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 static void throw_exception (MonoObject *, unsigned long, unsigned long,
  70                  gulong *, gdouble *, gint32 *, guint, gboolean);
  71 static gpointer mono_arch_get_throw_exception_generic (int, MonoTrampInfo **,
  72                                 int, gboolean, gboolean);
  73 static void handle_signal_exception (gpointer);
  74
  75 /*========================= End of Prototypes ======================*/
  76
  77 /*------------------------------------------------------------------*/
  78 /*                 G l o b a l   V a r i a b l e s                  */
  79 /*------------------------------------------------------------------*/
  80
  81 typedef enum {
  82         by_none,
  83         by_token
  84 } throwType;
  85
  86 /*====================== End of Global Variables ===================*/
  87
  88 /*------------------------------------------------------------------*/
  89 /*                                                                  */
  90 /* Name         - mono_arch_get_call_filter                         */
  91 /*                                                                  */
  92 /* Function     - Return a pointer to a method which calls an       */
  93 /*                exception filter. We also use this function to    */
  94 /*                call finally handlers (we pass NULL as @exc       */
  95 /*                object in this case).                             */
  96 /*                                                                  */
  97 /*------------------------------------------------------------------*/
  98
  99 gpointer
 100 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
 101 {
 102         static guint8 *start;
 103         static int inited = 0;
 104         guint8 *code;
 105         int alloc_size, pos, i;
 106         GSList *unwind_ops = NULL;
 107         MonoJumpInfo *ji = NULL;
 108
 109         g_assert (!aot);
 110
 111         if (inited)
 112                 return start;
 113
 114         inited = 1;
 115         /* call_filter (MonoContext *ctx, unsigned long eip, gpointer exc) */
 116         code = start = mono_global_codeman_reserve (512);
 117
 118         s390_stmg (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 119         s390_lgr  (code, s390_r14, STK_BASE);
 120         alloc_size = S390_ALIGN(S390_CALLFILTER_SIZE, S390_STACK_ALIGNMENT);
 121         s390_aghi (code, STK_BASE, -alloc_size);
 122         s390_stg  (code, s390_r14, 0, STK_BASE, 0);
 123
 124         /*------------------------------------------------------*/
 125         /* save general registers on stack                      */
 126         /*------------------------------------------------------*/
 127         s390_stmg (code, s390_r0, STK_BASE, STK_BASE, S390_CALLFILTER_INTREGS);
 128
 129         /*------------------------------------------------------*/
 130         /* save floating point registers on stack               */
 131         /*------------------------------------------------------*/
 132         pos = S390_CALLFILTER_FLTREGS;
 133         for (i = 0; i < 16; ++i) {
 134                 s390_std (code, i, 0, STK_BASE, pos);
 135                 pos += sizeof (gdouble);
 136         }
 137
 138         /*------------------------------------------------------*/
 139         /* save access registers on stack                       */
 140         /*------------------------------------------------------*/
 141         s390_stam (code, s390_a0, s390_a15, STK_BASE, S390_CALLFILTER_ACCREGS);
 142
 143         /*------------------------------------------------------*/
 144         /* Get A(Context)                                       */
 145         /*------------------------------------------------------*/
 146         s390_lgr  (code, s390_r13, s390_r2);
 147
 148         /*------------------------------------------------------*/
 149         /* Get A(Handler Entry Point)                           */
 150         /*------------------------------------------------------*/
 151         s390_lgr  (code, s390_r0, s390_r3);
 152
 153         /*------------------------------------------------------*/
 154         /* Set parameter register with Exception                */
 155         /*------------------------------------------------------*/
 156         s390_lgr  (code, s390_r2, s390_r4);
 157
 158         /*------------------------------------------------------*/
 159         /* Load all registers with values from the context      */
 160         /*------------------------------------------------------*/
 161         s390_lmg  (code, s390_r3, s390_r12, s390_r13,
 162                    G_STRUCT_OFFSET(MonoContext, uc_mcontext.gregs[3]));
 163         pos = G_STRUCT_OFFSET(MonoContext, uc_mcontext.fpregs.fprs[0]);
 164         for (i = 0; i < 16; ++i) {
 165                 s390_ld  (code, i, 0, s390_r13, pos);
 166                 pos += sizeof(gdouble);
 167         }
 168
 169 #if 0
 170         /*------------------------------------------------------*/
 171         /* We need to preserve current SP before calling filter */
 172         /* with SP from the context                             */
 173         /*------------------------------------------------------*/
 174         s390_lgr  (code, s390_r14, STK_BASE);
