1 //===-- RegisterContextWindows_x86.cpp --------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Host/windows/HostThreadWindows.h"
10 #include "lldb/Host/windows/windows.h"
11 #include "lldb/Utility/RegisterValue.h"
12 #include "lldb/Utility/Status.h"
13 #include "lldb/lldb-private-types.h"
14 
15 #include "ProcessWindowsLog.h"
16 #include "RegisterContextWindows_x86.h"
17 #include "Plugins/Process/Utility/RegisterContext_x86.h"
18 #include "TargetThreadWindows.h"
19 #include "Plugins/Process/Utility/lldb-x86-register-enums.h"
20 
21 #include "llvm/ADT/STLExtras.h"
22 
23 using namespace lldb;
24 using namespace lldb_private;
25 
26 #define DEFINE_GPR(reg, alt) #reg, alt, 4, 0, eEncodingUint, eFormatHexUppercase
27 #define DEFINE_GPR_BIN(reg, alt) #reg, alt, 4, 0, eEncodingUint, eFormatBinary
28 
29 namespace {
30 
31 // This enum defines the layout of the global RegisterInfo array.  This is
32 // necessary because lldb register sets are defined in terms of indices into
33 // the register array. As such, the order of RegisterInfos defined in global
34 // registers array must match the order defined here. When defining the
35 // register set layouts, these values can appear in an arbitrary order, and
36 // that determines the order that register values are displayed in a dump.
37 enum RegisterIndex {
38   eRegisterIndexEax,
39   eRegisterIndexEbx,
40   eRegisterIndexEcx,
41   eRegisterIndexEdx,
42   eRegisterIndexEdi,
43   eRegisterIndexEsi,
44   eRegisterIndexEbp,
45   eRegisterIndexEsp,
46   eRegisterIndexEip,
47   eRegisterIndexEflags
48 };
49 
50 // Array of all register information supported by Windows x86
51 RegisterInfo g_register_infos[] = {
52     //  Macro auto defines most stuff   eh_frame                DWARF
53     //  GENERIC                    GDB                   LLDB
54     //  VALUE REGS    INVALIDATE REGS
55     //  ==============================  =======================
56     //  ===================  =========================  ===================
57     //  =================  ==========    ===============
58     {DEFINE_GPR(eax, nullptr),
59      {ehframe_eax_i386, dwarf_eax_i386, LLDB_INVALID_REGNUM,
60       LLDB_INVALID_REGNUM, lldb_eax_i386},
61      nullptr,
62      nullptr,
63      nullptr,
64      0u},
65     {DEFINE_GPR(ebx, nullptr),
66      {ehframe_ebx_i386, dwarf_ebx_i386, LLDB_INVALID_REGNUM,
67       LLDB_INVALID_REGNUM, lldb_ebx_i386},
68      nullptr,
69      nullptr,
70      nullptr,
71      0u},
72     {DEFINE_GPR(ecx, nullptr),
73      {ehframe_ecx_i386, dwarf_ecx_i386, LLDB_INVALID_REGNUM,
74       LLDB_INVALID_REGNUM, lldb_ecx_i386},
75      nullptr,
76      nullptr,
77      nullptr,
78      0u},
79     {DEFINE_GPR(edx, nullptr),
80      {ehframe_edx_i386, dwarf_edx_i386, LLDB_INVALID_REGNUM,
81       LLDB_INVALID_REGNUM, lldb_edx_i386},
82      nullptr,
83      nullptr,
84      nullptr,
85      0u},
86     {DEFINE_GPR(edi, nullptr),
87      {ehframe_edi_i386, dwarf_edi_i386, LLDB_INVALID_REGNUM,
88       LLDB_INVALID_REGNUM, lldb_edi_i386},
89      nullptr,
90      nullptr,
91      nullptr,
92      0u},
93     {DEFINE_GPR(esi, nullptr),
94      {ehframe_esi_i386, dwarf_esi_i386, LLDB_INVALID_REGNUM,
95       LLDB_INVALID_REGNUM, lldb_esi_i386},
96      nullptr,
97      nullptr,
98      nullptr,
99      0u},
100     {DEFINE_GPR(ebp, "fp"),
101      {ehframe_ebp_i386, dwarf_ebp_i386, LLDB_REGNUM_GENERIC_FP,
102       LLDB_INVALID_REGNUM, lldb_ebp_i386},
103      nullptr,
104      nullptr,
105      nullptr,
106      0u},
107     {DEFINE_GPR(esp, "sp"),
108      {ehframe_esp_i386, dwarf_esp_i386, LLDB_REGNUM_GENERIC_SP,
109       LLDB_INVALID_REGNUM, lldb_esp_i386},
110      nullptr,
111      nullptr,
112      nullptr,
113      0u},
114     {DEFINE_GPR(eip, "pc"),
115      {ehframe_eip_i386, dwarf_eip_i386, LLDB_REGNUM_GENERIC_PC,
116       LLDB_INVALID_REGNUM, lldb_eip_i386},
117      nullptr,
118      nullptr,
