mono/mini/exceptions-s390x.c

   1 /*------------------------------------------------------------------*/
   2 /*                                                                  */
   3 /* Name        - exceptions-s390.c                                  */
   4 /*                                                                  */
   5 /* Function    - Exception support for S/390.                       */
   6 /*                                                                  */
   7 /* Name        - Neale Ferguson (Neale.Ferguson@SoftwareAG-usa.com) */
   8 /*                                                                  */
   9 /* Date        - January, 2004                                      */
  10 /*                                                                  */
  11 /* Derivation  - From exceptions-x86 & exceptions-ppc               */
  12 /*               Paolo Molaro (lupus@ximian.com)                    */
  13 /*               Dietmar Maurer (dietmar@ximian.com)                */
  14 /*                                                                  */
  15 /* Copyright   - 2001 Ximian, Inc.                                  */
  16 /*                                                                  */
  17 /*------------------------------------------------------------------*/
  18
  19 /*------------------------------------------------------------------*/
  20 /*                 D e f i n e s                                    */
  21 /*------------------------------------------------------------------*/
  22
  23 #define S390_CALLFILTER_INTREGS         S390_MINIMAL_STACK_SIZE
  24 #define S390_CALLFILTER_FLTREGS         (S390_CALLFILTER_INTREGS+(16*sizeof(gulong)))
  25 #define S390_CALLFILTER_ACCREGS         (S390_CALLFILTER_FLTREGS+(16*sizeof(gdouble)))
  26 #define S390_CALLFILTER_SIZE            (S390_CALLFILTER_ACCREGS+(16*sizeof(gint32)))
  27
  28 #define S390_THROWSTACK_ACCPRM          S390_MINIMAL_STACK_SIZE
  29 #define S390_THROWSTACK_FPCPRM          (S390_THROWSTACK_ACCPRM+sizeof(gpointer))
  30 #define S390_THROWSTACK_RETHROW         (S390_THROWSTACK_FPCPRM+sizeof(gulong))
  31 #define S390_THROWSTACK_INTREGS         (S390_THROWSTACK_RETHROW+sizeof(gboolean))
  32 #define S390_THROWSTACK_FLTREGS         (S390_THROWSTACK_INTREGS+(16*sizeof(gulong)))
  33 #define S390_THROWSTACK_ACCREGS         (S390_THROWSTACK_FLTREGS+(16*sizeof(gdouble)))
  34 #define S390_THROWSTACK_SIZE            (S390_THROWSTACK_ACCREGS+(16*sizeof(gint32)))
  35
  36 #define SZ_THROW        384
  37
  38 /*========================= End of Defines =========================*/
  39
  40 /*------------------------------------------------------------------*/
  41 /*                 I n c l u d e s                                  */
  42 /*------------------------------------------------------------------*/
  43
  44 #include <config.h>
  45 #include <glib.h>
  46 #include <signal.h>
  47 #include <string.h>
  48 #include <ucontext.h>
  49
  50 #include <mono/arch/s390x/s390x-codegen.h>
  51 #include <mono/metadata/appdomain.h>
  52 #include <mono/metadata/tabledefs.h>
  53 #include <mono/metadata/threads.h>
  54 #include <mono/metadata/debug-helpers.h>
  55 #include <mono/metadata/exception.h>
  56 #include <mono/metadata/mono-debug.h>
  57
  58 #include "mini.h"
  59 #include "mini-s390x.h"
  60
  61 /*========================= End of Includes ========================*/
  62
  63 /*------------------------------------------------------------------*/
  64 /*                   P r o t o t y p e s                            */
  65 /*------------------------------------------------------------------*/
  66
  67 gboolean mono_arch_handle_exception (void     *ctx,
  68                                      gpointer obj,
  69                                      gboolean test_only);
  70
  71 /*========================= End of Prototypes ======================*/
  72
  73 /*------------------------------------------------------------------*/
  74 /*                 G l o b a l   V a r i a b l e s                  */
  75 /*------------------------------------------------------------------*/
  76
  77 typedef enum {
  78         by_none,
  79         by_token
  80 } throwType;
  81
  82 /*====================== End of Global Variables ===================*/
  83
  84 /*------------------------------------------------------------------*/
  85 /*                                                                  */
  86 /* Name         - mono_arch_has_unwind_info                         */
  87 /*                                                                  */
  88 /* Function     - Tests if a function has a DWARF exception table   */
