mirror of
https://github.com/c64scene-ar/llvm-6502.git
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162566 91177308-0d34-0410-b5e6-96231b3b80d8
1163 lines
45 KiB
C++
1163 lines
45 KiB
C++
//===-- AddressSanitizer.cpp - memory error detector ------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of AddressSanitizer, an address sanity checker.
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// Details of the algorithm:
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// http://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm
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//
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//===----------------------------------------------------------------------===//
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#define DEBUG_TYPE "asan"
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#include "BlackList.h"
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#include "llvm/Function.h"
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#include "llvm/IRBuilder.h"
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#include "llvm/InlineAsm.h"
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#include "llvm/IntrinsicInst.h"
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#include "llvm/LLVMContext.h"
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#include "llvm/Module.h"
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#include "llvm/Type.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/OwningPtr.h"
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#include "llvm/ADT/SmallSet.h"
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#include "llvm/ADT/SmallString.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/ADT/StringExtras.h"
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#include "llvm/ADT/Triple.h"
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#include "llvm/Support/CommandLine.h"
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#include "llvm/Support/DataTypes.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Support/system_error.h"
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#include "llvm/Target/TargetData.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Transforms/Instrumentation.h"
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#include "llvm/Transforms/Utils/BasicBlockUtils.h"
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#include "llvm/Transforms/Utils/ModuleUtils.h"
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#include <string>
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#include <algorithm>
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using namespace llvm;
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static const uint64_t kDefaultShadowScale = 3;
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static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
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static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
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static const uint64_t kDefaultShadowOffsetAndroid = 0;
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static const size_t kMaxStackMallocSize = 1 << 16; // 64K
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static const uintptr_t kCurrentStackFrameMagic = 0x41B58AB3;
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static const uintptr_t kRetiredStackFrameMagic = 0x45E0360E;
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static const char *kAsanModuleCtorName = "asan.module_ctor";
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static const char *kAsanModuleDtorName = "asan.module_dtor";
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static const int kAsanCtorAndCtorPriority = 1;
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static const char *kAsanReportErrorTemplate = "__asan_report_";
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static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
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static const char *kAsanUnregisterGlobalsName = "__asan_unregister_globals";
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static const char *kAsanPoisonGlobalsName = "__asan_before_dynamic_init";
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static const char *kAsanUnpoisonGlobalsName = "__asan_after_dynamic_init";
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static const char *kAsanInitName = "__asan_init";
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static const char *kAsanHandleNoReturnName = "__asan_handle_no_return";
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static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
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static const char *kAsanMappingScaleName = "__asan_mapping_scale";
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static const char *kAsanStackMallocName = "__asan_stack_malloc";
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static const char *kAsanStackFreeName = "__asan_stack_free";
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static const int kAsanStackLeftRedzoneMagic = 0xf1;
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static const int kAsanStackMidRedzoneMagic = 0xf2;
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static const int kAsanStackRightRedzoneMagic = 0xf3;
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static const int kAsanStackPartialRedzoneMagic = 0xf4;
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// Accesses sizes are powers of two: 1, 2, 4, 8, 16.
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static const size_t kNumberOfAccessSizes = 5;
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// Command-line flags.
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// This flag may need to be replaced with -f[no-]asan-reads.
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static cl::opt<bool> ClInstrumentReads("asan-instrument-reads",
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cl::desc("instrument read instructions"), cl::Hidden, cl::init(true));
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static cl::opt<bool> ClInstrumentWrites("asan-instrument-writes",
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cl::desc("instrument write instructions"), cl::Hidden, cl::init(true));
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static cl::opt<bool> ClInstrumentAtomics("asan-instrument-atomics",
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cl::desc("instrument atomic instructions (rmw, cmpxchg)"),
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cl::Hidden, cl::init(true));
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static cl::opt<bool> ClAlwaysSlowPath("asan-always-slow-path",
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cl::desc("use instrumentation with slow path for all accesses"),
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cl::Hidden, cl::init(false));
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// This flag limits the number of instructions to be instrumented
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// in any given BB. Normally, this should be set to unlimited (INT_MAX),
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// but due to http://llvm.org/bugs/show_bug.cgi?id=12652 we temporary
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// set it to 10000.
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static cl::opt<int> ClMaxInsnsToInstrumentPerBB("asan-max-ins-per-bb",
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cl::init(10000),
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cl::desc("maximal number of instructions to instrument in any given BB"),
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cl::Hidden);
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// This flag may need to be replaced with -f[no]asan-stack.
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static cl::opt<bool> ClStack("asan-stack",
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cl::desc("Handle stack memory"), cl::Hidden, cl::init(true));
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// This flag may need to be replaced with -f[no]asan-use-after-return.
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static cl::opt<bool> ClUseAfterReturn("asan-use-after-return",
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cl::desc("Check return-after-free"), cl::Hidden, cl::init(false));
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// This flag may need to be replaced with -f[no]asan-globals.
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static cl::opt<bool> ClGlobals("asan-globals",
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cl::desc("Handle global objects"), cl::Hidden, cl::init(true));
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static cl::opt<bool> ClInitializers("asan-initialization-order",
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cl::desc("Handle C++ initializer order"), cl::Hidden, cl::init(false));
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static cl::opt<bool> ClMemIntrin("asan-memintrin",
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cl::desc("Handle memset/memcpy/memmove"), cl::Hidden, cl::init(true));
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// This flag may need to be replaced with -fasan-blacklist.
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static cl::opt<std::string> ClBlackListFile("asan-blacklist",
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cl::desc("File containing the list of functions to ignore "
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"during instrumentation"), cl::Hidden);
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// These flags allow to change the shadow mapping.
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// The shadow mapping looks like
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// Shadow = (Mem >> scale) + (1 << offset_log)
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static cl::opt<int> ClMappingScale("asan-mapping-scale",
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cl::desc("scale of asan shadow mapping"), cl::Hidden, cl::init(0));
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static cl::opt<int> ClMappingOffsetLog("asan-mapping-offset-log",
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cl::desc("offset of asan shadow mapping"), cl::Hidden, cl::init(-1));
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// Optimization flags. Not user visible, used mostly for testing
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// and benchmarking the tool.
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static cl::opt<bool> ClOpt("asan-opt",
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cl::desc("Optimize instrumentation"), cl::Hidden, cl::init(true));
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static cl::opt<bool> ClOptSameTemp("asan-opt-same-temp",
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cl::desc("Instrument the same temp just once"), cl::Hidden,
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cl::init(true));
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static cl::opt<bool> ClOptGlobals("asan-opt-globals",
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cl::desc("Don't instrument scalar globals"), cl::Hidden, cl::init(true));
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// Debug flags.
