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/*
* Copyright (c) 2012, 2015 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Copyright (c) 2000-2005 The Regents of The University of Michigan
* Copyright (c) 2008 The Hewlett-Packard Development Company
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Nathan Binkert
*/
#include "sim/init_signals.hh"
#include <sys/types.h>
#include <unistd.h>
#include <csignal>
#include <iostream>
#include <string>
#if defined(__FreeBSD__)
#include <sys/param.h>
#endif
#include "base/atomicio.hh"
#include "base/cprintf.hh"
#include "base/misc.hh"
#include "sim/async.hh"
#include "sim/backtrace.hh"
#include "sim/core.hh"
#include "sim/eventq.hh"
using namespace std;
// Use an separate stack for fatal signal handlers
static uint8_t fatalSigStack[2 * SIGSTKSZ];
static bool
setupAltStack()
{
stack_t stack;
#if defined(__FreeBSD__) && (__FreeBSD_version < 1100097)
stack.ss_sp = (char *)fatalSigStack;
#else
stack.ss_sp = fatalSigStack;
#endif
stack.ss_size = sizeof(fatalSigStack);
stack.ss_flags = 0;
return sigaltstack(&stack, NULL) == 0;
}
static void
installSignalHandler(int signal, void (*handler)(int sigtype),
int flags = SA_RESTART)
{
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_handler = handler;
sa.sa_flags = flags;
if (sigaction(signal, &sa, NULL) == -1)
panic("Failed to setup handler for signal %i\n", signal);
}
static void
raiseFatalSignal(int signo)
{
// The signal handler should have been reset and unmasked (it was
// registered with SA_RESETHAND | SA_NODEFER), just raise the
// signal again to invoke the default handler.
pthread_kill(pthread_self(), signo);
// Something is really wrong if the process is alive at this
// point, manually try to exit it.
STATIC_ERR("Failed to execute default signal handler!\n");
_exit(127);
}
/// Stats signal handler.
void
dumpStatsHandler(int sigtype)
{
async_event = true;
async_statdump = true;
/* Wake up some event queue to handle event */
getEventQueue(0)->wakeup();
}
void
dumprstStatsHandler(int sigtype)
{
async_event = true;
async_statdump = true;
async_statreset = true;
/* Wake up some event queue to handle event */
getEventQueue(0)->wakeup();
}
/// Exit signal handler.
void
exitNowHandler(int sigtype)
{
async_event = true;
async_exit = true;
/* Wake up some event queue to handle event */
getEventQueue(0)->wakeup();
}
/// Abort signal handler.
void
abortHandler(int sigtype)
{
const EventQueue *const eq(curEventQueue());
if (eq) {
ccprintf(cerr, "Program aborted at tick %llu\n", eq->getCurTick());
} else {
STATIC_ERR("Program aborted\n\n");
}
print_backtrace();
raiseFatalSignal(sigtype);
}
/// Segmentation fault signal handler.
static void
segvHandler(int sigtype)
{
STATIC_ERR("gem5 has encountered a segmentation fault!\n\n");
print_backtrace();
raiseFatalSignal(SIGSEGV);
}
// Handle SIGIO
static void
ioHandler(int sigtype)
{
async_event = true;
async_io = true;
/* Wake up some event queue to handle event */
getEventQueue(0)->wakeup();
}
/*
* M5 can do several special things when various signals are sent.
* None are mandatory.
*/
void
initSignals()
{
// Floating point exceptions may happen on misspeculated paths, so
// ignore them
signal(SIGFPE, SIG_IGN);
// Dump intermediate stats
installSignalHandler(SIGUSR1, dumpStatsHandler);
// Dump intermediate stats and reset them
installSignalHandler(SIGUSR2, dumprstStatsHandler);
// Exit cleanly on Interrupt (Ctrl-C)
installSignalHandler(SIGINT, exitNowHandler);
// Print the current cycle number and a backtrace on abort. Make
// sure the signal is unmasked and the handler reset when a signal
// is delivered to be able to invoke the default handler.
installSignalHandler(SIGABRT, abortHandler, SA_RESETHAND | SA_NODEFER);
// Setup a SIGSEGV handler with a private stack
if (setupAltStack()) {
installSignalHandler(SIGSEGV, segvHandler,
SA_RESETHAND | SA_NODEFER | SA_ONSTACK);
} else {
warn("Failed to setup stack for SIGSEGV handler, "
"using default signal handler.\n");
}
// Install a SIGIO handler to handle asynchronous file IO. See the
// PollQueue class.
installSignalHandler(SIGIO, ioHandler);
}