTerm, NewTerm);
  }
} else {
  CrashTerm = SplitBlockAndInsertIfThen(Cmp, InsertBefore, !Recover);
}

Instruction *Crash = generateCrashCode(CrashTerm, AddrLong, IsWrite,
                                       AccessSizeIndex, SizeArgument, Exp);
Crash->setDebugLoc(OrigIns->getDebugLoc());
1838}

1840// Instrument unusual size or unusual alignment.
1841// We can not do it with a single check, so we do 1-byte check for the first
1842// and the last bytes. We call __asan_report_*_n(addr, real_size) to be able
1843// to report the actual access size.
1844void AddressSanitizer::instrumentUnusualSizeOrAlignment(
  Instruction *I, Instruction *InsertBefore, Value *Addr, uint32_t TypeSize,
  bool IsWrite, Value *SizeArgument, bool UseCalls, uint32_t Exp) {
IRBuilder<> IRB(InsertBefore);
Value *Size = ConstantInt::get(IntptrTy, TypeSize / 8);
Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
if (UseCalls) {
  if (Exp == 0)
    IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][0],
                   {AddrLong, Size});
  else
    IRB.CreateCall(AsanMemoryAccessCallbackSized[IsWrite][1],
                   {AddrLong, Size, ConstantInt::get(IRB.getInt32Ty(), Exp)});
} else {
  Value *LastByte = IRB.CreateIntToPtr(
      IRB.CreateAdd(AddrLong, ConstantInt::get(IntptrTy, TypeSize / 8 - 1)),
      Addr->getType());
  instrumentAddress(I, InsertBefore, Addr, 8, IsWrite, Size, false, Exp);
  instrumentAddress(I, InsertBefore, LastByte, 8, IsWrite, Size, false, Exp);
}
1864}

1866void ModuleAddressSanitizer::poisonOneInitializer(Function &GlobalInit,
                                                GlobalValue *ModuleName) {
// Set up the arguments to our poison/unpoison functions.
IRBuilder<> IRB(&GlobalInit.front(),
                GlobalInit.front().getFirstInsertionPt());

// Add a call to poison all external globals before the given function starts.
Value *ModuleNameAddr = ConstantExpr::getPointerCast(ModuleName, IntptrTy);
IRB.CreateCall(AsanPoisonGlobals, ModuleNameAddr);

// Add calls to unpoison all globals before each return instruction.
for (auto &BB : GlobalInit.getBasicBlockList())
  if (ReturnInst *RI = dyn_cast<ReturnInst>(BB.getTerminator()))
    CallInst::Create(AsanUnpoisonGlobals, "", RI);
1880}

1882void ModuleAddressSanitizer::createInitializerPoisonCalls(
  Module &M, GlobalValue *ModuleName) {
GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
if (!GV)
  return;

ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
if (!CA)
  return;

for (Use &OP : CA->operands()) {
  if (isa<ConstantAggregateZero>(OP)) continue;
  ConstantStruct *CS = cast<ConstantStruct>(OP);

  // Must have a function or null ptr.
  if (Function *F = dyn_cast<Function>(CS->getOperand(1))) {
    if (F->getName() == kAsanModuleCtorName) continue;
    auto *Priority = cast<ConstantInt>(CS->getOperand(0));
    // Don't instrument CTORs that will run before asan.module_ctor.
    if (Priority->getLimitedValue() <= GetCtorAndDtorPriority(TargetTriple))
      continue;
    poisonOneInitializer(*F, ModuleName);
  }
}
1906}

1908const GlobalVariable *
1909ModuleAddressSanitizer::getExcludedAliasedGlobal(const GlobalAlias &GA) const {
// In case this function should be expanded to include rules that do not just
// apply when CompileKernel is true, either guard all existing rules with an
// 'if (CompileKernel) { ... }' or be absolutely sure that all these rules
// should also apply to user space.
assert(CompileKernel && "Only expecting to be called when compiling kernel")(static_cast<void> (0));

const Constant *C = GA.getAliasee();

// When compiling the kernel, globals that are aliased by symbols prefixed
// by "__" are special and cannot be padded with a redzone.
if (GA.getName().startswith("__"))
  return dyn_cast<GlobalVariable>(C->stripPointerCastsAndAliases());

return nullptr;
1924}

1926bool ModuleAddressSanitizer::shouldInstrumentGlobal(GlobalVariable *G) const {
Type *Ty = G->getValueType();
LLVM_DEBUG(dbgs() << "GLOBAL: " << *G << "\n")do { } while (false);

// FIXME: Metadata should be attched directly to the global directly instead
// of being added to llvm.asan.globals.
if (GlobalsMD.get(G).IsExcluded) return false;
if (!Ty->isSized()) return false;
if (!G->hasInitializer()) return false;
// Globals in address space 1 and 4 are supported for AMDGPU.
if (G->getAddressSpace() &&
    !(TargetTriple.isAMDGPU() && !isUnsupportedAMDGPUAddrspace(G)))
  return false;
if (GlobalWasGeneratedByCompiler(G)) return false; // Our own globals.
// Two problems with thread-locals:
//   - The address of the main thread's copy can't be computed at link-time.
//   - Need to poison all copies, not just the main thread's one.
if (G->isThreadLocal()) return false;
// For now, just ignore this Global if the alignment is large.
if (G->getAlignment() > getMinRedzoneSizeForGlobal()) return false;

// For non-COFF targets, only instrument globals known to be defined by this
// TU.
// FIXME: We can instrument comdat globals on ELF if we are using the
// GC-friendly metadata scheme.
if (!TargetTriple.isOSBinFormatCOFF()) {
  if (!G->hasExactDefinition() || G->hasComdat())
    return false;
} else {
  // On COFF, don't instrument non-ODR linkages.
  if (G->isInterposable())
    return false;
}

// If a comdat is present, it must have a selection kind that implies ODR
// semantics: no duplicates, any, or exact match.
if (Comdat *C = G->getComdat()) {
  switch (C->getSelectionKind()) {
  case Comdat::Any:
  case Comdat::ExactMatch:
  case Comdat::NoDeduplicate:
    break;
  case Comdat::Largest:
  case Comdat::SameSize:
    return false;
  }
}

if (G->hasSection()) {
  // The kernel uses explicit sections for mostly special global variables
  // that we should not instrument. E.g. the kernel may rely on their layout
  // without redzones, or remove them at link time ("discard.*"), etc.
  if (CompileKernel)
    return false;

  StringRef Section = G->getSection();

  // Globals from llvm.metadata aren't emitted, do not instrument them.
  if (Section == "llvm.metadata") return false;
  // Do not instrument globals from special LLVM sections.
  if (Section.find("__llvm") != StringRef::npos || Section.find("__LLVM") != StringRef::npos) return false;

  // Do not instrument function pointers to initialization and termination
  // routines: dynamic linker will not properly handle redzones.
  if (Section.startswith(".preinit_array") ||
      Section.startswith(".init_array") ||
      Section.startswith(".fini_array")) {
    return false;
  }

  // Do not instrument user-defined sections (with names resembling
  // valid C identifiers)
  if (TargetTriple.isOSBinFormatELF()) {
    if (llvm::all_of(Section,
                     [](char c) { return llvm::isAlnum(c) || c == '_'; }))
      return false;
  }

  // On COFF, if the section name contains '$', it is highly likely that the
  // user is using section sorting to create an array of globals similar to
  // the way initialization callbacks are registered in .init_array and
  // .CRT$XCU. The ATL also registers things in .ATL$__[azm]. Adding redzones
  // to such globals is counterproductive, because the intent is that they
  // will form an array, and out-of-bounds accesses are expected.
  // See https://github.com/google/sanitizers/issues/305
  // and http://msdn.microsoft.com/en-US/en-en/library/bb918180(v=vs.120).aspx
  if (TargetTriple.isOSBinFormatCOFF() && Section.contains('$')) {
    LLVM_DEBUG(dbgs() << "Ignoring global in sorted section (contains '$'): "do { } while (false)
                      << *G << "\n")do { } while (false);
    return false;
  }

  if (TargetTriple.isOSBinFormatMachO()) {
    StringRef ParsedSegment, ParsedSection;
    unsigned TAA = 0, StubSize = 0;
    bool TAAParsed;
    cantFail(MCSectionMachO::ParseSectionSpecifier(
        Section, ParsedSegment, ParsedSection, TAA, TAAParsed, StubSize));

    // Ignore the globals from the __OBJC section. The ObjC runtime assumes
    // those conform to /usr/lib/objc/runtime.h, so we can't add redzones to
    // them.
    if (ParsedSegment == "__OBJC" ||
        (ParsedSegment == "__DATA" && ParsedSection.startswith("__objc_"))) {
      LLVM_DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G << "\n")do { } while (false);
      return false;
    }
    // See https://github.com/google/sanitizers/issues/32
    // Constant CFString instances are compiled in the following way:
    //  -- the string buffer is emitted into
    //     __TEXT,__cstring,cstring_literals
    //  -- the constant NSConstantString structure referencing that buffer
    //     is placed into __DATA,__cfstring
    // Therefore there's no point in placing redzones into __DATA,__cfstring.
    // Moreover, it causes the linker to crash on OS X 10.7
    if (ParsedSegment == "__DATA" && ParsedSection == "__cfstring") {
      LLVM_DEBUG(dbgs() << "Ignoring CFString: " << *G << "\n")do { } while (false);
      return false;
    }
    // The linker merges the contents of cstring_literals and removes the
    // trailing zeroes.
    if (ParsedSegment == "__TEXT" && (TAA & MachO::S_CSTRING_LITERALS)) {
      LLVM_DEBUG(dbgs() << "Ignoring a cstring literal: " << *G << "\n")do { } while (false);
      return false;
    }
  }
}

if (CompileKernel) {
  // Globals that prefixed by "__" are special and cannot be padded with a
  // redzone.
  if (G->getName().startswith("__"))
    return false;
}

return true;
2062}

2064// On Mach-O platforms, we emit global metadata in a separate section of the
2065// binary in order to allow the linker to properly dead strip. This is only
2066// supported on recent versions of ld64.
2067bool ModuleAddressSanitizer::ShouldUseMachOGlobalsSection() const {
if (!TargetTriple.isOSBinFormatMachO())
  return false;

if (TargetTriple.isMacOSX() && !TargetTriple.isMacOSXVersionLT(10, 11))
  return true;
if (TargetTriple.isiOS() /* or tvOS */ && !TargetTriple.isOSVersionLT(9))
  return true;
if (TargetTriple.isWatchOS() && !TargetTriple.isOSVersionLT(2))
  return true;

return false;
2079}

2081StringRef ModuleAddressSanitizer::getGlobalMetadataSection() const {
switch (TargetTriple.getObjectFormat()) {
case Triple::COFF:  return ".ASAN$GL";
case Triple::ELF:   return "asan_globals";
case Triple::MachO: return "__DATA,__asan_globals,regular";
case Triple::Wasm:
case Triple::GOFF:
case Triple::XCOFF:
  report_fatal_error(
      "ModuleAddressSanitizer not implemented for object file format");
case Triple::UnknownObjectFormat:
  break;
}
llvm_unreachable("unsupported object format")__builtin_unreachable();
2095}

