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
->ignore_next_signal
) {
217 thread
->ignore_next_signal
= FALSE
;
221 if (thread
->thread_dump_requested
) {
222 thread
->thread_dump_requested
= FALSE
;
224 mono_print_thread_dump (ctx
);
228 * This is an async signal, so the code below must not call anything which
229 * is not async safe. That includes the pthread locking functions. If we
230 * know that we interrupted managed code, then locking is safe.
233 * On OpenBSD, ctx can be NULL if we are interrupting poll ().
236 ji
= mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx
));
237 running_managed
= ji
!= NULL
;
239 if (mono_debugger_agent_thread_interrupt (ctx
, ji
))
242 running_managed
= FALSE
;
245 /* We can't do handler block checking from metadata since it requires doing
246 * a stack walk with context.
248 * FIXME add full-aot support.
250 #ifdef MONO_ARCH_HAVE_SIGCTX_TO_MONOCTX
251 if (!mono_aot_only
&& ctx
) {
252 MonoThreadUnwindState unwind_state
;
253 if (mono_thread_state_init_from_sigctx (&unwind_state
, ctx
)) {
254 if (mono_install_handler_block_guard (&unwind_state
)) {
256 /*Clear current thread from been wapi interrupted otherwise things can go south*/
257 wapi_clear_interruption ();
265 exc
= mono_thread_request_interruption (running_managed
);
269 mono_arch_handle_exception (ctx
, exc
);
272 #if defined(__i386__) || defined(__x86_64__)
273 #define FULL_STAT_PROFILER_BACKTRACE 1
274 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
275 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
276 #if MONO_ARCH_STACK_GROWS_UP
277 #define IS_BEFORE_ON_STACK <
278 #define IS_AFTER_ON_STACK >
280 #define IS_BEFORE_ON_STACK >
281 #define IS_AFTER_ON_STACK <
284 #define FULL_STAT_PROFILER_BACKTRACE 0
287 #if defined(__ia64__) || defined(__sparc__) || defined(sparc) || defined(__s390__) || defined(s390)
290 SIG_HANDLER_SIGNATURE (sigprof_signal_handler
)
292 if (mono_chain_signal (SIG_HANDLER_PARAMS
))
301 SIG_HANDLER_SIGNATURE (sigprof_signal_handler
)
303 int call_chain_depth
= mono_profiler_stat_get_call_chain_depth ();
304 MonoProfilerCallChainStrategy call_chain_strategy
= mono_profiler_stat_get_call_chain_strategy ();
307 if (call_chain_depth
== 0) {
308 mono_profiler_stat_hit (mono_arch_ip_from_context (ctx
), ctx
);
310 MonoJitTlsData
*jit_tls
= mono_native_tls_get_value (mono_jit_tls_id
);
311 int current_frame_index
= 1;
312 MonoContext mono_context
;
313 guchar
*ips
[call_chain_depth
+ 1];
315 mono_arch_sigctx_to_monoctx (ctx
, &mono_context
);
316 ips
[0] = MONO_CONTEXT_GET_IP (&mono_context
);
318 if (jit_tls
!= NULL
) {
319 if (call_chain_strategy
== MONO_PROFILER_CALL_CHAIN_NATIVE
) {
320 #if FULL_STAT_PROFILER_BACKTRACE
321 guchar
*current_frame
;
322 guchar
*stack_bottom
;
325 stack_bottom
= jit_tls
->end_of_stack
;
326 stack_top
= MONO_CONTEXT_GET_SP (&mono_context
);
327 current_frame
= MONO_CONTEXT_GET_BP (&mono_context
);
329 while ((current_frame_index
<= call_chain_depth
) &&
330 (stack_bottom
IS_BEFORE_ON_STACK (guchar
*) current_frame
) &&
331 ((guchar
*) current_frame IS_BEFORE_ON_STACK stack_top
)) {
332 ips
[current_frame_index
] = CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame
);
333 current_frame_index
++;
334 stack_top
= current_frame
;
335 current_frame
= CURRENT_FRAME_GET_BASE_POINTER (current_frame
);
338 call_chain_strategy
= MONO_PROFILER_CALL_CHAIN_GLIBC
;
342 if (call_chain_strategy
== MONO_PROFILER_CALL_CHAIN_GLIBC
) {
343 #if GLIBC_PROFILER_BACKTRACE
344 current_frame_index
= backtrace ((void**) & ips
[1], call_chain_depth
);
346 call_chain_strategy
= MONO_PROFILER_CALL_CHAIN_MANAGED
;
350 if (call_chain_strategy
== MONO_PROFILER_CALL_CHAIN_MANAGED
) {
351 MonoDomain
*domain
= mono_domain_get ();
352 if (domain
!= NULL
) {
356 MonoContext new_mono_context
;
