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[Msan] Generalize instrumentation code to support FreeBSD mapping 

Differential Revision: http://reviews.llvm.org/D6666

llvm-svn: 224514
This commit is contained in:
Viktor Kutuzov 2014-12-18 12:12:59 +00:00
parent 3a623dbd2a
commit b4ffb5d5e9
1 changed files with 106 additions and 27 deletions
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133
llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
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@ -120,10 +120,6 @@ using namespace llvm;
#define DEBUG_TYPE "msan"
static const uint64_t kShadowMask32 = 1ULL << 31;
static const uint64_t kShadowMask64 = 1ULL << 46;
static const uint64_t kOriginOffset32 = 1ULL << 30;
static const uint64_t kOriginOffset64 = 1ULL << 45;
static const unsigned kMinOriginAlignment = 4;
static const unsigned kShadowTLSAlignment = 8;
@ -196,6 +192,64 @@ static cl::opt<bool> ClCheckConstantShadow("msan-check-constant-shadow",
namespace {
// Memory map parameters used in application-to-shadow address calculation.
// Offset = (Addr & ~AndMask) ^ XorMask
// Shadow = ShadowBase + Offset
// Origin = OriginBase + Offset
struct MemoryMapParams {
uint64_t AndMask;
uint64_t XorMask;
uint64_t ShadowBase;
uint64_t OriginBase;
};
struct PlatformMemoryMapParams {
const MemoryMapParams *bits32;
const MemoryMapParams *bits64;
};
// i386 Linux
static const MemoryMapParams LinuxMemoryMapParams32 = {
0x000080000000, // AndMask
0, // XorMask (not used)
0, // ShadowBase (not used)
0x000040000000, // OriginBase
};
// x86_64 Linux
static const MemoryMapParams LinuxMemoryMapParams64 = {
0x400000000000, // AndMask
0, // XorMask (not used)
0, // ShadowBase (not used)
0x200000000000, // OriginBase
};
// i386 FreeBSD
static const MemoryMapParams FreeBSDMemoryMapParams32 = {
0x000180000000, // AndMask
0x000040000000, // XorMask
0x000020000000, // ShadowBase
0x000700000000, // OriginBase
};
// x86_64 FreeBSD
static const MemoryMapParams FreeBSDMemoryMapParams64 = {
0xc00000000000, // AndMask
0x200000000000, // XorMask
0x100000000000, // ShadowBase
0x380000000000, // OriginBase
};
static const PlatformMemoryMapParams LinuxMemoryMapParams = {
&LinuxMemoryMapParams32,
&LinuxMemoryMapParams64,
};
static const PlatformMemoryMapParams FreeBSDMemoryMapParams = {
&FreeBSDMemoryMapParams32,
&FreeBSDMemoryMapParams64,
};
/// \brief An instrumentation pass implementing detection of uninitialized
/// reads.
///
@ -258,13 +312,9 @@ class MemorySanitizer : public FunctionPass {
/// \brief MSan runtime replacements for memmove, memcpy and memset.
Value *MemmoveFn, *MemcpyFn, *MemsetFn;
/// \brief Address mask used in application-to-shadow address calculation.
/// ShadowAddr is computed as ApplicationAddr & ~ShadowMask.
uint64_t ShadowMask;
/// \brief Offset of the origin shadow from the "normal" shadow.
/// OriginAddr is computed as (ShadowAddr + OriginOffset) & ~3ULL
uint64_t OriginOffset;
/// \brief Branch weights for error reporting.
/// \brief Memory map parameters used in application-to-shadow calculation.
const MemoryMapParams *MapParams;
MDNode *ColdCallWeights;
/// \brief Branch weights for origin store.