2097void ModuleAddressSanitizer::initializeCallbacks(Module &M) {
IRBuilder<> IRB(*C);

// Declare our poisoning and unpoisoning functions.
AsanPoisonGlobals =
    M.getOrInsertFunction(kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy);
AsanUnpoisonGlobals =
    M.getOrInsertFunction(kAsanUnpoisonGlobalsName, IRB.getVoidTy());

// Declare functions that register/unregister globals.
AsanRegisterGlobals = M.getOrInsertFunction(
    kAsanRegisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);
AsanUnregisterGlobals = M.getOrInsertFunction(
    kAsanUnregisterGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy);

// Declare the functions that find globals in a shared object and then invoke
// the (un)register function on them.
AsanRegisterImageGlobals = M.getOrInsertFunction(
    kAsanRegisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);
AsanUnregisterImageGlobals = M.getOrInsertFunction(
    kAsanUnregisterImageGlobalsName, IRB.getVoidTy(), IntptrTy);

AsanRegisterElfGlobals =
    M.getOrInsertFunction(kAsanRegisterElfGlobalsName, IRB.getVoidTy(),
                          IntptrTy, IntptrTy, IntptrTy);
AsanUnregisterElfGlobals =
    M.getOrInsertFunction(kAsanUnregisterElfGlobalsName, IRB.getVoidTy(),
                          IntptrTy, IntptrTy, IntptrTy);
2125}

2127// Put the metadata and the instrumented global in the same group. This ensures
2128// that the metadata is discarded if the instrumented global is discarded.
2129void ModuleAddressSanitizer::SetComdatForGlobalMetadata(
  GlobalVariable *G, GlobalVariable *Metadata, StringRef InternalSuffix) {
Module &M = *G->getParent();
Comdat *C = G->getComdat();
if (!C) {
  if (!G->hasName()) {
    // If G is unnamed, it must be internal. Give it an artificial name
    // so we can put it in a comdat.
    assert(G->hasLocalLinkage())(static_cast<void> (0));
    G->setName(Twine(kAsanGenPrefix) + "_anon_global");
  }

  if (!InternalSuffix.empty() && G->hasLocalLinkage()) {
    std::string Name = std::string(G->getName());
    Name += InternalSuffix;
    C = M.getOrInsertComdat(Name);
  } else {
    C = M.getOrInsertComdat(G->getName());
  }

  // Make this IMAGE_COMDAT_SELECT_NODUPLICATES on COFF. Also upgrade private
  // linkage to internal linkage so that a symbol table entry is emitted. This
  // is necessary in order to create the comdat group.
  if (TargetTriple.isOSBinFormatCOFF()) {
    C->setSelectionKind(Comdat::NoDeduplicate);
    if (G->hasPrivateLinkage())
      G->setLinkage(GlobalValue::InternalLinkage);
  }
  G->setComdat(C);
}

assert(G->hasComdat())(static_cast<void> (0));
Metadata->setComdat(G->getComdat());
2162}

2164// Create a separate metadata global and put it in the appropriate ASan
2165// global registration section.
2166GlobalVariable *
2167ModuleAddressSanitizer::CreateMetadataGlobal(Module &M, Constant *Initializer,
                                           StringRef OriginalName) {
auto Linkage = TargetTriple.isOSBinFormatMachO()
                   ? GlobalVariable::InternalLinkage
                   : GlobalVariable::PrivateLinkage;
GlobalVariable *Metadata = new GlobalVariable(
    M, Initializer->getType(), false, Linkage, Initializer,
    Twine("__asan_global_") + GlobalValue::dropLLVMManglingEscape(OriginalName));
Metadata->setSection(getGlobalMetadataSection());
return Metadata;
2177}

2179Instruction *ModuleAddressSanitizer::CreateAsanModuleDtor(Module &M) {
AsanDtorFunction = Function::createWithDefaultAttr(
    FunctionType::get(Type::getVoidTy(*C), false),
    GlobalValue::InternalLinkage, 0, kAsanModuleDtorName, &M);
AsanDtorFunction->addFnAttr(Attribute::NoUnwind);
// Ensure Dtor cannot be discarded, even if in a comdat.
appendToUsed(M, {AsanDtorFunction});
BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);

return ReturnInst::Create(*C, AsanDtorBB);
2189}

2191void ModuleAddressSanitizer::InstrumentGlobalsCOFF(
  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
  ArrayRef<Constant *> MetadataInitializers) {
assert(ExtendedGlobals.size() == MetadataInitializers.size())(static_cast<void> (0));
auto &DL = M.getDataLayout();

SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
  Constant *Initializer = MetadataInitializers[i];
  GlobalVariable *G = ExtendedGlobals[i];
  GlobalVariable *Metadata =
      CreateMetadataGlobal(M, Initializer, G->getName());
  MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
  Metadata->setMetadata(LLVMContext::MD_associated, MD);
  MetadataGlobals[i] = Metadata;

  // The MSVC linker always inserts padding when linking incrementally. We
  // cope with that by aligning each struct to its size, which must be a power
  // of two.
  unsigned SizeOfGlobalStruct = DL.getTypeAllocSize(Initializer->getType());
  assert(isPowerOf2_32(SizeOfGlobalStruct) &&(static_cast<void> (0))
         "global metadata will not be padded appropriately")(static_cast<void> (0));
  Metadata->setAlignment(assumeAligned(SizeOfGlobalStruct));

  SetComdatForGlobalMetadata(G, Metadata, "");
}

// Update llvm.compiler.used, adding the new metadata globals. This is
// needed so that during LTO these variables stay alive.
if (!MetadataGlobals.empty())
  appendToCompilerUsed(M, MetadataGlobals);
2222}

2224void ModuleAddressSanitizer::InstrumentGlobalsELF(
  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
  ArrayRef<Constant *> MetadataInitializers,
  const std::string &UniqueModuleId) {
assert(ExtendedGlobals.size() == MetadataInitializers.size())(static_cast<void> (0));

// Putting globals in a comdat changes the semantic and potentially cause
// false negative odr violations at link time. If odr indicators are used, we
// keep the comdat sections, as link time odr violations will be dectected on
// the odr indicator symbols.
bool UseComdatForGlobalsGC = UseOdrIndicator;

SmallVector<GlobalValue *, 16> MetadataGlobals(ExtendedGlobals.size());
for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
  GlobalVariable *G = ExtendedGlobals[i];
  GlobalVariable *Metadata =
      CreateMetadataGlobal(M, MetadataInitializers[i], G->getName());
  MDNode *MD = MDNode::get(M.getContext(), ValueAsMetadata::get(G));
  Metadata->setMetadata(LLVMContext::MD_associated, MD);
  MetadataGlobals[i] = Metadata;

  if (UseComdatForGlobalsGC)
    SetComdatForGlobalMetadata(G, Metadata, UniqueModuleId);
}

// Update llvm.compiler.used, adding the new metadata globals. This is
// needed so that during LTO these variables stay alive.
if (!MetadataGlobals.empty())
  appendToCompilerUsed(M, MetadataGlobals);

// RegisteredFlag serves two purposes. First, we can pass it to dladdr()
// to look up the loaded image that contains it. Second, we can store in it
// whether registration has already occurred, to prevent duplicate
// registration.
//
// Common linkage ensures that there is only one global per shared library.
GlobalVariable *RegisteredFlag = new GlobalVariable(
    M, IntptrTy, false, GlobalVariable::CommonLinkage,
    ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
RegisteredFlag->setVisibility(GlobalVariable::HiddenVisibility);

// Create start and stop symbols.
GlobalVariable *StartELFMetadata = new GlobalVariable(
    M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
    "__start_" + getGlobalMetadataSection());
StartELFMetadata->setVisibility(GlobalVariable::HiddenVisibility);
GlobalVariable *StopELFMetadata = new GlobalVariable(
    M, IntptrTy, false, GlobalVariable::ExternalWeakLinkage, nullptr,
    "__stop_" + getGlobalMetadataSection());
StopELFMetadata->setVisibility(GlobalVariable::HiddenVisibility);

// Create a call to register the globals with the runtime.
IRB.CreateCall(AsanRegisterElfGlobals,
               {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
                IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
                IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});

// We also need to unregister globals at the end, e.g., when a shared library
// gets closed.
if (DestructorKind != AsanDtorKind::None) {
  IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
  IrbDtor.CreateCall(AsanUnregisterElfGlobals,
                     {IRB.CreatePointerCast(RegisteredFlag, IntptrTy),
                      IRB.CreatePointerCast(StartELFMetadata, IntptrTy),
                      IRB.CreatePointerCast(StopELFMetadata, IntptrTy)});
}
2290}

2292void ModuleAddressSanitizer::InstrumentGlobalsMachO(
  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
  ArrayRef<Constant *> MetadataInitializers) {
assert(ExtendedGlobals.size() == MetadataInitializers.size())(static_cast<void> (0));

// On recent Mach-O platforms, use a structure which binds the liveness of
// the global variable to the metadata struct. Keep the list of "Liveness" GV
// created to be added to llvm.compiler.used
StructType *LivenessTy = StructType::get(IntptrTy, IntptrTy);
SmallVector<GlobalValue *, 16> LivenessGlobals(ExtendedGlobals.size());

for (size_t i = 0; i < ExtendedGlobals.size(); i++) {
  Constant *Initializer = MetadataInitializers[i];
  GlobalVariable *G = ExtendedGlobals[i];
  GlobalVariable *Metadata =
      CreateMetadataGlobal(M, Initializer, G->getName());

