1 /*
2 * Copyright (c) 2003, 2010, 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 #include "precompiled.hpp"
26 #include "runtime/arguments.hpp"
27 #include "runtime/os.hpp"
28 #include "runtime/thread.hpp"
29 #include "utilities/vmError.hpp"
30
31 #include <sys/types.h>
32 #include <sys/wait.h>
33 #include <sys/syscall.h>
34 #include <unistd.h>
35 #include <signal.h>
36
37 void VMError::show_message_box(char *buf, int buflen) {
38 bool yes;
39 do {
40 error_string(buf, buflen);
41 int len = (int)strlen(buf);
42 char *p = &buf[len];
43
44 jio_snprintf(p, buflen - len,
45 "\n\n"
46 "Do you want to debug the problem?\n\n"
47 "To debug, run 'gdb /proc/%d/exe %d'; then switch to thread " INTX_FORMAT " (" INTPTR_FORMAT ")\n"
48 "Enter 'yes' to launch gdb automatically (PATH must include gdb)\n"
49 "Otherwise, press RETURN to abort...",
50 os::current_process_id(), os::current_process_id(),
51 os::current_thread_id(), os::current_thread_id());
52
53 yes = os::message_box("Unexpected Error", buf);
54
55 if (yes) {
56 // yes, user asked VM to launch debugger
57 jio_snprintf(buf, buflen, "gdb /proc/%d/exe %d",
58 os::current_process_id(), os::current_process_id());
59
60 os::fork_and_exec(buf);
61 yes = false;
62 }
63 } while (yes);
64 }
65
66 // handle all synchronous program error signals which may happen during error
67 // reporting. They must be unblocked, caught, handled.
68
69 static const int SIGNALS[] = { SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP }; // add more if needed
70 static const int NUM_SIGNALS = sizeof(SIGNALS) / sizeof(int);
71
72 // Space for our "saved" signal flags and handlers
73 static int resettedSigflags[NUM_SIGNALS];
74 static address resettedSighandler[NUM_SIGNALS];
75
76 static void save_signal(int idx, int sig)
77 {
78 struct sigaction sa;
79 sigaction(sig, NULL, &sa);
80 resettedSigflags[idx] = sa.sa_flags;
81 resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO)
82 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
83 : CAST_FROM_FN_PTR(address, sa.sa_handler);
84 }
85
86 int VMError::get_resetted_sigflags(int sig) {
87 for (int i = 0; i < NUM_SIGNALS; i++) {
88 if (SIGNALS[i] == sig) {
89 return resettedSigflags[i];
90 }
91 }
92 return -1;
93 }
94
95 address VMError::get_resetted_sighandler(int sig) {
96 for (int i = 0; i < NUM_SIGNALS; i++) {
97 if (SIGNALS[i] == sig) {
98 return resettedSighandler[i];
99 }
100 }
101 return NULL;
102 }
103
104 static void crash_handler(int sig, siginfo_t* info, void* ucVoid) {
105 // unmask current signal
106 sigset_t newset;
107 sigemptyset(&newset);
108 sigaddset(&newset, sig);
109 // also unmask other synchronous signals
110 for (int i = 0; i < NUM_SIGNALS; i++) {
111 sigaddset(&newset, SIGNALS[i]);
112 }
113 pthread_sigmask(SIG_UNBLOCK, &newset, NULL);
114
115 // support safefetch faults in error handling
116 ucontext_t* const uc = (ucontext_t*) ucVoid;
117 address const pc = uc ? os::Bsd::ucontext_get_pc(uc) : NULL;
118
119 if (uc && pc && StubRoutines::is_safefetch_fault(pc)) {
120 os::Bsd::ucontext_set_pc(uc, StubRoutines::continuation_for_safefetch_fault(pc));
121 return;
122 }
123
124 VMError err(NULL, sig, pc, info, ucVoid);
125 err.report_and_die();
126 }
127
128 void VMError::reset_signal_handlers() {
129 // install signal handlers for all synchronous program error signals
130 sigset_t newset;
131 sigemptyset(&newset);
132
133 for (int i = 0; i < NUM_SIGNALS; i++) {
134 save_signal(i, SIGNALS[i]);
135 os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler));
136 sigaddset(&newset, SIGNALS[i]);
137 }
138 pthread_sigmask(SIG_UNBLOCK, &newset, NULL);
139 }