mono/mini/mini-posix.c

   1 /*
   2  * mini-posix.c: POSIX signal handling support for Mono.
   3  *
   4  * Authors:
   5  *   Mono Team (mono-list@lists.ximian.com)
   6  *
   7  * Copyright 2001-2003 Ximian, Inc.
   8  * Copyright 2003-2008 Ximian, Inc.
   9  *
  10  * See LICENSE for licensing information.
  11  */
  12 #include <config.h>
  13 #include <signal.h>
  14 #ifdef HAVE_ALLOCA_H
  15 #include <alloca.h>
  16 #endif
  17 #ifdef HAVE_UNISTD_H
  18 #include <unistd.h>
  19 #endif
  20 #include <math.h>
  21 #ifdef HAVE_SYS_TIME_H
  22 #include <sys/time.h>
  23 #endif
  24 #ifdef HAVE_SYS_SYSCALL_H
  25 #include <sys/syscall.h>
  26 #endif
  27
  28 #include <mono/metadata/assembly.h>
  29 #include <mono/metadata/loader.h>
  30 #include <mono/metadata/tabledefs.h>
  31 #include <mono/metadata/class.h>
  32 #include <mono/metadata/object.h>
  33 #include <mono/metadata/tokentype.h>
  34 #include <mono/metadata/tabledefs.h>
  35 #include <mono/metadata/threads.h>
  36 #include <mono/metadata/appdomain.h>
  37 #include <mono/metadata/debug-helpers.h>
  38 #include <mono/io-layer/io-layer.h>
  39 #include "mono/metadata/profiler.h"
  40 #include <mono/metadata/profiler-private.h>
  41 #include <mono/metadata/mono-config.h>
  42 #include <mono/metadata/environment.h>
  43 #include <mono/metadata/mono-debug.h>
  44 #include <mono/metadata/gc-internal.h>
  45 #include <mono/metadata/threads-types.h>
  46 #include <mono/metadata/verify.h>
  47 #include <mono/metadata/verify-internals.h>
  48 #include <mono/metadata/mempool-internals.h>
  49 #include <mono/metadata/attach.h>
  50 #include <mono/utils/mono-math.h>
  51 #include <mono/utils/mono-compiler.h>
  52 #include <mono/utils/mono-counters.h>
  53 #include <mono/utils/mono-logger-internal.h>
  54 #include <mono/utils/mono-mmap.h>
  55 #include <mono/utils/dtrace.h>
  56
  57 #include "mini.h"
  58 #include <string.h>
  59 #include <ctype.h>
  60 #include "trace.h"
  61 #include "version.h"
  62 #include "debugger-agent.h"
  63
  64 #include "jit-icalls.h"
  65
  66 #if defined(__native_client__)
  67
  68 void
  69 mono_runtime_setup_stat_profiler (void)
  70 {
  71         printf("WARNING: mono_runtime_setup_stat_profiler() called!\n");
  72 }
  73
  74
  75 void
  76 mono_runtime_shutdown_stat_profiler (void)
  77 {
  78 }
  79
  80
  81 gboolean
  82 SIG_HANDLER_SIGNATURE (mono_chain_signal)
  83 {
  84         return FALSE;
  85 }
  86
  87 void
  88 mono_runtime_install_handlers (void)
  89 {
  90 }
  91
  92 void
  93 mono_runtime_shutdown_handlers (void)
  94 {
  95 }
  96
  97 void
  98 mono_runtime_cleanup_handlers (void)
  99 {
 100 }
 101
 102
 103
 104 #else
 105
 106 static GHashTable *mono_saved_signal_handlers = NULL;
 107
 108 static gpointer
 109 get_saved_signal_handler (int signo)
 110 {
 111         if (mono_saved_signal_handlers)
 112                 /* The hash is only modified during startup, so no need for locking */
 113                 return g_hash_table_lookup (mono_saved_signal_handlers, GINT_TO_POINTER (signo));
 114         return NULL;
 115 }
 116
 117 static void
 118 save_old_signal_handler (int signo, struct sigaction *old_action)
 119 {
 120         struct sigaction *handler_to_save = g_malloc (sizeof (struct sigaction));
 121
 122         mono_trace (G_LOG_LEVEL_DEBUG, MONO_TRACE_CONFIG,
 123                                 "Saving old signal handler for signal %d.", signo);
 124
 125         if (! (old_action->sa_flags & SA_SIGINFO)) {
