[hwasan] Detect use after scope within function.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D105201
This commit is contained in:
Florian Mayer 2021-08-02 08:58:49 +01:00
parent 7397dcb403
commit 66b4aafa2e
16 changed files with 489 additions and 116 deletions

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@ -0,0 +1,68 @@
// Tests use-after-scope detection and reporting.
// RUN: %clang_hwasan -mllvm -hwasan-use-after-scope -g %s -o %t && not %run %t 2>&1 | FileCheck %s
// RUN: %clang_hwasan -mllvm -hwasan-use-after-scope -g %s -o %t && not %env_hwasan_opts=symbolize=0 %run %t 2>&1 | FileCheck %s --check-prefix=NOSYM
// RUN: %clang_hwasan -mllvm -hwasan-use-after-scope=false -g %s -o %t && %run %t 2>&1
// Use after scope is turned off by default.
// RUN: %clang_hwasan -g %s -o %t && %run %t 2>&1
// RUN: %clang_hwasan -fexperimental-new-pass-manager -mllvm -hwasan-use-after-scope -g %s -o %t && not %run %t 2>&1 | FileCheck %s
// RUN: %clang_hwasan -fno-experimental-new-pass-manager -mllvm -hwasan-use-after-scope -g %s -o %t && not %run %t 2>&1 | FileCheck %s
// REQUIRES: stable-runtime
// Stack histories currently are not recorded on x86.
// XFAIL: x86_64
void USE(void *x) { // pretend_to_do_something(void *x)
__asm__ __volatile__(""
:
: "r"(x)
: "memory");
}
__attribute__((noinline)) void Unrelated1() {
int A[2];
USE(&A[0]);
}
__attribute__((noinline)) void Unrelated2() {
int BB[3];
USE(&BB[0]);
}
__attribute__((noinline)) void Unrelated3() {
int CCC[4];
USE(&CCC[0]);
}
__attribute__((noinline)) char buggy() {
char *volatile p;
{
char zzz[0x1000];
p = zzz;
}
return *p;
}
int main() {
Unrelated1();
Unrelated2();
Unrelated3();
char p = buggy();
return p;
// CHECK: READ of size 1 at
// CHECK: #0 {{.*}} in buggy{{.*}}stack-uas.c:[[@LINE-10]]
// CHECK: Cause: stack tag-mismatch
// CHECK: is located in stack of thread
// CHECK: Potentially referenced stack objects:
// CHECK-NEXT: zzz in buggy {{.*}}stack-uas.c:[[@LINE-17]]
// CHECK-NEXT: Memory tags around the buggy address
// NOSYM: Previously allocated frames:
// NOSYM-NEXT: record_addr:0x{{.*}} record:0x{{.*}} ({{.*}}/stack-uas.c.tmp+0x{{.*}}){{$}}
// NOSYM-NEXT: record_addr:0x{{.*}} record:0x{{.*}} ({{.*}}/stack-uas.c.tmp+0x{{.*}}){{$}}
// NOSYM-NEXT: record_addr:0x{{.*}} record:0x{{.*}} ({{.*}}/stack-uas.c.tmp+0x{{.*}}){{$}}
// NOSYM-NEXT: record_addr:0x{{.*}} record:0x{{.*}} ({{.*}}/stack-uas.c.tmp+0x{{.*}}){{$}}
// NOSYM-NEXT: Memory tags around the buggy address
// CHECK: SUMMARY: HWAddressSanitizer: tag-mismatch {{.*}} in buggy
}

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@ -1,8 +1,8 @@
// RUN: %clangxx_asan %stdcxx11 -O1 -fsanitize-address-use-after-scope %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan
// XFAIL: *
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope --std=c++11 -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
// REQUIRES: aarch64-target-arch
#include <functional>
@ -12,8 +12,9 @@ int main() {
int x = 0;
f = [&x]() __attribute__((noinline)) {
return x; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in {{.*}}use-after-scope-capture.cpp:[[@LINE-2]]
// CHECK: Cause: stack tag-mismatch
};
}
return f(); // BOOM

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
#include <stdio.h>
@ -10,7 +12,7 @@ struct IntHolder {
explicit IntHolder(int *val = 0) : val_(val) {}
__attribute__((noinline)) ~IntHolder() {
printf("Value: %d\n", *val_); // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in IntHolder::~IntHolder{{.*}}.cpp:[[@LINE-2]]
}
void set(int *val) { val_ = val; }

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@ -1,10 +1,12 @@
// RUN: %clangxx_asan -O0 -fsanitize-address-use-after-scope %s -o %t && %run %t
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O0 %s -o %t && %run %t
// Function jumps over variable initialization making lifetime analysis
// ambiguous. Asan should ignore such variable and program must not fail.
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
#include <stdlib.h>

