1 /*
2 * Copyright (C) 2014 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/assembler/machine_code.h"
18
19 #include <bit>
20 #include <string>
21
22 #include "berberis/base/bit_util.h"
23 #include "berberis/base/logging.h"
24
25 namespace berberis {
26
AddrOf(uint32_t offset)27 uint8_t* MachineCode::AddrOf(uint32_t offset) {
28 CHECK_LT(offset, code_.size());
29 return &code_[offset];
30 }
31
AddrOf(uint32_t offset) const32 const uint8_t* MachineCode::AddrOf(uint32_t offset) const {
33 CHECK_LT(offset, code_.size());
34 return &code_[offset];
35 }
36
Grow(uint32_t count)37 uint32_t MachineCode::Grow(uint32_t count) {
38 size_t old_size = code_.size();
39 code_.resize(old_size + count);
40 return old_size;
41 }
42
print_halfbyte(uint8_t b)43 inline char print_halfbyte(uint8_t b) {
44 return b < 0xa ? b + '0' : (b - 0xa) + 'a';
45 }
46
print_byte(uint8_t b)47 inline std::string print_byte(uint8_t b) {
48 std::string byte_str = "";
49 byte_str += print_halfbyte(b >> 4);
50 byte_str += print_halfbyte(b & 0xf);
51 return byte_str;
52 }
53
AsString(std::string * result,InstructionSize insn_size) const54 void MachineCode::AsString(std::string* result, InstructionSize insn_size) const {
55 if (insn_size == InstructionSize::OneByte) {
56 for (uint8_t insn : code_) {
57 *result += print_byte(insn);
58 *result += ' ';
59 }
60 } else {
61 for (uint32_t i = 0; i + 3 < code_.size(); i += 4) {
62 *result += print_byte(code_[i + 3]);
63 *result += print_byte(code_[i + 2]);
64 *result += print_byte(code_[i + 1]);
65 *result += print_byte(code_[i]);
66 *result += ' ';
67 }
68 }
69 }
70
PerformRelocations(const uint8_t * code,RecoveryMap * recovery_map)71 void MachineCode::PerformRelocations(const uint8_t* code, RecoveryMap* recovery_map) {
72 for (const auto& rel : relocations_) {
73 switch (rel.type) {
74 case RelocationType::RelocAbsToDisp32: {
75 intptr_t start = std::bit_cast<intptr_t>(code);
76 intptr_t pc = start + rel.pc;
77 intptr_t disp = rel.data - pc;
78 CHECK(IsInRange<int32_t>(disp));
79 *AddrAs<int32_t>(rel.dst) = disp;
80 break;
81 }
82 case RelocationType::RelocRecoveryPoint: {
83 uintptr_t start = reinterpret_cast<uintptr_t>(code);
84 uintptr_t fault_addr = start + rel.pc;
85 uintptr_t recovery_addr = start + rel.data;
86 (*recovery_map)[fault_addr] = recovery_addr;
87 break;
88 }
89 }
90 }
91 }
92
DumpCode(InstructionSize insn_size) const93 void MachineCode::DumpCode(InstructionSize insn_size) const {
94 std::string code_str;
95 AsString(&code_str, insn_size);
96 ALOGE("%s\n", code_str.c_str());
97 }
98
99 } // namespace berberis
100