 126                 handler_to_save->sa_handler = old_action->sa_handler;
 127         } else {
 128 #ifdef MONO_ARCH_USE_SIGACTION
 129                 handler_to_save->sa_sigaction = old_action->sa_sigaction;
 130 #endif /* MONO_ARCH_USE_SIGACTION */
 131         }
 132         handler_to_save->sa_mask = old_action->sa_mask;
 133         handler_to_save->sa_flags = old_action->sa_flags;
 134
 135         if (!mono_saved_signal_handlers)
 136                 mono_saved_signal_handlers = g_hash_table_new (NULL, NULL);
 137         g_hash_table_insert (mono_saved_signal_handlers, GINT_TO_POINTER (signo), handler_to_save);
 138 }
 139
 140 static void
 141 free_saved_sig_handler_func (gpointer key, gpointer value, gpointer user_data)
 142 {
 143         g_free (value);
 144 }
 145
 146 static void
 147 free_saved_signal_handlers (void)
 148 {
 149         if (mono_saved_signal_handlers) {
 150                 g_hash_table_foreach (mono_saved_signal_handlers, free_saved_sig_handler_func, NULL);
 151                 g_hash_table_destroy (mono_saved_signal_handlers);
 152                 mono_saved_signal_handlers = NULL;
 153         }
 154 }
 155
 156 /*
 157  * mono_chain_signal:
 158  *
 159  *   Call the original signal handler for the signal given by the arguments, which
 160  * should be the same as for a signal handler. Returns TRUE if the original handler
 161  * was called, false otherwise.
 162  */
 163 gboolean
 164 SIG_HANDLER_SIGNATURE (mono_chain_signal)
 165 {
 166         int signal = _dummy;
 167         struct sigaction *saved_handler = get_saved_signal_handler (signal);
 168
 169         GET_CONTEXT;
 170
 171         if (saved_handler) {
 172                 if (!(saved_handler->sa_flags & SA_SIGINFO)) {
 173                         saved_handler->sa_handler (signal);
 174                 } else {
 175 #ifdef MONO_ARCH_USE_SIGACTION
 176                         saved_handler->sa_sigaction (signal, info, ctx);
 177 #endif /* MONO_ARCH_USE_SIGACTION */
 178                 }
 179                 return TRUE;
 180         }
 181         return FALSE;
 182 }
 183
 184 static void
 185 SIG_HANDLER_SIGNATURE (sigabrt_signal_handler)
 186 {
 187         MonoJitInfo *ji = NULL;
 188         GET_CONTEXT;
 189
 190         if (mono_thread_internal_current ())
 191                 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx));
 192         if (!ji) {
 193         if (mono_chain_signal (SIG_HANDLER_PARAMS))
 194                         return;
 195                 mono_handle_native_sigsegv (SIGABRT, ctx);
 196         }
 197 }
 198
 199 static void
 200 SIG_HANDLER_SIGNATURE (sigusr1_signal_handler)
 201 {
 202         MonoContext mctx;
 203         gboolean running_managed;
 204         MonoException *exc;
 205         MonoInternalThread *thread = mono_thread_internal_current ();
 206         MonoDomain *domain = mono_domain_get ();
 207         void *ji;
 208
 209         GET_CONTEXT;
 210
 211         if (!thread || !domain)
 212                 /* The thread might not have started up yet */
 213                 /* FIXME: Specify the synchronization with start_wrapper () in threads.c */
 214                 return;
 215
 216         if (thread->thread_dump_requested) {
 217                 thread->thread_dump_requested = FALSE;
 218
 219                 mono_print_thread_dump (ctx);
 220         }
 221
 222         /*
 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.
 226          */
 227         /*
 228          * On OpenBSD, ctx can be NULL if we are interrupting poll ().
