[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 150868d..ce5d43a 100644
--- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -60,6 +60,7 @@
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 @@
// (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 @@
} 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 @@
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) {