gem5  v22.0.0.2
init_signals.cc
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1 /*
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40  */
41 
42 #include "sim/init_signals.hh"
43 
44 #include <sys/types.h>
45 #include <unistd.h>
46 
47 #include <csignal>
48 #include <iostream>
49 #include <string>
50 
51 #if defined(__FreeBSD__)
52 #include <sys/param.h>
53 
54 #endif
55 
56 #include "base/atomicio.hh"
57 #include "base/cprintf.hh"
58 #include "base/logging.hh"
59 #include "sim/async.hh"
60 #include "sim/backtrace.hh"
61 #include "sim/eventq.hh"
62 
63 namespace gem5
64 {
65 
66 // Use an separate stack for fatal signal handlers
67 
68 static bool
70 {
71  const auto stack_size = 2 * SIGSTKSZ;
72  static uint8_t *fatal_sig_stack = new uint8_t[stack_size];
73  stack_t stack;
74 #if defined(__FreeBSD__) && (__FreeBSD_version < 1100097)
75  stack.ss_sp = (char *)fatal_sig_stack;
76 #else
77  stack.ss_sp = fatal_sig_stack;
78 #endif
79  stack.ss_size = stack_size;
80  stack.ss_flags = 0;
81 
82  return sigaltstack(&stack, NULL) == 0;
83 }
84 
85 static void
86 installSignalHandler(int signal, void (*handler)(int sigtype),
87  int flags = SA_RESTART)
88 {
89  struct sigaction sa;
90 
91  memset(&sa, 0, sizeof(sa));
92  sigemptyset(&sa.sa_mask);
93  sa.sa_handler = handler;
94  sa.sa_flags = flags;
95 
96  if (sigaction(signal, &sa, NULL) == -1)
97  panic("Failed to setup handler for signal %i\n", signal);
98 }
99 
100 static void
102 {
103  // The signal handler should have been reset and unmasked (it was
104  // registered with SA_RESETHAND | SA_NODEFER), just raise the
105  // signal again to invoke the default handler.
106  pthread_kill(pthread_self(), signo);
107 
108  // Something is really wrong if the process is alive at this
109  // point, manually try to exit it.
110  STATIC_ERR("Failed to execute default signal handler!\n");
111  _exit(127);
112 }
113 
115 void
116 dumpStatsHandler(int sigtype)
117 {
118  async_event = true;
119  async_statdump = true;
120  /* Wake up some event queue to handle event */
121  getEventQueue(0)->wakeup();
122 }
123 
124 void
126 {
127  async_event = true;
128  async_statdump = true;
129  async_statreset = true;
130  /* Wake up some event queue to handle event */
131  getEventQueue(0)->wakeup();
132 }
133 
135 void
136 exitNowHandler(int sigtype)
137 {
138  async_event = true;
139  async_exit = true;
140  /* Wake up some event queue to handle event */
141  getEventQueue(0)->wakeup();
142 }
143 
145 void
146 abortHandler(int sigtype)
147 {
148  const EventQueue *const eq(curEventQueue());
149  if (eq) {
150  ccprintf(std::cerr, "Program aborted at tick %llu\n",
151  eq->getCurTick());
152  } else {
153  STATIC_ERR("Program aborted\n\n");
154  }
155 
156  print_backtrace();
157  raiseFatalSignal(sigtype);
158 }
159 
161 static void
162 segvHandler(int sigtype)
163 {
164  STATIC_ERR("gem5 has encountered a segmentation fault!\n\n");
165 
166  print_backtrace();
167  raiseFatalSignal(SIGSEGV);
168 }
169 
170 // Handle SIGIO
171 static void
172 ioHandler(int sigtype)
173 {
174  async_event = true;
175  async_io = true;
176  /* Wake up some event queue to handle event */
177  getEventQueue(0)->wakeup();
178 }
179 
180 /*
181  * M5 can do several special things when various signals are sent.
182  * None are mandatory.
