mono/mini/exceptions-mips.c

   1 /*
   2  * exceptions-mips.c: exception support for MIPS
   3  *
   4  * Authors:
   5  *   Mark Mason (mason@broadcom.com)
   6  *
   7  * Based on exceptions-ppc.c by:
   8  *   Dietmar Maurer (dietmar@ximian.com)
   9  *   Paolo Molaro (lupus@ximian.com)
  10  *
  11  * (C) 2006 Broadcom
  12  * (C) 2001 Ximian, Inc.
  13  */
  14
  15 #include <config.h>
  16 #include <glib.h>
  17 #include <signal.h>
  18 #include <string.h>
  19 #include <ucontext.h>
  20
  21 #include <mono/arch/mips/mips-codegen.h>
  22 #include <mono/metadata/appdomain.h>
  23 #include <mono/metadata/tabledefs.h>
  24 #include <mono/metadata/threads.h>
  25 #include <mono/metadata/debug-helpers.h>
  26 #include <mono/metadata/exception.h>
  27 #include <mono/metadata/mono-debug.h>
  28
  29 #include "mini.h"
  30 #include "mini-mips.h"
  31
  32 #define GENERIC_EXCEPTION_SIZE 256
  33
  34 /* XXX */
  35 #if 1
  36 #define restore_regs_from_context(ctx_reg,ip_reg,tmp_reg) do {  \
  37         } while (0)
  38 #else
  39 #define restore_regs_from_context(ctx_reg,pc,tmp_reg) do {      \
  40                 int reg;        \
  41                 ppc_lwz (code, pc, G_STRUCT_OFFSET (MonoContext, sc_pc), ctx_reg);      \
  42                 ppc_lmw (code, ppc_r13, ctx_reg, G_STRUCT_OFFSET (MonoContext, sc_regs));       \
  43                 for (reg = 0; reg < MONO_SAVED_FREGS; ++reg) {  \
  44                         ppc_lfd (code, (14 + reg), G_STRUCT_OFFSET(MonoLMF, sc_fpregs) + reg * sizeof (gdouble), ctx_reg);      \
  45                 }       \
  46         } while (0)
  47 #endif
  48
  49 /* nothing to do */
  50 #define setup_context(ctx) do { \
  51                 memset ((ctx), 0, sizeof(*(ctx)));      \
  52         } while (0);
  53
  54 /*
  55  * mono_arch_get_restore_context:
  56  *
  57  * Returns a pointer to a method which restores a previously saved MonoContext.
  58  * The first argument in a0 is the pointer to the MonoContext.
  59  */
  60 gpointer
  61 mono_arch_get_restore_context (void)
  62 {
  63         int i;
  64         guint8 *code;
  65         static guint8 start [128];
  66         static int inited = 0;
  67         guint32 iregs_to_restore;
  68
  69         if (inited)
  70                 return start;
  71         inited = 1;
  72         code = start;
  73
  74         iregs_to_restore = (MONO_ARCH_CALLEE_SAVED_REGS \
  75                             | (1 << mips_sp) | (1 << mips_ra));
  76         for (i = 0; i < MONO_SAVED_GREGS; ++i) {
  77                 if (iregs_to_restore & (1 << i)) {
  78                         mips_lw (code, i, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[i]));
  79                 }
  80         }
  81
  82         /* Get the address to return to */
  83         mips_lw (code, mips_t9, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_pc));
  84
  85         /* jump to the saved IP */
  86         mips_jr (code, mips_t9);
  87         mips_nop (code);
  88
  89         /* never reached */
  90         mips_break (code, 0xff);
  91
  92         g_assert ((code - start) < sizeof(start));
  93         mono_arch_flush_icache (start, code - start);
  94         return start;
  95 }
  96
  97 /*
  98  * mono_arch_get_call_filter:
  99  *
 100  * Returns a pointer to a method which calls an exception filter. We
 101  * also use this function to call finally handlers (we pass NULL as
 102  * @exc object in this case).
