mono/mini/exceptions-s390.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(gulong)))
  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(gulong)))
  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/s390/s390-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-s390.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
  70 /*========================= End of Prototypes ======================*/
  71
  72 /*------------------------------------------------------------------*/
  73 /*                 G l o b a l   V a r i a b l e s                  */
  74 /*------------------------------------------------------------------*/
  75
  76 /*====================== End of Global Variables ===================*/
  77
  78 /*------------------------------------------------------------------*/
  79 /*                                                                  */
  80 /* Name         - mono_arch_get_call_filter                         */
  81 /*                                                                  */
  82 /* Function     - Return a pointer to a method which calls an       */
  83 /*                exception filter. We also use this function to    */
  84 /*                call finally handlers (we pass NULL as @exc       */
  85 /*                object in this case).                             */
  86 /*                                                                  */
  87 /*------------------------------------------------------------------*/
  88
  89 gpointer
  90 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
  91 {
  92         static guint8 *start;
  93         static int inited = 0;
  94         guint8 *code;
  95         int alloc_size, pos, i;
  96
  97         g_assert (!aot);
  98         if (info)
  99                 *info = NULL;
 100
 101         if (inited)
 102                 return start;
 103
 104         inited = 1;
 105         /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */
 106         code = start = mono_global_codeman_reserve (512);
 107
 108         s390_stm (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 109         s390_lr  (code, s390_r14, STK_BASE);
 110         alloc_size = S390_ALIGN(S390_CALLFILTER_SIZE, S390_STACK_ALIGNMENT);
 111         s390_ahi (code, STK_BASE, -alloc_size);
 112         s390_st  (code, s390_r14, 0, STK_BASE, 0);
 113
 114         /*------------------------------------------------------*/
 115         /* save general registers on stack                      */
 116         /*------------------------------------------------------*/
 117         s390_stm (code, s390_r0, s390_r13, STK_BASE, S390_CALLFILTER_INTREGS);
 118
 119         /*------------------------------------------------------*/
 120         /* save floating point registers on stack               */
 121         /*------------------------------------------------------*/
 122 //      pos = S390_CALLFILTER_FLTREGS;
 123 //      for (i = 0; i < 16; ++i) {
 124 //              s390_std (code, i, 0, STK_BASE, pos);
 125 //              pos += sizeof (gdouble);
 126 //      }
 127
 128         /*------------------------------------------------------*/
 129         /* save access registers on stack                       */
 130         /*------------------------------------------------------*/
 131 //      s390_stam (code, s390_a0, s390_a15, STK_BASE, S390_CALLFILTER_ACCREGS);
 132
 133         /*------------------------------------------------------*/
 134         /* Get A(Context)                                       */
 135         /*------------------------------------------------------*/
 136         s390_lr   (code, s390_r13, s390_r2);
 137
 138         /*------------------------------------------------------*/
 139         /* Get A(Handler Entry Point)                           */
 140         /*------------------------------------------------------*/
 141         s390_lr   (code, s390_r0, s390_r3);
 142
 143         /*------------------------------------------------------*/
 144         /* Set parameter register with Exception                */
 145         /*------------------------------------------------------*/
 146         s390_lr   (code, s390_r2, s390_r4);
 147
 148         /*------------------------------------------------------*/
 149         /* Load all registers with values from the context      */
 150         /*------------------------------------------------------*/
 151         s390_lm   (code, s390_r3, s390_r12, s390_r13,
 152                    G_STRUCT_OFFSET(MonoContext, uc_mcontext.gregs[3]));
 153         pos = G_STRUCT_OFFSET(MonoContext, uc_mcontext.fpregs.fprs[0]);
 154         for (i = 0; i < 16; ++i) {
 155                 s390_ld  (code, i, 0, s390_r13, pos);
 156                 pos += sizeof(gdouble);
 157         }
 158
 159         /*------------------------------------------------------*/
 160         /* Point at the copied stack frame and call the filter  */
 161         /*------------------------------------------------------*/
 162         s390_lr   (code, s390_r1, s390_r0);
 163         s390_basr (code, s390_r14, s390_r1);
 164
 165         /*------------------------------------------------------*/
 166         /* Save return value                                    */
