lldb/source/Target/UnixSignals.cpp

   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
  18 using namespace lldb_private;
  19 using namespace llvm;
  20
  21 UnixSignals::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
  29 lldb::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
  44 lldb::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
  51 UnixSignals::UnixSignals() { Reset(); }
  52
  53 UnixSignals::UnixSignals(const UnixSignals &rhs) : m_signals(rhs.m_signals) {}
  54
  55 UnixSignals::~UnixSignals() = default;
  56
  57 void 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
 103 void 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
 113 void 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
 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 llvm::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
 138 std::string
 139 UnixSignals::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
 190 bool UnixSignals::SignalIsValid(int32_t signo) const {
 191   return m_signals.find(signo) != m_signals.end();
 192 }
 193
 194 llvm::StringRef UnixSignals::GetShortName(llvm::StringRef name) const {
 195   return name.substr(3); // Remove "SIG" from name
 196 }
 197
 198 int32_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
 215 int32_t UnixSignals::GetFirstSignalNumber() const {
 216   if (m_signals.empty())
 217     return LLDB_INVALID_SIGNAL_NUMBER;
 218
 219   return (*m_signals.begin()).first;
 220 }
 221
 222 int32_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
 236 bool 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
 249 bool 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
 256 bool 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
 266 bool 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
 273 bool 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
 280 bool 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
 290 bool 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
 297 bool 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
 304 bool 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
 314 bool 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
 321 int32_t UnixSignals::GetNumSignals() const { return m_signals.size(); }
 322
 323 int32_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
 331 uint64_t UnixSignals::GetVersion() const { return m_version; }
 332
 333 std::vector<int32_t>
 334 UnixSignals::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
 364 void 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
 370 json::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
 380 void 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
 390 bool 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