llvm-project/lldb/source/Target/UnixSignals.cpp
David Spickett 0107513fe7 [lldb] Implement CrashReason using UnixSignals
By adding signal codes to UnixSignals and adding a new function
where you can get a string with optional address and bounds.

Added signal codes to the Linux, FreeBSD and NetBSD signal sets.
I've checked the numbers against the relevant sources.

Each signal code has a code number, description and printing options.
By default you just get the descripton, you can opt into adding either
a fault address or bounds information.

Bounds signals we'll use the description, unless we have the bounds
values in which case we say whether it is an upper or lower bound
issue.

GetCrashReasonString remains in CrashReason because we need it to
be compiled only for platforms with siginfo_t. Ideally it would
move into NativeProcessProtocol, but that is also used
by NativeRegisterContextWindows, where there would be no siginfo_t.

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D146044
2023-03-20 11:39:32 +00:00

408 lines
14 KiB
C++

//===-- UnixSignals.cpp ---------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Target/UnixSignals.h"
#include "Plugins/Process/Utility/FreeBSDSignals.h"
#include "Plugins/Process/Utility/LinuxSignals.h"
#include "Plugins/Process/Utility/NetBSDSignals.h"
#include "lldb/Host/HostInfo.h"
#include "lldb/Utility/ArchSpec.h"
#include <optional>
#include <sstream>
using namespace lldb_private;
using namespace llvm;
UnixSignals::Signal::Signal(const char *name, bool default_suppress,
bool default_stop, bool default_notify,
const char *description, const char *alias)
: m_name(name), m_alias(alias), m_description(),
m_suppress(default_suppress), m_stop(default_stop),
m_notify(default_notify),
m_default_suppress(default_suppress), m_default_stop(default_stop),
m_default_notify(default_notify) {
if (description)
m_description.assign(description);
}
lldb::UnixSignalsSP UnixSignals::Create(const ArchSpec &arch) {
const auto &triple = arch.GetTriple();
switch (triple.getOS()) {
case llvm::Triple::Linux:
return std::make_shared<LinuxSignals>();
case llvm::Triple::FreeBSD:
case llvm::Triple::OpenBSD:
return std::make_shared<FreeBSDSignals>();
case llvm::Triple::NetBSD:
return std::make_shared<NetBSDSignals>();
default:
return std::make_shared<UnixSignals>();
}
}
lldb::UnixSignalsSP UnixSignals::CreateForHost() {
static lldb::UnixSignalsSP s_unix_signals_sp =
Create(HostInfo::GetArchitecture());
return s_unix_signals_sp;
}
// UnixSignals constructor
UnixSignals::UnixSignals() { Reset(); }
UnixSignals::UnixSignals(const UnixSignals &rhs) : m_signals(rhs.m_signals) {}
UnixSignals::~UnixSignals() = default;
void UnixSignals::Reset() {
// This builds one standard set of Unix Signals. If yours aren't quite in
// this order, you can either subclass this class, and use Add & Remove to
// change them or you can subclass and build them afresh in your constructor.
//
// Note: the signals below are the Darwin signals. Do not change these!
m_signals.clear();
// clang-format off
// SIGNO NAME SUPPRESS STOP NOTIFY DESCRIPTION
// ====== ============== ======== ====== ====== ===================================================
AddSignal(1, "SIGHUP", false, true, true, "hangup");
AddSignal(2, "SIGINT", true, true, true, "interrupt");
AddSignal(3, "SIGQUIT", false, true, true, "quit");
AddSignal(4, "SIGILL", false, true, true, "illegal instruction");
AddSignal(5, "SIGTRAP", true, true, true, "trace trap (not reset when caught)");
AddSignal(6, "SIGABRT", false, true, true, "abort()");
AddSignal(7, "SIGEMT", false, true, true, "pollable event");
AddSignal(8, "SIGFPE", false, true, true, "floating point exception");
AddSignal(9, "SIGKILL", false, true, true, "kill");
AddSignal(10, "SIGBUS", false, true, true, "bus error");
AddSignal(11, "SIGSEGV", false, true, true, "segmentation violation");
AddSignal(12, "SIGSYS", false, true, true, "bad argument to system call");
AddSignal(13, "SIGPIPE", false, false, false, "write on a pipe with no one to read it");
AddSignal(14, "SIGALRM", false, false, false, "alarm clock");
AddSignal(15, "SIGTERM", false, true, true, "software termination signal from kill");
AddSignal(16, "SIGURG", false, false, false, "urgent condition on IO channel");
AddSignal(17, "SIGSTOP", true, true, true, "sendable stop signal not from tty");
AddSignal(18, "SIGTSTP", false, true, true, "stop signal from tty");
AddSignal(19, "SIGCONT", false, false, true, "continue a stopped process");
