mono/mini/exceptions-amd64.c

   1 /*
   2  * exceptions-amd64.c: exception support for AMD64
   3  *
   4  * Authors:
   5  *   Dietmar Maurer (dietmar@ximian.com)
   6  *
   7  * (C) 2001 Ximian, Inc.
   8  * Copyright 2011 Xamarin, Inc (http://www.xamarin.com)
   9  */
  10
  11 #include <config.h>
  12
  13 #include <glib.h>
  14 #include <string.h>
  15
  16 #ifdef HAVE_SIGNAL_H
  17 #include <signal.h>
  18 #endif
  19 #ifdef HAVE_UCONTEXT_H
  20 #include <ucontext.h>
  21 #endif
  22
  23 #include <mono/arch/amd64/amd64-codegen.h>
  24 #include <mono/metadata/abi-details.h>
  25 #include <mono/metadata/appdomain.h>
  26 #include <mono/metadata/tabledefs.h>
  27 #include <mono/metadata/threads.h>
  28 #include <mono/metadata/threads-types.h>
  29 #include <mono/metadata/debug-helpers.h>
  30 #include <mono/metadata/exception.h>
  31 #include <mono/metadata/gc-internal.h>
  32 #include <mono/metadata/mono-debug.h>
  33 #include <mono/utils/mono-mmap.h>
  34
  35 #include "mini.h"
  36 #include "mini-amd64.h"
  37 #include "tasklets.h"
  38
  39 #define ALIGN_TO(val,align) (((val) + ((align) - 1)) & ~((align) - 1))
  40
  41 #ifdef TARGET_WIN32
  42 static MonoW32ExceptionHandler fpe_handler;
  43 static MonoW32ExceptionHandler ill_handler;
  44 static MonoW32ExceptionHandler segv_handler;
  45
  46 LPTOP_LEVEL_EXCEPTION_FILTER mono_old_win_toplevel_exception_filter;
  47 void *mono_win_vectored_exception_handle;
  48
  49 #define W32_SEH_HANDLE_EX(_ex) \
  50         if (_ex##_handler) _ex##_handler(0, ep, ctx)
  51
  52 static LONG CALLBACK seh_unhandled_exception_filter(EXCEPTION_POINTERS* ep)
  53 {
  54 #ifndef MONO_CROSS_COMPILE
  55         if (mono_old_win_toplevel_exception_filter) {
  56                 return (*mono_old_win_toplevel_exception_filter)(ep);
  57         }
  58 #endif
  59
  60         mono_handle_native_sigsegv (SIGSEGV, NULL, NULL);
  61
  62         return EXCEPTION_CONTINUE_SEARCH;
  63 }
  64
  65 /*
  66  * Unhandled Exception Filter
  67  * Top-level per-process exception handler.
  68  */
  69 static LONG CALLBACK seh_vectored_exception_handler(EXCEPTION_POINTERS* ep)
  70 {
  71         EXCEPTION_RECORD* er;
  72         CONTEXT* ctx;
  73         LONG res;
  74         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
  75
  76         /* If the thread is not managed by the runtime return early */
  77         if (!jit_tls)
  78                 return EXCEPTION_CONTINUE_SEARCH;
  79
  80         jit_tls->mono_win_chained_exception_needs_run = FALSE;
  81         res = EXCEPTION_CONTINUE_EXECUTION;
  82
  83         er = ep->ExceptionRecord;
  84         ctx = ep->ContextRecord;
  85
  86         switch (er->ExceptionCode) {
  87         case EXCEPTION_ACCESS_VIOLATION:
  88                 W32_SEH_HANDLE_EX(segv);
  89                 break;
  90         case EXCEPTION_ILLEGAL_INSTRUCTION:
  91                 W32_SEH_HANDLE_EX(ill);
  92                 break;
  93         case EXCEPTION_INT_DIVIDE_BY_ZERO:
  94         case EXCEPTION_INT_OVERFLOW:
  95         case EXCEPTION_FLT_DIVIDE_BY_ZERO:
  96         case EXCEPTION_FLT_OVERFLOW:
  97         case EXCEPTION_FLT_UNDERFLOW:
  98         case EXCEPTION_FLT_INEXACT_RESULT:
  99                 W32_SEH_HANDLE_EX(fpe);
 100                 break;
 101         default:
 102                 jit_tls->mono_win_chained_exception_needs_run = TRUE;
 103                 break;
 104         }
 105
 106         if (jit_tls->mono_win_chained_exception_needs_run) {
 107                 /* Don't copy context back if we chained exception
 108                 * as the handler may have modfied the EXCEPTION_POINTERS
 109                 * directly. We don't pass sigcontext to chained handlers.
 110                 * Return continue search so the UnhandledExceptionFilter
 111                 * can correctly chain the exception.
 112                 */
 113                 res = EXCEPTION_CONTINUE_SEARCH;
 114         }
 115
 116         return res;
 117 }
 118
 119 void win32_seh_init()
 120 {
 121         mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
 122         mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
 123 }
 124
 125 void win32_seh_cleanup()
 126 {
 127         guint32 ret = 0;
 128
 129         if (mono_old_win_toplevel_exception_filter) SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
 130
 131         ret = RemoveVectoredExceptionHandler (mono_win_vectored_exception_handle);
 132         g_assert (ret);
 133 }
 134
 135 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
 136 {
 137         switch (type) {
 138         case SIGFPE:
 139                 fpe_handler = handler;
 140                 break;
 141         case SIGILL:
 142                 ill_handler = handler;
 143                 break;
 144         case SIGSEGV:
 145                 segv_handler = handler;
 146                 break;
 147         default:
 148                 break;
 149         }
 150 }
 151
 152 #endif /* TARGET_WIN32 */
 153
 154 /*
 155  * mono_arch_get_restore_context:
 156  *
 157  * Returns a pointer to a method which restores a previously saved sigcontext.
 158  */
 159 gpointer
 160 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
 161 {
 162         guint8 *start = NULL;
 163         guint8 *code;
 164         MonoJumpInfo *ji = NULL;
 165         GSList *unwind_ops = NULL;
 166         int i, gregs_offset;
 167
 168         /* restore_contect (MonoContext *ctx) */
 169
 170         start = code = mono_global_codeman_reserve (256);
 171
 172         amd64_mov_reg_reg (code, AMD64_R11, AMD64_ARG_REG1, 8);
 173
 174         /* Restore all registers except %rip and %r11 */
 175         gregs_offset = MONO_STRUCT_OFFSET (MonoContext, gregs);
 176         for (i = 0; i < AMD64_NREG; ++i) {
 177 #if defined(__native_client_codegen__)
 178                 if (i == AMD64_R15)
 179                         continue;
 180 #endif
 181                 if (i != AMD64_RIP && i != AMD64_RSP && i != AMD64_R8 && i != AMD64_R9 && i != AMD64_R10 && i != AMD64_R11)
 182                         amd64_mov_reg_membase (code, i, AMD64_R11, gregs_offset + (i * 8), 8);
 183         }
 184
 185         /*
 186          * The context resides on the stack, in the stack frame of the
 187          * caller of this function.  The stack pointer that we need to
 188          * restore is potentially many stack frames higher up, so the
 189          * distance between them can easily be more than the red zone
 190          * size.  Hence the stack pointer can be restored only after
 191          * we have finished loading everything from the context.
