1 /*

     2  * Copyright (c) 2003, 2015, 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 <signal.h>

    34 

    35 #ifdef TARGET_OS_FAMILY_linux

    36 #include <sys/syscall.h>

    37 #include <unistd.h>

    38 #endif

    39 #ifdef TARGET_OS_FAMILY_solaris

    40 #include <thread.h>

    41 #endif

    42 #ifdef TARGET_OS_FAMILY_aix

    43 #include <unistd.h>

    44 #endif

    45 #ifdef TARGET_OS_FAMILY_bsd

    46 #include <sys/syscall.h>

    47 #include <unistd.h>

    48 #endif

    49 

    50 

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

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

    53 

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

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

    56 

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

    58 static int resettedSigflags[NUM_SIGNALS];

    59 static address resettedSighandler[NUM_SIGNALS];

    60 

    61 static void save_signal(int idx, int sig)

    62 {

    63   struct sigaction sa;

    64   sigaction(sig, NULL, &sa);

    65   resettedSigflags[idx]   = sa.sa_flags;

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

    67                               ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)

    68                               : CAST_FROM_FN_PTR(address, sa.sa_handler);

    69 }

    70 

    71 int VMError::get_resetted_sigflags(int sig) {

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

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

    74       return resettedSigflags[i];

    75     }

    76   }

    77   return -1;

    78 }

    79 

    80 address VMError::get_resetted_sighandler(int sig) {

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

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

    83       return resettedSighandler[i];

    84     }

    85   }

    86   return NULL;

    87 }

    88 

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

    90   // unmask current signal

    91   sigset_t newset;

    92   sigemptyset(&newset);

    93   sigaddset(&newset, sig);

    94   // also unmask other synchronous signals

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

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

    97   }

    98   os::Posix::unblock_thread_signal_mask(&newset);

    99 

   100   // support safefetch faults in error handling

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

   102   address const pc = uc ? os::Posix::ucontext_get_pc(uc) : NULL;

   103 

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

   105     os::Posix::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));

   106     return;

   107   }

   108 

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

   110 }

   111 

   112 void VMError::reset_signal_handlers() {

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

   114   sigset_t newset;

   115   sigemptyset(&newset);

   116 

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

   118     save_signal(i, SIGNALS[i]);

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

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

   121   }

   122   os::Posix::unblock_thread_signal_mask(&newset);

   123 

   124 }