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
int *p;
bool b = true;
@ -13,6 +15,7 @@ int main() {
p = x + 1;
}
return *p; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}.cpp:[[@LINE-2]]
// CHECK: Cause: stack tag-mismatch
}

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@ -1,15 +1,16 @@
// This is the ASAN test of the same name ported to HWAsan.
// Test with "-O2" only to make sure inlining (leading to use-after-scope)
// happens. "always_inline" is not enough, as Clang doesn't emit
// llvm.lifetime intrinsics at -O0.
//
// RUN: %clangxx_asan -O2 -fsanitize-address-use-after-scope %s -o %t && \
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O2 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
int *arr;
__attribute__((always_inline)) void inlined(int arg) {
int x[5];
for (int i = 0; i < arg; i++)
@ -20,12 +21,6 @@ __attribute__((always_inline)) void inlined(int arg) {
int main(int argc, char *argv[]) {
inlined(argc);
return arr[argc - 1]; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: READ of size 4 at 0x{{.*}} thread T0
// CHECK: #0 0x{{.*}} in main
// CHECK: {{.*}}use-after-scope-inlined.cpp:[[@LINE-4]]
// CHECK: Address 0x{{.*}} is located in stack of thread T0 at offset [[OFFSET:[^ ]*]] in frame
// CHECK: {{.*}} in main
// CHECK: This frame has
// CHECK: {{\[}}[[OFFSET]], {{.*}}) 'x.i' (line [[@LINE-15]])
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: Cause: stack tag-mismatch
}

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
volatile int *p;
@ -13,8 +15,7 @@ int main() {
p = x + i;
}
return *p; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}use-after-scope-loop-bug.cpp:[[@LINE-2]]
// CHECK: Address 0x{{.*}} is located in stack of thread T{{.*}} at offset [[OFFSET:[^ ]+]] in frame
// {{\[}}[[OFFSET]], {{[0-9]+}}) 'x'
// CHECK: Cause: stack tag-mismatch
}

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
#include <stdlib.h>
@ -14,8 +16,7 @@ int main() {
p = &x;
}
return *p; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}use-after-scope-loop-removed.cpp:[[@LINE-2]]
// CHECK: Address 0x{{.*}} is located in stack of thread T{{.*}} at offset [[OFFSET:[^ ]+]] in frame
// {{\[}}[[OFFSET]], {{[0-9]+}}) 'x'
// CHECK: Cause: stack tag-mismatch
}

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
int *p[3];
@ -12,6 +14,7 @@ int main() {
p[i] = &x;
}
return **p; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}.cpp:[[@LINE-2]]
// CHECK: Cause: stack tag-mismatch
}

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@ -1,7 +1,9 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && %run %t
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && %run %t
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
#include <stdio.h>
#include <stdlib.h>

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan %stdcxx11 -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -std=c++11 -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
struct IntHolder {
int val;
@ -17,7 +19,8 @@ __attribute__((noinline)) void save(const IntHolder &holder) {
int main(int argc, char *argv[]) {
save({argc});
int x = saved->val; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}use-after-scope-temp.cpp:[[@LINE-2]]
// CHECK: Cause: stack tag-mismatch
return x;
}

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@ -1,8 +1,10 @@
// RUN: %clangxx_asan %stdcxx11 -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -std=c++11 -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
struct IntHolder {
__attribute__((noinline)) const IntHolder &Self() const {
@ -16,7 +18,8 @@ const IntHolder *saved;
int main(int argc, char *argv[]) {
saved = &IntHolder().Self();
int x = saved->val; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}use-after-scope-temp2.cpp:[[@LINE-2]]
// CHECK: Cause: stack tag-mismatch
return x;
}

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@ -1,18 +1,21 @@
// RUN: %clangxx_asan %stdcxx11 -O0 -fsanitize-address-use-after-scope %s -o %t
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -std=c++11 -O0 %s -o %t
// RUN: not %run %t 0 2>&1 | FileCheck %s
// RUN: not %run %t 1 2>&1 | FileCheck %s
// RUN: not %run %t 2 2>&1 | FileCheck %s
// RUN: not %run %t 3 2>&1 | FileCheck %s
// RUN: not %run %t 4 2>&1 | FileCheck %s
// RUN: not %run %t 5 2>&1 | FileCheck %s
// RUN: not %run %t 6 2>&1 | FileCheck %s
// The std::vector case is broken because of limited lifetime tracking.
// TODO(fmayer): Fix and enable.
// RUN: not %run %t 7 2>&1 | FileCheck %s
// RUN: not %run %t 8 2>&1 | FileCheck %s
// RUN: not %run %t 9 2>&1 | FileCheck %s
// RUN: not %run %t 10 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
#include <stdlib.h>
#include <string>
@ -46,10 +49,9 @@ __attribute__((noinline)) void test() {
}
ptr.Access();
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #{{[0-9]+}} 0x{{.*}} in {{(void )?test.*\((void)?\) .*}}use-after-scope-types.cpp
// CHECK: Address 0x{{.*}} is located in stack of thread T{{.*}} at offset [[OFFSET:[^ ]+]] in frame
// {{\[}}[[OFFSET]], {{[0-9]+}}) 'x'
// CHECK: Cause: stack tag-mismatch
}
int main(int argc, char **argv) {

