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>
63 #include "debugger-agent.h"
65 #include "jit-icalls.h"
67 #if defined(__native_client__)
70 mono_runtime_setup_stat_profiler (void)
72 printf("WARNING: mono_runtime_setup_stat_profiler() called!\n");
77 mono_runtime_shutdown_stat_profiler (void)
83 SIG_HANDLER_SIGNATURE (mono_chain_signal)
89 mono_runtime_install_handlers (void)
94 mono_runtime_shutdown_handlers (void)
99 mono_runtime_cleanup_handlers (void)
107 static GHashTable *mono_saved_signal_handlers = NULL;
110 get_saved_signal_handler (int signo)
112 if (mono_saved_signal_handlers)
113 /* The hash is only modified during startup, so no need for locking */
114 return g_hash_table_lookup (mono_saved_signal_handlers, GINT_TO_POINTER (signo));
119 save_old_signal_handler (int signo, struct sigaction *old_action)
121 struct sigaction *handler_to_save = g_malloc (sizeof (struct sigaction));
123 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
124 "Saving old signal handler for signal %d.", signo);
126 if (! (old_action->sa_flags & SA_SIGINFO)) {
127 handler_to_save->sa_handler = old_action->sa_handler;
129 #ifdef MONO_ARCH_USE_SIGACTION
130 handler_to_save->sa_sigaction = old_action->sa_sigaction;
131 #endif /* MONO_ARCH_USE_SIGACTION */
133 handler_to_save->sa_mask = old_action->sa_mask;
134 handler_to_save->sa_flags = old_action->sa_flags;
136 if (!mono_saved_signal_handlers)
137 mono_saved_signal_handlers = g_hash_table_new (NULL, NULL);
138 g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
142 free_saved_sig_handler_func (gpointer key, gpointer value, gpointer user_data)
148 free_saved_signal_handlers (void)
150 if (mono_saved_signal_handlers) {
151 g_hash_table_foreach (mono_saved_signal_handlers, free_saved_sig_handler_func, NULL);
152 g_hash_table_destroy (mono_saved_signal_handlers);
153 mono_saved_signal_handlers = NULL;
160 * Call the original signal handler for the signal given by the arguments, which
161 * should be the same as for a signal handler. Returns TRUE if the original handler
162 * was called, false otherwise.
165 SIG_HANDLER_SIGNATURE (mono_chain_signal)
168 struct sigaction *saved_handler = get_saved_signal_handler (signal);
172 if (saved_handler && saved_handler->sa_handler) {
173 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
174 saved_handler->sa_handler (signal);
176 #ifdef MONO_ARCH_USE_SIGACTION
177 saved_handler->sa_sigaction (signal, info, ctx);
178 #endif /* MONO_ARCH_USE_SIGACTION */
186 SIG_HANDLER_SIGNATURE (sigabrt_signal_handler)
188 MonoJitInfo *ji = NULL;
191 if (mono_thread_internal_current ())
192 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx));
194 if (mono_chain_signal (SIG_HANDLER_PARAMS))
196 mono_handle_native_sigsegv (SIGABRT, ctx);
201 SIG_HANDLER_SIGNATURE (sigusr1_signal_handler)
203 gboolean running_managed;
205 MonoInternalThread *thread = mono_thread_internal_current ();
206 MonoDomain *domain = mono_domain_get ();
211 if (!thread || !domain)
212 /* The thread might not have started up yet */
213 /* FIXME: Specify the synchronization with start_wrapper () in threads.c */
216 if (thread->thread_dump_requested) {
217 thread->thread_dump_requested = FALSE;
219 mono_print_thread_dump (ctx);
223 * This is an async signal, so the code below must not call anything which
224 * is not async safe. That includes the pthread locking functions. If we
225 * know that we interrupted managed code, then locking is safe.
228 * On OpenBSD, ctx can be NULL if we are interrupting poll ().
231 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx));
232 running_managed = ji != NULL;
234 if (mono_debugger_agent_thread_interrupt (ctx, ji))
237 running_managed = FALSE;
240 /* We can't do handler block checking from metadata since it requires doing
241 * a stack walk with context.
243 * FIXME add full-aot support.