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static cl::opt<int> ClDebug("asan-debug", cl::desc("debug"), cl::Hidden,
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cl::init(0));
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static cl::opt<int> ClDebugStack("asan-debug-stack", cl::desc("debug stack"),
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cl::Hidden, cl::init(0));
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static cl::opt<std::string> ClDebugFunc("asan-debug-func",
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cl::Hidden, cl::desc("Debug func"));
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static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
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cl::Hidden, cl::init(-1));
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static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug man inst"),
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cl::Hidden, cl::init(-1));
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namespace {
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/// An object of this type is created while instrumenting every function.
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struct AsanFunctionContext {
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AsanFunctionContext(Function &Function) : F(Function) { }
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Function &F;
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};
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/// AddressSanitizer: instrument the code in module to find memory bugs.
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struct AddressSanitizer : public ModulePass {
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AddressSanitizer();
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virtual const char *getPassName() const;
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void instrumentMop(AsanFunctionContext &AFC, Instruction *I);
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void instrumentAddress(AsanFunctionContext &AFC,
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Instruction *OrigIns, IRBuilder<> &IRB,
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Value *Addr, uint32_t TypeSize, bool IsWrite);
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Value *createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
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Value *ShadowValue, uint32_t TypeSize);
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Instruction *generateCrashCode(Instruction *InsertBefore, Value *Addr,
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bool IsWrite, size_t AccessSizeIndex);
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bool instrumentMemIntrinsic(AsanFunctionContext &AFC, MemIntrinsic *MI);
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void instrumentMemIntrinsicParam(AsanFunctionContext &AFC,
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Instruction *OrigIns, Value *Addr,
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Value *Size,
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Instruction *InsertBefore, bool IsWrite);
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Value *memToShadow(Value *Shadow, IRBuilder<> &IRB);
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bool handleFunction(Module &M, Function &F);
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void createInitializerPoisonCalls(Module &M,
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Value *FirstAddr, Value *LastAddr);
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bool maybeInsertAsanInitAtFunctionEntry(Function &F);
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bool poisonStackInFunction(Module &M, Function &F);
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virtual bool runOnModule(Module &M);
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bool insertGlobalRedzones(Module &M);
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static char ID; // Pass identification, replacement for typeid
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private:
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uint64_t getAllocaSizeInBytes(AllocaInst *AI) {
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Type *Ty = AI->getAllocatedType();
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uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
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return SizeInBytes;
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}
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uint64_t getAlignedSize(uint64_t SizeInBytes) {
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return ((SizeInBytes + RedzoneSize - 1)
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/ RedzoneSize) * RedzoneSize;
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}
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uint64_t getAlignedAllocaSize(AllocaInst *AI) {
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uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
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return getAlignedSize(SizeInBytes);
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}
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Function *checkInterfaceFunction(Constant *FuncOrBitcast);
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bool ShouldInstrumentGlobal(GlobalVariable *G);
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void PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec, IRBuilder<> IRB,
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Value *ShadowBase, bool DoPoison);
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bool LooksLikeCodeInBug11395(Instruction *I);
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void FindDynamicInitializers(Module &M);
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bool HasDynamicInitializer(GlobalVariable *G);
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LLVMContext *C;
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TargetData *TD;
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uint64_t MappingOffset;
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int MappingScale;
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size_t RedzoneSize;
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int LongSize;
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Type *IntptrTy;
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Type *IntptrPtrTy;
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Function *AsanCtorFunction;
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Function *AsanInitFunction;
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Instruction *CtorInsertBefore;
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OwningPtr<BlackList> BL;
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// This array is indexed by AccessIsWrite and log2(AccessSize).
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Function *AsanErrorCallback[2][kNumberOfAccessSizes];
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InlineAsm *EmptyAsm;
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SmallSet<GlobalValue*, 32> DynamicallyInitializedGlobals;
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};
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} // namespace
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char AddressSanitizer::ID = 0;
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INITIALIZE_PASS(AddressSanitizer, "asan",
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"AddressSanitizer: detects use-after-free and out-of-bounds bugs.",
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false, false)
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AddressSanitizer::AddressSanitizer() : ModulePass(ID) { }
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ModulePass *llvm::createAddressSanitizerPass() {
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return new AddressSanitizer();
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}
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const char *AddressSanitizer::getPassName() const {
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return "AddressSanitizer";
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}
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static size_t TypeSizeToSizeIndex(uint32_t TypeSize) {
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size_t Res = CountTrailingZeros_32(TypeSize / 8);
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assert(Res < kNumberOfAccessSizes);
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return Res;
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}
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// Create a constant for Str so that we can pass it to the run-time lib.
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static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
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Constant *StrConst = ConstantDataArray::getString(M.getContext(), Str);
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return new GlobalVariable(M, StrConst->getType(), true,
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GlobalValue::PrivateLinkage, StrConst, "");
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}
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// Split the basic block and insert an if-then code.
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// Before:
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// Head
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// Cmp
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// Tail
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// After:
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// Head
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// if (Cmp)
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// ThenBlock
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// Tail
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//
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// ThenBlock block is created and its terminator is returned.
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// If Unreachable, ThenBlock is terminated with UnreachableInst, otherwise
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// it is terminated with BranchInst to Tail.
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static TerminatorInst *splitBlockAndInsertIfThen(Value *Cmp, bool Unreachable) {
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Instruction *SplitBefore = cast<Instruction>(Cmp)->getNextNode();
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BasicBlock *Head = SplitBefore->getParent();
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BasicBlock *Tail = Head->splitBasicBlock(SplitBefore);
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TerminatorInst *HeadOldTerm = Head->getTerminator();
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LLVMContext &C = Head->getParent()->getParent()->getContext();
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BasicBlock *ThenBlock = BasicBlock::Create(C, "", Head->getParent(), Tail);
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TerminatorInst *CheckTerm;
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if (Unreachable)
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CheckTerm = new UnreachableInst(C, ThenBlock);
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else
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CheckTerm = BranchInst::Create(Tail, ThenBlock);
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BranchInst *HeadNewTerm =
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BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/Tail, Cmp);
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ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
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return CheckTerm;
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}
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Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
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// Shadow >> scale
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Shadow = IRB.CreateLShr(Shadow, MappingScale);
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if (MappingOffset == 0)
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return Shadow;
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// (Shadow >> scale) | offset
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return IRB.CreateOr(Shadow, ConstantInt::get(IntptrTy,
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MappingOffset));
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}
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void AddressSanitizer::instrumentMemIntrinsicParam(
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AsanFunctionContext &AFC, Instruction *OrigIns,
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Value *Addr, Value *Size, Instruction *InsertBefore, bool IsWrite) {
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// Check the first byte.
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{
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IRBuilder<> IRB(InsertBefore);
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instrumentAddress(AFC, OrigIns, IRB, Addr, 8, IsWrite);
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}
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// Check the last byte.
