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/Utility/ArchSpec.h"
16 #include <optional>
17 
18 using namespace lldb_private;
19 using namespace llvm;
20 
21 UnixSignals::Signal::Signal(const char *name, bool default_suppress,
22                             bool default_stop, bool default_notify,
23                             const char *description, const char *alias)
24     : m_name(name), m_alias(alias), m_description(),
25       m_suppress(default_suppress), m_stop(default_stop),
26       m_notify(default_notify),
27       m_default_suppress(default_suppress), m_default_stop(default_stop),
28       m_default_notify(default_notify) {
29   if (description)
30     m_description.assign(description);
31 }
32 
33 lldb::UnixSignalsSP UnixSignals::Create(const ArchSpec &arch) {
34   const auto &triple = arch.GetTriple();
35   switch (triple.getOS()) {
36   case llvm::Triple::Linux: {
37     switch (triple.getArch()) {
38     case llvm::Triple::mips:
39     case llvm::Triple::mipsel:
40     case llvm::Triple::mips64:
41     case llvm::Triple::mips64el:
42       return std::make_shared<MipsLinuxSignals>();
43     default:
44       return std::make_shared<LinuxSignals>();
45     }
46   }
47   case llvm::Triple::FreeBSD:
48   case llvm::Triple::OpenBSD:
49     return std::make_shared<FreeBSDSignals>();
50   case llvm::Triple::NetBSD:
51     return std::make_shared<NetBSDSignals>();
52   default:
53     return std::make_shared<UnixSignals>();
54   }
55 }
56 
57 lldb::UnixSignalsSP UnixSignals::CreateForHost() {
58   static lldb::UnixSignalsSP s_unix_signals_sp =
59       Create(HostInfo::GetArchitecture());
60   return s_unix_signals_sp;
61 }
62 
63 // UnixSignals constructor
64 UnixSignals::UnixSignals() { Reset(); }
65 
66 UnixSignals::UnixSignals(const UnixSignals &rhs) : m_signals(rhs.m_signals) {}
67 
68 UnixSignals::~UnixSignals() = default;
69 
70 void UnixSignals::Reset() {
71   // This builds one standard set of Unix Signals. If yours aren't quite in
72   // this order, you can either subclass this class, and use Add & Remove to
73   // change them or you can subclass and build them afresh in your constructor.
74   //
75   // Note: the signals below are the Darwin signals. Do not change these!
76 
77   m_signals.clear();
78 
79   // clang-format off
80   //        SIGNO   NAME            SUPPRESS  STOP    NOTIFY  DESCRIPTION
81   //        ======  ==============  ========  ======  ======  ===================================================
82   AddSignal(1,      "SIGHUP",       false,    true,   true,   "hangup");
83   AddSignal(2,      "SIGINT",       true,     true,   true,   "interrupt");
84   AddSignal(3,      "SIGQUIT",      false,    true,   true,   "quit");
85   AddSignal(4,      "SIGILL",       false,    true,   true,   "illegal instruction");
86   AddSignal(5,      "SIGTRAP",      true,     true,   true,   "trace trap (not reset when caught)");
87   AddSignal(6,      "SIGABRT",      false,    true,   true,   "abort()");
88   AddSignal(7,      "SIGEMT",       false,    true,   true,   "pollable event");
89   AddSignal(8,      "SIGFPE",       false,    true,   true,   "floating point exception");
90   AddSignal(9,      "SIGKILL",      false,    true,   true,   "kill");
91   AddSignal(10,     "SIGBUS",       false,    true,   true,   "bus error");
92   AddSignal(11,     "SIGSEGV",      false,    true,   true,   "segmentation violation");
93   AddSignal(12,     "SIGSYS",       false,    true,   true,   "bad argument to system call");
94   AddSignal(13,     "SIGPIPE",      false,    false,  false,  "write on a pipe with no one to read it");
95   AddSignal(14,     "SIGALRM",      false,    false,  false,  "alarm clock");
96   AddSignal(15,     "SIGTERM",      false,    true,   true,   "software termination signal from kill");
97   AddSignal(16,     "SIGURG",       false,    false,  false,  "urgent condition on IO channel");
98   AddSignal(17,     "SIGSTOP",      true,     true,   true,   "sendable stop signal not from tty");
99   AddSignal(18,     "SIGTSTP",      false,    true,   true,   "stop signal from tty");
100   AddSignal(19,     "SIGCONT",      false,    false,  true,   "continue a stopped process");
101   AddSignal(20,     "SIGCHLD",      false,    false,  false,  "to parent on child stop or exit");
102   AddSignal(21,     "SIGTTIN",      false,    true,   true,   "to readers process group upon background tty read");
103   AddSignal(22,     "SIGTTOU",      false,    true,   true,   "to readers process group upon background tty write");