245 #ifdef MONO_ARCH_HAVE_SIGCTX_TO_MONOCTX
246 if (!mono_aot_only && ctx) {
247 MonoThreadUnwindState unwind_state;
248 if (mono_thread_state_init_from_sigctx (&unwind_state, ctx)) {
249 if (mono_install_handler_block_guard (&unwind_state)) {
251 /*Clear current thread from been wapi interrupted otherwise things can go south*/
252 wapi_clear_interruption ();
260 exc = mono_thread_request_interruption (running_managed);
264 mono_arch_handle_exception (ctx, exc);
267 #if defined(__i386__) || defined(__x86_64__)
268 #define FULL_STAT_PROFILER_BACKTRACE 1
269 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
270 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
271 #if MONO_ARCH_STACK_GROWS_UP
272 #define IS_BEFORE_ON_STACK <
273 #define IS_AFTER_ON_STACK >
275 #define IS_BEFORE_ON_STACK >
276 #define IS_AFTER_ON_STACK <
279 #define FULL_STAT_PROFILER_BACKTRACE 0
282 #if defined(__ia64__) || defined(__sparc__) || defined(sparc) || defined(__s390__) || defined(s390)
285 SIG_HANDLER_SIGNATURE (sigprof_signal_handler)
287 if (mono_chain_signal (SIG_HANDLER_PARAMS))
296 SIG_HANDLER_SIGNATURE (sigprof_signal_handler)
298 int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
299 MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
302 if (call_chain_depth == 0) {
303 mono_profiler_stat_hit (mono_arch_ip_from_context (ctx), ctx);
305 MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
306 int current_frame_index = 1;
307 MonoContext mono_context;
308 guchar *ips [call_chain_depth + 1];
310 mono_arch_sigctx_to_monoctx (ctx, &mono_context);
311 ips [0] = MONO_CONTEXT_GET_IP (&mono_context);
313 if (jit_tls != NULL) {
314 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
315 #if FULL_STAT_PROFILER_BACKTRACE
316 guchar *current_frame;
317 guchar *stack_bottom;
320 stack_bottom = jit_tls->end_of_stack;
321 stack_top = MONO_CONTEXT_GET_SP (&mono_context);
322 current_frame = MONO_CONTEXT_GET_BP (&mono_context);
324 while ((current_frame_index <= call_chain_depth) &&
325 (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
326 ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
327 ips [current_frame_index] = CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
328 current_frame_index ++;
329 stack_top = current_frame;
330 current_frame = CURRENT_FRAME_GET_BASE_POINTER (current_frame);
333 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
337 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
338 #if GLIBC_PROFILER_BACKTRACE
339 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
341 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
345 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
346 MonoDomain *domain = mono_domain_get ();
347 if (domain != NULL) {
351 MonoContext new_mono_context;
353 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
354 &new_mono_context, NULL, &lmf, &native_offset, NULL);
355 while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
356 ips [current_frame_index] = MONO_CONTEXT_GET_IP (&new_mono_context);
357 current_frame_index ++;
358 mono_context = new_mono_context;
359 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
360 &new_mono_context, NULL, &lmf, &native_offset, NULL);
366 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
369 mono_chain_signal (SIG_HANDLER_PARAMS);
375 SIG_HANDLER_SIGNATURE (sigquit_signal_handler)
381 /* We use this signal to start the attach agent too */
382 res = mono_attach_start ();
386 if (mono_thread_info_new_interrupt_enabled ()) {
387 mono_threads_request_thread_dump ();
389 printf ("Full thread dump:\n");
391 mono_threads_request_thread_dump ();
394 * print_thread_dump () skips the current thread, since sending a signal
395 * to it would invoke the signal handler below the sigquit signal handler,
396 * and signal handlers don't create an lmf, so the stack walk could not
399 mono_print_thread_dump (ctx);
402 mono_chain_signal (SIG_HANDLER_PARAMS);
406 SIG_HANDLER_SIGNATURE (sigusr2_signal_handler)
408 gboolean enabled = mono_trace_is_enabled ();
410 mono_trace_enable (!enabled);
412 mono_chain_signal (SIG_HANDLER_PARAMS);
416 add_signal_handler (int signo, gpointer handler)
419 struct sigaction previous_sa;
421 #ifdef MONO_ARCH_USE_SIGACTION
422 sa.sa_sigaction = handler;
423 sigemptyset (&sa.sa_mask);
424 sa.sa_flags = SA_SIGINFO;
425 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
427 /*Apple likes to deliver SIGBUS for *0 */
429 if (signo == SIGSEGV || signo == SIGBUS) {
431 if (signo == SIGSEGV) {
433 sa.sa_flags |= SA_ONSTACK;
436 * libgc will crash when trying to do stack marking for threads which are on
437 * an altstack, so delay the suspend signal after the signal handler has
440 if (mono_gc_get_suspend_signal () != -1)
441 sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
444 if (signo == SIGSEGV) {
446 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
450 sigemptyset (&block_mask);
451 sigaddset (&sa.sa_mask, mono_thread_get_abort_signal ());
454 sa.sa_handler = handler;
455 sigemptyset (&sa.sa_mask);
458 g_assert (sigaction (signo, &sa, &previous_sa) != -1);
460 /* if there was already a handler in place for this signal, store it */
461 if (! (previous_sa.sa_flags & SA_SIGINFO) &&
462 (SIG_DFL == previous_sa.sa_handler)) {
463 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
465 if (mono_do_signal_chaining)
466 save_old_signal_handler (signo, &previous_sa);
471 remove_signal_handler (int signo)
474 struct sigaction *saved_action = get_saved_signal_handler (signo);
477 sa.sa_handler = SIG_DFL;
478 sigemptyset (&sa.sa_mask);
481 sigaction (signo, &sa, NULL);
483 g_assert (sigaction (signo, saved_action, NULL) != -1);
488 mono_runtime_posix_install_handlers (void)
493 if (mini_get_debug_options ()->handle_sigint)
494 add_signal_handler (SIGINT, mono_sigint_signal_handler);
496 add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
497 add_signal_handler (SIGQUIT, sigquit_signal_handler);
498 add_signal_handler (SIGILL, mono_sigill_signal_handler);
499 add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
500 if (mono_jit_trace_calls != NULL)
501 add_signal_handler (SIGUSR2, sigusr2_signal_handler);
503 if (!mono_thread_info_new_interrupt_enabled ())
504 add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler);
505 /* it seems to have become a common bug for some programs that run as parents
506 * of many processes to block signal delivery for real time signals.