  // On recent Mach-O platforms, we emit the global metadata in a way that
  // allows the linker to properly strip dead globals.
  auto LivenessBinder =
      ConstantStruct::get(LivenessTy, Initializer->getAggregateElement(0u),
                          ConstantExpr::getPointerCast(Metadata, IntptrTy));
  GlobalVariable *Liveness = new GlobalVariable(
      M, LivenessTy, false, GlobalVariable::InternalLinkage, LivenessBinder,
      Twine("__asan_binder_") + G->getName());
  Liveness->setSection("__DATA,__asan_liveness,regular,live_support");
  LivenessGlobals[i] = Liveness;
}

// Update llvm.compiler.used, adding the new liveness globals. This is
// needed so that during LTO these variables stay alive. The alternative
// would be to have the linker handling the LTO symbols, but libLTO
// current API does not expose access to the section for each symbol.
if (!LivenessGlobals.empty())
  appendToCompilerUsed(M, LivenessGlobals);

// RegisteredFlag serves two purposes. First, we can pass it to dladdr()
// to look up the loaded image that contains it. Second, we can store in it
// whether registration has already occurred, to prevent duplicate
// registration.
//
// common linkage ensures that there is only one global per shared library.
GlobalVariable *RegisteredFlag = new GlobalVariable(
    M, IntptrTy, false, GlobalVariable::CommonLinkage,
    ConstantInt::get(IntptrTy, 0), kAsanGlobalsRegisteredFlagName);
RegisteredFlag->setVisibility(GlobalVariable::HiddenVisibility);

IRB.CreateCall(AsanRegisterImageGlobals,
               {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});

// We also need to unregister globals at the end, e.g., when a shared library
// gets closed.
if (DestructorKind != AsanDtorKind::None) {
  IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
  IrbDtor.CreateCall(AsanUnregisterImageGlobals,
                     {IRB.CreatePointerCast(RegisteredFlag, IntptrTy)});
}
2349}

2351void ModuleAddressSanitizer::InstrumentGlobalsWithMetadataArray(
  IRBuilder<> &IRB, Module &M, ArrayRef<GlobalVariable *> ExtendedGlobals,
  ArrayRef<Constant *> MetadataInitializers) {
assert(ExtendedGlobals.size() == MetadataInitializers.size())(static_cast<void> (0));
unsigned N = ExtendedGlobals.size();
assert(N > 0)(static_cast<void> (0));

// On platforms that don't have a custom metadata section, we emit an array
// of global metadata structures.
ArrayType *ArrayOfGlobalStructTy =
    ArrayType::get(MetadataInitializers[0]->getType(), N);
auto AllGlobals = new GlobalVariable(
    M, ArrayOfGlobalStructTy, false, GlobalVariable::InternalLinkage,
    ConstantArray::get(ArrayOfGlobalStructTy, MetadataInitializers), "");
if (Mapping.Scale > 3)
  AllGlobals->setAlignment(Align(1ULL << Mapping.Scale));

IRB.CreateCall(AsanRegisterGlobals,
               {IRB.CreatePointerCast(AllGlobals, IntptrTy),
                ConstantInt::get(IntptrTy, N)});

// We also need to unregister globals at the end, e.g., when a shared library
// gets closed.
if (DestructorKind != AsanDtorKind::None) {
  IRBuilder<> IrbDtor(CreateAsanModuleDtor(M));
  IrbDtor.CreateCall(AsanUnregisterGlobals,
                     {IRB.CreatePointerCast(AllGlobals, IntptrTy),
                      ConstantInt::get(IntptrTy, N)});
}
2380}

2382// This function replaces all global variables with new variables that have
2383// trailing redzones. It also creates a function that poisons
2384// redzones and inserts this function into llvm.global_ctors.
2385// Sets *CtorComdat to true if the global registration code emitted into the
2386// asan constructor is comdat-compatible.
2387bool ModuleAddressSanitizer::InstrumentGlobals(IRBuilder<> &IRB, Module &M,
                                             bool *CtorComdat) {
*CtorComdat = false;

// Build set of globals that are aliased by some GA, where
// getExcludedAliasedGlobal(GA) returns the relevant GlobalVariable.
SmallPtrSet<const GlobalVariable *, 16> AliasedGlobalExclusions;
if (CompileKernel) {
  for (auto &GA : M.aliases()) {
    if (const GlobalVariable *GV = getExcludedAliasedGlobal(GA))
      AliasedGlobalExclusions.insert(GV);
  }
}

SmallVector<GlobalVariable *, 16> GlobalsToChange;
for (auto &G : M.globals()) {
  if (!AliasedGlobalExclusions.count(&G) && shouldInstrumentGlobal(&G))
    GlobalsToChange.push_back(&G);
}

size_t n = GlobalsToChange.size();
if (n == 0) {
  *CtorComdat = true;
  return false;
}

auto &DL = M.getDataLayout();

// A global is described by a structure
//   size_t beg;
//   size_t size;
//   size_t size_with_redzone;
//   const char *name;
//   const char *module_name;
//   size_t has_dynamic_init;
//   void *source_location;
//   size_t odr_indicator;
// We initialize an array of such structures and pass it to a run-time call.
StructType *GlobalStructTy =
    StructType::get(IntptrTy, IntptrTy, IntptrTy, IntptrTy, IntptrTy,
                    IntptrTy, IntptrTy, IntptrTy);
SmallVector<GlobalVariable *, 16> NewGlobals(n);
SmallVector<Constant *, 16> Initializers(n);

bool HasDynamicallyInitializedGlobals = false;

// We shouldn't merge same module names, as this string serves as unique
// module ID in runtime.
GlobalVariable *ModuleName = createPrivateGlobalForString(
    M, M.getModuleIdentifier(), /*AllowMerging*/ false, kAsanGenPrefix);

for (size_t i = 0; i < n; i++) {
  GlobalVariable *G = GlobalsToChange[i];

  // FIXME: Metadata should be attched directly to the global directly instead
  // of being added to llvm.asan.globals.
  auto MD = GlobalsMD.get(G);
  StringRef NameForGlobal = G->getName();
  // Create string holding the global name (use global name from metadata
  // if it's available, otherwise just write the name of global variable).
  GlobalVariable *Name = createPrivateGlobalForString(
      M, MD.Name.empty() ? NameForGlobal : MD.Name,
      /*AllowMerging*/ true, kAsanGenPrefix);

  Type *Ty = G->getValueType();
  const uint64_t SizeInBytes = DL.getTypeAllocSize(Ty);
  const uint64_t RightRedzoneSize = getRedzoneSizeForGlobal(SizeInBytes);
  Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);

  StructType *NewTy = StructType::get(Ty, RightRedZoneTy);
  Constant *NewInitializer = ConstantStruct::get(
      NewTy, G->getInitializer(), Constant::getNullValue(RightRedZoneTy));

  // Create a new global variable with enough space for a redzone.
  GlobalValue::LinkageTypes Linkage = G->getLinkage();
  if (G->isConstant() && Linkage == GlobalValue::PrivateLinkage)
    Linkage = GlobalValue::InternalLinkage;
  GlobalVariable *NewGlobal = new GlobalVariable(
      M, NewTy, G->isConstant(), Linkage, NewInitializer, "", G,
      G->getThreadLocalMode(), G->getAddressSpace());
  NewGlobal->copyAttributesFrom(G);
  NewGlobal->setComdat(G->getComdat());
  NewGlobal->setAlignment(MaybeAlign(getMinRedzoneSizeForGlobal()));
  // Don't fold globals with redzones. ODR violation detector and redzone
  // poisoning implicitly creates a dependence on the global's address, so it
  // is no longer valid for it to be marked unnamed_addr.
  NewGlobal->setUnnamedAddr(GlobalValue::UnnamedAddr::None);

  // Move null-terminated C strings to "__asan_cstring" section on Darwin.
  if (TargetTriple.isOSBinFormatMachO() && !G->hasSection() &&
      G->isConstant()) {
    auto Seq = dyn_cast<ConstantDataSequential>(G->getInitializer());
    if (Seq && Seq->isCString())
      NewGlobal->setSection("__TEXT,__asan_cstring,regular");
  }

  // Transfer the debug info and type metadata.  The payload starts at offset
  // zero so we can copy the metadata over as is.
  NewGlobal->copyMetadata(G, 0);

  Value *Indices2[2];
  Indices2[0] = IRB.getInt32(0);
  Indices2[1] = IRB.getInt32(0);

  G->replaceAllUsesWith(
      ConstantExpr::getGetElementPtr(NewTy, NewGlobal, Indices2, true));
  NewGlobal->takeName(G);
  G->eraseFromParent();
  NewGlobals[i] = NewGlobal;

  Constant *SourceLoc;
  if (!MD.SourceLoc.empty()) {
    auto SourceLocGlobal = createPrivateGlobalForSourceLoc(M, MD.SourceLoc);
    SourceLoc = ConstantExpr::getPointerCast(SourceLocGlobal, IntptrTy);
  } else {
    SourceLoc = ConstantInt::get(IntptrTy, 0);
  }

  Constant *ODRIndicator = ConstantExpr::getNullValue(IRB.getInt8PtrTy());
  GlobalValue *InstrumentedGlobal = NewGlobal;

  bool CanUsePrivateAliases =
      TargetTriple.isOSBinFormatELF() || TargetTriple.isOSBinFormatMachO() ||
      TargetTriple.isOSBinFormatWasm();
  if (CanUsePrivateAliases && UsePrivateAlias) {
    // Create local alias for NewGlobal to avoid crash on ODR between
    // instrumented and non-instrumented libraries.
    InstrumentedGlobal =
        GlobalAlias::create(GlobalValue::PrivateLinkage, "", NewGlobal);
  }

  // ODR should not happen for local linkage.
  if (NewGlobal->hasLocalLinkage()) {
    ODRIndicator = ConstantExpr::getIntToPtr(ConstantInt::get(IntptrTy, -1),
                                             IRB.getInt8PtrTy());
  } else if (UseOdrIndicator) {
    // With local aliases, we need to provide another externally visible
    // symbol __odr_asan_XXX to detect ODR violation.
    auto *ODRIndicatorSym =
        new GlobalVariable(M, IRB.getInt8Ty(), false, Linkage,
                           Constant::getNullValue(IRB.getInt8Ty()),
                           kODRGenPrefix + NameForGlobal, nullptr,
                           NewGlobal->getThreadLocalMode());