104   AddSignal(23,     "SIGIO",        false,    false,  false,  "input/output possible signal");
105   AddSignal(24,     "SIGXCPU",      false,    true,   true,   "exceeded CPU time limit");
106   AddSignal(25,     "SIGXFSZ",      false,    true,   true,   "exceeded file size limit");
107   AddSignal(26,     "SIGVTALRM",    false,    false,  false,  "virtual time alarm");
108   AddSignal(27,     "SIGPROF",      false,    false,  false,  "profiling time alarm");
109   AddSignal(28,     "SIGWINCH",     false,    false,  false,  "window size changes");
110   AddSignal(29,     "SIGINFO",      false,    true,   true,   "information request");
111   AddSignal(30,     "SIGUSR1",      false,    true,   true,   "user defined signal 1");
112   AddSignal(31,     "SIGUSR2",      false,    true,   true,   "user defined signal 2");
113   // clang-format on
114 }
115 
116 void UnixSignals::AddSignal(int signo, const char *name, bool default_suppress,
117                             bool default_stop, bool default_notify,
118                             const char *description, const char *alias) {
119   Signal new_signal(name, default_suppress, default_stop, default_notify,
120                     description, alias);
121   m_signals.insert(std::make_pair(signo, new_signal));
122   ++m_version;
123 }
124 
125 void UnixSignals::RemoveSignal(int signo) {
126   collection::iterator pos = m_signals.find(signo);
127   if (pos != m_signals.end())
128     m_signals.erase(pos);
129   ++m_version;
130 }
131 
132 const char *UnixSignals::GetSignalAsCString(int signo) const {
133   collection::const_iterator pos = m_signals.find(signo);
134   if (pos == m_signals.end())
135     return nullptr;
136   else
137     return pos->second.m_name.GetCString();
138 }
139 
140 bool UnixSignals::SignalIsValid(int32_t signo) const {
141   return m_signals.find(signo) != m_signals.end();
142 }
143 
144 ConstString UnixSignals::GetShortName(ConstString name) const {
145   if (name)
146     return ConstString(name.GetStringRef().substr(3)); // Remove "SIG" from name
147   return name;
148 }
149 
150 int32_t UnixSignals::GetSignalNumberFromName(const char *name) const {
151   ConstString const_name(name);
152 
153   collection::const_iterator pos, end = m_signals.end();
154   for (pos = m_signals.begin(); pos != end; pos++) {
155     if ((const_name == pos->second.m_name) ||
156         (const_name == pos->second.m_alias) ||
157         (const_name == GetShortName(pos->second.m_name)) ||
158         (const_name == GetShortName(pos->second.m_alias)))
159       return pos->first;
160   }
161 
162   int32_t signo;
163   if (llvm::to_integer(name, signo))
164     return signo;
165   return LLDB_INVALID_SIGNAL_NUMBER;
166 }
167 
168 int32_t UnixSignals::GetFirstSignalNumber() const {
169   if (m_signals.empty())
170     return LLDB_INVALID_SIGNAL_NUMBER;
171 
172   return (*m_signals.begin()).first;
173 }
174 
175 int32_t UnixSignals::GetNextSignalNumber(int32_t current_signal) const {
176   collection::const_iterator pos = m_signals.find(current_signal);
177   collection::const_iterator end = m_signals.end();
178   if (pos == end)
179     return LLDB_INVALID_SIGNAL_NUMBER;
180   else {
181     pos++;
182     if (pos == end)
183       return LLDB_INVALID_SIGNAL_NUMBER;
184     else
185       return pos->first;
186   }
187 }
188 
189 const char *UnixSignals::GetSignalInfo(int32_t signo, bool &should_suppress,
190                                        bool &should_stop,
191                                        bool &should_notify) const {
192   collection::const_iterator pos = m_signals.find(signo);
193   if (pos == m_signals.end())
194     return nullptr;
195   else {
196     const Signal &signal = pos->second;
197     should_suppress = signal.m_suppress;
198     should_stop = signal.m_stop;
199     should_notify = signal.m_notify;
200     return signal.m_name.AsCString("");
201   }
202 }
203 
204 bool UnixSignals::GetShouldSuppress(int signo) const {
205   collection::const_iterator pos = m_signals.find(signo);
206   if (pos != m_signals.end())
207     return pos->second.m_suppress;
208   return false;
209 }
210 
211 bool UnixSignals::SetShouldSuppress(int signo, bool value) {
212   collection::iterator pos = m_signals.find(signo);
213   if (pos != m_signals.end()) {
214     pos->second.m_suppress = value;
215     ++m_version;
216     return true;
217   }
218   return false;
219 }
220 
221 bool UnixSignals::SetShouldSuppress(const char *signal_name, bool value) {