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{
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IRBuilder<> IRB(InsertBefore);
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Value *SizeMinusOne = IRB.CreateSub(
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Size, ConstantInt::get(Size->getType(), 1));
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SizeMinusOne = IRB.CreateIntCast(SizeMinusOne, IntptrTy, false);
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Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
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Value *AddrPlusSizeMinisOne = IRB.CreateAdd(AddrLong, SizeMinusOne);
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instrumentAddress(AFC, OrigIns, IRB, AddrPlusSizeMinisOne, 8, IsWrite);
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}
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}
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// Instrument memset/memmove/memcpy
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bool AddressSanitizer::instrumentMemIntrinsic(AsanFunctionContext &AFC,
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MemIntrinsic *MI) {
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Value *Dst = MI->getDest();
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MemTransferInst *MemTran = dyn_cast<MemTransferInst>(MI);
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Value *Src = MemTran ? MemTran->getSource() : 0;
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Value *Length = MI->getLength();
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Constant *ConstLength = dyn_cast<Constant>(Length);
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Instruction *InsertBefore = MI;
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if (ConstLength) {
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if (ConstLength->isNullValue()) return false;
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} else {
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// The size is not a constant so it could be zero -- check at run-time.
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IRBuilder<> IRB(InsertBefore);
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Value *Cmp = IRB.CreateICmpNE(Length,
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Constant::getNullValue(Length->getType()));
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InsertBefore = splitBlockAndInsertIfThen(Cmp, false);
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}
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instrumentMemIntrinsicParam(AFC, MI, Dst, Length, InsertBefore, true);
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if (Src)
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instrumentMemIntrinsicParam(AFC, MI, Src, Length, InsertBefore, false);
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return true;
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}
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// If I is an interesting memory access, return the PointerOperand
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// and set IsWrite. Otherwise return NULL.
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static Value *isInterestingMemoryAccess(Instruction *I, bool *IsWrite) {
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if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
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if (!ClInstrumentReads) return NULL;
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*IsWrite = false;
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return LI->getPointerOperand();
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}
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if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
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if (!ClInstrumentWrites) return NULL;
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*IsWrite = true;
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return SI->getPointerOperand();
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}
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if (AtomicRMWInst *RMW = dyn_cast<AtomicRMWInst>(I)) {
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if (!ClInstrumentAtomics) return NULL;
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*IsWrite = true;
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return RMW->getPointerOperand();
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}
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if (AtomicCmpXchgInst *XCHG = dyn_cast<AtomicCmpXchgInst>(I)) {
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if (!ClInstrumentAtomics) return NULL;
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*IsWrite = true;
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return XCHG->getPointerOperand();
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}
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return NULL;
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}
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void AddressSanitizer::FindDynamicInitializers(Module& M) {
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// Clang generates metadata identifying all dynamically initialized globals.
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NamedMDNode *DynamicGlobals =
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M.getNamedMetadata("llvm.asan.dynamically_initialized_globals");
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if (!DynamicGlobals)
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return;
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for (int i = 0, n = DynamicGlobals->getNumOperands(); i < n; ++i) {
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MDNode *MDN = DynamicGlobals->getOperand(i);
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assert(MDN->getNumOperands() == 1);
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Value *VG = MDN->getOperand(0);
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// The optimizer may optimize away a global entirely, in which case we
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// cannot instrument access to it.
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if (!VG)
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continue;
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GlobalVariable *G = cast<GlobalVariable>(VG);
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DynamicallyInitializedGlobals.insert(G);
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}
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}
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// Returns true if a global variable is initialized dynamically in this TU.
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bool AddressSanitizer::HasDynamicInitializer(GlobalVariable *G) {
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return DynamicallyInitializedGlobals.count(G);
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}
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void AddressSanitizer::instrumentMop(AsanFunctionContext &AFC, Instruction *I) {
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bool IsWrite;
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Value *Addr = isInterestingMemoryAccess(I, &IsWrite);
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assert(Addr);
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if (ClOpt && ClOptGlobals) {
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if (GlobalVariable *G = dyn_cast<GlobalVariable>(Addr)) {
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// If initialization order checking is disabled, a simple access to a
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// dynamically initialized global is always valid.
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if (!ClInitializers)
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return;
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// If a global variable does not have dynamic initialization we don't
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// have to instrument it. However, if a global has external linkage, we
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// assume it has dynamic initialization, as it may have an initializer
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// in a different TU.
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if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
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!HasDynamicInitializer(G))
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return;
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}
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}
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Type *OrigPtrTy = Addr->getType();
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Type *OrigTy = cast<PointerType>(OrigPtrTy)->getElementType();
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assert(OrigTy->isSized());
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uint32_t TypeSize = TD->getTypeStoreSizeInBits(OrigTy);
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if (TypeSize != 8 && TypeSize != 16 &&
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TypeSize != 32 && TypeSize != 64 && TypeSize != 128) {
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// Ignore all unusual sizes.
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return;
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}
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IRBuilder<> IRB(I);
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instrumentAddress(AFC, I, IRB, Addr, TypeSize, IsWrite);
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}
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// Validate the result of Module::getOrInsertFunction called for an interface
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// function of AddressSanitizer. If the instrumented module defines a function
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// with the same name, their prototypes must match, otherwise
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// getOrInsertFunction returns a bitcast.
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|
Function *AddressSanitizer::checkInterfaceFunction(Constant *FuncOrBitcast) {
|
|
if (isa<Function>(FuncOrBitcast)) return cast<Function>(FuncOrBitcast);
|
|
FuncOrBitcast->dump();
|
|
report_fatal_error("trying to redefine an AddressSanitizer "
|
|
"interface function");
|
|
}
|
|
|
|
Instruction *AddressSanitizer::generateCrashCode(
|
|
Instruction *InsertBefore, Value *Addr,
|
|
bool IsWrite, size_t AccessSizeIndex) {
|
|
IRBuilder<> IRB(InsertBefore);
|
|
CallInst *Call = IRB.CreateCall(AsanErrorCallback[IsWrite][AccessSizeIndex],
|
|
Addr);
|
|
// We don't do Call->setDoesNotReturn() because the BB already has
|
|
// UnreachableInst at the end.
|
|
// This EmptyAsm is required to avoid callback merge.