  89 /*                that is able to restore all caller saved registers*/
  90 /*                                                                  */
  91 /*------------------------------------------------------------------*/
  92
  93 gboolean
  94 mono_arch_has_unwind_info (gconstpointer addr)
  95 {
  96         return FALSE;
  97 }
  98
  99 /*========================= End of Function ========================*/
 100
 101 /*------------------------------------------------------------------*/
 102 /*                                                                  */
 103 /* Name         - mono_arch_get_call_filter                         */
 104 /*                                                                  */
 105 /* Function     - Return a pointer to a method which calls an       */
 106 /*                exception filter. We also use this function to    */
 107 /*                call finally handlers (we pass NULL as @exc       */
 108 /*                object in this case).                             */
 109 /*                                                                  */
 110 /*------------------------------------------------------------------*/
 111
 112 gpointer
 113 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
 114 {
 115         static guint8 *start;
 116         static int inited = 0;
 117         guint8 *code;
 118         int alloc_size, pos, i;
 119
 120         g_assert (!aot);
 121         if (info)
 122                 *info = NULL;
 123
 124         if (inited)
 125                 return start;
 126
 127         inited = 1;
 128         /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */
 129         code = start = mono_global_codeman_reserve (512);
 130
 131         s390_stmg (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 132         s390_lgr  (code, s390_r14, STK_BASE);
 133         alloc_size = S390_ALIGN(S390_CALLFILTER_SIZE, S390_STACK_ALIGNMENT);
 134         s390_aghi (code, STK_BASE, -alloc_size);
 135         s390_stg  (code, s390_r14, 0, STK_BASE, 0);
 136
 137         /*------------------------------------------------------*/
 138         /* save general registers on stack                      */
 139         /*------------------------------------------------------*/
 140         s390_stmg (code, s390_r0, STK_BASE, STK_BASE, S390_CALLFILTER_INTREGS);
 141
 142         /*------------------------------------------------------*/
 143         /* save floating point registers on stack               */
 144         /*------------------------------------------------------*/
 145         pos = S390_CALLFILTER_FLTREGS;
 146         for (i = 0; i < 16; ++i) {
 147                 s390_std (code, i, 0, STK_BASE, pos);
 148                 pos += sizeof (gdouble);
 149         }
 150
 151         /*------------------------------------------------------*/
 152         /* save access registers on stack                       */
 153         /*------------------------------------------------------*/
 154         s390_stam (code, s390_a0, s390_a15, STK_BASE, S390_CALLFILTER_ACCREGS);
 155
 156         /*------------------------------------------------------*/
 157         /* Get A(Context)                                       */
 158         /*------------------------------------------------------*/
 159         s390_lgr  (code, s390_r13, s390_r2);
 160
 161         /*------------------------------------------------------*/
 162         /* Get A(Handler Entry Point)                           */
 163         /*------------------------------------------------------*/
 164         s390_lgr  (code, s390_r0, s390_r3);
 165
 166         /*------------------------------------------------------*/
 167         /* Set parameter register with Exception                */
 168         /*------------------------------------------------------*/
 169         s390_lgr  (code, s390_r2, s390_r4);
 170
 171         /*------------------------------------------------------*/
 172         /* Load all registers with values from the context      */
 173         /*------------------------------------------------------*/
 174         s390_lmg  (code, s390_r3, s390_r12, s390_r13,
 175                    G_STRUCT_OFFSET(MonoContext, uc_mcontext.gregs[3]));
 176         pos = G_STRUCT_OFFSET(MonoContext, uc_mcontext.fpregs.fprs[0]);
 177         for (i = 0; i < 16; ++i) {
 178                 s390_ld  (code, i, 0, s390_r13, pos);
 179                 pos += sizeof(gdouble);
 180         }
 181
 182         /*------------------------------------------------------*/
 183         /* Go call filter                                       */
 184         /*------------------------------------------------------*/
 185         s390_lgr  (code, s390_r1, s390_r0);
 186         s390_basr (code, s390_r14, s390_r1);
