1 /*

     2  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #include "precompiled.hpp"

    26 #include "runtime/arguments.hpp"

    27 #include "runtime/os.hpp"

    28 #include "runtime/thread.hpp"

    29 #include "utilities/vmError.hpp"

    30 

    31 #include <sys/types.h>

    32 #include <sys/wait.h>

    33 #include <thread.h>

    34 #include <signal.h>

    35 

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

    37   bool yes;

    38   do {

    39     error_string(buf, buflen);

    40     int len = (int)strlen(buf);

    41     char *p = &buf[len];

    42 

    43     jio_snprintf(p, buflen - len,

    44                "\n\n"

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

    46                "To debug, run 'dbx - %d'; then switch to thread " INTX_FORMAT "\n"

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

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

    49                os::current_process_id(), os::current_thread_id());

    50 

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

    52 

    53     if (yes) {

    54       // yes, user asked VM to launch debugger

    55       jio_snprintf(buf, buflen, "dbx - %d", os::current_process_id());

    56 

    57       os::fork_and_exec(buf);

    58       yes = false;

    59     }

    60   } while (yes);

    61 }

    62 

    63 // handle all synchronous program error signals which may happen during error

    64 // reporting. They must be unblocked, caught, handled.

    65 

    66 static const int SIGNALS[] = { SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP }; // add more if needed

    67 static const int NUM_SIGNALS = sizeof(SIGNALS) / sizeof(int);

    68 

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

    70 static int resettedSigflags[NUM_SIGNALS];

    71 static address resettedSighandler[NUM_SIGNALS];

    72 

    73 static void save_signal(int idx, int sig)

    74 {

    75   struct sigaction sa;

    76   sigaction(sig, NULL, &sa);

    77   resettedSigflags[idx]   = sa.sa_flags;

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

    79                               ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)

    80                               : CAST_FROM_FN_PTR(address, sa.sa_handler);

    81 }

    82 

    83 int VMError::get_resetted_sigflags(int sig) {

    84   for (int i = 0; i < NUM_SIGNALS; i++) {

    85     if (SIGNALS[i] == sig) {

    86       return resettedSigflags[i];

    87     }

    88   }

    89   return -1;

    90 }

    91 

    92 address VMError::get_resetted_sighandler(int sig) {

    93   for (int i = 0; i < NUM_SIGNALS; i++) {

    94     if (SIGNALS[i] == sig) {

    95       return resettedSighandler[i];

    96     }

    97   }

    98   return NULL;

    99 }

   100 

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

   102   // unmask current signal

   103   sigset_t newset;

   104   sigemptyset(&newset);

   105   sigaddset(&newset, sig);

   106   // also unmask other synchronous signals

   107   for (int i = 0; i < NUM_SIGNALS; i++) {

   108     sigaddset(&newset, SIGNALS[i]);

   109   }

   110   thr_sigsetmask(SIG_UNBLOCK, &newset, NULL);

   111 

   112   // support safefetch faults in error handling

   113   ucontext_t* const uc = (ucontext_t*) ucVoid;

   114   address const pc = uc ? os::Solaris::ucontext_get_pc(uc) : NULL;

   115   if (uc && pc && StubRoutines::is_safefetch_fault(pc)) {

   116     os::Solaris::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));

   117     return;

   118   }

   119 

   120   VMError::report_and_die(NULL, sig, pc, info, ucVoid);

   121 }

   122 

   123 void VMError::reset_signal_handlers() {

   124   // install signal handlers for all synchronous program error signals

   125   sigset_t newset;

   126   sigemptyset(&newset);

   127 

   128   for (int i = 0; i < NUM_SIGNALS; i++) {

   129     save_signal(i, SIGNALS[i]);

   130     os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler));

   131     sigaddset(&newset, SIGNALS[i]);

   132   }

   133   thr_sigsetmask(SIG_UNBLOCK, &newset, NULL);

   134 }