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-internals.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-internals.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__) || defined(HOST_WATCHOS)
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)
92 #ifndef PLATFORM_MACOSX
94 mono_runtime_install_handlers (void)
100 mono_runtime_posix_install_handlers(void)
106 mono_runtime_shutdown_handlers (void)
111 mono_runtime_cleanup_handlers (void)
115 #if !defined(PLATFORM_MACOSX)
117 mono_runtime_syscall_fork (void)
119 g_assert_not_reached();
124 mono_gdb_render_native_backtraces (pid_t crashed_pid)
131 static GHashTable *mono_saved_signal_handlers = NULL;
133 static struct sigaction *
134 get_saved_signal_handler (int signo)
136 if (mono_saved_signal_handlers)
137 /* The hash is only modified during startup, so no need for locking */
138 return (struct sigaction *)g_hash_table_lookup (mono_saved_signal_handlers, GINT_TO_POINTER (signo));
143 save_old_signal_handler (int signo, struct sigaction *old_action)
145 struct sigaction *handler_to_save = (struct sigaction *)g_malloc (sizeof (struct sigaction));
147 mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
148 "Saving old signal handler for signal %d.", signo);
150 if (! (old_action->sa_flags & SA_SIGINFO)) {
151 handler_to_save->sa_handler = old_action->sa_handler;
153 #ifdef MONO_ARCH_USE_SIGACTION
154 handler_to_save->sa_sigaction = old_action->sa_sigaction;
155 #endif /* MONO_ARCH_USE_SIGACTION */
157 handler_to_save->sa_mask = old_action->sa_mask;
158 handler_to_save->sa_flags = old_action->sa_flags;
160 if (!mono_saved_signal_handlers)
161 mono_saved_signal_handlers = g_hash_table_new (NULL, NULL);
162 g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
166 free_saved_sig_handler_func (gpointer key, gpointer value, gpointer user_data)
172 free_saved_signal_handlers (void)
174 if (mono_saved_signal_handlers) {
175 g_hash_table_foreach (mono_saved_signal_handlers, free_saved_sig_handler_func, NULL);
176 g_hash_table_destroy (mono_saved_signal_handlers);
177 mono_saved_signal_handlers = NULL;
184 * Call the original signal handler for the signal given by the arguments, which
185 * should be the same as for a signal handler. Returns TRUE if the original handler
186 * was called, false otherwise.
189 MONO_SIG_HANDLER_SIGNATURE (mono_chain_signal)
191 int signal = MONO_SIG_HANDLER_GET_SIGNO ();
192 struct sigaction *saved_handler = (struct sigaction *)get_saved_signal_handler (signal);
194 if (saved_handler && saved_handler->sa_handler) {
195 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
196 saved_handler->sa_handler (signal);
198 #ifdef MONO_ARCH_USE_SIGACTION
199 saved_handler->sa_sigaction (MONO_SIG_HANDLER_PARAMS);
200 #endif /* MONO_ARCH_USE_SIGACTION */
207 MONO_SIG_HANDLER_FUNC (static, sigabrt_signal_handler)
209 MonoJitInfo *ji = NULL;
210 MONO_SIG_HANDLER_INFO_TYPE *info = MONO_SIG_HANDLER_GET_INFO ();
211 MONO_SIG_HANDLER_GET_CONTEXT;
213 if (mono_thread_internal_current ())
214 ji = mono_jit_info_table_find_internal (mono_domain_get (), (char *)mono_arch_ip_from_context (ctx), TRUE, TRUE);
216 if (mono_chain_signal (MONO_SIG_HANDLER_PARAMS))
218 mono_handle_native_sigsegv (SIGABRT, ctx, info);
222 #if defined(__i386__) || defined(__x86_64__)
223 #define FULL_STAT_PROFILER_BACKTRACE 1
224 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
225 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
226 #if MONO_ARCH_STACK_GROWS_UP
227 #define IS_BEFORE_ON_STACK <
228 #define IS_AFTER_ON_STACK >
230 #define IS_BEFORE_ON_STACK >
