1 //===-- UnixSignals.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 "lldb/Target/UnixSignals.h"
10 #include "Plugins/Process/Utility/FreeBSDSignals.h"
11 #include "Plugins/Process/Utility/LinuxSignals.h"
12 #include "Plugins/Process/Utility/MipsLinuxSignals.h"
13 #include "Plugins/Process/Utility/NetBSDSignals.h"
14 #include "lldb/Host/HostInfo.h"
15 #include "lldb/Host/StringConvert.h"
16 #include "lldb/Utility/ArchSpec.h"
17 
18 using namespace lldb_private;
19 
20 UnixSignals::Signal::Signal(const char *name, bool default_suppress,
21                             bool default_stop, bool default_notify,
22                             const char *description, const char *alias)
23     : m_name(name), m_alias(alias), m_description(),
24       m_suppress(default_suppress), m_stop(default_stop),
25       m_notify(default_notify) {
26   if (description)
27     m_description.assign(description);
28 }
29 
30 lldb::UnixSignalsSP UnixSignals::Create(const ArchSpec &arch) {
31   const auto &triple = arch.GetTriple();
32   switch (triple.getOS()) {
33   case llvm::Triple::Linux: {
34     switch (triple.getArch()) {
35     case llvm::Triple::mips:
36     case llvm::Triple::mipsel:
37     case llvm::Triple::mips64:
38     case llvm::Triple::mips64el:
39       return std::make_shared<MipsLinuxSignals>();
40     default:
41       return std::make_shared<LinuxSignals>();
42     }
43   }
44   case llvm::Triple::FreeBSD:
45   case llvm::Triple::OpenBSD:
46     return std::make_shared<FreeBSDSignals>();
47   case llvm::Triple::NetBSD:
48     return std::make_shared<NetBSDSignals>();
49   default:
50     return std::make_shared<UnixSignals>();
51   }
52 }
53 
54 lldb::UnixSignalsSP UnixSignals::CreateForHost() {
55   static lldb::UnixSignalsSP s_unix_signals_sp =
56       Create(HostInfo::GetArchitecture());
57   return s_unix_signals_sp;
58 }
59 
60 // UnixSignals constructor
61 UnixSignals::UnixSignals() { Reset(); }
62 
63 UnixSignals::UnixSignals(const UnixSignals &rhs) : m_signals(rhs.m_signals) {}
64 
65 UnixSignals::~UnixSignals() = default;
66 
67 void UnixSignals::Reset() {
68   // This builds one standard set of Unix Signals. If yours aren't quite in
69   // this order, you can either subclass this class, and use Add & Remove to
70   // change them or you can subclass and build them afresh in your constructor.
71   //
72   // Note: the signals below are the Darwin signals. Do not change these!
73 
74   m_signals.clear();
75 
76   // clang-format off
77   //        SIGNO   NAME            SUPPRESS  STOP    NOTIFY  DESCRIPTION
78   //        ======  ==============  ========  ======  ======  ===================================================
79   AddSignal(1,      "SIGHUP",       false,    true,   true,   "hangup");
80   AddSignal(2,      "SIGINT",       true,     true,   true,   "interrupt");
81   AddSignal(3,      "SIGQUIT",      false,    true,   true,   "quit");
82   AddSignal(4,      "SIGILL",       false,    true,   true,   "illegal instruction");
83   AddSignal(5,      "SIGTRAP",      true,     true,   true,   "trace trap (not reset when caught)");
84   AddSignal(6,      "SIGABRT",      false,    true,   true,   "abort()");
85   AddSignal(7,      "SIGEMT",       false,    true,   true,   "pollable event");
86   AddSignal(8,      "SIGFPE",       false,    true,   true,   "floating point exception");
87   AddSignal(9,      "SIGKILL",      false,    true,   true,   "kill");
88   AddSignal(10,     "SIGBUS",       false,    true,   true,   "bus error");
89   AddSignal(11,     "SIGSEGV",      false,    true,   true,   "segmentation violation");
90   AddSignal(12,     "SIGSYS",       false,    true,   true,   "bad argument to system call");
91   AddSignal(13,     "SIGPIPE",      false,    false,  false,  "write on a pipe with no one to read it");
92   AddSignal(14,     "SIGALRM",      false,    false,  false,  "alarm clock");
93   AddSignal(15,     "SIGTERM",      false,    true,   true,   "software termination signal from kill");
94   AddSignal(16,     "SIGURG",       false,    false,  false,  "urgent condition on IO channel");
95   AddSignal(17,     "SIGSTOP",      true,     true,   true,   "sendable stop signal not from tty");