 192          */
 193         amd64_mov_reg_membase (code, AMD64_R8, AMD64_R11,  gregs_offset + (AMD64_RSP * 8), 8);
 194         amd64_mov_reg_membase (code, AMD64_R11, AMD64_R11,  gregs_offset + (AMD64_RIP * 8), 8);
 195         amd64_mov_reg_reg (code, AMD64_RSP, AMD64_R8, 8);
 196
 197         /* jump to the saved IP */
 198         amd64_jump_reg (code, AMD64_R11);
 199
 200         nacl_global_codeman_validate (&start, 256, &code);
 201
 202         mono_arch_flush_icache (start, code - start);
 203         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
 204
 205         if (info)
 206                 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
 207
 208         return start;
 209 }
 210
 211 /*
 212  * mono_arch_get_call_filter:
 213  *
 214  * Returns a pointer to a method which calls an exception filter. We
 215  * also use this function to call finally handlers (we pass NULL as
 216  * @exc object in this case).
 217  */
 218 gpointer
 219 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
 220 {
 221         guint8 *start;
 222         int i, gregs_offset;
 223         guint8 *code;
 224         guint32 pos;
 225         MonoJumpInfo *ji = NULL;
 226         GSList *unwind_ops = NULL;
 227         const guint kMaxCodeSize = NACL_SIZE (128, 256);
 228
 229         start = code = mono_global_codeman_reserve (kMaxCodeSize);
 230
 231         /* call_filter (MonoContext *ctx, unsigned long eip) */
 232         code = start;
 233
 234         /* Alloc new frame */
 235         amd64_push_reg (code, AMD64_RBP);
 236         amd64_mov_reg_reg (code, AMD64_RBP, AMD64_RSP, 8);
 237
 238         /* Save callee saved regs */
 239         pos = 0;
 240         for (i = 0; i < AMD64_NREG; ++i)
 241                 if (AMD64_IS_CALLEE_SAVED_REG (i)) {
 242                         amd64_push_reg (code, i);
 243                         pos += 8;
 244                 }
 245
 246         /* Save EBP */
 247         pos += 8;
 248         amd64_push_reg (code, AMD64_RBP);
 249
 250         /* Make stack misaligned, the call will make it aligned again */
 251         if (! (pos & 8))
 252                 amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 253
 254         gregs_offset = MONO_STRUCT_OFFSET (MonoContext, gregs);
 255
 256         /* set new EBP */
 257         amd64_mov_reg_membase (code, AMD64_RBP, AMD64_ARG_REG1, gregs_offset + (AMD64_RBP * 8), 8);
 258         /* load callee saved regs */
 259         for (i = 0; i < AMD64_NREG; ++i) {
 260 #if defined(__native_client_codegen__)
 261                 if (i == AMD64_R15)
 262                         continue;
 263 #endif
 264                 if (AMD64_IS_CALLEE_SAVED_REG (i) && i != AMD64_RBP)
 265                         amd64_mov_reg_membase (code, AMD64_RBX, AMD64_ARG_REG1, gregs_offset + (i * 8), 8);
 266         }
 267         /* load exc register */
 268         amd64_mov_reg_membase (code, AMD64_RAX, AMD64_ARG_REG1,  gregs_offset + (AMD64_RAX * 8), 8);
 269
 270         /* call the handler */
 271         amd64_call_reg (code, AMD64_ARG_REG2);
 272
 273         if (! (pos & 8))
 274                 amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 8);
 275
 276         /* restore RBP */
 277         amd64_pop_reg (code, AMD64_RBP);
 278
 279         /* Restore callee saved regs */
 280         for (i = AMD64_NREG; i >= 0; --i)
 281                 if (AMD64_IS_CALLEE_SAVED_REG (i))
 282                         amd64_pop_reg (code, i);
 283
 284         amd64_leave (code);
 285         amd64_ret (code);
 286
 287         g_assert ((code - start) < kMaxCodeSize);
 288
 289         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
 290
 291         mono_arch_flush_icache (start, code - start);
 292         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
 293
 294         if (info)
 295                 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
 296
 297         return start;
 298 }
 299
 300 /*
 301  * The first few arguments are dummy, to force the other arguments to be passed on
 302  * the stack, this avoids overwriting the argument registers in the throw trampoline.
 303  */
 304 void
 305 mono_amd64_throw_exception (guint64 dummy1, guint64 dummy2, guint64 dummy3, guint64 dummy4,
 306                                                         guint64 dummy5, guint64 dummy6,
 307                                                         MonoContext *mctx, MonoObject *exc, gboolean rethrow)
 308 {
 309         MonoContext ctx;
 310
 311         /* mctx is on the caller's stack */
 312         memcpy (&ctx, mctx, sizeof (MonoContext));
 313
 314         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 315                 MonoException *mono_ex = (MonoException*)exc;
 316                 if (!rethrow) {
 317                         mono_ex->stack_trace = NULL;
 318                         mono_ex->trace_ips = NULL;
 319                 }
 320         }
 321
 322         /* adjust eip so that it point into the call instruction */
 323         ctx.gregs [AMD64_RIP] --;
 324
 325         mono_handle_exception (&ctx, exc);
 326         mono_restore_context (&ctx);
 327         g_assert_not_reached ();
 328 }
 329
 330 void
 331 mono_amd64_throw_corlib_exception (guint64 dummy1, guint64 dummy2, guint64 dummy3, guint64 dummy4,
 332                                                                    guint64 dummy5, guint64 dummy6,
 333                                                                    MonoContext *mctx, guint32 ex_token_index, gint64 pc_offset)
 334 {
 335         guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
 336         MonoException *ex;
 337
 338         ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
 339
 340         mctx->gregs [AMD64_RIP] -= pc_offset;
 341
 342         /* Negate the ip adjustment done in mono_amd64_throw_exception () */
 343         mctx->gregs [AMD64_RIP] += 1;
 344
 345         mono_amd64_throw_exception (dummy1, dummy2, dummy3, dummy4, dummy5, dummy6, mctx, (MonoObject*)ex, FALSE);
 346 }
 347
 348 static void
 349 mono_amd64_resume_unwind (guint64 dummy1, guint64 dummy2, guint64 dummy3, guint64 dummy4,
 350                                                   guint64 dummy5, guint64 dummy6,
 351                                                   MonoContext *mctx, guint32 dummy7, gint64 dummy8)
 352 {
 353         /* Only the register parameters are valid */
 354         MonoContext ctx;
 355
 356         /* mctx is on the caller's stack */
 357         memcpy (&ctx, mctx, sizeof (MonoContext));
 358
 359         mono_resume_unwind (&ctx);
 360 }
 361
 362 /*
 363  * get_throw_trampoline:
 364  *
 365  *  Generate a call to mono_amd64_throw_exception/
 366  * mono_amd64_throw_corlib_exception.
