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 // Space for our "saved" signal flags and handlers
67 static int resettedSigflags[2];
68 static address resettedSighandler[2];
69
70 static void save_signal(int idx, int sig)
71 {
72 struct sigaction sa;
73 sigaction(sig, NULL, &sa);
74 resettedSigflags[idx] = sa.sa_flags;
75 resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO)
76 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
77 : CAST_FROM_FN_PTR(address, sa.sa_handler);
78 }
79
80 int VMError::get_resetted_sigflags(int sig) {
81 if(SIGSEGV == sig) {
82 return resettedSigflags[0];
83 } else if(SIGBUS == sig) {
84 return resettedSigflags[1];
85 }
86 return -1;
87 }
88
89 address VMError::get_resetted_sighandler(int sig) {
90 if(SIGSEGV == sig) {
91 return resettedSighandler[0];
92 } else if(SIGBUS == sig) {
93 return resettedSighandler[1];
94 }
95 return NULL;
96 }
97
98 static void crash_handler(int sig, siginfo_t* info, void* ucVoid) {
99 // unmask current signal
100 sigset_t newset;
101 sigemptyset(&newset);
102 sigaddset(&newset, sig);
103 sigprocmask(SIG_UNBLOCK, &newset, NULL);
104
105 VMError err(NULL, sig, NULL, info, ucVoid);
106 err.report_and_die();
107 }
108
109 void VMError::reset_signal_handlers() {
110 // Save sigflags for resetted signals
111 save_signal(0, SIGSEGV);
112 save_signal(1, SIGBUS);
113 os::signal(SIGSEGV, CAST_FROM_FN_PTR(void *, crash_handler));
114 os::signal(SIGBUS, CAST_FROM_FN_PTR(void *, crash_handler));
115 }
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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 // Note that in the hotspot signal handlers are installed with a fully filled
70 // signal mask, i.e. upon delivery all signals - also synchronous error signals
71 // - are blocked. For synchronous error signals this is deadly - program will
72 // hang or be ended immediately if secondary errors happend during error
73 // reporting.
74
75 static const int SIGNALS[] = { SIGSEGV, SIGBUS, SIGILL, SIGFPE, SIGTRAP }; // add more if needed
76 static const int NUM_SIGNALS = sizeof(SIGNALS) / sizeof(int);
77
78 // Space for our "saved" signal flags and handlers
79 static int resettedSigflags[NUM_SIGNALS];
80 static address resettedSighandler[NUM_SIGNALS];
81
82 static void save_signal(int idx, int sig)
83 {
84 struct sigaction sa;
85 sigaction(sig, NULL, &sa);
86 resettedSigflags[idx] = sa.sa_flags;
87 resettedSighandler[idx] = (sa.sa_flags & SA_SIGINFO)
88 ? CAST_FROM_FN_PTR(address, sa.sa_sigaction)
89 : CAST_FROM_FN_PTR(address, sa.sa_handler);
90 }
91
92 int VMError::get_resetted_sigflags(int sig) {
93 for (int i = 0; i < NUM_SIGNALS; i++) {
94 if (SIGNALS[i] == sig) {
95 return resettedSigflags[i];
96 }
97 }
98 return -1;
99 }
100
101 address VMError::get_resetted_sighandler(int sig) {
102 for (int i = 0; i < NUM_SIGNALS; i++) {
103 if (SIGNALS[i] == sig) {
104 return resettedSighandler[i];
105 }
106 }
107 return NULL;
108 }
109
110 static void crash_handler(int sig, siginfo_t* info, void* ucVoid) {
111 // unmask current signal
112 sigset_t newset;
113 sigemptyset(&newset);
114 sigaddset(&newset, sig);
115 // also unmask other synchronous signals
116 for (int i = 0; i < NUM_SIGNALS; i++) {
117 sigaddset(&newset, SIGNALS[i]);
118 }
119 pthread_sigmask(SIG_UNBLOCK, &newset, NULL);
120
121 VMError err(NULL, sig, NULL, info, ucVoid);
122 err.report_and_die();
123 }
124
125 void VMError::reset_signal_handlers() {
126 // install signal handlers for all synchronous program error signals
127 sigset_t newset;
128 sigemptyset(&newset);
129
130 for (int i = 0; i < NUM_SIGNALS; i++) {
131 save_signal(i, SIGNALS[i]);
132 os::signal(SIGNALS[i], CAST_FROM_FN_PTR(void *, crash_handler));
133 sigaddset(&newset, SIGNALS[i]);
134 }
135 pthread_sigmask(SIG_UNBLOCK, &newset, NULL);
136 }
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