507 * We try to detect and work around their breakage here.
509 sigemptyset (&signal_set);
510 sigaddset (&signal_set, mono_thread_get_abort_signal ());
511 sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
513 signal (SIGPIPE, SIG_IGN);
515 add_signal_handler (SIGABRT, sigabrt_signal_handler);
518 add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
521 #ifndef PLATFORM_MACOSX
523 mono_runtime_install_handlers (void)
525 mono_runtime_posix_install_handlers ();
530 mono_runtime_cleanup_handlers (void)
532 if (mini_get_debug_options ()->handle_sigint)
533 remove_signal_handler (SIGINT);
535 remove_signal_handler (SIGFPE);
536 remove_signal_handler (SIGQUIT);
537 remove_signal_handler (SIGILL);
538 remove_signal_handler (SIGBUS);
539 if (mono_jit_trace_calls != NULL)
540 remove_signal_handler (SIGUSR2);
542 remove_signal_handler (mono_thread_get_abort_signal ());
544 remove_signal_handler (SIGABRT);
546 remove_signal_handler (SIGSEGV);
548 free_saved_signal_handlers ();
551 #ifdef HAVE_LINUX_RTC_H
552 #include <linux/rtc.h>
553 #include <sys/ioctl.h>
555 static int rtc_fd = -1;
558 enable_rtc_timer (gboolean enable)
561 flags = fcntl (rtc_fd, F_GETFL);
570 if (fcntl (rtc_fd, F_SETFL, flags) == -1) {
579 mono_runtime_shutdown_stat_profiler (void)
581 #ifdef HAVE_LINUX_RTC_H
583 enable_rtc_timer (FALSE);
588 mono_runtime_setup_stat_profiler (void)
591 struct itimerval itval;
592 static int inited = 0;
593 #ifdef HAVE_LINUX_RTC_H
594 const char *rtc_freq;
595 if (!inited && (rtc_freq = g_getenv ("MONO_RTC"))) {
599 freq = atoi (rtc_freq);
602 rtc_fd = open ("/dev/rtc", O_RDONLY);
604 perror ("open /dev/rtc");
607 add_signal_handler (SIGPROF, sigprof_signal_handler);
608 if (ioctl (rtc_fd, RTC_IRQP_SET, freq) == -1) {
609 perror ("set rtc freq");
612 if (ioctl (rtc_fd, RTC_PIE_ON, 0) == -1) {
613 perror ("start rtc");
616 if (fcntl (rtc_fd, F_SETSIG, SIGPROF) == -1) {
620 if (fcntl (rtc_fd, F_SETOWN, getpid ()) == -1) {
624 enable_rtc_timer (TRUE);
631 itval.it_interval.tv_usec = 999;
632 itval.it_interval.tv_sec = 0;
633 itval.it_value = itval.it_interval;
634 setitimer (ITIMER_PROF, &itval, NULL);
638 add_signal_handler (SIGPROF, sigprof_signal_handler);
642 #if !defined(__APPLE__)
644 mono_runtime_syscall_fork ()
646 #if defined(SYS_fork)
647 return (pid_t) syscall (SYS_fork);
649 g_assert_not_reached ();
655 mono_gdb_render_native_backtraces (pid_t crashed_pid)
657 const char *argv [9];
660 argv [0] = g_find_program_in_path ("gdb");
661 if (argv [0] == NULL) {
666 sprintf (buf1, "attach %ld", (long) crashed_pid);
669 argv [4] = "info threads";
671 argv [6] = "thread apply all bt";
672 argv [7] = "--batch";
675 execv (argv [0], (char**)argv);
678 #endif /* __native_client__ */
680 #if !defined (__MACH__)
683 mono_thread_state_init_from_handle (MonoThreadUnwindState *tctx, MonoNativeThreadId thread_id, MonoNativeThreadHandle thread_handle)
685 g_error ("Posix systems don't support mono_thread_state_init_from_handle");