    // Set meaningful attributes for indicator symbol.
    ODRIndicatorSym->setVisibility(NewGlobal->getVisibility());
    ODRIndicatorSym->setDLLStorageClass(NewGlobal->getDLLStorageClass());
    ODRIndicatorSym->setAlignment(Align(1));
    ODRIndicator = ODRIndicatorSym;
  }

  Constant *Initializer = ConstantStruct::get(
      GlobalStructTy,
      ConstantExpr::getPointerCast(InstrumentedGlobal, IntptrTy),
      ConstantInt::get(IntptrTy, SizeInBytes),
      ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
      ConstantExpr::getPointerCast(Name, IntptrTy),
      ConstantExpr::getPointerCast(ModuleName, IntptrTy),
      ConstantInt::get(IntptrTy, MD.IsDynInit), SourceLoc,
      ConstantExpr::getPointerCast(ODRIndicator, IntptrTy));

  if (ClInitializers && MD.IsDynInit) HasDynamicallyInitializedGlobals = true;

  LLVM_DEBUG(dbgs() << "NEW GLOBAL: " << *NewGlobal << "\n")do { } while (false);

  Initializers[i] = Initializer;
}

// Add instrumented globals to llvm.compiler.used list to avoid LTO from
// ConstantMerge'ing them.
SmallVector<GlobalValue *, 16> GlobalsToAddToUsedList;
for (size_t i = 0; i < n; i++) {
  GlobalVariable *G = NewGlobals[i];
  if (G->getName().empty()) continue;
  GlobalsToAddToUsedList.push_back(G);
}
appendToCompilerUsed(M, ArrayRef<GlobalValue *>(GlobalsToAddToUsedList));

std::string ELFUniqueModuleId =
    (UseGlobalsGC && TargetTriple.isOSBinFormatELF()) ? getUniqueModuleId(&M)
                                                      : "";

if (!ELFUniqueModuleId.empty()) {
  InstrumentGlobalsELF(IRB, M, NewGlobals, Initializers, ELFUniqueModuleId);
  *CtorComdat = true;
} else if (UseGlobalsGC && TargetTriple.isOSBinFormatCOFF()) {
  InstrumentGlobalsCOFF(IRB, M, NewGlobals, Initializers);
} else if (UseGlobalsGC && ShouldUseMachOGlobalsSection()) {
  InstrumentGlobalsMachO(IRB, M, NewGlobals, Initializers);
} else {
  InstrumentGlobalsWithMetadataArray(IRB, M, NewGlobals, Initializers);
}

// Create calls for poisoning before initializers run and unpoisoning after.
if (HasDynamicallyInitializedGlobals)
  createInitializerPoisonCalls(M, ModuleName);

LLVM_DEBUG(dbgs() << M)do { } while (false);
return true;
2586}

2588uint64_t
2589ModuleAddressSanitizer::getRedzoneSizeForGlobal(uint64_t SizeInBytes) const {
constexpr uint64_t kMaxRZ = 1 << 18;
const uint64_t MinRZ = getMinRedzoneSizeForGlobal();

uint64_t RZ = 0;
if (SizeInBytes <= MinRZ / 2) {
  // Reduce redzone size for small size objects, e.g. int, char[1]. MinRZ is
  // at least 32 bytes, optimize when SizeInBytes is less than or equal to
  // half of MinRZ.
  RZ = MinRZ - SizeInBytes;
} else {
  // Calculate RZ, where MinRZ <= RZ <= MaxRZ, and RZ ~ 1/4 * SizeInBytes.
  RZ = std::max(MinRZ, std::min(kMaxRZ, (SizeInBytes / MinRZ / 4) * MinRZ));

  // Round up to multiple of MinRZ.
  if (SizeInBytes % MinRZ)
    RZ += MinRZ - (SizeInBytes % MinRZ);
}

assert((RZ + SizeInBytes) % MinRZ == 0)(static_cast<void> (0));

return RZ;
2611}

2613int ModuleAddressSanitizer::GetAsanVersion(const Module &M) const {
int LongSize = M.getDataLayout().getPointerSizeInBits();
bool isAndroid = Triple(M.getTargetTriple()).isAndroid();
int Version = 8;
// 32-bit Android is one version ahead because of the switch to dynamic
// shadow.
Version += (LongSize == 32 && isAndroid);
return Version;
2621}

2623bool ModuleAddressSanitizer::instrumentModule(Module &M) {
initializeCallbacks(M);

// Create a module constructor. A destructor is created lazily because not all
// platforms, and not all modules need it.
if (CompileKernel) {
  // The kernel always builds with its own runtime, and therefore does not
  // need the init and version check calls.
  AsanCtorFunction = createSanitizerCtor(M, kAsanModuleCtorName);
} else {
  std::string AsanVersion = std::to_string(GetAsanVersion(M));
  std::string VersionCheckName =
      ClInsertVersionCheck ? (kAsanVersionCheckNamePrefix + AsanVersion) : "";
  std::tie(AsanCtorFunction, std::ignore) =
      createSanitizerCtorAndInitFunctions(M, kAsanModuleCtorName,
                                          kAsanInitName, /*InitArgTypes=*/{},
                                          /*InitArgs=*/{}, VersionCheckName);
}

bool CtorComdat = true;
if (ClGlobals) {
  IRBuilder<> IRB(AsanCtorFunction->getEntryBlock().getTerminator());
  InstrumentGlobals(IRB, M, &CtorComdat);
}

const uint64_t Priority = GetCtorAndDtorPriority(TargetTriple);

// Put the constructor and destructor in comdat if both
// (1) global instrumentation is not TU-specific
// (2) target is ELF.
if (UseCtorComdat && TargetTriple.isOSBinFormatELF() && CtorComdat) {
  AsanCtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleCtorName));
  appendToGlobalCtors(M, AsanCtorFunction, Priority, AsanCtorFunction);
  if (AsanDtorFunction) {
    AsanDtorFunction->setComdat(M.getOrInsertComdat(kAsanModuleDtorName));
    appendToGlobalDtors(M, AsanDtorFunction, Priority, AsanDtorFunction);
  }
} else {
  appendToGlobalCtors(M, AsanCtorFunction, Priority);
  if (AsanDtorFunction)
    appendToGlobalDtors(M, AsanDtorFunction, Priority);
}

return true;
2667}

2669void AddressSanitizer::initializeCallbacks(Module &M) {
IRBuilder<> IRB(*C);
// Create __asan_report* callbacks.
// IsWrite, TypeSize and Exp are encoded in the function name.
for (int Exp = 0; Exp < 2; Exp++) {
  for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
    const std::string TypeStr = AccessIsWrite ? "store" : "load";
    const std::string ExpStr = Exp ? "exp_" : "";
    const std::string EndingStr = Recover ? "_noabort" : "";

    SmallVector<Type *, 3> Args2 = {IntptrTy, IntptrTy};
    SmallVector<Type *, 2> Args1{1, IntptrTy};
    if (Exp) {
      Type *ExpType = Type::getInt32Ty(*C);
      Args2.push_back(ExpType);
      Args1.push_back(ExpType);
    }
    AsanErrorCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
        kAsanReportErrorTemplate + ExpStr + TypeStr + "_n" + EndingStr,
        FunctionType::get(IRB.getVoidTy(), Args2, false));

    AsanMemoryAccessCallbackSized[AccessIsWrite][Exp] = M.getOrInsertFunction(
        ClMemoryAccessCallbackPrefix + ExpStr + TypeStr + "N" + EndingStr,
        FunctionType::get(IRB.getVoidTy(), Args2, false));

    for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
         AccessSizeIndex++) {
      const std::string Suffix = TypeStr + itostr(1ULL << AccessSizeIndex);
      AsanErrorCallback[AccessIsWrite][Exp][AccessSizeIndex] =
          M.getOrInsertFunction(
              kAsanReportErrorTemplate + ExpStr + Suffix + EndingStr,
              FunctionType::get(IRB.getVoidTy(), Args1, false));

      AsanMemoryAccessCallback[AccessIsWrite][Exp][AccessSizeIndex] =
          M.getOrInsertFunction(
              ClMemoryAccessCallbackPrefix + ExpStr + Suffix + EndingStr,
              FunctionType::get(IRB.getVoidTy(), Args1, false));
    }
  }
}

const std::string MemIntrinCallbackPrefix =
    CompileKernel ? std::string("") : ClMemoryAccessCallbackPrefix;
AsanMemmove = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memmove",
                                    IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
                                    IRB.getInt8PtrTy(), IntptrTy);
AsanMemcpy = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memcpy",
                                   IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
                                   IRB.getInt8PtrTy(), IntptrTy);
AsanMemset = M.getOrInsertFunction(MemIntrinCallbackPrefix + "memset",
                                   IRB.getInt8PtrTy(), IRB.getInt8PtrTy(),
                                   IRB.getInt32Ty(), IntptrTy);

AsanHandleNoReturnFunc =
    M.getOrInsertFunction(kAsanHandleNoReturnName, IRB.getVoidTy());

AsanPtrCmpFunction =
    M.getOrInsertFunction(kAsanPtrCmp, IRB.getVoidTy(), IntptrTy, IntptrTy);
AsanPtrSubFunction =
    M.getOrInsertFunction(kAsanPtrSub, IRB.getVoidTy(), IntptrTy, IntptrTy);
if (Mapping.InGlobal)
  AsanShadowGlobal = M.getOrInsertGlobal("__asan_shadow",
                                         ArrayType::get(IRB.getInt8Ty(), 0));

AMDGPUAddressShared = M.getOrInsertFunction(
    kAMDGPUAddressSharedName, IRB.getInt1Ty(), IRB.getInt8PtrTy());
AMDGPUAddressPrivate = M.getOrInsertFunction(
    kAMDGPUAddressPrivateName, IRB.getInt1Ty(), IRB.getInt8PtrTy());
2737}

2739bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {
// For each NSObject descendant having a +load method, this method is invoked
// by the ObjC runtime before any of the static constructors is called.
// Therefore we need to instrument such methods with a call to __asan_init
// at the beginning in order to initialize our runtime before any access to
// the shadow memory.
// We cannot just ignore these methods, because they may call other
// instrumented functions.
if (F.getName().find(" load]") != std::string::npos) {
  FunctionCallee AsanInitFunction =
      declareSanitizerInitFunction(*F.getParent(), kAsanInitName, {});
  IRBuilder<> IRB(&F.front(), F.front().begin());
  IRB.CreateCall(AsanInitFunction, {});
  return true;
}
return false;
2755}