|
|
IRB.CreateCall(EmptyAsm);
|
|
return Call;
|
|
}
|
|
|
|
Value *AddressSanitizer::createSlowPathCmp(IRBuilder<> &IRB, Value *AddrLong,
|
|
Value *ShadowValue,
|
|
uint32_t TypeSize) {
|
|
size_t Granularity = 1 << MappingScale;
|
|
// 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);
|
|
}
|
|
|
|
void AddressSanitizer::instrumentAddress(AsanFunctionContext &AFC,
|
|
Instruction *OrigIns,
|
|
IRBuilder<> &IRB, Value *Addr,
|
|
uint32_t TypeSize, bool IsWrite) {
|
|
Value *AddrLong = IRB.CreatePointerCast(Addr, IntptrTy);
|
|
|
|
Type *ShadowTy = IntegerType::get(
|
|
*C, std::max(8U, TypeSize >> MappingScale));
|
|
Type *ShadowPtrTy = PointerType::get(ShadowTy, 0);
|
|
Value *ShadowPtr = memToShadow(AddrLong, IRB);
|
|
Value *CmpVal = Constant::getNullValue(ShadowTy);
|
|
Value *ShadowValue = IRB.CreateLoad(
|
|
IRB.CreateIntToPtr(ShadowPtr, ShadowPtrTy));
|
|
|
|
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
|
|
size_t AccessSizeIndex = TypeSizeToSizeIndex(TypeSize);
|
|
size_t Granularity = 1 << MappingScale;
|
|
TerminatorInst *CrashTerm = 0;
|
|
|
|
if (ClAlwaysSlowPath || (TypeSize < 8 * Granularity)) {
|
|
TerminatorInst *CheckTerm = splitBlockAndInsertIfThen(Cmp, false);
|
|
assert(dyn_cast<BranchInst>(CheckTerm)->isUnconditional());
|
|
BasicBlock *NextBB = CheckTerm->getSuccessor(0);
|
|
IRB.SetInsertPoint(CheckTerm);
|
|
Value *Cmp2 = createSlowPathCmp(IRB, AddrLong, ShadowValue, TypeSize);
|
|
BasicBlock *CrashBlock = BasicBlock::Create(*C, "", &AFC.F, NextBB);
|
|
CrashTerm = new UnreachableInst(*C, CrashBlock);
|
|
BranchInst *NewTerm = BranchInst::Create(CrashBlock, NextBB, Cmp2);
|
|
ReplaceInstWithInst(CheckTerm, NewTerm);
|
|
} else {
|
|
CrashTerm = splitBlockAndInsertIfThen(Cmp, true);
|
|
}
|
|
|
|
Instruction *Crash =
|
|
generateCrashCode(CrashTerm, AddrLong, IsWrite, AccessSizeIndex);
|
|
Crash->setDebugLoc(OrigIns->getDebugLoc());
|
|
}
|
|
|
|
void AddressSanitizer::createInitializerPoisonCalls(Module &M,
|
|
Value *FirstAddr,
|
|
Value *LastAddr) {
|
|
// We do all of our poisoning and unpoisoning within _GLOBAL__I_a.
|
|
Function *GlobalInit = M.getFunction("_GLOBAL__I_a");
|
|
// If that function is not present, this TU contains no globals, or they have
|
|
// all been optimized away
|
|
if (!GlobalInit)
|
|
return;
|
|
|
|
// Set up the arguments to our poison/unpoison functions.
|
|
IRBuilder<> IRB(GlobalInit->begin()->getFirstInsertionPt());
|
|
|
|
// Declare our poisoning and unpoisoning functions.
|
|
Function *AsanPoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
|
|
kAsanPoisonGlobalsName, IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
|
|
AsanPoisonGlobals->setLinkage(Function::ExternalLinkage);
|
|
Function *AsanUnpoisonGlobals = checkInterfaceFunction(M.getOrInsertFunction(
|
|
kAsanUnpoisonGlobalsName, IRB.getVoidTy(), NULL));
|
|
AsanUnpoisonGlobals->setLinkage(Function::ExternalLinkage);
|
|
|
|
// Add a call to poison all external globals before the given function starts.
|
|
IRB.CreateCall2(AsanPoisonGlobals, FirstAddr, LastAddr);
|
|
|
|
// Add calls to unpoison all globals before each return instruction.
|
|
for (Function::iterator I = GlobalInit->begin(), E = GlobalInit->end();
|
|
I != E; ++I) {
|
|
if (ReturnInst *RI = dyn_cast<ReturnInst>(I->getTerminator())) {
|
|
CallInst::Create(AsanUnpoisonGlobals, "", RI);
|
|
}
|
|
}
|
|
}
|
|
|
|
bool AddressSanitizer::ShouldInstrumentGlobal(GlobalVariable *G) {
|
|
Type *Ty = cast<PointerType>(G->getType())->getElementType();
|
|
DEBUG(dbgs() << "GLOBAL: " << *G);
|
|
|
|
if (!Ty->isSized()) return false;
|
|
if (!G->hasInitializer()) return false;
|
|
// Touch only those globals that will not be defined in other modules.
|
|
// Don't handle ODR type linkages since other modules may be built w/o asan.
|
|
if (G->getLinkage() != GlobalVariable::ExternalLinkage &&
|
|
G->getLinkage() != GlobalVariable::PrivateLinkage &&
|
|
G->getLinkage() != GlobalVariable::InternalLinkage)
|
|
return false;
|
|
// 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 Alloca if the alignment is large.
|
|
if (G->getAlignment() > RedzoneSize) return false;
|
|
|
|
// Ignore all the globals with the names starting with "\01L_OBJC_".
|
|
// Many of those are put into the .cstring section. The linker compresses
|
|
// that section by removing the spare \0s after the string terminator, so
|
|
// our redzones get broken.
|
|
if ((G->getName().find("\01L_OBJC_") == 0) ||
|
|
(G->getName().find("\01l_OBJC_") == 0)) {
|
|
DEBUG(dbgs() << "Ignoring \\01L_OBJC_* global: " << *G);
|
|
return false;
|
|
}
|
|
|
|
if (G->hasSection()) {
|
|
StringRef Section(G->getSection());
|
|
// 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 ((Section.find("__OBJC,") == 0) ||
|
|
(Section.find("__DATA, __objc_") == 0)) {
|
|
DEBUG(dbgs() << "Ignoring ObjC runtime global: " << *G);
|
|
return false;
|
|
}
|
|
// See http://code.google.com/p/address-sanitizer/issues/detail?id=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 (Section.find("__DATA,__cfstring") == 0) {
|
|
DEBUG(dbgs() << "Ignoring CFString: " << *G);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// This function replaces all global variables with new variables that have
|
|
// trailing redzones. It also creates a function that poisons
|
|
// redzones and inserts this function into llvm.global_ctors.
|
|
bool AddressSanitizer::insertGlobalRedzones(Module &M) {
|
|
SmallVector<GlobalVariable *, 16> GlobalsToChange;
|
|
|
|
for (Module::GlobalListType::iterator G = M.global_begin(),
|
|
E = M.global_end(); G != E; ++G) {
|
|
if (ShouldInstrumentGlobal(G))
|
|
GlobalsToChange.push_back(G);
|
|
}
|
|
|
|
size_t n = GlobalsToChange.size();
|
|
if (n == 0) return false;
|
|
|
|
// A global is described by a structure
|
|
// size_t beg;
|
|
// size_t size;
|
|
// size_t size_with_redzone;
|
|
// const char *name;
|
|
// size_t has_dynamic_init;
|
|
// We initialize an array of such structures and pass it to a run-time call.