119      nullptr,
120      0u},
121     {DEFINE_GPR_BIN(eflags, "flags"),
122      {ehframe_eflags_i386, dwarf_eflags_i386, LLDB_REGNUM_GENERIC_FLAGS,
123       LLDB_INVALID_REGNUM, lldb_eflags_i386},
124      nullptr,
125      nullptr,
126      nullptr,
127      0u},
128 };
129 static size_t k_num_register_infos = llvm::array_lengthof(g_register_infos);
130 
131 // Array of lldb register numbers used to define the set of all General Purpose
132 // Registers
133 uint32_t g_gpr_reg_indices[] = {eRegisterIndexEax, eRegisterIndexEbx,
134                                 eRegisterIndexEcx, eRegisterIndexEdx,
135                                 eRegisterIndexEdi, eRegisterIndexEsi,
136                                 eRegisterIndexEbp, eRegisterIndexEsp,
137                                 eRegisterIndexEip, eRegisterIndexEflags};
138 
139 RegisterSet g_register_sets[] = {
140     {"General Purpose Registers", "gpr",
141      llvm::array_lengthof(g_gpr_reg_indices), g_gpr_reg_indices},
142 };
143 }
144 
145 // Constructors and Destructors
146 RegisterContextWindows_x86::RegisterContextWindows_x86(
147     Thread &thread, uint32_t concrete_frame_idx)
148     : RegisterContextWindows(thread, concrete_frame_idx) {}
149 
150 RegisterContextWindows_x86::~RegisterContextWindows_x86() {}
151 
152 size_t RegisterContextWindows_x86::GetRegisterCount() {
153   return llvm::array_lengthof(g_register_infos);
154 }
155 
156 const RegisterInfo *
157 RegisterContextWindows_x86::GetRegisterInfoAtIndex(size_t reg) {
158   if (reg < k_num_register_infos)
159     return &g_register_infos[reg];
160   return NULL;
161 }
162 
163 size_t RegisterContextWindows_x86::GetRegisterSetCount() {
164   return llvm::array_lengthof(g_register_sets);
165 }
166 
167 const RegisterSet *RegisterContextWindows_x86::GetRegisterSet(size_t reg_set) {
168   return &g_register_sets[reg_set];
169 }
170 
171 bool RegisterContextWindows_x86::ReadRegister(const RegisterInfo *reg_info,
172                                               RegisterValue &reg_value) {
173   if (!CacheAllRegisterValues())
174     return false;
175 
176   if (reg_info == nullptr)
177     return false;
178 
179   uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
180   switch (reg) {
181   case lldb_eax_i386:
182     return ReadRegisterHelper(CONTEXT_INTEGER, "EAX", m_context.Eax, reg_value);
183   case lldb_ebx_i386:
184     return ReadRegisterHelper(CONTEXT_INTEGER, "EBX", m_context.Ebx, reg_value);
185   case lldb_ecx_i386:
186     return ReadRegisterHelper(CONTEXT_INTEGER, "ECX", m_context.Ecx, reg_value);
187   case lldb_edx_i386:
188     return ReadRegisterHelper(CONTEXT_INTEGER, "EDX", m_context.Edx, reg_value);
189   case lldb_edi_i386:
190     return ReadRegisterHelper(CONTEXT_INTEGER, "EDI", m_context.Edi, reg_value);
191   case lldb_esi_i386:
192     return ReadRegisterHelper(CONTEXT_INTEGER, "ESI", m_context.Esi, reg_value);
193   case lldb_ebp_i386:
194     return ReadRegisterHelper(CONTEXT_CONTROL, "EBP", m_context.Ebp, reg_value);
195   case lldb_esp_i386:
196     return ReadRegisterHelper(CONTEXT_CONTROL, "ESP", m_context.Esp, reg_value);
197   case lldb_eip_i386:
198     return ReadRegisterHelper(CONTEXT_CONTROL, "EIP", m_context.Eip, reg_value);
199   case lldb_eflags_i386:
200     return ReadRegisterHelper(CONTEXT_CONTROL, "EFLAGS", m_context.EFlags,
201                               reg_value);
202   default:
203     Log *log = ProcessWindowsLog::GetLogIfAny(WINDOWS_LOG_REGISTERS);
204     LLDB_LOG(log, "Requested unknown register {0}", reg);
205     break;
206   }
207   return false;
208 }
209 
210 bool RegisterContextWindows_x86::WriteRegister(const RegisterInfo *reg_info,
211                                                const RegisterValue &reg_value) {
212   // Since we cannot only write a single register value to the inferior, we
213   // need to make sure our cached copy of the register values are fresh.