 229          */
 230         if (ctx) {
 231                 ji = mono_jit_info_table_find (mono_domain_get (), mono_arch_ip_from_context(ctx));
 232                 running_managed = ji != NULL;
 233
 234                 if (mono_debugger_agent_thread_interrupt (ctx, ji))
 235                         return;
 236         } else {
 237                 running_managed = FALSE;
 238         }
 239
 240         /* We can't do handler block checking from metadata since it requires doing
 241          * a stack walk with context.
 242          *
 243          * FIXME add full-aot support.
 244          */
 245 #ifdef MONO_ARCH_HAVE_SIGCTX_TO_MONOCTX
 246         if (!mono_aot_only && ctx) {
 247                 mono_arch_sigctx_to_monoctx (ctx, &mctx);
 248                 if (mono_install_handler_block_guard (thread, &mctx)) {
 249                         return;
 250                 }
 251         }
 252 #endif
 253
 254         exc = mono_thread_request_interruption (running_managed);
 255         if (!exc)
 256                 return;
 257
 258         mono_arch_handle_exception (ctx, exc, FALSE);
 259 }
 260
 261 #if defined(__i386__) || defined(__x86_64__)
 262 #define FULL_STAT_PROFILER_BACKTRACE 1
 263 #define CURRENT_FRAME_GET_BASE_POINTER(f) (* (gpointer*)(f))
 264 #define CURRENT_FRAME_GET_RETURN_ADDRESS(f) (* (((gpointer*)(f)) + 1))
 265 #if MONO_ARCH_STACK_GROWS_UP
 266 #define IS_BEFORE_ON_STACK <
 267 #define IS_AFTER_ON_STACK >
 268 #else
 269 #define IS_BEFORE_ON_STACK >
 270 #define IS_AFTER_ON_STACK <
 271 #endif
 272 #else
 273 #define FULL_STAT_PROFILER_BACKTRACE 0
 274 #endif
 275
 276 #if defined(__ia64__) || defined(__sparc__) || defined(sparc) || defined(__s390__) || defined(s390)
 277
 278 static void
 279 SIG_HANDLER_SIGNATURE (sigprof_signal_handler)
 280 {
 281         if (mono_chain_signal (SIG_HANDLER_PARAMS))
 282                 return;
 283
 284         NOT_IMPLEMENTED;
 285 }
 286
 287 #else
 288
 289 static void
 290 SIG_HANDLER_SIGNATURE (sigprof_signal_handler)
 291 {
 292         int call_chain_depth = mono_profiler_stat_get_call_chain_depth ();
 293         MonoProfilerCallChainStrategy call_chain_strategy = mono_profiler_stat_get_call_chain_strategy ();
 294         GET_CONTEXT;
 295
 296         if (call_chain_depth == 0) {
 297                 mono_profiler_stat_hit (mono_arch_ip_from_context (ctx), ctx);
 298         } else {
 299                 MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 300                 int current_frame_index = 1;
 301                 MonoContext mono_context;
 302                 guchar *ips [call_chain_depth + 1];
 303
 304                 mono_arch_sigctx_to_monoctx (ctx, &mono_context);
 305                 ips [0] = MONO_CONTEXT_GET_IP (&mono_context);
 306
 307                 if (jit_tls != NULL) {
 308                         if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_NATIVE) {
 309 #if FULL_STAT_PROFILER_BACKTRACE
 310                         guchar *current_frame;
 311                         guchar *stack_bottom;
 312                         guchar *stack_top;
 313
 314                         stack_bottom = jit_tls->end_of_stack;
 315                         stack_top = MONO_CONTEXT_GET_SP (&mono_context);
 316                         current_frame = MONO_CONTEXT_GET_BP (&mono_context);
 317
 318                         while ((current_frame_index <= call_chain_depth) &&
 319                                         (stack_bottom IS_BEFORE_ON_STACK (guchar*) current_frame) &&
 320                                         ((guchar*) current_frame IS_BEFORE_ON_STACK stack_top)) {
 321                                 ips [current_frame_index] = CURRENT_FRAME_GET_RETURN_ADDRESS (current_frame);
 322                                 current_frame_index ++;
 323                                 stack_top = current_frame;
 324                                 current_frame = CURRENT_FRAME_GET_BASE_POINTER (current_frame);
 325                         }
 326 #else
 327                                 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_GLIBC;
 328 #endif