2757bool AddressSanitizer::maybeInsertDynamicShadowAtFunctionEntry(Function &F) {
// Generate code only when dynamic addressing is needed.
if (Mapping.Offset != kDynamicShadowSentinel)
  return false;

IRBuilder<> IRB(&F.front().front());
if (Mapping.InGlobal) {
  if (ClWithIfuncSuppressRemat) {
    // An empty inline asm with input reg == output reg.
    // An opaque pointer-to-int cast, basically.
    InlineAsm *Asm = InlineAsm::get(
        FunctionType::get(IntptrTy, {AsanShadowGlobal->getType()}, false),
        StringRef(""), StringRef("=r,0"),
        /*hasSideEffects=*/false);
    LocalDynamicShadow =
        IRB.CreateCall(Asm, {AsanShadowGlobal}, ".asan.shadow");
  } else {
    LocalDynamicShadow =
        IRB.CreatePointerCast(AsanShadowGlobal, IntptrTy, ".asan.shadow");
  }
} else {
  Value *GlobalDynamicAddress = F.getParent()->getOrInsertGlobal(
      kAsanShadowMemoryDynamicAddress, IntptrTy);
  LocalDynamicShadow = IRB.CreateLoad(IntptrTy, GlobalDynamicAddress);
}
return true;
2783}

2785void AddressSanitizer::markEscapedLocalAllocas(Function &F) {
// Find the one possible call to llvm.localescape and pre-mark allocas passed
// to it as uninteresting. This assumes we haven't started processing allocas
// yet. This check is done up front because iterating the use list in
// isInterestingAlloca would be algorithmically slower.
assert(ProcessedAllocas.empty() && "must process localescape before allocas")(static_cast<void> (0));

// Try to get the declaration of llvm.localescape. If it's not in the module,
// we can exit early.
if (!F.getParent()->getFunction("llvm.localescape")) return;

// Look for a call to llvm.localescape call in the entry block. It can't be in
// any other block.
for (Instruction &I : F.getEntryBlock()) {
  IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
  if (II && II->getIntrinsicID() == Intrinsic::localescape) {
    // We found a call. Mark all the allocas passed in as uninteresting.
    for (Value *Arg : II->arg_operands()) {
      AllocaInst *AI = dyn_cast<AllocaInst>(Arg->stripPointerCasts());
      assert(AI && AI->isStaticAlloca() &&(static_cast<void> (0))
             "non-static alloca arg to localescape")(static_cast<void> (0));
      ProcessedAllocas[AI] = false;
    }
    break;
  }
}
2811}

2813bool AddressSanitizer::suppressInstrumentationSiteForDebug(int &Instrumented) {
bool ShouldInstrument =
    ClDebugMin < 0 || ClDebugMax < 0 ||
    (Instrumented >= ClDebugMin && Instrumented <= ClDebugMax);
Instrumented++;
return !ShouldInstrument;
2819}

2821bool AddressSanitizer::instrumentFunction(Function &F,
                                        const TargetLibraryInfo *TLI) {
if (F.getLinkage() == GlobalValue::AvailableExternallyLinkage) return false;
if (!ClDebugFunc.empty() && ClDebugFunc == F.getName()) return false;
if (F.getName().startswith("__asan_")) return false;

bool FunctionModified = false;

// If needed, insert __asan_init before checking for SanitizeAddress attr.
// This function needs to be called even if the function body is not
// instrumented.
if (maybeInsertAsanInitAtFunctionEntry(F))
  FunctionModified = true;

// Leave if the function doesn't need instrumentation.
if (!F.hasFnAttribute(Attribute::SanitizeAddress)) return FunctionModified;

LLVM_DEBUG(dbgs() << "ASAN instrumenting:\n" << F << "\n")do { } while (false);

initializeCallbacks(*F.getParent());

FunctionStateRAII CleanupObj(this);

FunctionModified |= maybeInsertDynamicShadowAtFunctionEntry(F);

// We can't instrument allocas used with llvm.localescape. Only static allocas
// can be passed to that intrinsic.
markEscapedLocalAllocas(F);

// We want to instrument every address only once per basic block (unless there
// are calls between uses).
SmallPtrSet<Value *, 16> TempsToInstrument;
SmallVector<InterestingMemoryOperand, 16> OperandsToInstrument;
SmallVector<MemIntrinsic *, 16> IntrinToInstrument;
SmallVector<Instruction *, 8> NoReturnCalls;
SmallVector<BasicBlock *, 16> AllBlocks;
SmallVector<Instruction *, 16> PointerComparisonsOrSubtracts;
int NumAllocas = 0;

// Fill the set of memory operations to instrument.
for (auto &BB : F) {
  AllBlocks.push_back(&BB);
  TempsToInstrument.clear();
  int NumInsnsPerBB = 0;
  for (auto &Inst : BB) {
    if (LooksLikeCodeInBug11395(&Inst)) return false;
    SmallVector<InterestingMemoryOperand, 1> InterestingOperands;
    getInterestingMemoryOperands(&Inst, InterestingOperands);

    if (!InterestingOperands.empty()) {
      for (auto &Operand : InterestingOperands) {
        if (ClOpt && ClOptSameTemp) {
          Value *Ptr = Operand.getPtr();
          // If we have a mask, skip instrumentation if we've already
          // instrumented the full object. But don't add to TempsToInstrument
          // because we might get another load/store with a different mask.
          if (Operand.MaybeMask) {
            if (TempsToInstrument.count(Ptr))
              continue; // We've seen this (whole) temp in the current BB.
          } else {
            if (!TempsToInstrument.insert(Ptr).second)
              continue; // We've seen this temp in the current BB.
          }
        }
        OperandsToInstrument.push_back(Operand);
        NumInsnsPerBB++;
      }
    } else if (((ClInvalidPointerPairs || ClInvalidPointerCmp) &&
                isInterestingPointerComparison(&Inst)) ||
               ((ClInvalidPointerPairs || ClInvalidPointerSub) &&
                isInterestingPointerSubtraction(&Inst))) {
      PointerComparisonsOrSubtracts.push_back(&Inst);
    } else if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(&Inst)) {
      // ok, take it.
      IntrinToInstrument.push_back(MI);
      NumInsnsPerBB++;
    } else {
      if (isa<AllocaInst>(Inst)) NumAllocas++;
      if (auto *CB = dyn_cast<CallBase>(&Inst)) {
        // A call inside BB.
        TempsToInstrument.clear();
        if (CB->doesNotReturn() && !CB->hasMetadata("nosanitize"))
          NoReturnCalls.push_back(CB);
      }
      if (CallInst *CI = dyn_cast<CallInst>(&Inst))
        maybeMarkSanitizerLibraryCallNoBuiltin(CI, TLI);
    }
    if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB) break;
  }
}

bool UseCalls = (ClInstrumentationWithCallsThreshold >= 0 &&
                 OperandsToInstrument.size() + IntrinToInstrument.size() >
                     (unsigned)ClInstrumentationWithCallsThreshold);
const DataLayout &DL = F.getParent()->getDataLayout();
ObjectSizeOpts ObjSizeOpts;
ObjSizeOpts.RoundToAlign = true;
ObjectSizeOffsetVisitor ObjSizeVis(DL, TLI, F.getContext(), ObjSizeOpts);

// Instrument.
int NumInstrumented = 0;
for (auto &Operand : OperandsToInstrument) {
  if (!suppressInstrumentationSiteForDebug(NumInstrumented))
    instrumentMop(ObjSizeVis, Operand, UseCalls,
                  F.getParent()->getDataLayout());
  FunctionModified = true;
}
for (auto Inst : IntrinToInstrument) {
  if (!suppressInstrumentationSiteForDebug(NumInstrumented))
    instrumentMemIntrinsic(Inst);
  FunctionModified = true;
}

FunctionStackPoisoner FSP(F, *this);
bool ChangedStack = FSP.runOnFunction();

// We must unpoison the stack before NoReturn calls (throw, _exit, etc).
// See e.g. https://github.com/google/sanitizers/issues/37
for (auto CI : NoReturnCalls) {
  IRBuilder<> IRB(CI);
  IRB.CreateCall(AsanHandleNoReturnFunc, {});
}

for (auto Inst : PointerComparisonsOrSubtracts) {
  instrumentPointerComparisonOrSubtraction(Inst);
  FunctionModified = true;
}

if (ChangedStack || !NoReturnCalls.empty())
  FunctionModified = true;

LLVM_DEBUG(dbgs() << "ASAN done instrumenting: " << FunctionModified << " "do { } while (false)
                  << F << "\n")do { } while (false);

return FunctionModified;
2956}

2958// Workaround for bug 11395: we don't want to instrument stack in functions
2959// with large assembly blobs (32-bit only), otherwise reg alloc may crash.
2960// FIXME: remove once the bug 11395 is fixed.
2961bool AddressSanitizer::LooksLikeCodeInBug11395(Instruction *I) {
if (LongSize != 32) return false;
CallInst *CI = dyn_cast<CallInst>(I);
if (!CI || !CI->isInlineAsm()) return false;
if (CI->getNumArgOperands() <= 5) return false;
// We have inline assembly with quite a few arguments.
return true;
2968}

2970void FunctionStackPoisoner::initializeCallbacks(Module &M) {
IRBuilder<> IRB(*C);
if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always ||
    ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
  const char *MallocNameTemplate =
      ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Always
          ? kAsanStackMallocAlwaysNameTemplate
          : kAsanStackMallocNameTemplate;
  for (int Index = 0; Index <= kMaxAsanStackMallocSizeClass; Index++) {
    std::string Suffix = itostr(Index);
    AsanStackMallocFunc[Index] = M.getOrInsertFunction(
        MallocNameTemplate + Suffix, IntptrTy, IntptrTy);
    AsanStackFreeFunc[Index] =
        M.getOrInsertFunction(kAsanStackFreeNameTemplate + Suffix,
                              IRB.getVoidTy(), IntptrTy, IntptrTy);
  }
}
if (ASan.UseAfterScope) {
  AsanPoisonStackMemoryFunc = M.getOrInsertFunction(
      kAsanPoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
  AsanUnpoisonStackMemoryFunc = M.getOrInsertFunction(
      kAsanUnpoisonStackMemoryName, IRB.getVoidTy(), IntptrTy, IntptrTy);
}

for (size_t Val : {0x00, 0xf1, 0xf2, 0xf3, 0xf5, 0xf8}) {
  std::ostringstream Name;
  Name << kAsanSetShadowPrefix;
  Name << std::setw(2) << std::setfill('0') << std::hex << Val;
  AsanSetShadowFunc[Val] =
      M.getOrInsertFunction(Name.str(), IRB.getVoidTy(), IntptrTy, IntptrTy);
}

