1 /*
2 * Copyright (C) 2017 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 <stdint.h>
18
19 #include <functional>
20
21 #include <unwindstack/Elf.h>
22 #include <unwindstack/MachineMips64.h>
23 #include <unwindstack/MapInfo.h>
24 #include <unwindstack/Memory.h>
25 #include <unwindstack/RegsMips64.h>
26 #include <unwindstack/UcontextMips64.h>
27 #include <unwindstack/UserMips64.h>
28
29 namespace unwindstack {
30
RegsMips64()31 RegsMips64::RegsMips64()
32 : RegsImpl<uint64_t>(MIPS64_REG_LAST, Location(LOCATION_REGISTER, MIPS64_REG_RA)) {}
33
Arch()34 ArchEnum RegsMips64::Arch() {
35 return ARCH_MIPS64;
36 }
37
pc()38 uint64_t RegsMips64::pc() {
39 return regs_[MIPS64_REG_PC];
40 }
41
sp()42 uint64_t RegsMips64::sp() {
43 return regs_[MIPS64_REG_SP];
44 }
45
set_pc(uint64_t pc)46 void RegsMips64::set_pc(uint64_t pc) {
47 regs_[MIPS64_REG_PC] = pc;
48 }
49
set_sp(uint64_t sp)50 void RegsMips64::set_sp(uint64_t sp) {
51 regs_[MIPS64_REG_SP] = sp;
52 }
53
GetPcAdjustment(uint64_t rel_pc,Elf *)54 uint64_t RegsMips64::GetPcAdjustment(uint64_t rel_pc, Elf*) {
55 if (rel_pc < 8) {
56 return 0;
57 }
58 // For now, just assume no compact branches
59 return 8;
60 }
61
SetPcFromReturnAddress(Memory *)62 bool RegsMips64::SetPcFromReturnAddress(Memory*) {
63 uint64_t ra = regs_[MIPS64_REG_RA];
64 if (regs_[MIPS64_REG_PC] == ra) {
65 return false;
66 }
67
68 regs_[MIPS64_REG_PC] = ra;
69 return true;
70 }
71
IterateRegisters(std::function<void (const char *,uint64_t)> fn)72 void RegsMips64::IterateRegisters(std::function<void(const char*, uint64_t)> fn) {
73 fn("r0", regs_[MIPS64_REG_R0]);
74 fn("r1", regs_[MIPS64_REG_R1]);
75 fn("r2", regs_[MIPS64_REG_R2]);
76 fn("r3", regs_[MIPS64_REG_R3]);
77 fn("r4", regs_[MIPS64_REG_R4]);
78 fn("r5", regs_[MIPS64_REG_R5]);
79 fn("r6", regs_[MIPS64_REG_R6]);
80 fn("r7", regs_[MIPS64_REG_R7]);
81 fn("r8", regs_[MIPS64_REG_R8]);
82 fn("r9", regs_[MIPS64_REG_R9]);
83 fn("r10", regs_[MIPS64_REG_R10]);
84 fn("r11", regs_[MIPS64_REG_R11]);
85 fn("r12", regs_[MIPS64_REG_R12]);
86 fn("r13", regs_[MIPS64_REG_R13]);
87 fn("r14", regs_[MIPS64_REG_R14]);
88 fn("r15", regs_[MIPS64_REG_R15]);
89 fn("r16", regs_[MIPS64_REG_R16]);
90 fn("r17", regs_[MIPS64_REG_R17]);
91 fn("r18", regs_[MIPS64_REG_R18]);
92 fn("r19", regs_[MIPS64_REG_R19]);
93 fn("r20", regs_[MIPS64_REG_R20]);
94 fn("r21", regs_[MIPS64_REG_R21]);
95 fn("r22", regs_[MIPS64_REG_R22]);
96 fn("r23", regs_[MIPS64_REG_R23]);
97 fn("r24", regs_[MIPS64_REG_R24]);
98 fn("r25", regs_[MIPS64_REG_R25]);
99 fn("r26", regs_[MIPS64_REG_R26]);
100 fn("r27", regs_[MIPS64_REG_R27]);
101 fn("r28", regs_[MIPS64_REG_R28]);
102 fn("sp", regs_[MIPS64_REG_SP]);
103 fn("r30", regs_[MIPS64_REG_R30]);
104 fn("ra", regs_[MIPS64_REG_RA]);
105 fn("pc", regs_[MIPS64_REG_PC]);
106 }
107
Read(void * remote_data)108 Regs* RegsMips64::Read(void* remote_data) {
109 mips64_user_regs* user = reinterpret_cast<mips64_user_regs*>(remote_data);
110 RegsMips64* regs = new RegsMips64();
111 uint64_t* reg_data = reinterpret_cast<uint64_t*>(regs->RawData());
112
113 memcpy(regs->RawData(), &user->regs[MIPS64_EF_R0], (MIPS64_REG_R31 + 1) * sizeof(uint64_t));
114
115 reg_data[MIPS64_REG_PC] = user->regs[MIPS64_EF_CP0_EPC];
116 return regs;
117 }
118
CreateFromUcontext(void * ucontext)119 Regs* RegsMips64::CreateFromUcontext(void* ucontext) {
120 mips64_ucontext_t* mips64_ucontext = reinterpret_cast<mips64_ucontext_t*>(ucontext);
121
122 RegsMips64* regs = new RegsMips64();
123 // Copy 64 bit sc_regs over to 64 bit regs
124 memcpy(regs->RawData(), &mips64_ucontext->uc_mcontext.sc_regs[0], 32 * sizeof(uint64_t));
125 (*regs)[MIPS64_REG_PC] = mips64_ucontext->uc_mcontext.sc_pc;
126 return regs;
127 }
128
StepIfSignalHandler(uint64_t rel_pc,Elf * elf,Memory * process_memory)129 bool RegsMips64::StepIfSignalHandler(uint64_t rel_pc, Elf* elf, Memory* process_memory) {
130 uint64_t data;
131 Memory* elf_memory = elf->memory();
132 // Read from elf memory since it is usually more expensive to read from
133 // process memory.
134 if (!elf_memory->Read(rel_pc, &data, sizeof(data))) {
135 return false;
136 }
137
138 // Look for the kernel sigreturn function.
139 // __vdso_rt_sigreturn:
140 // 0x2402145b li v0, 0x145b
141 // 0x0000000c syscall
142 if (data != 0x0000000c2402145bULL) {
143 return false;
144 }
145
146 // vdso_rt_sigreturn => read rt_sigframe
147 // offset = siginfo offset + sizeof(siginfo) + uc_mcontext offset
148 // read 64 bit sc_regs[32] from stack into 64 bit regs_
149 uint64_t sp = regs_[MIPS64_REG_SP];
150 if (!process_memory->Read(sp + 24 + 128 + 40, regs_.data(),
151 sizeof(uint64_t) * (MIPS64_REG_LAST - 1))) {
152 return false;
153 }
154
155 // offset = siginfo offset + sizeof(siginfo) + uc_mcontext offset + sc_pc offset
156 // read 64 bit sc_pc from stack into 64 bit regs_[MIPS64_REG_PC]
157 if (!process_memory->Read(sp + 24 + 128 + 40 + 576, ®s_[MIPS64_REG_PC], sizeof(uint64_t))) {
158 return false;
159 }
160 return true;
161 }
162
Clone()163 Regs* RegsMips64::Clone() {
164 return new RegsMips64(*this);
165 }
166
167 } // namespace unwindstack
168