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/NetBSDSignals.h"
13#include "lldb/Host/HostInfo.h"
14#include "lldb/Utility/ArchSpec.h"
15#include <optional>
16#include <sstream>
17
18using namespace lldb_private;
19using namespace llvm;
20
21UnixSignals::Signal::Signal(llvm::StringRef name, bool default_suppress,
22                            bool default_stop, bool default_notify,
23                            llvm::StringRef description, llvm::StringRef alias)
24    : m_name(name), m_alias(alias), m_description(description),
25      m_suppress(default_suppress), m_stop(default_stop),
26      m_notify(default_notify), m_default_suppress(default_suppress),
27      m_default_stop(default_stop), m_default_notify(default_notify) {}
28
29lldb::UnixSignalsSP UnixSignals::Create(const ArchSpec &arch) {
30  const auto &triple = arch.GetTriple();
31  switch (triple.getOS()) {
32  case llvm::Triple::Linux:
33    return std::make_shared<LinuxSignals>();
34  case llvm::Triple::FreeBSD:
35  case llvm::Triple::OpenBSD:
36    return std::make_shared<FreeBSDSignals>();
37  case llvm::Triple::NetBSD:
38    return std::make_shared<NetBSDSignals>();
39  default:
40    return std::make_shared<UnixSignals>();
41  }
42}
43
44lldb::UnixSignalsSP UnixSignals::CreateForHost() {
45  static lldb::UnixSignalsSP s_unix_signals_sp =
46      Create(HostInfo::GetArchitecture());
47  return s_unix_signals_sp;
48}
49
50// UnixSignals constructor
51UnixSignals::UnixSignals() { Reset(); }
52
53UnixSignals::UnixSignals(const UnixSignals &rhs) : m_signals(rhs.m_signals) {}
54
55UnixSignals::~UnixSignals() = default;
56
57void UnixSignals::Reset() {
58  // This builds one standard set of Unix Signals. If yours aren't quite in
59  // this order, you can either subclass this class, and use Add & Remove to
60  // change them or you can subclass and build them afresh in your constructor.
61  //
62  // Note: the signals below are the Darwin signals. Do not change these!
63
64  m_signals.clear();
65
66  // clang-format off
67  //        SIGNO   NAME            SUPPRESS  STOP    NOTIFY  DESCRIPTION
68  //        ======  ==============  ========  ======  ======  ===================================================
69  AddSignal(1,      "SIGHUP",       false,    true,   true,   "hangup");
70  AddSignal(2,      "SIGINT",       true,     true,   true,   "interrupt");
71  AddSignal(3,      "SIGQUIT",      false,    true,   true,   "quit");
72  AddSignal(4,      "SIGILL",       false,    true,   true,   "illegal instruction");
73  AddSignal(5,      "SIGTRAP",      true,     true,   true,   "trace trap (not reset when caught)");
74  AddSignal(6,      "SIGABRT",      false,    true,   true,   "abort()");
75  AddSignal(7,      "SIGEMT",       false,    true,   true,   "pollable event");
76  AddSignal(8,      "SIGFPE",       false,    true,   true,   "floating point exception");
77  AddSignal(9,      "SIGKILL",      false,    true,   true,   "kill");
78  AddSignal(10,     "SIGBUS",       false,    true,   true,   "bus error");
79  AddSignal(11,     "SIGSEGV",      false,    true,   true,   "segmentation violation");
80  AddSignal(12,     "SIGSYS",       false,    true,   true,   "bad argument to system call");
81  AddSignal(13,     "SIGPIPE",      false,    false,  false,  "write on a pipe with no one to read it");
82  AddSignal(14,     "SIGALRM",      false,    false,  false,  "alarm clock");
83  AddSignal(15,     "SIGTERM",      false,    true,   true,   "software termination signal from kill");
84  AddSignal(16,     "SIGURG",       false,    false,  false,  "urgent condition on IO channel");
85  AddSignal(17,     "SIGSTOP",      true,     true,   true,   "sendable stop signal not from tty");
