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