358 ji
= mono_find_jit_info (domain
, jit_tls
, &res
, NULL
, &mono_context
,
359 &new_mono_context
, NULL
, &lmf
, &native_offset
, NULL
);
360 while ((ji
!= NULL
) && (current_frame_index
<= call_chain_depth
)) {
361 ips
[current_frame_index
] = MONO_CONTEXT_GET_IP (&new_mono_context
);
362 current_frame_index
++;
363 mono_context
= new_mono_context
;
364 ji
= mono_find_jit_info (domain
, jit_tls
, &res
, NULL
, &mono_context
,
365 &new_mono_context
, NULL
, &lmf
, &native_offset
, NULL
);
371 mono_profiler_stat_call_chain (current_frame_index
, & ips
[0], ctx
);
374 mono_chain_signal (SIG_HANDLER_PARAMS
);
380 SIG_HANDLER_SIGNATURE (sigquit_signal_handler
)
386 /* We use this signal to start the attach agent too */
387 res
= mono_attach_start ();
391 if (mono_thread_info_new_interrupt_enabled ()) {
392 mono_threads_request_thread_dump ();
394 printf ("Full thread dump:\n");
396 mono_threads_request_thread_dump ();
399 * print_thread_dump () skips the current thread, since sending a signal
400 * to it would invoke the signal handler below the sigquit signal handler,
401 * and signal handlers don't create an lmf, so the stack walk could not
404 mono_print_thread_dump (ctx
);
407 mono_chain_signal (SIG_HANDLER_PARAMS
);
411 SIG_HANDLER_SIGNATURE (sigusr2_signal_handler
)
413 gboolean enabled
= mono_trace_is_enabled ();
415 mono_trace_enable (!enabled
);
417 mono_chain_signal (SIG_HANDLER_PARAMS
);
421 add_signal_handler (int signo
, gpointer handler
)
424 struct sigaction previous_sa
;
426 #ifdef MONO_ARCH_USE_SIGACTION
427 sa
.sa_sigaction
= handler
;
428 sigemptyset (&sa
.sa_mask
);
429 sa
.sa_flags
= SA_SIGINFO
;
430 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
432 /*Apple likes to deliver SIGBUS for *0 */
434 if (signo
== SIGSEGV
|| signo
== SIGBUS
) {
436 if (signo
== SIGSEGV
) {
438 sa
.sa_flags
|= SA_ONSTACK
;
441 * libgc will crash when trying to do stack marking for threads which are on
442 * an altstack, so delay the suspend signal after the signal handler has
445 if (mono_gc_get_suspend_signal () != -1)
446 sigaddset (&sa
.sa_mask
, mono_gc_get_suspend_signal ());
449 if (signo
== SIGSEGV
) {
451 * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
455 sigemptyset (&block_mask
);
456 sigaddset (&sa
.sa_mask
, mono_thread_get_abort_signal ());
459 sa
.sa_handler
= handler
;
460 sigemptyset (&sa
.sa_mask
);
463 g_assert (sigaction (signo
, &sa
, &previous_sa
) != -1);
465 /* if there was already a handler in place for this signal, store it */
466 if (! (previous_sa
.sa_flags
& SA_SIGINFO
) &&
467 (SIG_DFL
== previous_sa
.sa_handler
)) {
468 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
470 if (mono_do_signal_chaining
)
471 save_old_signal_handler (signo
, &previous_sa
);
476 remove_signal_handler (int signo
)
479 struct sigaction
*saved_action
= get_saved_signal_handler (signo
);
482 sa
.sa_handler
= SIG_DFL
;
483 sigemptyset (&sa
.sa_mask
);
486 sigaction (signo
, &sa
, NULL
);
488 g_assert (sigaction (signo
, saved_action
, NULL
) != -1);
493 mono_runtime_posix_install_handlers (void)
498 if (mini_get_debug_options ()->handle_sigint
)
499 add_signal_handler (SIGINT
, mono_sigint_signal_handler
);
501 add_signal_handler (SIGFPE
, mono_sigfpe_signal_handler
);
502 add_signal_handler (SIGQUIT
, sigquit_signal_handler
);
503 add_signal_handler (SIGILL
, mono_sigill_signal_handler
);
504 add_signal_handler (SIGBUS
, mono_sigsegv_signal_handler
);
505 if (mono_jit_trace_calls
!= NULL
)
506 add_signal_handler (SIGUSR2
, sigusr2_signal_handler
);
508 if (!mono_thread_info_new_interrupt_enabled ())
509 add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler
);
510 /* it seems to have become a common bug for some programs that run as parents
511 * of many processes to block signal delivery for real time signals.
