mono/mini/mini-exceptions.c

   1 /*
   2  * mini-exceptions.c: generic exception support
   3  *
   4  * Authors:
   5  *   Dietmar Maurer (dietmar@ximian.com)
   6  *
   7  * (C) 2001 Ximian, Inc.
   8  */
   9
  10 #include <config.h>
  11 #include <glib.h>
  12 #include <signal.h>
  13 #include <string.h>
  14
  15 #ifdef HAVE_EXECINFO_H
  16 #include <execinfo.h>
  17 #endif
  18
  19 #include <mono/metadata/appdomain.h>
  20 #include <mono/metadata/tabledefs.h>
  21 #include <mono/metadata/threads.h>
  22 #include <mono/metadata/debug-helpers.h>
  23 #include <mono/metadata/exception.h>
  24 #include <mono/metadata/gc-internal.h>
  25 #include <mono/metadata/mono-debug.h>
  26
  27 #include "mini.h"
  28 #include "trace.h"
  29
  30 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
  31 #include <unistd.h>
  32 #include <sys/mman.h>
  33 #endif
  34
  35 #define IS_ON_SIGALTSTACK(jit_tls) ((jit_tls) && ((guint8*)&(jit_tls) > (guint8*)(jit_tls)->signal_stack) && ((guint8*)&(jit_tls) < ((guint8*)(jit_tls)->signal_stack + (jit_tls)->signal_stack_size)))
  36
  37 #ifndef MONO_ARCH_CONTEXT_DEF
  38 #define MONO_ARCH_CONTEXT_DEF
  39 #endif
  40
  41 #ifndef mono_find_jit_info
  42
  43 /* mono_find_jit_info:
  44  *
  45  * This function is used to gather information from @ctx. It return the
  46  * MonoJitInfo of the corresponding function, unwinds one stack frame and
  47  * stores the resulting context into @new_ctx. It also stores a string
  48  * describing the stack location into @trace (if not NULL), and modifies
  49  * the @lmf if necessary. @native_offset return the IP offset from the
  50  * start of the function or -1 if that info is not available.
  51  */
  52 static MonoJitInfo *
  53 mono_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoJitInfo *res, MonoJitInfo *prev_ji, MonoContext *ctx,
  54                     MonoContext *new_ctx, char **trace, MonoLMF **lmf, int *native_offset,
  55                     gboolean *managed)
  56 {
  57         gboolean managed2;
  58         gpointer ip = MONO_CONTEXT_GET_IP (ctx);
  59         MonoJitInfo *ji;
  60
  61         if (trace)
  62                 *trace = NULL;
  63
  64         if (native_offset)
  65                 *native_offset = -1;
  66
  67         if (managed)
  68                 *managed = FALSE;
  69
  70         ji = mono_arch_find_jit_info (domain, jit_tls, res, prev_ji, ctx, new_ctx, NULL, lmf, NULL, &managed2);
  71
  72         if (ji == (gpointer)-1)
  73                 return ji;
  74
  75         if (managed2 || ji->method->wrapper_type) {
  76                 const char *real_ip, *start;
  77                 gint32 offset;
  78
  79                 start = (const char *)ji->code_start;
  80                 if (!managed2)
  81                         /* ctx->ip points into native code */
  82                         real_ip = (const char*)MONO_CONTEXT_GET_IP (new_ctx);
  83                 else
  84                         real_ip = (const char*)ip;
  85
  86                 if ((real_ip >= start) && (real_ip <= start + ji->code_size))
  87                         offset = real_ip - start;
  88                 else
  89                         offset = -1;
  90
  91                 if (native_offset)
  92                         *native_offset = offset;
  93
  94                 if (managed)
  95                         if (!ji->method->wrapper_type)
  96                                 *managed = TRUE;
  97
  98                 if (trace)
  99                         *trace = mono_debug_print_stack_frame (ji->method, offset, domain);
 100         } else {
 101                 if (trace) {
 102                         char *fname = mono_method_full_name (res->method, TRUE);
 103                         *trace = g_strdup_printf ("in (unmanaged) %s", fname);
 104                         g_free (fname);
 105                 }
 106         }
 107
 108         return ji;
 109 }
 110
 111 #endif /* mono_find_jit_info */
 112
 113 MonoString *
 114 ves_icall_System_Exception_get_trace (MonoException *ex)
 115 {
 116         MonoDomain *domain = mono_domain_get ();
 117         MonoString *res;
 118         MonoArray *ta = ex->trace_ips;
 119         int i, len;
 120         GString *trace_str;
 121
 122         if (ta == NULL)
 123                 /* Exception is not thrown yet */
 124                 return NULL;
 125
 126         len = mono_array_length (ta);
 127         trace_str = g_string_new ("");
 128         for (i = 0; i < len; i++) {
 129                 MonoJitInfo *ji;
 130                 gpointer ip = mono_array_get (ta, gpointer, i);
 131
 132                 ji = mono_jit_info_table_find (domain, ip);
 133                 if (ji == NULL) {
 134                         /* Unmanaged frame */
 135                         g_string_append_printf (trace_str, "in (unmanaged) %p\n", ip);
 136                 } else {
 137                         gchar *location;
 138                         gint32 address;
 139
 140                         address = (char *)ip - (char *)ji->code_start;