 187
 188         /*------------------------------------------------------*/
 189         /* Save return value                                    */
 190         /*------------------------------------------------------*/
 191         s390_lgr  (code, s390_r14, s390_r2);
 192
 193         /*------------------------------------------------------*/
 194         /* Restore all the regs from the stack                  */
 195         /*------------------------------------------------------*/
 196         s390_lmg  (code, s390_r0, s390_r13, STK_BASE, S390_CALLFILTER_INTREGS);
 197         pos = S390_CALLFILTER_FLTREGS;
 198         for (i = 0; i < 16; ++i) {
 199                 s390_ld (code, i, 0, STK_BASE, pos);
 200                 pos += sizeof (gdouble);
 201         }
 202
 203         s390_lgr  (code, s390_r2, s390_r14);
 204         s390_lam  (code, s390_a0, s390_a15, STK_BASE, S390_CALLFILTER_ACCREGS);
 205         s390_aghi (code, s390_r15, alloc_size);
 206         s390_lmg  (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 207         s390_br   (code, s390_r14);
 208
 209         g_assert ((code - start) < SZ_THROW);
 210         return start;
 211 }
 212
 213 /*========================= End of Function ========================*/
 214
 215 /*------------------------------------------------------------------*/
 216 /*                                                                  */
 217 /* Name         - throw_exception.                                  */
 218 /*                                                                  */
 219 /* Function     - Raise an exception based on the parameters passed.*/
 220 /*                                                                  */
 221 /*------------------------------------------------------------------*/
 222
 223 static void
 224 throw_exception (MonoObject *exc, unsigned long ip, unsigned long sp,
 225                  gulong *int_regs, gdouble *fp_regs, gint32 *acc_regs,
 226                  guint fpc, gboolean rethrow)
 227 {
 228         MonoContext ctx;
 229         int iReg;
 230         static void (*restore_context) (MonoContext *);
 231
 232         if (!restore_context)
 233                 restore_context = mono_get_restore_context();
 234
 235         memset(&ctx, 0, sizeof(ctx));
 236
 237         getcontext(&ctx);
 238
 239         /* adjust eip so that it point into the call instruction */
 240         ip -= 2;
 241
 242         for (iReg = 0; iReg < 16; iReg++) {
 243                 ctx.uc_mcontext.gregs[iReg]         = int_regs[iReg];
 244                 ctx.uc_mcontext.fpregs.fprs[iReg].d = fp_regs[iReg];
 245                 ctx.uc_mcontext.aregs[iReg]         = acc_regs[iReg];
 246         }
 247
 248         ctx.uc_mcontext.fpregs.fpc = fpc;
 249
 250         MONO_CONTEXT_SET_BP (&ctx, sp);
 251         MONO_CONTEXT_SET_IP (&ctx, ip);
 252
 253         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 254                 MonoException *mono_ex = (MonoException*)exc;
 255                 if (!rethrow)
 256                         mono_ex->stack_trace = NULL;
 257         }
 258         mono_arch_handle_exception (&ctx, exc, FALSE);
 259         restore_context(&ctx);
 260
 261         g_assert_not_reached ();
 262 }
 263
 264 /*========================= End of Function ========================*/
 265
 266 /*------------------------------------------------------------------*/
 267 /*                                                                  */
 268 /* Name         - get_throw_exception_generic                       */
 269 /*                                                                  */
 270 /* Function     - Return a function pointer which can be used to    */
 271 /*                raise exceptions. The returned function has the   */
 272 /*                following signature:                              */
 273 /*                void (*func) (MonoException *exc); or,            */
 274 /*                void (*func) (char *exc_name);                    */
 275 /*                                                                  */
 276 /*------------------------------------------------------------------*/
 277
 278 static gpointer
 279 mono_arch_get_throw_exception_generic (int size, MonoTrampInfo **info,
 280                                 int corlib, gboolean rethrow, gboolean aot)
 281 {
 282         guint8 *code, *start;
 283         int alloc_size, pos, i;
 284
 285         code = start = mono_global_codeman_reserve(size);
 286
 287         s390_stmg (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 288         alloc_size = S390_ALIGN(S390_THROWSTACK_SIZE, S390_STACK_ALIGNMENT);
 289         s390_lgr  (code, s390_r14, STK_BASE);