AddSignal(20, "SIGCHLD", false, false, false, "to parent on child stop or exit");
AddSignal(21, "SIGTTIN", false, true, true, "to readers process group upon background tty read");
AddSignal(22, "SIGTTOU", false, true, true, "to readers process group upon background tty write");
AddSignal(23, "SIGIO", false, false, false, "input/output possible signal");
AddSignal(24, "SIGXCPU", false, true, true, "exceeded CPU time limit");
AddSignal(25, "SIGXFSZ", false, true, true, "exceeded file size limit");
AddSignal(26, "SIGVTALRM", false, false, false, "virtual time alarm");
AddSignal(27, "SIGPROF", false, false, false, "profiling time alarm");
AddSignal(28, "SIGWINCH", false, false, false, "window size changes");
AddSignal(29, "SIGINFO", false, true, true, "information request");
AddSignal(30, "SIGUSR1", false, true, true, "user defined signal 1");
AddSignal(31, "SIGUSR2", false, true, true, "user defined signal 2");
// clang-format on
}
void UnixSignals::AddSignal(int signo, const char *name, bool default_suppress,
bool default_stop, bool default_notify,
const char *description, const char *alias) {
Signal new_signal(name, default_suppress, default_stop, default_notify,
description, alias);
m_signals.insert(std::make_pair(signo, new_signal));
++m_version;
}
void UnixSignals::AddSignalCode(int signo, int code, const char *description,
SignalCodePrintOption print_option) {
collection::iterator signal = m_signals.find(signo);
assert(signal != m_signals.end() &&
"Tried to add code to signal that does not exist.");
signal->second.m_codes.insert(
std::pair{code, SignalCode{ConstString(description), print_option}});
++m_version;
}
void UnixSignals::RemoveSignal(int signo) {
collection::iterator pos = m_signals.find(signo);
if (pos != m_signals.end())
m_signals.erase(pos);
++m_version;
}
const char *UnixSignals::GetSignalAsCString(int signo) const {
collection::const_iterator pos = m_signals.find(signo);
if (pos == m_signals.end())
return nullptr;
else
return pos->second.m_name.GetCString();
}
std::string
UnixSignals::GetSignalDescription(int32_t signo, std::optional<int32_t> code,
std::optional<lldb::addr_t> addr,
std::optional<lldb::addr_t> lower,
std::optional<lldb::addr_t> upper) const {
std::string str;
collection::const_iterator pos = m_signals.find(signo);
if (pos != m_signals.end()) {
str = pos->second.m_name.GetCString();
if (code) {
std::map<int, SignalCode>::const_iterator cpos =
pos->second.m_codes.find(*code);
if (cpos != pos->second.m_codes.end()) {
const SignalCode &sc = cpos->second;
str += ": ";
if (sc.m_print_option != SignalCodePrintOption::Bounds)
str += sc.m_description.GetCString();
std::stringstream strm;
switch (sc.m_print_option) {
case SignalCodePrintOption::None:
break;
case SignalCodePrintOption::Address:
if (addr)
strm << " (fault address: 0x" << std::hex << *addr << ")";
break;
case SignalCodePrintOption::Bounds:
if (lower && upper && addr) {
if ((unsigned long)(*addr) < *lower)
strm << "lower bound violation ";
else
strm << "upper bound violation ";
strm << "(fault address: 0x" << std::hex << *addr;
strm << ", lower bound: 0x" << std::hex << *lower;
strm << ", upper bound: 0x" << std::hex << *upper;
strm << ")";
} else
strm << sc.m_description.GetCString();
break;
}
str += strm.str();
}
}
}
return str;
}
bool UnixSignals::SignalIsValid(int32_t signo) const {
return m_signals.find(signo) != m_signals.end();
}
ConstString UnixSignals::GetShortName(ConstString name) const {
if (name)
return ConstString(name.GetStringRef().substr(3)); // Remove "SIG" from name
return name;
}
int32_t UnixSignals::GetSignalNumberFromName(const char *name) const {
ConstString const_name(name);
collection::const_iterator pos, end = m_signals.end();
for (pos = m_signals.begin(); pos != end; pos++) {
if ((const_name == pos->second.m_name) ||
(const_name == pos->second.m_alias) ||
(const_name == GetShortName(pos->second.m_name)) ||
(const_name == GetShortName(pos->second.m_alias)))
return pos->first;
}
int32_t signo;
if (llvm::to_integer(name, signo))
return signo;
return LLDB_INVALID_SIGNAL_NUMBER;
}
int32_t UnixSignals::GetFirstSignalNumber() const {
if (m_signals.empty())
return LLDB_INVALID_SIGNAL_NUMBER;
return (*m_signals.begin()).first;
}
int32_t UnixSignals::GetNextSignalNumber(int32_t current_signal) const {
collection::const_iterator pos = m_signals.find(current_signal);
collection::const_iterator end = m_signals.end();
if (pos == end)
return LLDB_INVALID_SIGNAL_NUMBER;