 103  *
 104  * This function is invoked as
 105  *      call_handler (MonoContext *ctx, handler)
 106  *
 107  * Where 'handler' is a function to be invoked as:
 108  *      handler (void)
 109  */
 110 gpointer
 111 mono_arch_get_call_filter (void)
 112 {
 113         static guint8 start [320];
 114         static int inited = 0;
 115         guint8 *code;
 116         int alloc_size;
 117         int offset;
 118
 119         if (inited)
 120                 return start;
 121
 122         inited = 1;
 123         code = start;
 124
 125         alloc_size = 64;
 126         g_assert ((alloc_size & (MIPS_STACK_ALIGNMENT-1)) == 0);
 127
 128         mips_addiu (code, mips_sp, mips_sp, -alloc_size);
 129         mips_sw (code, mips_ra, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
 130
 131         /* Save global registers on stack (s0 - s7) */
 132         offset = 16;
 133         mips_sw (code, mips_s0, mips_sp, offset); offset += 4;
 134         mips_sw (code, mips_s1, mips_sp, offset); offset += 4;
 135         mips_sw (code, mips_s2, mips_sp, offset); offset += 4;
 136         mips_sw (code, mips_s3, mips_sp, offset); offset += 4;
 137         mips_sw (code, mips_s4, mips_sp, offset); offset += 4;
 138         mips_sw (code, mips_s5, mips_sp, offset); offset += 4;
 139         mips_sw (code, mips_s6, mips_sp, offset); offset += 4;
 140         mips_sw (code, mips_s7, mips_sp, offset); offset += 4;
 141         mips_sw (code, mips_fp, mips_sp, offset); offset += 4;
 142
 143         /* Restore global registers from MonoContext, including the frame pointer */
 144         mips_lw (code, mips_s0, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s0]));
 145         mips_lw (code, mips_s1, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s1]));
 146         mips_lw (code, mips_s2, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s2]));
 147         mips_lw (code, mips_s3, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s3]));
 148         mips_lw (code, mips_s4, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s4]));
 149         mips_lw (code, mips_s5, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s5]));
 150         mips_lw (code, mips_s6, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s6]));
 151         mips_lw (code, mips_s7, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_s7]));
 152         mips_lw (code, mips_fp, mips_a0, G_STRUCT_OFFSET (MonoContext, sc_regs[mips_fp]));
 153
 154         /* a1 is the handler to call */
 155         mips_move (code, mips_t9, mips_a1);
 156
 157         /* jump to the saved IP */
 158         mips_jalr (code, mips_t9, mips_ra);
 159         mips_nop (code);
 160
 161         /* restore all regs from the stack */
 162         offset = 16;
 163         mips_lw (code, mips_s0, mips_sp, offset); offset += 4;
 164         mips_lw (code, mips_s1, mips_sp, offset); offset += 4;
 165         mips_lw (code, mips_s2, mips_sp, offset); offset += 4;
 166         mips_lw (code, mips_s3, mips_sp, offset); offset += 4;
 167         mips_lw (code, mips_s4, mips_sp, offset); offset += 4;
 168         mips_lw (code, mips_s5, mips_sp, offset); offset += 4;
 169         mips_lw (code, mips_s6, mips_sp, offset); offset += 4;
 170         mips_lw (code, mips_s7, mips_sp, offset); offset += 4;
 171         mips_lw (code, mips_fp, mips_sp, offset); offset += 4;
 172
 173         /* epilog */
 174         mips_lw (code, mips_ra, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
 175         mips_addiu (code, mips_sp, mips_sp, alloc_size);
 176         mips_jr (code, mips_ra);
 177         mips_nop (code);
 178
 179         g_assert ((code - start) < sizeof(start));
 180         mono_arch_flush_icache (start, code - start);
 181         return start;
 182 }
 183
 184 static void
 185 throw_exception (MonoObject *exc, unsigned long eip, unsigned long esp, gboolean rethrow)
 186 {
 187         static void (*restore_context) (MonoContext *);
