/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 *

 */

# include "incls/_precompiled.incl"

# include "incls/_vmError_linux.cpp.incl"

#include <sys/types.h>

#include <sys/wait.h>

#include <sys/syscall.h>

#include <unistd.h>

#include <signal.h>

void VMError::show_message_box(char *buf, int buflen) {

  bool yes;

  do {

    error_string(buf, buflen);

    int len = (int)strlen(buf);

    char *p = &buf[len];

    jio_snprintf(p, buflen - len,

               "\n\n"

               "Do you want to debug the problem?\n\n"

               "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT "\n"

               "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"

               "Otherwise, press RETURN to abort...",

               os::current_process_id(), os::current_process_id(),

               os::current_thread_id());

    yes = os::message_box("Unexpected Error", buf);

    if (yes) {

      // yes, user asked VM to launch debugger

      jio_snprintf(buf, buflen, "gdb /proc/%d/exe %d",

                   os::current_process_id(), os::current_process_id());

      os::fork_and_exec(buf);

      yes = false;

    }

  } while (yes);

}

// Space for our "saved" signal flags and handlers

static int resettedSigflags[2];

static address resettedSighandler[2];

static void save_signal(int idx, int sig)

{

  struct sigaction sa;

  sigaction(sig, NULL, &sa);

  resettedSigflags[idx]   = sa.sa_flags;

  resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO)

                              ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)

                              : CAST_FROM_FN_PTR(address, sa.sa_handler);

}

int VMError::get_resetted_sigflags(int sig) {

  if(SIGSEGV == sig) {

    return resettedSigflags[0];

  } else if(SIGBUS == sig) {

    return resettedSigflags[1];

  }

  return -1;

}

address VMError::get_resetted_sighandler(int sig) {

  if(SIGSEGV == sig) {

    return resettedSighandler[0];

  } else if(SIGBUS == sig) {

    return resettedSighandler[1];

  }

  return NULL;

}

static void crash_handler(int sig, siginfo_t* info, void* ucVoid) {

  // unmask current signal

  sigset_t newset;

  sigemptyset(&newset);

  sigaddset(&newset, sig);

  sigprocmask(SIG_UNBLOCK, &newset, NULL);

  VMError err(NULL, sig, NULL, info, ucVoid);

  err.report_and_die();

}

void VMError::reset_signal_handlers() {

  // Save sigflags for resetted signals

  save_signal(0, SIGSEGV);

  save_signal(1, SIGBUS);

  os::signal(SIGSEGV, CAST_FROM_FN_PTR(void *, crash_handler));

  os::signal(SIGBUS, CAST_FROM_FN_PTR(void *, crash_handler));

}