AsanAllocaPoisonFunc = M.getOrInsertFunction(
    kAsanAllocaPoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
AsanAllocasUnpoisonFunc = M.getOrInsertFunction(
    kAsanAllocasUnpoison, IRB.getVoidTy(), IntptrTy, IntptrTy);
3006}

3008void FunctionStackPoisoner::copyToShadowInline(ArrayRef<uint8_t> ShadowMask,
                                             ArrayRef<uint8_t> ShadowBytes,
                                             size_t Begin, size_t End,
                                             IRBuilder<> &IRB,
                                             Value *ShadowBase) {
if (Begin >= End)
  return;

const size_t LargestStoreSizeInBytes =
    std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);

const bool IsLittleEndian = F.getParent()->getDataLayout().isLittleEndian();

// Poison given range in shadow using larges store size with out leading and
// trailing zeros in ShadowMask. Zeros never change, so they need neither
// poisoning nor up-poisoning. Still we don't mind if some of them get into a
// middle of a store.
for (size_t i = Begin; i < End;) {
  if (!ShadowMask[i]) {
    assert(!ShadowBytes[i])(static_cast<void> (0));
    ++i;
    continue;
  }

  size_t StoreSizeInBytes = LargestStoreSizeInBytes;
  // Fit store size into the range.
  while (StoreSizeInBytes > End - i)
    StoreSizeInBytes /= 2;

  // Minimize store size by trimming trailing zeros.
  for (size_t j = StoreSizeInBytes - 1; j && !ShadowMask[i + j]; --j) {
    while (j <= StoreSizeInBytes / 2)
      StoreSizeInBytes /= 2;
  }

  uint64_t Val = 0;
  for (size_t j = 0; j < StoreSizeInBytes; j++) {
    if (IsLittleEndian)
      Val |= (uint64_t)ShadowBytes[i + j] << (8 * j);
    else
      Val = (Val << 8) | ShadowBytes[i + j];
  }

  Value *Ptr = IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i));
  Value *Poison = IRB.getIntN(StoreSizeInBytes * 8, Val);
  IRB.CreateAlignedStore(
      Poison, IRB.CreateIntToPtr(Ptr, Poison->getType()->getPointerTo()),
      Align(1));

  i += StoreSizeInBytes;
}
3059}

3061void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
                                       ArrayRef<uint8_t> ShadowBytes,
                                       IRBuilder<> &IRB, Value *ShadowBase) {
copyToShadow(ShadowMask, ShadowBytes, 0, ShadowMask.size(), IRB, ShadowBase);
3065}

3067void FunctionStackPoisoner::copyToShadow(ArrayRef<uint8_t> ShadowMask,
                                       ArrayRef<uint8_t> ShadowBytes,
                                       size_t Begin, size_t End,
                                       IRBuilder<> &IRB, Value *ShadowBase) {
assert(ShadowMask.size() == ShadowBytes.size())(static_cast<void> (0));
size_t Done = Begin;
for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
  if (!ShadowMask[i]) {
    assert(!ShadowBytes[i])(static_cast<void> (0));
    continue;
  }
  uint8_t Val = ShadowBytes[i];
  if (!AsanSetShadowFunc[Val])
    continue;

  // Skip same values.
  for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
  }

  if (j - i >= ClMaxInlinePoisoningSize) {
    copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
    IRB.CreateCall(AsanSetShadowFunc[Val],
                   {IRB.CreateAdd(ShadowBase, ConstantInt::get(IntptrTy, i)),
                    ConstantInt::get(IntptrTy, j - i)});
    Done = j;
  }
}

copyToShadowInline(ShadowMask, ShadowBytes, Done, End, IRB, ShadowBase);
3096}

3098// Fake stack allocator (asan_fake_stack.h) has 11 size classes
3099// for every power of 2 from kMinStackMallocSize to kMaxAsanStackMallocSizeClass
3100static int StackMallocSizeClass(uint64_t LocalStackSize) {
assert(LocalStackSize <= kMaxStackMallocSize)(static_cast<void> (0));
uint64_t MaxSize = kMinStackMallocSize;
for (int i = 0;; i++, MaxSize *= 2)
  if (LocalStackSize <= MaxSize) return i;
llvm_unreachable("impossible LocalStackSize")__builtin_unreachable();
3106}

3108void FunctionStackPoisoner::copyArgsPassedByValToAllocas() {
Instruction *CopyInsertPoint = &F.front().front();
if (CopyInsertPoint == ASan.LocalDynamicShadow) {
  // Insert after the dynamic shadow location is determined
  CopyInsertPoint = CopyInsertPoint->getNextNode();
  assert(CopyInsertPoint)(static_cast<void> (0));
}
IRBuilder<> IRB(CopyInsertPoint);
const DataLayout &DL = F.getParent()->getDataLayout();
for (Argument &Arg : F.args()) {
  if (Arg.hasByValAttr()) {
    Type *Ty = Arg.getParamByValType();
    const Align Alignment =
        DL.getValueOrABITypeAlignment(Arg.getParamAlign(), Ty);

    AllocaInst *AI = IRB.CreateAlloca(
        Ty, nullptr,
        (Arg.hasName() ? Arg.getName() : "Arg" + Twine(Arg.getArgNo())) +
            ".byval");
    AI->setAlignment(Alignment);
    Arg.replaceAllUsesWith(AI);

    uint64_t AllocSize = DL.getTypeAllocSize(Ty);
    IRB.CreateMemCpy(AI, Alignment, &Arg, Alignment, AllocSize);
  }
}
3134}

3136PHINode *FunctionStackPoisoner::createPHI(IRBuilder<> &IRB, Value *Cond,
                                        Value *ValueIfTrue,
                                        Instruction *ThenTerm,
                                        Value *ValueIfFalse) {
PHINode *PHI = IRB.CreatePHI(IntptrTy, 2);
BasicBlock *CondBlock = cast<Instruction>(Cond)->getParent();
PHI->addIncoming(ValueIfFalse, CondBlock);
BasicBlock *ThenBlock = ThenTerm->getParent();
PHI->addIncoming(ValueIfTrue, ThenBlock);
return PHI;
3146}

3148Value *FunctionStackPoisoner::createAllocaForLayout(
  IRBuilder<> &IRB, const ASanStackFrameLayout &L, bool Dynamic) {
AllocaInst *Alloca;
if (Dynamic) {
  Alloca = IRB.CreateAlloca(IRB.getInt8Ty(),
                            ConstantInt::get(IRB.getInt64Ty(), L.FrameSize),
                            "MyAlloca");
} else {
  Alloca = IRB.CreateAlloca(ArrayType::get(IRB.getInt8Ty(), L.FrameSize),
                            nullptr, "MyAlloca");
  assert(Alloca->isStaticAlloca())(static_cast<void> (0));
}
assert((ClRealignStack & (ClRealignStack - 1)) == 0)(static_cast<void> (0));
size_t FrameAlignment = std::max(L.FrameAlignment, (size_t)ClRealignStack);
Alloca->setAlignment(Align(FrameAlignment));
return IRB.CreatePointerCast(Alloca, IntptrTy);
3164}

3166void FunctionStackPoisoner::createDynamicAllocasInitStorage() {
BasicBlock &FirstBB = *F.begin();
IRBuilder<> IRB(dyn_cast<Instruction>(FirstBB.begin()));
DynamicAllocaLayout = IRB.CreateAlloca(IntptrTy, nullptr);
IRB.CreateStore(Constant::getNullValue(IntptrTy), DynamicAllocaLayout);
DynamicAllocaLayout->setAlignment(Align(32));
3172}

3174void FunctionStackPoisoner::processDynamicAllocas() {
if (!ClInstrumentDynamicAllocas || DynamicAllocaVec.empty()) {
  assert(DynamicAllocaPoisonCallVec.empty())(static_cast<void> (0));
  return;
}

// Insert poison calls for lifetime intrinsics for dynamic allocas.
for (const auto &APC : DynamicAllocaPoisonCallVec) {
  assert(APC.InsBefore)(static_cast<void> (0));
  assert(APC.AI)(static_cast<void> (0));
  assert(ASan.isInterestingAlloca(*APC.AI))(static_cast<void> (0));
  assert(!APC.AI->isStaticAlloca())(static_cast<void> (0));

  IRBuilder<> IRB(APC.InsBefore);
  poisonAlloca(APC.AI, APC.Size, IRB, APC.DoPoison);
  // Dynamic allocas will be unpoisoned unconditionally below in
  // unpoisonDynamicAllocas.
  // Flag that we need unpoison static allocas.
}

// Handle dynamic allocas.
createDynamicAllocasInitStorage();
for (auto &AI : DynamicAllocaVec)
  handleDynamicAllocaCall(AI);
unpoisonDynamicAllocas();
3199}

3201/// Collect instructions in the entry block after \p InsBefore which initialize
3202/// permanent storage for a function argument. These instructions must remain in
3203/// the entry block so that uninitialized values do not appear in backtraces. An
3204/// added benefit is that this conserves spill slots. This does not move stores
3205/// before instrumented / "interesting" allocas.
3206static void findStoresToUninstrumentedArgAllocas(
  AddressSanitizer &ASan, Instruction &InsBefore,
  SmallVectorImpl<Instruction *> &InitInsts) {
Instruction *Start = InsBefore.getNextNonDebugInstruction();
for (Instruction *It = Start; It; It = It->getNextNonDebugInstruction()) {
  // Argument initialization looks like:
  // 1) store <Argument>, <Alloca> OR
  // 2) <CastArgument> = cast <Argument> to ...
  //    store <CastArgument> to <Alloca>
  // Do not consider any other kind of instruction.
  //
  // Note: This covers all known cases, but may not be exhaustive. An
  // alternative to pattern-matching stores is to DFS over all Argument uses:
  // this might be more general, but is probably much more complicated.
  if (isa<AllocaInst>(It) || isa<CastInst>(It))
    continue;
  if (auto *Store = dyn_cast<StoreInst>(It)) {
    // The store destination must be an alloca that isn't interesting for
    // ASan to instrument. These are moved up before InsBefore, and they're
    // not interesting because allocas for arguments can be mem2reg'd.
    auto *Alloca = dyn_cast<AllocaInst>(Store->getPointerOperand());
    if (!Alloca || ASan.isInterestingAlloca(*Alloca))
      continue;

