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>
31 #include <mono/metadata/assembly.h>
32 #include <mono/metadata/loader.h>
33 #include <mono/metadata/tabledefs.h>
34 #include <mono/metadata/class.h>
35 #include <mono/metadata/object.h>
36 #include <mono/metadata/tokentype.h>
37 #include <mono/metadata/tabledefs.h>
38 #include <mono/metadata/threads.h>
39 #include <mono/metadata/appdomain.h>
40 #include <mono/metadata/debug-helpers.h>
41 #include <mono/io-layer/io-layer.h>
42 #include "mono/metadata/profiler.h"
43 #include <mono/metadata/profiler-private.h>
44 #include <mono/metadata/mono-config.h>
45 #include <mono/metadata/environment.h>
46 #include <mono/metadata/mono-debug.h>
47 #include <mono/metadata/gc-internal.h>
48 #include <mono/metadata/threads-types.h>
49 #include <mono/metadata/verify.h>
50 #include <mono/metadata/verify-internals.h>
51 #include <mono/metadata/mempool-internals.h>
52 #include <mono/metadata/attach.h>
53 #include <mono/utils/mono-math.h>
54 #include <mono/utils/mono-compiler.h>
55 #include <mono/utils/mono-counters.h>
56 #include <mono/utils/mono-logger-internal.h>
57 #include <mono/utils/mono-mmap.h>
58 #include <mono/utils/dtrace.h>
59 #include <mono/utils/mono-signal-handler.h>
60 #include <mono/utils/mono-threads.h>
67 #include "debugger-agent.h"
69 #include "jit-icalls.h"
71 #if defined(__native_client__)
74 mono_runtime_setup_stat_profiler (void)
76 printf("WARNING: mono_runtime_setup_stat_profiler() called!\n");
81 mono_runtime_shutdown_stat_profiler (void)
87 MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
93 mono_runtime_install_handlers (void)
98 mono_runtime_shutdown_handlers (void)
103 mono_runtime_cleanup_handlers (void)
108 mono_runtime_syscall_fork (void)
110 g_assert_not_reached();
115 mono_gdb_render_native_backtraces (pid_t crashed_pid)
121 static GHashTable *mono_saved_signal_handlers = NULL;
124 get_saved_signal_handler (int signo)
126 if (mono_saved_signal_handlers)
127 /* The hash is only modified during startup, so no need for locking */
128 return g_hash_table_lookup (mono_saved_signal_handlers, GINT_TO_POINTER (signo));
133 save_old_signal_handler (int signo, struct sigaction *old_action)
135 struct sigaction *handler_to_save = g_malloc (sizeof (struct sigaction));
137 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
138 "Saving old signal handler for signal %d.", signo);
140 if (! (old_action->sa_flags & SA_SIGINFO)) {
141 handler_to_save->sa_handler = old_action->sa_handler;
143 #ifdef MONO_ARCH_USE_SIGACTION
144 handler_to_save->sa_sigaction = old_action->sa_sigaction;
145 #endif /* MONO_ARCH_USE_SIGACTION */
147 handler_to_save->sa_mask = old_action->sa_mask;
148 handler_to_save->sa_flags = old_action->sa_flags;
150 if (!mono_saved_signal_handlers)
151 mono_saved_signal_handlers = g_hash_table_new (NULL, NULL);
152 g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
156 free_saved_sig_handler_func (gpointer key, gpointer value, gpointer user_data)
162 free_saved_signal_handlers (void)
164 if (mono_saved_signal_handlers) {
165 g_hash_table_foreach (mono_saved_signal_handlers, free_saved_sig_handler_func, NULL);
166 g_hash_table_destroy (mono_saved_signal_handlers);
167 mono_saved_signal_handlers = NULL;
174 * Call the original signal handler for the signal given by the arguments, which
175 * should be the same as for a signal handler. Returns TRUE if the original handler
176 * was called, false otherwise.
