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 "berberis/runtime_primitives/recovery_code.h"
18
19 #include <cstdint>
20 #include <initializer_list>
21 #include <utility>
22
23 #include "berberis/base/checks.h"
24 #include "berberis/base/forever_map.h"
25 #include "berberis/base/tracing.h"
26 #include "berberis/guest_state/guest_state_opaque.h"
27 #include "berberis/runtime_primitives/code_pool.h"
28
29 namespace berberis {
30
31 namespace {
32
33 ForeverMap<uintptr_t, uintptr_t> g_recovery_map;
34 bool g_recovery_map_initialized_ = false;
35
FindExtraRecoveryCodeUnsafe(uintptr_t fault_addr)36 uintptr_t FindExtraRecoveryCodeUnsafe(uintptr_t fault_addr) {
37 CHECK(g_recovery_map_initialized_);
38 auto it = g_recovery_map.find(fault_addr);
39 if (it != g_recovery_map.end()) {
40 return it->second;
41 }
42 return 0;
43 }
44
45 } // namespace
46
InitExtraRecoveryCodeUnsafe(std::initializer_list<std::pair<uintptr_t,uintptr_t>> fault_recovery_pairs)47 void InitExtraRecoveryCodeUnsafe(
48 std::initializer_list<std::pair<uintptr_t, uintptr_t>> fault_recovery_pairs) {
49 CHECK(!g_recovery_map_initialized_);
50 for (auto pair : fault_recovery_pairs) {
51 g_recovery_map[pair.first] = pair.second;
52 }
53 g_recovery_map_initialized_ = true;
54 }
55
FindRecoveryCode(uintptr_t fault_addr,ThreadState * state)56 uintptr_t FindRecoveryCode(uintptr_t fault_addr, ThreadState* state) {
57 uintptr_t recovery_addr;
58 CHECK(state);
59 // Only look up in CodePool if we are inside generated code (interrupted by a
60 // signal). If a signal interrupts CodePool::Add then calling FindRecoveryCode
61 // in this state can cause deadlock.
62 if (GetResidence(*state) == kInsideGeneratedCode) {
63 // TODO(b/228188293): we might need to traverse all code pool instances.
64 recovery_addr = GetDefaultCodePoolInstance()->FindRecoveryCode(fault_addr);
65 if (recovery_addr) {
66 return recovery_addr;
67 }
68 }
69 // Extra recovery code is in read-only mode after the init, so we don't need mutexes.
70 // Note, that we cannot simply add extra recovery code to CodePool, since these
71 // fault addresses may be outside of generated code (e.g. interpreter).
72 recovery_addr = FindExtraRecoveryCodeUnsafe(fault_addr);
73 if (recovery_addr) {
74 TRACE("found recovery address outside of code pool");
75 }
76 return recovery_addr;
77 }
78
79 } // namespace berberis
80