1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/os/solaris/vm/jsig.c Wed Apr 27 01:25:04 2016 +0800 1.3 @@ -0,0 +1,273 @@ 1.4 +/* 1.5 + * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. 1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 1.7 + * 1.8 + * This code is free software; you can redistribute it and/or modify it 1.9 + * under the terms of the GNU General Public License version 2 only, as 1.10 + * published by the Free Software Foundation. 1.11 + * 1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT 1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 1.15 + * version 2 for more details (a copy is included in the LICENSE file that 1.16 + * accompanied this code). 1.17 + * 1.18 + * You should have received a copy of the GNU General Public License version 1.19 + * 2 along with this work; if not, write to the Free Software Foundation, 1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 1.21 + * 1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 1.23 + * or visit www.oracle.com if you need additional information or have any 1.24 + * questions. 1.25 + * 1.26 + */ 1.27 + 1.28 +/* CopyrightVersion 1.2 */ 1.29 + 1.30 +/* This is a special library that should be loaded before libc & 1.31 + * libthread to interpose the signal handler installation functions: 1.32 + * sigaction(), signal(), sigset(). 1.33 + * Used for signal-chaining. See RFE 4381843. 1.34 + */ 1.35 + 1.36 +#include <stdlib.h> 1.37 +#include <stdio.h> 1.38 +#include <string.h> 1.39 +#include <signal.h> 1.40 +#include <dlfcn.h> 1.41 +#include <thread.h> 1.42 +#include <synch.h> 1.43 +#include "jvm_solaris.h" 1.44 + 1.45 +#define bool int 1.46 +#define true 1 1.47 +#define false 0 1.48 + 1.49 +static struct sigaction *sact = (struct sigaction *)NULL; /* saved signal handlers */ 1.50 +static sigset_t jvmsigs; 1.51 + 1.52 +/* used to synchronize the installation of signal handlers */ 1.53 +static mutex_t mutex = DEFAULTMUTEX; 1.54 +static cond_t cond = DEFAULTCV; 1.55 +static thread_t tid = 0; 1.56 + 1.57 +typedef void (*sa_handler_t)(int); 1.58 +typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); 1.59 +typedef sa_handler_t (*signal_t)(int, sa_handler_t); 1.60 +typedef int (*sigaction_t)(int, const struct sigaction *, struct sigaction *); 1.61 + 1.62 +static signal_t os_signal = 0; /* os's version of signal()/sigset() */ 1.63 +static sigaction_t os_sigaction = 0; /* os's version of sigaction() */ 1.64 + 1.65 +static bool jvm_signal_installing = false; 1.66 +static bool jvm_signal_installed = false; 1.67 + 1.68 + 1.69 +/* assume called within signal_lock */ 1.70 +static void allocate_sact() { 1.71 + size_t maxsignum; 1.72 + maxsignum = SIGRTMAX; 1.73 + if (sact == NULL) { 1.74 + sact = (struct sigaction *)malloc((maxsignum+1) * (size_t)sizeof(struct sigaction)); 1.75 + memset(sact, 0, (maxsignum+1) * (size_t)sizeof(struct sigaction)); 1.76 + } 1.77 + 1.78 + if (sact == NULL) { 1.79 + printf("%s\n", "libjsig.so unable to allocate memory"); 1.80 + exit(0); 1.81 + } 1.82 + 1.83 + sigemptyset(&jvmsigs); 1.84 +} 1.85 + 1.86 +static void signal_lock() { 1.87 + mutex_lock(&mutex); 1.88 + /* When the jvm is installing its set of signal handlers, threads 1.89 + * other than the jvm thread should wait */ 1.90 + if (jvm_signal_installing) { 1.91 + if (tid != thr_self()) { 1.92 + cond_wait(&cond, &mutex); 1.93 + } 1.94 + } 1.95 +} 1.96 + 1.97 +static void signal_unlock() { 1.98 + mutex_unlock(&mutex); 1.99 +} 1.100 + 1.101 +static sa_handler_t call_os_signal(int sig, sa_handler_t disp, 1.102 + bool is_sigset) { 1.103 + if (os_signal == NULL) { 1.104 + if (!is_sigset) { 1.105 + os_signal = (signal_t)dlsym(RTLD_NEXT, "signal"); 1.106 + } else { 1.107 + os_signal = (signal_t)dlsym(RTLD_NEXT, "sigset"); 1.108 + } 1.109 + if (os_signal == NULL) { 1.110 + printf("%s\n", dlerror()); 1.111 + exit(0); 1.112 + } 1.113 + } 1.114 + return (*os_signal)(sig, disp); 1.115 +} 1.116 + 1.117 +static void save_signal_handler(int sig, sa_handler_t disp, bool is_sigset) { 1.118 + sigset_t set; 1.119 + if (sact == NULL) { 1.120 + allocate_sact(); 1.121 + } 1.122 + sact[sig].sa_handler = disp; 1.123 + sigemptyset(&set); 1.124 + sact[sig].sa_mask = set; 1.125 + if (!is_sigset) { 1.126 + sact[sig].sa_flags = SA_NODEFER; 1.127 + if (sig != SIGILL && sig != SIGTRAP && sig != SIGPWR) { 1.128 + sact[sig].sa_flags |= SA_RESETHAND; 