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src/java.base/linux/native/libjsig/jsig.c

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*** 1,7 **** /* ! * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. --- 1,8 ---- /* ! * Copyright (c) 2001, 2018, Oracle and/or its affiliates. All rights reserved. ! * Copyright (c) 2012, 2015 SAP SE. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.
*** 20,135 **** * or visit www.oracle.com if you need additional information or have any * questions. * */ - /* CopyrightVersion 1.2 */ - /* This is a special library that should be loaded before libc & * libthread to interpose the signal handler installation functions: * sigaction(), signal(), sigset(). * Used for signal-chaining. See RFE 4381843. */ - #include <signal.h> #include <dlfcn.h> ! #include <pthread.h> #include <stdio.h> #include <stdlib.h> - #include <stdint.h> ! #define bool int ! #define true 1 ! #define false 0 ! ! #define MASK(sig) ((uint64_t)1 << (sig-1)) // 0 is not a signal. ! // Check whether all signals fit into jvmsigs. -1 as MASK shifts by -1. ! #if (64 < NSIG-1) ! #error "Not all signals can be encoded in jvmsigs. Adapt its type!" #endif static struct sigaction sact[NSIG]; /* saved signal handlers */ ! static uint64_t jvmsigs = 0; /* signals used by jvm */ ! /* used to synchronize the installation of signal handlers */ static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; static pthread_t tid = 0; typedef void (*sa_handler_t)(int); typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); ! typedef sa_handler_t (*signal_t)(int, sa_handler_t); typedef int (*sigaction_t)(int, const struct sigaction *, struct sigaction *); ! static signal_t os_signal = 0; /* os's version of signal()/sigset() */ static sigaction_t os_sigaction = 0; /* os's version of sigaction() */ static bool jvm_signal_installing = false; static bool jvm_signal_installed = false; static void signal_lock() { pthread_mutex_lock(&mutex); /* When the jvm is installing its set of signal handlers, threads ! * other than the jvm thread should wait */ if (jvm_signal_installing) { if (tid != pthread_self()) { pthread_cond_wait(&cond, &mutex); } } } static void signal_unlock() { pthread_mutex_unlock(&mutex); } static sa_handler_t call_os_signal(int sig, sa_handler_t disp, bool is_sigset) { if (os_signal == NULL) { if (!is_sigset) { ! os_signal = (signal_t)dlsym(RTLD_NEXT, "signal"); } else { ! os_signal = (signal_t)dlsym(RTLD_NEXT, "sigset"); } if (os_signal == NULL) { printf("%s\n", dlerror()); exit(0); } } ! return (*os_signal)(sig, disp); } ! static void save_signal_handler(int sig, sa_handler_t disp) { sigset_t set; sact[sig].sa_handler = disp; sigemptyset(&set); sact[sig].sa_mask = set; sact[sig].sa_flags = 0; } static sa_handler_t set_signal(int sig, sa_handler_t disp, bool is_sigset) { sa_handler_t oldhandler; bool sigused; signal_lock(); ! sigused = (sig < NSIG) && ((MASK(sig) & jvmsigs) != 0); if (jvm_signal_installed && sigused) { /* jvm has installed its signal handler for this signal. */ /* Save the handler. Don't really install it. */ oldhandler = sact[sig].sa_handler; ! save_signal_handler(sig, disp); signal_unlock(); return oldhandler; ! } else if (sig < NSIG && jvm_signal_installing) { /* jvm is installing its signal handlers. Install the new * handlers and save the old ones. jvm uses sigaction(). * Leave the piece here just in case. */ oldhandler = call_os_signal(sig, disp, is_sigset); ! save_signal_handler(sig, oldhandler); /* Record the signals used by jvm */ ! jvmsigs |= MASK(sig); signal_unlock(); return oldhandler; } else { /* jvm has no relation with this signal (yet). Install the --- 21,200 ---- * or visit www.oracle.com if you need additional information or have any * questions. * */ /* This is a special library that should be loaded before libc & * libthread to interpose the signal handler installation functions: * sigaction(), signal(), sigset(). * Used for signal-chaining. See RFE 4381843. */ #include <dlfcn.h> ! #include <signal.h> #include <stdio.h> #include <stdlib.h> ! #ifdef