 367  */
 368 static gpointer
 369 get_throw_trampoline (MonoTrampInfo **info, gboolean rethrow, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, const char *tramp_name, gboolean aot)
 370 {
 371         guint8* start;
 372         guint8 *code;
 373         MonoJumpInfo *ji = NULL;
 374         GSList *unwind_ops = NULL;
 375         int i, stack_size, arg_offsets [16], ctx_offset, regs_offset, dummy_stack_space;
 376         const guint kMaxCodeSize = NACL_SIZE (256, 512);
 377
 378 #ifdef TARGET_WIN32
 379         dummy_stack_space = 6 * sizeof(mgreg_t);        /* Windows expects stack space allocated for all 6 dummy args. */
 380 #else
 381         dummy_stack_space = 0;
 382 #endif
 383
 384         start = code = mono_global_codeman_reserve (kMaxCodeSize);
 385
 386         /* The stack is unaligned on entry */
 387         stack_size = ALIGN_TO (sizeof (MonoContext) + 64 + dummy_stack_space, MONO_ARCH_FRAME_ALIGNMENT) + 8;
 388
 389         code = start;
 390
 391         if (info)
 392                 unwind_ops = mono_arch_get_cie_program ();
 393
 394         /* Alloc frame */
 395         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, stack_size);
 396         if (info)
 397                 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 8);
 398
 399         /*
 400          * To hide linux/windows calling convention differences, we pass all arguments on
 401          * the stack by passing 6 dummy values in registers.
 402          */
 403
 404         arg_offsets [0] = dummy_stack_space + 0;
 405         arg_offsets [1] = dummy_stack_space + sizeof(mgreg_t);
 406         arg_offsets [2] = dummy_stack_space + sizeof(mgreg_t) * 2;
 407         ctx_offset = dummy_stack_space + sizeof(mgreg_t) * 4;
 408         regs_offset = ctx_offset + MONO_STRUCT_OFFSET (MonoContext, gregs);
 409
 410         /* Save registers */
 411         for (i = 0; i < AMD64_NREG; ++i)
 412                 if (i != AMD64_RSP)
 413                         amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (i * sizeof(mgreg_t)), i, sizeof(mgreg_t));
 414         /* Save RSP */
 415         amd64_lea_membase (code, AMD64_RAX, AMD64_RSP, stack_size + sizeof(mgreg_t));
 416         amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (AMD64_RSP * sizeof(mgreg_t)), X86_EAX, sizeof(mgreg_t));
 417         /* Save IP */
 418         if (llvm_abs)
 419                 amd64_alu_reg_reg (code, X86_XOR, AMD64_RAX, AMD64_RAX);
 420         else
 421                 amd64_mov_reg_membase (code, AMD64_RAX, AMD64_RSP, stack_size, sizeof(mgreg_t));
 422         amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (AMD64_RIP * sizeof(mgreg_t)), AMD64_RAX, sizeof(mgreg_t));
 423         /* Set arg1 == ctx */
 424         amd64_lea_membase (code, AMD64_RAX, AMD64_RSP, ctx_offset);
 425         amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [0], AMD64_RAX, sizeof(mgreg_t));
 426         /* Set arg2 == exc/ex_token_index */
 427         if (resume_unwind)
 428                 amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [1], 0, sizeof(mgreg_t));
 429         else
 430                 amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [1], AMD64_ARG_REG1, sizeof(mgreg_t));
 431         /* Set arg3 == rethrow/pc offset */
 432         if (resume_unwind) {
 433                 amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [2], 0, sizeof(mgreg_t));
 434         } else if (corlib) {
 435                 amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [2], AMD64_ARG_REG2, sizeof(mgreg_t));
 436                 if (llvm_abs)
 437                         /*
 438                          * The caller is LLVM code which passes the absolute address not a pc offset,
 439                          * so compensate by passing 0 as 'rip' and passing the negated abs address as
 440                          * the pc offset.
 441                          */
 442                         amd64_neg_membase (code, AMD64_RSP, arg_offsets [2]);
 443         } else {
 444                 amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [2], rethrow, sizeof(mgreg_t));
 445         }
 446
 447         if (aot) {
 448                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, corlib ? "mono_amd64_throw_corlib_exception" : "mono_amd64_throw_exception");
 449                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 450         } else {
 451                 amd64_mov_reg_imm (code, AMD64_R11, resume_unwind ? ((gpointer)mono_amd64_resume_unwind) : (corlib ? (gpointer)mono_amd64_throw_corlib_exception : (gpointer)mono_amd64_throw_exception));
 452         }
 453         amd64_call_reg (code, AMD64_R11);
 454         amd64_breakpoint (code);
 455
 456         mono_arch_flush_icache (start, code - start);
 457
 458         g_assert ((code - start) < kMaxCodeSize);
 459
 460         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
 461         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
 462
 463         if (info)
 464                 *info = mono_tramp_info_create (tramp_name, start, code - start, ji, unwind_ops);
 465
 466         return start;
 467 }
 468
 469 /**
 470  * mono_arch_get_throw_exception:
 471  *
 472  * Returns a function pointer which can be used to raise
 473  * exceptions. The returned function has the following
 474  * signature: void (*func) (MonoException *exc);
 475  *
 476  */
 477 gpointer
 478 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
 479 {
 480         return get_throw_trampoline (info, FALSE, FALSE, FALSE, FALSE, "throw_exception", aot);
 481 }
 482
 483 gpointer
 484 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
 485 {
 486         return get_throw_trampoline (info, TRUE, FALSE, FALSE, FALSE, "rethrow_exception", aot);
 487 }
 488
 489 /**
 490  * mono_arch_get_throw_corlib_exception:
 491  *
 492  * Returns a function pointer which can be used to raise
 493  * corlib exceptions. The returned function has the following
 494  * signature: void (*func) (guint32 ex_token, guint32 offset);
 495  * Here, offset is the offset which needs to be substracted from the caller IP
 496  * to get the IP of the throw. Passing the offset has the advantage that it
 497  * needs no relocations in the caller.
 498  */
 499 gpointer
 500 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
 501 {
 502         return get_throw_trampoline (info, FALSE, TRUE, FALSE, FALSE, "throw_corlib_exception", aot);
 503 }
 504
 505 /*
 506  * mono_arch_find_jit_info:
 507  *
 508  * This function is used to gather information from @ctx, and store it in @frame_info.
 509  * It unwinds one stack frame, and stores the resulting context into @new_ctx. @lmf
 510  * is modified if needed.
 511  * Returns TRUE on success, FALSE otherwise.
