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 <sys/syscall.h>

    34 #include <unistd.h>

    35 #include <signal.h>

    36 

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

    38   bool yes;

    39   do {

    40     error_string(buf, buflen);

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

    42     char *p = &buf[len];

    43 

    44     jio_snprintf(p, buflen - len,

    45                "\n\n"

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

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

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

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

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

    51                os::current_thread_id(), os::current_thread_id());

    52 

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

    54 

    55     if (yes) {

    56       // yes, user asked VM to launch debugger

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

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

    59 

    60       os::fork_and_exec(buf);

    61       yes = false;

    62     }

    63   } while (yes);

    64 }

    65 

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

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

    68 

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

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

    71 

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

    73 static int resettedSigflags[NUM_SIGNALS];

    74 static address resettedSighandler[NUM_SIGNALS];

    75 

    76 static void save_signal(int idx, int sig)

    77 {

    78   struct sigaction sa;

    79   sigaction(sig, NULL, &sa);

    80   resettedSigflags[idx]   = sa.sa_flags;

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

    82                               ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)

    83                               : CAST_FROM_FN_PTR(address, sa.sa_handler);

    84 }

    85 

    86 int VMError::get_resetted_sigflags(int sig) {

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

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

    89       return resettedSigflags[i];

    90     }

    91   }

    92   return -1;

    93 }

    94 

    95 address VMError::get_resetted_sighandler(int sig) {

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

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

    98       return resettedSighandler[i];

    99     }

   100   }

   101   return NULL;

   102 }

   103 

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

   105   // unmask current signal

   106   sigset_t newset;

   107   sigemptyset(&newset);

   108   sigaddset(&newset, sig);

   109   // also unmask other synchronous signals

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

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

   112   }

   113   pthread_sigmask(SIG_UNBLOCK, &newset, NULL);

   114 

   115   // support safefetch faults in error handling

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

   117   address const pc = uc ? os::Bsd::ucontext_get_pc(uc) : NULL;

   118 

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

   120     os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));

   121     return;

   122   }

   123 

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

   125 }

   126 

   127 void VMError::reset_signal_handlers() {

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

   129   sigset_t newset;

   130   sigemptyset(&newset);

   131 

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

   133     save_signal(i, SIGNALS[i]);

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

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

   136   }

   137   pthread_sigmask(SIG_UNBLOCK, &newset, NULL);

   138 }