 141                         location = mono_debug_print_stack_frame (
 142                                 ji->method, address, ex->object.vtable->domain);
 143
 144                         g_string_append_printf (trace_str, "%s\n", location);
 145                         g_free (location);
 146                 }
 147         }
 148
 149         res = mono_string_new (ex->object.vtable->domain, trace_str->str);
 150         g_string_free (trace_str, TRUE);
 151
 152         return res;
 153 }
 154
 155 MonoArray *
 156 ves_icall_get_trace (MonoException *exc, gint32 skip, MonoBoolean need_file_info)
 157 {
 158         MonoDomain *domain = mono_domain_get ();
 159         MonoArray *res;
 160         MonoArray *ta = exc->trace_ips;
 161         MonoDebugSourceLocation *location;
 162         int i, len;
 163
 164         if (ta == NULL) {
 165                 /* Exception is not thrown yet */
 166                 return mono_array_new (domain, mono_defaults.stack_frame_class, 0);
 167         }
 168
 169         len = mono_array_length (ta);
 170
 171         res = mono_array_new (domain, mono_defaults.stack_frame_class, len > skip ? len - skip : 0);
 172
 173         for (i = skip; i < len; i++) {
 174                 MonoJitInfo *ji;
 175                 MonoStackFrame *sf = (MonoStackFrame *)mono_object_new (domain, mono_defaults.stack_frame_class);
 176                 gpointer ip = mono_array_get (ta, gpointer, i);
 177
 178                 ji = mono_jit_info_table_find (domain, ip);
 179                 if (ji == NULL) {
 180                         /* Unmanaged frame */
 181                         mono_array_setref (res, i, sf);
 182                         continue;
 183                 }
 184
 185                 g_assert (ji != NULL);
 186
 187                 if (ji->method->wrapper_type) {
 188                         char *s;
 189
 190                         sf->method = NULL;
 191                         s = mono_method_full_name (ji->method, TRUE);
 192                         MONO_OBJECT_SETREF (sf, internal_method_name, mono_string_new (domain, s));
 193                         g_free (s);
 194                 }
 195                 else
 196                         MONO_OBJECT_SETREF (sf, method, mono_method_get_object (domain, ji->method, NULL));
 197                 sf->native_offset = (char *)ip - (char *)ji->code_start;
 198
 199                 /*
 200                  * mono_debug_lookup_source_location() returns both the file / line number information
 201                  * and the IL offset.  Note that computing the IL offset is already an expensive
 202                  * operation, so we shouldn't call this method twice.
 203                  */
 204                 location = mono_debug_lookup_source_location (ji->method, sf->native_offset, domain);
 205                 if (location)
 206                         sf->il_offset = location->il_offset;
 207                 else
 208                         sf->il_offset = 0;
 209
 210                 if (need_file_info) {
 211                         if (location) {
 212                                 MONO_OBJECT_SETREF (sf, filename, mono_string_new (domain, location->source_file));
 213                                 sf->line = location->row;
 214                                 sf->column = location->column;
 215                         } else {
 216                                 sf->line = sf->column = 0;
 217                                 sf->filename = NULL;
 218                         }
 219                 }
 220
 221                 mono_debug_free_source_location (location);
 222                 mono_array_setref (res, i, sf);
 223         }
 224
 225         return res;
 226 }
 227
 228 /**
 229  * mono_walk_stack:
 230  * @domain: starting appdomain
 231  * @jit_tls: JIT data for the thread
 232  * @start_ctx: starting state of the stack frame
 233  * @func: callback to call for each stack frame
 234  * @user_data: data passed to the callback
 235  *
 236  * This function walks the stack of a thread, starting from the state
 237  * represented by jit_tls and start_ctx. For each frame the callback
 238  * function is called with the relevant info. The walk ends when no more
 239  * managed stack frames are found or when the callback returns a TRUE value.
 240  * Note that the function can be used to walk the stack of a thread
 241  * different from the current.
 242  */
 243 void
 244 mono_walk_stack (MonoDomain *domain, MonoJitTlsData *jit_tls, MonoContext *start_ctx, MonoStackFrameWalk func, gpointer user_data)
 245 {
 246         MonoLMF *lmf = jit_tls->lmf;
 247         MonoJitInfo *ji, rji;
 248         gint native_offset;
 249         gboolean managed;
 250         MonoContext ctx, new_ctx;
 251
 252         ctx = *start_ctx;
 253
 254         while (MONO_CONTEXT_GET_BP (&ctx) < jit_tls->end_of_stack) {
 255                 /*
 256                  * FIXME: mono_find_jit_info () will need to be able to return a different
 257                  * MonoDomain when apddomain transitions are found on the stack.