MDNode *OriginStoreWeights;
@ -389,16 +439,21 @@ bool MemorySanitizer::doInitialization(Module &M) {
report_fatal_error("data layout missing");
DL = &DLP->getDataLayout();
Triple TargetTriple(M.getTargetTriple());
const PlatformMemoryMapParams *PlatformMapParams;
if (TargetTriple.getOS() == Triple::FreeBSD)
PlatformMapParams = &FreeBSDMemoryMapParams;
else
PlatformMapParams = &LinuxMemoryMapParams;
C = &(M.getContext());
unsigned PtrSize = DL->getPointerSizeInBits(/* AddressSpace */0);
switch (PtrSize) {
case 64:
ShadowMask = kShadowMask64;
OriginOffset = kOriginOffset64;
MapParams = PlatformMapParams->bits64;
break;
case 32:
ShadowMask = kShadowMask32;
OriginOffset = kOriginOffset32;
MapParams = PlatformMapParams->bits32;
break;
default:
report_fatal_error("unsupported pointer size");
@ -724,33 +779,57 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
return IRB.CreateBitCast(V, NoVecTy);
}
/// \brief Compute the integer shadow offset that corresponds to a given
/// application address.
///
/// Offset = (Addr & ~AndMask) ^ XorMask
Value *getShadowPtrOffset(Value *Addr, IRBuilder<> &IRB) {
uint64_t AndMask = MS.MapParams->AndMask;
assert(AndMask != 0 && "AndMask shall be specified");
Value *OffsetLong =
IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
ConstantInt::get(MS.IntptrTy, ~AndMask));
uint64_t XorMask = MS.MapParams->XorMask;
if (XorMask != 0)
OffsetLong = IRB.CreateXor(OffsetLong,
ConstantInt::get(MS.IntptrTy, XorMask));
return OffsetLong;
}
/// \brief Compute the shadow address that corresponds to a given application
/// address.
///
/// Shadow = Addr & ~ShadowMask.
/// Shadow = ShadowBase + Offset
Value *getShadowPtr(Value *Addr, Type *ShadowTy,
IRBuilder<> &IRB) {
Value *ShadowLong =
IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
ConstantInt::get(MS.IntptrTy, ~MS.ShadowMask));
Value *ShadowLong = getShadowPtrOffset(Addr, IRB);
uint64_t ShadowBase = MS.MapParams->ShadowBase;
if (ShadowBase != 0)
ShadowLong =
IRB.CreateAdd(ShadowLong,
ConstantInt::get(MS.IntptrTy, ShadowBase));
return IRB.CreateIntToPtr(ShadowLong, PointerType::get(ShadowTy, 0));
}
/// \brief Compute the origin address that corresponds to a given application
/// address.
///
/// OriginAddr = (ShadowAddr + OriginOffset) & ~3ULL
/// OriginAddr = (OriginBase + Offset) & ~3ULL
Value *getOriginPtr(Value *Addr, IRBuilder<> &IRB, unsigned Alignment) {
Value *ShadowLong =
IRB.CreateAnd(IRB.CreatePointerCast(Addr, MS.IntptrTy),
ConstantInt::get(MS.IntptrTy, ~MS.ShadowMask));
Value *Origin = IRB.CreateAdd(
ShadowLong, ConstantInt::get(MS.IntptrTy, MS.OriginOffset));
Value *OriginLong = getShadowPtrOffset(Addr, IRB);
uint64_t OriginBase = MS.MapParams->OriginBase;
if (OriginBase != 0)
OriginLong =
IRB.CreateAdd(OriginLong,
ConstantInt::get(MS.IntptrTy, OriginBase));
if (Alignment < kMinOriginAlignment) {
uint64_t Mask = kMinOriginAlignment - 1;
Origin = IRB.CreateAnd(Origin, ConstantInt::get(MS.IntptrTy, ~Mask));
OriginLong = IRB.CreateAnd(OriginLong,
ConstantInt::get(MS.IntptrTy, ~Mask));
}
return IRB.CreateIntToPtr(Origin, PointerType::get(IRB.getInt32Ty(), 0));
return IRB.CreateIntToPtr(OriginLong,
PointerType::get(IRB.getInt32Ty(), 0));
}
/// \brief Compute the shadow address for a given function argument.