 175         s390_lg   (code, STK_BASE, 0, s390_r13,
 176                    G_STRUCT_OFFSET(MonoContext, uc_mcontext.gregs[15]));
 177         s390_lgr  (code, s390_r13, s390_r14);
 178 #endif
 179
 180         /*------------------------------------------------------*/
 181         /* Go call filter                                       */
 182         /*------------------------------------------------------*/
 183         s390_lgr  (code, s390_r1, s390_r0);
 184         s390_basr (code, s390_r14, s390_r1);
 185
 186         /*------------------------------------------------------*/
 187         /* Save return value                                    */
 188         /*------------------------------------------------------*/
 189         s390_lgr  (code, s390_r14, s390_r2);
 190
 191 #if 0
 192         /*------------------------------------------------------*/
 193         /* Reload our stack register with value saved in context*/
 194         /*------------------------------------------------------*/
 195         s390_lgr  (code, STK_BASE, s390_r13);
 196 #endif
 197
 198         /*------------------------------------------------------*/
 199         /* Restore all the regs from the stack                  */
 200         /*------------------------------------------------------*/
 201         s390_lmg  (code, s390_r0, s390_r13, STK_BASE, S390_CALLFILTER_INTREGS);
 202         pos = S390_CALLFILTER_FLTREGS;
 203         for (i = 0; i < 16; ++i) {
 204                 s390_ld (code, i, 0, STK_BASE, pos);
 205                 pos += sizeof (gdouble);
 206         }
 207
 208         s390_lgr  (code, s390_r2, s390_r14);
 209         s390_lam  (code, s390_a0, s390_a15, STK_BASE, S390_CALLFILTER_ACCREGS);
 210         s390_aghi (code, s390_r15, alloc_size);
 211         s390_lmg  (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 212         s390_br   (code, s390_r14);
 213
 214         g_assert ((code - start) < SZ_THROW);
 215
 216         mono_arch_flush_icache(start, code - start);
 217         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
 218
 219         if (info)
 220                 *info = mono_tramp_info_create ("call_filter",
 221                                                 start, code - start, ji,
 222                                                 unwind_ops);
 223
 224         return start;
 225 }
 226
 227 /*========================= End of Function ========================*/
 228
 229 /*------------------------------------------------------------------*/
 230 /*                                                                  */
 231 /* Name         - throw_exception.                                  */
 232 /*                                                                  */
 233 /* Function     - Raise an exception based on the parameters passed.*/
 234 /*                                                                  */
 235 /*------------------------------------------------------------------*/
 236
 237 static void
 238 throw_exception (MonoObject *exc, unsigned long ip, unsigned long sp,
 239                  gulong *int_regs, gdouble *fp_regs, gint32 *acc_regs,
 240                  guint fpc, gboolean rethrow)
 241 {
 242         MonoContext ctx;
 243         int iReg;
 244
 245         memset(&ctx, 0, sizeof(ctx));
 246
 247         setup_context(&ctx);
 248
 249         /* adjust eip so that it point into the call instruction */
 250         ip -= 2;
 251
 252         for (iReg = 0; iReg < 16; iReg++) {
 253                 ctx.uc_mcontext.gregs[iReg]         = int_regs[iReg];
 254                 ctx.uc_mcontext.fpregs.fprs[iReg].d = fp_regs[iReg];
 255                 ctx.uc_mcontext.aregs[iReg]         = acc_regs[iReg];
 256         }
 257
 258         ctx.uc_mcontext.fpregs.fpc = fpc;
 259
 260         MONO_CONTEXT_SET_BP (&ctx, sp);
 261         MONO_CONTEXT_SET_IP (&ctx, ip);
 262
 263         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 264                 MonoException *mono_ex = (MonoException*)exc;
 265                 if (!rethrow) {
 266                         mono_ex->stack_trace = NULL;
 267                         mono_ex->trace_ips = NULL;
 268                 }
 269         }
 270 //      mono_arch_handle_exception (&ctx, exc, FALSE);
 271         mono_handle_exception (&ctx, exc);
 272         mono_restore_context(&ctx);
 273
 274         g_assert_not_reached ();
 275 }
 276
 277 /*========================= End of Function ========================*/
 278
 279 /*------------------------------------------------------------------*/
 280 /*                                                                  */
 281 /* Name         - get_throw_exception_generic                       */
 282 /*                                                                  */
 283 /* Function     - Return a function pointer which can be used to    */
 284 /*                raise exceptions. The returned function has the   */
 285 /*                following signature:                              */
 286 /*                void (*func) (MonoException *exc); or,            */
 287 /*                void (*func) (char *exc_name);                    */
 288 /*                                                                  */
 289 /*------------------------------------------------------------------*/
 290