 258                  */
 259                 ji = mono_find_jit_info (domain, jit_tls, &rji, NULL, &ctx, &new_ctx, NULL, &lmf, &native_offset, &managed);
 260                 if (!ji || ji == (gpointer)-1)
 261                         return;
 262
 263                 if (func (domain, &new_ctx, ji, user_data))
 264                         return;
 265
 266                 ctx = new_ctx;
 267         }
 268 }
 269
 270 #ifndef CUSTOM_STACK_WALK
 271
 272 void
 273 mono_jit_walk_stack_from_ctx (MonoStackWalk func, MonoContext *start_ctx, gboolean do_il_offset, gpointer user_data)
 274 {
 275         MonoDomain *domain = mono_domain_get ();
 276         MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 277         MonoLMF *lmf = jit_tls->lmf;
 278         MonoJitInfo *ji, rji;
 279         gint native_offset, il_offset;
 280         gboolean managed;
 281         MonoContext ctx, new_ctx;
 282
 283         MONO_ARCH_CONTEXT_DEF
 284
 285         mono_arch_flush_register_windows ();
 286
 287         if (start_ctx) {
 288                 memcpy (&ctx, start_ctx, sizeof (MonoContext));
 289         } else {
 290 #ifdef MONO_INIT_CONTEXT_FROM_CURRENT
 291         MONO_INIT_CONTEXT_FROM_CURRENT (&ctx);
 292 #else
 293     MONO_INIT_CONTEXT_FROM_FUNC (&ctx, mono_jit_walk_stack_from_ctx);
 294 #endif
 295         }
 296
 297         while (MONO_CONTEXT_GET_BP (&ctx) < jit_tls->end_of_stack) {
 298                 ji = mono_find_jit_info (domain, jit_tls, &rji, NULL, &ctx, &new_ctx, NULL, &lmf, &native_offset, &managed);
 299                 g_assert (ji);
 300
 301                 if (ji == (gpointer)-1)
 302                         return;
 303
 304                 if (do_il_offset) {
 305                         MonoDebugSourceLocation *source;
 306
 307                         source = mono_debug_lookup_source_location (ji->method, native_offset, domain);
 308                         il_offset = source ? source->il_offset : -1;
 309                         mono_debug_free_source_location (source);
 310                 } else
 311                         il_offset = -1;
 312
 313                 if (func (ji->method, native_offset, il_offset, managed, user_data))
 314                         return;
 315
 316                 ctx = new_ctx;
 317         }
 318 }
 319
 320 void
 321 mono_jit_walk_stack (MonoStackWalk func, gboolean do_il_offset, gpointer user_data)
 322 {
 323         mono_jit_walk_stack_from_ctx (func, NULL, do_il_offset, user_data);
 324 }
 325
 326 MonoBoolean
 327 ves_icall_get_frame_info (gint32 skip, MonoBoolean need_file_info,
 328                           MonoReflectionMethod **method,
 329                           gint32 *iloffset, gint32 *native_offset,
 330                           MonoString **file, gint32 *line, gint32 *column)
 331 {
 332         MonoDomain *domain = mono_domain_get ();
 333         MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 334         MonoLMF *lmf = jit_tls->lmf;
 335         MonoJitInfo *ji, rji;
 336         MonoContext ctx, new_ctx;
 337         MonoDebugSourceLocation *location;
 338
 339         MONO_ARCH_CONTEXT_DEF;
 340
 341         mono_arch_flush_register_windows ();
 342
 343 #ifdef MONO_INIT_CONTEXT_FROM_CURRENT
 344         MONO_INIT_CONTEXT_FROM_CURRENT (&ctx);
 345 #else
 346         MONO_INIT_CONTEXT_FROM_FUNC (&ctx, ves_icall_get_frame_info);
 347 #endif
 348
 349         /*
 350          * FIXME: This is needed because of the LMF stuff which doesn't exist on ia64.
 351          * Probably the whole mono_find_jit_info () stuff needs to be fixed so this isn't
 352          * needed even on other platforms. This is also true for s390/s390x.
 353          */
 354 #if     !defined(__ia64__) && !defined(__s390__) && !defined(__s390x__)
 355         skip++;
 356 #endif
 357
 358         do {
 359                 ji = mono_find_jit_info (domain, jit_tls, &rji, NULL, &ctx, &new_ctx, NULL, &lmf, native_offset, NULL);
 360
 361                 ctx = new_ctx;
 362
 363                 if (!ji || ji == (gpointer)-1 || MONO_CONTEXT_GET_BP (&ctx) >= jit_tls->end_of_stack)
 364                         return FALSE;
 365
 366                 /* skip all wrappers ??*/
 367                 if (ji->method->wrapper_type == MONO_WRAPPER_RUNTIME_INVOKE ||
 368                     ji->method->wrapper_type == MONO_WRAPPER_XDOMAIN_INVOKE ||
 369                     ji->method->wrapper_type == MONO_WRAPPER_XDOMAIN_DISPATCH ||
 370                     ji->method->wrapper_type == MONO_WRAPPER_REMOTING_INVOKE_WITH_CHECK ||
 371                     ji->method->wrapper_type == MONO_WRAPPER_REMOTING_INVOKE)
 372                         continue;
 373
 374                 skip--;
 375
 376         } while (skip >= 0);
 377
 378         *method = mono_method_get_object (domain, ji->method, NULL);
 379
 380         location = mono_debug_lookup_source_location (ji->method, *native_offset, domain);
 381         if (location)
 382                 *iloffset = location->il_offset;
 383         else
 384                 *iloffset = 0;
 385
 386         if (need_file_info) {
 387                 if (location) {
 388                         *file = mono_string_new (domain, location->source_file);
 389                         *line = location->row;
 390                         *column = location->column;
 391                 } else {
 392                         *file = NULL;
 393                         *line = *column = 0;
 394                 }
 395         }
 396
 397         mono_debug_free_source_location (location);
 398
 399         return TRUE;
 400 }
 401
 402 #endif /* CUSTOM_STACK_WALK */
 403
 404 typedef struct {
 405         guint32 skips;
 406         MonoSecurityFrame *frame;
 407 } MonoFrameSecurityInfo;
 408
 409 static gboolean
 410 callback_get_first_frame_security_info (MonoDomain *domain, MonoContext *ctx, MonoJitInfo *ji, gpointer data)
 411 {
 412         MonoFrameSecurityInfo *si = (MonoFrameSecurityInfo*) data;
 413
 414         /* FIXME: skip all wrappers ?? probably not - case by case testing is required */
 415         if (ji->method->wrapper_type == MONO_WRAPPER_RUNTIME_INVOKE ||
 416             ji->method->wrapper_type == MONO_WRAPPER_XDOMAIN_INVOKE ||
 417             ji->method->wrapper_type == MONO_WRAPPER_XDOMAIN_DISPATCH ||
 418             ji->method->wrapper_type == MONO_WRAPPER_REMOTING_INVOKE_WITH_CHECK ||
 419             ji->method->wrapper_type == MONO_WRAPPER_REMOTING_INVOKE) {
 420                 return FALSE;
 421         }
 422
 423         if (si->skips > 0) {
 424                 si->skips--;
 425                 return FALSE;
 426         }
 427
 428         si->frame = mono_declsec_create_frame (domain, ji);
 429
 430         /* Stop - we only want the first frame (e.g. LinkDemand and InheritanceDemand) */
 431         return TRUE;
 432 }
 433
 434 /**
 435  * ves_icall_System_Security_SecurityFrame_GetSecurityFrame:
 436  * @skip: the number of stack frames to skip
 437  *
 438  * This function returns a the security informations of a single stack frame
 439  * (after the skipped ones). This is required for [NonCas]LinkDemand[Choice]
 440  * and [NonCas]InheritanceDemand[Choice] as only the caller security is
 441  * evaluated.