231 #define IS_AFTER_ON_STACK <
234 #define FULL_STAT_PROFILER_BACKTRACE 0
239 static int profiling_signal_in_use;
241 #if defined(__ia64__) || defined(__sparc__) || defined(sparc)
243 MONO_SIG_HANDLER_FUNC (static, sigprof_signal_handler)
245 if (mono_chain_signal (MONO_SIG_HANDLER_PARAMS))
254 per_thread_profiler_hit (void *ctx)
256 int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
257 MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
259 if (call_chain_depth == 0) {
260 mono_profiler_stat_hit ((guchar *)mono_arch_ip_from_context (ctx), ctx);
262 MonoJitTlsData *jit_tls = (MonoJitTlsData *)mono_native_tls_get_value (mono_jit_tls_id);
263 int current_frame_index = 1;
264 MonoContext mono_context;
265 guchar *ips [call_chain_depth + 1];
267 mono_sigctx_to_monoctx (ctx, &mono_context);
268 ips [0] = (guchar *)MONO_CONTEXT_GET_IP (&mono_context);
270 if (jit_tls != NULL) {
271 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
272 #if FULL_STAT_PROFILER_BACKTRACE
273 guchar *current_frame;
274 guchar *stack_bottom;
277 stack_bottom = (guchar *)jit_tls->end_of_stack;
278 stack_top = (guchar *)MONO_CONTEXT_GET_SP (&mono_context);
279 current_frame = (guchar *)MONO_CONTEXT_GET_BP (&mono_context);
281 while ((current_frame_index <= call_chain_depth) &&
282 (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
283 ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
284 ips [current_frame_index] = (guchar *)CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
285 current_frame_index ++;
286 stack_top = current_frame;
287 current_frame = (guchar *)CURRENT_FRAME_GET_BASE_POINTER (current_frame);
290 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
294 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
295 #if GLIBC_PROFILER_BACKTRACE
296 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
298 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
302 if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
303 MonoDomain *domain = mono_domain_get ();
304 if (domain != NULL) {
308 MonoContext new_mono_context;
310 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
311 &new_mono_context, NULL, &lmf, &native_offset, NULL);
312 while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
313 ips [current_frame_index] = (guchar *)MONO_CONTEXT_GET_IP (&new_mono_context);
314 current_frame_index ++;
315 mono_context = new_mono_context;
316 ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
317 &new_mono_context, NULL, &lmf, &native_offset, NULL);
323 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
327 MONO_SIG_HANDLER_FUNC (static, sigprof_signal_handler)
329 MonoThreadInfo *info;
330 int old_errno = errno;
332 MONO_SIG_HANDLER_GET_CONTEXT;
334 if (mono_thread_info_get_small_id () == -1)
335 return; //an non-attached thread got the signal
337 if (!mono_domain_get () || !mono_native_tls_get_value (mono_jit_tls_id))
338 return; //thread in the process of dettaching
340 hp_save_index = mono_hazard_pointer_save_for_signal_handler ();
342 /* If we can't consume a profiling request it means we're the initiator. */
343 if (!(mono_threads_consume_async_jobs () & MONO_SERVICE_REQUEST_SAMPLE)) {
344 FOREACH_THREAD_SAFE (info) {
345 if (mono_thread_info_get_tid (info) == mono_native_thread_id_get ())
348 mono_threads_add_async_job (info, MONO_SERVICE_REQUEST_SAMPLE);
349 mono_threads_pthread_kill (info, profiling_signal_in_use);
350 } END_FOREACH_THREAD_SAFE;
353 mono_thread_info_set_is_async_context (TRUE);
354 per_thread_profiler_hit (ctx);
355 mono_thread_info_set_is_async_context (FALSE);