 329                         }
 330
 331                         if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_GLIBC) {
 332 #if GLIBC_PROFILER_BACKTRACE
 333                                 current_frame_index = backtrace ((void**) & ips [1], call_chain_depth);
 334 #else
 335                                 call_chain_strategy = MONO_PROFILER_CALL_CHAIN_MANAGED;
 336 #endif
 337                         }
 338
 339                         if (call_chain_strategy == MONO_PROFILER_CALL_CHAIN_MANAGED) {
 340                                 MonoDomain *domain = mono_domain_get ();
 341                                 if (domain != NULL) {
 342                                         MonoLMF *lmf = NULL;
 343                                         MonoJitInfo *ji;
 344                                         MonoJitInfo res;
 345                                         MonoContext new_mono_context;
 346                                         int native_offset;
 347                                         ji = mono_find_jit_info (domain, jit_tls, &res, NULL, &mono_context,
 348                                                         &new_mono_context, NULL, &lmf, &native_offset, NULL);
 349                                         while ((ji != NULL) && (current_frame_index <= call_chain_depth)) {
 350                                                 ips [current_frame_index] = MONO_CONTEXT_GET_IP (&new_mono_context);
 351                                                 current_frame_index ++;
 352                                                 mono_context = 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                                         }
 356                                 }
 357                         }
 358                 }
 359
 360                 mono_profiler_stat_call_chain (current_frame_index, & ips [0], ctx);
 361         }
 362
 363         mono_chain_signal (SIG_HANDLER_PARAMS);
 364 }
 365
 366 #endif
 367
 368 static void
 369 SIG_HANDLER_SIGNATURE (sigquit_signal_handler)
 370 {
 371         gboolean res;
 372
 373         GET_CONTEXT;
 374
 375         /* We use this signal to start the attach agent too */
 376         res = mono_attach_start ();
 377         if (res)
 378                 return;
 379
 380         printf ("Full thread dump:\n");
 381
 382         mono_threads_request_thread_dump ();
 383
 384         /*
 385          * print_thread_dump () skips the current thread, since sending a signal
 386          * to it would invoke the signal handler below the sigquit signal handler,
 387          * and signal handlers don't create an lmf, so the stack walk could not
 388          * be performed.
 389          */
 390         mono_print_thread_dump (ctx);
 391
 392         mono_chain_signal (SIG_HANDLER_PARAMS);
 393 }
 394
 395 static void
 396 SIG_HANDLER_SIGNATURE (sigusr2_signal_handler)
 397 {
 398         gboolean enabled = mono_trace_is_enabled ();
 399
 400         mono_trace_enable (!enabled);
 401
 402         mono_chain_signal (SIG_HANDLER_PARAMS);
 403 }
 404
 405 static void
 406 add_signal_handler (int signo, gpointer handler)
 407 {
 408         struct sigaction sa;
 409         struct sigaction previous_sa;
 410
 411 #ifdef MONO_ARCH_USE_SIGACTION
 412         sa.sa_sigaction = handler;
 413         sigemptyset (&sa.sa_mask);
 414         sa.sa_flags = SA_SIGINFO;
 415 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
 416         if (signo == SIGSEGV) {
 417                 sa.sa_flags |= SA_ONSTACK;
 418
 419                 /*
 420                  * libgc will crash when trying to do stack marking for threads which are on
 421                  * an altstack, so delay the suspend signal after the signal handler has
 422                  * executed.
 423                  */
 424                 if (mono_gc_get_suspend_signal () != -1)
 425                         sigaddset (&sa.sa_mask, mono_gc_get_suspend_signal ());
 426         }
 427 #endif
 428         if (signo == SIGSEGV) {
 429                 /*
 430                  * Delay abort signals while handling SIGSEGVs since they could go unnoticed.