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@ -1,12 +1,10 @@
// RUN: %clangxx_asan -O1 -fsanitize-address-use-after-scope %s -o %t && \
// This is the ASAN test of the same name ported to HWAsan.
// RUN: %clangxx_hwasan -mllvm -hwasan-use-after-scope -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
// -fsanitize-address-use-after-scope is now on by default:
// RUN: %clangxx_asan -O1 %s -o %t && \
// RUN: not %run %t 2>&1 | FileCheck %s
//
// Not expected to work yet with HWAsan.
// XFAIL: *
// REQUIRES: aarch64-target-arch
// REQUIRES: stable-runtime
volatile int *p = 0;
@ -16,9 +14,8 @@ int main() {
p = &x;
}
*p = 5; // BOOM
// CHECK: ERROR: AddressSanitizer: stack-use-after-scope
// CHECK: ERROR: HWAddressSanitizer: tag-mismatch
// CHECK: #0 0x{{.*}} in main {{.*}}use-after-scope.cpp:[[@LINE-2]]
// CHECK: Address 0x{{.*}} is located in stack of thread T{{.*}} at offset [[OFFSET:[^ ]+]] in frame
// {{\[}}[[OFFSET]], {{[0-9]+}}) 'x'
// CHECK: Cause: stack tag-mismatch
return 0;
}

