2 * mini-posix.c: POSIX signal handling support for Mono.
5 * Mono Team (mono-list@lists.ximian.com)
7 * Copyright 2001-2003 Ximian, Inc.
8 * Copyright 2003-2008 Ximian, Inc.
9 * Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
11 * See LICENSE for licensing information.
22 #ifdef HAVE_SYS_TIME_H
25 #ifdef HAVE_SYS_SYSCALL_H
26 #include <sys/syscall.h>
29 #include <mono/metadata/assembly.h>
30 #include <mono/metadata/loader.h>
31 #include <mono/metadata/tabledefs.h>
32 #include <mono/metadata/class.h>
33 #include <mono/metadata/object.h>
34 #include <mono/metadata/tokentype.h>
35 #include <mono/metadata/tabledefs.h>
36 #include <mono/metadata/threads.h>
37 #include <mono/metadata/appdomain.h>
38 #include <mono/metadata/debug-helpers.h>
39 #include <mono/io-layer/io-layer.h>
40 #include "mono/metadata/profiler.h"
41 #include <mono/metadata/profiler-private.h>
42 #include <mono/metadata/mono-config.h>
43 #include <mono/metadata/environment.h>
44 #include <mono/metadata/mono-debug.h>
45 #include <mono/metadata/gc-internal.h>
46 #include <mono/metadata/threads-types.h>
47 #include <mono/metadata/verify.h>
48 #include <mono/metadata/verify-internals.h>
49 #include <mono/metadata/mempool-internals.h>
50 #include <mono/metadata/attach.h>
51 #include <mono/utils/mono-math.h>
52 #include <mono/utils/mono-compiler.h>
53 #include <mono/utils/mono-counters.h>
54 #include <mono/utils/mono-logger-internal.h>
55 #include <mono/utils/mono-mmap.h>
56 #include <mono/utils/dtrace.h>
57 #include <mono/utils/mono-signal-handler.h>
64 #include "debugger-agent.h"
66 #include "jit-icalls.h"
68 #if defined(__native_client__)
71 mono_runtime_setup_stat_profiler (void)
73 printf("WARNING: mono_runtime_setup_stat_profiler() called!\n");
78 mono_runtime_shutdown_stat_profiler (void)
84 SIG_HANDLER_SIGNATURE (mono_chain_signal)
90 mono_runtime_install_handlers (void)
95 mono_runtime_shutdown_handlers (void)
100 mono_runtime_cleanup_handlers (void)
105 mono_runtime_syscall_fork (void)
107 g_assert_not_reached();
112 mono_gdb_render_native_backtraces (pid_t crashed_pid)
118 static GHashTable *mono_saved_signal_handlers = NULL;
121 get_saved_signal_handler (int signo)
123 if (mono_saved_signal_handlers)
124 /* The hash is only modified during startup, so no need for locking */
125 return g_hash_table_lookup (mono_saved_signal_handlers, GINT_TO_POINTER (signo));
130 save_old_signal_handler (int signo, struct sigaction *old_action)
132 struct sigaction *handler_to_save = g_malloc (sizeof (struct sigaction));
134 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
135 "Saving old signal handler for signal %d.", signo);
137 if (! (old_action->sa_flags & SA_SIGINFO)) {
138 handler_to_save->sa_handler = old_action->sa_handler;
140 #ifdef MONO_ARCH_USE_SIGACTION
141 handler_to_save->sa_sigaction = old_action->sa_sigaction;
142 #endif /* MONO_ARCH_USE_SIGACTION */
144 handler_to_save->sa_mask = old_action->sa_mask;
145 handler_to_save->sa_flags = old_action->sa_flags;
147 if (!mono_saved_signal_handlers)
148 mono_saved_signal_handlers = g_hash_table_new (NULL, NULL);
149 g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
153 free_saved_sig_handler_func (gpointer key, gpointer value, gpointer user_data)
159 free_saved_signal_handlers (void)
161 if (mono_saved_signal_handlers) {
162 g_hash_table_foreach (mono_saved_signal_handlers, free_saved_sig_handler_func, NULL);
163 g_hash_table_destroy (mono_saved_signal_handlers);
164 mono_saved_signal_handlers = NULL;
171 * Call the original signal handler for the signal given by the arguments, which
172 * should be the same as for a signal handler. Returns TRUE if the original handler
173 * was called, false otherwise.