357 mono_hazard_pointer_restore_for_signal_handler (hp_save_index);
360 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
366 MONO_SIG_HANDLER_FUNC (static, sigquit_signal_handler)
370 /* We use this signal to start the attach agent too */
371 res = mono_attach_start ();
375 mono_threads_request_thread_dump ();
377 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
380 MONO_SIG_HANDLER_FUNC (static, sigusr2_signal_handler)
382 gboolean enabled = mono_trace_is_enabled ();
384 mono_trace_enable (!enabled);
386 mono_chain_signal (MONO_SIG_HANDLER_PARAMS);
390 add_signal_handler (int signo, gpointer handler)
393 struct sigaction previous_sa;
395 #ifdef MONO_ARCH_USE_SIGACTION
396 sa.sa_sigaction = (void (*)(int, siginfo_t *, void *))handler;
397 sigemptyset (&sa.sa_mask);
398 sa.sa_flags = SA_SIGINFO;
399 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
401 /*Apple likes to deliver SIGBUS for *0 */
402 #ifdef PLATFORM_MACOSX
403 if (signo == SIGSEGV || signo == SIGBUS) {
405 if (signo == SIGSEGV) {
407 sa.sa_flags |= SA_ONSTACK;
410 * libgc will crash when trying to do stack marking for threads which are on
411 * an altstack, so delay the suspend signal after the signal handler has
414 if (mono_gc_get_suspend_signal () != -1)
415 sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
418 if (signo == SIGSEGV) {
420 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
424 sigemptyset (&block_mask);
427 sa.sa_handler = handler;
428 sigemptyset (&sa.sa_mask);
431 g_assert (sigaction (signo, &sa, &previous_sa) != -1);
433 /* if there was already a handler in place for this signal, store it */
434 if (! (previous_sa.sa_flags & SA_SIGINFO) &&
435 (SIG_DFL == previous_sa.sa_handler)) {
436 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
438 if (mono_do_signal_chaining)
439 save_old_signal_handler (signo, &previous_sa);
444 remove_signal_handler (int signo)
447 struct sigaction *saved_action = get_saved_signal_handler (signo);
450 sa.sa_handler = SIG_DFL;
451 sigemptyset (&sa.sa_mask);
454 sigaction (signo, &sa, NULL);
456 g_assert (sigaction (signo, saved_action, NULL) != -1);
461 mono_runtime_posix_install_handlers (void)
466 if (mini_get_debug_options ()->handle_sigint)
467 add_signal_handler (SIGINT, mono_sigint_signal_handler);
469 add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
470 add_signal_handler (SIGQUIT, sigquit_signal_handler);
471 add_signal_handler (SIGILL, mono_sigill_signal_handler);
472 add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
473 if (mono_jit_trace_calls != NULL)
474 add_signal_handler (SIGUSR2, sigusr2_signal_handler);
476 /* it seems to have become a common bug for some programs that run as parents
477 * of many processes to block signal delivery for real time signals.
478 * We try to detect and work around their breakage here.
480 sigemptyset (&signal_set);
481 if (mono_gc_get_suspend_signal () != -1)
482 sigaddset (&signal_set, mono_gc_get_suspend_signal ());
483 if (mono_gc_get_restart_signal () != -1)
484 sigaddset (&signal_set, mono_gc_get_restart_signal ());
485 sigaddset (&signal_set, SIGCHLD);
486 sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
488 signal (SIGPIPE, SIG_IGN);
490 add_signal_handler (SIGABRT, sigabrt_signal_handler);
493 add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
496 #ifndef PLATFORM_MACOSX
498 mono_runtime_install_handlers (void)
500 mono_runtime_posix_install_handlers ();
505 mono_runtime_cleanup_handlers (void)
507 if (mini_get_debug_options ()->handle_sigint)
508 remove_signal_handler (SIGINT);