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@ -17,7 +17,9 @@
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Analysis/PostDominators.h"
#include "llvm/Analysis/StackSafetyAnalysis.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
@ -26,6 +28,7 @@
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InlineAsm.h"
@ -41,6 +44,7 @@
#include "llvm/IR/Value.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
#include "llvm/PassRegistry.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
@ -115,6 +119,11 @@ static cl::opt<bool>
cl::Hidden, cl::desc("Use Stack Safety analysis results"),
cl::Optional);
static cl::opt<bool>
ClUseAfterScope("hwasan-use-after-scope",
cl::desc("detect use after scope within function"),
cl::Hidden, cl::init(false));
static cl::opt<bool> ClUARRetagToZero(
"hwasan-uar-retag-to-zero",
cl::desc("Clear alloca tags before returning from the function to allow "
@ -220,9 +229,21 @@ bool shouldUseStackSafetyAnalysis(const Triple &TargetTriple,
return shouldInstrumentStack(TargetTriple) &&
mightUseStackSafetyAnalysis(DisableOptimization);
}
bool shouldDetectUseAfterScope(const Triple &TargetTriple) {
return ClUseAfterScope && shouldInstrumentStack(TargetTriple);
}
/// An instrumentation pass implementing detection of addressability bugs
/// using tagged pointers.
class HWAddressSanitizer {
private:
struct AllocaInfo {
AllocaInst *AI;
SmallVector<IntrinsicInst *, 2> LifetimeStart;
SmallVector<IntrinsicInst *, 2> LifetimeEnd;
};
public:
HWAddressSanitizer(Module &M, bool CompileKernel, bool Recover,
const StackSafetyGlobalInfo *SSI)
@ -237,7 +258,9 @@ public:
void setSSI(const StackSafetyGlobalInfo *S) { SSI = S; }
bool sanitizeFunction(Function &F);
bool sanitizeFunction(Function &F,
llvm::function_ref<const DominatorTree &()> GetDT,
llvm::function_ref<const PostDominatorTree &()> GetPDT);
void initializeModule();
void createHwasanCtorComdat();
@ -260,13 +283,16 @@ public:
Instruction *I, SmallVectorImpl<InterestingMemoryOperand> &Interesting);
bool isInterestingAlloca(const AllocaInst &AI);
bool tagAlloca(IRBuilder<> &IRB, AllocaInst *AI, Value *Tag, size_t Size);
void tagAlloca(IRBuilder<> &IRB, AllocaInst *AI, Value *Tag, size_t Size);
Value *tagPointer(IRBuilder<> &IRB, Type *Ty, Value *PtrLong, Value *Tag);
Value *untagPointer(IRBuilder<> &IRB, Value *PtrLong);
bool instrumentStack(
SmallVectorImpl<AllocaInst *> &Allocas,
MapVector<AllocaInst *, AllocaInfo> &AllocasToInstrument,
SmallVector<Instruction *, 4> &UnrecognizedLifetimes,
DenseMap<AllocaInst *, std::vector<DbgVariableIntrinsic *>> &AllocaDbgMap,
SmallVectorImpl<Instruction *> &RetVec, Value *StackTag);
SmallVectorImpl<Instruction *> &RetVec, Value *StackTag,
llvm::function_ref<const DominatorTree &()> GetDT,
llvm::function_ref<const PostDominatorTree &()> GetPDT);
Value *readRegister(IRBuilder<> &IRB, StringRef Name);
bool instrumentLandingPads(SmallVectorImpl<Instruction *> &RetVec);
Value *getNextTagWithCall(IRBuilder<> &IRB);
@ -315,6 +341,7 @@ private:
void init(Triple &TargetTriple, bool InstrumentWithCalls);
unsigned getObjectAlignment() const { return 1U << Scale; }
};
ShadowMapping Mapping;
Type *VoidTy = Type::getVoidTy(M.getContext());
@ -331,6 +358,7 @@ private:
bool InstrumentLandingPads;
bool InstrumentWithCalls;
bool InstrumentStack;
bool DetectUseAfterScope;
bool UsePageAliases;
bool HasMatchAllTag = false;
@ -377,14 +405,21 @@ public:
}
bool runOnFunction(Function &F) override {
if (shouldUseStackSafetyAnalysis(Triple(F.getParent()->getTargetTriple()),
DisableOptimization)) {
auto TargetTriple = Triple(F.getParent()->getTargetTriple());
if (shouldUseStackSafetyAnalysis(TargetTriple, DisableOptimization)) {
// We cannot call getAnalysis in doInitialization, that would cause a
// crash as the required analyses are not initialized yet.
HWASan->setSSI(
&getAnalysis<StackSafetyGlobalInfoWrapperPass>().getResult());
}
return HWASan->sanitizeFunction(F);
return HWASan->sanitizeFunction(
F,
[&]() -> const DominatorTree & {
return getAnalysis<DominatorTreeWrapperPass>().getDomTree();
