1//===-- PlatformQemuUser.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 "Plugins/Platform/QemuUser/PlatformQemuUser.h"
10#include "Plugins/Process/gdb-remote/ProcessGDBRemote.h"
11#include "lldb/Core/PluginManager.h"
12#include "lldb/Host/FileSystem.h"
13#include "lldb/Host/ProcessLaunchInfo.h"
14#include "lldb/Interpreter/OptionValueProperties.h"
15#include "lldb/Target/Process.h"
16#include "lldb/Target/Target.h"
17#include "lldb/Utility/LLDBLog.h"
18#include "lldb/Utility/Listener.h"
19#include "lldb/Utility/Log.h"
20
21using namespace lldb;
22using namespace lldb_private;
23
24LLDB_PLUGIN_DEFINE(PlatformQemuUser)
25
26namespace {
27#define LLDB_PROPERTIES_platformqemuuser
28#include "PlatformQemuUserProperties.inc"
29
30enum {
31#define LLDB_PROPERTIES_platformqemuuser
32#include "PlatformQemuUserPropertiesEnum.inc"
33};
34
35class PluginProperties : public Properties {
36public:
37 PluginProperties() {
38 m_collection_sp = std::make_shared<OptionValueProperties>(
39 PlatformQemuUser::GetPluginNameStatic());
40 m_collection_sp->Initialize(g_platformqemuuser_properties);
41 }
42
43 llvm::StringRef GetArchitecture() {
44 return GetPropertyAtIndexAs<llvm::StringRef>(ePropertyArchitecture, "");
45 }
46
47 FileSpec GetEmulatorPath() {
48 return GetPropertyAtIndexAs<FileSpec>(ePropertyEmulatorPath, {});
49 }
50
51 Args GetEmulatorArgs() {
52 Args result;
53 m_collection_sp->GetPropertyAtIndexAsArgs(ePropertyEmulatorArgs, result);
54 return result;
55 }
56
57 Environment GetEmulatorEnvVars() {
58 Args args;
59 m_collection_sp->GetPropertyAtIndexAsArgs(ePropertyEmulatorEnvVars, args);
60 return Environment(args);
61 }
62
63 Environment GetTargetEnvVars() {
64 Args args;
65 m_collection_sp->GetPropertyAtIndexAsArgs(ePropertyTargetEnvVars, args);
66 return Environment(args);
67 }
68};
69
70} // namespace
71
72static PluginProperties &GetGlobalProperties() {
73 static PluginProperties g_settings;
74 return g_settings;
75}
76
77llvm::StringRef PlatformQemuUser::GetPluginDescriptionStatic() {
78 return "Platform for debugging binaries under user mode qemu";
79}
80
81void PlatformQemuUser::Initialize() {
82 PluginManager::RegisterPlugin(
83 name: GetPluginNameStatic(), description: GetPluginDescriptionStatic(),
84 create_callback: PlatformQemuUser::CreateInstance, debugger_init_callback: PlatformQemuUser::DebuggerInitialize);
85}
86
87void PlatformQemuUser::Terminate() {
88 PluginManager::UnregisterPlugin(create_callback: PlatformQemuUser::CreateInstance);
89}
90
91void PlatformQemuUser::DebuggerInitialize(Debugger &debugger) {
92 if (!PluginManager::GetSettingForPlatformPlugin(debugger,
93 setting_name: GetPluginNameStatic())) {
94 PluginManager::CreateSettingForPlatformPlugin(
95 debugger, properties_sp: GetGlobalProperties().GetValueProperties(),
96 description: "Properties for the qemu-user platform plugin.",
97 /*is_global_property=*/true);
98 }
99}
100
101PlatformSP PlatformQemuUser::CreateInstance(bool force, const ArchSpec *arch) {
102 if (force)
103 return PlatformSP(new PlatformQemuUser());
104 return nullptr;
105}
106
107std::vector<ArchSpec>
108PlatformQemuUser::GetSupportedArchitectures(const ArchSpec &process_host_arch) {
109 llvm::Triple triple = HostInfo::GetArchitecture().GetTriple();
110 triple.setEnvironment(llvm::Triple::UnknownEnvironment);
111 triple.setArchName(GetGlobalProperties().GetArchitecture());
112 if (triple.getArch() != llvm::Triple::UnknownArch)
113 return {ArchSpec(triple)};
114 return {};
115}
116
117static auto get_arg_range(const Args &args) {
118 return llvm::make_range(x: args.GetArgumentArrayRef().begin(),
119 y: args.GetArgumentArrayRef().end());
120}
121
122// Returns the emulator environment which result in the desired environment
123// being presented to the emulated process. We want to be careful about
124// preserving the host environment, as it may contain entries (LD_LIBRARY_PATH,
125// for example) needed for the operation of the emulator itself.
126static Environment ComputeLaunchEnvironment(Environment target,
127 Environment host) {
128 std::vector<std::string> set_env;
129 for (const auto &KV : target) {
130 // If the host value differs from the target (or is unset), then set it
131 // through QEMU_SET_ENV. Identical entries will be forwarded automatically.
132 auto host_it = host.find(Key: KV.first());
133 if (host_it == host.end() || host_it->second != KV.second)
134 set_env.push_back(x: Environment::compose(KeyValue: KV));
135 }
136 llvm::sort(C&: set_env);
137
138 std::vector<llvm::StringRef> unset_env;
139 for (const auto &KV : host) {
140 // If the target is missing some host entries, then unset them through
141 // QEMU_UNSET_ENV.
