1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <assert.h>
18 #include <stdint.h>
19 #include <stdlib.h>
20
21 // This library is built for all targets, including host tests, so __cfi_slowpath may not be
22 // present. But it is only used in the bionic loader tests.
23 extern "C" __attribute__((weak)) void __cfi_slowpath(uint64_t, void*);
24
25 static int g_count;
26 static uint64_t g_last_type_id;
27 static void* g_last_address;
28 static void* g_last_diag;
29
30 extern "C" {
31
32 // Mock a CFI-enabled library without relying on the compiler.
__cfi_check(uint64_t CallSiteTypeId,void * TargetAddr,void * Diag)33 __attribute__((aligned(4096))) void __cfi_check(uint64_t CallSiteTypeId, void* TargetAddr,
34 void* Diag) {
35 ++g_count;
36 g_last_type_id = CallSiteTypeId;
37 g_last_address = TargetAddr;
38 g_last_diag = Diag;
39 }
40
get_count()41 int get_count() {
42 return g_count;
43 }
44
get_last_type_id()45 uint64_t get_last_type_id() {
46 return g_last_type_id;
47 }
48
get_last_address()49 void* get_last_address() {
50 return g_last_address;
51 }
52
get_last_diag()53 void* get_last_diag() {
54 return g_last_diag;
55 }
56
get_global_address()57 void* get_global_address() {
58 return &g_count;
59 }
60 }
61
62 // Check that CFI is set up in module constructors and destructors.
63 struct A {
check_cfi_selfA64 void check_cfi_self() {
65 g_last_type_id = 0;
66 assert(&__cfi_slowpath);
67 // CFI check for an invalid address. Normally, this would kill the process by routing the call
68 // back to the calling module's __cfi_check, which does the right thing based on
69 // -fsanitize-recover / -fsanitize-trap. But this module has custom __cfi_check that does not do
70 // any of that, so the result looks like a passing check.
71 int zz;
72 __cfi_slowpath(13, static_cast<void*>(&zz));
73 assert(g_last_type_id == 13);
74 // CFI check for a libc function. This never goes into this module's __cfi_check, and must pass.
75 __cfi_slowpath(14, reinterpret_cast<void*>(&exit));
76 assert(g_last_type_id == 13);
77 }
AA78 A() {
79 check_cfi_self();
80 }
~AA81 ~A() {
82 check_cfi_self();
83 }
84 } a;
85