},
[&]() -> const PostDominatorTree & {
return getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree();
});
}
bool doFinalization(Module &M) override {
@ -399,6 +434,8 @@ public:
// This is so we don't need to plumb TargetTriple all the way to here.
if (mightUseStackSafetyAnalysis(DisableOptimization))
AU.addRequired<StackSafetyGlobalInfoWrapperPass>();
AU.addRequired<DominatorTreeWrapperPass>();
AU.addRequired<PostDominatorTreeWrapperPass>();
}
private:
@ -417,6 +454,8 @@ INITIALIZE_PASS_BEGIN(
"HWAddressSanitizer: detect memory bugs using tagged addressing.", false,
false)
INITIALIZE_PASS_DEPENDENCY(StackSafetyGlobalInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
INITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass)
INITIALIZE_PASS_END(
HWAddressSanitizerLegacyPass, "hwasan",
"HWAddressSanitizer: detect memory bugs using tagged addressing.", false,
@ -438,13 +477,23 @@ HWAddressSanitizerPass::HWAddressSanitizerPass(bool CompileKernel, bool Recover,
PreservedAnalyses HWAddressSanitizerPass::run(Module &M,
ModuleAnalysisManager &MAM) {
const StackSafetyGlobalInfo *SSI = nullptr;
if (shouldUseStackSafetyAnalysis(llvm::Triple(M.getTargetTriple()),
DisableOptimization))
auto TargetTriple = llvm::Triple(M.getTargetTriple());
if (shouldUseStackSafetyAnalysis(TargetTriple, DisableOptimization))
SSI = &MAM.getResult<StackSafetyGlobalAnalysis>(M);
HWAddressSanitizer HWASan(M, CompileKernel, Recover, SSI);
bool Modified = false;
for (Function &F : M)
Modified |= HWASan.sanitizeFunction(F);
auto &FAM = MAM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
for (Function &F : M) {
Modified |= HWASan.sanitizeFunction(
F,
[&]() -> const DominatorTree & {
return FAM.getResult<DominatorTreeAnalysis>(F);
},
[&]() -> const PostDominatorTree & {
return FAM.getResult<PostDominatorTreeAnalysis>(F);
});
}
if (Modified)
return PreservedAnalyses::none();
return PreservedAnalyses::all();
@ -566,6 +615,7 @@ void HWAddressSanitizer::initializeModule() {
UsePageAliases = shouldUsePageAliases(TargetTriple);
InstrumentWithCalls = shouldInstrumentWithCalls(TargetTriple);
InstrumentStack = shouldInstrumentStack(TargetTriple);
DetectUseAfterScope = shouldDetectUseAfterScope(TargetTriple);
PointerTagShift = IsX86_64 ? 57 : 56;
TagMaskByte = IsX86_64 ? 0x3F : 0xFF;
@ -968,7 +1018,7 @@ static uint64_t getAllocaSizeInBytes(const AllocaInst &AI) {
return SizeInBytes * ArraySize;
}
bool HWAddressSanitizer::tagAlloca(IRBuilder<> &IRB, AllocaInst *AI, Value *Tag,
void HWAddressSanitizer::tagAlloca(IRBuilder<> &IRB, AllocaInst *AI, Value *Tag,
size_t Size) {
size_t AlignedSize = alignTo(Size, Mapping.getObjectAlignment());
if (!UseShortGranules)
@ -999,7 +1049,6 @@ bool HWAddressSanitizer::tagAlloca(IRBuilder<> &IRB, AllocaInst *AI, Value *Tag,
AlignedSize - 1));
}
}
return true;
}
unsigned HWAddressSanitizer::retagMask(unsigned AllocaNo) {
@ -1232,16 +1281,23 @@ bool HWAddressSanitizer::instrumentLandingPads(
}
bool HWAddressSanitizer::instrumentStack(
SmallVectorImpl<AllocaInst *> &Allocas,
MapVector<AllocaInst *, AllocaInfo> &AllocasToInstrument,
SmallVector<Instruction *, 4> &UnrecognizedLifetimes,
DenseMap<AllocaInst *, std::vector<DbgVariableIntrinsic *>> &AllocaDbgMap,
SmallVectorImpl<Instruction *> &RetVec, Value *StackTag) {
SmallVectorImpl<Instruction *> &RetVec, Value *StackTag,
llvm::function_ref<const DominatorTree &()> GetDT,
llvm::function_ref<const PostDominatorTree &()> GetPDT) {
// Ideally, we want to calculate tagged stack base pointer, and rewrite all
// alloca addresses using that. Unfortunately, offsets are not known yet
// (unless we use ASan-style mega-alloca). Instead we keep the base tag in a
// temp, shift-OR it into each alloca address and xor with the retag mask.
// This generates one extra instruction per alloca use.
for (unsigned N = 0; N < Allocas.size(); ++N) {
auto *AI = Allocas[N];
unsigned int I = 0;
for (auto &KV : AllocasToInstrument) {
auto N = I++;
auto *AI = KV.first;
AllocaInfo &Info = KV.second;
IRBuilder<> IRB(AI->getNextNode());