222   const int32_t signo = GetSignalNumberFromName(signal_name);
223   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
224     return SetShouldSuppress(signo, value);
225   return false;
226 }
227 
228 bool UnixSignals::GetShouldStop(int signo) const {
229   collection::const_iterator pos = m_signals.find(signo);
230   if (pos != m_signals.end())
231     return pos->second.m_stop;
232   return false;
233 }
234 
235 bool UnixSignals::SetShouldStop(int signo, bool value) {
236   collection::iterator pos = m_signals.find(signo);
237   if (pos != m_signals.end()) {
238     pos->second.m_stop = value;
239     ++m_version;
240     return true;
241   }
242   return false;
243 }
244 
245 bool UnixSignals::SetShouldStop(const char *signal_name, bool value) {
246   const int32_t signo = GetSignalNumberFromName(signal_name);
247   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
248     return SetShouldStop(signo, value);
249   return false;
250 }
251 
252 bool UnixSignals::GetShouldNotify(int signo) const {
253   collection::const_iterator pos = m_signals.find(signo);
254   if (pos != m_signals.end())
255     return pos->second.m_notify;
256   return false;
257 }
258 
259 bool UnixSignals::SetShouldNotify(int signo, bool value) {
260   collection::iterator pos = m_signals.find(signo);
261   if (pos != m_signals.end()) {
262     pos->second.m_notify = value;
263     ++m_version;
264     return true;
265   }
266   return false;
267 }
268 
269 bool UnixSignals::SetShouldNotify(const char *signal_name, bool value) {
270   const int32_t signo = GetSignalNumberFromName(signal_name);
271   if (signo != LLDB_INVALID_SIGNAL_NUMBER)
272     return SetShouldNotify(signo, value);
273   return false;
274 }
275 
276 int32_t UnixSignals::GetNumSignals() const { return m_signals.size(); }
277 
278 int32_t UnixSignals::GetSignalAtIndex(int32_t index) const {
279   if (index < 0 || m_signals.size() <= static_cast<size_t>(index))
280     return LLDB_INVALID_SIGNAL_NUMBER;
281   auto it = m_signals.begin();
282   std::advance(it, index);
283   return it->first;
284 }
285 
286 uint64_t UnixSignals::GetVersion() const { return m_version; }
287 
288 std::vector<int32_t>
289 UnixSignals::GetFilteredSignals(std::optional<bool> should_suppress,
290                                 std::optional<bool> should_stop,
291                                 std::optional<bool> should_notify) {
292   std::vector<int32_t> result;
293   for (int32_t signo = GetFirstSignalNumber();
294        signo != LLDB_INVALID_SIGNAL_NUMBER;
295        signo = GetNextSignalNumber(signo)) {
296 
297     bool signal_suppress = false;
298     bool signal_stop = false;
299     bool signal_notify = false;
300     GetSignalInfo(signo, signal_suppress, signal_stop, signal_notify);
301 
302     // If any of filtering conditions are not met, we move on to the next
303     // signal.
304     if (should_suppress && signal_suppress != *should_suppress)
305       continue;
306 
307     if (should_stop && signal_stop != *should_stop)
308       continue;
309 
310     if (should_notify && signal_notify != *should_notify)
311       continue;
312 
313     result.push_back(signo);
314   }
315 
316   return result;
317 }
318 
319 void UnixSignals::IncrementSignalHitCount(int signo) {
320   collection::iterator pos = m_signals.find(signo);
321   if (pos != m_signals.end())
322     pos->second.m_hit_count += 1;
323 }
324 
325 json::Value UnixSignals::GetHitCountStatistics() const {
326   json::Array json_signals;
327   for (const auto &pair: m_signals) {
328     if (pair.second.m_hit_count > 0)
329       json_signals.emplace_back(json::Object{
330         { pair.second.m_name.GetCString(), pair.second.m_hit_count }
331       });
332   }
333   return std::move(json_signals);
334 }
335 
336 void UnixSignals::Signal::Reset(bool reset_stop, bool reset_notify,
337                                 bool reset_suppress) {
338   if (reset_stop)
339     m_stop = m_default_stop;
340   if (reset_notify)
341     m_notify = m_default_notify;
342   if (reset_suppress)
343     m_suppress = m_default_suppress;
344 }
345 
346 bool UnixSignals::ResetSignal(int32_t signo, bool reset_stop,
347                                  bool reset_notify, bool reset_suppress) {
348     auto elem = m_signals.find(signo);
349     if (elem == m_signals.end())
350       return false;
351     (*elem).second.Reset(reset_stop, reset_notify, reset_suppress);
352     return true;
353 }
354 
355