[compiler-rt] [llvm] [ASan][compiler-rt] Implemented Dormant Mode in ASan (PR #99857)

via llvm-commits llvm-commits at lists.llvm.org
Thu Aug 8 02:49:22 PDT 2024


https://github.com/gbMattN updated https://github.com/llvm/llvm-project/pull/99857

>From 992d2cb9dc349ce83ba9cc07212efef38ec88189 Mon Sep 17 00:00:00 2001
From: Matthew Nagy <gbmatt at tiger-linux2.domain.snsys.com>
Date: Mon, 22 Jul 2024 10:13:51 +0000
Subject: [PATCH 1/3] [ASan][compiler-rt] Implemented Dormant Mode in ASan

---
 .../include/sanitizer/asan_interface.h        |  7 +++
 compiler-rt/lib/asan/asan_interface.inc       |  1 +
 .../lib/asan/asan_interface_internal.h        |  6 +++
 compiler-rt/lib/asan/asan_rtl.cpp             |  3 ++
 .../Instrumentation/AddressSanitizer.cpp      | 48 +++++++++++++++++--
 5 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/compiler-rt/include/sanitizer/asan_interface.h b/compiler-rt/include/sanitizer/asan_interface.h
index 37b6d08f4db19..f6ca4acb03e9d 100644
--- a/compiler-rt/include/sanitizer/asan_interface.h
+++ b/compiler-rt/include/sanitizer/asan_interface.h
@@ -269,6 +269,13 @@ void SANITIZER_CDECL __asan_set_death_callback(void (*callback)(void));
 void SANITIZER_CDECL
 __asan_set_error_report_callback(void (*callback)(const char *));
 
+/// Sets whether ASan should be dormant or not. If 0 is passed, ASan resumes
+/// checking memory accesses for errors. If a non-0 value is passed, these
+/// checks will be skipped.
+///
+/// \param dormancy A boolean to control if ASan is dormant or not.
+void SANITIZER_CDECL __asan_set_dormant(int dormancy);
+
 /// User-provided callback on ASan errors.
 ///
 /// You can provide a function that would be called immediately when ASan
diff --git a/compiler-rt/lib/asan/asan_interface.inc b/compiler-rt/lib/asan/asan_interface.inc
index bfc44b4619623..499014fcc4a49 100644
--- a/compiler-rt/lib/asan/asan_interface.inc
+++ b/compiler-rt/lib/asan/asan_interface.inc
@@ -107,6 +107,7 @@ INTERFACE_FUNCTION(__asan_report_store16_noabort)
 INTERFACE_FUNCTION(__asan_report_store_n_noabort)
 INTERFACE_FUNCTION(__asan_set_death_callback)
 INTERFACE_FUNCTION(__asan_set_error_report_callback)
+INTERFACE_FUNCTION(__asan_set_dormant)
 INTERFACE_FUNCTION(__asan_set_shadow_00)
 INTERFACE_FUNCTION(__asan_set_shadow_01)
 INTERFACE_FUNCTION(__asan_set_shadow_02)
diff --git a/compiler-rt/lib/asan/asan_interface_internal.h b/compiler-rt/lib/asan/asan_interface_internal.h
index a998263780221..9b2752ce7e05b 100644
--- a/compiler-rt/lib/asan/asan_interface_internal.h
+++ b/compiler-rt/lib/asan/asan_interface_internal.h
@@ -184,6 +184,9 @@ extern "C" {
   SANITIZER_INTERFACE_ATTRIBUTE
   void __asan_set_error_report_callback(void (*callback)(const char*));
 
+  SANITIZER_INTERFACE_ATTRIBUTE
+  void __asan_set_dormant(int dormancy);
+
   SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
   void __asan_on_error();
 
@@ -202,6 +205,9 @@ extern "C" {
   SANITIZER_INTERFACE_ATTRIBUTE
   extern uptr *__asan_test_only_reported_buggy_pointer;
 