// Replace uses of the alloca with tagged address.
@ -1268,17 +1324,39 @@ bool HWAddressSanitizer::instrumentStack(
}
size_t Size = getAllocaSizeInBytes(*AI);
tagAlloca(IRB, AI, Tag, Size);
for (auto RI : RetVec) {
IRB.SetInsertPoint(RI);
// Re-tag alloca memory with the special UAR tag.
Value *Tag = getUARTag(IRB, StackTag);
tagAlloca(IRB, AI, Tag, alignTo(Size, Mapping.getObjectAlignment()));
size_t AlignedSize = alignTo(Size, Mapping.getObjectAlignment());
bool StandardLifetime = UnrecognizedLifetimes.empty() &&
Info.LifetimeStart.size() == 1 &&
Info.LifetimeEnd.size() == 1;
if (DetectUseAfterScope && StandardLifetime) {
IntrinsicInst *Start = Info.LifetimeStart[0];
IntrinsicInst *End = Info.LifetimeEnd[0];
IRB.SetInsertPoint(Start->getNextNode());
auto TagEnd = [&](Instruction *Node) {
IRB.SetInsertPoint(Node);
Value *UARTag = getUARTag(IRB, StackTag);
tagAlloca(IRB, AI, UARTag, AlignedSize);
};
tagAlloca(IRB, AI, Tag, Size);
if (!forAllReachableExits(GetDT(), GetPDT(), Start, End, RetVec, TagEnd))
End->eraseFromParent();
} else {
tagAlloca(IRB, AI, Tag, Size);
for (auto *RI : RetVec) {
IRB.SetInsertPoint(RI);
Value *UARTag = getUARTag(IRB, StackTag);
tagAlloca(IRB, AI, UARTag, AlignedSize);
}
if (!StandardLifetime) {
for (auto &II : Info.LifetimeStart)
II->eraseFromParent();
for (auto &II : Info.LifetimeEnd)
II->eraseFromParent();
}
}
}
for (auto &I : UnrecognizedLifetimes)
I->eraseFromParent();
return true;
}
@ -1300,7 +1378,9 @@ bool HWAddressSanitizer::isInterestingAlloca(const AllocaInst &AI) {
!(SSI && SSI->isSafe(AI));
}
bool HWAddressSanitizer::sanitizeFunction(Function &F) {
bool HWAddressSanitizer::sanitizeFunction(
Function &F, llvm::function_ref<const DominatorTree &()> GetDT,
llvm::function_ref<const PostDominatorTree &()> GetPDT) {
if (&F == HwasanCtorFunction)
return false;
@ -1311,18 +1391,36 @@ bool HWAddressSanitizer::sanitizeFunction(Function &F) {
SmallVector<InterestingMemoryOperand, 16> OperandsToInstrument;
SmallVector<MemIntrinsic *, 16> IntrinToInstrument;
SmallVector<AllocaInst *, 8> AllocasToInstrument;
MapVector<AllocaInst *, AllocaInfo> AllocasToInstrument;
SmallVector<Instruction *, 8> RetVec;
SmallVector<Instruction *, 8> LandingPadVec;
SmallVector<Instruction *, 4> UnrecognizedLifetimes;
DenseMap<AllocaInst *, std::vector<DbgVariableIntrinsic *>> AllocaDbgMap;
for (auto &BB : F) {
for (auto &Inst : BB) {
if (InstrumentStack)
if (InstrumentStack) {
if (AllocaInst *AI = dyn_cast<AllocaInst>(&Inst)) {
if (isInterestingAlloca(*AI))
AllocasToInstrument.push_back(AI);
AllocasToInstrument.insert({AI, {}});
continue;
}
auto *II = dyn_cast<IntrinsicInst>(&Inst);
if (II && (II->getIntrinsicID() == Intrinsic::lifetime_start ||
II->getIntrinsicID() == Intrinsic::lifetime_end)) {
AllocaInst *AI = findAllocaForValue(II->getArgOperand(1));
if (!AI) {
UnrecognizedLifetimes.push_back(&Inst);
continue;
}
if (!isInterestingAlloca(*AI))
continue;
if (II->getIntrinsicID() == Intrinsic::lifetime_start)
AllocasToInstrument[AI].LifetimeStart.push_back(II);
else
AllocasToInstrument[AI].LifetimeEnd.push_back(II);
continue;
}
}
if (isa<ReturnInst>(Inst) || isa<ResumeInst>(Inst) ||
isa<CleanupReturnInst>(Inst))
@ -1377,13 +1475,15 @@ bool HWAddressSanitizer::sanitizeFunction(Function &F) {
if (!AllocasToInstrument.empty()) {
Value *StackTag =
ClGenerateTagsWithCalls ? nullptr : getStackBaseTag(EntryIRB);
instrumentStack(AllocasToInstrument, AllocaDbgMap, RetVec, StackTag);
instrumentStack(AllocasToInstrument, UnrecognizedLifetimes, AllocaDbgMap,
RetVec, StackTag, GetDT, GetPDT);
}
// Pad and align each of the allocas that we instrumented to stop small
// uninteresting allocas from hiding in instrumented alloca's padding and so
// that we have enough space to store real tags for short granules.
DenseMap<AllocaInst *, AllocaInst *> AllocaToPaddedAllocaMap;
for (AllocaInst *AI : AllocasToInstrument) {
for (auto &KV : AllocasToInstrument) {
AllocaInst *AI = KV.first;
uint64_t Size = getAllocaSizeInBytes(*AI);
uint64_t AlignedSize = alignTo(Size, Mapping.getObjectAlignment());
AI->setAlignment(