 290         s390_aghi (code, STK_BASE, -alloc_size);
 291         s390_stg  (code, s390_r14, 0, STK_BASE, 0);
 292         s390_lgr  (code, s390_r3, s390_r2);
 293         if (corlib) {
 294                 s390_basr (code, s390_r13, 0);
 295                 s390_j    (code, 10);
 296                 s390_llong(code, mono_defaults.exception_class->image);
 297                 s390_llong(code, mono_exception_from_token);
 298                 s390_lg   (code, s390_r2, 0, s390_r13, 4);
 299                 s390_lg   (code, s390_r1, 0, s390_r13, 12);
 300                 s390_basr (code, s390_r14, s390_r1);
 301         }
 302
 303         /*------------------------------------------------------*/
 304         /* save the general registers on the stack              */
 305         /*------------------------------------------------------*/
 306         s390_stmg (code, s390_r0, s390_r13, STK_BASE, S390_THROWSTACK_INTREGS);
 307
 308         s390_lgr  (code, s390_r1, STK_BASE);
 309         s390_aghi (code, s390_r1, alloc_size);
 310         /*------------------------------------------------------*/
 311         /* save the return address in the parameter register    */
 312         /*------------------------------------------------------*/
 313         s390_lg   (code, s390_r3, 0, s390_r1, S390_RET_ADDR_OFFSET);
 314
 315         /*------------------------------------------------------*/
 316         /* save the floating point registers                    */
 317         /*------------------------------------------------------*/
 318         pos = S390_THROWSTACK_FLTREGS;
 319         for (i = 0; i < 16; ++i) {
 320                 s390_std (code, i, 0, STK_BASE, pos);
 321                 pos += sizeof (gdouble);
 322         }
 323         /*------------------------------------------------------*/
 324         /* save the access registers                            */
 325         /*------------------------------------------------------*/
 326         s390_stam (code, s390_r0, s390_r15, STK_BASE, S390_THROWSTACK_ACCREGS);
 327
 328         /*------------------------------------------------------*/
 329         /* call throw_exception (tkn, ip, sp, gr, fr, ar, re)   */
 330         /* - r2 already contains *exc                           */
 331         /*------------------------------------------------------*/
 332         s390_lgr  (code, s390_r4, s390_r1);        /* caller sp */
 333
 334         /*------------------------------------------------------*/
 335         /* pointer to the saved int regs                        */
 336         /*------------------------------------------------------*/
 337         s390_la   (code, s390_r5, 0, STK_BASE, S390_THROWSTACK_INTREGS);
 338         s390_la   (code, s390_r6, 0, STK_BASE, S390_THROWSTACK_FLTREGS);
 339         s390_la   (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_ACCREGS);
 340         s390_stg  (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_ACCPRM);
 341         s390_stfpc(code, STK_BASE, S390_THROWSTACK_FPCPRM+4);
 342         s390_lghi (code, s390_r7, rethrow);
 343         s390_stg  (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_RETHROW);
 344         s390_basr (code, s390_r13, 0);
 345         s390_j    (code, 6);
 346         s390_llong(code, throw_exception);
 347         s390_lg   (code, s390_r1, 0, s390_r13, 4);
 348         s390_basr (code, s390_r14, s390_r1);
 349         /* we should never reach this breakpoint */
 350         s390_break (code);
 351         g_assert ((code - start) < size);
 352         return start;
 353 }
 354
 355 /*========================= End of Function ========================*/
 356
 357 /*------------------------------------------------------------------*/
 358 /*                                                                  */
 359 /* Name         - arch_get_throw_exception                          */
 360 /*                                                                  */
 361 /* Function     - Return a function pointer which can be used to    */
 362 /*                raise exceptions. The returned function has the   */
 363 /*                following signature:                              */
 364 /*                void (*func) (MonoException *exc);                */
 365 /*                                                                  */
 366 /*------------------------------------------------------------------*/
 367
 368 gpointer
 369 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
 370 {
 371
 372         g_assert (!aot);
 373         if (info)
 374                 *info = NULL;
 375
 376         return (mono_arch_get_throw_exception_generic (SZ_THROW, info, FALSE, FALSE, aot));
 377 }
 378
 379 /*========================= End of Function ========================*/
