1 /*
   2  * Copyright (c) 1998, 2007, 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 "incls/_precompiled.incl"
  26 #include "incls/_jvm_solaris.cpp.incl"
  27 
  28 #include <signal.h>
  29 
  30 // sun.misc.Signal ///////////////////////////////////////////////////////////
  31 // Signal code is mostly copied from classic vm, signals_md.c   1.4 98/08/23
  32 /*
  33  * This function is included primarily as a debugging aid. If Java is
  34  * running in a console window, then pressing <CTRL-\\> will cause
  35  * the current state of all active threads and monitors to be written
  36  * to the console window.
  37  */
  38 
  39 JVM_ENTRY_NO_ENV(void*, JVM_RegisterSignal(jint sig, void* handler))
  40   // Copied from classic vm
  41   // signals_md.c       1.4 98/08/23
  42   void* newHandler = handler == (void *)2
  43                    ? os::user_handler()
  44                    : handler;
  45   switch (sig) {
  46     /* The following are already used by the VM. */
  47     case SIGFPE:
  48     case SIGILL:
  49     case SIGSEGV:
  50 
  51     /* The following signal is used by the VM to dump thread stacks unless
  52        ReduceSignalUsage is set, in which case the user is allowed to set
  53        his own _native_ handler for this signal; thus, in either case,
  54        we do not allow JVM_RegisterSignal to change the handler. */
  55     case BREAK_SIGNAL:
  56       return (void *)-1;
  57 
  58     /* The following signals are used for Shutdown Hooks support. However, if
  59        ReduceSignalUsage (-Xrs) is set, Shutdown Hooks must be invoked via
  60        System.exit(), Java is not allowed to use these signals, and the the
  61        user is allowed to set his own _native_ handler for these signals and
  62        invoke System.exit() as needed. Terminator.setup() is avoiding
  63        registration of these signals when -Xrs is present.
  64        - If the HUP signal is ignored (from the nohup) command, then Java
  65          is not allowed to use this signal.
  66      */
  67     case SHUTDOWN1_SIGNAL:
  68     case SHUTDOWN2_SIGNAL:
  69     case SHUTDOWN3_SIGNAL:
  70       if (ReduceSignalUsage) return (void*)-1;
  71       if (os::Solaris::is_sig_ignored(sig)) return (void*)1;
  72   }
  73 
  74   /* Check parameterized signals. Don't allow sharing of our interrupt signal */
  75   if (sig == os::Solaris::SIGinterrupt()) {
  76       return (void *)-1;
  77   }
  78 
  79   void* oldHandler = os::signal(sig, newHandler);
  80   if (oldHandler == os::user_handler()) {
  81       return (void *)2;
  82   } else {
  83       return oldHandler;
  84   }
  85 JVM_END
  86 
  87 
  88 JVM_ENTRY_NO_ENV(jboolean, JVM_RaiseSignal(jint sig))
  89   if (ReduceSignalUsage) {
  90     // do not allow SHUTDOWN1_SIGNAL,SHUTDOWN2_SIGNAL,SHUTDOWN3_SIGNAL,
  91     // BREAK_SIGNAL to be raised when ReduceSignalUsage is set, since
  92     // no handler for them is actually registered in JVM or via
  93     // JVM_RegisterSignal.
  94     if (sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
  95         sig == SHUTDOWN3_SIGNAL || sig == BREAK_SIGNAL) {
  96       return JNI_FALSE;
  97     }
  98   }
  99   else if ((sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
 100             sig == SHUTDOWN3_SIGNAL) && os::Solaris::is_sig_ignored(sig)) {
 101     // do not allow SHUTDOWN1_SIGNAL to be raised when SHUTDOWN1_SIGNAL
 102     // is ignored, since no handler for them is actually registered in JVM
 103     // or via JVM_RegisterSignal.
 104     // This also applies for SHUTDOWN2_SIGNAL and SHUTDOWN3_SIGNAL
 105     return JNI_FALSE;
 106   }
 107 
 108   os::signal_raise(sig);
 109   return JNI_TRUE;
 110 JVM_END
 111 
 112 
 113 /*
 114   All the defined signal names for Solaris are defined by str2sig().
 115 
 116   NOTE that not all of these names are accepted by our Java implementation
 117 
 118   Via an existing claim by the VM, sigaction restrictions, or
 119   the "rules of Unix" some of these names will be rejected at runtime.
 120   For example the VM sets up to handle USR1, sigaction returns EINVAL for
 121   CANCEL, and Solaris simply doesn't allow catching of KILL.
 122 
 123   Here are the names currently accepted by a user of sun.misc.Signal with
 124   1.4.1 (ignoring potential interaction with use of chaining, etc):
 125 
 126       HUP, INT, TRAP, IOT, ABRT, EMT, BUS, SYS, PIPE, ALRM, TERM, USR2,
 127       CLD, CHLD, PWR, WINCH, URG, POLL, IO, TSTP, CONT, TTIN, TTOU, VTALRM,
 128       PROF, XCPU, XFSZ, FREEZE, THAW, LOST
 129 */
 130 
 131 JVM_ENTRY_NO_ENV(jint, JVM_FindSignal(const char *name))
 132 
 133   int sig;
 134 
 135   /* return the named signal's number */
 136 
 137   if(str2sig(name, &sig))
 138     return -1;
 139   else
 140     return sig;
 141 
 142 JVM_END
 143 
 144 
 145 //Reconciliation History
 146 // 1.4 98/10/07 13:39:41 jvm_win32.cpp
 147 // 1.6 99/06/22 16:39:00 jvm_win32.cpp
 148 //End