|
|
StructType *GlobalStructTy = StructType::get(IntptrTy, IntptrTy,
|
|
IntptrTy, IntptrTy,
|
|
IntptrTy, NULL);
|
|
SmallVector<Constant *, 16> Initializers(n), DynamicInit;
|
|
|
|
IRBuilder<> IRB(CtorInsertBefore);
|
|
|
|
if (ClInitializers)
|
|
FindDynamicInitializers(M);
|
|
|
|
// The addresses of the first and last dynamically initialized globals in
|
|
// this TU. Used in initialization order checking.
|
|
Value *FirstDynamic = 0, *LastDynamic = 0;
|
|
|
|
for (size_t i = 0; i < n; i++) {
|
|
GlobalVariable *G = GlobalsToChange[i];
|
|
PointerType *PtrTy = cast<PointerType>(G->getType());
|
|
Type *Ty = PtrTy->getElementType();
|
|
uint64_t SizeInBytes = TD->getTypeAllocSize(Ty);
|
|
uint64_t RightRedzoneSize = RedzoneSize +
|
|
(RedzoneSize - (SizeInBytes % RedzoneSize));
|
|
Type *RightRedZoneTy = ArrayType::get(IRB.getInt8Ty(), RightRedzoneSize);
|
|
// Determine whether this global should be poisoned in initialization.
|
|
bool GlobalHasDynamicInitializer = HasDynamicInitializer(G);
|
|
|
|
StructType *NewTy = StructType::get(Ty, RightRedZoneTy, NULL);
|
|
Constant *NewInitializer = ConstantStruct::get(
|
|
NewTy, G->getInitializer(),
|
|
Constant::getNullValue(RightRedZoneTy), NULL);
|
|
|
|
SmallString<2048> DescriptionOfGlobal = G->getName();
|
|
DescriptionOfGlobal += " (";
|
|
DescriptionOfGlobal += M.getModuleIdentifier();
|
|
DescriptionOfGlobal += ")";
|
|
GlobalVariable *Name = createPrivateGlobalForString(M, DescriptionOfGlobal);
|
|
|
|
// Create a new global variable with enough space for a redzone.
|
|
GlobalVariable *NewGlobal = new GlobalVariable(
|
|
M, NewTy, G->isConstant(), G->getLinkage(),
|
|
NewInitializer, "", G, G->getThreadLocalMode());
|
|
NewGlobal->copyAttributesFrom(G);
|
|
NewGlobal->setAlignment(RedzoneSize);
|
|
|
|
Value *Indices2[2];
|
|
Indices2[0] = IRB.getInt32(0);
|
|
Indices2[1] = IRB.getInt32(0);
|
|
|
|
G->replaceAllUsesWith(
|
|
ConstantExpr::getGetElementPtr(NewGlobal, Indices2, true));
|
|
NewGlobal->takeName(G);
|
|
G->eraseFromParent();
|
|
|
|
Initializers[i] = ConstantStruct::get(
|
|
GlobalStructTy,
|
|
ConstantExpr::getPointerCast(NewGlobal, IntptrTy),
|
|
ConstantInt::get(IntptrTy, SizeInBytes),
|
|
ConstantInt::get(IntptrTy, SizeInBytes + RightRedzoneSize),
|
|
ConstantExpr::getPointerCast(Name, IntptrTy),
|
|
ConstantInt::get(IntptrTy, GlobalHasDynamicInitializer),
|
|
NULL);
|
|
|
|
// Populate the first and last globals declared in this TU.
|
|
if (ClInitializers && GlobalHasDynamicInitializer) {
|
|
LastDynamic = ConstantExpr::getPointerCast(NewGlobal, IntptrTy);
|
|
if (FirstDynamic == 0)
|
|
FirstDynamic = LastDynamic;
|
|
}
|
|
|
|
DEBUG(dbgs() << "NEW GLOBAL:\n" << *NewGlobal);
|
|
}
|
|
|
|
ArrayType *ArrayOfGlobalStructTy = ArrayType::get(GlobalStructTy, n);
|
|
GlobalVariable *AllGlobals = new GlobalVariable(
|
|
M, ArrayOfGlobalStructTy, false, GlobalVariable::PrivateLinkage,
|
|
ConstantArray::get(ArrayOfGlobalStructTy, Initializers), "");
|
|
|
|
// Create calls for poisoning before initializers run and unpoisoning after.
|
|
if (ClInitializers && FirstDynamic && LastDynamic)
|
|
createInitializerPoisonCalls(M, FirstDynamic, LastDynamic);
|
|
|
|
Function *AsanRegisterGlobals = checkInterfaceFunction(M.getOrInsertFunction(
|
|
kAsanRegisterGlobalsName, IRB.getVoidTy(),
|
|
IntptrTy, IntptrTy, NULL));
|
|
AsanRegisterGlobals->setLinkage(Function::ExternalLinkage);
|
|
|
|
IRB.CreateCall2(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.
|
|
Function *AsanDtorFunction = Function::Create(
|
|
FunctionType::get(Type::getVoidTy(*C), false),
|
|
GlobalValue::InternalLinkage, kAsanModuleDtorName, &M);
|
|
BasicBlock *AsanDtorBB = BasicBlock::Create(*C, "", AsanDtorFunction);
|
|
IRBuilder<> IRB_Dtor(ReturnInst::Create(*C, AsanDtorBB));
|
|
Function *AsanUnregisterGlobals =
|
|
checkInterfaceFunction(M.getOrInsertFunction(
|
|
kAsanUnregisterGlobalsName,
|
|
IRB.getVoidTy(), IntptrTy, IntptrTy, NULL));
|
|
AsanUnregisterGlobals->setLinkage(Function::ExternalLinkage);
|
|
|
|
IRB_Dtor.CreateCall2(AsanUnregisterGlobals,
|
|
IRB.CreatePointerCast(AllGlobals, IntptrTy),
|
|
ConstantInt::get(IntptrTy, n));
|
|
appendToGlobalDtors(M, AsanDtorFunction, kAsanCtorAndCtorPriority);
|
|
|
|
DEBUG(dbgs() << M);
|
|
return true;
|
|
}
|
|
|
|
// virtual
|
|
bool AddressSanitizer::runOnModule(Module &M) {
|
|
// Initialize the private fields. No one has accessed them before.
|
|
TD = getAnalysisIfAvailable<TargetData>();
|
|
if (!TD)
|
|
return false;
|
|
BL.reset(new BlackList(ClBlackListFile));
|
|
|
|
C = &(M.getContext());
|
|
LongSize = TD->getPointerSizeInBits();
|
|
IntptrTy = Type::getIntNTy(*C, LongSize);
|
|
IntptrPtrTy = PointerType::get(IntptrTy, 0);
|
|
|
|
AsanCtorFunction = Function::Create(
|
|
FunctionType::get(Type::getVoidTy(*C), false),
|
|
GlobalValue::InternalLinkage, kAsanModuleCtorName, &M);
|
|
BasicBlock *AsanCtorBB = BasicBlock::Create(*C, "", AsanCtorFunction);
|
|
CtorInsertBefore = ReturnInst::Create(*C, AsanCtorBB);
|
|
|
|
// call __asan_init in the module ctor.