1.129 + } 1.130 + } else { 1.131 + sact[sig].sa_flags = 0; 1.132 + } 1.133 +} 1.134 + 1.135 +static sa_handler_t set_signal(int sig, sa_handler_t disp, bool is_sigset) { 1.136 + sa_handler_t oldhandler; 1.137 + bool sigblocked; 1.138 + 1.139 + signal_lock(); 1.140 + if (sact == NULL) { 1.141 + allocate_sact(); 1.142 + } 1.143 + 1.144 + if (jvm_signal_installed && sigismember(&jvmsigs, sig)) { 1.145 + /* jvm has installed its signal handler for this signal. */ 1.146 + /* Save the handler. Don't really install it. */ 1.147 + if (is_sigset) { 1.148 + /* We won't honor the SIG_HOLD request to change the signal mask */ 1.149 + sigblocked = sigismember(&(sact[sig].sa_mask), sig); 1.150 + } 1.151 + oldhandler = sact[sig].sa_handler; 1.152 + save_signal_handler(sig, disp, is_sigset); 1.153 + 1.154 + if (is_sigset && sigblocked) { 1.155 + oldhandler = SIG_HOLD; 1.156 + } 1.157 + 1.158 + signal_unlock(); 1.159 + return oldhandler; 1.160 + } else if (jvm_signal_installing) { 1.161 + /* jvm is installing its signal handlers. Install the new 1.162 + * handlers and save the old ones. jvm uses sigaction(). 1.163 + * Leave the piece here just in case. */ 1.164 + oldhandler = call_os_signal(sig, disp, is_sigset); 1.165 + save_signal_handler(sig, oldhandler, is_sigset); 1.166 + 1.167 + /* Record the signals used by jvm */ 1.168 + sigaddset(&jvmsigs, sig); 1.169 + 1.170 + signal_unlock(); 1.171 + return oldhandler; 1.172 + } else { 1.173 + /* jvm has no relation with this signal (yet). Install the 1.174 + * the handler. */ 1.175 + oldhandler = call_os_signal(sig, disp, is_sigset); 1.176 + 1.177 + signal_unlock(); 1.178 + return oldhandler; 1.179 + } 1.180 +} 1.181 + 1.182 +sa_handler_t signal(int sig, sa_handler_t disp) { 1.183 + return set_signal(sig, disp, false); 1.184 +} 1.185 + 1.186 +sa_handler_t sigset(int sig, sa_handler_t disp) { 1.187 + return set_signal(sig, disp, true); 1.188 +} 1.189 + 1.190 +static int call_os_sigaction(int sig, const struct sigaction *act, 1.191 + struct sigaction *oact) { 1.192 + if (os_sigaction == NULL) { 1.193 + os_sigaction = (sigaction_t)dlsym(RTLD_NEXT, "sigaction"); 1.194 + if (os_sigaction == NULL) { 1.195 + printf("%s\n", dlerror()); 1.196 + exit(0); 1.197 + } 1.198 + } 1.199 + return (*os_sigaction)(sig, act, oact); 1.200 +} 1.201 + 1.202 +int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { 1.203 + int res; 1.204 + struct sigaction oldAct; 1.205 + 1.206 + signal_lock(); 1.207 + 1.208 + if (sact == NULL ) { 1.209 + allocate_sact(); 1.210 + } 1.211 + if (jvm_signal_installed && sigismember(&jvmsigs, sig)) { 1.212 + /* jvm has installed its signal handler for this signal. */ 1.213 + /* Save the handler. Don't really install it. */ 1.214 + if (oact != NULL) { 1.215 + *oact = sact[sig]; 1.216 + } 1.217 + if (act != NULL) { 1.218 + sact[sig] = *act; 1.219 + } 1.220 + 1.221 + signal_unlock(); 1.222 + return 0; 1.223 + } else if (jvm_signal_installing) { 1.224 + /* jvm is installing its signal handlers. Install the new 1.225 + * handlers and save the old ones. */ 1.226 + res = call_os_sigaction(sig, act, &oldAct); 1.227 + sact[sig] = oldAct; 1.228 + if (oact != NULL) { 1.229 + *oact = oldAct; 1.230 + } 1.231 + 1.232 + /* Record the signals used by jvm */ 1.233 + sigaddset(&jvmsigs, sig); 1.234 + 1.235 + signal_unlock(); 1.236 + return res; 1.237 + } else { 1.238 + /* jvm has no relation with this signal (yet). Install the 1.239 + * the handler. */ 1.240 + res = call_os_sigaction(sig, act, oact); 1.241 + 1.242 + signal_unlock(); 1.243 + return res; 1.244 + } 1.245 +} 1.246 + 1.247 +/* The four functions for the jvm to call into */ 1.248 +void JVM_begin_signal_setting() { 1.249 + signal_lock(); 1.250 + jvm_signal_installing = true; 1.251 + tid = thr_self(); 1.252 + signal_unlock(); 1.253 +} 1.254 + 1.255 +void JVM_end_signal_setting() { 1.256 + signal_lock(); 1.257 + jvm_signal_installed = true; 1.258 + jvm_signal_installing = false; 1.259 + cond_broadcast(&cond); 1.260 + signal_unlock(); 1.261 +} 1.262 + 1.263 +struct sigaction *JVM_get_signal_action(int sig) { 1.264 + if (sact == NULL) { 1.265 + allocate_sact(); 1.266 + } 1.267 + /* Does race condition make sense here? */ 1.268 + if (sigismember(&jvmsigs, sig)) { 1.269 + return &sact[sig]; 1.270 + } 1.271 + return NULL; 1.272 +} 1.273 + 1.274 +int JVM_get_libjsig_version() { 1.275 + return JSIG_VERSION_1_4_1; 1.276 +}