 167         /*------------------------------------------------------*/
 168         s390_lr   (code, s390_r14, s390_r2);
 169
 170         /*------------------------------------------------------*/
 171         /* Restore all the regs from the stack                  */
 172         /*------------------------------------------------------*/
 173         s390_lm (code, s390_r0, s390_r13, STK_BASE, S390_CALLFILTER_INTREGS);
 174 //      pos = S390_CALLFILTER_FLTREGS;
 175 //      for (i = 0; i < 16; ++i) {
 176 //              s390_ld (code, i, 0, STK_BASE, pos);
 177 //              pos += sizeof (gdouble);
 178 //      }
 179
 180         s390_lr   (code, s390_r2, s390_r14);
 181 //      s390_lam  (code, s390_a0, s390_a15, STK_BASE, S390_CALLFILTER_ACCREGS);
 182         s390_ahi  (code, s390_r15, alloc_size);
 183         s390_lm   (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 184         s390_br   (code, s390_r14);
 185
 186         g_assert ((code - start) < SZ_THROW);
 187         return start;
 188 }
 189
 190 /*========================= End of Function ========================*/
 191
 192 /*------------------------------------------------------------------*/
 193 /*                                                                  */
 194 /* Name         - throw_exception.                                  */
 195 /*                                                                  */
 196 /* Function     - Raise an exception based on the parameters passed.*/
 197 /*                                                                  */
 198 /*------------------------------------------------------------------*/
 199
 200 static void
 201 throw_exception (MonoObject *exc, unsigned long ip, unsigned long sp,
 202                  gulong *int_regs, gdouble *fp_regs, gulong *acc_regs,
 203                  guint fpc, gboolean rethrow)
 204 {
 205         MonoContext ctx;
 206         int iReg;
 207
 208         memset(&ctx, 0, sizeof(ctx));
 209
 210         getcontext(&ctx);
 211
 212         /* adjust eip so that it point into the call instruction */
 213         ip -= 6;
 214
 215         for (iReg = 0; iReg < 16; iReg++) {
 216                 ctx.uc_mcontext.gregs[iReg]         = int_regs[iReg];
 217                 ctx.uc_mcontext.fpregs.fprs[iReg].d = fp_regs[iReg];
 218                 ctx.uc_mcontext.aregs[iReg]         = acc_regs[iReg];
 219         }
 220
 221         ctx.uc_mcontext.fpregs.fpc = fpc;
 222
 223         MONO_CONTEXT_SET_BP (&ctx, sp);
 224         MONO_CONTEXT_SET_IP (&ctx, ip);
 225
 226         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 227                 MonoException *mono_ex = (MonoException*)exc;
 228                 if (!rethrow)
 229                         mono_ex->stack_trace = NULL;
 230         }
 231         mono_arch_handle_exception (&ctx, exc);
 232         setcontext(&ctx);
 233
 234         g_assert_not_reached ();
 235 }
 236
 237 /*========================= End of Function ========================*/
 238
 239 /*------------------------------------------------------------------*/
 240 /*                                                                  */
 241 /* Name         - get_throw_exception_generic                       */
 242 /*                                                                  */
 243 /* Function     - Return a function pointer which can be used to    */
 244 /*                raise exceptions. The returned function has the   */
 245 /*                following signature:                              */
 246 /*                void (*func) (MonoException *exc); or,            */
 247 /*                void (*func) (char *exc_name);                    */
 248 /*                                                                  */
 249 /*------------------------------------------------------------------*/
 250
 251 static gpointer
 252 get_throw_exception_generic (guint8 *start, int size,
 253                              int by_name, gboolean rethrow)
 254 {
 255         guint8 *code;
 256         int alloc_size, pos, i, offset;
 257
 258         code = start;
 259
 260         s390_stm (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 261         alloc_size = S390_ALIGN(S390_THROWSTACK_SIZE, S390_STACK_ALIGNMENT);
 262         s390_lr   (code, s390_r14, STK_BASE);
 263         s390_ahi  (code, STK_BASE, -alloc_size);
 264         s390_st   (code, s390_r14, 0, STK_BASE, 0);
 265         if (by_name) {
 266                 s390_lr   (code, s390_r4, s390_r2);
 267                 s390_bras (code, s390_r13, 6);
 268                 s390_word (code, mono_defaults.corlib);
 269                 s390_word (code, "System");
 270                 s390_l    (code, s390_r2, 0, s390_r13, 0);
 271                 s390_l    (code, s390_r3, 0, s390_r13, 4);
 272                 offset = (guint32) S390_RELATIVE(mono_exception_from_name, code);
 273                 s390_brasl(code, s390_r14, offset);
 274         }
 275         /*------------------------------------------------------*/
 276         /* save the general registers on the stack              */
 277         /*------------------------------------------------------*/
 278         s390_stm (code, s390_r0, s390_r13, STK_BASE, S390_THROWSTACK_INTREGS);
 279
 280         s390_lr  (code, s390_r1, STK_BASE);
