1 //===-- NativeRegisterContextLinux.cpp ------------------------------------===//
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 "NativeRegisterContextLinux.h"
10
11 #include "lldb/Host/common/NativeProcessProtocol.h"
12 #include "lldb/Host/common/NativeThreadProtocol.h"
13 #include "lldb/Host/linux/Ptrace.h"
14 #include "lldb/Utility/RegisterValue.h"
15
16 #include "Plugins/Process/Linux/NativeProcessLinux.h"
17 #include "Plugins/Process/POSIX/ProcessPOSIXLog.h"
18
19 using namespace lldb_private;
20 using namespace lldb_private::process_linux;
21
GetByteOrder() const22 lldb::ByteOrder NativeRegisterContextLinux::GetByteOrder() const {
23 return m_thread.GetProcess().GetByteOrder();
24 }
25
ReadRegisterRaw(uint32_t reg_index,RegisterValue & reg_value)26 Status NativeRegisterContextLinux::ReadRegisterRaw(uint32_t reg_index,
27 RegisterValue ®_value) {
28 const RegisterInfo *const reg_info = GetRegisterInfoAtIndex(reg_index);
29 if (!reg_info)
30 return Status("register %" PRIu32 " not found", reg_index);
31
32 return DoReadRegisterValue(GetPtraceOffset(reg_index), reg_info->name,
33 reg_info->byte_size, reg_value);
34 }
35
36 Status
WriteRegisterRaw(uint32_t reg_index,const RegisterValue & reg_value)37 NativeRegisterContextLinux::WriteRegisterRaw(uint32_t reg_index,
38 const RegisterValue ®_value) {
39 uint32_t reg_to_write = reg_index;
40 RegisterValue value_to_write = reg_value;
41
42 // Check if this is a subregister of a full register.
43 const RegisterInfo *reg_info = GetRegisterInfoAtIndex(reg_index);
44 if (reg_info->invalidate_regs &&
45 (reg_info->invalidate_regs[0] != LLDB_INVALID_REGNUM)) {
46 Status error;
47
48 RegisterValue full_value;
49 uint32_t full_reg = reg_info->invalidate_regs[0];
50 const RegisterInfo *full_reg_info = GetRegisterInfoAtIndex(full_reg);
51
52 // Read the full register.
53 error = ReadRegister(full_reg_info, full_value);
54 if (error.Fail())
55 return error;
56
57 lldb::ByteOrder byte_order = GetByteOrder();
58 uint8_t dst[RegisterValue::kMaxRegisterByteSize];
59
60 // Get the bytes for the full register.
61 const uint32_t dest_size = full_value.GetAsMemoryData(
62 full_reg_info, dst, sizeof(dst), byte_order, error);
63 if (error.Success() && dest_size) {
64 uint8_t src[RegisterValue::kMaxRegisterByteSize];
65
66 // Get the bytes for the source data.
67 const uint32_t src_size = reg_value.GetAsMemoryData(
68 reg_info, src, sizeof(src), byte_order, error);
69 if (error.Success() && src_size && (src_size < dest_size)) {
70 // Copy the src bytes to the destination.
71 memcpy(dst + (reg_info->byte_offset & 0x1), src, src_size);
72 // Set this full register as the value to write.
73 value_to_write.SetBytes(dst, full_value.GetByteSize(), byte_order);
74 value_to_write.SetType(full_reg_info);
75 reg_to_write = full_reg;
76 }
77 }
78 }
79
80 const RegisterInfo *const register_to_write_info_p =
81 GetRegisterInfoAtIndex(reg_to_write);
82 assert(register_to_write_info_p &&
83 "register to write does not have valid RegisterInfo");
84 if (!register_to_write_info_p)
85 return Status("NativeRegisterContextLinux::%s failed to get RegisterInfo "
86 "for write register index %" PRIu32,
87 __FUNCTION__, reg_to_write);
88
89 return DoWriteRegisterValue(GetPtraceOffset(reg_index), reg_info->name,
90 reg_value);
91 }
92
ReadGPR()93 Status NativeRegisterContextLinux::ReadGPR() {
94 return NativeProcessLinux::PtraceWrapper(
95 PTRACE_GETREGS, m_thread.GetID(), nullptr, GetGPRBuffer(), GetGPRSize());
96 }
97
WriteGPR()98 Status NativeRegisterContextLinux::WriteGPR() {
99 return NativeProcessLinux::PtraceWrapper(
100 PTRACE_SETREGS, m_thread.GetID(), nullptr, GetGPRBuffer(), GetGPRSize());
101 }
102
ReadFPR()103 Status NativeRegisterContextLinux::ReadFPR() {
104 return NativeProcessLinux::PtraceWrapper(PTRACE_GETFPREGS, m_thread.GetID(),
105 nullptr, GetFPRBuffer(),
106 GetFPRSize());
107 }
108
WriteFPR()109 Status NativeRegisterContextLinux::WriteFPR() {
110 return NativeProcessLinux::PtraceWrapper(PTRACE_SETFPREGS, m_thread.GetID(),
111 nullptr, GetFPRBuffer(),
112 GetFPRSize());
113 }
114
ReadRegisterSet(void * buf,size_t buf_size,unsigned int regset)115 Status NativeRegisterContextLinux::ReadRegisterSet(void *buf, size_t buf_size,
116 unsigned int regset) {
117 return NativeProcessLinux::PtraceWrapper(PTRACE_GETREGSET, m_thread.GetID(),
118 static_cast<void *>(®set), buf,
119 buf_size);
120 }
121
WriteRegisterSet(void * buf,size_t buf_size,unsigned int regset)122 Status NativeRegisterContextLinux::WriteRegisterSet(void *buf, size_t buf_size,
123 unsigned int regset) {
124 return NativeProcessLinux::PtraceWrapper(PTRACE_SETREGSET, m_thread.GetID(),
125 static_cast<void *>(®set), buf,
126 buf_size);
127 }
128
DoReadRegisterValue(uint32_t offset,const char * reg_name,uint32_t size,RegisterValue & value)129 Status NativeRegisterContextLinux::DoReadRegisterValue(uint32_t offset,
130 const char *reg_name,
131 uint32_t size,
132 RegisterValue &value) {
133 Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_REGISTERS));
134
135 long data;
136 Status error = NativeProcessLinux::PtraceWrapper(
137 PTRACE_PEEKUSER, m_thread.GetID(), reinterpret_cast<void *>(offset),
138 nullptr, 0, &data);
139
140 if (error.Success())
141 // First cast to an unsigned of the same size to avoid sign extension.
142 value.SetUInt(static_cast<unsigned long>(data), size);
143
144 LLDB_LOG(log, "{0}: {1:x}", reg_name, data);
145 return error;
146 }
147
DoWriteRegisterValue(uint32_t offset,const char * reg_name,const RegisterValue & value)148 Status NativeRegisterContextLinux::DoWriteRegisterValue(
149 uint32_t offset, const char *reg_name, const RegisterValue &value) {
150 Log *log(ProcessPOSIXLog::GetLogIfAllCategoriesSet(POSIX_LOG_REGISTERS));
151
152 void *buf = reinterpret_cast<void *>(value.GetAsUInt64());
153 LLDB_LOG(log, "{0}: {1}", reg_name, buf);
154
155 return NativeProcessLinux::PtraceWrapper(
156 PTRACE_POKEUSER, m_thread.GetID(), reinterpret_cast<void *>(offset), buf);
157 }
158