 380
 381 /*------------------------------------------------------------------*/
 382 /*                                                                  */
 383 /* Name         - arch_get_rethrow_exception                        */
 384 /*                                                                  */
 385 /* Function     - Return a function pointer which can be used to    */
 386 /*                raise exceptions. The returned function has the   */
 387 /*                following signature:                              */
 388 /*                void (*func) (MonoException *exc);                */
 389 /*                                                                  */
 390 /*------------------------------------------------------------------*/
 391
 392 gpointer
 393 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
 394 {
 395         g_assert (!aot);
 396         if (info)
 397                 *info = NULL;
 398
 399         return (mono_arch_get_throw_exception_generic (SZ_THROW, info, FALSE, FALSE, aot));
 400 }
 401
 402 /*========================= End of Function ========================*/
 403
 404 /*------------------------------------------------------------------*/
 405 /*                                                                  */
 406 /* Name         - arch_get_corlib_exception                         */
 407 /*                                                                  */
 408 /* Function     - Return a function pointer which can be used to    */
 409 /*                raise corlib exceptions. The return function has  */
 410 /*                the following signature:                          */
 411 /*                void (*func) (guint32 token, guint32 offset)      */
 412 /*                                                                  */
 413 /*------------------------------------------------------------------*/
 414
 415 gpointer
 416 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
 417 {
 418         g_assert (!aot);
 419         if (info)
 420                 *info = NULL;
 421
 422         return (mono_arch_get_throw_exception_generic (SZ_THROW, info, TRUE, FALSE, aot));
 423 }
 424
 425 /*========================= End of Function ========================*/
 426
 427 /*------------------------------------------------------------------*/
 428 /*                                                                  */
 429 /* Name         - mono_arch_find_jit_info                           */
 430 /*                                                                  */
 431 /* Function     - See exceptions-amd64.c for docs.                      */
 432 /*                                                                  */
 433 /*------------------------------------------------------------------*/
 434
 435 gboolean
 436 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
 437                                                          MonoJitInfo *ji, MonoContext *ctx,
 438                                                          MonoContext *new_ctx, MonoLMF **lmf,
 439                                                          StackFrameInfo *frame)
 440 {
 441         gpointer ip = (gpointer) MONO_CONTEXT_GET_IP (ctx);
 442         MonoS390StackFrame *sframe;
 443
 444         memset (frame, 0, sizeof (StackFrameInfo));
 445         frame->ji = ji;
 446         frame->managed = FALSE;
 447
 448         *new_ctx = *ctx;
 449
 450         if (ji != NULL) {
 451                 gint64 address;
 452
 453                 frame->type = FRAME_TYPE_MANAGED;
 454
 455                 if (!ji->method->wrapper_type || ji->method->wrapper_type == MONO_WRAPPER_DYNAMIC_METHOD)
 456                         frame->managed = TRUE;
 457
 458                 if (*lmf && (MONO_CONTEXT_GET_SP (ctx) >= (gpointer)(*lmf)->ebp)) {
 459                         /* remove any unused lmf */
 460                         *lmf = (*lmf)->previous_lmf;
 461                 }
 462
 463                 address = (char *)ip - (char *)ji->code_start;
 464
 465                 sframe = (MonoS390StackFrame *) MONO_CONTEXT_GET_SP (ctx);
 466                 MONO_CONTEXT_SET_BP (new_ctx, sframe->prev);
 467                 sframe = (MonoS390StackFrame *) sframe->prev;
 468                 MONO_CONTEXT_SET_IP (new_ctx, (guint8*)sframe->return_address - 2);
 469                 memcpy (&new_ctx->uc_mcontext.gregs[6], sframe->regs, (8*sizeof(gint64)));
 470                 return TRUE;
 471
 472         } else if (*lmf) {
 473                 if (!(*lmf)->method)
 474                         return FALSE;
 475
 476                 ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL);
 477                 if (!ji) {