 281         s390_ahi (code, s390_r1, alloc_size);
 282         /*------------------------------------------------------*/
 283         /* save the return address in the parameter register    */
 284         /*------------------------------------------------------*/
 285         s390_l   (code, s390_r3, 0, s390_r1, S390_RET_ADDR_OFFSET);
 286
 287         /*------------------------------------------------------*/
 288         /* save the floating point registers                    */
 289         /*------------------------------------------------------*/
 290         pos = S390_THROWSTACK_FLTREGS;
 291         for (i = 0; i < 16; ++i) {
 292                 s390_std (code, i, 0,STK_BASE, pos);
 293                 pos += sizeof (gdouble);
 294         }
 295         /*------------------------------------------------------*/
 296         /* save the access registers                            */
 297         /*------------------------------------------------------*/
 298         s390_stam (code, s390_r0, s390_r15, STK_BASE, S390_THROWSTACK_ACCREGS);
 299
 300         /*------------------------------------------------------*/
 301         /* call throw_exception (exc, ip, sp, gr, fr, ar)       */
 302         /* exc is already in place in r2                        */
 303         /*------------------------------------------------------*/
 304         s390_lr   (code, s390_r4, s390_r1);        /* caller sp */
 305         /*------------------------------------------------------*/
 306         /* pointer to the saved int regs                        */
 307         /*------------------------------------------------------*/
 308         s390_la   (code, s390_r5, 0, STK_BASE, S390_THROWSTACK_INTREGS);
 309         s390_la   (code, s390_r6, 0, STK_BASE, S390_THROWSTACK_FLTREGS);
 310         s390_la   (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_ACCREGS);
 311         s390_st   (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_ACCPRM);
 312         s390_stfpc(code, STK_BASE, S390_THROWSTACK_FPCPRM);
 313         s390_lhi  (code, s390_r7, rethrow);
 314         s390_st   (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_RETHROW);
 315         offset = (guint32) S390_RELATIVE(throw_exception, code);
 316         s390_brasl(code, s390_r14, offset);
 317         /* we should never reach this breakpoint */
 318         s390_break (code);
 319         g_assert ((code - start) < size);
 320         return start;
 321 }
 322
 323 /*========================= End of Function ========================*/
 324
 325 /*------------------------------------------------------------------*/
 326 /*                                                                  */
 327 /* Name         - arch_get_throw_exception                          */
 328 /*                                                                  */
 329 /* Function     - Return a function pointer which can be used to    */
 330 /*                raise exceptions. The returned function has the   */
 331 /*                following signature:                              */
 332 /*                void (*func) (MonoException *exc);                */
 333 /*                                                                  */
 334 /*------------------------------------------------------------------*/
 335
 336 gpointer
 337 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
 338 {
 339         static guint8 *start;
 340         static int inited = 0;
 341
 342         g_assert (!aot);
 343         if (info)
 344                 *info = NULL;
 345
 346         if (inited)
 347                 return start;
 348         start = mono_global_codeman_reserve (SZ_THROW);
 349         get_throw_exception_generic (start, SZ_THROW, FALSE, FALSE);
 350         inited = 1;
 351         return start;
 352 }
 353
 354 /*========================= End of Function ========================*/
 355
 356 /*------------------------------------------------------------------*/
 357 /*                                                                  */
 358 /* Name         - arch_get_rethrow_exception                        */
 359 /*                                                                  */
 360 /* Function     - Return a function pointer which can be used to    */
 361 /*                raise exceptions. The returned function has the   */
 362 /*                following signature:                              */
 363 /*                void (*func) (MonoException *exc);                */
 364 /*                                                                  */
 365 /*------------------------------------------------------------------*/
 366
 367 gpointer
 368 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
 369 {
 370         static guint8 *start;
 371         static int inited = 0;
 372
 373         g_assert (!aot);
 374         if (info)
 375                 *info = NULL;
 376
 377         if (inited)
 378                 return start;
 379         start = mono_global_codeman_reserve (SZ_THROW);
 380         get_throw_exception_generic (start, SZ_THROW, FALSE, TRUE);
 381         inited = 1;
 382         return start;
 383 }
 384
 385 /*========================= End of Function ========================*/
 386