86  AddSignal(18,     "SIGTSTP",      false,    true,   true,   "stop signal from tty");
87  AddSignal(19,     "SIGCONT",      false,    false,  true,   "continue a stopped process");
88  AddSignal(20,     "SIGCHLD",      false,    false,  false,  "to parent on child stop or exit");
89  AddSignal(21,     "SIGTTIN",      false,    true,   true,   "to readers process group upon background tty read");
90  AddSignal(22,     "SIGTTOU",      false,    true,   true,   "to readers process group upon background tty write");
91  AddSignal(23,     "SIGIO",        false,    false,  false,  "input/output possible signal");
92  AddSignal(24,     "SIGXCPU",      false,    true,   true,   "exceeded CPU time limit");
93  AddSignal(25,     "SIGXFSZ",      false,    true,   true,   "exceeded file size limit");
94  AddSignal(26,     "SIGVTALRM",    false,    false,  false,  "virtual time alarm");
95  AddSignal(27,     "SIGPROF",      false,    false,  false,  "profiling time alarm");
96  AddSignal(28,     "SIGWINCH",     false,    false,  false,  "window size changes");
97  AddSignal(29,     "SIGINFO",      false,    true,   true,   "information request");
98  AddSignal(30,     "SIGUSR1",      false,    true,   true,   "user defined signal 1");
99  AddSignal(31,     "SIGUSR2",      false,    true,   true,   "user defined signal 2");
100  // clang-format on
101}
102
103void UnixSignals::AddSignal(int signo, llvm::StringRef name,
104                            bool default_suppress, bool default_stop,
105                            bool default_notify, llvm::StringRef description,
106                            llvm::StringRef alias) {
107  Signal new_signal(name, default_suppress, default_stop, default_notify,
108                    description, alias);
109  m_signals.insert(std::make_pair(signo, new_signal));
110  ++m_version;
111}
112
113void UnixSignals::AddSignalCode(int signo, int code,
114                                const llvm::StringLiteral description,
115                                SignalCodePrintOption print_option) {
116  collection::iterator signal = m_signals.find(signo);
117  assert(signal != m_signals.end() &&
118         "Tried to add code to signal that does not exist.");
119  signal->second.m_codes.insert(
120      std::pair{code, SignalCode{description, print_option}});
121  ++m_version;
122}
123
124void 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
131llvm::StringRef UnixSignals::GetSignalAsStringRef(int32_t signo) const {
132  const auto pos = m_signals.find(signo);
133  if (pos == m_signals.end())
134    return {};
135  return pos->second.m_name;
136}
137
138std::string
139UnixSignals::GetSignalDescription(int32_t signo, std::optional<int32_t> code,
140                                  std::optional<lldb::addr_t> addr,
141                                  std::optional<lldb::addr_t> lower,
142                                  std::optional<lldb::addr_t> upper) const {
143  std::string str;
144
145  collection::const_iterator pos = m_signals.find(signo);
146  if (pos != m_signals.end()) {
147    str = pos->second.m_name.str();
148
149    if (code) {
150      std::map<int32_t, SignalCode>::const_iterator cpos =
151          pos->second.m_codes.find(*code);
152      if (cpos != pos->second.m_codes.end()) {
153        const SignalCode &sc = cpos->second;
154        str += ": ";
155        if (sc.m_print_option != SignalCodePrintOption::Bounds)
156          str += sc.m_description.str();
157
158        std::stringstream strm;
159        switch (sc.m_print_option) {
160        case SignalCodePrintOption::None:
161          break;
162        case SignalCodePrintOption::Address:
163          if (addr)
164            strm << " (fault address: 0x" << std::hex << *addr << ")";