179 MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
181 int signal = MONO_SIG_HANDLER_GET_SIGNO ();
182 struct sigaction *saved_handler = get_saved_signal_handler (signal);
184 if (saved_handler && saved_handler->sa_handler) {
185 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
186 saved_handler->sa_handler (signal);
188 #ifdef MONO_ARCH_USE_SIGACTION
189 saved_handler->sa_sigaction (MONO_SIG_HANDLER_PARAMS);
190 #endif /* MONO_ARCH_USE_SIGACTION */
197 MONO_SIG_HANDLER_FUNC (static, sigabrt_signal_handler)
199 MonoJitInfo *ji = NULL;
200 MONO_SIG_HANDLER_GET_CONTEXT;
202 if (mono_thread_internal_current ())
203 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context (ctx));
205 if (mono_chain_signal (MONO_SIG_HANDLER_PARAMS))
207 mono_handle_native_sigsegv (SIGABRT, ctx);
211 MONO_SIG_HANDLER_FUNC (static, sigusr1_signal_handler)
213 gboolean running_managed;
215 MonoInternalThread *thread = mono_thread_internal_current ();
216 MonoDomain *domain = mono_domain_get ();
218 MONO_SIG_HANDLER_GET_CONTEXT;
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
300 #if defined(__ia64__) || defined(__sparc__) || defined(sparc) || defined(__s390__) || defined(s390)
302 MONO_SIG_HANDLER_FUNC (static, sigprof_signal_handler)
304 if (mono_chain_signal (MONO_SIG_HANDLER_PARAMS))
313 get_stage2_signal_handler (void)
315 #if defined(PLATFORM_ANDROID)
317 #elif !defined (SIGRTMIN)
324 static int prof2_signum = -1;
326 if (prof2_signum != -1)
328 /* we try to avoid SIGRTMIN and any one that might have been set already */
329 for (i = SIGRTMIN + 2; i < SIGRTMAX; ++i) {
330 struct sigaction sinfo;
331 sigaction (i, NULL, &sinfo);
332 if (sinfo.sa_handler == SIG_DFL && (void*)sinfo.sa_sigaction == (void*)SIG_DFL) {
337 /* fallback to the old way */
344 per_thread_profiler_hit (void *ctx)
346 int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
347 MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
349 if (call_chain_depth == 0) {
350 mono_profiler_stat_hit (mono_arch_ip_from_context (ctx), ctx);
352 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
353 int current_frame_index = 1;
354 MonoContext mono_context;
355 guchar *ips [call_chain_depth + 1];
357 mono_arch_sigctx_to_monoctx (ctx, &mono_context);
358 ips [0] = MONO_CONTEXT_GET_IP (&mono_context);
360 if (jit_tls != NULL) {
361 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
362 #if FULL_STAT_PROFILER_BACKTRACE
363 guchar *current_frame;
364 guchar *stack_bottom;
367 stack_bottom = jit_tls->end_of_stack;
368 stack_top = MONO_CONTEXT_GET_SP (&mono_context);
369 current_frame = MONO_CONTEXT_GET_BP (&mono_context);
371 while ((current_frame_index <= call_chain_depth) &&
372 (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
373 ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
374 ips [current_frame_index] = CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
375 current_frame_index ++;
376 stack_top = current_frame;
377 current_frame = CURRENT_FRAME_GET_BASE_POINTER (current_frame);
380 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
384 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
385 #if GLIBC_PROFILER_BACKTRACE
386 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
388 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
392 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
393 MonoDomain *domain = mono_domain_get ();
394 if (domain != NULL) {
398 MonoContext new_mono_context;
400 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
401 &new_mono_context, NULL, &lmf, &native_offset, NULL);
402 while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
403 ips [current_frame_index] = MONO_CONTEXT_GET_IP (&new_mono_context);
404 current_frame_index ++;
405 mono_context = new_mono_context;
406 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
407 &new_mono_context, NULL, &lmf, &native_offset, NULL);
413 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
417 MONO_SIG_HANDLER_FUNC (static, sigprof_stage2_signal_handler)