SOLARIS ! #include <synch.h> ! #include <thread.h> ! #else ! #include <pthread.h> ! #endif ! ! #if (__STDC_VERSION__ >= 199901L) ! #include <stdbool.h> ! #else ! #define bool int ! #define true 1 ! #define false 0 #endif + + #ifndef NSIG + #define NSIG SIGRTMAX + #endif + static struct sigaction sact[NSIG]; /* saved signal handlers */ ! static sigset_t jvmsigs; /* Signals used by jvm. */ ! static __thread bool reentry = false; /* prevent reentry deadlock (per-thread) */ ! /* Used to synchronize the installation of signal handlers. */ ! #ifdef SOLARIS ! static mutex_t mutex = DEFAULTMUTEX; ! static cond_t cond = DEFAULTCV; ! static thread_t tid = 0; ! #else static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; static pthread_cond_t cond = PTHREAD_COND_INITIALIZER; static pthread_t tid = 0; + #endif typedef void (*sa_handler_t)(int); typedef void (*sa_sigaction_t)(int, siginfo_t *, void *); ! typedef sa_handler_t (*signal_function_t)(int, sa_handler_t); typedef int (*sigaction_t)(int, const struct sigaction *, struct sigaction *); ! static signal_function_t os_signal = 0; /* os's version of signal()/sigset() */ static sigaction_t os_sigaction = 0; /* os's version of sigaction() */ static bool jvm_signal_installing = false; static bool jvm_signal_installed = false; static void signal_lock() { + #ifdef SOLARIS + mutex_lock(&mutex); + #else pthread_mutex_lock(&mutex); + #endif /* When the jvm is installing its set of signal handlers, threads ! * other than the jvm thread should wait. */ if (jvm_signal_installing) { + #ifdef SOLARIS + if (tid != thr_self()) { + cond_wait(&cond, &mutex); + } + #else if (tid != pthread_self()) { pthread_cond_wait(&cond, &mutex); } + #endif } } static void signal_unlock() { + #ifdef SOLARIS + mutex_unlock(&mutex); + #else pthread_mutex_unlock(&mutex); + #endif } static sa_handler_t call_os_signal(int sig, sa_handler_t disp, bool is_sigset) { + sa_handler_t res; + if (os_signal == NULL) { if (!is_sigset) { ! #ifdef AIX ! os_signal = signal; ! #else ! os_signal = (signal_function_t)dlsym(RTLD_NEXT, "signal"); ! #endif } else { ! #ifdef AIX ! os_signal = sigset; ! #else ! os_signal = (signal_function_t)dlsym(RTLD_NEXT, "sigset"); ! #endif } if (os_signal == NULL) { printf("%s\n", dlerror()); exit(0); } } ! /* On some OSes like macosx, the OS implementation of signal calls sigaction. ! * Make sure we do not deadlock with ourself. (See JDK-8072147). */ ! reentry = true; ! res = (*os_signal)(sig, disp); ! reentry = false; ! return res; } ! static void save_signal_handler(int sig, sa_handler_t disp, bool is_sigset) { sigset_t set; sact[sig].sa_handler = disp; sigemptyset(&set); sact[sig].sa_mask = set; + if (!is_sigset) { + #ifdef SOLARIS + sact[sig].sa_flags = SA_NODEFER; + if (sig != SIGILL && sig != SIGTRAP && sig != SIGPWR) { + sact[sig].sa_flags |= SA_RESETHAND; + } + #else sact[sig].sa_flags = 0; + #endif + } else { + sact[sig].sa_flags = 0; + } } static sa_handler_t set_signal(int sig, sa_handler_t disp, bool is_sigset) { sa_handler_t oldhandler; bool sigused; + bool sigblocked; signal_lock(); ! sigused = sigismember(&jvmsigs, sig); if (jvm_signal_installed && sigused) { /* jvm has installed its signal handler for this signal. */ /* Save the handler. Don't really install it. */ + if (is_sigset) { + sigblocked = sigismember(&(sact[sig].sa_mask), sig); + } oldhandler = sact[sig].sa_handler; ! save_signal_handler(sig, disp, is_sigset); ! ! #ifdef SOLARIS ! if (is_sigset && sigblocked) { ! /* We won't honor the SIG_HOLD request to change the signal mask */ ! oldhandler = SIG_HOLD; ! } ! #endif signal_unlock(); return oldhandler; ! } else if (jvm_signal_installing) { /* jvm is installing its signal handlers. Install the new * handlers and save the old ones. jvm uses sigaction(). * Leave the piece here just in case. */ oldhandler = call_os_signal(sig, disp, is_sigset); ! save_signal_handler(sig, oldhandler, is_sigset); /* Record the signals used by jvm */ ! sigaddset(&jvmsigs, sig); signal_unlock(); return oldhandler; } else { /* jvm has no relation with this