1 /*

     2  * Copyright (c) 2003, 2013, 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 <unistd.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 -a %d'; then switch to thread tid " INTX_FORMAT ", k-tid " 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(),

    50                  os::current_thread_id(), thread_self());

    51 

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

    53 

    54     if (yes) {

    55       // yes, user asked VM to launch debugger

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

    57 

    58       os::fork_and_exec(buf);

    59       yes = false;

    60     }

    61   } while (yes);

    62 }

    63 

    64 // Handle all synchronous signals which may happen during signal handling,

    65 // not just SIGSEGV and SIGBUS.

    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   struct sigaction sa;

    75   sigaction(sig, NULL, &sa);

    76   resettedSigflags[idx]   = sa.sa_flags;

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

    78                               ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)

    79                               : CAST_FROM_FN_PTR(address, sa.sa_handler);

    80 }

    81 

    82 int VMError::get_resetted_sigflags(int sig) {

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

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

    85       return resettedSigflags[i];

    86     }

    87   }

    88   return -1;

    89 }

    90 

    91 address VMError::get_resetted_sighandler(int sig) {

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

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

    94       return resettedSighandler[i];

    95     }

    96   }

    97   return NULL;

    98 }

    99 

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

   101 

   102   // Unmask current signal.

   103   sigset_t newset;

   104   sigemptyset(&newset);

   105   sigaddset(&newset, sig);

   106   // and all other synchronous signals too.

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

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

   109   }

   110   sigthreadmask(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::Aix::ucontext_get_pc(uc) : NULL;

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

   116     os::Aix::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   sigset_t newset;

   125   sigemptyset(&newset);

   126 

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

   128     save_signal(i, SIGNALS[i]);

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

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

   131   }

   132 

   133   sigthreadmask(SIG_UNBLOCK, &newset, NULL);

   134 }