 291 static gpointer
 292 mono_arch_get_throw_exception_generic (int size, MonoTrampInfo **info,
 293                                 int corlib, gboolean rethrow, gboolean aot)
 294 {
 295         guint8 *code, *start;
 296         int alloc_size, pos, i;
 297         MonoJumpInfo *ji = NULL;
 298         GSList *unwind_ops = NULL;
 299
 300         code = start = mono_global_codeman_reserve(size);
 301
 302         s390_stmg (code, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
 303         alloc_size = S390_ALIGN(S390_THROWSTACK_SIZE, S390_STACK_ALIGNMENT);
 304         s390_lgr  (code, s390_r14, STK_BASE);
 305         s390_aghi (code, STK_BASE, -alloc_size);
 306         s390_stg  (code, s390_r14, 0, STK_BASE, 0);
 307         s390_lgr  (code, s390_r3, s390_r2);
 308         if (corlib) {
 309                 s390_basr (code, s390_r13, 0);
 310                 s390_j    (code, 10);
 311                 s390_llong(code, mono_defaults.exception_class->image);
 312                 s390_llong(code, mono_exception_from_token);
 313                 s390_lg   (code, s390_r2, 0, s390_r13, 4);
 314                 s390_lg   (code, s390_r1, 0, s390_r13, 12);
 315                 s390_basr (code, s390_r14, s390_r1);
 316         }
 317
 318         /*------------------------------------------------------*/
 319         /* save the general registers on the stack              */
 320         /*------------------------------------------------------*/
 321         s390_stmg (code, s390_r0, s390_r13, STK_BASE, S390_THROWSTACK_INTREGS);
 322
 323         s390_lgr  (code, s390_r1, STK_BASE);
 324         s390_aghi (code, s390_r1, alloc_size);
 325         /*------------------------------------------------------*/
 326         /* save the return address in the parameter register    */
 327         /*------------------------------------------------------*/
 328         s390_lg   (code, s390_r3, 0, s390_r1, S390_RET_ADDR_OFFSET);
 329
 330         /*------------------------------------------------------*/
 331         /* save the floating point registers                    */
 332         /*------------------------------------------------------*/
 333         pos = S390_THROWSTACK_FLTREGS;
 334         for (i = 0; i < 16; ++i) {
 335                 s390_std (code, i, 0, STK_BASE, pos);
 336                 pos += sizeof (gdouble);
 337         }
 338         /*------------------------------------------------------*/
 339         /* save the access registers                            */
 340         /*------------------------------------------------------*/
 341         s390_stam (code, s390_r0, s390_r15, STK_BASE, S390_THROWSTACK_ACCREGS);
 342
 343         /*------------------------------------------------------*/
 344         /* call throw_exception (tkn, ip, sp, gr, fr, ar, re)   */
 345         /* - r2 already contains *exc                           */
 346         /*------------------------------------------------------*/
 347         s390_lgr  (code, s390_r4, s390_r1);        /* caller sp */
 348
 349         /*------------------------------------------------------*/
 350         /* pointer to the saved int regs                        */
 351         /*------------------------------------------------------*/
 352         s390_la   (code, s390_r5, 0, STK_BASE, S390_THROWSTACK_INTREGS);
 353         s390_la   (code, s390_r6, 0, STK_BASE, S390_THROWSTACK_FLTREGS);
 354         s390_la   (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_ACCREGS);
 355         s390_stg  (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_ACCPRM);
 356         s390_stfpc(code, STK_BASE, S390_THROWSTACK_FPCPRM+4);
 357         s390_lghi (code, s390_r7, rethrow);
 358         s390_stg  (code, s390_r7, 0, STK_BASE, S390_THROWSTACK_RETHROW);
 359         s390_basr (code, s390_r13, 0);
 360         s390_j    (code, 6);
 361         s390_llong(code, throw_exception);
 362         s390_lg   (code, s390_r1, 0, s390_r13, 4);
 363         s390_basr (code, s390_r14, s390_r1);
 364         /* we should never reach this breakpoint */
 365         s390_break (code);
 366         g_assert ((code - start) < size);
 367
 368         mono_arch_flush_icache (start, code - start);
 369         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
 370
 371         if (info)
 372                 *info = mono_tramp_info_create (corlib ? "throw_corlib_exception"
 373                                                       : (rethrow ? "rethrow_exception"
 374                                                       : "throw_exception"),
 375                                                 start, code - start, ji, unwind_ops);
 376
 377         return start;
 378 }
 379
 380 /*========================= End of Function ========================*/
 381
 382 /*------------------------------------------------------------------*/
 383 /*                                                                  */
 384 /* Name         - arch_get_throw_exception                          */
 385 /*                                                                  */
 386 /* Function     - Return a function pointer which can be used to    */
 387 /*                raise exceptions. The returned function has the   */
 388 /*                following signature:                              */