 188         MonoContext ctx;
 189
 190 #ifdef DEBUG_EXCEPTIONS
 191         g_print ("throw_exception: exc=%p eip=%p esp=%p rethrow=%d\n",
 192                  exc, (void *)eip, (void *) esp, rethrow);
 193 #endif
 194
 195         if (!restore_context)
 196                 restore_context = mono_arch_get_restore_context ();
 197
 198         /* adjust eip so that it point into the call instruction */
 199         eip -= 8;
 200
 201         setup_context (&ctx);
 202
 203         /*g_print  ("stack in throw: %p\n", esp);*/
 204         memcpy (&ctx.sc_regs, (void *)(esp + MIPS_STACK_PARAM_OFFSET),
 205                 sizeof (gulong) * MONO_SAVED_GREGS);
 206 #if 0
 207         memcpy (&ctx.sc_fpregs, fp_regs, sizeof (float) * MONO_SAVED_FREGS);
 208 #else
 209         memset (&ctx.sc_fpregs, 0, sizeof (float) * MONO_SAVED_FREGS);
 210 #endif
 211         MONO_CONTEXT_SET_IP (&ctx, eip);
 212
 213         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 214                 MonoException *mono_ex = (MonoException*)exc;
 215                 if (!rethrow)
 216                         mono_ex->stack_trace = NULL;
 217         }
 218         mono_handle_exception (&ctx, exc, (void *)eip, FALSE);
 219 #ifdef DEBUG_EXCEPTIONS
 220         g_print ("throw_exception: restore to pc=%p sp=%p fp=%p ctx=%p\n",
 221                  (void *) ctx.sc_pc, (void *) ctx.sc_regs[mips_sp],
 222                  (void *) ctx.sc_regs[mips_fp], &ctx);
 223 #endif
 224         restore_context (&ctx);
 225
 226         g_assert_not_reached ();
 227 }
 228
 229 /**
 230  * arch_get_throw_exception_generic:
 231  *
 232  * Returns a function pointer which can be used to raise
 233  * exceptions. The returned function has the following
 234  * signature: void (*func) (MonoException *exc); or
 235  * void (*func) (char *exc_name);
 236  *
 237  */
 238 static gpointer
 239 mono_arch_get_throw_exception_generic (guint8 *start, int size, int by_name, gboolean rethrow)
 240 {
 241         guint8 *code;
 242         int alloc_size, pos, i;
 243
 244         code = start;
 245
 246         //g_print ("mono_arch_get_throw_exception_generic: code=%p\n", code);
 247
 248         pos = 0;
 249         /* XXX - save all the FP regs on the stack ? */
 250
 251         pos += MONO_MAX_IREGS * sizeof(guint32);
 252
 253         alloc_size = MIPS_MINIMAL_STACK_SIZE + pos + 64;
 254         // align to MIPS_STACK_ALIGNMENT bytes
 255         alloc_size += MIPS_STACK_ALIGNMENT - 1;
 256         alloc_size &= ~(MIPS_STACK_ALIGNMENT - 1);
 257
 258         g_assert ((alloc_size & (MIPS_STACK_ALIGNMENT-1)) == 0);
 259         mips_addiu (code, mips_sp, mips_sp, -alloc_size);
 260         mips_sw (code, mips_ra, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
 261
 262         /* Save all the regs on the stack */
 263         for (i = 0; i < MONO_MAX_IREGS; i++) {
 264                 if (i != mips_sp)
 265                         mips_sw (code, i, mips_sp, i*sizeof(guint32) + MIPS_STACK_PARAM_OFFSET);
 266                 else {
 267                         mips_addiu (code, mips_at, mips_sp, alloc_size);
 268                         mips_sw (code, mips_at, mips_sp, i*sizeof(guint32) + MIPS_STACK_PARAM_OFFSET);
 269                 }
 270         }
 271
 272         if (by_name) {
 273                 mips_move (code, mips_a2, mips_a0);
 274                 mips_load (code, mips_a0, mono_defaults.corlib);
 275                 mips_load (code, mips_a1, "System");
 276                 mips_load (code, mips_t9, mono_exception_from_name);
 277                 mips_jalr (code, mips_t9, mips_ra);
 278                 mips_nop (code);
 279                 mips_move (code, mips_a0, mips_v0);
 280         }
 281         /* call throw_exception (exc, ip, sp, rethrow) */
 282
 283         /* exc is already in place in a0 */
 284
 285         /* pointer to ip */
 286         if (by_name)
