1 /*
2 * Copyright (C) 2016 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 #include <string.h>
19
20 #include <functional>
21
22 #include <unwindstack/Elf.h>
23 #include <unwindstack/MachineX86_64.h>
24 #include <unwindstack/MapInfo.h>
25 #include <unwindstack/Memory.h>
26 #include <unwindstack/RegsX86_64.h>
27 #include <unwindstack/UcontextX86_64.h>
28 #include <unwindstack/UserX86_64.h>
29
30 namespace unwindstack {
31
RegsX86_64()32 RegsX86_64::RegsX86_64() : RegsImpl<uint64_t>(X86_64_REG_LAST, Location(LOCATION_SP_OFFSET, -8)) {}
33
Arch()34 ArchEnum RegsX86_64::Arch() {
35 return ARCH_X86_64;
36 }
37
pc()38 uint64_t RegsX86_64::pc() {
39 return regs_[X86_64_REG_PC];
40 }
41
sp()42 uint64_t RegsX86_64::sp() {
43 return regs_[X86_64_REG_SP];
44 }
45
set_pc(uint64_t pc)46 void RegsX86_64::set_pc(uint64_t pc) {
47 regs_[X86_64_REG_PC] = pc;
48 }
49
set_sp(uint64_t sp)50 void RegsX86_64::set_sp(uint64_t sp) {
51 regs_[X86_64_REG_SP] = sp;
52 }
53
GetPcAdjustment(uint64_t rel_pc,Elf *)54 uint64_t RegsX86_64::GetPcAdjustment(uint64_t rel_pc, Elf*) {
55 if (rel_pc == 0) {
56 return 0;
57 }
58 return 1;
59 }
60
SetPcFromReturnAddress(Memory * process_memory)61 bool RegsX86_64::SetPcFromReturnAddress(Memory* process_memory) {
62 // Attempt to get the return address from the top of the stack.
63 uint64_t new_pc;
64 if (!process_memory->ReadFully(regs_[X86_64_REG_SP], &new_pc, sizeof(new_pc)) ||
65 new_pc == regs_[X86_64_REG_PC]) {
66 return false;
67 }
68
69 regs_[X86_64_REG_PC] = new_pc;
70 return true;
71 }
72
IterateRegisters(std::function<void (const char *,uint64_t)> fn)73 void RegsX86_64::IterateRegisters(std::function<void(const char*, uint64_t)> fn) {
74 fn("rax", regs_[X86_64_REG_RAX]);
75 fn("rbx", regs_[X86_64_REG_RBX]);
76 fn("rcx", regs_[X86_64_REG_RCX]);
77 fn("rdx", regs_[X86_64_REG_RDX]);
78 fn("r8", regs_[X86_64_REG_R8]);
79 fn("r9", regs_[X86_64_REG_R9]);
80 fn("r10", regs_[X86_64_REG_R10]);
81 fn("r11", regs_[X86_64_REG_R11]);
82 fn("r12", regs_[X86_64_REG_R12]);
83 fn("r13", regs_[X86_64_REG_R13]);
84 fn("r14", regs_[X86_64_REG_R14]);
85 fn("r15", regs_[X86_64_REG_R15]);
86 fn("rdi", regs_[X86_64_REG_RDI]);
87 fn("rsi", regs_[X86_64_REG_RSI]);
88 fn("rbp", regs_[X86_64_REG_RBP]);
89 fn("rsp", regs_[X86_64_REG_RSP]);
90 fn("rip", regs_[X86_64_REG_RIP]);
91 }
92
Read(void * remote_data)93 Regs* RegsX86_64::Read(void* remote_data) {
94 x86_64_user_regs* user = reinterpret_cast<x86_64_user_regs*>(remote_data);
95
96 RegsX86_64* regs = new RegsX86_64();
97 (*regs)[X86_64_REG_RAX] = user->rax;
98 (*regs)[X86_64_REG_RBX] = user->rbx;
99 (*regs)[X86_64_REG_RCX] = user->rcx;
100 (*regs)[X86_64_REG_RDX] = user->rdx;
101 (*regs)[X86_64_REG_R8] = user->r8;
102 (*regs)[X86_64_REG_R9] = user->r9;
103 (*regs)[X86_64_REG_R10] = user->r10;
104 (*regs)[X86_64_REG_R11] = user->r11;
105 (*regs)[X86_64_REG_R12] = user->r12;
106 (*regs)[X86_64_REG_R13] = user->r13;
107 (*regs)[X86_64_REG_R14] = user->r14;
108 (*regs)[X86_64_REG_R15] = user->r15;
109 (*regs)[X86_64_REG_RDI] = user->rdi;
110 (*regs)[X86_64_REG_RSI] = user->rsi;
111 (*regs)[X86_64_REG_RBP] = user->rbp;
112 (*regs)[X86_64_REG_RSP] = user->rsp;
113 (*regs)[X86_64_REG_RIP] = user->rip;
114
115 return regs;
116 }
117
SetFromUcontext(x86_64_ucontext_t * ucontext)118 void RegsX86_64::SetFromUcontext(x86_64_ucontext_t* ucontext) {
119 // R8-R15
120 memcpy(®s_[X86_64_REG_R8], &ucontext->uc_mcontext.r8, 8 * sizeof(uint64_t));
121
122 // Rest of the registers.