 512  */
 513 gboolean
 514 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
 515                                                          MonoJitInfo *ji, MonoContext *ctx,
 516                                                          MonoContext *new_ctx, MonoLMF **lmf,
 517                                                          mgreg_t **save_locations,
 518                                                          StackFrameInfo *frame)
 519 {
 520         gpointer ip = MONO_CONTEXT_GET_IP (ctx);
 521         int i;
 522
 523         memset (frame, 0, sizeof (StackFrameInfo));
 524         frame->ji = ji;
 525
 526         *new_ctx = *ctx;
 527
 528         if (ji != NULL) {
 529                 mgreg_t regs [MONO_MAX_IREGS + 1];
 530                 guint8 *cfa;
 531                 guint32 unwind_info_len;
 532                 guint8 *unwind_info;
 533                 guint8 *epilog = NULL;
 534
 535                 frame->type = FRAME_TYPE_MANAGED;
 536
 537                 unwind_info = mono_jinfo_get_unwind_info (ji, &unwind_info_len);
 538
 539                 frame->unwind_info = unwind_info;
 540                 frame->unwind_info_len = unwind_info_len;
 541
 542                 /*
 543                 printf ("%s %p %p\n", ji->d.method->name, ji->code_start, ip);
 544                 mono_print_unwind_info (unwind_info, unwind_info_len);
 545                 */
 546                 /* LLVM compiled code doesn't have this info */
 547                 if (ji->has_arch_eh_info)
 548                         epilog = (guint8*)ji->code_start + ji->code_size - mono_jinfo_get_epilog_size (ji);
 549
 550                 for (i = 0; i < AMD64_NREG; ++i)
 551                         regs [i] = new_ctx->gregs [i];
 552
 553                 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
 554                                                    (guint8*)ji->code_start + ji->code_size,
 555                                                    ip, epilog ? &epilog : NULL, regs, MONO_MAX_IREGS + 1,
 556                                                    save_locations, MONO_MAX_IREGS, &cfa);
 557
 558                 for (i = 0; i < AMD64_NREG; ++i)
 559                         new_ctx->gregs [i] = regs [i];
 560
 561                 /* The CFA becomes the new SP value */
 562                 new_ctx->gregs [AMD64_RSP] = (mgreg_t)cfa;
 563
 564                 /* Adjust IP */
 565                 new_ctx->gregs [AMD64_RIP] --;
 566
 567                 return TRUE;
 568         } else if (*lmf) {
 569                 guint64 rip;
 570
 571                 if (((guint64)(*lmf)->previous_lmf) & 2) {
 572                         /*
 573                          * This LMF entry is created by the soft debug code to mark transitions to
 574                          * managed code done during invokes.
 575                          */
 576                         MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
 577
 578                         g_assert (ext->debugger_invoke);
 579
 580                         memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
 581
 582                         *lmf = (gpointer)(((guint64)(*lmf)->previous_lmf) & ~7);
 583
 584                         frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
 585
 586                         return TRUE;
 587                 }
 588
 589                 if (((guint64)(*lmf)->previous_lmf) & 4) {
 590                         MonoLMFTramp *ext = (MonoLMFTramp*)(*lmf);
 591
 592                         rip = (guint64)MONO_CONTEXT_GET_IP (ext->ctx);
 593                 } else if (((guint64)(*lmf)->previous_lmf) & 1) {
 594                         /* This LMF has the rip field set */
 595                         rip = (*lmf)->rip;
 596                 } else if ((*lmf)->rsp == 0) {
 597                         /* Top LMF entry */
 598                         return FALSE;
 599                 } else {
 600                         /*
 601                          * The rsp field is set just before the call which transitioned to native
 602                          * code. Obtain the rip from the stack.
 603                          */
 604                         rip = *(guint64*)((*lmf)->rsp - sizeof(mgreg_t));
 605                 }
 606
 607                 ji = mini_jit_info_table_find (domain, (gpointer)rip, NULL);
 608                 /*
 609                  * FIXME: ji == NULL can happen when a managed-to-native wrapper is interrupted
 610                  * in the soft debugger suspend code, since (*lmf)->rsp no longer points to the
 611                  * return address.
 612                  */
 613                 //g_assert (ji);
 614                 if (!ji)
 615                         return FALSE;
 616
 617                 frame->ji = ji;
 618                 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
 619
 620                 if (((guint64)(*lmf)->previous_lmf) & 4) {
 621                         MonoLMFTramp *ext = (MonoLMFTramp*)(*lmf);
 622
 623                         /* Trampoline frame */
 624                         for (i = 0; i < AMD64_NREG; ++i)
 625                                 new_ctx->gregs [i] = ext->ctx->gregs [i];
 626                         /* Adjust IP */
 627                         new_ctx->gregs [AMD64_RIP] --;
 628                 } else {
 629                         /*
 630                          * The registers saved in the LMF will be restored using the normal unwind info,
 631                          * when the wrapper frame is processed.
 632                          */
 633                         /* Adjust IP */
 634                         rip --;
 635                         new_ctx->gregs [AMD64_RIP] = rip;
 636                         new_ctx->gregs [AMD64_RSP] = (*lmf)->rsp;
 637                         new_ctx->gregs [AMD64_RBP] = (*lmf)->rbp;
 638                         for (i = 0; i < AMD64_NREG; ++i) {
 639                                 if (AMD64_IS_CALLEE_SAVED_REG (i) && i != AMD64_RBP)
 640                                         new_ctx->gregs [i] = 0;
 641                         }
 642                 }
 643
 644                 *lmf = (gpointer)(((guint64)(*lmf)->previous_lmf) & ~7);
 645
 646                 return TRUE;
 647         }
 648
 649         return FALSE;
 650 }
 651
 652 /*
 653  * handle_exception:
 654  *
 655  *   Called by resuming from a signal handler.
 656  */
 657 static void
 658 handle_signal_exception (gpointer obj)
 659 {
 660         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 661         MonoContext ctx;
 662
 663         memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
 664
 665         mono_handle_exception (&ctx, obj);
 666
 667         mono_restore_context (&ctx);
 668 }
 669
 670 void
 671 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
 672 {
 673         guint64 sp = ctx->gregs [AMD64_RSP];
 674
 675         ctx->gregs [AMD64_RDI] = (guint64)user_data;
 676
 677         /* Allocate a stack frame below the red zone */
 678         sp -= 128;
 679         /* The stack should be unaligned */
 680         if ((sp % 16) == 0)
 681                 sp -= 8;
 682 #ifdef __linux__
 683         /* Preserve the call chain to prevent crashes in the libgcc unwinder (#15969) */
 684         *(guint64*)sp = ctx->gregs [AMD64_RIP];
 685 #endif
 686         ctx->gregs [AMD64_RSP] = sp;
 687         ctx->gregs [AMD64_RIP] = (guint64)async_cb;
 688 }
 689
 690 /**
 691  * mono_arch_handle_exception:
 692  *
 693  * @ctx: saved processor state
 694  * @obj: the exception object
 695  */
 696 gboolean
 697 mono_arch_handle_exception (void *sigctx, gpointer obj)
 698 {
 699 #if defined(MONO_ARCH_USE_SIGACTION)
 700         MonoContext mctx;
 701
 702         /*
 703          * Handling the exception in the signal handler is problematic, since the original
 704          * signal is disabled, and we could run arbitrary code though the debugger. So
 705          * resume into the normal stack and do most work there if possible.