 287                 mips_lw (code, mips_a1, mips_sp, alloc_size + MIPS_RET_ADDR_OFFSET);
 288         else
 289                 mips_move (code, mips_a1, mips_ra);
 290
 291         /* current sp & rethrow */
 292         mips_move (code, mips_a2, mips_sp);
 293         mips_addiu (code, mips_a3, mips_zero, rethrow);
 294
 295         mips_load (code, mips_t9, throw_exception);
 296         mips_jr (code, mips_t9);
 297         mips_nop (code);
 298         /* we should never reach this breakpoint */
 299         mips_break (code, 0xfe);
 300
 301         g_assert ((code - start) < size);
 302         mono_arch_flush_icache (start, code - start);
 303         return start;
 304 }
 305
 306 /**
 307  * mono_arch_get_rethrow_exception:
 308  *
 309  * Returns a function pointer which can be used to rethrow
 310  * exceptions. The returned function has the following
 311  * signature: void (*func) (MonoException *exc);
 312  *
 313  */
 314 gpointer
 315 mono_arch_get_rethrow_exception (void)
 316 {
 317         static guint8 start [GENERIC_EXCEPTION_SIZE];
 318         static int inited = 0;
 319
 320         if (inited)
 321                 return start;
 322         mono_arch_get_throw_exception_generic (start, sizeof (start), FALSE, TRUE);
 323         inited = 1;
 324         return start;
 325 }
 326
 327 /**
 328  * arch_get_throw_exception:
 329  *
 330  * Returns a function pointer which can be used to raise
 331  * exceptions. The returned function has the following
 332  * signature: void (*func) (MonoException *exc);
 333  * For example to raise an arithmetic exception you can use:
 334  *
 335  * x86_push_imm (code, mono_get_exception_arithmetic ());
 336  * x86_call_code (code, arch_get_throw_exception ());
 337  *
 338  */
 339 gpointer
 340 mono_arch_get_throw_exception (void)
 341 {
 342         static guint8 start [GENERIC_EXCEPTION_SIZE];
 343         static int inited = 0;
 344
 345         if (inited)
 346                 return start;
 347         mono_arch_get_throw_exception_generic (start, sizeof (start), FALSE, FALSE);
 348         inited = 1;
 349         return start;
 350 }
 351
 352 /**
 353  * arch_get_throw_exception_by_name:
 354  *
 355  * Returns a function pointer which can be used to raise
 356  * corlib exceptions. The returned function has the following
 357  * signature: void (*func) (char *exc_name);
 358  * For example to raise an arithmetic exception you can use:
 359  *
 360  * x86_push_imm (code, "ArithmeticException");
 361  * x86_call_code (code, arch_get_throw_exception_by_name ());
 362  *
 363  */
 364 gpointer
 365 mono_arch_get_throw_exception_by_name (void)
 366 {
 367         static guint8 start [GENERIC_EXCEPTION_SIZE];
 368         static int inited = 0;
 369
 370         if (inited)
 371                 return start;
 372         mono_arch_get_throw_exception_generic (start, sizeof (start), TRUE, FALSE);
 373         inited = 1;
 374         return start;
 375 }
 376
 377 static MonoArray *
 378 glist_to_array (GList *list, MonoClass *eclass)
 379 {
 380         MonoDomain *domain = mono_domain_get ();
 381         MonoArray *res;
 382         int len, i;
 383
 384         if (!list)
 385                 return NULL;
 386
 387         len = g_list_length (list);
 388         res = mono_array_new (domain, eclass, len);
 389
 390         for (i = 0; list; list = list->next, i++)
 391                 mono_array_set (res, gpointer, i, list->data);
 392
 393         return res;
 394 }
 395
 396 /* mono_arch_find_jit_info:
 397  *
 398  * This function is used to gather information from @ctx. It returns the
 399  * MonoJitInfo of the corresponding function, unwinds one stack frame and
 400  * stores the resulting context into @new_ctx. It also stores a string
 401  * describing the stack location into @trace (if not NULL), and modifies
 402  * the @lmf if necessary. @native_offset return the IP offset from the
 403  * start of the function or -1 if that info is not available.