 442  */
 443 MonoSecurityFrame*
 444 ves_icall_System_Security_SecurityFrame_GetSecurityFrame (gint32 skip)
 445 {
 446         MonoDomain *domain = mono_domain_get ();
 447         MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 448         MonoFrameSecurityInfo si;
 449         MonoContext ctx;
 450
 451         MONO_ARCH_CONTEXT_DEF
 452
 453         MONO_INIT_CONTEXT_FROM_FUNC (&ctx, ves_icall_System_Security_SecurityFrame_GetSecurityFrame);
 454
 455         si.skips = skip;
 456         si.frame = NULL;
 457         mono_walk_stack (domain, jit_tls, &ctx, callback_get_first_frame_security_info, (gpointer)&si);
 458
 459         return (si.skips == 0) ? si.frame : NULL;
 460 }
 461
 462
 463 typedef struct {
 464         guint32 skips;
 465         MonoArray *stack;
 466         guint32 count;
 467         guint32 maximum;
 468 } MonoSecurityStack;
 469
 470 static void
 471 grow_array (MonoSecurityStack *stack)
 472 {
 473         MonoDomain *domain = mono_domain_get ();
 474         guint32 newsize = (stack->maximum << 1);
 475         MonoArray *newstack = mono_array_new (domain, mono_defaults.runtimesecurityframe_class, newsize);
 476         int i;
 477         for (i=0; i < stack->maximum; i++) {
 478                 gpointer frame = mono_array_get (stack->stack, gpointer, i);
 479                 mono_array_setref (newstack, i, frame);
 480         }
 481         stack->maximum = newsize;
 482         stack->stack = newstack;
 483 }
 484
 485 static gboolean
 486 callback_get_stack_frames_security_info (MonoDomain *domain, MonoContext *ctx, MonoJitInfo *ji, gpointer data)
 487 {
 488         MonoSecurityStack *ss = (MonoSecurityStack*) data;
 489
 490         /* FIXME: skip all wrappers ?? probably not - case by case testing is required */
 491         if (ji->method->wrapper_type == MONO_WRAPPER_RUNTIME_INVOKE ||
 492             ji->method->wrapper_type == MONO_WRAPPER_XDOMAIN_INVOKE ||
 493             ji->method->wrapper_type == MONO_WRAPPER_XDOMAIN_DISPATCH ||
 494             ji->method->wrapper_type == MONO_WRAPPER_REMOTING_INVOKE_WITH_CHECK ||
 495             ji->method->wrapper_type == MONO_WRAPPER_REMOTING_INVOKE) {
 496                 return FALSE;
 497         }
 498
 499         if (ss->skips > 0) {
 500                 ss->skips--;
 501                 return FALSE;
 502         }
 503
 504         if (ss->count == ss->maximum)
 505                 grow_array (ss);
 506
 507         mono_array_setref (ss->stack, ss->count++, mono_declsec_create_frame (domain, ji));
 508
 509         /* continue down the stack */
 510         return FALSE;
 511 }
 512
 513 static MonoArray *
 514 glist_to_array (GList *list, MonoClass *eclass)
 515 {
 516         MonoDomain *domain = mono_domain_get ();
 517         MonoArray *res;
 518         int len, i;
 519
 520         if (!list)
 521                 return NULL;
 522
 523         len = g_list_length (list);
 524         res = mono_array_new (domain, eclass, len);
 525
 526         for (i = 0; list; list = list->next, i++)
 527                 mono_array_set (res, gpointer, i, list->data);
 528
 529         return res;
 530 }
 531
 532 /**
 533  * ves_icall_System_Security_SecurityFrame_GetSecurityStack:
 534  * @skip: the number of stack frames to skip
 535  *
 536  * This function returns an managed array of containing the security
 537  * informations for each frame (after the skipped ones). This is used for
 538  * [NonCas]Demand[Choice] where the complete evaluation of the stack is
 539  * required.
 540  */
 541 MonoArray*
 542 ves_icall_System_Security_SecurityFrame_GetSecurityStack (gint32 skip)
 543 {
 544         MonoDomain *domain = mono_domain_get ();
 545         MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 546         MonoSecurityStack ss;
 547         MonoContext ctx;
 548
 549         MONO_ARCH_CONTEXT_DEF
 550
 551         MONO_INIT_CONTEXT_FROM_FUNC (&ctx, ves_icall_System_Security_SecurityFrame_GetSecurityStack);
 552
 553         ss.skips = skip;
 554         ss.count = 0;
 555         ss.maximum = MONO_CAS_INITIAL_STACK_SIZE;
 556         ss.stack = mono_array_new (domain, mono_defaults.runtimesecurityframe_class, ss.maximum);
 557         mono_walk_stack (domain, jit_tls, &ctx, callback_get_stack_frames_security_info, (gpointer)&ss);
 558         /* g_warning ("STACK RESULT: %d out of %d", ss.count, ss.maximum); */
 559         return ss.stack;
 560 }
 561
 562 #ifndef CUSTOM_EXCEPTION_HANDLING
 563
 564 /**
 565  * mono_handle_exception_internal:
 566  * @ctx: saved processor state
 567  * @obj: the exception object
 568  * @test_only: only test if the exception is caught, but dont call handlers
 569  * @out_filter_idx: out parameter. if test_only is true, set to the index of
 570  * the first filter clause which caught the exception.