+  SANITIZER_INTERFACE_ATTRIBUTE
+  extern bool __asan_is_dormant;
+
   SANITIZER_INTERFACE_ATTRIBUTE void __asan_load1(uptr p);
   SANITIZER_INTERFACE_ATTRIBUTE void __asan_load2(uptr p);
   SANITIZER_INTERFACE_ATTRIBUTE void __asan_load4(uptr p);
diff --git a/compiler-rt/lib/asan/asan_rtl.cpp b/compiler-rt/lib/asan/asan_rtl.cpp
index d42a75e9e5211..f242a337a86c2 100644
--- a/compiler-rt/lib/asan/asan_rtl.cpp
+++ b/compiler-rt/lib/asan/asan_rtl.cpp
@@ -36,6 +36,9 @@
 uptr __asan_shadow_memory_dynamic_address;  // Global interface symbol.
 int __asan_option_detect_stack_use_after_return;  // Global interface symbol.
 uptr *__asan_test_only_reported_buggy_pointer;  // Used only for testing asan.
+bool __asan_is_dormant = true;
+
+void __asan_set_dormant(int dormancy) { __asan_is_dormant = dormancy; }
 
 namespace __asan {
 
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 5fc4d826e0015..780c2ed174622 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -179,6 +179,8 @@ const char kAMDGPUAddressPrivateName[] = "llvm.amdgcn.is.private";
 const char kAMDGPUBallotName[] = "llvm.amdgcn.ballot.i64";
 const char kAMDGPUUnreachableName[] = "llvm.amdgcn.unreachable";
 
+const char kAsanDormancyVarName[] = "__asan_is_dormant";
+
 // Accesses sizes are powers of two: 1, 2, 4, 8, 16.
 static const size_t kNumberOfAccessSizes = 5;
 
@@ -453,6 +455,10 @@ static cl::opt<int> ClDebugMin("asan-debug-min", cl::desc("Debug min inst"),
 static cl::opt<int> ClDebugMax("asan-debug-max", cl::desc("Debug max inst"),
                                cl::Hidden, cl::init(-1));
 
+static cl::opt<bool> CLAsanDormant("asan-dormant",
+                                   cl::desc("Makes asan dormant"), cl::Hidden,
+                                   cl::init(false));
+
 STATISTIC(NumInstrumentedReads, "Number of instrumented reads");
 STATISTIC(NumInstrumentedWrites, "Number of instrumented writes");
 STATISTIC(NumOptimizedAccessesToGlobalVar,
@@ -855,6 +861,7 @@ struct AddressSanitizer {
 
   FunctionCallee AsanMemmove, AsanMemcpy, AsanMemset;
   Value *LocalDynamicShadow = nullptr;
+  Constant *DormantAsanFlag;
   const StackSafetyGlobalInfo *SSGI;
   DenseMap<const AllocaInst *, bool> ProcessedAllocas;
 