 404  */
 405 MonoJitInfo *
 406 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
 407                          MonoJitInfo *res, MonoJitInfo *prev_ji,
 408                          MonoContext *ctx, MonoContext *new_ctx,
 409                          MonoLMF **lmf, gboolean *managed)
 410 {
 411         MonoJitInfo *ji;
 412         gpointer ip = MONO_CONTEXT_GET_IP (ctx);
 413         gpointer fp = MONO_CONTEXT_GET_BP (ctx);
 414         guint32 sp;
 415
 416         /* Avoid costly table lookup during stack overflow */
 417         if (prev_ji && (ip > prev_ji->code_start && ((guint8*)ip < ((guint8*)prev_ji->code_start) + prev_ji->code_size)))
 418                 ji = prev_ji;
 419         else
 420                 ji = mono_jit_info_table_find (domain, ip);
 421
 422         if (managed)
 423                 *managed = FALSE;
 424
 425         *new_ctx = *ctx;
 426         setup_context (new_ctx);
 427
 428         if (ji != NULL) {
 429                 int i;
 430                 gint32 address;
 431                 int offset = 0;
 432
 433                 if (*lmf && (MONO_CONTEXT_GET_BP (ctx) >= (gpointer)(*lmf)->ebp)) {
 434                         /* remove any unused lmf */
 435                         *lmf = (*lmf)->previous_lmf;
 436                 }
 437
 438                 address = (char *)ip - (char *)ji->code_start;
 439
 440                 if (managed)
 441                         if (!ji->method->wrapper_type)
 442                                 *managed = TRUE;
 443
 444                 /* My stack frame */
 445                 fp = MONO_CONTEXT_GET_BP (ctx);
 446
 447                 /* Compute the previous stack frame */
 448                 sp = (guint32)(fp) - (short)(*(guint32 *)(ji->code_start));
 449
 450                 /* Sanity check the frame */
 451                 if (!sp || (sp == 0xffffffff)
 452                     || (sp & 0x07) || (sp < 64*1024)) {
 453 #ifdef DEBUG_EXCEPTIONS
 454                         g_print ("mono_arch_find_jit_info: bad stack sp=%p\n", (void *) sp);
 455 #endif
 456                         return (gpointer)-1;
 457                 }
 458
 459                 if (ji->method->save_lmf && 0) {
 460                         /* only enable this when prologue stops emitting
 461                          * normal save of s-regs when save_lmf is true.
 462                          * Will have to sync with prologue code at that point.
 463                          */
 464                         memcpy (&new_ctx->sc_fpregs,
 465                                 (char*)sp - sizeof (float) * MONO_SAVED_FREGS,
 466                                 sizeof (float) * MONO_SAVED_FREGS);
 467                         memcpy (&new_ctx->sc_regs,
 468                                 (char*)sp - sizeof (float) * MONO_SAVED_FREGS - sizeof (gulong) * MONO_SAVED_GREGS,
 469                                 sizeof (gulong) * MONO_SAVED_GREGS);
 470                 } else if (ji->used_regs) {
 471                         guint32 *insn;
 472                         guint32 mask = ji->used_regs;
 473
 474                         /* these all happen before adjustment of fp */
 475                         /* Look for sw ??, ????(sp) */
 476                         insn = ((guint32 *)ji->code_start) + 1;
 477                         while (!*insn || (*insn & 0xffe00000) == 0xafa00000) {
 478                                 int reg = (*insn >> 16) & 0x1f;
 479                                 mask &= ~(1 << reg);
 480                                 new_ctx->sc_regs [reg] = *(guint32 *)(((guint32)fp) + (short)(*insn & 0x0000ffff));
 481                                 insn++;
 482                         }
 483                         MONO_CONTEXT_SET_SP (new_ctx, sp);
