1 // RUN: %clangxx_cfi -o %t1 %s
2 // RUN: %expect_crash_unless_devirt %t1 2>&1 | FileCheck --check-prefix=CFI %s
3
4 // RUN: %clangxx_cfi -DB32 -o %t2 %s
5 // RUN: %expect_crash %t2 2>&1 | FileCheck --check-prefix=CFI %s
6
7 // RUN: %clangxx_cfi -DB64 -o %t3 %s
8 // RUN: %expect_crash %t3 2>&1 | FileCheck --check-prefix=CFI %s
9
10 // RUN: %clangxx_cfi -DBM -o %t4 %s
11 // RUN: %expect_crash %t4 2>&1 | FileCheck --check-prefix=CFI %s
12
13 // RUN: %clangxx -o %t5 %s
14 // RUN: %t5 2>&1 | FileCheck --check-prefix=NCFI %s
15
16 // RUN: %clangxx_cfi_diag -o %t6 %s
17 // RUN: %t6 2>&1 | FileCheck --check-prefix=CFI-DIAG %s
18
19 // Tests that the CFI mechanism crashes the program when a virtual table is
20 // replaced with a compatible table of function pointers that does not belong to
21 // any class, by manually overwriting the virtual table of an object and
22 // attempting to make a call through it.
23
24 // REQUIRES: cxxabi
25
26 #include <stdio.h>
27 #include "utils.h"
28
29 struct A {
30 virtual void f();
31 };
32
f()33 void A::f() {}
34
foo()35 void foo() {
36 fprintf(stderr, "foo\n");
37 }
38
39 void *fake_vtable[] = { 0, 0, (void *)&foo };
40
main()41 int main() {
42 create_derivers<A>();
43
44 A *a = new A;
45 *((void **)a) = fake_vtable + 2; // UB here
46 break_optimization(a);
47
48 // CFI: 1
49 // NCFI: 1
50 fprintf(stderr, "1\n");
51
52 // CFI-NOT: foo
53 // NCFI: foo
54 // CFI-DIAG: runtime error: control flow integrity check for type 'A' failed during virtual call
55 // CFI-DIAG-NEXT: note: invalid vtable
56 a->f();
57
58 // We don't check for the absence of a 2 here because under devirtualization
59 // our virtual call may be devirtualized and we will proceed with execution
60 // rather than crashing.
61
62 // NCFI: {{^2$}}
63 fprintf(stderr, "2\n");
64 }
65