1 /*
2 * Copyright (C) 2022 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 #ifndef ART_RUNTIME_JNI_LOCAL_REFERENCE_TABLE_INL_H_
18 #define ART_RUNTIME_JNI_LOCAL_REFERENCE_TABLE_INL_H_
19
20 #include "local_reference_table.h"
21
22 #include "android-base/stringprintf.h"
23
24 #include "base/casts.h"
25 #include "gc_root-inl.h"
26 #include "obj_ptr-inl.h"
27 #include "mirror/object_reference.h"
28 #include "verify_object.h"
29
30 namespace art HIDDEN {
31 namespace jni {
32
SetReference(ObjPtr<mirror::Object> ref)33 inline void LrtEntry::SetReference(ObjPtr<mirror::Object> ref) {
34 root_ = GcRoot<mirror::Object>(
35 mirror::CompressedReference<mirror::Object>::FromMirrorPtr(ref.Ptr()));
36 DCHECK(!IsFree());
37 DCHECK(!IsSerialNumber());
38 }
39
GetReference()40 inline ObjPtr<mirror::Object> LrtEntry::GetReference() {
41 DCHECK(!IsFree());
42 DCHECK(!IsSerialNumber());
43 DCHECK(!IsNull());
44 // Local references do not need read barriers. They are marked during the thread root flip.
45 return root_.Read<kWithoutReadBarrier>();
46 }
47
SetNextFree(uint32_t next_free)48 inline void LrtEntry::SetNextFree(uint32_t next_free) {
49 SetVRegValue(NextFreeField::Update(next_free, 1u << kFlagFree));
50 DCHECK(IsFree());
51 DCHECK(!IsSerialNumber());
52 }
53
SetSerialNumber(uint32_t serial_number)54 inline void LrtEntry::SetSerialNumber(uint32_t serial_number) {
55 SetVRegValue(SerialNumberField::Update(serial_number, 1u << kFlagSerialNumber));
56 DCHECK(!IsFree());
57 DCHECK(IsSerialNumber());
58 }
59
SetVRegValue(uint32_t value)60 inline void LrtEntry::SetVRegValue(uint32_t value) {
61 root_ = GcRoot<mirror::Object>(
62 mirror::CompressedReference<mirror::Object>::FromVRegValue(value));
63 }
64
GetReferenceEntryIndex(IndirectRef iref)65 inline uint32_t LocalReferenceTable::GetReferenceEntryIndex(IndirectRef iref) const {
66 DCHECK_EQ(IndirectReferenceTable::GetIndirectRefKind(iref), kLocal);
67 LrtEntry* entry = ToLrtEntry(iref);
68
69 if (LIKELY(small_table_ != nullptr)) {
70 DCHECK(tables_.empty());
71 if (!std::less<const LrtEntry*>()(entry, small_table_) &&
72 std::less<const LrtEntry*>()(entry, small_table_ + kSmallLrtEntries)) {
73 return dchecked_integral_cast<uint32_t>(entry - small_table_);
74 }
75 } else {
76 for (size_t i = 0, size = tables_.size(); i != size; ++i) {
77 LrtEntry* table = tables_[i];
78 size_t table_size = GetTableSize(i);
79 if (!std::less<const LrtEntry*>()(entry, table) &&
80 std::less<const LrtEntry*>()(entry, table + table_size)) {
81 return dchecked_integral_cast<size_t>(i != 0u ? table_size : 0u) +
82 dchecked_integral_cast<size_t>(entry - table);
83 }
84 }
85 }
86 return std::numeric_limits<uint32_t>::max();
87 }
88
IsValidReference(IndirectRef iref,std::string * error_msg)89 inline bool LocalReferenceTable::IsValidReference(IndirectRef iref,
90 /*out*/std::string* error_msg) const {
91 uint32_t entry_index = GetReferenceEntryIndex(iref);
92 if (UNLIKELY(entry_index == std::numeric_limits<uint32_t>::max())) {
93 *error_msg = android::base::StringPrintf("reference outside the table: %p", iref);
94 return false;
95 }
96 if (UNLIKELY(entry_index >= segment_state_.top_index)) {
97 *error_msg = android::base::StringPrintf("popped reference at index %u in a table of size %u",
98 entry_index,
99 segment_state_.top_index);
100 return false;
101 }
102 LrtEntry* entry = ToLrtEntry(iref);
103 LrtEntry* serial_number_entry = GetCheckJniSerialNumberEntry(entry);
104 if (serial_number_entry->IsSerialNumber()) {
105 // This reference was created with CheckJNI enabled.
106 uint32_t expected_serial_number = serial_number_entry->GetSerialNumber();
107 uint32_t serial_number = entry - serial_number_entry;
108 DCHECK_LT(serial_number, kCheckJniEntriesPerReference);
109 if (serial_number != expected_serial_number || serial_number == 0u) {
110 *error_msg = android::base::StringPrintf(
111 "reference at index %u with bad serial number %u v. %u (valid 1 - %u)",
112 entry_index,
113 serial_number,
114 expected_serial_number,
115 dchecked_integral_cast<uint32_t>(kCheckJniEntriesPerReference - 1u));
116 return false;
117 }
118 }
119 if (UNLIKELY(entry->IsFree())) {
120 *error_msg = android::base::StringPrintf("deleted reference at index %u", entry_index);
121 return false;
122 }
123 if (UNLIKELY(entry->IsNull())) {
124 // This should never really happen and may indicate memory coruption.
125 *error_msg = android::base::StringPrintf("null reference at index %u", entry_index);
126 return false;
127 }
128 return true;
129 }
130
DCheckValidReference(IndirectRef iref)131 inline void LocalReferenceTable::DCheckValidReference(IndirectRef iref) const {
132 // If CheckJNI is performing the checks, we should not reach this point with an invalid
133 // reference with the exception of gtests that intercept the CheckJNI abort and proceed
134 // to decode the reference anyway and we do not want to abort again in this case.
135 if (kIsDebugBuild && !IsCheckJniEnabled()) {
136 std::string error_msg;
137 CHECK(IsValidReference(iref, &error_msg)) << error_msg;
138 }
139 }
140
Get(IndirectRef iref)141 inline ObjPtr<mirror::Object> LocalReferenceTable::Get(IndirectRef iref) const {
142 DCheckValidReference(iref);
143 return ToLrtEntry(iref)->GetReference();
144 }
145
Update(IndirectRef iref,ObjPtr<mirror::Object> obj)146 inline void LocalReferenceTable::Update(IndirectRef iref, ObjPtr<mirror::Object> obj) {
147 DCheckValidReference(iref);
148 ToLrtEntry(iref)->SetReference(obj);
149 }
150
151 } // namespace jni
152 } // namespace art
153
154 #endif // ART_RUNTIME_JNI_LOCAL_REFERENCE_TABLE_INL_H_
155