@@ -1587,6 +1594,12 @@ bool AddressSanitizer::GlobalIsLinkerInitialized(GlobalVariable *G) {
 void AddressSanitizer::instrumentPointerComparisonOrSubtraction(
     Instruction *I, RuntimeCallInserter &RTCI) {
   IRBuilder<> IRB(I);
+
+  if (CLAsanDormant)
+    IRB.SetInsertPoint(SplitBlockAndInsertIfThen(
+        IRB.CreateNot(IRB.CreateLoad(IRB.getInt1Ty(), DormantAsanFlag)), I,
+        false));
+
   FunctionCallee F = isa<ICmpInst>(I) ? AsanPtrCmpFunction : AsanPtrSubFunction;
   Value *Param[2] = {I->getOperand(0), I->getOperand(1)};
   for (Value *&i : Param) {
@@ -1601,9 +1614,19 @@ static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
                                 MaybeAlign Alignment, unsigned Granularity,
                                 TypeSize TypeStoreSize, bool IsWrite,
                                 Value *SizeArgument, bool UseCalls,
-                                uint32_t Exp, RuntimeCallInserter &RTCI) {
+                                uint32_t Exp, RuntimeCallInserter &RTCI,
+                                Value *DormantAsanFlag) {
   // Instrument a 1-, 2-, 4-, 8-, or 16- byte access with one check
   // if the data is properly aligned.
+
+  Instruction *InsertPoint = InsertBefore;
+  if (CLAsanDormant) {
+    InstrumentationIRBuilder IRB(InsertPoint);
+    InsertPoint = SplitBlockAndInsertIfThen(
+        IRB.CreateNot(IRB.CreateLoad(IRB.getInt1Ty(), DormantAsanFlag)),
+        InsertBefore, false);
+  }
+
   if (!TypeStoreSize.isScalable()) {
     const auto FixedSize = TypeStoreSize.getFixedValue();
     switch (FixedSize) {
@@ -1614,12 +1637,12 @@ static void doInstrumentAddress(AddressSanitizer *Pass, Instruction *I,
     case 128:
       if (!Alignment || *Alignment >= Granularity ||
           *Alignment >= FixedSize / 8)
-        return Pass->instrumentAddress(I, InsertBefore, Addr, Alignment,
+        return Pass->instrumentAddress(I, InsertPoint, Addr, Alignment,
                                        FixedSize, IsWrite, nullptr, UseCalls,
                                        Exp, RTCI);
     }
   }
-  Pass->instrumentUnusualSizeOrAlignment(I, InsertBefore, Addr, TypeStoreSize,
+  Pass->instrumentUnusualSizeOrAlignment(I, InsertPoint, Addr, TypeStoreSize,
                                          IsWrite, nullptr, UseCalls, Exp, RTCI);
 }
 
@@ -1635,6 +1658,14 @@ void AddressSanitizer::instrumentMaskedLoadOrStore(
 
   IRBuilder IB(I);
   Instruction *LoopInsertBefore = I;
+
+  if (CLAsanDormant) {
+    LoopInsertBefore = SplitBlockAndInsertIfThen(
+        IB.CreateNot(IB.CreateLoad(IB.getInt1Ty(), DormantAsanFlag)),
+        LoopInsertBefore, false);
+    IB.SetInsertPoint(LoopInsertBefore);
+  }
+
   if (EVL) {
     // The end argument of SplitBlockAndInsertForLane is assumed bigger
     // than zero, so we should check whether EVL is zero here.
@@ -1685,7 +1716,7 @@ void AddressSanitizer::instrumentMaskedLoadOrStore(
     }
     doInstrumentAddress(Pass, I, &*IRB.GetInsertPoint(), InstrumentedAddress,
                         Alignment, Granularity, ElemTypeSize, IsWrite,
-                        SizeArgument, UseCalls, Exp, RTCI);
+                        SizeArgument, UseCalls, Exp, RTCI, DormantAsanFlag);
   });
 }
 
@@ -1742,7 +1773,7 @@ void AddressSanitizer::instrumentMop(ObjectSizeOffsetVisitor &ObjSizeVis,
   } else {
     doInstrumentAddress(this, O.getInsn(), O.getInsn(), Addr, O.Alignment,
                         Granularity, O.TypeStoreSize, O.IsWrite, nullptr,
-                        UseCalls, Exp, RTCI);
+                        UseCalls, Exp, RTCI, DormantAsanFlag);
   }
 }
 
@@ -1854,6 +1885,11 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
   }
 
   InstrumentationIRBuilder IRB(InsertBefore);
+  if (CLAsanDormant)
+    IRB.SetInsertPoint(SplitBlockAndInsertIfThen(
+        IRB.CreateNot(IRB.CreateLoad(IRB.getInt1Ty(), DormantAsanFlag)),
+        InsertBefore, false));
+
   size_t AccessSizeIndex = TypeStoreSizeToSizeIndex(TypeStoreSize);
 
   if (UseCalls && ClOptimizeCallbacks) {
@@ -2863,6 +2899,8 @@ void AddressSanitizer::initializeCallbacks(Module &M, const TargetLibraryInfo *T
       M.getOrInsertFunction(kAMDGPUAddressSharedName, IRB.getInt1Ty(), PtrTy);
   AMDGPUAddressPrivate =
       M.getOrInsertFunction(kAMDGPUAddressPrivateName, IRB.getInt1Ty(), PtrTy);
+
+  DormantAsanFlag = M.getOrInsertGlobal(kAsanDormancyVarName, IRB.getInt1Ty());
 }
 
