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 "disassembler_arm64.h"
18 
19 #include <inttypes.h>
20 
21 #include <sstream>
22 
23 #include "base/logging.h"
24 #include "base/stringprintf.h"
25 #include "thread.h"
26 
27 namespace art {
28 namespace arm64 {
29 
30 // This enumeration should mirror the declarations in
31 // runtime/arch/arm64/registers_arm64.h. We do not include that file to
32 // avoid a dependency on libart.
33 enum {
34   TR  = 19,
35   IP0 = 16,
36   IP1 = 17,
37   FP  = 29,
38   LR  = 30
39 };
40 
AppendRegisterNameToOutput(const vixl::Instruction * instr,const vixl::CPURegister & reg)41 void CustomDisassembler::AppendRegisterNameToOutput(
42     const vixl::Instruction* instr,
43     const vixl::CPURegister& reg) {
44   USE(instr);
45   if (reg.IsRegister() && reg.Is64Bits()) {
46     if (reg.code() == TR) {
47       AppendToOutput("tr");
48       return;
49     } else if (reg.code() == LR) {
50       AppendToOutput("lr");
51       return;
52     }
53     // Fall through.
54   }
55   // Print other register names as usual.
56   Disassembler::AppendRegisterNameToOutput(instr, reg);
57 }
58 
VisitLoadLiteral(const vixl::Instruction * instr)59 void CustomDisassembler::VisitLoadLiteral(const vixl::Instruction* instr) {
60   Disassembler::VisitLoadLiteral(instr);
61 
62   if (!read_literals_) {
63     return;
64   }
65 
66   // Get address of literal. Bail if not within expected buffer range to
67   // avoid trying to fetch invalid literals (we can encounter this when
68   // interpreting raw data as instructions).
69   void* data_address = instr->LiteralAddress<void*>();
70   if (data_address < base_address_ || data_address >= end_address_) {
71     AppendToOutput(" (?)");
72     return;
73   }
74 
75   // Output information on literal.
76   vixl::Instr op = instr->Mask(vixl::LoadLiteralMask);
77   switch (op) {
78     case vixl::LDR_w_lit:
79     case vixl::LDR_x_lit:
80     case vixl::LDRSW_x_lit: {
81       int64_t data = op == vixl::LDR_x_lit ? *reinterpret_cast<int64_t*>(data_address)
82                                            : *reinterpret_cast<int32_t*>(data_address);
83       AppendToOutput(" (0x%" PRIx64 " / %" PRId64 ")", data, data);
84       break;
85     }
86     case vixl::LDR_s_lit:
87     case vixl::LDR_d_lit: {
88       double data = (op == vixl::LDR_s_lit) ? *reinterpret_cast<float*>(data_address)
89                                             : *reinterpret_cast<double*>(data_address);
90       AppendToOutput(" (%g)", data);
91       break;
92     }
93     default:
94       break;
95   }
96 }
97 
VisitLoadStoreUnsignedOffset(const vixl::Instruction * instr)98 void CustomDisassembler::VisitLoadStoreUnsignedOffset(const vixl::Instruction* instr) {
99   Disassembler::VisitLoadStoreUnsignedOffset(instr);
100 
101   if (instr->Rn() == TR) {
102     int64_t offset = instr->ImmLSUnsigned() << instr->SizeLS();
103     std::ostringstream tmp_stream;
104     Thread::DumpThreadOffset<8>(tmp_stream, static_cast<uint32_t>(offset));
105     AppendToOutput(" ; %s", tmp_stream.str().c_str());
106   }
107 }
108 
Dump(std::ostream & os,const uint8_t * begin)109 size_t DisassemblerArm64::Dump(std::ostream& os, const uint8_t* begin) {
110   const vixl::Instruction* instr = reinterpret_cast<const vixl::Instruction*>(begin);
111   decoder.Decode(instr);
112     os << FormatInstructionPointer(begin)
113      << StringPrintf(": %08x\t%s\n", instr->InstructionBits(), disasm.GetOutput());
114   return vixl::kInstructionSize;
115 }
116 
Dump(std::ostream & os,const uint8_t * begin,const uint8_t * end)117 void DisassemblerArm64::Dump(std::ostream& os, const uint8_t* begin, const uint8_t* end) {
118   for (const uint8_t* cur = begin; cur < end; cur += vixl::kInstructionSize) {
119     Dump(os, cur);
120   }
121 }
122 
123 }  // namespace arm64
124 }  // namespace art
125