 389 /*                void (*func) (MonoException *exc);                */
 390 /*                                                                  */
 391 /*------------------------------------------------------------------*/
 392
 393 gpointer
 394 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
 395 {
 396
 397         g_assert (!aot);
 398         if (info)
 399                 *info = NULL;
 400
 401         return (mono_arch_get_throw_exception_generic (SZ_THROW, info, FALSE, FALSE, aot));
 402 }
 403
 404 /*========================= End of Function ========================*/
 405
 406 /*------------------------------------------------------------------*/
 407 /*                                                                  */
 408 /* Name         - arch_get_rethrow_exception                        */
 409 /*                                                                  */
 410 /* Function     - Return a function pointer which can be used to    */
 411 /*                raise exceptions. The returned function has the   */
 412 /*                following signature:                              */
 413 /*                void (*func) (MonoException *exc);                */
 414 /*                                                                  */
 415 /*------------------------------------------------------------------*/
 416
 417 gpointer
 418 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
 419 {
 420         g_assert (!aot);
 421         if (info)
 422                 *info = NULL;
 423
 424         return (mono_arch_get_throw_exception_generic (SZ_THROW, info, FALSE, TRUE, aot));
 425 }
 426
 427 /*========================= End of Function ========================*/
 428
 429 /*------------------------------------------------------------------*/
 430 /*                                                                  */
 431 /* Name         - arch_get_corlib_exception                         */
 432 /*                                                                  */
 433 /* Function     - Return a function pointer which can be used to    */
 434 /*                raise corlib exceptions. The return function has  */
 435 /*                the following signature:                          */
 436 /*                void (*func) (guint32 token, guint32 offset)      */
 437 /*                                                                  */
 438 /*------------------------------------------------------------------*/
 439
 440 gpointer
 441 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
 442 {
 443         g_assert (!aot);
 444         if (info)
 445                 *info = NULL;
 446
 447         return (mono_arch_get_throw_exception_generic (SZ_THROW, info, TRUE, FALSE, aot));
 448 }
 449
 450 /*========================= End of Function ========================*/
 451
 452 /*------------------------------------------------------------------*/
 453 /*                                                                  */
 454 /* Name         - mono_arch_find_jit_info                           */
 455 /*                                                                  */
 456 /* Function     - See exceptions-amd64.c for docs.                  */
 457 /*                                                                  */
 458 /*------------------------------------------------------------------*/
 459
 460 gboolean
 461 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
 462                          MonoJitInfo *ji, MonoContext *ctx,
 463                          MonoContext *new_ctx, MonoLMF **lmf,
 464                          mgreg_t **save_locations,
 465                          StackFrameInfo *frame)
 466 {
 467         gpointer ip = (gpointer) MONO_CONTEXT_GET_IP (ctx);
 468
 469         memset (frame, 0, sizeof (StackFrameInfo));
 470         frame->ji = ji;
 471
 472         *new_ctx = *ctx;
 473
 474         if (ji != NULL) {
 475                 gint64 address;
 476                 guint8 *cfa;
 477                 guint32 unwind_info_len;
 478                 guint8 *unwind_info;
 479                 mgreg_t regs[16];
 480
 481                 frame->type = FRAME_TYPE_MANAGED;
 482
 483                 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
 484
 485                 address = (char *)ip - (char *)ji->code_start;
 486
 487                 memcpy(&regs, &ctx->uc_mcontext.gregs, sizeof(regs));
 488                 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
 489                                                    (guint8 *) ji->code_start + ji->code_size,
 490                                                    ip, NULL, regs, 16, save_locations,
 491                                                    MONO_MAX_IREGS, &cfa);
 492                 memcpy (&new_ctx->uc_mcontext.gregs, &regs, sizeof(regs));
 493                 MONO_CONTEXT_SET_IP(new_ctx, regs[14] - 2);
 494                 MONO_CONTEXT_SET_BP(new_ctx, cfa);
 495
 496                 return TRUE;
 497         } else if (*lmf) {
 498
 499                 ji = mini_jit_info_table_find (domain, (gpointer)(*lmf)->eip, NULL);
 500                 if (!ji) {
 501                         if (!(*lmf)->method)
 502                                 return FALSE;
 503
 504                         frame->method = (*lmf)->method;
 505                 }
 506
