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