123 regs_[X86_64_REG_RDI] = ucontext->uc_mcontext.rdi;
124 regs_[X86_64_REG_RSI] = ucontext->uc_mcontext.rsi;
125 regs_[X86_64_REG_RBP] = ucontext->uc_mcontext.rbp;
126 regs_[X86_64_REG_RBX] = ucontext->uc_mcontext.rbx;
127 regs_[X86_64_REG_RDX] = ucontext->uc_mcontext.rdx;
128 regs_[X86_64_REG_RAX] = ucontext->uc_mcontext.rax;
129 regs_[X86_64_REG_RCX] = ucontext->uc_mcontext.rcx;
130 regs_[X86_64_REG_RSP] = ucontext->uc_mcontext.rsp;
131 regs_[X86_64_REG_RIP] = ucontext->uc_mcontext.rip;
132 }
133
CreateFromUcontext(void * ucontext)134 Regs* RegsX86_64::CreateFromUcontext(void* ucontext) {
135 x86_64_ucontext_t* x86_64_ucontext = reinterpret_cast<x86_64_ucontext_t*>(ucontext);
136
137 RegsX86_64* regs = new RegsX86_64();
138 regs->SetFromUcontext(x86_64_ucontext);
139 return regs;
140 }
141
StepIfSignalHandler(uint64_t rel_pc,Elf * elf,Memory * process_memory)142 bool RegsX86_64::StepIfSignalHandler(uint64_t rel_pc, Elf* elf, Memory* process_memory) {
143 uint64_t data;
144 Memory* elf_memory = elf->memory();
145 // Read from elf memory since it is usually more expensive to read from
146 // process memory.
147 if (!elf_memory->ReadFully(rel_pc, &data, sizeof(data)) || data != 0x0f0000000fc0c748) {
148 return false;
149 }
150
151 uint16_t data2;
152 if (!elf_memory->ReadFully(rel_pc + 8, &data2, sizeof(data2)) || data2 != 0x0f05) {
153 return false;
154 }
155
156 // __restore_rt:
157 // 0x48 0xc7 0xc0 0x0f 0x00 0x00 0x00 mov $0xf,%rax
158 // 0x0f 0x05 syscall
159 // 0x0f nopl 0x0($rax)
160
161 // Read the mcontext data from the stack.
162 // sp points to the ucontext data structure, read only the mcontext part.
163 x86_64_ucontext_t x86_64_ucontext;
164 if (!process_memory->ReadFully(regs_[X86_64_REG_SP] + 0x28, &x86_64_ucontext.uc_mcontext,
165 sizeof(x86_64_mcontext_t))) {
166 return false;
167 }
168 SetFromUcontext(&x86_64_ucontext);
169 return true;
170 }
171
Clone()172 Regs* RegsX86_64::Clone() {
173 return new RegsX86_64(*this);
174 }
175
176 } // namespace unwindstack
177