 507                 frame->ji = ji;
 508                 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
 509
 510                 memcpy(new_ctx->uc_mcontext.gregs, (*lmf)->gregs, sizeof((*lmf)->gregs));
 511                 memcpy(new_ctx->uc_mcontext.fpregs.fprs, (*lmf)->fregs, sizeof((*lmf)->fregs));
 512                 MONO_CONTEXT_SET_BP (new_ctx, (*lmf)->ebp);
 513                 MONO_CONTEXT_SET_IP (new_ctx, (*lmf)->eip - 2);
 514                 *lmf = (*lmf)->previous_lmf;
 515
 516                 return TRUE;
 517         }
 518
 519         return FALSE;
 520 }
 521
 522 /*========================= End of Function ========================*/
 523
 524 /*------------------------------------------------------------------*/
 525 /*                                                                  */
 526 /* Name         - handle_signal_exception                           */
 527 /*                                                                  */
 528 /* Function     - Handle an exception raised by the JIT code.       */
 529 /*                                                                  */
 530 /* Parameters   - obj       - The exception object                  */
 531 /*                                                                  */
 532 /*------------------------------------------------------------------*/
 533
 534 static void
 535 handle_signal_exception (gpointer obj)
 536 {
 537         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 538         MonoContext ctx;
 539
 540         memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
 541         mono_handle_exception (&ctx, obj);
 542         mono_restore_context (&ctx);
 543 }
 544
 545 /*========================= End of Function ========================*/
 546
 547 /*------------------------------------------------------------------*/
 548 /*                                                                  */
 549 /* Name         - mono_arch_handle_exception                        */
 550 /*                                                                  */
 551 /* Function     - Handle an exception raised by the JIT code.       */
 552 /*                                                                  */
 553 /* Parameters   - ctx       - Saved processor state                 */
 554 /*                obj       - The exception object                  */
 555 /*                                                                  */
 556 /*------------------------------------------------------------------*/
 557
 558 gboolean
 559 mono_arch_handle_exception (void *sigctx, gpointer obj)
 560 {
 561         MonoContext mctx;
 562
 563         /*
 564          * Handling the exception in the signal handler is problematic, since the original
 565          * signal is disabled, and we could run arbitrary code though the debugger. So
 566          * resume into the normal stack and do most work there if possible.
 567          */
 568         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 569
 570         /* Pass the ctx parameter in TLS */
 571         mono_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
 572
 573         mctx = jit_tls->ex_ctx;
 574         mono_arch_setup_async_callback (&mctx, handle_signal_exception, obj);
 575         mono_monoctx_to_sigctx (&mctx, sigctx);
 576
 577         return TRUE;
 578 }
 579
 580 /*========================= End of Function ========================*/
 581
 582 /*------------------------------------------------------------------*/
 583 /*                                                                  */
 584 /* Name         - mono_arch_setup_async_callback                    */
 585 /*                                                                  */
 586 /* Function     - Establish the async callback.                     */
 587 /*                                                                  */
 588 /* Parameters   - ctx       - Context                               */
 589 /*                async_cb  - Callback routine address              */
 590 /*                user_data - Data to be passed to callback         */
 591 /*                                                                  */
 592 /*------------------------------------------------------------------*/
 593
 594 void
 595 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
 596 {
 597         uintptr_t sp = (uintptr_t) MONO_CONTEXT_GET_SP(ctx);
 598
 599         ctx->uc_mcontext.gregs[2] = (unsigned long) user_data;
 600
 601         sp -= S390_MINIMAL_STACK_SIZE;
 602         *(unsigned long *)sp = MONO_CONTEXT_GET_SP(ctx);
 603         MONO_CONTEXT_SET_BP(ctx, sp);
 604         MONO_CONTEXT_SET_IP(ctx, (unsigned long) async_cb);
 605 }
 606
 607 /*========================= End of Function ========================*/
 608
 609 /*------------------------------------------------------------------*/
 610 /*                                                                  */
 611 /* Name         - mono_arch_ip_from_context                         */
 612 /*                                                                  */
 613 /* Function     - Return the instruction pointer from the context.  */
 614 /*                                                                  */
 615 /* Parameters   - sigctx    - Saved processor state                 */