 571  */
 572 static gboolean
 573 mono_handle_exception_internal (MonoContext *ctx, gpointer obj, gpointer original_ip, gboolean test_only, gint32 *out_filter_idx)
 574 {
 575         MonoDomain *domain = mono_domain_get ();
 576         MonoJitInfo *ji, rji;
 577         static int (*call_filter) (MonoContext *, gpointer) = NULL;
 578         static void (*restore_context) (void *);
 579         MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 580         MonoLMF *lmf = jit_tls->lmf;
 581         MonoArray *initial_trace_ips = NULL;
 582         GList *trace_ips = NULL;
 583         MonoException *mono_ex;
 584         gboolean stack_overflow = FALSE;
 585         MonoContext initial_ctx;
 586         int frame_count = 0;
 587         gboolean gc_disabled = FALSE;
 588         gboolean has_dynamic_methods = FALSE;
 589         gint32 filter_idx, first_filter_idx;
 590
 591         /*
 592          * This function might execute on an alternate signal stack, and Boehm GC
 593          * can't handle that.
 594          * Also, since the altstack is small, stack space intensive operations like
 595          * JIT compilation should be avoided.
 596          */
 597         if (IS_ON_SIGALTSTACK (jit_tls)) {
 598                 /*
 599                  * FIXME: disabling/enabling GC while already on a signal stack might
 600                  * not be safe either.
 601                  */
 602                 /* Have to reenable it later */
 603                 gc_disabled = TRUE;
 604                 mono_gc_disable ();
 605         }
 606
 607         g_assert (ctx != NULL);
 608         if (!obj) {
 609                 MonoException *ex = mono_get_exception_null_reference ();
 610                 MONO_OBJECT_SETREF (ex, message, mono_string_new (domain, "Object reference not set to an instance of an object"));
 611                 obj = (MonoObject *)ex;
 612         }
 613
 614         /*
 615          * Allocate a new exception object instead of the preconstructed ones.
 616          * We can't do this in sigsegv_signal_handler, since GC is not yet
 617          * disabled.
 618          */
 619         if (obj == domain->stack_overflow_ex) {
 620                 obj = mono_get_exception_stack_overflow ();
 621                 stack_overflow = TRUE;
 622         }
 623         else if (obj == domain->null_reference_ex) {
 624                 obj = mono_get_exception_null_reference ();
 625         }
 626
 627         if (mono_object_isinst (obj, mono_defaults.exception_class)) {
 628                 mono_ex = (MonoException*)obj;
 629                 initial_trace_ips = mono_ex->trace_ips;
 630         } else {
 631                 mono_ex = NULL;
 632         }
 633
 634         if (!call_filter)
 635                 call_filter = mono_arch_get_call_filter ();
 636
 637         if (!restore_context)
 638                 restore_context = mono_arch_get_restore_context ();
 639
 640         g_assert (jit_tls->end_of_stack);
 641         g_assert (jit_tls->abort_func);
 642
 643         if (!test_only) {
 644                 MonoContext ctx_cp = *ctx;
 645                 if (mono_trace_is_enabled ())
 646                         g_print ("EXCEPTION handling: %s\n", mono_object_class (obj)->name);
 647                 if (!mono_handle_exception_internal (&ctx_cp, obj, original_ip, TRUE, &first_filter_idx)) {
 648                         if (mono_break_on_exc)
 649                                 G_BREAKPOINT ();
 650                         mono_unhandled_exception (obj);
 651
 652                         if (mono_debugger_unhandled_exception (original_ip, MONO_CONTEXT_GET_SP (ctx), obj)) {
 653                                 /*
 654                                  * If this returns true, then we're running inside the
 655                                  * Mono Debugger and the debugger wants us to restore the
 656                                  * context and continue (normally, the debugger inserts
 657                                  * a breakpoint on the `original_ip', so it regains control
 658                                  * immediately after restoring the context).
 659                                  */
 660                                 MONO_CONTEXT_SET_IP (ctx, original_ip);
 661                                 restore_context (ctx);
 662                                 g_assert_not_reached ();
 663                         }
 664                 }
 665         }
 666
 667         if (out_filter_idx)
 668                 *out_filter_idx = -1;
 669         filter_idx = 0;
 670         initial_ctx = *ctx;
 671         memset (&rji, 0, sizeof (rji));
 672
 673         while (1) {
 674                 MonoContext new_ctx;
 675                 guint32 free_stack;
 676
 677                 ji = mono_find_jit_info (domain, jit_tls, &rji, &rji, ctx, &new_ctx,
 678                                                                  NULL, &lmf, NULL, NULL);
 679                 if (!ji) {
 680                         g_warning ("Exception inside function without unwind info");
 681                         g_assert_not_reached ();
 682                 }
 683
 684                 if (ji != (gpointer)-1) {
 685                         frame_count ++;
 686                         //printf ("M: %s %d %d.\n", mono_method_full_name (ji->method, TRUE), frame_count, test_only);
 687
 688                         if (test_only && ji->method->wrapper_type != MONO_WRAPPER_RUNTIME_INVOKE && mono_ex) {
 689                                 /*
 690                                  * Avoid overwriting the stack trace if the exception is
 691                                  * rethrown. Also avoid giant stack traces during a stack
 692                                  * overflow.