165          break;
166        case SignalCodePrintOption::Bounds:
167          if (lower && upper && addr) {
168            if ((unsigned long)(*addr) < *lower)
169              strm << "lower bound violation ";
170            else
171              strm << "upper bound violation ";
172
173            strm << "(fault address: 0x" << std::hex << *addr;
174            strm << ", lower bound: 0x" << std::hex << *lower;
175            strm << ", upper bound: 0x" << std::hex << *upper;
176            strm << ")";
177          } else
178            strm << sc.m_description.str();
179
180          break;
181        }
182        str += strm.str();
183      }
184    }
185  }
186
187  return str;
188}
189
190bool UnixSignals::SignalIsValid(int32_t signo) const {
191  return m_signals.find(signo) != m_signals.end();
192}
193
194llvm::StringRef UnixSignals::GetShortName(llvm::StringRef name) const {
195  return name.substr(3); // Remove "SIG" from name
196}
197
198int32_t UnixSignals::GetSignalNumberFromName(const char *name) const {
199  llvm::StringRef name_ref(name);
200
201  collection::const_iterator pos, end = m_signals.end();
202  for (pos = m_signals.begin(); pos != end; pos++) {
203    if ((name_ref == pos->second.m_name) || (name_ref == pos->second.m_alias) ||
204        (name_ref == GetShortName(pos->second.m_name)) ||
205        (name_ref == GetShortName(pos->second.m_alias)))
206      return pos->first;
207  }
208
209  int32_t signo;
210  if (llvm::to_integer(name, signo))
211    return signo;
212  return LLDB_INVALID_SIGNAL_NUMBER;
213}
214
215int32_t UnixSignals::GetFirstSignalNumber() const {
216  if (m_signals.empty())
217    return LLDB_INVALID_SIGNAL_NUMBER;
218
219  return (*m_signals.begin()).first;
220}
221
222int32_t UnixSignals::GetNextSignalNumber(int32_t current_signal) const {
223  collection::const_iterator pos = m_signals.find(current_signal);
224  collection::const_iterator end = m_signals.end();
225  if (pos == end)
226    return LLDB_INVALID_SIGNAL_NUMBER;
227  else {
228    pos++;
229    if (pos == end)
230      return LLDB_INVALID_SIGNAL_NUMBER;
231    else
232      return pos->first;
233  }
234}
235
236bool UnixSignals::GetSignalInfo(int32_t signo, bool &should_suppress,
237                                bool &should_stop, bool &should_notify) const {
238  const auto pos = m_signals.find(signo);
239  if (pos == m_signals.end())
240    return false;
241
242  const Signal &signal = pos->second;
243  should_suppress = signal.m_suppress;
244  should_stop = signal.m_stop;
245  should_notify = signal.m_notify;
246  return true;
247}
248
249bool UnixSignals::GetShouldSuppress(int signo) const {
250  collection::const_iterator pos = m_signals.find(signo);
251  if (pos != m_signals.end())
252    return pos->second.m_suppress;
253  return false;
254}
255
256bool UnixSignals::SetShouldSuppress(int signo, bool value) {
257  collection::iterator pos = m_signals.find(signo);
258  if (pos != m_signals.end()) {
259    pos->second.m_suppress = value;
260    ++m_version;
261    return true;
262  }
263  return false;
264}
265
266bool UnixSignals::SetShouldSuppress(const char *signal_name, bool value) {
267  const int32_t signo = GetSignalNumberFromName(signal_name);
268  if (signo != LLDB_INVALID_SIGNAL_NUMBER)
269    return SetShouldSuppress(signo, value);
270  return false;
271}
272
273bool UnixSignals::GetShouldStop(int signo) const {
274  collection::const_iterator pos = m_signals.find(signo);
275  if (pos != m_signals.end())
276    return pos->second.m_stop;
277  return false;
278}
279
280bool UnixSignals::SetShouldStop(int signo, bool value) {
281  collection::iterator pos = m_signals.find(signo);
282  if (pos != m_signals.end()) {