 bool AddressSanitizer::maybeInsertAsanInitAtFunctionEntry(Function &F) {

>From c8355a276df51d6952ffe767c31ec26ec99cbfc1 Mon Sep 17 00:00:00 2001
From: Matthew Nagy <gbmatt at tiger-linux2.domain.snsys.com>
Date: Mon, 22 Jul 2024 14:37:42 +0000
Subject: [PATCH 2/3] Added compiler-rt side test

---
 compiler-rt/test/asan/TestCases/dormant.cpp | 37 +++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 compiler-rt/test/asan/TestCases/dormant.cpp

diff --git a/compiler-rt/test/asan/TestCases/dormant.cpp b/compiler-rt/test/asan/TestCases/dormant.cpp
new file mode 100644
index 0000000000000..5efa2f9836a24
--- /dev/null
+++ b/compiler-rt/test/asan/TestCases/dormant.cpp
@@ -0,0 +1,37 @@
+// RUN: %clangxx_asan -DREAD -O0 -mllvm -asan-dormant %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-READ
+// RUN: %clangxx_asan -O0 -mllvm -asan-dormant %s -o %t && not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-WRITE
+// REQUIRES: stable-runtime
+
+#include <sanitizer/asan_interface.h>
+int readHeapAfterFree(){
+  int * volatile x = new int[10];
+  delete[] x;
+  return x[5];
+}
+
+static int * volatile y;
+int writeHeapAfterFree(){
+  y = new int[10];
+  delete[] y;
+  return y[5] = 413;
+}
+
+int main() {
+#ifdef READ
+  readHeapAfterFree();
+  // CHECK-READCHECK-NOT {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+  __asan_set_dormant(false);
+  readHeapAfterFree();
+  // CHECK-READ: {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+
+#else
+
+  writeHeapAfterFree();
+  // CHECK-WRITE-NOT {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+  __asan_set_dormant(false);
+  writeHeapAfterFree();
+  // CHECK-WRITE: {{.*ERROR: AddressSanitizer: heap-use-after-free on address}}
+#endif
+
+  return 0;
+}

>From 960c610eca66559e7f4759e10b5a1870cc453c87 Mon Sep 17 00:00:00 2001
From: Matthew Nagy <gbmatt at tiger-linux2.domain.snsys.com>
Date: Wed, 7 Aug 2024 15:38:59 +0000
Subject: [PATCH 3/3] Fixed a codegen bug

---
 llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 780c2ed174622..911f4f8ad6398 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -1885,10 +1885,6 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
   }
 
   InstrumentationIRBuilder IRB(InsertBefore);
-  if (CLAsanDormant)
-    IRB.SetInsertPoint(SplitBlockAndInsertIfThen(
-        IRB.CreateNot(IRB.CreateLoad(IRB.getInt1Ty(), DormantAsanFlag)),
-        InsertBefore, false));
 
   size_t AccessSizeIndex = TypeStoreSizeToSizeIndex(TypeStoreSize);
 
@@ -1972,6 +1968,11 @@ void AddressSanitizer::instrumentUnusualSizeOrAlignment(
     TypeSize TypeStoreSize, bool IsWrite, Value *SizeArgument, bool UseCalls,
     uint32_t Exp, RuntimeCallInserter &RTCI) {
   InstrumentationIRBuilder IRB(InsertBefore);
+  if (CLAsanDormant)
+    IRB.SetInsertPoint(SplitBlockAndInsertIfThen(
+        IRB.CreateNot(IRB.CreateLoad(IRB.getInt1Ty(), DormantAsanFlag)),
+        InsertBefore, false));
+
   Value *NumBits = IRB.CreateTypeSize(IntptrTy, TypeStoreSize);
   Value *Size = IRB.CreateLShr(NumBits, ConstantInt::get(IntptrTy, 3));
 



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