176 SIG_HANDLER_SIGNATURE (mono_chain_signal)
179 struct sigaction *saved_handler = get_saved_signal_handler (signal);
183 if (saved_handler && saved_handler->sa_handler) {
184 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
185 saved_handler->sa_handler (signal);
187 #ifdef MONO_ARCH_USE_SIGACTION
188 saved_handler->sa_sigaction (signal, info, ctx);
189 #endif /* MONO_ARCH_USE_SIGACTION */
196 SIG_HANDLER_FUNC (static, sigabrt_signal_handler)
198 MonoJitInfo *ji = NULL;
201 if (mono_thread_internal_current ())
202 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx));
204 if (mono_chain_signal (SIG_HANDLER_PARAMS))
206 mono_handle_native_sigsegv (SIGABRT, ctx);
210 SIG_HANDLER_FUNC (static, sigusr1_signal_handler)
212 gboolean running_managed;
214 MonoInternalThread *thread = mono_thread_internal_current ();
215 MonoDomain *domain = mono_domain_get ();
220 if (!thread || !domain) {
221 /* The thread might not have started up yet */
222 /* FIXME: Specify the synchronization with start_wrapper () in threads.c */
223 mono_debugger_agent_thread_interrupt (ctx, NULL);
227 if (thread->ignore_next_signal) {
228 thread->ignore_next_signal = FALSE;
232 if (thread->thread_dump_requested) {
233 thread->thread_dump_requested = FALSE;
235 mono_print_thread_dump (ctx);
239 * This is an async signal, so the code below must not call anything which
240 * is not async safe. That includes the pthread locking functions. If we
241 * know that we interrupted managed code, then locking is safe.
244 * On OpenBSD, ctx can be NULL if we are interrupting poll ().
247 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx));
248 running_managed = ji != NULL;
250 if (mono_debugger_agent_thread_interrupt (ctx, ji))
253 running_managed = FALSE;
256 /* We can't do handler block checking from metadata since it requires doing
257 * a stack walk with context.
259 * FIXME add full-aot support.
261 #ifdef MONO_ARCH_HAVE_SIGCTX_TO_MONOCTX
262 if (!mono_aot_only && ctx) {
263 MonoThreadUnwindState unwind_state;
264 if (mono_thread_state_init_from_sigctx (&unwind_state, ctx)) {
265 if (mono_install_handler_block_guard (&unwind_state)) {
267 /*Clear current thread from been wapi interrupted otherwise things can go south*/
268 wapi_clear_interruption ();
276 exc = mono_thread_request_interruption (running_managed);
280 mono_arch_handle_exception (ctx, exc);
284 #if defined(__i386__) || defined(__x86_64__)
285 #define FULL_STAT_PROFILER_BACKTRACE 1
286 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
287 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
288 #if MONO_ARCH_STACK_GROWS_UP
289 #define IS_BEFORE_ON_STACK <
290 #define IS_AFTER_ON_STACK >
292 #define IS_BEFORE_ON_STACK >
293 #define IS_AFTER_ON_STACK <
296 #define FULL_STAT_PROFILER_BACKTRACE 0
299 #if defined(__ia64__) || defined(__sparc__) || defined(sparc) || defined(__s390__) || defined(s390)
301 SIG_HANDLER_FUNC (static, sigprof_signal_handler)
303 if (mono_chain_signal (SIG_HANDLER_PARAMS))
311 SIG_HANDLER_FUNC (static, sigprof_signal_handler)
313 int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
314 MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
317 if (call_chain_depth == 0) {
318 mono_profiler_stat_hit (mono_arch_ip_from_context (ctx), ctx);
320 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
321 int current_frame_index = 1;
322 MonoContext mono_context;
323 guchar *ips [call_chain_depth + 1];
325 mono_arch_sigctx_to_monoctx (ctx, &mono_context);
326 ips [0] = MONO_CONTEXT_GET_IP (&mono_context);
328 if (jit_tls != NULL) {
329 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
330 #if FULL_STAT_PROFILER_BACKTRACE
331 guchar *current_frame;
332 guchar *stack_bottom;
335 stack_bottom = jit_tls->end_of_stack;
336 stack_top = MONO_CONTEXT_GET_SP (&mono_context);
337 current_frame = MONO_CONTEXT_GET_BP (&mono_context);
339 while ((current_frame_index <= call_chain_depth) &&
340 (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
341 ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
342 ips [current_frame_index] = CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
343 current_frame_index ++;
344 stack_top = current_frame;