    Value *Val = Store->getValueOperand();
    bool IsDirectArgInit = isa<Argument>(Val);
    bool IsArgInitViaCast =
        isa<CastInst>(Val) &&
        isa<Argument>(cast<CastInst>(Val)->getOperand(0)) &&
        // Check that the cast appears directly before the store. Otherwise
        // moving the cast before InsBefore may break the IR.
        Val == It->getPrevNonDebugInstruction();
    bool IsArgInit = IsDirectArgInit || IsArgInitViaCast;
    if (!IsArgInit)
      continue;

    if (IsArgInitViaCast)
      InitInsts.push_back(cast<Instruction>(Val));
    InitInsts.push_back(Store);
    continue;
  }

  // Do not reorder past unknown instructions: argument initialization should
  // only involve casts and stores.
  return;
}
3252}

3254void FunctionStackPoisoner::processStaticAllocas() {
if (AllocaVec.empty()) {
  assert(StaticAllocaPoisonCallVec.empty())(static_cast<void> (0));
  return;
}

int StackMallocIdx = -1;
DebugLoc EntryDebugLocation;
if (auto SP = F.getSubprogram())
  EntryDebugLocation =
      DILocation::get(SP->getContext(), SP->getScopeLine(), 0, SP);

Instruction *InsBefore = AllocaVec[0];
IRBuilder<> IRB(InsBefore);

// Make sure non-instrumented allocas stay in the entry block. Otherwise,
// debug info is broken, because only entry-block allocas are treated as
// regular stack slots.
auto InsBeforeB = InsBefore->getParent();
assert(InsBeforeB == &F.getEntryBlock())(static_cast<void> (0));
for (auto *AI : StaticAllocasToMoveUp)
  if (AI->getParent() == InsBeforeB)
    AI->moveBefore(InsBefore);

// Move stores of arguments into entry-block allocas as well. This prevents
// extra stack slots from being generated (to house the argument values until
// they can be stored into the allocas). This also prevents uninitialized
// values from being shown in backtraces.
SmallVector<Instruction *, 8> ArgInitInsts;
findStoresToUninstrumentedArgAllocas(ASan, *InsBefore, ArgInitInsts);
for (Instruction *ArgInitInst : ArgInitInsts)
  ArgInitInst->moveBefore(InsBefore);

// If we have a call to llvm.localescape, keep it in the entry block.
if (LocalEscapeCall) LocalEscapeCall->moveBefore(InsBefore);

SmallVector<ASanStackVariableDescription, 16> SVD;
SVD.reserve(AllocaVec.size());
for (AllocaInst *AI : AllocaVec) {
  ASanStackVariableDescription D = {AI->getName().data(),
                                    ASan.getAllocaSizeInBytes(*AI),
                                    0,
                                    AI->getAlignment(),
                                    AI,
                                    0,
                                    0};
  SVD.push_back(D);
}

// Minimal header size (left redzone) is 4 pointers,
// i.e. 32 bytes on 64-bit platforms and 16 bytes in 32-bit platforms.
size_t Granularity = 1ULL << Mapping.Scale;
size_t MinHeaderSize = std::max((size_t)ASan.LongSize / 2, Granularity);
const ASanStackFrameLayout &L =
    ComputeASanStackFrameLayout(SVD, Granularity, MinHeaderSize);

// Build AllocaToSVDMap for ASanStackVariableDescription lookup.
DenseMap<const AllocaInst *, ASanStackVariableDescription *> AllocaToSVDMap;
for (auto &Desc : SVD)
  AllocaToSVDMap[Desc.AI] = &Desc;

// Update SVD with information from lifetime intrinsics.
for (const auto &APC : StaticAllocaPoisonCallVec) {
  assert(APC.InsBefore)(static_cast<void> (0));
  assert(APC.AI)(static_cast<void> (0));
  assert(ASan.isInterestingAlloca(*APC.AI))(static_cast<void> (0));
  assert(APC.AI->isStaticAlloca())(static_cast<void> (0));

  ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
  Desc.LifetimeSize = Desc.Size;
  if (const DILocation *FnLoc = EntryDebugLocation.get()) {
    if (const DILocation *LifetimeLoc = APC.InsBefore->getDebugLoc().get()) {
      if (LifetimeLoc->getFile() == FnLoc->getFile())
        if (unsigned Line = LifetimeLoc->getLine())
          Desc.Line = std::min(Desc.Line ? Desc.Line : Line, Line);
    }
  }
}

auto DescriptionString = ComputeASanStackFrameDescription(SVD);
LLVM_DEBUG(dbgs() << DescriptionString << " --- " << L.FrameSize << "\n")do { } while (false);
uint64_t LocalStackSize = L.FrameSize;
bool DoStackMalloc =
    ASan.UseAfterReturn != AsanDetectStackUseAfterReturnMode::Never &&
    !ASan.CompileKernel && LocalStackSize <= kMaxStackMallocSize;
bool DoDynamicAlloca = ClDynamicAllocaStack;
// Don't do dynamic alloca or stack malloc if:
// 1) There is inline asm: too often it makes assumptions on which registers
//    are available.
// 2) There is a returns_twice call (typically setjmp), which is
//    optimization-hostile, and doesn't play well with introduced indirect
//    register-relative calculation of local variable addresses.
DoDynamicAlloca &= !HasInlineAsm && !HasReturnsTwiceCall;
DoStackMalloc &= !HasInlineAsm && !HasReturnsTwiceCall;

Value *StaticAlloca =
    DoDynamicAlloca ? nullptr : createAllocaForLayout(IRB, L, false);

Value *FakeStack;
Value *LocalStackBase;
Value *LocalStackBaseAlloca;
uint8_t DIExprFlags = DIExpression::ApplyOffset;

if (DoStackMalloc) {
  LocalStackBaseAlloca =
      IRB.CreateAlloca(IntptrTy, nullptr, "asan_local_stack_base");
  if (ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode::Runtime) {
    // void *FakeStack = __asan_option_detect_stack_use_after_return
    //     ? __asan_stack_malloc_N(LocalStackSize)
    //     : nullptr;
    // void *LocalStackBase = (FakeStack) ? FakeStack :
    //                        alloca(LocalStackSize);
    Constant *OptionDetectUseAfterReturn = F.getParent()->getOrInsertGlobal(
        kAsanOptionDetectUseAfterReturn, IRB.getInt32Ty());
    Value *UseAfterReturnIsEnabled = IRB.CreateICmpNE(
        IRB.CreateLoad(IRB.getInt32Ty(), OptionDetectUseAfterReturn),
        Constant::getNullValue(IRB.getInt32Ty()));
    Instruction *Term =
        SplitBlockAndInsertIfThen(UseAfterReturnIsEnabled, InsBefore, false);
    IRBuilder<> IRBIf(Term);
    StackMallocIdx = StackMallocSizeClass(LocalStackSize);
    assert(StackMallocIdx <= kMaxAsanStackMallocSizeClass)(static_cast<void> (0));
    Value *FakeStackValue =
        IRBIf.CreateCall(AsanStackMallocFunc[StackMallocIdx],
                         ConstantInt::get(IntptrTy, LocalStackSize));
    IRB.SetInsertPoint(InsBefore);
    FakeStack = createPHI(IRB, UseAfterReturnIsEnabled, FakeStackValue, Term,
                          ConstantInt::get(IntptrTy, 0));
  } else {
    // assert(ASan.UseAfterReturn == AsanDetectStackUseAfterReturnMode:Always)
    // void *FakeStack = __asan_stack_malloc_N(LocalStackSize);
    // void *LocalStackBase = (FakeStack) ? FakeStack :
    //                        alloca(LocalStackSize);
    StackMallocIdx = StackMallocSizeClass(LocalStackSize);
    FakeStack = IRB.CreateCall(AsanStackMallocFunc[StackMallocIdx],
                               ConstantInt::get(IntptrTy, LocalStackSize));
  }
  Value *NoFakeStack =
      IRB.CreateICmpEQ(FakeStack, Constant::getNullValue(IntptrTy));
  Instruction *Term =
      SplitBlockAndInsertIfThen(NoFakeStack, InsBefore, false);
  IRBuilder<> IRBIf(Term);
  Value *AllocaValue =
      DoDynamicAlloca ? createAllocaForLayout(IRBIf, L, true) : StaticAlloca;

  IRB.SetInsertPoint(InsBefore);
  LocalStackBase = createPHI(IRB, NoFakeStack, AllocaValue, Term, FakeStack);
  IRB.CreateStore(LocalStackBase, LocalStackBaseAlloca);
  DIExprFlags |= DIExpression::DerefBefore;
} else {
  // void *FakeStack = nullptr;
  // void *LocalStackBase = alloca(LocalStackSize);
  FakeStack = ConstantInt::get(IntptrTy, 0);
  LocalStackBase =
      DoDynamicAlloca ? createAllocaForLayout(IRB, L, true) : StaticAlloca;
  LocalStackBaseAlloca = LocalStackBase;
}

// It shouldn't matter whether we pass an `alloca` or a `ptrtoint` as the
// dbg.declare address opereand, but passing a `ptrtoint` seems to confuse
// later passes and can result in dropped variable coverage in debug info.
Value *LocalStackBaseAllocaPtr =
    isa<PtrToIntInst>(LocalStackBaseAlloca)
        ? cast<PtrToIntInst>(LocalStackBaseAlloca)->getPointerOperand()
        : LocalStackBaseAlloca;
assert(isa<AllocaInst>(LocalStackBaseAllocaPtr) &&(static_cast<void> (0))
       "Variable descriptions relative to ASan stack base will be dropped")(static_cast<void> (0));

// Replace Alloca instructions with base+offset.
for (const auto &Desc : SVD) {
  AllocaInst *AI = Desc.AI;
  replaceDbgDeclare(AI, LocalStackBaseAllocaPtr, DIB, DIExprFlags,
                    Desc.Offset);
  Value *NewAllocaPtr = IRB.CreateIntToPtr(
      IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Desc.Offset)),
      AI->getType());
  AI->replaceAllUsesWith(NewAllocaPtr);
}