510 remove_signal_handler (SIGFPE);
511 remove_signal_handler (SIGQUIT);
512 remove_signal_handler (SIGILL);
513 remove_signal_handler (SIGBUS);
514 if (mono_jit_trace_calls != NULL)
515 remove_signal_handler (SIGUSR2);
517 remove_signal_handler (SIGABRT);
519 remove_signal_handler (SIGSEGV);
521 free_saved_signal_handlers ();
524 #ifdef HAVE_LINUX_RTC_H
525 #include <linux/rtc.h>
526 #include <sys/ioctl.h>
528 static int rtc_fd = -1;
531 enable_rtc_timer (gboolean enable)
534 flags = fcntl (rtc_fd, F_GETFL);
543 if (fcntl (rtc_fd, F_SETFL, flags) == -1) {
552 mono_runtime_shutdown_stat_profiler (void)
554 #ifdef HAVE_LINUX_RTC_H
556 enable_rtc_timer (FALSE);
562 get_itimer_mode (void)
564 switch (mono_profiler_get_sampling_mode ()) {
565 case MONO_PROFILER_STAT_MODE_PROCESS: return ITIMER_PROF;
566 case MONO_PROFILER_STAT_MODE_REAL: return ITIMER_REAL;
568 g_assert_not_reached ();
573 get_itimer_signal (void)
575 switch (mono_profiler_get_sampling_mode ()) {
576 case MONO_PROFILER_STAT_MODE_PROCESS: return SIGPROF;
577 case MONO_PROFILER_STAT_MODE_REAL: return SIGALRM;
579 g_assert_not_reached ();
585 mono_runtime_setup_stat_profiler (void)
588 struct itimerval itval;
589 static int inited = 0;
590 #ifdef HAVE_LINUX_RTC_H
591 const char *rtc_freq;
592 if (!inited && (rtc_freq = g_getenv ("MONO_RTC"))) {
596 freq = atoi (rtc_freq);
599 rtc_fd = open ("/dev/rtc", O_RDONLY);
601 perror ("open /dev/rtc");
604 profiling_signal_in_use = SIGPROF;
605 add_signal_handler (profiling_signal_in_use, sigprof_signal_handler);
606 if (ioctl (rtc_fd, RTC_IRQP_SET, freq) == -1) {
607 perror ("set rtc freq");
610 if (ioctl (rtc_fd, RTC_PIE_ON, 0) == -1) {
611 perror ("start rtc");
614 if (fcntl (rtc_fd, F_SETSIG, SIGPROF) == -1) {
618 if (fcntl (rtc_fd, F_SETOWN, getpid ()) == -1) {
622 enable_rtc_timer (TRUE);
629 itval.it_interval.tv_usec = (1000000 / mono_profiler_get_sampling_rate ()) - 1;
630 itval.it_interval.tv_sec = 0;
631 itval.it_value = itval.it_interval;
635 profiling_signal_in_use = get_itimer_signal ();
636 add_signal_handler (profiling_signal_in_use, sigprof_signal_handler);
637 setitimer (get_itimer_mode (), &itval, NULL);
641 #if !defined(PLATFORM_MACOSX)
643 mono_runtime_syscall_fork ()
645 #if defined(PLATFORM_ANDROID)
646 /* SYS_fork is defined to be __NR_fork which is not defined in some ndk versions */
647 g_assert_not_reached ();
649 #elif defined(SYS_fork)
650 return (pid_t) syscall (SYS_fork);
652 g_assert_not_reached ();
658 mono_gdb_render_native_backtraces (pid_t crashed_pid)
660 const char *argv [9];
661 char template_ [] = "/tmp/mono-lldb-commands.XXXXXX";
664 gboolean using_lldb = FALSE;
666 argv [0] = g_find_program_in_path ("gdb");
667 if (argv [0] == NULL) {
668 argv [0] = g_find_program_in_path ("lldb");
672 if (argv [0] == NULL)
676 if (mkstemp (template_) == -1)
679 commands = fopen (template_, "w");
681 fprintf (commands, "process attach --pid %ld\n", (long) crashed_pid);
682 fprintf (commands, "thread list\n");
683 fprintf (commands, "thread backtrace all\n");
684 fprintf (commands, "detach\n");
685 fprintf (commands, "quit\n");
690 argv [1] = "--source";
691 argv [2] = template_;
695 sprintf (buf1, "attach %ld", (long) crashed_pid);
698 argv [4] = "info threads";
700 argv [6] = "thread apply all bt";
701 argv [7] = "--batch";
705 execv (argv [0], (char**)argv);
711 #endif /* __native_client__ */
713 #if !defined (__MACH__)
716 mono_thread_state_init_from_handle (MonoThreadUnwindState *tctx, MonoThreadInfo *info)
718 g_error ("Posix systems don't support mono_thread_state_init_from_handle");