 484                         MONO_CONTEXT_SET_BP (new_ctx, sp);
 485                         /* assert that we found all registers we were supposed to */
 486                         g_assert (!mask);
 487                 }
 488                 /* we substract 8, so that the IP points into the call instruction */
 489                 MONO_CONTEXT_SET_IP (new_ctx, new_ctx->sc_regs[mips_ra] - 8);
 490
 491                 /* Sanity check -- we should have made progress here */
 492                 g_assert (new_ctx->sc_pc != ctx->sc_pc);
 493                 return ji;
 494         } else if (*lmf) {
 495                 if (!(*lmf)->method) {
 496 #ifdef DEBUG_EXCEPTIONS
 497                         g_print ("mono_arch_find_jit_info: bad lmf @ %p\n", (void *) *lmf);
 498 #endif
 499                         return (gpointer)-1;
 500                 }
 501                 g_assert (((*lmf)->magic == MIPS_LMF_MAGIC1) || ((*lmf)->magic == MIPS_LMF_MAGIC2));
 502
 503                 if ((ji = mono_jit_info_table_find (domain, (gpointer)(*lmf)->eip))) {
 504                 } else {
 505                         memset (res, 0, sizeof (MonoJitInfo));
 506                         res->method = (*lmf)->method;
 507                 }
 508                 memcpy (&new_ctx->sc_regs, (*lmf)->iregs, sizeof (gulong) * MONO_SAVED_GREGS);
 509                 memcpy (&new_ctx->sc_fpregs, (*lmf)->fregs, sizeof (float) * MONO_SAVED_FREGS);
 510                 MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip);
 511                 /* ensure that we've made progress */
 512                 g_assert (new_ctx->sc_pc != ctx->sc_pc);
 513                 *lmf = (*lmf)->previous_lmf;
 514
 515                 return ji ? ji : res;
 516         }
 517
 518         return NULL;
 519 }
 520
 521 void
 522 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
 523 {
 524         int i;
 525         struct sigcontext *ctx = (struct sigcontext *)sigctx;
 526
 527         mctx->sc_pc = ctx->sc_pc;
 528         for (i = 0; i < 32; ++i) {
 529                 mctx->sc_regs[i] = ctx->sc_regs[i];
 530                 mctx->sc_fpregs[i] = ctx->sc_fpregs[i];
 531         }
 532 }
 533
 534 void
 535 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
 536 {
 537         int i;
 538         struct sigcontext *ctx = (struct sigcontext *)sigctx;
 539
 540         ctx->sc_pc = mctx->sc_pc;
 541         for (i = 0; i < 32; ++i) {
 542                 ctx->sc_regs[i] = mctx->sc_regs[i];
 543                 ctx->sc_fpregs[i] = mctx->sc_fpregs[i];
 544         }
 545 }
 546
 547 gpointer
 548 mono_arch_ip_from_context (void *sigctx)
 549 {
 550         struct sigcontext *ctx = (struct sigcontext *)sigctx;
 551         return (gpointer)(guint32)ctx->sc_pc;
 552 }
 553
 554 /*
 555  * This is the function called from the signal handler
 556  */
 557 gboolean
 558 mono_arch_handle_exception (void *ctx, gpointer obj, gboolean test_only)
 559 {
 560         MonoContext mctx;
 561         gboolean result;
 562
 563         mono_arch_sigctx_to_monoctx (ctx, &mctx);
 564 #ifdef DEBUG_EXCEPTIONS
 565         g_print ("mono_arch_handle_exception: pc=%p\n", (void *) mctx.sc_pc);
 566 #endif
 567         mono_handle_exception (&mctx, obj, (gpointer)mctx.sc_pc, test_only);
 568         result = TRUE;
 569
 570 #ifdef DEBUG_EXCEPTIONS
 571         g_print ("mono_arch_handle_exception: restore pc=%p\n", (void *)mctx.sc_pc);
 572 #endif
 573         /* restore the context so that returning from the signal handler
 574          * will invoke the catch clause
 575          */
 576         mono_arch_monoctx_to_sigctx (&mctx, ctx);
 577
 578         return result;
 579 }
 580
 581
 582 gboolean
 583 mono_arch_has_unwind_info (gconstpointer addr)
 584 {
 585         return FALSE;
 586 }
 587