|
|
IRBuilder<> IRB(CtorInsertBefore);
|
|
AsanInitFunction = checkInterfaceFunction(
|
|
M.getOrInsertFunction(kAsanInitName, IRB.getVoidTy(), NULL));
|
|
AsanInitFunction->setLinkage(Function::ExternalLinkage);
|
|
IRB.CreateCall(AsanInitFunction);
|
|
|
|
// Create __asan_report* callbacks.
|
|
for (size_t AccessIsWrite = 0; AccessIsWrite <= 1; AccessIsWrite++) {
|
|
for (size_t AccessSizeIndex = 0; AccessSizeIndex < kNumberOfAccessSizes;
|
|
AccessSizeIndex++) {
|
|
// IsWrite and TypeSize are encoded in the function name.
|
|
std::string FunctionName = std::string(kAsanReportErrorTemplate) +
|
|
(AccessIsWrite ? "store" : "load") + itostr(1 << AccessSizeIndex);
|
|
// If we are merging crash callbacks, they have two parameters.
|
|
AsanErrorCallback[AccessIsWrite][AccessSizeIndex] = cast<Function>(
|
|
M.getOrInsertFunction(FunctionName, IRB.getVoidTy(), IntptrTy, NULL));
|
|
}
|
|
}
|
|
// We insert an empty inline asm after __asan_report* to avoid callback merge.
|
|
EmptyAsm = InlineAsm::get(FunctionType::get(IRB.getVoidTy(), false),
|
|
StringRef(""), StringRef(""),
|
|
/*hasSideEffects=*/true);
|
|
|
|
llvm::Triple targetTriple(M.getTargetTriple());
|
|
bool isAndroid = targetTriple.getEnvironment() == llvm::Triple::ANDROIDEABI;
|
|
|
|
MappingOffset = isAndroid ? kDefaultShadowOffsetAndroid :
|
|
(LongSize == 32 ? kDefaultShadowOffset32 : kDefaultShadowOffset64);
|
|
if (ClMappingOffsetLog >= 0) {
|
|
if (ClMappingOffsetLog == 0) {
|
|
// special case
|
|
MappingOffset = 0;
|
|
} else {
|
|
MappingOffset = 1ULL << ClMappingOffsetLog;
|
|
}
|
|
}
|
|
MappingScale = kDefaultShadowScale;
|
|
if (ClMappingScale) {
|
|
MappingScale = ClMappingScale;
|
|
}
|
|
// 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.
|
|
RedzoneSize = std::max(32, (int)(1 << MappingScale));
|
|
|
|
bool Res = false;
|
|
|
|
if (ClGlobals)
|
|
Res |= insertGlobalRedzones(M);
|
|
|
|
if (ClMappingOffsetLog >= 0) {
|
|
// Tell the run-time the current values of mapping offset and scale.
|
|
GlobalValue *asan_mapping_offset =
|
|
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
|
|
ConstantInt::get(IntptrTy, MappingOffset),
|
|
kAsanMappingOffsetName);
|
|
// Read the global, otherwise it may be optimized away.
|
|
IRB.CreateLoad(asan_mapping_offset, true);
|
|
}
|
|
if (ClMappingScale) {
|
|
GlobalValue *asan_mapping_scale =
|
|
new GlobalVariable(M, IntptrTy, true, GlobalValue::LinkOnceODRLinkage,
|
|
ConstantInt::get(IntptrTy, MappingScale),
|
|
kAsanMappingScaleName);
|
|
// Read the global, otherwise it may be optimized away.
|
|
IRB.CreateLoad(asan_mapping_scale, true);
|
|
}
|
|
|
|
|
|
for (Module::iterator F = M.begin(), E = M.end(); F != E; ++F) {
|
|
if (F->isDeclaration()) continue;
|
|
Res |= handleFunction(M, *F);
|
|
}
|
|
|
|
appendToGlobalCtors(M, AsanCtorFunction, kAsanCtorAndCtorPriority);
|
|
|
|
return Res;
|
|
}
|
|
|
|
bool 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) {
|
|
IRBuilder<> IRB(F.begin()->begin());
|
|
IRB.CreateCall(AsanInitFunction);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
bool AddressSanitizer::handleFunction(Module &M, Function &F) {
|
|
if (BL->isIn(F)) return false;
|
|
if (&F == AsanCtorFunction) return false;
|
|
|
|
// If needed, insert __asan_init before checking for AddressSafety attr.
|
|
maybeInsertAsanInitAtFunctionEntry(F);
|
|
|
|
if (!F.hasFnAttr(Attribute::AddressSafety)) return false;
|
|
|
|
if (!ClDebugFunc.empty() && ClDebugFunc != F.getName())
|
|
return false;
|
|
// We want to instrument every address only once per basic block
|
|
// (unless there are calls between uses).
|
|
SmallSet<Value*, 16> TempsToInstrument;
|
|
SmallVector<Instruction*, 16> ToInstrument;
|
|
SmallVector<Instruction*, 8> NoReturnCalls;
|
|
bool IsWrite;
|
|
|
|
// Fill the set of memory operations to instrument.
|
|
for (Function::iterator FI = F.begin(), FE = F.end();
|
|
FI != FE; ++FI) {
|
|
TempsToInstrument.clear();
|
|
int NumInsnsPerBB = 0;
|
|
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
|
|
BI != BE; ++BI) {
|
|
if (LooksLikeCodeInBug11395(BI)) return false;
|
|
if (Value *Addr = isInterestingMemoryAccess(BI, &IsWrite)) {
|
|
if (ClOpt && ClOptSameTemp) {
|
|
if (!TempsToInstrument.insert(Addr))
|
|
continue; // We've seen this temp in the current BB.
|
|
}
|
|
} else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
|
|
// ok, take it.
|
|
} else {
|
|
if (CallInst *CI = dyn_cast<CallInst>(BI)) {
|
|
// A call inside BB.
|
|
TempsToInstrument.clear();
|
|
if (CI->doesNotReturn()) {
|
|
NoReturnCalls.push_back(CI);
|
|
}
|
|
}
|
|
continue;
|
|
}
|
|
ToInstrument.push_back(BI);
|
|
NumInsnsPerBB++;
|
|
if (NumInsnsPerBB >= ClMaxInsnsToInstrumentPerBB)
|
|
break;
|
|
}
|
|
}
|
|
|
|
AsanFunctionContext AFC(F);
|
|
|
|
// Instrument.