 616 /*                                                                  */
 617 /*------------------------------------------------------------------*/
 618
 619 gpointer
 620 mono_arch_ip_from_context (void *sigctx)
 621 {
 622         return ((gpointer) MONO_CONTEXT_GET_IP(((MonoContext *) sigctx)));
 623 }
 624
 625
 626 /*========================= End of Function ========================*/
 627
 628 /*------------------------------------------------------------------*/
 629 /*                                                                  */
 630 /* Name         - mono_arch_get_restore_context                    */
 631 /*                                                                  */
 632 /* Function     - Return the address of the routine that will rest- */
 633 /*                ore the context.                                  */
 634 /*                                                                  */
 635 /*------------------------------------------------------------------*/
 636
 637 gpointer
 638 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
 639 {
 640         g_assert (!aot);
 641         if (info)
 642                 *info = NULL;
 643
 644         return setcontext;
 645 }
 646
 647 /*========================= End of Function ========================*/
 648
 649 /*------------------------------------------------------------------*/
 650 /*                                                                  */
 651 /* Name         - mono_arch_is_int_overflow                         */
 652 /*                                                                  */
 653 /* Function     - Inspect the code that raised the SIGFPE signal    */
 654 /*                to see if the DivideByZero or Arithmetic exception*/
 655 /*                should be raised.                                 */
 656 /*                                                                  */
 657 /*------------------------------------------------------------------*/
 658
 659 gboolean
 660 mono_arch_is_int_overflow (void *uc, void *info)
 661 {
 662         MonoContext *ctx;
 663         guint8      *code;
 664         guint64     *operand;
 665         gboolean    arithExc = TRUE;
 666         gint        regNo,
 667                     idxNo,
 668                     offset;
 669
 670         ctx  = (MonoContext *) uc;
 671         code =  (guint8 *) ((siginfo_t *)info)->si_addr;
 672         /*----------------------------------------------------------*/
 673         /* Divide operations are the only ones that will give the   */
 674         /* divide by zero exception so just check for these ops.    */
 675         /*----------------------------------------------------------*/
 676         switch (code[0]) {
 677                 case 0x1d :             /* Divide Register          */
 678                         regNo = code[1] & 0x0f;
 679                         if (ctx->uc_mcontext.gregs[regNo] == 0)
 680                                 arithExc = FALSE;
 681                 break;
 682                 case 0x5d :             /* Divide                   */
 683                         regNo   = (code[2] & 0xf0 >> 8);
 684                         idxNo   = (code[1] & 0x0f);
 685                         offset  = *((guint16 *) code+2) & 0x0fff;
 686                         operand = (guint64*)(ctx->uc_mcontext.gregs[regNo] + offset);
 687                         if (idxNo != 0)
 688                                 operand += ctx->uc_mcontext.gregs[idxNo];
 689                         if (*operand == 0)
 690                                 arithExc = FALSE;
 691                 break;
 692                 case 0xb9 :             /* DL[GR] or DS[GR]         */
 693                         if ((code[1] == 0x97) || (code[1] == 0x87) ||
 694                             (code[1] == 0x0d) || (code[1] == 0x1d)) {
 695                                 regNo = (code[3] & 0x0f);
 696                                 if (ctx->uc_mcontext.gregs[regNo] == 0)
 697                                         arithExc = FALSE;
 698                         }
 699                 break;
 700                 case 0xe3 :             /* DL[G] | DS[G]            */
 701                         if ((code[5] == 0x97) || (code[5] == 0x87) ||
 702                             (code[5] == 0x0d) || (code[5] == 0x1d)) {
 703                                 regNo   = (code[2] & 0xf0 >> 8);
 704                                 idxNo   = (code[1] & 0x0f);
 705                                 offset  = (code[2] & 0x0f << 8) +
 706                                           code[3] + (code[4] << 12);
 707                                 operand = (guint64*)(ctx->uc_mcontext.gregs[regNo] + offset);
 708                                 if (idxNo != 0)
 709                                         operand += ctx->uc_mcontext.gregs[idxNo];
 710                                 if (*operand == 0)
 711                                         arithExc = FALSE;
 712                         }
 713                 break;
 714                 default:
 715                         arithExc = TRUE;
 716         }
 717         ctx->uc_mcontext.psw.addr = (guint64)code;
 718         return (arithExc);
 719 }
 720
 721 /*========================= End of Function ========================*/