96   AddSignal(18,     "SIGTSTP",      false,    true,   true,   "stop signal from tty");
97   AddSignal(19,     "SIGCONT",      false,    false,  true,   "continue a stopped process");
98   AddSignal(20,     "SIGCHLD",      false,    false,  false,  "to parent on child stop or exit");
99   AddSignal(21,     "SIGTTIN",      false,    true,   true,   "to readers process group upon background tty read");
100   AddSignal(22,     "SIGTTOU",      false,    true,   true,   "to readers process group upon background tty write");
101   AddSignal(23,     "SIGIO",        false,    false,  false,  "input/output possible signal");
102   AddSignal(24,     "SIGXCPU",      false,    true,   true,   "exceeded CPU time limit");
103   AddSignal(25,     "SIGXFSZ",      false,    true,   true,   "exceeded file size limit");
104   AddSignal(26,     "SIGVTALRM",    false,    false,  false,  "virtual time alarm");
105   AddSignal(27,     "SIGPROF",      false,    false,  false,  "profiling time alarm");
106   AddSignal(28,     "SIGWINCH",     false,    false,  false,  "window size changes");
107   AddSignal(29,     "SIGINFO",      false,    true,   true,   "information request");
108   AddSignal(30,     "SIGUSR1",      false,    true,   true,   "user defined signal 1");
109   AddSignal(31,     "SIGUSR2",      false,    true,   true,   "user defined signal 2");
110   // clang-format on
111 }
112 
113 void UnixSignals::AddSignal(int signo, const char *name, bool default_suppress,
114                             bool default_stop, bool default_notify,
115                             const char *description, const char *alias) {
116   Signal new_signal(name, default_suppress, default_stop, default_notify,
117                     description, alias);
118   m_signals.insert(std::make_pair(signo, new_signal));
119   ++m_version;
120 }
121 
122 void UnixSignals::RemoveSignal(int signo) {
123   collection::iterator pos = m_signals.find(signo);
124   if (pos != m_signals.end())
125     m_signals.erase(pos);
126   ++m_version;
127 }
128 
129 const char *UnixSignals::GetSignalAsCString(int signo) const {
130   collection::const_iterator pos = m_signals.find(signo);
131   if (pos == m_signals.end())
132     return nullptr;
133   else
134     return pos->second.m_name.GetCString();
135 }
136 
137 bool UnixSignals::SignalIsValid(int32_t signo) const {
138   return m_signals.find(signo) != m_signals.end();
139 }
140 
141 ConstString UnixSignals::GetShortName(ConstString name) const {
142   if (name)
143     return ConstString(name.GetStringRef().substr(3)); // Remove "SIG" from name
144   return name;
145 }
146 
147 int32_t UnixSignals::GetSignalNumberFromName(const char *name) const {
148   ConstString const_name(name);
149 
150   collection::const_iterator pos, end = m_signals.end();
151   for (pos = m_signals.begin(); pos != end; pos++) {
152     if ((const_name == pos->second.m_name) ||
153         (const_name == pos->second.m_alias) ||
154         (const_name == GetShortName(pos->second.m_name)) ||
155         (const_name == GetShortName(pos->second.m_alias)))
156       return pos->first;
157   }
158 
159   const int32_t signo =
160       StringConvert::ToSInt32(name, LLDB_INVALID_SIGNAL_NUMBER, 0);
161   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
162     return signo;
163   return LLDB_INVALID_SIGNAL_NUMBER;
164 }
165 
166 int32_t UnixSignals::GetFirstSignalNumber() const {
167   if (m_signals.empty())
168     return LLDB_INVALID_SIGNAL_NUMBER;
169 
170   return (*m_signals.begin()).first;
171 }
172 
173 int32_t UnixSignals::GetNextSignalNumber(int32_t current_signal) const {
174   collection::const_iterator pos = m_signals.find(current_signal);
175   collection::const_iterator end = m_signals.end();
176   if (pos == end)
177     return LLDB_INVALID_SIGNAL_NUMBER;
178   else {
179     pos++;
180     if (pos == end)
181       return LLDB_INVALID_SIGNAL_NUMBER;
182     else
183       return pos->first;
184   }
185 }
186 
187 const char *UnixSignals::GetSignalInfo(int32_t signo, bool &should_suppress,
188                                        bool &should_stop,
189                                        bool &should_notify) const {
190   collection::const_iterator pos = m_signals.find(signo);
