1 /*
2 * Copyright (C) 2023 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 "gtest/gtest.h"
18
19 #include <csignal>
20 #include <cstddef>
21 #include <cstdint>
22
23 #include "berberis/base/checks.h"
24
25 #include "faulty_memory_accesses.h"
26
27 namespace berberis {
28
29 namespace {
30
31 #if defined(__i386__)
32 constexpr size_t kRegIP = REG_EIP;
33 #elif defined(__x86_64__)
34 constexpr size_t kRegIP = REG_RIP;
35 #else
36 #error "Unsupported arch"
37 #endif
38
FaultHandler(int,siginfo_t *,void * ctx)39 void FaultHandler(int /* sig */, siginfo_t* /* info */, void* ctx) {
40 ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(ctx);
41 static_assert(sizeof(void*) == sizeof(greg_t), "Unsupported type sizes");
42 void* fault_addr = reinterpret_cast<void*>(ucontext->uc_mcontext.gregs[kRegIP]);
43 void* recovery_addr = FindFaultyMemoryAccessRecoveryAddrForTesting(fault_addr);
44 CHECK(recovery_addr);
45 ucontext->uc_mcontext.gregs[kRegIP] = reinterpret_cast<greg_t>(recovery_addr);
46 }
47
48 class ScopedFaultySigaction {
49 public:
ScopedFaultySigaction()50 ScopedFaultySigaction() {
51 struct sigaction sa;
52 sa.sa_flags = SA_SIGINFO;
53 sigemptyset(&sa.sa_mask);
54 sa.sa_sigaction = FaultHandler;
55 CHECK_EQ(sigaction(SIGSEGV, &sa, &old_sa_), 0);
56 }
57
~ScopedFaultySigaction()58 ~ScopedFaultySigaction() { CHECK_EQ(sigaction(SIGSEGV, &old_sa_, nullptr), 0); }
59
60 private:
61 struct sigaction old_sa_;
62 };
63
TEST(FaultyMemoryAccessesTest,FaultyLoadSuccess)64 TEST(FaultyMemoryAccessesTest, FaultyLoadSuccess) {
65 ScopedFaultySigaction scoped_sa;
66 uint64_t data = 0xffff'eeee'cccc'bbaaULL;
67 FaultyLoadResult result;
68
69 result = FaultyLoad(&data, 1);
70 EXPECT_EQ(result.value, static_cast<uint8_t>(data));
71 EXPECT_FALSE(result.is_fault);
72
73 result = FaultyLoad(&data, 2);
74 EXPECT_EQ(result.value, static_cast<uint16_t>(data));
75 EXPECT_FALSE(result.is_fault);
76
77 result = FaultyLoad(&data, 4);
78 EXPECT_EQ(result.value, static_cast<uint32_t>(data));
79 EXPECT_FALSE(result.is_fault);
80
81 result = FaultyLoad(&data, 8);
82 EXPECT_EQ(result.value, data);
83 EXPECT_FALSE(result.is_fault);
84 }
85
TEST(FaultyMemoryAccessesTest,FaultyLoadFault)86 TEST(FaultyMemoryAccessesTest, FaultyLoadFault) {
87 ScopedFaultySigaction scoped_sa;
88 FaultyLoadResult result;
89
90 result = FaultyLoad(nullptr, 1);
91 EXPECT_TRUE(result.is_fault);
92 result = FaultyLoad(nullptr, 2);
93 EXPECT_TRUE(result.is_fault);
94 result = FaultyLoad(nullptr, 4);
95 EXPECT_TRUE(result.is_fault);
96 result = FaultyLoad(nullptr, 8);
97 EXPECT_TRUE(result.is_fault);
98 }
99
TEST(FaultyMemoryAccessesTest,FaultyStoreSuccess)100 TEST(FaultyMemoryAccessesTest, FaultyStoreSuccess) {
101 ScopedFaultySigaction scoped_sa;
102 uint64_t data = 0xffff'eeee'cccc'bbaaULL;
103 uint64_t storage = 0;
104
105 bool is_fault = FaultyStore(&storage, 1, data);
106 EXPECT_EQ(static_cast<uint8_t>(storage), static_cast<uint8_t>(data));
107 EXPECT_FALSE(is_fault);
108
109 is_fault = FaultyStore(&storage, 2, data);
110 EXPECT_EQ(static_cast<uint16_t>(storage), static_cast<uint16_t>(data));
111 EXPECT_FALSE(is_fault);
112
113 is_fault = FaultyStore(&storage, 4, data);
114 EXPECT_EQ(static_cast<uint32_t>(storage), static_cast<uint32_t>(data));
115 EXPECT_FALSE(is_fault);
116
117 is_fault = FaultyStore(&storage, 8, data);
118 EXPECT_EQ(storage, data);
119 EXPECT_FALSE(is_fault);
120 }
121
TEST(FaultyMemoryAccessesTest,FaultyStoreFault)122 TEST(FaultyMemoryAccessesTest, FaultyStoreFault) {
123 ScopedFaultySigaction scoped_sa;
124
125 bool is_fault = FaultyStore(nullptr, 1, 0);
126 EXPECT_TRUE(is_fault);
127 is_fault = FaultyStore(nullptr, 2, 0);
128 EXPECT_TRUE(is_fault);
129 is_fault = FaultyStore(nullptr, 4, 0);
130 EXPECT_TRUE(is_fault);
131 is_fault = FaultyStore(nullptr, 8, 0);
132 EXPECT_TRUE(is_fault);
133 }
134
135 } // namespace
136
137 } // namespace berberis
138