signal (yet). Install the
*** 144,160 **** sa_handler_t signal(int sig, sa_handler_t disp) { return set_signal(sig, disp, false); } sa_handler_t sigset(int sig, sa_handler_t disp) { return set_signal(sig, disp, true); ! } static int call_os_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { if (os_sigaction == NULL) { os_sigaction = (sigaction_t)dlsym(RTLD_NEXT, "sigaction"); if (os_sigaction == NULL) { printf("%s\n", dlerror()); exit(0); } } --- 209,234 ---- sa_handler_t signal(int sig, sa_handler_t disp) { return set_signal(sig, disp, false); } sa_handler_t sigset(int sig, sa_handler_t disp) { + #ifdef _ALLBSD_SOURCE + printf("sigset() is not supported by BSD"); + exit(0); + #else return set_signal(sig, disp, true); ! #endif ! } static int call_os_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { if (os_sigaction == NULL) { + #ifdef AIX + os_sigaction = sigaction; + #else os_sigaction = (sigaction_t)dlsym(RTLD_NEXT, "sigaction"); + #endif if (os_sigaction == NULL) { printf("%s\n", dlerror()); exit(0); } }
*** 164,176 **** int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { int res; bool sigused; struct sigaction oldAct; signal_lock(); ! sigused = (sig < NSIG) && ((MASK(sig) & jvmsigs) != 0); if (jvm_signal_installed && sigused) { /* jvm has installed its signal handler for this signal. */ /* Save the handler. Don't really install it. */ if (oact != NULL) { *oact = sact[sig]; --- 238,254 ---- int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) { int res; bool sigused; struct sigaction oldAct; + if (reentry) { + return call_os_sigaction(sig, act, oact); + } + signal_lock(); ! sigused = sigismember(&jvmsigs, sig); if (jvm_signal_installed && sigused) { /* jvm has installed its signal handler for this signal. */ /* Save the handler. Don't really install it. */ if (oact != NULL) { *oact = sact[sig];
*** 179,199 **** sact[sig] = *act; } signal_unlock(); return 0; ! } else if (sig < NSIG && jvm_signal_installing) { /* jvm is installing its signal handlers. Install the new * handlers and save the old ones. */ res = call_os_sigaction(sig, act, &oldAct); sact[sig] = oldAct; if (oact != NULL) { *oact = oldAct; } ! /* Record the signals used by jvm */ ! jvmsigs |= MASK(sig); signal_unlock(); return res; } else { /* jvm has no relation with this signal (yet). Install the --- 257,277 ---- sact[sig] = *act; } signal_unlock(); return 0; ! } else if (jvm_signal_installing) { /* jvm is installing its signal handlers. Install the new * handlers and save the old ones. */ res = call_os_sigaction(sig, act, &oldAct); sact[sig] = oldAct; if (oact != NULL) { *oact = oldAct; } ! /* Record the signals used by jvm. */ ! sigaddset(&jvmsigs, sig); signal_unlock(); return res; } else { /* jvm has no relation with this signal (yet). Install the
*** 203,230 **** signal_unlock(); return res; } } ! /* The three functions for the jvm to call into */ void JVM_begin_signal_setting() { signal_lock(); jvm_signal_installing = true; tid = pthread_self(); signal_unlock(); } void JVM_end_signal_setting() { signal_lock(); jvm_signal_installed = true; jvm_signal_installing = false; pthread_cond_broadcast(&cond); signal_unlock(); } struct sigaction *JVM_get_signal_action(int sig) { /* Does race condition make sense here? */ ! if ((MASK(sig) & jvmsigs) != 0) { return &sact[sig]; } return NULL; } --- 281,317 ---- signal_unlock(); return res; } } ! /* The three functions for the jvm to call into. */ void JVM_begin_signal_setting() { signal_lock(); + sigemptyset(&jvmsigs); jvm_signal_installing = true; + #ifdef SOLARIS + tid = thr_self(); + #else tid = pthread_self(); + #endif signal_unlock(); } void JVM_end_signal_setting() { signal_lock(); jvm_signal_installed = true; jvm_signal_installing = false; + #ifdef SOLARIS + cond_broadcast(&cond); + #else pthread_cond_broadcast(&cond); + #endif signal_unlock(); } struct sigaction *JVM_get_signal_action(int sig) { /* Does race condition make sense here? */ ! if (sigismember(&jvmsigs, sig)) { return &sact[sig]; } return NULL; }
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