 706          */
 707         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 708
 709         /* Pass the ctx parameter in TLS */
 710         mono_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
 711
 712         mctx = jit_tls->ex_ctx;
 713         mono_arch_setup_async_callback (&mctx, handle_signal_exception, obj);
 714         mono_monoctx_to_sigctx (&mctx, sigctx);
 715
 716         return TRUE;
 717 #else
 718         MonoContext mctx;
 719
 720         mono_sigctx_to_monoctx (sigctx, &mctx);
 721
 722         mono_handle_exception (&mctx, obj);
 723
 724         mono_monoctx_to_sigctx (&mctx, sigctx);
 725
 726         return TRUE;
 727 #endif
 728 }
 729
 730 gpointer
 731 mono_arch_ip_from_context (void *sigctx)
 732 {
 733 #if defined(MONO_ARCH_USE_SIGACTION)
 734         ucontext_t *ctx = (ucontext_t*)sigctx;
 735
 736         return (gpointer)UCONTEXT_REG_RIP (ctx);
 737 #elif defined(HOST_WIN32)
 738         return ((CONTEXT*)sigctx)->Rip;
 739 #else
 740         MonoContext *ctx = sigctx;
 741         return (gpointer)ctx->gregs [AMD64_RIP];
 742 #endif
 743 }
 744
 745 static void
 746 restore_soft_guard_pages (void)
 747 {
 748         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 749         if (jit_tls->stack_ovf_guard_base)
 750                 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
 751 }
 752
 753 /*
 754  * this function modifies mctx so that when it is restored, it
 755  * won't execcute starting at mctx.eip, but in a function that
 756  * will restore the protection on the soft-guard pages and return back to
 757  * continue at mctx.eip.
 758  */
 759 static void
 760 prepare_for_guard_pages (MonoContext *mctx)
 761 {
 762         gpointer *sp;
 763         sp = (gpointer)(mctx->gregs [AMD64_RSP]);
 764         sp -= 1;
 765         /* the return addr */
 766         sp [0] = (gpointer)(mctx->gregs [AMD64_RIP]);
 767         mctx->gregs [AMD64_RIP] = (guint64)restore_soft_guard_pages;
 768         mctx->gregs [AMD64_RSP] = (guint64)sp;
 769 }
 770
 771 static void
 772 altstack_handle_and_restore (MonoContext *ctx, gpointer obj, gboolean stack_ovf)
 773 {
 774         MonoContext mctx;
 775
 776         mctx = *ctx;
 777
 778         mono_handle_exception (&mctx, obj);
 779         if (stack_ovf)
 780                 prepare_for_guard_pages (&mctx);
 781         mono_restore_context (&mctx);
 782 }
 783
 784 void
 785 mono_arch_handle_altstack_exception (void *sigctx, MONO_SIG_HANDLER_INFO_TYPE *siginfo, gpointer fault_addr, gboolean stack_ovf)
 786 {
 787 #if defined(MONO_ARCH_USE_SIGACTION)
 788         MonoException *exc = NULL;
 789         MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_RIP (sigctx), NULL);
 790         gpointer *sp;
 791         int frame_size;
 792         MonoContext *copied_ctx;
 793
 794         if (stack_ovf)
 795                 exc = mono_domain_get ()->stack_overflow_ex;
 796         if (!ji)
 797                 mono_handle_native_sigsegv (SIGSEGV, sigctx, siginfo);
 798
 799         /* setup a call frame on the real stack so that control is returned there
 800          * and exception handling can continue.
 801          * The frame looks like:
 802          *   ucontext struct
 803          *   ...
 804          *   return ip
 805          * 128 is the size of the red zone
 806          */
 807         frame_size = sizeof (MonoContext) + sizeof (gpointer) * 4 + 128;
 808         frame_size += 15;
 809         frame_size &= ~15;
 810         sp = (gpointer)(UCONTEXT_REG_RSP (sigctx) & ~15);
 811         sp = (gpointer)((char*)sp - frame_size);
 812         copied_ctx = (MonoContext*)(sp + 4);
 813         /* the arguments must be aligned */
 814         sp [-1] = (gpointer)UCONTEXT_REG_RIP (sigctx);
 815         mono_sigctx_to_monoctx (sigctx, copied_ctx);
 816         /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
 817         UCONTEXT_REG_RIP (sigctx) = (unsigned long)altstack_handle_and_restore;
 818         UCONTEXT_REG_RSP (sigctx) = (unsigned long)(sp - 1);
 819         UCONTEXT_REG_RDI (sigctx) = (unsigned long)(copied_ctx);
 820         UCONTEXT_REG_RSI (sigctx) = (guint64)exc;
 821         UCONTEXT_REG_RDX (sigctx) = stack_ovf;
 822 #endif
 823 }
 824
 825 guint64
 826 mono_amd64_get_original_ip (void)
 827 {
 828         MonoLMF *lmf = mono_get_lmf ();
 829
 830         g_assert (lmf);
 831
 832         /* Reset the change to previous_lmf */
 833         lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf & ~1);
 834
 835         return lmf->rip;
 836 }
 837
 838 gpointer
 839 mono_arch_get_throw_pending_exception (MonoTrampInfo **info, gboolean aot)
 840 {
 841         guint8 *code, *start;
 842         guint8 *br[1];
 843         gpointer throw_trampoline;
 844         MonoJumpInfo *ji = NULL;
 845         GSList *unwind_ops = NULL;
 846         const guint kMaxCodeSize = NACL_SIZE (128, 256);
 847
 848         start = code = mono_global_codeman_reserve (kMaxCodeSize);
 849
 850         /* We are in the frame of a managed method after a call */
 851         /*
 852          * We would like to throw the pending exception in such a way that it looks to
 853          * be thrown from the managed method.
