// RUN: %clangxx_cfi -o %t1 %s // RUN: %expect_crash_unless_devirt %t1 2>&1 | FileCheck --check-prefix=CFI %s // RUN: %clangxx_cfi -DB32 -o %t2 %s // RUN: %expect_crash %t2 2>&1 | FileCheck --check-prefix=CFI %s // RUN: %clangxx_cfi -DB64 -o %t3 %s // RUN: %expect_crash %t3 2>&1 | FileCheck --check-prefix=CFI %s // RUN: %clangxx_cfi -DBM -o %t4 %s // RUN: %expect_crash %t4 2>&1 | FileCheck --check-prefix=CFI %s // RUN: %clangxx -o %t5 %s // RUN: %t5 2>&1 | FileCheck --check-prefix=NCFI %s // RUN: %clangxx_cfi_diag -o %t6 %s // RUN: %t6 2>&1 | FileCheck --check-prefix=CFI-DIAG %s // Tests that the CFI mechanism crashes the program when a virtual table is // replaced with a compatible table of function pointers that does not belong to // any class, by manually overwriting the virtual table of an object and // attempting to make a call through it. // REQUIRES: cxxabi #include <stdio.h> #include "utils.h" struct A { virtual void f(); }; void A::f() {} void foo() { fprintf(stderr, "foo\n"); } void *fake_vtable[] = { 0, 0, (void *)&foo }; int main() { create_derivers<A>(); A *a = new A; *((void **)a) = fake_vtable + 2; // UB here break_optimization(a); // CFI: 1 // NCFI: 1 fprintf(stderr, "1\n"); // CFI-NOT: foo // NCFI: foo // CFI-DIAG: runtime error: control flow integrity check for type 'A' failed during virtual call // CFI-DIAG-NEXT: note: invalid vtable a->f(); // We don't check for the absence of a 2 here because under devirtualization // our virtual call may be devirtualized and we will proceed with execution // rather than crashing. // NCFI: {{^2$}} fprintf(stderr, "2\n"); }