191   if (pos == m_signals.end())
192     return nullptr;
193   else {
194     const Signal &signal = pos->second;
195     should_suppress = signal.m_suppress;
196     should_stop = signal.m_stop;
197     should_notify = signal.m_notify;
198     return signal.m_name.AsCString("");
199   }
200 }
201 
202 bool UnixSignals::GetShouldSuppress(int signo) const {
203   collection::const_iterator pos = m_signals.find(signo);
204   if (pos != m_signals.end())
205     return pos->second.m_suppress;
206   return false;
207 }
208 
209 bool UnixSignals::SetShouldSuppress(int signo, bool value) {
210   collection::iterator pos = m_signals.find(signo);
211   if (pos != m_signals.end()) {
212     pos->second.m_suppress = value;
213     ++m_version;
214     return true;
215   }
216   return false;
217 }
218 
219 bool UnixSignals::SetShouldSuppress(const char *signal_name, bool value) {
220   const int32_t signo = GetSignalNumberFromName(signal_name);
221   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
222     return SetShouldSuppress(signo, value);
223   return false;
224 }
225 
226 bool UnixSignals::GetShouldStop(int signo) const {
227   collection::const_iterator pos = m_signals.find(signo);
228   if (pos != m_signals.end())
229     return pos->second.m_stop;
230   return false;
231 }
232 
233 bool UnixSignals::SetShouldStop(int signo, bool value) {
234   collection::iterator pos = m_signals.find(signo);
235   if (pos != m_signals.end()) {
236     pos->second.m_stop = value;
237     ++m_version;
238     return true;
239   }
240   return false;
241 }
242 
243 bool UnixSignals::SetShouldStop(const char *signal_name, bool value) {
244   const int32_t signo = GetSignalNumberFromName(signal_name);
245   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
246     return SetShouldStop(signo, value);
247   return false;
248 }
249 
250 bool UnixSignals::GetShouldNotify(int signo) const {
251   collection::const_iterator pos = m_signals.find(signo);
252   if (pos != m_signals.end())
253     return pos->second.m_notify;
254   return false;
255 }
256 
257 bool UnixSignals::SetShouldNotify(int signo, bool value) {
258   collection::iterator pos = m_signals.find(signo);
259   if (pos != m_signals.end()) {
260     pos->second.m_notify = value;
261     ++m_version;
262     return true;
263   }
264   return false;
265 }
266 
267 bool UnixSignals::SetShouldNotify(const char *signal_name, bool value) {
268   const int32_t signo = GetSignalNumberFromName(signal_name);
269   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
270     return SetShouldNotify(signo, value);
271   return false;
272 }
273 
274 int32_t UnixSignals::GetNumSignals() const { return m_signals.size(); }
275 
276 int32_t UnixSignals::GetSignalAtIndex(int32_t index) const {
277   if (index < 0 || m_signals.size() <= static_cast<size_t>(index))
278     return LLDB_INVALID_SIGNAL_NUMBER;
279   auto it = m_signals.begin();
280   std::advance(it, index);
281   return it->first;
282 }
283 
284 uint64_t UnixSignals::GetVersion() const { return m_version; }
285 
286 std::vector<int32_t>
287 UnixSignals::GetFilteredSignals(llvm::Optional<bool> should_suppress,
288                                 llvm::Optional<bool> should_stop,
289                                 llvm::Optional<bool> should_notify) {
290   std::vector<int32_t> result;
291   for (int32_t signo = GetFirstSignalNumber();
292        signo != LLDB_INVALID_SIGNAL_NUMBER;
293        signo = GetNextSignalNumber(signo)) {
294 
295     bool signal_suppress = false;
296     bool signal_stop = false;
297     bool signal_notify = false;
298     GetSignalInfo(signo, signal_suppress, signal_stop, signal_notify);
299 
300     // If any of filtering conditions are not met, we move on to the next
301     // signal.
302     if (should_suppress.hasValue() &&
303         signal_suppress != should_suppress.getValue())
304       continue;
305 
306     if (should_stop.hasValue() && signal_stop != should_stop.getValue())
307       continue;
308 
309     if (should_notify.hasValue() && signal_notify != should_notify.getValue())
310       continue;
311 
312     result.push_back(signo);
313   }
314 
315   return result;
316 }
317