[asan] unpoison the stack before every noreturn call. Fixes asan issue 37. llvm part

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150102 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 150868d5776d7e7ae87d240ff73723fcf56f1353..ce5d43a68fce9a52cd12977a1c70f80bca46a6fc 100644 (file)
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -60,6 +60,7 @@ static const char *kAsanReportErrorTemplate = "__asan_report_";
 static const char *kAsanRegisterGlobalsName = "__asan_register_globals";
 static const char *kAsanUnregisterGlobalsName = "__asan_unregister_globals";
 static const char *kAsanInitName = "__asan_init";
+static const char *kAsanHandleNoReturnName = "__asan_handle_no_return";
 static const char *kAsanMappingOffsetName = "__asan_mapping_offset";
 static const char *kAsanMappingScaleName = "__asan_mapping_scale";
 static const char *kAsanStackMallocName = "__asan_stack_malloc";
@@ -649,6 +650,7 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) {
   // (unless there are calls between uses).
   SmallSet<Value*, 16> TempsToInstrument;
   SmallVector<Instruction*, 16> ToInstrument;
+  SmallVector<Instruction*, 8> NoReturnCalls;
 
   // Fill the set of memory operations to instrument.
   for (Function::iterator FI = F.begin(), FE = F.end();
@@ -667,9 +669,12 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) {
       } else if (isa<MemIntrinsic>(BI) && ClMemIntrin) {
         // ok, take it.
       } else {
-        if (isa<CallInst>(BI)) {
+        if (CallInst *CI = dyn_cast<CallInst>(BI)) {
           // A call inside BB.
           TempsToInstrument.clear();
+          if (CI->doesNotReturn()) {
+            NoReturnCalls.push_back(CI);
+          }
         }
         continue;
       }
@@ -694,7 +699,17 @@ bool AddressSanitizer::handleFunction(Module &M, Function &F) {
   DEBUG(dbgs() << F);
 
   bool ChangedStack = poisonStackInFunction(M, F);
-  return NumInstrumented > 0 || ChangedStack;
+
+  // 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) {

diff --git a/test/Instrumentation/AddressSanitizer/instrument-no-return.ll b/test/Instrumentation/AddressSanitizer/instrument-no-return.ll
new file mode 100644 (file)
index 0000000..80f1b1c
--- /dev/null
+++ b/test/Instrumentation/AddressSanitizer/instrument-no-return.ll
@@ -0,0 +1,17 @@
+; RUN: opt < %s -asan -S | FileCheck %s
+; AddressSanitizer must insert __asan_handle_no_return
+; before every noreturn call.
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-unknown-linux-gnu"
+
+declare void @MyNoReturnFunc(i32) noreturn
+
+define i32 @_Z5ChildPv(i8* nocapture %arg) uwtable address_safety {
+entry:
+  call void @MyNoReturnFunc(i32 1) noreturn
+  unreachable
+}
+
+; CHECK:        call void @__asan_handle_no_return
+; CHECK-NEXT:   call void @MyNoReturnFunc