View File

@ -0,0 +1,190 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -hwasan -hwasan-use-after-scope=1 -hwasan-generate-tags-with-calls -S < %s | FileCheck %s --check-prefixes=SCOPE
; RUN: opt -hwasan -hwasan-use-after-scope=0 -hwasan-generate-tags-with-calls -S < %s | FileCheck %s --check-prefixes=NOSCOPE
; ModuleID = 'use-after-scope.c'
source_filename = "use-after-scope.c"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
define dso_local i32 @standard_lifetime() local_unnamed_addr sanitize_hwaddress {
; SCOPE-LABEL: @standard_lifetime(
; SCOPE-NEXT: [[DOTHWASAN_SHADOW:%.*]] = call i8* asm "", "=r,0"(i8* null)
; SCOPE-NEXT: [[TMP1:%.*]] = alloca { i8, [15 x i8] }, align 16
; SCOPE-NEXT: [[TMP2:%.*]] = bitcast { i8, [15 x i8] }* [[TMP1]] to i8*
; SCOPE-NEXT: [[TMP3:%.*]] = call i8 @__hwasan_generate_tag()
; SCOPE-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i64
; SCOPE-NEXT: [[TMP5:%.*]] = ptrtoint i8* [[TMP2]] to i64
; SCOPE-NEXT: [[TMP6:%.*]] = shl i64 [[TMP4]], 57
; SCOPE-NEXT: [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
; SCOPE-NEXT: [[ALLOCA_0_HWASAN:%.*]] = inttoptr i64 [[TMP7]] to i8*
; SCOPE-NEXT: br label [[TMP8:%.*]]
; SCOPE: 8:
; SCOPE-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: [[TMP9:%.*]] = trunc i64 [[TMP4]] to i8
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 [[TMP9]], i64 16)
; SCOPE-NEXT: [[TMP10:%.*]] = tail call i1 (...) @cond()
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; SCOPE-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: br i1 [[TMP10]], label [[TMP11:%.*]], label [[TMP8]]
; SCOPE: 11:
; SCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: ret i32 0
;
; NOSCOPE-LABEL: @standard_lifetime(
; NOSCOPE-NEXT: [[DOTHWASAN_SHADOW:%.*]] = call i8* asm "", "=r,0"(i8* null)
; NOSCOPE-NEXT: [[TMP1:%.*]] = alloca { i8, [15 x i8] }, align 16
; NOSCOPE-NEXT: [[TMP2:%.*]] = bitcast { i8, [15 x i8] }* [[TMP1]] to i8*
; NOSCOPE-NEXT: [[TMP3:%.*]] = call i8 @__hwasan_generate_tag()
; NOSCOPE-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i64
; NOSCOPE-NEXT: [[TMP5:%.*]] = ptrtoint i8* [[TMP2]] to i64
; NOSCOPE-NEXT: [[TMP6:%.*]] = shl i64 [[TMP4]], 57
; NOSCOPE-NEXT: [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
; NOSCOPE-NEXT: [[ALLOCA_0_HWASAN:%.*]] = inttoptr i64 [[TMP7]] to i8*
; NOSCOPE-NEXT: [[TMP8:%.*]] = trunc i64 [[TMP4]] to i8
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 [[TMP8]], i64 16)
; NOSCOPE-NEXT: br label [[TMP9:%.*]]
; NOSCOPE: 9:
; NOSCOPE-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: [[TMP10:%.*]] = tail call i1 (...) @cond()
; NOSCOPE-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: br i1 [[TMP10]], label [[TMP11:%.*]], label [[TMP9]]
; NOSCOPE: 11:
; NOSCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; NOSCOPE-NEXT: ret i32 0
;
%1 = alloca i8, align 1
br label %2
2: ; preds = %2, %0
; We should tag the memory after the br (in the loop).
call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %1)
%3 = tail call i1 (...) @cond() #2
; We should tag the memory before the next br (before the jump back).
call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull %1)
br i1 %3, label %4, label %2
4: ; preds = %2
call void @use(i8* nonnull %1) #2
ret i32 0
}
define dso_local i32 @multiple_lifetimes() local_unnamed_addr sanitize_hwaddress {
; SCOPE-LABEL: @multiple_lifetimes(
; SCOPE-NEXT: [[DOTHWASAN_SHADOW:%.*]] = call i8* asm "", "=r,0"(i8* null)
; SCOPE-NEXT: [[TMP1:%.*]] = alloca { i8, [15 x i8] }, align 16
; SCOPE-NEXT: [[TMP2:%.*]] = bitcast { i8, [15 x i8] }* [[TMP1]] to i8*
; SCOPE-NEXT: [[TMP3:%.*]] = call i8 @__hwasan_generate_tag()
; SCOPE-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i64
; SCOPE-NEXT: [[TMP5:%.*]] = ptrtoint i8* [[TMP2]] to i64
; SCOPE-NEXT: [[TMP6:%.*]] = shl i64 [[TMP4]], 57
; SCOPE-NEXT: [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
; SCOPE-NEXT: [[ALLOCA_0_HWASAN:%.*]] = inttoptr i64 [[TMP7]] to i8*
; SCOPE-NEXT: [[TMP8:%.*]] = trunc i64 [[TMP4]] to i8
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 [[TMP8]], i64 16)
; SCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; SCOPE-NEXT: ret i32 0
;
; NOSCOPE-LABEL: @multiple_lifetimes(
; NOSCOPE-NEXT: [[DOTHWASAN_SHADOW:%.*]] = call i8* asm "", "=r,0"(i8* null)