 693                                  */
 694                                 if (!initial_trace_ips && (frame_count < 1000)) {
 695                                         trace_ips = g_list_prepend (trace_ips, MONO_CONTEXT_GET_IP (ctx));
 696                                 }
 697                         }
 698
 699                         if (ji->method->dynamic)
 700                                 has_dynamic_methods = TRUE;
 701
 702                         if (stack_overflow)
 703                                 free_stack = (guint8*)(MONO_CONTEXT_GET_BP (ctx)) - (guint8*)(MONO_CONTEXT_GET_BP (&initial_ctx));
 704                         else
 705                                 free_stack = 0xffffff;
 706
 707                         /*
 708                          * During stack overflow, wait till the unwinding frees some stack
 709                          * space before running handlers/finalizers.
 710                          */
 711                         if ((free_stack > (64 * 1024)) && ji->num_clauses) {
 712                                 int i;
 713
 714                                 for (i = 0; i < ji->num_clauses; i++) {
 715                                         MonoJitExceptionInfo *ei = &ji->clauses [i];
 716                                         gboolean filtered = FALSE;
 717
 718 #ifdef __s390__
 719                                         if (ei->try_start < MONO_CONTEXT_GET_IP (ctx) &&
 720 #else
 721                                         if (ei->try_start <= MONO_CONTEXT_GET_IP (ctx) &&
 722 #endif
 723                                             MONO_CONTEXT_GET_IP (ctx) <= ei->try_end) {
 724                                                 /* catch block */
 725
 726                                                 if ((ei->flags == MONO_EXCEPTION_CLAUSE_NONE) || (ei->flags == MONO_EXCEPTION_CLAUSE_FILTER)) {
 727                                                         /* store the exception object in cfg->excvar */
 728                                                         g_assert (ei->exvar_offset);
 729                                                         *((gpointer *)(gpointer)((char *)MONO_CONTEXT_GET_BP (ctx) + ei->exvar_offset)) = obj;
 730                                                 }
 731
 732                                                 if (ei->flags == MONO_EXCEPTION_CLAUSE_FILTER) {
 733                                                         // mono_debugger_handle_exception (ei->data.filter, MONO_CONTEXT_GET_SP (ctx), obj);
 734                                                         if (test_only) {
 735                                                                 filtered = call_filter (ctx, ei->data.filter);
 736                                                                 if (filtered && out_filter_idx)
 737                                                                         *out_filter_idx = filter_idx;
 738                                                         }
 739                                                         else {
 740                                                                 /*
 741                                                                  * Filter clauses should only be run in the
 742                                                                  * first pass of exception handling.
 743                                                                  */
 744                                                                 filtered = (filter_idx == first_filter_idx);
 745                                                         }
 746                                                         filter_idx ++;
 747                                                 }
 748
 749                                                 if ((ei->flags == MONO_EXCEPTION_CLAUSE_NONE &&
 750                                                      mono_object_isinst (obj, ei->data.catch_class)) || filtered) {
 751                                                         if (test_only) {
 752                                                                 if (mono_ex && !initial_trace_ips) {
 753                                                                         trace_ips = g_list_reverse (trace_ips);
 754                                                                         MONO_OBJECT_SETREF (mono_ex, trace_ips, glist_to_array (trace_ips, mono_defaults.int_class));
 755                                                                         if (has_dynamic_methods)
 756                                                                                 /* These methods could go away anytime, so compute the stack trace now */
 757                                                                                 MONO_OBJECT_SETREF (mono_ex, stack_trace, ves_icall_System_Exception_get_trace (mono_ex));
 758                                                                 }
 759                                                                 g_list_free (trace_ips);
 760
 761                                                                 if (gc_disabled)
 762                                                                         mono_gc_enable ();
 763                                                                 return TRUE;
 764                                                         }
 765                                                         if (mono_trace_is_enabled () && mono_trace_eval (ji->method))
 766                                                                 g_print ("EXCEPTION: catch found at clause %d of %s\n", i, mono_method_full_name (ji->method, TRUE));
 767                                                         mono_debugger_handle_exception (ei->handler_start, MONO_CONTEXT_GET_SP (ctx), obj);
 768                                                         MONO_CONTEXT_SET_IP (ctx, ei->handler_start);
 769                                                         jit_tls->lmf = lmf;
 770
 771                                                         if (gc_disabled)
 772                                                                 mono_gc_enable ();
 773                                                         return 0;
 774                                                 }
 775                                                 if (!test_only && ei->try_start <= MONO_CONTEXT_GET_IP (ctx) &&
 776                                                     MONO_CONTEXT_GET_IP (ctx) < ei->try_end &&
 777                                                     (ei->flags & MONO_EXCEPTION_CLAUSE_FINALLY)) {
