1 /* 2 * Copyright (c) 1999, 2019, 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 #ifndef OS_POSIX_VM_OS_POSIX_HPP 26 #define OS_POSIX_VM_OS_POSIX_HPP 27 class Posix { 28 friend class os; 29 30 protected: 31 static void print_distro_info(outputStream* st); 32 static void print_rlimit_info(outputStream* st); 33 static void print_uname_info(outputStream* st); 34 static void print_libversion_info(outputStream* st); 35 static void print_load_average(outputStream* st); 36 37 public: 38 39 // Returns true if signal is valid. 40 static bool is_valid_signal(int sig); 41 42 // Helper function, returns a string (e.g. "SIGILL") for a signal. 43 // Returned string is a constant. For unknown signals "UNKNOWN" is returned. 44 static const char* get_signal_name(int sig, char* out, size_t outlen); 45 46 // Returns one-line short description of a signal set in a user provided buffer. 47 static const char* describe_signal_set_short(const sigset_t* set, char* buffer, size_t size); 48 49 // Prints a short one-line description of a signal set. 50 static void print_signal_set_short(outputStream* st, const sigset_t* set); 51 52 // Writes a one-line description of a combination of sigaction.sa_flags 53 // into a user provided buffer. Returns that buffer. 54 static const char* describe_sa_flags(int flags, char* buffer, size_t size); 55 56 // Prints a one-line description of a combination of sigaction.sa_flags. 57 static void print_sa_flags(outputStream* st, int flags); 58 59 // A POSIX conform, platform-independend siginfo print routine. 60 static void print_siginfo_brief(outputStream* os, const siginfo_t* si); 61 62 }; 63 64 /* 65 * Crash protection utility used by JFR. Wrap the callback 66 * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp 67 * back. 68 * To be able to use this - don't take locks, don't rely on destructors, 69 * don't make OS library calls, don't allocate memory, don't print, 70 * don't call code that could leave the heap / memory in an inconsistent state, 71 * or anything else where we are not in control if we suddenly jump out. 72 */ 73 class ThreadCrashProtection : public StackObj { 74 public: 75 static bool is_crash_protected(Thread* thr) { 76 return _crash_protection != NULL && _protected_thread == thr; 77 } 78 79 ThreadCrashProtection(); 80 bool call(os::CrashProtectionCallback& cb); 81 82 static void check_crash_protection(int signal, Thread* thread); 83 private: 84 static Thread* _protected_thread; 85 static ThreadCrashProtection* _crash_protection; 86 static volatile intptr_t _crash_mux; 87 void restore(); 88 sigjmp_buf _jmpbuf; 89 }; 90 91 /* 92 * Crash protection for the watcher thread. Wrap the callback 93 * with a sigsetjmp and in case of a SIGSEGV/SIGBUS we siglongjmp 94 * back. 95 * To be able to use this - don't take locks, don't rely on destructors, 96 * don't make OS library calls, don't allocate memory, don't print, 97 * don't call code that could leave the heap / memory in an inconsistent state, 98 * or anything else where we are not in control if we suddenly jump out. 99 */ 100 class WatcherThreadCrashProtection : public StackObj { 101 public: 102 WatcherThreadCrashProtection(); 103 bool call(os::CrashProtectionCallback& cb); 104 105 static void check_crash_protection(int signal, Thread* thread); 106 private: 107 void restore(); 108 sigjmp_buf _jmpbuf; 109 }; 110 111 #endif // OS_POSIX_VM_OS_POSIX_HPP