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src/java.base/unix/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.
*** 20,76 ****
* 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);
}
}
--- 21,78 ----
* 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 <errno.h>
#include <pthread.h>
+ #include <signal.h>
#include <stdio.h>
#include <stdlib.h>
! #if (__STDC_VERSION__ >= 199901L)
! #include <stdbool.h>
! #else
! #define bool int
! #define true 1
! #define false 0
#endif
+
static struct sigaction sact[NSIG]; /* saved signal handlers */
! static sigset_t jvmsigs; /* Signals used by jvm. */
!
! #ifdef MACOSX
! static __thread bool reentry = false; /* prevent reentry deadlock (per-thread) */
! #endif
! /* 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_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() {
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);
}
}
*** 80,135 ****
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
--- 82,174 ----
pthread_mutex_unlock(&mutex);
}
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) {
! os_signal = (signal_function_t)dlsym(RTLD_NEXT, "signal");
} else {
! os_signal = (signal_function_t)dlsym(RTLD_NEXT, "sigset");
}
if (os_signal == NULL) {
printf("%s\n", dlerror());
exit(0);
}
}
!
! #ifdef MACOSX
! /* On macosx, the OS implementation of signal calls sigaction.
! * Make sure we do not deadlock with ourself. (See JDK-8072147). */
! reentry = true;
! #endif
!
! res = (*os_signal)(sig, disp);
!
! #ifdef MACOSX
! reentry = false;
! #endif
!
! 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
*** 140,156 ****
return oldhandler;
}
}
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) {
--- 179,210 ----
return oldhandler;
}
}
sa_handler_t signal(int sig, sa_handler_t disp) {
+ if (sig < 0 || sig >= NSIG) {
+ errno = EINVAL;
+ return SIG_ERR;
+ }
+
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
! if (sig < 0 || sig >= NSIG) {
! errno = EINVAL;
! return (sa_handler_t)-1;
}
+ 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) {
os_sigaction = (sigaction_t)dlsym(RTLD_NEXT, "sigaction");
if (os_sigaction == NULL) {
*** 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];
--- 218,241 ----
int sigaction(int sig, const struct sigaction *act, struct sigaction *oact) {
int res;
bool sigused;
struct sigaction oldAct;
+ if (sig < 0 || sig >= NSIG) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ #ifdef MACOSX
+ if (reentry) {
+ return call_os_sigaction(sig, act, oact);
+ }
+ #endif
+
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
--- 244,264 ----
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
*** 203,215 ****
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();
}
--- 268,281 ----
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;
tid = pthread_self();
signal_unlock();
}
*** 221,230 ****
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;
}
--- 287,296 ----
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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