512 * We try to detect and work around their breakage here.
514 sigemptyset (&signal_set
);
515 sigaddset (&signal_set
, mono_thread_get_abort_signal ());
516 sigprocmask (SIG_UNBLOCK
, &signal_set
, NULL
);
518 signal (SIGPIPE
, SIG_IGN
);
520 add_signal_handler (SIGABRT
, sigabrt_signal_handler
);
523 add_signal_handler (SIGSEGV
, mono_sigsegv_signal_handler
);
526 #ifndef PLATFORM_MACOSX
528 mono_runtime_install_handlers (void)
530 mono_runtime_posix_install_handlers ();
535 mono_runtime_cleanup_handlers (void)
537 if (mini_get_debug_options ()->handle_sigint
)
538 remove_signal_handler (SIGINT
);
540 remove_signal_handler (SIGFPE
);
541 remove_signal_handler (SIGQUIT
);
542 remove_signal_handler (SIGILL
);
543 remove_signal_handler (SIGBUS
);
544 if (mono_jit_trace_calls
!= NULL
)
545 remove_signal_handler (SIGUSR2
);
547 remove_signal_handler (mono_thread_get_abort_signal ());
549 remove_signal_handler (SIGABRT
);
551 remove_signal_handler (SIGSEGV
);
553 free_saved_signal_handlers ();
556 #ifdef HAVE_LINUX_RTC_H
557 #include <linux/rtc.h>
558 #include <sys/ioctl.h>
560 static int rtc_fd
= -1;
563 enable_rtc_timer (gboolean enable
)
566 flags
= fcntl (rtc_fd
, F_GETFL
);
575 if (fcntl (rtc_fd
, F_SETFL
, flags
) == -1) {
584 mono_runtime_shutdown_stat_profiler (void)
586 #ifdef HAVE_LINUX_RTC_H
588 enable_rtc_timer (FALSE
);
593 mono_runtime_setup_stat_profiler (void)
596 struct itimerval itval
;
597 static int inited
= 0;
598 #ifdef HAVE_LINUX_RTC_H
599 const char *rtc_freq
;
600 if (!inited
&& (rtc_freq
= g_getenv ("MONO_RTC"))) {
604 freq
= atoi (rtc_freq
);
607 rtc_fd
= open ("/dev/rtc", O_RDONLY
);
609 perror ("open /dev/rtc");
612 add_signal_handler (SIGPROF
, sigprof_signal_handler
);
613 if (ioctl (rtc_fd
, RTC_IRQP_SET
, freq
) == -1) {
614 perror ("set rtc freq");
617 if (ioctl (rtc_fd
, RTC_PIE_ON
, 0) == -1) {
618 perror ("start rtc");
621 if (fcntl (rtc_fd
, F_SETSIG
, SIGPROF
) == -1) {
625 if (fcntl (rtc_fd
, F_SETOWN
, getpid ()) == -1) {
629 enable_rtc_timer (TRUE
);
636 itval
.it_interval
.tv_usec
= 999;
637 itval
.it_interval
.tv_sec
= 0;
638 itval
.it_value
= itval
.it_interval
;
639 setitimer (ITIMER_PROF
, &itval
, NULL
);
643 add_signal_handler (SIGPROF
, sigprof_signal_handler
);
647 #if !defined(__APPLE__)
649 mono_runtime_syscall_fork ()
651 #if defined(SYS_fork)
652 return (pid_t
) syscall (SYS_fork
);
654 g_assert_not_reached ();
660 mono_gdb_render_native_backtraces (pid_t crashed_pid
)
662 const char *argv
[9];
665 argv
[0] = g_find_program_in_path ("gdb");
666 if (argv
[0] == NULL
) {
671 sprintf (buf1
, "attach %ld", (long) crashed_pid
);
674 argv
[4] = "info threads";
676 argv
[6] = "thread apply all bt";
677 argv
[7] = "--batch";
680 execv (argv
[0], (char**)argv
);
683 #endif /* __native_client__ */
685 #if !defined (__MACH__)
688 mono_thread_state_init_from_handle (MonoThreadUnwindState
*tctx
, MonoNativeThreadId thread_id
, MonoNativeThreadHandle thread_handle
)
690 g_error ("Posix systems don't support mono_thread_state_init_from_handle");