 778                                                         if (mono_trace_is_enabled () && mono_trace_eval (ji->method))
 779                                                                 g_print ("EXCEPTION: finally clause %d of %s\n", i, mono_method_full_name (ji->method, TRUE));
 780                                                         mono_debugger_handle_exception (ei->handler_start, MONO_CONTEXT_GET_SP (ctx), obj);
 781                                                         call_filter (ctx, ei->handler_start);
 782                                                 }
 783
 784                                         }
 785                                 }
 786                         }
 787                 }
 788
 789                 *ctx = new_ctx;
 790
 791                 if (ji == (gpointer)-1) {
 792                         if (gc_disabled)
 793                                 mono_gc_enable ();
 794
 795                         if (!test_only) {
 796                                 jit_tls->lmf = lmf;
 797
 798                                 if (IS_ON_SIGALTSTACK (jit_tls)) {
 799                                         /* Switch back to normal stack */
 800                                         if (stack_overflow) {
 801                                                 /* Free up some stack space */
 802                                                 MONO_CONTEXT_SET_SP (&initial_ctx, (gssize)(MONO_CONTEXT_GET_SP (&initial_ctx)) + (64 * 1024));
 803                                                 g_assert ((gssize)MONO_CONTEXT_GET_SP (&initial_ctx) < (gssize)jit_tls->end_of_stack);
 804                                         }
 805                                         MONO_CONTEXT_SET_IP (&initial_ctx, (gssize)jit_tls->abort_func);
 806                                         restore_context (&initial_ctx);
 807                                 }
 808                                 else
 809                                         jit_tls->abort_func (obj);
 810                                 g_assert_not_reached ();
 811                         } else {
 812                                 if (mono_ex && !initial_trace_ips) {
 813                                         trace_ips = g_list_reverse (trace_ips);
 814                                         MONO_OBJECT_SETREF (mono_ex, trace_ips, glist_to_array (trace_ips, mono_defaults.int_class));
 815                                         if (has_dynamic_methods)
 816                                                 /* These methods could go away anytime, so compute the stack trace now */
 817                                                 MONO_OBJECT_SETREF (mono_ex, stack_trace, ves_icall_System_Exception_get_trace (mono_ex));
 818                                 }
 819                                 g_list_free (trace_ips);
 820                                 return FALSE;
 821                         }
 822                 }
 823         }
 824
 825         g_assert_not_reached ();
 826 }
 827
 828 /**
 829  * mono_debugger_run_finally:
 830  * @start_ctx: saved processor state
 831  *
 832  * This method is called by the Mono Debugger to call all `finally' clauses of the
 833  * current stack frame.  It's used when the user issues a `return' command to make
 834  * the current stack frame return.  After returning from this method, the debugger
 835  * unwinds the stack one frame and gives control back to the user.
 836  *
 837  * NOTE: This method is only used when running inside the Mono Debugger.
 838  */
 839 void
 840 mono_debugger_run_finally (MonoContext *start_ctx)
 841 {
 842         static int (*call_filter) (MonoContext *, gpointer) = NULL;
 843         MonoDomain *domain = mono_domain_get ();
 844         MonoJitTlsData *jit_tls = TlsGetValue (mono_jit_tls_id);
 845         MonoLMF *lmf = jit_tls->lmf;
 846         MonoContext ctx, new_ctx;
 847         MonoJitInfo *ji, rji;
 848         int i;
 849
 850         ctx = *start_ctx;
 851
 852         ji = mono_find_jit_info (domain, jit_tls, &rji, NULL, &ctx, &new_ctx, NULL, &lmf, NULL, NULL);
 853         if (!ji || ji == (gpointer)-1)
 854                 return;
 855
 856         if (!call_filter)
 857                 call_filter = mono_arch_get_call_filter ();
 858
 859         for (i = 0; i < ji->num_clauses; i++) {
 860                 MonoJitExceptionInfo *ei = &ji->clauses [i];
 861
 862                 if ((ei->try_start <= MONO_CONTEXT_GET_IP (&ctx)) &&
 863                     (MONO_CONTEXT_GET_IP (&ctx) < ei->try_end) &&
 864                     (ei->flags & MONO_EXCEPTION_CLAUSE_FINALLY)) {
 865                         call_filter (&ctx, ei->handler_start);
 866                 }
 867         }
 868 }
 869
 870 /**
 871  * mono_handle_exception:
 872  * @ctx: saved processor state
 873  * @obj: the exception object
 874  * @test_only: only test if the exception is caught, but dont call handlers
 875  */
 876 gboolean
 877 mono_handle_exception (MonoContext *ctx, gpointer obj, gpointer original_ip, gboolean test_only)
 878 {
 879         return mono_handle_exception_internal (ctx, obj, original_ip, test_only, NULL);
 880 }
 881
 882 #endif /* CUSTOM_EXCEPTION_HANDLING */
 883
 884 #ifdef MONO_ARCH_SIGSEGV_ON_ALTSTACK
 885
 886 void
 887 mono_setup_altstack (MonoJitTlsData *tls)
 888 {
 889         pthread_t self = pthread_self();
 890         pthread_attr_t attr;
 891         size_t stsize = 0;
 892         struct sigaltstack sa;
 893         guint8 *staddr = NULL;
 894         guint8 *current = (guint8*)&staddr;
 895
 896         if (mono_running_on_valgrind ())
 897                 return;
 898
 899         /* Determine stack boundaries */
 900         pthread_attr_init( &attr );
 901 #ifdef HAVE_PTHREAD_GETATTR_NP
 902         pthread_getattr_np( self, &attr );
 903 #else
 904 #ifdef HAVE_PTHREAD_ATTR_GET_NP
 905         pthread_attr_get_np( self, &attr );
 906 #elif defined(sun)
 907         pthread_attr_getstacksize( &attr, &stsize );
 908 #else
 909 #error "Not implemented"
 910 #endif
 911 #endif
 912 #ifndef sun
 913         pthread_attr_getstack( &attr, (void**)&staddr, &stsize );
 914 #endif
 915
 916         g_assert (staddr);
 917
 918         g_assert ((current > staddr) && (current < staddr + stsize));
 919
 920         tls->end_of_stack = staddr + stsize;
 921
 922         /*
 923          * threads created by nptl does not seem to have a guard page, and
 924          * since the main thread is not created by us, we can't even set one.