|
|
int NumInstrumented = 0;
|
|
for (size_t i = 0, n = ToInstrument.size(); i != n; i++) {
|
|
Instruction *Inst = ToInstrument[i];
|
|
if (ClDebugMin < 0 || ClDebugMax < 0 ||
|
|
(NumInstrumented >= ClDebugMin && NumInstrumented <= ClDebugMax)) {
|
|
if (isInterestingMemoryAccess(Inst, &IsWrite))
|
|
instrumentMop(AFC, Inst);
|
|
else
|
|
instrumentMemIntrinsic(AFC, cast<MemIntrinsic>(Inst));
|
|
}
|
|
NumInstrumented++;
|
|
}
|
|
|
|
DEBUG(dbgs() << F);
|
|
|
|
bool ChangedStack = poisonStackInFunction(M, F);
|
|
|
|
// We must unpoison the stack before every NoReturn call (throw, _exit, etc).
|
|
// See e.g. http://code.google.com/p/address-sanitizer/issues/detail?id=37
|
|
for (size_t i = 0, n = NoReturnCalls.size(); i != n; i++) {
|
|
Instruction *CI = NoReturnCalls[i];
|
|
IRBuilder<> IRB(CI);
|
|
IRB.CreateCall(M.getOrInsertFunction(kAsanHandleNoReturnName,
|
|
IRB.getVoidTy(), NULL));
|
|
}
|
|
|
|
return NumInstrumented > 0 || ChangedStack || !NoReturnCalls.empty();
|
|
}
|
|
|
|
static uint64_t ValueForPoison(uint64_t PoisonByte, size_t ShadowRedzoneSize) {
|
|
if (ShadowRedzoneSize == 1) return PoisonByte;
|
|
if (ShadowRedzoneSize == 2) return (PoisonByte << 8) + PoisonByte;
|
|
if (ShadowRedzoneSize == 4)
|
|
return (PoisonByte << 24) + (PoisonByte << 16) +
|
|
(PoisonByte << 8) + (PoisonByte);
|
|
llvm_unreachable("ShadowRedzoneSize is either 1, 2 or 4");
|
|
}
|
|
|
|
static void PoisonShadowPartialRightRedzone(uint8_t *Shadow,
|
|
size_t Size,
|
|
size_t RedzoneSize,
|
|
size_t ShadowGranularity,
|
|
uint8_t Magic) {
|
|
for (size_t i = 0; i < RedzoneSize;
|
|
i+= ShadowGranularity, Shadow++) {
|
|
if (i + ShadowGranularity <= Size) {
|
|
*Shadow = 0; // fully addressable
|
|
} else if (i >= Size) {
|
|
*Shadow = Magic; // unaddressable
|
|
} else {
|
|
*Shadow = Size - i; // first Size-i bytes are addressable
|
|
}
|
|
}
|
|
}
|
|
|
|
void AddressSanitizer::PoisonStack(const ArrayRef<AllocaInst*> &AllocaVec,
|
|
IRBuilder<> IRB,
|
|
Value *ShadowBase, bool DoPoison) {
|
|
size_t ShadowRZSize = RedzoneSize >> MappingScale;
|
|
assert(ShadowRZSize >= 1 && ShadowRZSize <= 4);
|
|
Type *RZTy = Type::getIntNTy(*C, ShadowRZSize * 8);
|
|
Type *RZPtrTy = PointerType::get(RZTy, 0);
|
|
|
|
Value *PoisonLeft = ConstantInt::get(RZTy,
|
|
ValueForPoison(DoPoison ? kAsanStackLeftRedzoneMagic : 0LL, ShadowRZSize));
|
|
Value *PoisonMid = ConstantInt::get(RZTy,
|
|
ValueForPoison(DoPoison ? kAsanStackMidRedzoneMagic : 0LL, ShadowRZSize));
|
|
Value *PoisonRight = ConstantInt::get(RZTy,
|
|
ValueForPoison(DoPoison ? kAsanStackRightRedzoneMagic : 0LL, ShadowRZSize));
|
|
|
|
// poison the first red zone.
|
|
IRB.CreateStore(PoisonLeft, IRB.CreateIntToPtr(ShadowBase, RZPtrTy));
|
|
|
|
// poison all other red zones.
|
|
uint64_t Pos = RedzoneSize;
|
|
for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
|
|
AllocaInst *AI = AllocaVec[i];
|
|
uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
|
|
uint64_t AlignedSize = getAlignedAllocaSize(AI);
|
|
assert(AlignedSize - SizeInBytes < RedzoneSize);
|
|
Value *Ptr = NULL;
|
|
|
|
Pos += AlignedSize;
|
|
|
|
assert(ShadowBase->getType() == IntptrTy);
|
|
if (SizeInBytes < AlignedSize) {
|
|
// Poison the partial redzone at right
|
|
Ptr = IRB.CreateAdd(
|
|
ShadowBase, ConstantInt::get(IntptrTy,
|
|
(Pos >> MappingScale) - ShadowRZSize));
|
|
size_t AddressableBytes = RedzoneSize - (AlignedSize - SizeInBytes);
|
|
uint32_t Poison = 0;
|
|
if (DoPoison) {
|
|
PoisonShadowPartialRightRedzone((uint8_t*)&Poison, AddressableBytes,
|
|
RedzoneSize,
|
|
1ULL << MappingScale,
|
|
kAsanStackPartialRedzoneMagic);
|
|
}
|
|
Value *PartialPoison = ConstantInt::get(RZTy, Poison);
|
|
IRB.CreateStore(PartialPoison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
|
|
}
|
|
|
|
// Poison the full redzone at right.
|
|
Ptr = IRB.CreateAdd(ShadowBase,
|
|
ConstantInt::get(IntptrTy, Pos >> MappingScale));
|
|
Value *Poison = i == AllocaVec.size() - 1 ? PoisonRight : PoisonMid;
|
|
IRB.CreateStore(Poison, IRB.CreateIntToPtr(Ptr, RZPtrTy));
|
|
|
|
Pos += RedzoneSize;
|
|
}
|
|
}
|
|
|
|
// Workaround for bug 11395: we don't want to instrument stack in functions
|
|
// with large assembly blobs (32-bit only), otherwise reg alloc may crash.
|
|
// FIXME: remove once the bug 11395 is fixed.
|
|
bool 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;
|
|
}
|
|
|
|
// Find all static Alloca instructions and put
|
|
// poisoned red zones around all of them.
|
|
// Then unpoison everything back before the function returns.
|
|
//
|
|
// Stack poisoning does not play well with exception handling.
|
|
// When an exception is thrown, we essentially bypass the code
|
|
// that unpoisones the stack. This is why the run-time library has
|
|
// to intercept __cxa_throw (as well as longjmp, etc) and unpoison the entire
|
|
// stack in the interceptor. This however does not work inside the
|
|
// actual function which catches the exception. Most likely because the
|
|
// compiler hoists the load of the shadow value somewhere too high.