else {
pos++;
if (pos == end)
return LLDB_INVALID_SIGNAL_NUMBER;
else
return pos->first;
}
}
const char *UnixSignals::GetSignalInfo(int32_t signo, bool &should_suppress,
bool &should_stop,
bool &should_notify) const {
collection::const_iterator pos = m_signals.find(signo);
if (pos == m_signals.end())
return nullptr;
else {
const Signal &signal = pos->second;
should_suppress = signal.m_suppress;
should_stop = signal.m_stop;
should_notify = signal.m_notify;
return signal.m_name.AsCString("");
}
}
bool UnixSignals::GetShouldSuppress(int signo) const {
collection::const_iterator pos = m_signals.find(signo);
if (pos != m_signals.end())
return pos->second.m_suppress;
return false;
}
bool UnixSignals::SetShouldSuppress(int signo, bool value) {
collection::iterator pos = m_signals.find(signo);
if (pos != m_signals.end()) {
pos->second.m_suppress = value;
++m_version;
return true;
}
return false;
}
bool UnixSignals::SetShouldSuppress(const char *signal_name, bool value) {
const int32_t signo = GetSignalNumberFromName(signal_name);
if (signo != LLDB_INVALID_SIGNAL_NUMBER)
return SetShouldSuppress(signo, value);
return false;
}
bool UnixSignals::GetShouldStop(int signo) const {
collection::const_iterator pos = m_signals.find(signo);
if (pos != m_signals.end())
return pos->second.m_stop;
return false;
}
bool UnixSignals::SetShouldStop(int signo, bool value) {
collection::iterator pos = m_signals.find(signo);
if (pos != m_signals.end()) {
pos->second.m_stop = value;
++m_version;
return true;
}
return false;
}
bool UnixSignals::SetShouldStop(const char *signal_name, bool value) {
const int32_t signo = GetSignalNumberFromName(signal_name);
if (signo != LLDB_INVALID_SIGNAL_NUMBER)
return SetShouldStop(signo, value);
return false;
}
bool UnixSignals::GetShouldNotify(int signo) const {
collection::const_iterator pos = m_signals.find(signo);
if (pos != m_signals.end())
return pos->second.m_notify;
return false;
}
bool UnixSignals::SetShouldNotify(int signo, bool value) {
collection::iterator pos = m_signals.find(signo);
if (pos != m_signals.end()) {
pos->second.m_notify = value;
++m_version;
return true;
}
return false;
}
bool UnixSignals::SetShouldNotify(const char *signal_name, bool value) {
const int32_t signo = GetSignalNumberFromName(signal_name);
if (signo != LLDB_INVALID_SIGNAL_NUMBER)
return SetShouldNotify(signo, value);
return false;
}
int32_t UnixSignals::GetNumSignals() const { return m_signals.size(); }
int32_t UnixSignals::GetSignalAtIndex(int32_t index) const {
if (index < 0 || m_signals.size() <= static_cast<size_t>(index))
return LLDB_INVALID_SIGNAL_NUMBER;
auto it = m_signals.begin();
std::advance(it, index);
return it->first;
}
uint64_t UnixSignals::GetVersion() const { return m_version; }
std::vector<int32_t>
UnixSignals::GetFilteredSignals(std::optional<bool> should_suppress,
std::optional<bool> should_stop,
std::optional<bool> should_notify) {
std::vector<int32_t> result;
for (int32_t signo = GetFirstSignalNumber();
signo != LLDB_INVALID_SIGNAL_NUMBER;
signo = GetNextSignalNumber(signo)) {
bool signal_suppress = false;
bool signal_stop = false;
bool signal_notify = false;
GetSignalInfo(signo, signal_suppress, signal_stop, signal_notify);
// If any of filtering conditions are not met, we move on to the next
// signal.
if (should_suppress && signal_suppress != *should_suppress)
continue;
if (should_stop && signal_stop != *should_stop)
continue;
if (should_notify && signal_notify != *should_notify)
continue;
result.push_back(signo);
}
return result;
}
void UnixSignals::IncrementSignalHitCount(int signo) {
collection::iterator pos = m_signals.find(signo);
if (pos != m_signals.end())
pos->second.m_hit_count += 1;
}
json::Value UnixSignals::GetHitCountStatistics() const {
json::Array json_signals;
for (const auto &pair: m_signals) {
if (pair.second.m_hit_count > 0)
json_signals.emplace_back(json::Object{
{ pair.second.m_name.GetCString(), pair.second.m_hit_count }
});
}
return std::move(json_signals);
}
void UnixSignals::Signal::Reset(bool reset_stop, bool reset_notify,
bool reset_suppress) {
if (reset_stop)
m_stop = m_default_stop;
if (reset_notify)
m_notify = m_default_notify;
if (reset_suppress)
m_suppress = m_default_suppress;
}
bool UnixSignals::ResetSignal(int32_t signo, bool reset_stop,
bool reset_notify, bool reset_suppress) {
auto elem = m_signals.find(signo);
if (elem == m_signals.end())
return false;
(*elem).second.Reset(reset_stop, reset_notify, reset_suppress);
return true;
}