 854          */
 855
 856         /* Save registers which might contain the return value of the call */
 857         amd64_push_reg (code, AMD64_RAX);
 858         amd64_push_reg (code, AMD64_RDX);
 859
 860         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 861         amd64_movsd_membase_reg (code, AMD64_RSP, 0, AMD64_XMM0);
 862
 863         /* Align stack */
 864         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 865
 866         /* Obtain the pending exception */
 867         if (aot) {
 868                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_thread_get_and_clear_pending_exception");
 869                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 870         } else {
 871                 amd64_mov_reg_imm (code, AMD64_R11, mono_thread_get_and_clear_pending_exception);
 872         }
 873         amd64_call_reg (code, AMD64_R11);
 874
 875         /* Check if it is NULL, and branch */
 876         amd64_alu_reg_imm (code, X86_CMP, AMD64_RAX, 0);
 877         br[0] = code; x86_branch8 (code, X86_CC_EQ, 0, FALSE);
 878
 879         /* exc != NULL branch */
 880
 881         /* Save the exc on the stack */
 882         amd64_push_reg (code, AMD64_RAX);
 883         /* Align stack */
 884         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 885
 886         /* Obtain the original ip and clear the flag in previous_lmf */
 887         if (aot) {
 888                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_amd64_get_original_ip");
 889                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 890         } else {
 891                 amd64_mov_reg_imm (code, AMD64_R11, mono_amd64_get_original_ip);
 892         }
 893         amd64_call_reg (code, AMD64_R11);
 894
 895         /* Load exc */
 896         amd64_mov_reg_membase (code, AMD64_R11, AMD64_RSP, 8, 8);
 897
 898         /* Pop saved stuff from the stack */
 899         amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 6 * 8);
 900
 901         /* Setup arguments for the throw trampoline */
 902         /* Exception */
 903         amd64_mov_reg_reg (code, AMD64_ARG_REG1, AMD64_R11, 8);
 904         /* The trampoline expects the caller ip to be pushed on the stack */
 905         amd64_push_reg (code, AMD64_RAX);
 906
 907         /* Call the throw trampoline */
 908         if (aot) {
 909                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_throw_exception");
 910                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 911         } else {
 912                 throw_trampoline = mono_get_throw_exception ();
 913                 amd64_mov_reg_imm (code, AMD64_R11, throw_trampoline);
 914         }
 915         /* We use a jump instead of a call so we can push the original ip on the stack */
 916         amd64_jump_reg (code, AMD64_R11);
 917
 918         /* ex == NULL branch */
 919         mono_amd64_patch (br [0], code);
 920
 921         /* Obtain the original ip and clear the flag in previous_lmf */
 922         if (aot) {
 923                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_amd64_get_original_ip");
 924                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 925         } else {
 926                 amd64_mov_reg_imm (code, AMD64_R11, mono_amd64_get_original_ip);
 927         }
 928         amd64_call_reg (code, AMD64_R11);
 929         amd64_mov_reg_reg (code, AMD64_R11, AMD64_RAX, 8);
 930
 931         /* Restore registers */
 932         amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 8);
 933         amd64_movsd_reg_membase (code, AMD64_XMM0, AMD64_RSP, 0);
 934         amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 8);
 935         amd64_pop_reg (code, AMD64_RDX);
 936         amd64_pop_reg (code, AMD64_RAX);
 937
 938         /* Return to original code */
 939         amd64_jump_reg (code, AMD64_R11);
 940
 941         g_assert ((code - start) < kMaxCodeSize);
 942
 943         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
 944         mono_arch_flush_icache (start, code - start);
 945         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
 946
 947         if (info)
 948                 *info = mono_tramp_info_create ("throw_pending_exception", start, code - start, ji, unwind_ops);
 949
 950         return start;
 951 }
 952
 953 static gpointer throw_pending_exception;
 954
 955 /*
 956  * Called when a thread receives an async exception while executing unmanaged code.
 957  * Instead of checking for this exception in the managed-to-native wrapper, we hijack
 958  * the return address on the stack to point to a helper routine which throws the
 959  * exception.
 960  */
 961 void
 962 mono_arch_notify_pending_exc (MonoThreadInfo *info)
 963 {
 964         MonoLMF *lmf = mono_get_lmf ();
 965
 966         if (!info) {
 967                 lmf = mono_get_lmf ();
 968         } else {
 969                 g_assert (mono_thread_info_get_suspend_state (info)->valid);
 970                 lmf = mono_thread_info_get_suspend_state (info)->unwind_data [MONO_UNWIND_DATA_LMF];
 971         }
 972
 973         if (!lmf)
 974                 /* Not yet started */
 975                 return;
 976
 977         if (lmf->rsp == 0)
 978                 /* Initial LMF */
 979                 return;
 980
 981         if ((guint64)lmf->previous_lmf & 5)
 982                 /* Already hijacked or trampoline LMF entry */
 983                 return;
 984
 985         /* lmf->rsp is set just before making the call which transitions to unmanaged code */
 986         lmf->rip = *(guint64*)(lmf->rsp - 8);
 987         /* Signal that lmf->rip is set */
 988         lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf | 1);
 989
 990         *(gpointer*)(lmf->rsp - 8) = throw_pending_exception;
 991 }
 992
 993 GSList*
 994 mono_amd64_get_exception_trampolines (gboolean aot)
 995 {
 996         MonoTrampInfo *info;
 997         GSList *tramps = NULL;
 998
 999         mono_arch_get_throw_pending_exception (&info, aot);
1000         tramps = g_slist_prepend (tramps, info);
1001
1002         /* LLVM needs different throw trampolines */
1003         get_throw_trampoline (&info, FALSE, TRUE, FALSE, FALSE, "llvm_throw_corlib_exception_trampoline", aot);
1004         tramps = g_slist_prepend (tramps, info);
1005
1006         get_throw_trampoline (&info, FALSE, TRUE, TRUE, FALSE, "llvm_throw_corlib_exception_abs_trampoline", aot);
1007         tramps = g_slist_prepend (tramps, info);
1008
1009         get_throw_trampoline (&info, FALSE, TRUE, TRUE, TRUE, "llvm_resume_unwind_trampoline", FALSE);
1010         tramps = g_slist_prepend (tramps, info);
1011
1012         return tramps;
1013 }
1014
1015 void
1016 mono_arch_exceptions_init (void)
1017 {
1018         GSList *tramps, *l;
1019         gpointer tramp;
1020
1021         if (mono_aot_only) {
1022                 throw_pending_exception = mono_aot_get_trampoline ("throw_pending_exception");
1023                 tramp = mono_aot_get_trampoline ("llvm_throw_corlib_exception_trampoline");
1024                 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
1025                 tramp = mono_aot_get_trampoline ("llvm_throw_corlib_exception_abs_trampoline");
1026                 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
1027                 tramp = mono_aot_get_trampoline ("llvm_resume_unwind_trampoline");
1028                 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
1029         } else {
1030                 /* Call this to avoid initialization races */
1031                 throw_pending_exception = mono_arch_get_throw_pending_exception (NULL, FALSE);
1032
1033                 tramps = mono_amd64_get_exception_trampolines (FALSE);
1034                 for (l = tramps; l; l = l->next) {
1035                         MonoTrampInfo *info = l->data;
1036
1037                         mono_register_jit_icall (info->code, g_strdup (info->name), NULL, TRUE);
1038                         mono_tramp_info_register (info);
1039                 }
1040                 g_slist_free (tramps);
1041         }
1042 }
1043
1044 #ifdef TARGET_WIN32
1045
1046 /*
1047  * The mono_arch_unwindinfo* methods are used to build and add
1048  * function table info for each emitted method from mono.  On Winx64
1049  * the seh handler will not be called if the mono methods are not
1050  * added to the function table.
1051  *
1052  * We should not need to add non-volatile register info to the
1053  * table since mono stores that info elsewhere. (Except for the register
1054  * used for the fp.)