; NOSCOPE-NEXT: [[TMP1:%.*]] = alloca { i8, [15 x i8] }, align 16
; NOSCOPE-NEXT: [[TMP2:%.*]] = bitcast { i8, [15 x i8] }* [[TMP1]] to i8*
; NOSCOPE-NEXT: [[TMP3:%.*]] = call i8 @__hwasan_generate_tag()
; NOSCOPE-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i64
; NOSCOPE-NEXT: [[TMP5:%.*]] = ptrtoint i8* [[TMP2]] to i64
; NOSCOPE-NEXT: [[TMP6:%.*]] = shl i64 [[TMP4]], 57
; NOSCOPE-NEXT: [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
; NOSCOPE-NEXT: [[ALLOCA_0_HWASAN:%.*]] = inttoptr i64 [[TMP7]] to i8*
; NOSCOPE-NEXT: [[TMP8:%.*]] = trunc i64 [[TMP4]] to i8
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 [[TMP8]], i64 16)
; NOSCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; NOSCOPE-NEXT: ret i32 0
;
%1 = alloca i8, align 1
; We erase lifetime markers if we insert instrumentation outside of the
; lifetime.
call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %1)
call void @use(i8* nonnull %1) #2
call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull %1)
call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %1)
call void @use(i8* nonnull %1) #2
call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull %1)
ret i32 0
}
define dso_local i32 @unreachable_exit() local_unnamed_addr sanitize_hwaddress {
; SCOPE-LABEL: @unreachable_exit(
; SCOPE-NEXT: [[DOTHWASAN_SHADOW:%.*]] = call i8* asm "", "=r,0"(i8* null)
; SCOPE-NEXT: [[TMP1:%.*]] = alloca { i8, [15 x i8] }, align 16
; SCOPE-NEXT: [[TMP2:%.*]] = bitcast { i8, [15 x i8] }* [[TMP1]] to i8*
; SCOPE-NEXT: [[TMP3:%.*]] = call i8 @__hwasan_generate_tag()
; SCOPE-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i64
; SCOPE-NEXT: [[TMP5:%.*]] = ptrtoint i8* [[TMP2]] to i64
; SCOPE-NEXT: [[TMP6:%.*]] = shl i64 [[TMP4]], 57
; SCOPE-NEXT: [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
; SCOPE-NEXT: [[ALLOCA_0_HWASAN:%.*]] = inttoptr i64 [[TMP7]] to i8*
; SCOPE-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: [[TMP8:%.*]] = trunc i64 [[TMP4]] to i8
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 [[TMP8]], i64 16)
; SCOPE-NEXT: [[TMP9:%.*]] = tail call i1 (...) @cond()
; SCOPE-NEXT: br i1 [[TMP9]], label [[TMP10:%.*]], label [[TMP11:%.*]]
; SCOPE: 10:
; SCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; SCOPE-NEXT: ret i32 0
; SCOPE: 11:
; SCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; SCOPE-NEXT: ret i32 0
;
; NOSCOPE-LABEL: @unreachable_exit(
; NOSCOPE-NEXT: [[DOTHWASAN_SHADOW:%.*]] = call i8* asm "", "=r,0"(i8* null)
; NOSCOPE-NEXT: [[TMP1:%.*]] = alloca { i8, [15 x i8] }, align 16
; NOSCOPE-NEXT: [[TMP2:%.*]] = bitcast { i8, [15 x i8] }* [[TMP1]] to i8*
; NOSCOPE-NEXT: [[TMP3:%.*]] = call i8 @__hwasan_generate_tag()
; NOSCOPE-NEXT: [[TMP4:%.*]] = zext i8 [[TMP3]] to i64
; NOSCOPE-NEXT: [[TMP5:%.*]] = ptrtoint i8* [[TMP2]] to i64
; NOSCOPE-NEXT: [[TMP6:%.*]] = shl i64 [[TMP4]], 57
; NOSCOPE-NEXT: [[TMP7:%.*]] = or i64 [[TMP5]], [[TMP6]]
; NOSCOPE-NEXT: [[ALLOCA_0_HWASAN:%.*]] = inttoptr i64 [[TMP7]] to i8*
; NOSCOPE-NEXT: [[TMP8:%.*]] = trunc i64 [[TMP4]] to i8
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 [[TMP8]], i64 16)
; NOSCOPE-NEXT: call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: [[TMP9:%.*]] = tail call i1 (...) @cond()
; NOSCOPE-NEXT: br i1 [[TMP9]], label [[TMP10:%.*]], label [[TMP11:%.*]]
; NOSCOPE: 10:
; NOSCOPE-NEXT: call void @use(i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull [[ALLOCA_0_HWASAN]])
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; NOSCOPE-NEXT: ret i32 0
; NOSCOPE: 11:
; NOSCOPE-NEXT: call void @__hwasan_tag_memory(i8* [[TMP2]], i8 0, i64 16)
; NOSCOPE-NEXT: ret i32 0
;
%1 = alloca i8, align 1
call void @llvm.lifetime.start.p0i8(i64 1, i8* nonnull %1)
%2 = tail call i1 (...) @cond() #2
br i1 %2, label %3, label %4
3:
call void @use(i8* nonnull %1) #2
call void @llvm.lifetime.end.p0i8(i64 1, i8* nonnull %1)
ret i32 0
4:
ret i32 0
}
declare dso_local i1 @cond(...) local_unnamed_addr
declare dso_local void @use(i8*) local_unnamed_addr
; Function Attrs: argmemonly mustprogress nofree nosync nounwind willreturn
declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)
; Function Attrs: argmemonly mustprogress nofree nosync nounwind willreturn
declare void @llvm.lifetime.end.p0i8(i64 immarg, i8* nocapture)