 387 /*------------------------------------------------------------------*/
 388 /*                                                                  */
 389 /* Name         - arch_get_throw_exception_by_name                  */
 390 /*                                                                  */
 391 /* Function     - Return a function pointer which can be used to    */
 392 /*                raise corlib exceptions. The return function has  */
 393 /*                the following signature:                          */
 394 /*                void (*func) (char *exc_name);                    */
 395 /*                                                                  */
 396 /*------------------------------------------------------------------*/
 397
 398 gpointer
 399 mono_arch_get_throw_exception_by_name (void)
 400 {
 401         static guint8 *start;
 402         static int inited = 0;
 403
 404         if (inited)
 405                 return start;
 406         start = mono_global_codeman_reserve (SZ_THROW);
 407         get_throw_exception_generic (start, SZ_THROW, TRUE, FALSE);
 408         inited = 1;
 409         return start;
 410 }
 411
 412 /*========================= End of Function ========================*/
 413
 414 /*------------------------------------------------------------------*/
 415 /*                                                                  */
 416 /* Name         - mono_arch_find_jit_info                           */
 417 /*                                                                  */
 418 /* Function     - See exceptions-amd64.c for docs.                      */
 419 /*                                                                  */
 420 /*------------------------------------------------------------------*/
 421
 422 gboolean
 423 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
 424                                                          MonoJitInfo *ji, MonoContext *ctx,
 425                                                          MonoContext *new_ctx, MonoLMF **lmf,
 426                                                          mgreg_t **save_locations,
 427                                                          StackFrameInfo *frame)
 428 {
 429         gpointer ip = MONO_CONTEXT_GET_IP (ctx);
 430         MonoS390StackFrame *sframe;
 431
 432         memset (frame, 0, sizeof (StackFrameInfo));
 433         frame->ji = ji;
 434
 435         *new_ctx = *ctx;
 436
 437         if (ji != NULL) {
 438                 gint32 address;
 439
 440                 frame->type = FRAME_TYPE_MANAGED;
 441
 442                 if (*lmf && (MONO_CONTEXT_GET_SP (ctx) >= (gpointer)(*lmf)->ebp)) {
 443                         /* remove any unused lmf */
 444                         *lmf = (*lmf)->previous_lmf;
 445                 }
 446
 447                 address = (char *)ip - (char *)ji->code_start;
 448
 449                 sframe = (MonoS390StackFrame *) MONO_CONTEXT_GET_SP (ctx);
 450                 MONO_CONTEXT_SET_BP (new_ctx, sframe->prev);
 451                 sframe = (MonoS390StackFrame *) sframe->prev;
 452                 MONO_CONTEXT_SET_IP (new_ctx, (guint8*)sframe->return_address - 2);
 453                 memcpy (&new_ctx->uc_mcontext.gregs[6], sframe->regs, (8*sizeof(gint32)));
 454                 return TRUE;
 455         } else if (*lmf) {
 456                 if (!(*lmf)->method)
 457                         return FALSE;
 458
 459                 ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL);
 460                 if (!ji) {
 461                         // FIXME: This can happen with multiple appdomains (bug #444383)
 462                         return FALSE;
 463                 }
 464
 465                 frame->ji = ji;
 466                 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
 467
 468                 memcpy(new_ctx->uc_mcontext.gregs, (*lmf)->gregs, sizeof((*lmf)->gregs));
 469                 memcpy(new_ctx->uc_mcontext.fpregs.fprs, (*lmf)->fregs, sizeof((*lmf)->fregs));
 470
 471                 MONO_CONTEXT_SET_BP (new_ctx, (*lmf)->ebp);
 472                 MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip - 2);
 473                 *lmf = (*lmf)->previous_lmf;
 474
 475                 return TRUE;
 476         }
 477
 478         return FALSE;
 479 }
 480
 481 /*========================= End of Function ========================*/
 482
 483 /*------------------------------------------------------------------*/
 484 /*                                                                  */
 485 /* Name         - mono_arch_handle_exception                        */
 486 /*                                                                  */
 487 /* Function     - Handle an exception raised by the JIT code.       */
 488 /*                                                                  */
 489 /* Parameters   - ctx       - Saved processor state                 */
 490 /*                obj       - The exception object                  */
 491 /*                                                                  */
 492 /*------------------------------------------------------------------*/
 493
 494 gboolean
 495 mono_arch_handle_exception (void *uc, gpointer obj)
 496 {
