1 /*
2 * Copyright (c) 1999, 2016, 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 *
79 static void print_signal_set_short(outputStream* st, const sigset_t* set);
80
81 // unblocks the signal masks for current thread
82 static int unblock_thread_signal_mask(const sigset_t *set);
83
84 // Writes a one-line description of a combination of sigaction.sa_flags
85 // into a user provided buffer. Returns that buffer.
86 static const char* describe_sa_flags(int flags, char* buffer, size_t size);
87
88 // Prints a one-line description of a combination of sigaction.sa_flags.
89 static void print_sa_flags(outputStream* st, int flags);
90
91 static address ucontext_get_pc(const ucontext_t* ctx);
92 // Set PC into context. Needed for continuation after signal.
93 static void ucontext_set_pc(ucontext_t* ctx, address pc);
94
95 // Helper function; describes pthread attributes as short string. String is written
96 // to buf with len buflen; buf is returned.
97 static char* describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr);
98
99 };
100
101 /*
102 * Crash protection for the watcher thread. Wrap the callback
103 * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
104 * back.
105 * To be able to use this - don't take locks, don't rely on destructors,
106 * don't make OS library calls, don't allocate memory, don't print,
107 * don't call code that could leave the heap / memory in an inconsistent state,
108 * or anything else where we are not in control if we suddenly jump out.
109 */
110 class WatcherThreadCrashProtection : public StackObj {
111 public:
112 WatcherThreadCrashProtection();
113 bool call(os::CrashProtectionCallback& cb);
114
115 static void check_crash_protection(int signal, Thread* thread);
116 private:
117 void restore();
118 sigjmp_buf _jmpbuf;
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1 /*
2 * Copyright (c) 1999, 2017, 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 *
79 static void print_signal_set_short(outputStream* st, const sigset_t* set);
80
81 // unblocks the signal masks for current thread
82 static int unblock_thread_signal_mask(const sigset_t *set);
83
84 // Writes a one-line description of a combination of sigaction.sa_flags
85 // into a user provided buffer. Returns that buffer.
86 static const char* describe_sa_flags(int flags, char* buffer, size_t size);
87
88 // Prints a one-line description of a combination of sigaction.sa_flags.
89 static void print_sa_flags(outputStream* st, int flags);
90
91 static address ucontext_get_pc(const ucontext_t* ctx);
92 // Set PC into context. Needed for continuation after signal.
93 static void ucontext_set_pc(ucontext_t* ctx, address pc);
94
95 // Helper function; describes pthread attributes as short string. String is written
96 // to buf with len buflen; buf is returned.
97 static char* describe_pthread_attr(char* buf, size_t buflen, const pthread_attr_t* attr);
98
99 // A safe implementation of realpath which will not cause a buffer overflow if the resolved path
100 // is longer than PATH_MAX.
101 // On success, returns 'outbuf', which now contains the path.
102 // On error, it will return NULL and set errno. The content of 'outbuf' is undefined.
103 // On truncation error ( 'outbuf' too small), it will return NULL and set errno to ENAMETOOLONG.
104 static char* realpath(const char* filename, char* outbuf, size_t outbuflen);
105
106 };
107
108 /*
109 * Crash protection for the watcher thread. Wrap the callback
110 * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp
111 * back.
112 * To be able to use this - don't take locks, don't rely on destructors,
113 * don't make OS library calls, don't allocate memory, don't print,
114 * don't call code that could leave the heap / memory in an inconsistent state,
115 * or anything else where we are not in control if we suddenly jump out.
116 */
117 class WatcherThreadCrashProtection : public StackObj {
118 public:
119 WatcherThreadCrashProtection();
120 bool call(os::CrashProtectionCallback& cb);
121
122 static void check_crash_protection(int signal, Thread* thread);
123 private:
124 void restore();
125 sigjmp_buf _jmpbuf;
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