142 if (target.count(Key: KV.first()) == 0)
143 unset_env.push_back(x: KV.first());
144 }
145 llvm::sort(C&: unset_env);
146
147 // The actual QEMU_(UN)SET_ENV variables should not be forwarded to the
148 // target.
149 if (!set_env.empty()) {
150 host["QEMU_SET_ENV"] = llvm::join(R&: set_env, Separator: ",");
151 unset_env.push_back(x: "QEMU_SET_ENV");
152 }
153 if (!unset_env.empty()) {
154 unset_env.push_back(x: "QEMU_UNSET_ENV");
155 host["QEMU_UNSET_ENV"] = llvm::join(R&: unset_env, Separator: ",");
156 }
157 return host;
158}
159
160lldb::ProcessSP PlatformQemuUser::DebugProcess(ProcessLaunchInfo &launch_info,
161 Debugger &debugger,
162 Target &target, Status &error) {
163 Log *log = GetLog(mask: LLDBLog::Platform);
164
165 // If platform.plugin.qemu-user.emulator-path is set, use it.
166 FileSpec qemu = GetGlobalProperties().GetEmulatorPath();
167 // If platform.plugin.qemu-user.emulator-path is not set, build the
168 // executable name from platform.plugin.qemu-user.architecture.
169 if (!qemu) {
170 llvm::StringRef arch = GetGlobalProperties().GetArchitecture();
171 // If platform.plugin.qemu-user.architecture is not set, build the
172 // executable name from the target Triple's ArchName
173 if (arch.empty())
174 arch = target.GetArchitecture().GetTriple().getArchName();
175 qemu.SetPath(("qemu-" + arch).str());
176 }
177 FileSystem::Instance().ResolveExecutableLocation(file_spec&: qemu);
178
179 llvm::SmallString<0> socket_model, socket_path;
180 HostInfo::GetProcessTempDir().GetPath(path&: socket_model);
181 llvm::sys::path::append(path&: socket_model, a: "qemu-%%%%%%%%.socket");
182 do {
183 llvm::sys::fs::createUniquePath(Model: socket_model, ResultPath&: socket_path, MakeAbsolute: false);
184 } while (FileSystem::Instance().Exists(path: socket_path));
185
186 Args args({qemu.GetPath(), "-g", socket_path});
187 if (!launch_info.GetArg0().empty()) {
188 args.AppendArgument(arg_str: "-0");
189 args.AppendArgument(arg_str: launch_info.GetArg0());
190 }
191 args.AppendArguments(rhs: GetGlobalProperties().GetEmulatorArgs());
192 args.AppendArgument(arg_str: "--");
193 args.AppendArgument(arg_str: launch_info.GetExecutableFile().GetPath());
194 for (size_t i = 1; i < launch_info.GetArguments().size(); ++i)
195 args.AppendArgument(arg_str: launch_info.GetArguments()[i].ref());
196
197 LLDB_LOG(log, "{0} -> {1}", get_arg_range(launch_info.GetArguments()),
198 get_arg_range(args));
199
200 launch_info.SetArguments(args, first_arg_is_executable: true);
201
202 Environment emulator_env = Host::GetEnvironment();
203 if (const std::string &sysroot = GetSDKRootDirectory(); !sysroot.empty())
204 emulator_env["QEMU_LD_PREFIX"] = sysroot;
205 for (const auto &KV : GetGlobalProperties().GetEmulatorEnvVars())
206 emulator_env[KV.first()] = KV.second;
207 launch_info.GetEnvironment() = ComputeLaunchEnvironment(
208 target: std::move(launch_info.GetEnvironment()), host: std::move(emulator_env));
209
210 launch_info.SetLaunchInSeparateProcessGroup(true);
211 launch_info.GetFlags().Clear(mask: eLaunchFlagDebug);
212 launch_info.SetMonitorProcessCallback(ProcessLaunchInfo::NoOpMonitorCallback);
213
214 // This is automatically done for host platform in
215 // Target::FinalizeFileActions, but we're not a host platform.
216 llvm::Error Err = launch_info.SetUpPtyRedirection();
217 LLDB_LOG_ERROR(log, std::move(Err), "SetUpPtyRedirection failed: {0}");
218
219 error = Host::LaunchProcess(launch_info);
220 if (error.Fail())
221 return nullptr;
222
223 ProcessSP process_sp = target.CreateProcess(
224 listener_sp: launch_info.GetListener(),
225 plugin_name: process_gdb_remote::ProcessGDBRemote::GetPluginNameStatic(), crash_file: nullptr,
226 can_connect: true);
227 if (!process_sp) {
228 error = Status::FromErrorString(str: "Failed to create GDB process");
229 return nullptr;
230 }
231
232 process_sp->HijackProcessEvents(listener_sp: launch_info.GetHijackListener());
233
234 error = process_sp->ConnectRemote(remote_url: ("unix-connect://" + socket_path).str());
235 if (error.Fail())
236 return nullptr;
237
238 if (launch_info.GetPTY().GetPrimaryFileDescriptor() !=
239 PseudoTerminal::invalid_fd)
240 process_sp->SetSTDIOFileDescriptor(
241 launch_info.GetPTY().ReleasePrimaryFileDescriptor());
242
243 return process_sp;
244}
245
246Environment PlatformQemuUser::GetEnvironment() {
247 Environment env = Host::GetEnvironment();
248 for (const auto &KV : GetGlobalProperties().GetTargetEnvVars())
249 env[KV.first()] = KV.second;
250 return env;
251}
252

source code of lldb/source/Plugins/Platform/QemuUser/PlatformQemuUser.cpp