 497         return mono_handle_exception (uc, obj);
 498 }
 499
 500 /*========================= End of Function ========================*/
 501
 502 /*------------------------------------------------------------------*/
 503 /*                                                                  */
 504 /* Name         - mono_arch_ip_from_context                         */
 505 /*                                                                  */
 506 /* Function     - Return the instruction pointer from the context.  */
 507 /*                                                                  */
 508 /* Parameters   - sigctx    - Saved processor state                 */
 509 /*                                                                  */
 510 /*------------------------------------------------------------------*/
 511
 512 gpointer
 513 mono_arch_ip_from_context (void *sigctx)
 514 {
 515         return context_get_ip (sigctx);
 516 }
 517
 518
 519 /*========================= End of Function ========================*/
 520
 521 /*------------------------------------------------------------------*/
 522 /*                                                                  */
 523 /* Name         - mono_arch_get_restore_context                    */
 524 /*                                                                  */
 525 /* Function     - Return the address of the routine that will rest- */
 526 /*                ore the context.                                  */
 527 /*                                                                  */
 528 /*------------------------------------------------------------------*/
 529
 530 gpointer
 531 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
 532 {
 533         g_assert (!aot);
 534         if (info)
 535                 *info = NULL;
 536
 537         return setcontext;
 538 }
 539
 540
 541 /*========================= End of Function ========================*/
 542
 543 /*------------------------------------------------------------------*/
 544 /*                                                                  */
 545 /* Name         - mono_arch_is_int_overflow                         */
 546 /*                                                                  */
 547 /* Function     - Inspect the code that raised the SIGFPE signal    */
 548 /*                to see if the DivideByZero or Arithmetic exception*/
 549 /*                should be raised.                                 */
 550 /*                                                                  */
 551 /*------------------------------------------------------------------*/
 552
 553 gboolean
 554 mono_arch_is_int_overflow (void *uc, void *info)
 555 {
 556         MonoContext *ctx;
 557         guint8      *code;
 558         guint32     *operand;
 559         gboolean    arithExc = TRUE;
 560         gint        regNo,
 561                     offset;
 562
 563         ctx  = (MonoContext *) uc;
 564         code =  (guint8 *) ((siginfo_t *)info)->si_addr;
 565         /*----------------------------------------------------------*/
 566         /* Divide operations are the only ones that will give the   */
 567         /* divide by zero exception so just check for these ops.    */
 568         /*----------------------------------------------------------*/
 569         switch (code[0]) {
 570                 case 0x1d :             /* Divide Register          */
 571                         regNo = code[1] & 0x0f;
 572                         if (ctx->uc_mcontext.gregs[regNo] == 0)
 573                                 arithExc = FALSE;
 574                 break;
 575                 case 0x5d :             /* Divide                   */
 576                         regNo   = (code[2] & 0xf0 >> 8);
 577                         offset  = *((guint16 *) code+2) & 0x0fff;
 578                         operand = (guint32*)(ctx->uc_mcontext.gregs[regNo] + offset);
 579                         if (*operand == 0)
 580                                 arithExc = FALSE;
 581                 break;
 582                 case 0xb9 :             /* Divide logical Register? */
 583                         if (code[1] == 0x97) {
 584                                 regNo = (code[2] & 0xf0 >> 8);
 585                                 if (ctx->uc_mcontext.gregs[regNo] == 0)
 586                                         arithExc = FALSE;
 587                         }
 588                 break;
 589                 case 0xe3 :             /* Divide logical?          */
 590                         if (code[1] == 0x97) {
 591                                 regNo   = (code[2] & 0xf0 >> 8);
 592                                 offset  = *((guint32 *) code+1) & 0x000fffff;
 593                                 operand = (guint32*)(ctx->uc_mcontext.gregs[regNo] + offset);
 594                                 if (*operand == 0)
 595                                         arithExc = FALSE;
 596                         }
 597                 break;
 598                 default:
 599                         arithExc = TRUE;
 600         }
 601         ctx->uc_mcontext.psw.addr = (guint32)code;
 602         return (arithExc);
 603 }
 604
 605 /*========================= End of Function ========================*/