 431                  */
 432                 sigset_t block_mask;
 433
 434                 sigemptyset (&block_mask);
 435                 sigaddset (&sa.sa_mask, mono_thread_get_abort_signal ());
 436         }
 437 #else
 438         sa.sa_handler = handler;
 439         sigemptyset (&sa.sa_mask);
 440         sa.sa_flags = 0;
 441 #endif
 442         g_assert (sigaction (signo, &sa, &previous_sa) != -1);
 443
 444         /* if there was already a handler in place for this signal, store it */
 445         if (! (previous_sa.sa_flags & SA_SIGINFO) &&
 446                         (SIG_DFL == previous_sa.sa_handler)) {
 447                 /* it there is no sa_sigaction function and the sa_handler is default, we can safely ignore this */
 448         } else {
 449                 if (mono_do_signal_chaining)
 450                         save_old_signal_handler (signo, &previous_sa);
 451         }
 452 }
 453
 454 static void
 455 remove_signal_handler (int signo)
 456 {
 457         struct sigaction sa;
 458         struct sigaction *saved_action = get_saved_signal_handler (signo);
 459
 460         if (!saved_action) {
 461                 sa.sa_handler = SIG_DFL;
 462                 sigemptyset (&sa.sa_mask);
 463                 sa.sa_flags = 0;
 464
 465                 sigaction (signo, &sa, NULL);
 466         } else {
 467                 g_assert (sigaction (signo, saved_action, NULL) != -1);
 468         }
 469 }
 470
 471 void
 472 mono_runtime_posix_install_handlers (void)
 473 {
 474
 475         sigset_t signal_set;
 476
 477         if (mini_get_debug_options ()->handle_sigint)
 478                 add_signal_handler (SIGINT, mono_sigint_signal_handler);
 479
 480         add_signal_handler (SIGFPE, mono_sigfpe_signal_handler);
 481         add_signal_handler (SIGQUIT, sigquit_signal_handler);
 482         add_signal_handler (SIGILL, mono_sigill_signal_handler);
 483         add_signal_handler (SIGBUS, mono_sigsegv_signal_handler);
 484         if (mono_jit_trace_calls != NULL)
 485                 add_signal_handler (SIGUSR2, sigusr2_signal_handler);
 486
 487         add_signal_handler (mono_thread_get_abort_signal (), sigusr1_signal_handler);
 488         /* it seems to have become a common bug for some programs that run as parents
 489          * of many processes to block signal delivery for real time signals.
 490          * We try to detect and work around their breakage here.
 491          */
 492         sigemptyset (&signal_set);
 493         sigaddset (&signal_set, mono_thread_get_abort_signal ());
 494         sigprocmask (SIG_UNBLOCK, &signal_set, NULL);
 495
 496         signal (SIGPIPE, SIG_IGN);
 497
 498         add_signal_handler (SIGABRT, sigabrt_signal_handler);
 499
 500         /* catch SIGSEGV */
 501         add_signal_handler (SIGSEGV, mono_sigsegv_signal_handler);
 502 }
 503
 504 #ifndef PLATFORM_MACOSX
 505 void
 506 mono_runtime_install_handlers (void)
 507 {
 508         mono_runtime_posix_install_handlers ();
 509 }
 510 #endif
 511
 512 void
 513 mono_runtime_cleanup_handlers (void)
 514 {
 515         if (mini_get_debug_options ()->handle_sigint)
 516                 remove_signal_handler (SIGINT);
 517
 518         remove_signal_handler (SIGFPE);
 519         remove_signal_handler (SIGQUIT);
 520         remove_signal_handler (SIGILL);
 521         remove_signal_handler (SIGBUS);
 522         if (mono_jit_trace_calls != NULL)
 523                 remove_signal_handler (SIGUSR2);
 524
 525         remove_signal_handler (mono_thread_get_abort_signal ());
 526
 527         remove_signal_handler (SIGABRT);
 528
 529         remove_signal_handler (SIGSEGV);
 530
 531         free_saved_signal_handlers ();
 532 }
 533
 534 #ifdef HAVE_LINUX_RTC_H
 535 #include <linux/rtc.h>
 536 #include <sys/ioctl.h>
 537 #include <fcntl.h>