214   // Otherwise when writing EAX, for example, we may also overwrite some other
215   // register with a stale value.
216   if (!CacheAllRegisterValues())
217     return false;
218 
219   Log *log = ProcessWindowsLog::GetLogIfAny(WINDOWS_LOG_REGISTERS);
220   uint32_t reg = reg_info->kinds[eRegisterKindLLDB];
221   switch (reg) {
222   case lldb_eax_i386:
223     LLDB_LOG(log, "Write value {0:x} to EAX", reg_value.GetAsUInt32());
224     m_context.Eax = reg_value.GetAsUInt32();
225     break;
226   case lldb_ebx_i386:
227     LLDB_LOG(log, "Write value {0:x} to EBX", reg_value.GetAsUInt32());
228     m_context.Ebx = reg_value.GetAsUInt32();
229     break;
230   case lldb_ecx_i386:
231     LLDB_LOG(log, "Write value {0:x} to ECX", reg_value.GetAsUInt32());
232     m_context.Ecx = reg_value.GetAsUInt32();
233     break;
234   case lldb_edx_i386:
235     LLDB_LOG(log, "Write value {0:x} to EDX", reg_value.GetAsUInt32());
236     m_context.Edx = reg_value.GetAsUInt32();
237     break;
238   case lldb_edi_i386:
239     LLDB_LOG(log, "Write value {0:x} to EDI", reg_value.GetAsUInt32());
240     m_context.Edi = reg_value.GetAsUInt32();
241     break;
242   case lldb_esi_i386:
243     LLDB_LOG(log, "Write value {0:x} to ESI", reg_value.GetAsUInt32());
244     m_context.Esi = reg_value.GetAsUInt32();
245     break;
246   case lldb_ebp_i386:
247     LLDB_LOG(log, "Write value {0:x} to EBP", reg_value.GetAsUInt32());
248     m_context.Ebp = reg_value.GetAsUInt32();
249     break;
250   case lldb_esp_i386:
251     LLDB_LOG(log, "Write value {0:x} to ESP", reg_value.GetAsUInt32());
252     m_context.Esp = reg_value.GetAsUInt32();
253     break;
254   case lldb_eip_i386:
255     LLDB_LOG(log, "Write value {0:x} to EIP", reg_value.GetAsUInt32());
256     m_context.Eip = reg_value.GetAsUInt32();
257     break;
258   case lldb_eflags_i386:
259     LLDB_LOG(log, "Write value {0:x} to EFLAGS", reg_value.GetAsUInt32());
260     m_context.EFlags = reg_value.GetAsUInt32();
261     break;
262   default:
263     LLDB_LOG(log, "Write value {0:x} to unknown register {1}",
264              reg_value.GetAsUInt32(), reg);
265   }
266 
267   // Physically update the registers in the target process.
268   TargetThreadWindows &wthread = static_cast<TargetThreadWindows &>(m_thread);
269   return ::SetThreadContext(
270       wthread.GetHostThread().GetNativeThread().GetSystemHandle(), &m_context);
271 }
272 
273 bool RegisterContextWindows_x86::ReadRegisterHelper(
274     DWORD flags_required, const char *reg_name, DWORD value,
275     RegisterValue &reg_value) const {
276   Log *log = ProcessWindowsLog::GetLogIfAny(WINDOWS_LOG_REGISTERS);
277   if ((m_context.ContextFlags & flags_required) != flags_required) {
278     LLDB_LOG(log, "Thread context doesn't have {0}", reg_name);
279     return false;
280   }
281   LLDB_LOG(log, "Read value {0:x} from {1}", value, reg_name);
282   reg_value.SetUInt32(value);
283   return true;
284 }
285