[cfi] Safe handling of unaddressable vtable pointers (compiler-rt).

Avoid crashing when printing diagnostics for vtable-related CFI
errors. In diagnostic mode, the frontend does an additional check of
the vtable pointer against the set of all known vtable addresses and
lets the runtime handler know if it is safe to inspect the vtable.

http://reviews.llvm.org/D16824

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@259717 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 44 insertions, 0 deletions

diff --git a/test/cfi/target_uninstrumented.cpp b/test/cfi/target_uninstrumented.cpp
new file mode 100644
index 000000000..2ec2b5bbc
--- /dev/null
+++ b/test/cfi/target_uninstrumented.cpp
@@ -0,0 +1,44 @@
+// RUN: %clangxx -g -DSHARED_LIB %s -fPIC -shared -o %T/target_uninstrumented-so.so
+// RUN: %clangxx_cfi_diag -g %s -o %t %T/target_uninstrumented-so.so
+// RUN: %t 2>&1 | FileCheck %s
+
+// REQUIRES: cxxabi
+
+#include <stdio.h>
+#include <string.h>
+
+struct A {
+  virtual void f();
+};
+
+void *create_B();
+
+#ifdef SHARED_LIB
+
+struct B {
+  virtual void f();
+};
+void B::f() {}
+
+void *create_B() {
+  return (void *)(new B());
+}
+
+#else
+
+void A::f() {}
+
+int main(int argc, char *argv[]) {
+  void *p = create_B();
+  // CHECK: runtime error: control flow integrity check for type 'A' failed during cast to unrelated type
+  // CHECK: invalid vtable in module {{.*}}target_uninstrumented-so.so
+  A *a = (A *)p;
+  memset(p, 0, sizeof(A));
+  // CHECK: runtime error: control flow integrity check for type 'A' failed during cast to unrelated type
+  // CHECK-NOT: invalid vtable in module
+  // CHECK: invalid vtable
+  a = (A *)p;
+  // CHECK: done
+  fprintf(stderr, "done %p\n", a);
+}
+#endif