 478                         // FIXME: This can happen with multiple appdomains (bug #444383)
 479                         return FALSE;
 480                 }
 481
 482                 frame->ji = ji;
 483                 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
 484
 485                 memcpy(new_ctx->uc_mcontext.gregs, (*lmf)->gregs, sizeof((*lmf)->gregs));
 486                 memcpy(new_ctx->uc_mcontext.fpregs.fprs, (*lmf)->fregs, sizeof((*lmf)->fregs));
 487
 488                 MONO_CONTEXT_SET_BP (new_ctx, (*lmf)->ebp);
 489                 MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip - 2);
 490                 *lmf = (*lmf)->previous_lmf;
 491
 492                 return TRUE;
 493         }
 494
 495         return FALSE;
 496 }
 497
 498 /*========================= End of Function ========================*/
 499
 500 /*------------------------------------------------------------------*/
 501 /*                                                                  */
 502 /* Name         - mono_arch_handle_exception                        */
 503 /*                                                                  */
 504 /* Function     - Handle an exception raised by the JIT code.       */
 505 /*                                                                  */
 506 /* Parameters   - ctx       - Saved processor state                 */
 507 /*                obj       - The exception object                  */
 508 /*                test_only - Only test if the exception is caught, */
 509 /*                            but don't call handlers               */
 510 /*                                                                  */
 511 /*------------------------------------------------------------------*/
 512
 513 gboolean
 514 mono_arch_handle_exception (void *uc, gpointer obj, gboolean test_only)
 515 {
 516         return mono_handle_exception (uc, obj, mono_arch_ip_from_context(uc), test_only);
 517 }
 518
 519 /*========================= End of Function ========================*/
 520
 521 /*------------------------------------------------------------------*/
 522 /*                                                                  */
 523 /* Name         - mono_arch_sigctx_to_monoctx.                      */
 524 /*                                                                  */
 525 /* Function     - Called from the signal handler to convert signal  */
 526 /*                context to MonoContext.                           */
 527 /*                                                                  */
 528 /*------------------------------------------------------------------*/
 529
 530 void
 531 mono_arch_sigctx_to_monoctx (void *ctx, MonoContext *mctx)
 532 {
 533         memcpy (mctx, ctx, sizeof(MonoContext));
 534 }
 535
 536 /*========================= End of Function ========================*/
 537
 538 /*------------------------------------------------------------------*/
 539 /*                                                                  */
 540 /* Name         - mono_arch_monoctx_to_sigctx.                      */
 541 /*                                                                  */
 542 /* Function     - Convert MonoContext structure to signal context.  */
 543 /*                                                                  */
 544 /*------------------------------------------------------------------*/
 545
 546 void
 547 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *ctx)
 548 {
 549         memcpy (ctx, mctx, sizeof(MonoContext));
 550 }
 551
 552 /*========================= End of Function ========================*/
 553
 554 /*------------------------------------------------------------------*/
 555 /*                                                                  */
 556 /* Name         - mono_arch_ip_from_context                         */
 557 /*                                                                  */
 558 /* Function     - Return the instruction pointer from the context.  */
 559 /*                                                                  */
 560 /* Parameters   - sigctx    - Saved processor state                 */
 561 /*                                                                  */
 562 /*------------------------------------------------------------------*/
 563
 564 gpointer
 565 mono_arch_ip_from_context (void *sigctx)
 566 {
 567         return ((gpointer) MONO_CONTEXT_GET_IP(((MonoContext *) sigctx)));
 568 }
 569
 570
 571 /*========================= End of Function ========================*/
 572
 573 /*------------------------------------------------------------------*/
 574 /*                                                                  */