345 current_frame = CURRENT_FRAME_GET_BASE_POINTER (current_frame);
348 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
352 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
353 #if GLIBC_PROFILER_BACKTRACE
354 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
356 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
360 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
361 MonoDomain *domain = mono_domain_get ();
362 if (domain != NULL) {
366 MonoContext new_mono_context;
368 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
369 &new_mono_context, NULL, &lmf, &native_offset, NULL);
370 while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
371 ips [current_frame_index] = MONO_CONTEXT_GET_IP (&new_mono_context);
372 current_frame_index ++;
373 mono_context = new_mono_context;
374 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
375 &new_mono_context, NULL, &lmf, &native_offset, NULL);
381 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
384 mono_chain_signal (SIG_HANDLER_PARAMS);
389 SIG_HANDLER_FUNC (static, sigquit_signal_handler)
395 /* We use this signal to start the attach agent too */
396 res = mono_attach_start ();
400 if (mono_thread_info_new_interrupt_enabled ()) {
401 mono_threads_request_thread_dump ();
403 printf ("Full thread dump:\n");
405 mono_threads_request_thread_dump ();
408 * print_thread_dump () skips the current thread, since sending a signal
409 * to it would invoke the signal handler below the sigquit signal handler,
410 * and signal handlers don't create an lmf, so the stack walk could not
413 mono_print_thread_dump (ctx);
416 mono_chain_signal (SIG_HANDLER_PARAMS);
419 SIG_HANDLER_FUNC (static, sigusr2_signal_handler)
421 gboolean enabled = mono_trace_is_enabled ();
423 mono_trace_enable (!enabled);
425 mono_chain_signal (SIG_HANDLER_PARAMS);
429 add_signal_handler (int signo, gpointer handler)
432 struct sigaction previous_sa;
434 #ifdef MONO_ARCH_USE_SIGACTION
435 sa.sa_sigaction = handler;
436 sigemptyset (&sa.sa_mask);
437 sa.sa_flags = SA_SIGINFO;
438 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
440 /*Apple likes to deliver SIGBUS for *0 */
442 if (signo == SIGSEGV || signo == SIGBUS) {
444 if (signo == SIGSEGV) {
446 sa.sa_flags |= SA_ONSTACK;
449 * libgc will crash when trying to do stack marking for threads which are on
450 * an altstack, so delay the suspend signal after the signal handler has
453 if (mono_gc_get_suspend_signal () != -1)
454 sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
457 if (signo == SIGSEGV) {
459 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
463 sigemptyset (&block_mask);
464 sigaddset (&sa.sa_mask, mono_thread_get_abort_signal ());
467 sa.sa_handler = handler;
468 sigemptyset (&sa.sa_mask);
471 g_assert (sigaction (signo, &sa, &previous_sa) != -1);
473 /* if there was already a handler in place for this signal, store it */
474 if (! (previous_sa.sa_flags & SA_SIGINFO) &&
475 (SIG_DFL == previous_sa.sa_handler)) {
476 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
478 if (mono_do_signal_chaining)
479 save_old_signal_handler (signo, &previous_sa);
484 remove_signal_handler (int signo)
487 struct sigaction *saved_action = get_saved_signal_handler (signo);
490 sa.sa_handler = SIG_DFL;
491 sigemptyset (&sa.sa_mask);
494 sigaction (signo, &sa, NULL);
496 g_assert (sigaction (signo, saved_action, NULL) != -1);
501 mono_runtime_posix_install_handlers (void)
506 if (mini_get_debug_options ()->handle_sigint)
507 add_signal_handler (SIGINT, mono_sigint_signal_handler);
509 add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
510 add_signal_handler (SIGQUIT, sigquit_signal_handler);
511 add_signal_handler (SIGILL, mono_sigill_signal_handler);
512 add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
513 if (mono_jit_trace_calls != NULL)
514 add_signal_handler (SIGUSR2, sigusr2_signal_handler);
516 if (!mono_thread_info_new_interrupt_enabled ())
517 add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler);
518 /* it seems to have become a common bug for some programs that run as parents
519 * of many processes to block signal delivery for real time signals.
520 * We try to detect and work around their breakage here.