183  */
184 void
186 {
187  // Floating point exceptions may happen on misspeculated paths, so
188  // ignore them
189  signal(SIGFPE, SIG_IGN);
190 
191  // Dump intermediate stats
193 
194  // Dump intermediate stats and reset them
196 
197  // Exit cleanly on Interrupt (Ctrl-C)
199 
200  // Print the current cycle number and a backtrace on abort. Make
201  // sure the signal is unmasked and the handler reset when a signal
202  // is delivered to be able to invoke the default handler.
203  installSignalHandler(SIGABRT, abortHandler, SA_RESETHAND | SA_NODEFER);
204 
205  // Setup a SIGSEGV handler with a private stack
206  if (setupAltStack()) {
208  SA_RESETHAND | SA_NODEFER | SA_ONSTACK);
209  } else {
210  warn("Failed to setup stack for SIGSEGV handler, "
211  "using default signal handler.\n");
212  }
213 
214  // Install a SIGIO handler to handle asynchronous file IO. See the
215  // PollQueue class.
217 }
218 
219 } // namespace gem5
gem5::abortHandler
void abortHandler(int sigtype)
Abort signal handler.
Definition: init_signals.cc:146
warn
#define warn(...)
Definition: logging.hh:246
gem5::dumprstStatsHandler
void dumprstStatsHandler(int sigtype)
Definition: init_signals.cc:125
atomicio.hh
gem5::dumpStatsHandler
void dumpStatsHandler(int sigtype)
Stats signal handler.
Definition: init_signals.cc:116
gem5::async_exit
volatile bool async_exit
Async request to exit simulator.
Definition: async.cc:35
gem5::getEventQueue
EventQueue * getEventQueue(uint32_t index)
Function for returning eventq queue for the provided index.
Definition: eventq.cc:62
gem5::segvHandler
static void segvHandler(int sigtype)
Segmentation fault signal handler.
Definition: init_signals.cc:162
gem5::async_statreset
volatile bool async_statreset
Async request to reset stats.
Definition: async.cc:34
gem5::initSignals
void initSignals()
Definition: init_signals.cc:185
gem5::raiseFatalSignal
static void raiseFatalSignal(int signo)
Definition: init_signals.cc:101
gem5::EventQueue::wakeup
virtual void wakeup(Tick when=(Tick) -1)
Function to signal that the event loop should be woken up because an event has been scheduled by an a...
Definition: eventq.hh:930
gem5::exitNowHandler
void exitNowHandler(int sigtype)
Exit signal handler.
Definition: init_signals.cc:136
gem5::installSignalHandler
static void installSignalHandler(int signal, void(*handler)(int sigtype), int flags=SA_RESTART)
Definition: init_signals.cc:86
gem5::ccprintf
void ccprintf(cp::Print &print)
Definition: cprintf.hh:130
gem5::async_statdump
volatile bool async_statdump
Async request to dump stats.
Definition: async.cc:33
STATIC_ERR
#define STATIC_ERR(m)
Statically allocate a string and write it to STDERR.
Definition: atomicio.hh:67
gem5::X86ISA::stack
Bitfield< 17, 16 > stack
Definition: misc.hh:587
gem5::EventQueue
Queue of events sorted in time order.
Definition: eventq.hh:622
cprintf.hh
flags
uint8_t flags
Definition: helpers.cc:66
gem5::async_io
volatile bool async_io
Async I/O request (SIGIO).
Definition: async.cc:36
async.hh
gem5::curEventQueue
EventQueue * curEventQueue()
Definition: eventq.hh:88
gem5::PowerISA::eq
Bitfield< 29 > eq
Definition: misc.hh:53
gem5::setupAltStack
static bool setupAltStack()
Definition: init_signals.cc:69
logging.hh
init_signals.hh
gem5::ioHandler
static void ioHandler(int sigtype)
Definition: init_signals.cc:172
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: gpu_translation_state.hh:37
gem5::print_backtrace
void print_backtrace()
Print a gem5 post-mortem report.
Definition: backtrace_glibc.cc:54
backtrace.hh
gem5::async_event
volatile bool async_event
Some asynchronous event has happened.
Definition: async.cc:32
gem5::ArmISA::sa
Bitfield< 3 > sa
Definition: misc_types.hh:392
panic
#define panic(...)
This implements a cprintf based panic() function.
Definition: logging.hh:178
eventq.hh

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