 575 /* Name         - mono_arch_get_restore_context                    */
 576 /*                                                                  */
 577 /* Function     - Return the address of the routine that will rest- */
 578 /*                ore the context.                                  */
 579 /*                                                                  */
 580 /*------------------------------------------------------------------*/
 581
 582 gpointer
 583 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
 584 {
 585         g_assert (!aot);
 586         if (info)
 587                 *info = NULL;
 588
 589         return setcontext;
 590 }
 591
 592 /*========================= End of Function ========================*/
 593
 594 /*------------------------------------------------------------------*/
 595 /*                                                                  */
 596 /* Name         - mono_arch_is_int_overflow                         */
 597 /*                                                                  */
 598 /* Function     - Inspect the code that raised the SIGFPE signal    */
 599 /*                to see if the DivideByZero or Arithmetic exception*/
 600 /*                should be raised.                                 */
 601 /*                                                                  */
 602 /*------------------------------------------------------------------*/
 603
 604 gboolean
 605 mono_arch_is_int_overflow (void *uc, void *info)
 606 {
 607         MonoContext *ctx;
 608         guint8      *code;
 609         guint64     *operand;
 610         gboolean    arithExc = TRUE;
 611         gint        regNo,
 612                     idxNo,
 613                     offset;
 614
 615         ctx  = (MonoContext *) uc;
 616         code =  (guint8 *) ((siginfo_t *)info)->si_addr;
 617         /*----------------------------------------------------------*/
 618         /* Divide operations are the only ones that will give the   */
 619         /* divide by zero exception so just check for these ops.    */
 620         /*----------------------------------------------------------*/
 621         switch (code[0]) {
 622                 case 0x1d :             /* Divide Register          */
 623                         regNo = code[1] & 0x0f;
 624                         if (ctx->uc_mcontext.gregs[regNo] == 0)
 625                                 arithExc = FALSE;
 626                 break;
 627                 case 0x5d :             /* Divide                   */
 628                         regNo   = (code[2] & 0xf0 >> 8);
 629                         idxNo   = (code[1] & 0x0f);
 630                         offset  = *((guint16 *) code+2) & 0x0fff;
 631                         operand = (guint64*)(ctx->uc_mcontext.gregs[regNo] + offset);
 632                         if (idxNo != 0)
 633                                 operand += ctx->uc_mcontext.gregs[idxNo];
 634                         if (*operand == 0)
 635                                 arithExc = FALSE;
 636                 break;
 637                 case 0xb9 :             /* DL[GR] or DS[GR]         */
 638                         if ((code[1] == 0x97) || (code[1] == 0x87) ||
 639                             (code[1] == 0x0d) || (code[1] == 0x1d)) {
 640                                 regNo = (code[3] & 0x0f);
 641                                 if (ctx->uc_mcontext.gregs[regNo] == 0)
 642                                         arithExc = FALSE;
 643                         }
 644                 break;
 645                 case 0xe3 :             /* DL[G] | DS[G]            */
 646                         if ((code[5] == 0x97) || (code[5] == 0x87) ||
 647                             (code[5] == 0x0d) || (code[5] == 0x1d)) {
 648                                 regNo   = (code[2] & 0xf0 >> 8);
 649                                 idxNo   = (code[1] & 0x0f);
 650                                 offset  = (code[2] & 0x0f << 8) +
 651                                           code[3] + (code[4] << 12);
 652                                 operand = (guint64*)(ctx->uc_mcontext.gregs[regNo] + offset);
 653                                 if (idxNo != 0)
 654                                         operand += ctx->uc_mcontext.gregs[idxNo];
 655                                 if (*operand == 0)
 656                                         arithExc = FALSE;
 657                         }
 658                 break;
 659                 default:
 660                         arithExc = TRUE;
 661         }
 662         ctx->uc_mcontext.psw.addr = (guint64)code;
 663         return (arithExc);
 664 }
 665
 666 /*========================= End of Function ========================*/