1055  */
1056
1057 #define MONO_MAX_UNWIND_CODES 22
1058
1059 typedef union _UNWIND_CODE {
1060     struct {
1061         guchar CodeOffset;
1062         guchar UnwindOp : 4;
1063         guchar OpInfo   : 4;
1064     };
1065     gushort FrameOffset;
1066 } UNWIND_CODE, *PUNWIND_CODE;
1067
1068 typedef struct _UNWIND_INFO {
1069         guchar Version       : 3;
1070         guchar Flags         : 5;
1071         guchar SizeOfProlog;
1072         guchar CountOfCodes;
1073         guchar FrameRegister : 4;
1074         guchar FrameOffset   : 4;
1075         /* custom size for mono allowing for mono allowing for*/
1076         /*UWOP_PUSH_NONVOL ebp offset = 21*/
1077         /*UWOP_ALLOC_LARGE : requires 2 or 3 offset = 20*/
1078         /*UWOP_SET_FPREG : requires 2 offset = 17*/
1079         /*UWOP_PUSH_NONVOL offset = 15-0*/
1080         UNWIND_CODE UnwindCode[MONO_MAX_UNWIND_CODES];
1081
1082 /*      UNWIND_CODE MoreUnwindCode[((CountOfCodes + 1) & ~1) - 1];
1083  *      union {
1084  *          OPTIONAL ULONG ExceptionHandler;
1085  *          OPTIONAL ULONG FunctionEntry;
1086  *      };
1087  *      OPTIONAL ULONG ExceptionData[]; */
1088 } UNWIND_INFO, *PUNWIND_INFO;
1089
1090 typedef struct
1091 {
1092         RUNTIME_FUNCTION runtimeFunction;
1093         UNWIND_INFO unwindInfo;
1094 } MonoUnwindInfo, *PMonoUnwindInfo;
1095
1096 static void
1097 mono_arch_unwindinfo_create (gpointer* monoui)
1098 {
1099         PMonoUnwindInfo newunwindinfo;
1100         *monoui = newunwindinfo = g_new0 (MonoUnwindInfo, 1);
1101         newunwindinfo->unwindInfo.Version = 1;
1102 }
1103
1104 void
1105 mono_arch_unwindinfo_add_push_nonvol (gpointer* monoui, gpointer codebegin, gpointer nextip, guchar reg )
1106 {
1107         PMonoUnwindInfo unwindinfo;
1108         PUNWIND_CODE unwindcode;
1109         guchar codeindex;
1110         if (!*monoui)
1111                 mono_arch_unwindinfo_create (monoui);
1112
1113         unwindinfo = (MonoUnwindInfo*)*monoui;
1114
1115         if (unwindinfo->unwindInfo.CountOfCodes >= MONO_MAX_UNWIND_CODES)
1116                 g_error ("Larger allocation needed for the unwind information.");
1117
1118         codeindex = MONO_MAX_UNWIND_CODES - (++unwindinfo->unwindInfo.CountOfCodes);
1119         unwindcode = &unwindinfo->unwindInfo.UnwindCode[codeindex];
1120         unwindcode->UnwindOp = 0; /*UWOP_PUSH_NONVOL*/
1121         unwindcode->CodeOffset = (((guchar*)nextip)-((guchar*)codebegin));
1122         unwindcode->OpInfo = reg;
1123
1124         if (unwindinfo->unwindInfo.SizeOfProlog >= unwindcode->CodeOffset)
1125                 g_error ("Adding unwind info in wrong order.");
1126
1127         unwindinfo->unwindInfo.SizeOfProlog = unwindcode->CodeOffset;
1128 }
1129
1130 void
1131 mono_arch_unwindinfo_add_set_fpreg (gpointer* monoui, gpointer codebegin, gpointer nextip, guchar reg )
1132 {
1133         PMonoUnwindInfo unwindinfo;
1134         PUNWIND_CODE unwindcode;
1135         guchar codeindex;
1136         if (!*monoui)
1137                 mono_arch_unwindinfo_create (monoui);
1138
1139         unwindinfo = (MonoUnwindInfo*)*monoui;
1140
1141         if (unwindinfo->unwindInfo.CountOfCodes + 1 >= MONO_MAX_UNWIND_CODES)
1142                 g_error ("Larger allocation needed for the unwind information.");
1143
1144         codeindex = MONO_MAX_UNWIND_CODES - (unwindinfo->unwindInfo.CountOfCodes += 2);
1145         unwindcode = &unwindinfo->unwindInfo.UnwindCode[codeindex];
1146         unwindcode->FrameOffset = 0; /*Assuming no frame pointer offset for mono*/
1147         unwindcode++;
1148         unwindcode->UnwindOp = 3; /*UWOP_SET_FPREG*/
1149         unwindcode->CodeOffset = (((guchar*)nextip)-((guchar*)codebegin));
1150         unwindcode->OpInfo = reg;
1151
1152         unwindinfo->unwindInfo.FrameRegister = reg;
1153
1154         if (unwindinfo->unwindInfo.SizeOfProlog >= unwindcode->CodeOffset)
1155                 g_error ("Adding unwind info in wrong order.");
1156
1157         unwindinfo->unwindInfo.SizeOfProlog = unwindcode->CodeOffset;
1158 }
1159
1160 void
1161 mono_arch_unwindinfo_add_alloc_stack (gpointer* monoui, gpointer codebegin, gpointer nextip, guint size )
1162 {
1163         PMonoUnwindInfo unwindinfo;
1164         PUNWIND_CODE unwindcode;
1165         guchar codeindex;
1166         guchar codesneeded;
1167         if (!*monoui)
1168                 mono_arch_unwindinfo_create (monoui);
1169
1170         unwindinfo = (MonoUnwindInfo*)*monoui;
1171
1172         if (size < 0x8)
1173                 g_error ("Stack allocation must be equal to or greater than 0x8.");
1174
1175         if (size <= 0x80)
1176                 codesneeded = 1;
1177         else if (size <= 0x7FFF8)
1178                 codesneeded = 2;
1179         else
1180                 codesneeded = 3;
1181
1182         if (unwindinfo->unwindInfo.CountOfCodes + codesneeded > MONO_MAX_UNWIND_CODES)
1183                 g_error ("Larger allocation needed for the unwind information.");
1184
1185         codeindex = MONO_MAX_UNWIND_CODES - (unwindinfo->unwindInfo.CountOfCodes += codesneeded);
1186         unwindcode = &unwindinfo->unwindInfo.UnwindCode[codeindex];
1187
1188         if (codesneeded == 1) {
1189                 /*The size of the allocation is
1190                   (the number in the OpInfo member) times 8 plus 8*/
1191                 unwindcode->OpInfo = (size - 8)/8;
1192                 unwindcode->UnwindOp = 2; /*UWOP_ALLOC_SMALL*/
1193         }
1194         else {
1195                 if (codesneeded == 3) {
1196                         /*the unscaled size of the allocation is recorded
1197                           in the next two slots in little-endian format*/
1198                         *((unsigned int*)(&unwindcode->FrameOffset)) = size;
1199                         unwindcode += 2;
1200                         unwindcode->OpInfo = 1;
1201                 }
1202                 else {
1203                         /*the size of the allocation divided by 8
1204                           is recorded in the next slot*/
1205                         unwindcode->FrameOffset = size/8;
1206                         unwindcode++;