|
|
// This causes asan to report a non-existing bug on 453.povray.
|
|
// It sounds like an LLVM bug.
|
|
bool AddressSanitizer::poisonStackInFunction(Module &M, Function &F) {
|
|
if (!ClStack) return false;
|
|
SmallVector<AllocaInst*, 16> AllocaVec;
|
|
SmallVector<Instruction*, 8> RetVec;
|
|
uint64_t TotalSize = 0;
|
|
|
|
// Filter out Alloca instructions we want (and can) handle.
|
|
// Collect Ret instructions.
|
|
for (Function::iterator FI = F.begin(), FE = F.end();
|
|
FI != FE; ++FI) {
|
|
BasicBlock &BB = *FI;
|
|
for (BasicBlock::iterator BI = BB.begin(), BE = BB.end();
|
|
BI != BE; ++BI) {
|
|
if (isa<ReturnInst>(BI)) {
|
|
RetVec.push_back(BI);
|
|
continue;
|
|
}
|
|
|
|
AllocaInst *AI = dyn_cast<AllocaInst>(BI);
|
|
if (!AI) continue;
|
|
if (AI->isArrayAllocation()) continue;
|
|
if (!AI->isStaticAlloca()) continue;
|
|
if (!AI->getAllocatedType()->isSized()) continue;
|
|
if (AI->getAlignment() > RedzoneSize) continue;
|
|
AllocaVec.push_back(AI);
|
|
uint64_t AlignedSize = getAlignedAllocaSize(AI);
|
|
TotalSize += AlignedSize;
|
|
}
|
|
}
|
|
|
|
if (AllocaVec.empty()) return false;
|
|
|
|
uint64_t LocalStackSize = TotalSize + (AllocaVec.size() + 1) * RedzoneSize;
|
|
|
|
bool DoStackMalloc = ClUseAfterReturn
|
|
&& LocalStackSize <= kMaxStackMallocSize;
|
|
|
|
Instruction *InsBefore = AllocaVec[0];
|
|
IRBuilder<> IRB(InsBefore);
|
|
|
|
|
|
Type *ByteArrayTy = ArrayType::get(IRB.getInt8Ty(), LocalStackSize);
|
|
AllocaInst *MyAlloca =
|
|
new AllocaInst(ByteArrayTy, "MyAlloca", InsBefore);
|
|
MyAlloca->setAlignment(RedzoneSize);
|
|
assert(MyAlloca->isStaticAlloca());
|
|
Value *OrigStackBase = IRB.CreatePointerCast(MyAlloca, IntptrTy);
|
|
Value *LocalStackBase = OrigStackBase;
|
|
|
|
if (DoStackMalloc) {
|
|
Value *AsanStackMallocFunc = M.getOrInsertFunction(
|
|
kAsanStackMallocName, IntptrTy, IntptrTy, IntptrTy, NULL);
|
|
LocalStackBase = IRB.CreateCall2(AsanStackMallocFunc,
|
|
ConstantInt::get(IntptrTy, LocalStackSize), OrigStackBase);
|
|
}
|
|
|
|
// This string will be parsed by the run-time (DescribeStackAddress).
|
|
SmallString<2048> StackDescriptionStorage;
|
|
raw_svector_ostream StackDescription(StackDescriptionStorage);
|
|
StackDescription << F.getName() << " " << AllocaVec.size() << " ";
|
|
|
|
uint64_t Pos = RedzoneSize;
|
|
// Replace Alloca instructions with base+offset.
|
|
for (size_t i = 0, n = AllocaVec.size(); i < n; i++) {
|
|
AllocaInst *AI = AllocaVec[i];
|
|
uint64_t SizeInBytes = getAllocaSizeInBytes(AI);
|
|
StringRef Name = AI->getName();
|
|
StackDescription << Pos << " " << SizeInBytes << " "
|
|
<< Name.size() << " " << Name << " ";
|
|
uint64_t AlignedSize = getAlignedAllocaSize(AI);
|
|
assert((AlignedSize % RedzoneSize) == 0);
|
|
AI->replaceAllUsesWith(
|
|
IRB.CreateIntToPtr(
|
|
IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)),
|
|
AI->getType()));
|
|
Pos += AlignedSize + RedzoneSize;
|
|
}
|
|
assert(Pos == LocalStackSize);
|
|
|
|
// Write the Magic value and the frame description constant to the redzone.
|
|
Value *BasePlus0 = IRB.CreateIntToPtr(LocalStackBase, IntptrPtrTy);
|
|
IRB.CreateStore(ConstantInt::get(IntptrTy, kCurrentStackFrameMagic),
|
|
BasePlus0);
|
|
Value *BasePlus1 = IRB.CreateAdd(LocalStackBase,
|
|
ConstantInt::get(IntptrTy, LongSize/8));
|
|
BasePlus1 = IRB.CreateIntToPtr(BasePlus1, IntptrPtrTy);
|
|
Value *Description = IRB.CreatePointerCast(
|
|
createPrivateGlobalForString(M, StackDescription.str()),
|
|
IntptrTy);
|
|
IRB.CreateStore(Description, BasePlus1);
|
|
|
|
// Poison the stack redzones at the entry.
|
|
Value *ShadowBase = memToShadow(LocalStackBase, IRB);
|
|
PoisonStack(ArrayRef<AllocaInst*>(AllocaVec), IRB, ShadowBase, true);
|
|
|
|
Value *AsanStackFreeFunc = NULL;
|
|
if (DoStackMalloc) {
|
|
AsanStackFreeFunc = M.getOrInsertFunction(
|
|
kAsanStackFreeName, IRB.getVoidTy(),
|
|
IntptrTy, IntptrTy, IntptrTy, NULL);
|
|
}
|
|
|
|
// Unpoison the stack before all ret instructions.
|
|
for (size_t i = 0, n = RetVec.size(); i < n; i++) {
|
|
Instruction *Ret = RetVec[i];
|
|
IRBuilder<> IRBRet(Ret);
|
|
|
|
// Mark the current frame as retired.
|
|
IRBRet.CreateStore(ConstantInt::get(IntptrTy, kRetiredStackFrameMagic),
|
|
BasePlus0);
|
|
// Unpoison the stack.
|
|
PoisonStack(ArrayRef<AllocaInst*>(AllocaVec), IRBRet, ShadowBase, false);
|
|
|
|
if (DoStackMalloc) {
|
|
IRBRet.CreateCall3(AsanStackFreeFunc, LocalStackBase,
|
|
ConstantInt::get(IntptrTy, LocalStackSize),
|
|
OrigStackBase);
|
|
}
|
|
}
|
|
|
|
if (ClDebugStack) {
|
|
DEBUG(dbgs() << F);
|
|
}
|
|
|
|
return true;
|
|
}
|