419 MONO_SIG_HANDLER_GET_CONTEXT;
421 per_thread_profiler_hit (ctx);
423 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
426 MONO_SIG_HANDLER_FUNC (static, sigprof_signal_handler)
428 MonoThreadInfo *info;
429 int old_errno = errno;
430 int hp_save_index = mono_hazard_pointer_save_for_signal_handler ();
431 MONO_SIG_HANDLER_GET_CONTEXT;
433 FOREACH_THREAD_SAFE (info) {
434 if (mono_thread_info_get_tid (info) == mono_native_thread_id_get ())
436 mono_threads_pthread_kill (info, get_stage2_signal_handler ());
437 } END_FOREACH_THREAD_SAFE;
439 per_thread_profiler_hit (ctx);
441 mono_hazard_pointer_restore_for_signal_handler (hp_save_index);
444 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
450 MONO_SIG_HANDLER_FUNC (static, sigquit_signal_handler)
453 MONO_SIG_HANDLER_GET_CONTEXT;
455 /* We use this signal to start the attach agent too */
456 res = mono_attach_start ();
460 if (mono_thread_info_new_interrupt_enabled ()) {
461 mono_threads_request_thread_dump ();
463 printf ("Full thread dump:\n");
465 mono_threads_request_thread_dump ();
468 * print_thread_dump () skips the current thread, since sending a signal
469 * to it would invoke the signal handler below the sigquit signal handler,
470 * and signal handlers don't create an lmf, so the stack walk could not
473 mono_print_thread_dump (ctx);
476 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
479 MONO_SIG_HANDLER_FUNC (static, sigusr2_signal_handler)
481 gboolean enabled = mono_trace_is_enabled ();
483 mono_trace_enable (!enabled);
485 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
489 add_signal_handler (int signo, gpointer handler)
492 struct sigaction previous_sa;
494 #ifdef MONO_ARCH_USE_SIGACTION
495 sa.sa_sigaction = handler;
496 sigemptyset (&sa.sa_mask);
497 sa.sa_flags = SA_SIGINFO;
498 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
500 /*Apple likes to deliver SIGBUS for *0 */
502 if (signo == SIGSEGV || signo == SIGBUS) {
504 if (signo == SIGSEGV) {
506 sa.sa_flags |= SA_ONSTACK;
509 * libgc will crash when trying to do stack marking for threads which are on
510 * an altstack, so delay the suspend signal after the signal handler has
513 if (mono_gc_get_suspend_signal () != -1)
514 sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
517 if (signo == SIGSEGV) {
519 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
523 sigemptyset (&block_mask);
524 sigaddset (&sa.sa_mask, mono_thread_get_abort_signal ());
527 sa.sa_handler = handler;
528 sigemptyset (&sa.sa_mask);
531 g_assert (sigaction (signo, &sa, &previous_sa) != -1);
533 /* if there was already a handler in place for this signal, store it */
534 if (! (previous_sa.sa_flags & SA_SIGINFO) &&
535 (SIG_DFL == previous_sa.sa_handler)) {
536 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
538 if (mono_do_signal_chaining)
539 save_old_signal_handler (signo, &previous_sa);
544 remove_signal_handler (int signo)
547 struct sigaction *saved_action = get_saved_signal_handler (signo);
550 sa.sa_handler = SIG_DFL;
551 sigemptyset (&sa.sa_mask);
554 sigaction (signo, &sa, NULL);
556 g_assert (sigaction (signo, saved_action, NULL) != -1);
561 mono_runtime_posix_install_handlers (void)
566 if (mini_get_debug_options ()->handle_sigint)
567 add_signal_handler (SIGINT, mono_sigint_signal_handler);
569 add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
570 add_signal_handler (SIGQUIT, sigquit_signal_handler);
571 add_signal_handler (SIGILL, mono_sigill_signal_handler);
572 add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
573 if (mono_jit_trace_calls != NULL)
574 add_signal_handler (SIGUSR2, sigusr2_signal_handler);
576 if (!mono_thread_info_new_interrupt_enabled ())
577 add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler);
578 /* it seems to have become a common bug for some programs that run as parents
579 * of many processes to block signal delivery for real time signals.
580 * We try to detect and work around their breakage here.