 538 static int rtc_fd = -1;
 539
 540 static int
 541 enable_rtc_timer (gboolean enable)
 542 {
 543         int flags;
 544         flags = fcntl (rtc_fd, F_GETFL);
 545         if (flags < 0) {
 546                 perror ("getflags");
 547                 return 0;
 548         }
 549         if (enable)
 550                 flags |= FASYNC;
 551         else
 552                 flags &= ~FASYNC;
 553         if (fcntl (rtc_fd, F_SETFL, flags) == -1) {
 554                 perror ("setflags");
 555                 return 0;
 556         }
 557         return 1;
 558 }
 559 #endif
 560
 561 void
 562 mono_runtime_shutdown_stat_profiler (void)
 563 {
 564 #ifdef HAVE_LINUX_RTC_H
 565         if (rtc_fd >= 0)
 566                 enable_rtc_timer (FALSE);
 567 #endif
 568 }
 569
 570 void
 571 mono_runtime_setup_stat_profiler (void)
 572 {
 573 #ifdef ITIMER_PROF
 574         struct itimerval itval;
 575         static int inited = 0;
 576 #ifdef HAVE_LINUX_RTC_H
 577         const char *rtc_freq;
 578         if (!inited && (rtc_freq = g_getenv ("MONO_RTC"))) {
 579                 int freq = 0;
 580                 inited = 1;
 581                 if (*rtc_freq)
 582                         freq = atoi (rtc_freq);
 583                 if (!freq)
 584                         freq = 1024;
 585                 rtc_fd = open ("/dev/rtc", O_RDONLY);
 586                 if (rtc_fd == -1) {
 587                         perror ("open /dev/rtc");
 588                         return;
 589                 }
 590                 add_signal_handler (SIGPROF, sigprof_signal_handler);
 591                 if (ioctl (rtc_fd, RTC_IRQP_SET, freq) == -1) {
 592                         perror ("set rtc freq");
 593                         return;
 594                 }
 595                 if (ioctl (rtc_fd, RTC_PIE_ON, 0) == -1) {
 596                         perror ("start rtc");
 597                         return;
 598                 }
 599                 if (fcntl (rtc_fd, F_SETSIG, SIGPROF) == -1) {
 600                         perror ("setsig");
 601                         return;
 602                 }
 603                 if (fcntl (rtc_fd, F_SETOWN, getpid ()) == -1) {
 604                         perror ("setown");
 605                         return;
 606                 }
 607                 enable_rtc_timer (TRUE);
 608                 return;
 609         }
 610         if (rtc_fd >= 0)
 611                 return;
 612 #endif
 613
 614         itval.it_interval.tv_usec = 999;
 615         itval.it_interval.tv_sec = 0;
 616         itval.it_value = itval.it_interval;
 617         setitimer (ITIMER_PROF, &itval, NULL);
 618         if (inited)
 619                 return;
 620         inited = 1;
 621         add_signal_handler (SIGPROF, sigprof_signal_handler);
 622 #endif
 623 }
 624
 625 #if !defined(__APPLE__)
 626 pid_t
 627 mono_runtime_syscall_fork ()
 628 {
 629 #if defined(SYS_fork)
 630         return (pid_t) syscall (SYS_fork);
 631 #else
 632         g_assert_not_reached ();
 633         return 0;
 634 #endif
 635 }
 636
 637 gboolean
 638 mono_gdb_render_native_backtraces ()
 639 {
 640         const char *argv [9];
 641         char buf1 [128];
 642
 643         argv [0] = g_find_program_in_path ("gdb");
 644         if (argv [0] == NULL) {
 645                 return FALSE;
 646         }
 647
 648         argv [1] = "-ex";
 649         sprintf (buf1, "attach %ld", (long)getpid ());
 650         argv [2] = buf1;
 651         argv [3] = "--ex";
 652         argv [4] = "info threads";
 653         argv [5] = "--ex";
 654         argv [6] = "thread apply all bt";
 655         argv [7] = "--batch";
 656         argv [8] = 0;
 657
 658         execv (argv [0], (char**)argv);
 659
 660         return TRUE;
 661 }
 662 #endif
 663 #endif /* __native_client__ */
 664