283    pos->second.m_stop = value;
284    ++m_version;
285    return true;
286  }
287  return false;
288}
289
290bool UnixSignals::SetShouldStop(const char *signal_name, bool value) {
291  const int32_t signo = GetSignalNumberFromName(signal_name);
292  if (signo != LLDB_INVALID_SIGNAL_NUMBER)
293    return SetShouldStop(signo, value);
294  return false;
295}
296
297bool UnixSignals::GetShouldNotify(int signo) const {
298  collection::const_iterator pos = m_signals.find(signo);
299  if (pos != m_signals.end())
300    return pos->second.m_notify;
301  return false;
302}
303
304bool UnixSignals::SetShouldNotify(int signo, bool value) {
305  collection::iterator pos = m_signals.find(signo);
306  if (pos != m_signals.end()) {
307    pos->second.m_notify = value;
308    ++m_version;
309    return true;
310  }
311  return false;
312}
313
314bool UnixSignals::SetShouldNotify(const char *signal_name, bool value) {
315  const int32_t signo = GetSignalNumberFromName(signal_name);
316  if (signo != LLDB_INVALID_SIGNAL_NUMBER)
317    return SetShouldNotify(signo, value);
318  return false;
319}
320
321int32_t UnixSignals::GetNumSignals() const { return m_signals.size(); }
322
323int32_t UnixSignals::GetSignalAtIndex(int32_t index) const {
324  if (index < 0 || m_signals.size() <= static_cast<size_t>(index))
325    return LLDB_INVALID_SIGNAL_NUMBER;
326  auto it = m_signals.begin();
327  std::advance(it, index);
328  return it->first;
329}
330
331uint64_t UnixSignals::GetVersion() const { return m_version; }
332
333std::vector<int32_t>
334UnixSignals::GetFilteredSignals(std::optional<bool> should_suppress,
335                                std::optional<bool> should_stop,
336                                std::optional<bool> should_notify) {
337  std::vector<int32_t> result;
338  for (int32_t signo = GetFirstSignalNumber();
339       signo != LLDB_INVALID_SIGNAL_NUMBER;
340       signo = GetNextSignalNumber(signo)) {
341
342    bool signal_suppress = false;
343    bool signal_stop = false;
344    bool signal_notify = false;
345    GetSignalInfo(signo, signal_suppress, signal_stop, signal_notify);
346
347    // If any of filtering conditions are not met, we move on to the next
348    // signal.
349    if (should_suppress && signal_suppress != *should_suppress)
350      continue;
351
352    if (should_stop && signal_stop != *should_stop)
353      continue;
354
355    if (should_notify && signal_notify != *should_notify)
356      continue;
357
358    result.push_back(signo);
359  }
360
361  return result;
362}
363
364void UnixSignals::IncrementSignalHitCount(int signo) {
365  collection::iterator pos = m_signals.find(signo);
366  if (pos != m_signals.end())
367    pos->second.m_hit_count += 1;
368}
369
370json::Value UnixSignals::GetHitCountStatistics() const {
371  json::Array json_signals;
372  for (const auto &pair : m_signals) {
373    if (pair.second.m_hit_count > 0)
374      json_signals.emplace_back(
375          json::Object{{pair.second.m_name, pair.second.m_hit_count}});
376  }
377  return std::move(json_signals);
378}
379
380void UnixSignals::Signal::Reset(bool reset_stop, bool reset_notify,
381                                bool reset_suppress) {
382  if (reset_stop)
383    m_stop = m_default_stop;
384  if (reset_notify)
385    m_notify = m_default_notify;
386  if (reset_suppress)
387    m_suppress = m_default_suppress;
388}
389
390bool UnixSignals::ResetSignal(int32_t signo, bool reset_stop,
391                                 bool reset_notify, bool reset_suppress) {
392    auto elem = m_signals.find(signo);
393    if (elem == m_signals.end())
394      return false;
395    (*elem).second.Reset(reset_stop, reset_notify, reset_suppress);
396    return true;
397}
398
399