522 sigemptyset (&signal_set);
523 sigaddset (&signal_set, mono_thread_get_abort_signal ());
524 sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
526 signal (SIGPIPE, SIG_IGN);
528 add_signal_handler (SIGABRT, sigabrt_signal_handler);
531 add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
534 #ifndef PLATFORM_MACOSX
536 mono_runtime_install_handlers (void)
538 mono_runtime_posix_install_handlers ();
543 mono_runtime_cleanup_handlers (void)
545 if (mini_get_debug_options ()->handle_sigint)
546 remove_signal_handler (SIGINT);
548 remove_signal_handler (SIGFPE);
549 remove_signal_handler (SIGQUIT);
550 remove_signal_handler (SIGILL);
551 remove_signal_handler (SIGBUS);
552 if (mono_jit_trace_calls != NULL)
553 remove_signal_handler (SIGUSR2);
555 remove_signal_handler (mono_thread_get_abort_signal ());
557 remove_signal_handler (SIGABRT);
559 remove_signal_handler (SIGSEGV);
561 free_saved_signal_handlers ();
564 #ifdef HAVE_LINUX_RTC_H
565 #include <linux/rtc.h>
566 #include <sys/ioctl.h>
568 static int rtc_fd = -1;
571 enable_rtc_timer (gboolean enable)
574 flags = fcntl (rtc_fd, F_GETFL);
583 if (fcntl (rtc_fd, F_SETFL, flags) == -1) {
592 mono_runtime_shutdown_stat_profiler (void)
594 #ifdef HAVE_LINUX_RTC_H
596 enable_rtc_timer (FALSE);
601 mono_runtime_setup_stat_profiler (void)
604 struct itimerval itval;
605 static int inited = 0;
606 #ifdef HAVE_LINUX_RTC_H
607 const char *rtc_freq;
608 if (!inited && (rtc_freq = g_getenv ("MONO_RTC"))) {
612 freq = atoi (rtc_freq);
615 rtc_fd = open ("/dev/rtc", O_RDONLY);
617 perror ("open /dev/rtc");
620 add_signal_handler (SIGPROF, sigprof_signal_handler);
621 if (ioctl (rtc_fd, RTC_IRQP_SET, freq) == -1) {
622 perror ("set rtc freq");
625 if (ioctl (rtc_fd, RTC_PIE_ON, 0) == -1) {
626 perror ("start rtc");
629 if (fcntl (rtc_fd, F_SETSIG, SIGPROF) == -1) {
633 if (fcntl (rtc_fd, F_SETOWN, getpid ()) == -1) {
637 enable_rtc_timer (TRUE);
644 itval.it_interval.tv_usec = 999;
645 itval.it_interval.tv_sec = 0;
646 itval.it_value = itval.it_interval;
647 setitimer (ITIMER_PROF, &itval, NULL);
651 add_signal_handler (SIGPROF, sigprof_signal_handler);
655 #if !defined(__APPLE__)
657 mono_runtime_syscall_fork ()
659 #if defined(SYS_fork)
660 return (pid_t) syscall (SYS_fork);
662 g_assert_not_reached ();
668 mono_gdb_render_native_backtraces (pid_t crashed_pid)
670 const char *argv [9];
671 char template [] = "/tmp/mono-lldb-commands.XXXXXX";
674 gboolean using_lldb = FALSE;
676 argv [0] = g_find_program_in_path ("gdb");
677 if (argv [0] == NULL) {
678 argv [0] = g_find_program_in_path ("lldb");
682 if (argv [0] == NULL)
686 if (mkstemp (template) == -1)
689 commands = fopen (template, "w");
691 fprintf (commands, "process attach --pid %ld\n", (long) crashed_pid);
692 fprintf (commands, "script lldb.debugger.HandleCommand (\"thread list\")\n");
693 fprintf (commands, "script lldb.debugger.HandleCommand (\"thread backtrace all\")\n");
694 fprintf (commands, "detach\n");
695 fprintf (commands, "quit\n");
700 argv [1] = "--source";
705 sprintf (buf1, "attach %ld", (long) crashed_pid);
708 argv [4] = "info threads";
710 argv [6] = "thread apply all bt";
711 argv [7] = "--batch";
715 execv (argv [0], (char**)argv);
721 #endif /* __native_client__ */
723 #if !defined (__MACH__)
726 mono_thread_state_init_from_handle (MonoThreadUnwindState *tctx, MonoNativeThreadId thread_id, MonoNativeThreadHandle thread_handle)
728 g_error ("Posix systems don't support mono_thread_state_init_from_handle");