582 sigemptyset (&signal_set);
583 sigaddset (&signal_set, mono_thread_get_abort_signal ());
584 if (mono_gc_get_suspend_signal () != -1)
585 sigaddset (&signal_set, mono_gc_get_suspend_signal ());
586 if (mono_gc_get_restart_signal () != -1)
587 sigaddset (&signal_set, mono_gc_get_restart_signal ());
588 sigaddset (&signal_set, SIGCHLD);
589 sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
591 signal (SIGPIPE, SIG_IGN);
593 add_signal_handler (SIGABRT, sigabrt_signal_handler);
596 add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
599 #ifndef PLATFORM_MACOSX
601 mono_runtime_install_handlers (void)
603 mono_runtime_posix_install_handlers ();
608 mono_runtime_cleanup_handlers (void)
610 if (mini_get_debug_options ()->handle_sigint)
611 remove_signal_handler (SIGINT);
613 remove_signal_handler (SIGFPE);
614 remove_signal_handler (SIGQUIT);
615 remove_signal_handler (SIGILL);
616 remove_signal_handler (SIGBUS);
617 if (mono_jit_trace_calls != NULL)
618 remove_signal_handler (SIGUSR2);
620 remove_signal_handler (mono_thread_get_abort_signal ());
622 remove_signal_handler (SIGABRT);
624 remove_signal_handler (SIGSEGV);
626 free_saved_signal_handlers ();
629 #ifdef HAVE_LINUX_RTC_H
630 #include <linux/rtc.h>
631 #include <sys/ioctl.h>
633 static int rtc_fd = -1;
636 enable_rtc_timer (gboolean enable)
639 flags = fcntl (rtc_fd, F_GETFL);
648 if (fcntl (rtc_fd, F_SETFL, flags) == -1) {
657 mono_runtime_shutdown_stat_profiler (void)
659 #ifdef HAVE_LINUX_RTC_H
661 enable_rtc_timer (FALSE);
667 get_itimer_mode (void)
669 switch (mono_profiler_get_sampling_mode ()) {
670 case MONO_PROFILER_STAT_MODE_PROCESS: return ITIMER_PROF;
671 case MONO_PROFILER_STAT_MODE_REAL: return ITIMER_REAL;
673 g_assert_not_reached ();
678 get_itimer_signal (void)
680 switch (mono_profiler_get_sampling_mode ()) {
681 case MONO_PROFILER_STAT_MODE_PROCESS: return SIGPROF;
682 case MONO_PROFILER_STAT_MODE_REAL: return SIGALRM;
684 g_assert_not_reached ();
690 mono_runtime_setup_stat_profiler (void)
693 struct itimerval itval;
694 static int inited = 0;
695 #ifdef HAVE_LINUX_RTC_H
696 const char *rtc_freq;
697 if (!inited && (rtc_freq = g_getenv ("MONO_RTC"))) {
701 freq = atoi (rtc_freq);
704 rtc_fd = open ("/dev/rtc", O_RDONLY);
706 perror ("open /dev/rtc");
709 add_signal_handler (SIGPROF, sigprof_signal_handler);
710 if (ioctl (rtc_fd, RTC_IRQP_SET, freq) == -1) {
711 perror ("set rtc freq");
714 if (ioctl (rtc_fd, RTC_PIE_ON, 0) == -1) {
715 perror ("start rtc");
718 if (fcntl (rtc_fd, F_SETSIG, SIGPROF) == -1) {
722 if (fcntl (rtc_fd, F_SETOWN, getpid ()) == -1) {
726 enable_rtc_timer (TRUE);
733 itval.it_interval.tv_usec = (1000000 / mono_profiler_get_sampling_rate ()) - 1;
734 itval.it_interval.tv_sec = 0;
735 itval.it_value = itval.it_interval;
739 add_signal_handler (get_itimer_signal (), sigprof_signal_handler);
740 add_signal_handler (get_stage2_signal_handler (), sigprof_stage2_signal_handler);
741 setitimer (get_itimer_mode (), &itval, NULL);
745 #if !defined(__APPLE__)
747 mono_runtime_syscall_fork ()
749 #if defined(SYS_fork)
750 return (pid_t) syscall (SYS_fork);
752 g_assert_not_reached ();
758 mono_gdb_render_native_backtraces (pid_t crashed_pid)
760 const char *argv [9];
761 char template [] = "/tmp/mono-lldb-commands.XXXXXX";
764 gboolean using_lldb = FALSE;
766 argv [0] = g_find_program_in_path ("gdb");
767 if (argv [0] == NULL) {
768 argv [0] = g_find_program_in_path ("lldb");
772 if (argv [0] == NULL)
776 if (mkstemp (template) == -1)
779 commands = fopen (template, "w");
781 fprintf (commands, "process attach --pid %ld\n", (long) crashed_pid);
782 fprintf (commands, "thread list\n");
783 fprintf (commands, "thread backtrace all\n");
784 fprintf (commands, "detach\n");
785 fprintf (commands, "quit\n");
790 argv [1] = "--source";
795 sprintf (buf1, "attach %ld", (long) crashed_pid);
798 argv [4] = "info threads";
800 argv [6] = "thread apply all bt";
801 argv [7] = "--batch";
805 execv (argv [0], (char**)argv);
811 #endif /* __native_client__ */
813 #if !defined (__MACH__)
816 mono_thread_state_init_from_handle (MonoThreadUnwindState *tctx, MonoThreadInfo *info)
818 g_error ("Posix systems don't support mono_thread_state_init_from_handle");