non ub exploit mode: fix false positive with fn calls

AliveToolkit · Aug 25, 2023 · ce35c2b · ce35c2b
1 parent aa78abe
commit ce35c2b
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Showing 3 changed files with 24 additions and 3 deletions.
diff --git a/ir/instr.cpp b/ir/instr.cpp
@@ -2067,8 +2067,16 @@ unique_ptr<Instr> InsertValue::dup(Function &f, const string &suffix) const {
   return ret;
 }
 
+
 DEFINE_AS_RETZERO(FnCall, getMaxGEPOffset);
 
+FnCall::FnCall(Type &type, string &&name, string &&fnName, FnAttrs &&attrs)
+  : MemInstr(type, std::move(name)), fnName(std::move(fnName)),
+    attrs(std::move(attrs)) {
+  if (config::disallow_ub_exploitation)
+    this->attrs.set(FnAttrs::NoUndef);
+}
+
 pair<uint64_t, uint64_t> FnCall::getMaxAllocSize() const {
   if (!hasAttribute(FnAttrs::AllocSize))
     return { 0, 1 };

diff --git a/ir/instr.h b/ir/instr.h
@@ -1024,9 +1024,7 @@ class FnCall : public MemInstr {
 
 public:
   FnCall(Type &type, std::string &&name, std::string &&fnName,
-         FnAttrs &&attrs = FnAttrs::None)
-    : MemInstr(type, std::move(name)), fnName(std::move(fnName)),
-      attrs(std::move(attrs)) {}
+         FnAttrs &&attrs = FnAttrs::None);
   void addArg(Value &arg, ParamAttrs &&attrs);
   const auto& getFnName() const { return fnName; }
   const auto& getArgs() const { return args; }

diff --git a/tests/alive-tv/non-ub-exploitation/fncall.srctgt.ll b/tests/alive-tv/non-ub-exploitation/fncall.srctgt.ll
@@ -0,0 +1,15 @@
+; TEST-ARGS: -disallow-ub-exploitation
+
+declare ptr @fn() null_pointer_is_valid
+
+define i32 @src() null_pointer_is_valid {
+  %call1 = call ptr @fn()
+  load i32, ptr %call1, align 1
+  ret i32 0
+}
+
+define i32 @tgt() null_pointer_is_valid {
+  %call1 = call ptr @fn()
+  load i32, ptr %call1, align 1
+  ret i32 0
+}