// The left-most redzone has enough space for at least 4 pointers.
// Write the Magic value to redzone[0].
Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
IRB.CreateStore(ConstantInt::get(IntptrTy, kCurrentStackFrameMagic),
                BasePlus0);
// Write the frame description constant to redzone[1].
Value *BasePlus1 = IRB.CreateIntToPtr(
    IRB.CreateAdd(LocalStackBase,
                  ConstantInt::get(IntptrTy, ASan.LongSize / 8)),
    IntptrPtrTy);
GlobalVariable *StackDescriptionGlobal =
    createPrivateGlobalForString(*F.getParent(), DescriptionString,
                                 /*AllowMerging*/ true, kAsanGenPrefix);
Value *Description = IRB.CreatePointerCast(StackDescriptionGlobal, IntptrTy);
IRB.CreateStore(Description, BasePlus1);
// Write the PC to redzone[2].
Value *BasePlus2 = IRB.CreateIntToPtr(
    IRB.CreateAdd(LocalStackBase,
                  ConstantInt::get(IntptrTy, 2 * ASan.LongSize / 8)),
    IntptrPtrTy);
IRB.CreateStore(IRB.CreatePointerCast(&F, IntptrTy), BasePlus2);

const auto &ShadowAfterScope = GetShadowBytesAfterScope(SVD, L);

// Poison the stack red zones at the entry.
Value *ShadowBase = ASan.memToShadow(LocalStackBase, IRB);
// As mask we must use most poisoned case: red zones and after scope.
// As bytes we can use either the same or just red zones only.
copyToShadow(ShadowAfterScope, ShadowAfterScope, IRB, ShadowBase);

if (!StaticAllocaPoisonCallVec.empty()) {
  const auto &ShadowInScope = GetShadowBytes(SVD, L);

  // Poison static allocas near lifetime intrinsics.
  for (const auto &APC : StaticAllocaPoisonCallVec) {
    const ASanStackVariableDescription &Desc = *AllocaToSVDMap[APC.AI];
    assert(Desc.Offset % L.Granularity == 0)(static_cast<void> (0));
    size_t Begin = Desc.Offset / L.Granularity;
    size_t End = Begin + (APC.Size + L.Granularity - 1) / L.Granularity;

    IRBuilder<> IRB(APC.InsBefore);
    copyToShadow(ShadowAfterScope,
                 APC.DoPoison ? ShadowAfterScope : ShadowInScope, Begin, End,
                 IRB, ShadowBase);
  }
}

SmallVector<uint8_t, 64> ShadowClean(ShadowAfterScope.size(), 0);
SmallVector<uint8_t, 64> ShadowAfterReturn;

// (Un)poison the stack before all ret instructions.
for (Instruction *Ret : RetVec) {
  IRBuilder<> IRBRet(Ret);
  // Mark the current frame as retired.
  IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
                     BasePlus0);
  if (DoStackMalloc) {
    assert(StackMallocIdx >= 0)(static_cast<void> (0));
    // if FakeStack != 0  // LocalStackBase == FakeStack
    //     // In use-after-return mode, poison the whole stack frame.
    //     if StackMallocIdx <= 4
    //         // For small sizes inline the whole thing:
    //         memset(ShadowBase, kAsanStackAfterReturnMagic, ShadowSize);
    //         **SavedFlagPtr(FakeStack) = 0
    //     else
    //         __asan_stack_free_N(FakeStack, LocalStackSize)
    // else
    //     <This is not a fake stack; unpoison the redzones>
    Value *Cmp =
        IRBRet.CreateICmpNE(FakeStack, Constant::getNullValue(IntptrTy));
    Instruction *ThenTerm, *ElseTerm;
    SplitBlockAndInsertIfThenElse(Cmp, Ret, &ThenTerm, &ElseTerm);

    IRBuilder<> IRBPoison(ThenTerm);
    if (StackMallocIdx <= 4) {
      int ClassSize = kMinStackMallocSize << StackMallocIdx;
      ShadowAfterReturn.resize(ClassSize / L.Granularity,
                               kAsanStackUseAfterReturnMagic);
      copyToShadow(ShadowAfterReturn, ShadowAfterReturn, IRBPoison,
                   ShadowBase);
      Value *SavedFlagPtrPtr = IRBPoison.CreateAdd(
          FakeStack,
          ConstantInt::get(IntptrTy, ClassSize - ASan.LongSize / 8));
      Value *SavedFlagPtr = IRBPoison.CreateLoad(
          IntptrTy, IRBPoison.CreateIntToPtr(SavedFlagPtrPtr, IntptrPtrTy));
      IRBPoison.CreateStore(
          Constant::getNullValue(IRBPoison.getInt8Ty()),
          IRBPoison.CreateIntToPtr(SavedFlagPtr, IRBPoison.getInt8PtrTy()));
    } else {
      // For larger frames call __asan_stack_free_*.
      IRBPoison.CreateCall(
          AsanStackFreeFunc[StackMallocIdx],
          {FakeStack, ConstantInt::get(IntptrTy, LocalStackSize)});
    }

    IRBuilder<> IRBElse(ElseTerm);
    copyToShadow(ShadowAfterScope, ShadowClean, IRBElse, ShadowBase);
  } else {
    copyToShadow(ShadowAfterScope, ShadowClean, IRBRet, ShadowBase);
  }
}

// We are done. Remove the old unused alloca instructions.
for (auto AI : AllocaVec) AI->eraseFromParent();
3537}

3539void FunctionStackPoisoner::poisonAlloca(Value *V, uint64_t Size,
                                       IRBuilder<> &IRB, bool DoPoison) {
// For now just insert the call to ASan runtime.
Value *AddrArg = IRB.CreatePointerCast(V, IntptrTy);
Value *SizeArg = ConstantInt::get(IntptrTy, Size);
IRB.CreateCall(
    DoPoison ? AsanPoisonStackMemoryFunc : AsanUnpoisonStackMemoryFunc,
    {AddrArg, SizeArg});
3547}

3549// Handling llvm.lifetime intrinsics for a given %alloca:
3550// (1) collect all llvm.lifetime.xxx(%size, %value) describing the alloca.
3551// (2) if %size is constant, poison memory for llvm.lifetime.end (to detect
3552//     invalid accesses) and unpoison it for llvm.lifetime.start (the memory
3553//     could be poisoned by previous llvm.lifetime.end instruction, as the
3554//     variable may go in and out of scope several times, e.g. in loops).
3555// (3) if we poisoned at least one %alloca in a function,
3556//     unpoison the whole stack frame at function exit.
3557void FunctionStackPoisoner::handleDynamicAllocaCall(AllocaInst *AI) {
IRBuilder<> IRB(AI);

const unsigned Alignment = std::max(kAllocaRzSize, AI->getAlignment());
const uint64_t AllocaRedzoneMask = kAllocaRzSize - 1;

Value *Zero = Constant::getNullValue(IntptrTy);
Value *AllocaRzSize = ConstantInt::get(IntptrTy, kAllocaRzSize);
Value *AllocaRzMask = ConstantInt::get(IntptrTy, AllocaRedzoneMask);

// Since we need to extend alloca with additional memory to locate
// redzones, and OldSize is number of allocated blocks with
// ElementSize size, get allocated memory size in bytes by
// OldSize * ElementSize.
const unsigned ElementSize =
    F.getParent()->getDataLayout().getTypeAllocSize(AI->getAllocatedType());
Value *OldSize =
    IRB.CreateMul(IRB.CreateIntCast(AI->getArraySize(), IntptrTy, false),
                  ConstantInt::get(IntptrTy, ElementSize));

// PartialSize = OldSize % 32
Value *PartialSize = IRB.CreateAnd(OldSize, AllocaRzMask);

// Misalign = kAllocaRzSize - PartialSize;
Value *Misalign = IRB.CreateSub(AllocaRzSize, PartialSize);

// PartialPadding = Misalign != kAllocaRzSize ? Misalign : 0;
Value *Cond = IRB.CreateICmpNE(Misalign, AllocaRzSize);
Value *PartialPadding = IRB.CreateSelect(Cond, Misalign, Zero);

// AdditionalChunkSize = Alignment + PartialPadding + kAllocaRzSize
// Alignment is added to locate left redzone, PartialPadding for possible
// partial redzone and kAllocaRzSize for right redzone respectively.
Value *AdditionalChunkSize = IRB.CreateAdd(
    ConstantInt::get(IntptrTy, Alignment + kAllocaRzSize), PartialPadding);

Value *NewSize = IRB.CreateAdd(OldSize, AdditionalChunkSize);

// Insert new alloca with new NewSize and Alignment params.
AllocaInst *NewAlloca = IRB.CreateAlloca(IRB.getInt8Ty(), NewSize);
NewAlloca->setAlignment(Align(Alignment));

// NewAddress = Address + Alignment
Value *NewAddress = IRB.CreateAdd(IRB.CreatePtrToInt(NewAlloca, IntptrTy),
                                  ConstantInt::get(IntptrTy, Alignment));

// Insert __asan_alloca_poison call for new created alloca.
IRB.CreateCall(AsanAllocaPoisonFunc, {NewAddress, OldSize});

// Store the last alloca's address to DynamicAllocaLayout. We'll need this
// for unpoisoning stuff.
IRB.CreateStore(IRB.CreatePtrToInt(NewAlloca, IntptrTy), DynamicAllocaLayout);

Value *NewAddressPtr = IRB.CreateIntToPtr(NewAddress, AI->getType());

// Replace all uses of AddessReturnedByAlloca with NewAddressPtr.
AI->replaceAllUsesWith(NewAddressPtr);

// We are done. Erase old alloca from parent.
AI->eraseFromParent();
3617}

3619// isSafeAccess returns true if Addr is always inbounds with respect to its
3620// base object. For example, it is a field access or an array access with
3621// constant inbounds index.
3622bool AddressSanitizer::isSafeAccess(ObjectSizeOffsetVisitor &ObjSizeVis,
                                  Value *Addr, uint64_t TypeSize) const {
SizeOffsetType SizeOffset = ObjSizeVis.compute(Addr);
if (!ObjSizeVis.bothKnown(SizeOffset)) return false;
uint64_t Size = SizeOffset.first.getZExtValue();
int64_t Offset = SizeOffset.second.getSExtValue();
// Three checks are required to ensure safety:
// . Offset >= 0  (since the offset is given from the base ptr)
// . Size >= Offset  (unsigned)
// . Size - Offset >= NeededSize  (unsigned)
return Offset >= 0 && Size >= uint64_t(Offset) &&
       Size - uint64_t(Offset) >= TypeSize / 8;
3634}