 925          * Increasing stsize fools the SIGSEGV signal handler into thinking this
 926          * is a stack overflow exception.
 927          */
 928         tls->stack_size = stsize + getpagesize ();
 929
 930         /* Setup an alternate signal stack */
 931         tls->signal_stack = mmap (0, MONO_ARCH_SIGNAL_STACK_SIZE, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
 932         tls->signal_stack_size = MONO_ARCH_SIGNAL_STACK_SIZE;
 933
 934         g_assert (tls->signal_stack);
 935
 936         sa.ss_sp = tls->signal_stack;
 937         sa.ss_size = MONO_ARCH_SIGNAL_STACK_SIZE;
 938         sa.ss_flags = SS_ONSTACK;
 939         sigaltstack (&sa, NULL);
 940 }
 941
 942 void
 943 mono_free_altstack (MonoJitTlsData *tls)
 944 {
 945         struct sigaltstack sa;
 946         int err;
 947
 948         sa.ss_sp = tls->signal_stack;
 949         sa.ss_size = MONO_ARCH_SIGNAL_STACK_SIZE;
 950         sa.ss_flags = SS_DISABLE;
 951         err = sigaltstack  (&sa, NULL);
 952         g_assert (err == 0);
 953
 954         if (tls->signal_stack)
 955                 munmap (tls->signal_stack, MONO_ARCH_SIGNAL_STACK_SIZE);
 956 }
 957
 958 #endif /* MONO_ARCH_SIGSEGV_ON_ALTSTACK */
 959
 960 static gboolean
 961 print_stack_frame (MonoMethod *method, gint32 native_offset, gint32 il_offset, gboolean managed, gpointer data)
 962 {
 963         FILE *stream = (FILE*)data;
 964
 965         if (method) {
 966                 gchar *location = mono_debug_print_stack_frame (method, native_offset, mono_domain_get ());
 967                 fprintf (stream, "  %s\n", location);
 968                 g_free (location);
 969         } else
 970                 fprintf (stream, "  at <unknown> <0x%05x>\n", native_offset);
 971
 972         return FALSE;
 973 }
 974
 975 /*
 976  * mono_handle_native_sigsegv:
 977  *
 978  *   Handle a SIGSEGV received while in native code by printing diagnostic
 979  * information and aborting.
 980  */
 981 void
 982 mono_handle_native_sigsegv (int signal, void *ctx)
 983 {
 984 #ifndef PLATFORM_WIN32
 985         struct sigaction sa;
 986 #endif
 987         const char *signal_str = (signal == SIGSEGV) ? "SIGSEGV" : "SIGABRT";
 988
 989
 990         /*
 991          * A SIGSEGV indicates something went very wrong so we can no longer depend
 992          * on anything working. So try to print out lots of diagnostics, starting
 993          * with ones which have a greater chance of working.
 994          */
 995         fprintf (stderr,
 996                          "\n"
 997                          "=================================================================\n"
 998                          "Got a %s while executing native code. This usually indicates\n"
 999                          "a fatal error in the mono runtime or one of the native libraries \n"
1000                          "used by your application.\n"
1001                          "=================================================================\n"
1002                          "\n", signal_str);
1003
1004         fprintf (stderr, "Stacktrace:\n\n");
1005
1006         mono_jit_walk_stack (print_stack_frame, TRUE, stderr);
1007
1008         fflush (stderr);
1009
1010 #ifdef HAVE_BACKTRACE_SYMBOLS
1011  {
1012         void *array [256];
1013         char **names;
1014         int i, size;
1015
1016         fprintf (stderr, "\nNative stacktrace:\n\n");
1017
1018         size = backtrace (array, 256);
1019         names = backtrace_symbols (array, size);
1020         for (i =0; i < size; ++i) {
1021                 fprintf (stderr, "\t%s\n", names [i]);
1022         }
1023         free (names);
1024  }
1025
1026         fflush (stderr);
1027 #endif
1028
1029 #ifndef PLATFORM_WIN32
1030
1031         /* Remove our SIGABRT handler */
1032         sa.sa_handler = SIG_DFL;
1033         sigemptyset (&sa.sa_mask);
1034         sa.sa_flags = 0;
1035
1036         g_assert (sigaction (SIGABRT, &sa, NULL) != -1);
1037
1038 #endif
1039
1040         abort ();
1041 }
1042
1043 /*
1044  * mono_print_thread_dump:
1045  *
1046  *   Print information about the current thread to stdout.
1047  */
1048 void
1049 mono_print_thread_dump (void *sigctx)
1050 {
1051         MonoThread *thread = mono_thread_current ();
1052 #ifdef __i386__
1053         MonoContext ctx;
1054 #endif
1055         char *name;
1056         GError *error = NULL;
1057
1058         if (thread->name) {
1059                 name = g_utf16_to_utf8 (thread->name, thread->name_len, NULL, NULL, &error);
1060                 g_assert (!error);
1061                 fprintf (stdout, "\n\"%s\"", name);
1062                 g_free (name);
1063         }
1064         else
1065                 fprintf (stdout, "\n\"\"");
1066
1067         fprintf (stdout, " tid=0x%p this=0x%p:\n", (gpointer)(gsize)thread->tid, thread);
1068
1069         /* FIXME: */
1070 #ifdef __i386__
1071         mono_arch_sigctx_to_monoctx (sigctx, &ctx);
1072
1073         mono_jit_walk_stack_from_ctx (print_stack_frame, &ctx, TRUE, stdout);
1074 #else
1075         printf ("\t<Stack traces in thread dumps not supported on this platform>\n");
1076 #endif
1077
1078         fflush (stdout);
1079 }