1207                         unwindcode->OpInfo = 0;
1208
1209                 }
1210                 unwindcode->UnwindOp = 1; /*UWOP_ALLOC_LARGE*/
1211         }
1212
1213         unwindcode->CodeOffset = (((guchar*)nextip)-((guchar*)codebegin));
1214
1215         if (unwindinfo->unwindInfo.SizeOfProlog >= unwindcode->CodeOffset)
1216                 g_error ("Adding unwind info in wrong order.");
1217
1218         unwindinfo->unwindInfo.SizeOfProlog = unwindcode->CodeOffset;
1219 }
1220
1221 guint
1222 mono_arch_unwindinfo_get_size (gpointer monoui)
1223 {
1224         PMonoUnwindInfo unwindinfo;
1225         if (!monoui)
1226                 return 0;
1227
1228         unwindinfo = (MonoUnwindInfo*)monoui;
1229         return (8 + sizeof (MonoUnwindInfo)) -
1230                 (sizeof (UNWIND_CODE) * (MONO_MAX_UNWIND_CODES - unwindinfo->unwindInfo.CountOfCodes));
1231 }
1232
1233 static PRUNTIME_FUNCTION
1234 MONO_GET_RUNTIME_FUNCTION_CALLBACK ( DWORD64 ControlPc, IN PVOID Context )
1235 {
1236         MonoJitInfo *ji;
1237         guint64 pos;
1238         PMonoUnwindInfo targetinfo;
1239         MonoDomain *domain = mono_domain_get ();
1240
1241         ji = mini_jit_info_table_find (domain, (char*)ControlPc, NULL);
1242         if (!ji)
1243                 return 0;
1244
1245         pos = (guint64)(((char*)ji->code_start) + ji->code_size);
1246
1247         targetinfo = (PMonoUnwindInfo)ALIGN_TO (pos, 8);
1248
1249         targetinfo->runtimeFunction.UnwindData = ((DWORD64)&targetinfo->unwindInfo) - ((DWORD64)Context);
1250
1251         return &targetinfo->runtimeFunction;
1252 }
1253
1254 void
1255 mono_arch_unwindinfo_install_unwind_info (gpointer* monoui, gpointer code, guint code_size)
1256 {
1257         PMonoUnwindInfo unwindinfo, targetinfo;
1258         guchar codecount;
1259         guint64 targetlocation;
1260         if (!*monoui)
1261                 return;
1262
1263         unwindinfo = (MonoUnwindInfo*)*monoui;
1264         targetlocation = (guint64)&(((guchar*)code)[code_size]);
1265         targetinfo = (PMonoUnwindInfo) ALIGN_TO(targetlocation, 8);
1266
1267         unwindinfo->runtimeFunction.EndAddress = code_size;
1268         unwindinfo->runtimeFunction.UnwindData = ((guchar*)&targetinfo->unwindInfo) - ((guchar*)code);
1269
1270         memcpy (targetinfo, unwindinfo, sizeof (MonoUnwindInfo) - (sizeof (UNWIND_CODE) * MONO_MAX_UNWIND_CODES));
1271
1272         codecount = unwindinfo->unwindInfo.CountOfCodes;
1273         if (codecount) {
1274                 memcpy (&targetinfo->unwindInfo.UnwindCode[0], &unwindinfo->unwindInfo.UnwindCode[MONO_MAX_UNWIND_CODES-codecount],
1275                         sizeof (UNWIND_CODE) * unwindinfo->unwindInfo.CountOfCodes);
1276         }
1277
1278         g_free (unwindinfo);
1279         *monoui = 0;
1280
1281         RtlInstallFunctionTableCallback (((DWORD64)code) | 0x3, (DWORD64)code, code_size, MONO_GET_RUNTIME_FUNCTION_CALLBACK, code, NULL);
1282 }
1283
1284 #endif
1285
1286 #if MONO_SUPPORT_TASKLETS
1287 MonoContinuationRestore
1288 mono_tasklets_arch_restore (void)
1289 {
1290         static guint8* saved = NULL;
1291         guint8 *code, *start;
1292         int cont_reg = AMD64_R9; /* register usable on both call conventions */
1293         const guint kMaxCodeSize = NACL_SIZE (64, 128);
1294
1295
1296         if (saved)
1297                 return (MonoContinuationRestore)saved;
1298         code = start = mono_global_codeman_reserve (kMaxCodeSize);
1299         /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1300         /* cont is in AMD64_ARG_REG1 ($rcx or $rdi)
1301          * state is in AMD64_ARG_REG2 ($rdx or $rsi)
1302          * lmf_addr is in AMD64_ARG_REG3 ($r8 or $rdx)
1303          * We move cont to cont_reg since we need both rcx and rdi for the copy
1304          * state is moved to $rax so it's setup as the return value and we can overwrite $rsi
1305          */
1306         amd64_mov_reg_reg (code, cont_reg, MONO_AMD64_ARG_REG1, 8);
1307         amd64_mov_reg_reg (code, AMD64_RAX, MONO_AMD64_ARG_REG2, 8);
1308         /* setup the copy of the stack */
1309         amd64_mov_reg_membase (code, AMD64_RCX, cont_reg, MONO_STRUCT_OFFSET (MonoContinuation, stack_used_size), sizeof (int));
1310         amd64_shift_reg_imm (code, X86_SHR, AMD64_RCX, 3);
1311         x86_cld (code);
1312         amd64_mov_reg_membase (code, AMD64_RSI, cont_reg, MONO_STRUCT_OFFSET (MonoContinuation, saved_stack), sizeof (gpointer));
1313         amd64_mov_reg_membase (code, AMD64_RDI, cont_reg, MONO_STRUCT_OFFSET (MonoContinuation, return_sp), sizeof (gpointer));
1314         amd64_prefix (code, X86_REP_PREFIX);
1315         amd64_movsl (code);
1316
1317         /* now restore the registers from the LMF */
1318         NOT_IMPLEMENTED;
1319         amd64_mov_reg_membase (code, AMD64_RCX, cont_reg, MONO_STRUCT_OFFSET (MonoContinuation, lmf), 8);
1320         amd64_mov_reg_membase (code, AMD64_RSP, AMD64_RCX, MONO_STRUCT_OFFSET (MonoLMF, rsp), 8);
1321
1322         /* restore the lmf chain */
1323         /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1324         x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1325
1326         /* state is already in rax */
1327         amd64_jump_membase (code, cont_reg, MONO_STRUCT_OFFSET (MonoContinuation, return_ip));
1328         g_assert ((code - start) <= kMaxCodeSize);
1329
1330         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
1331         mono_arch_flush_icache (start, code - start);
1332         mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
1333
1334         saved = start;
1335         return (MonoContinuationRestore)saved;
1336 }
1337 #endif
1338
1339 /*
1340  * mono_arch_setup_resume_sighandler_ctx:
1341  *
1342  *   Setup CTX so execution continues at FUNC.
1343  */
1344 void
1345 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1346 {
1347         /*
1348          * When resuming from a signal handler, the stack should be misaligned, just like right after
1349          * a call.
1350          */
1351         if ((((guint64)MONO_CONTEXT_GET_SP (ctx)) % 16) == 0)
1352                 MONO_CONTEXT_SET_SP (ctx, (guint64)MONO_CONTEXT_GET_SP (ctx) - 8);
1353         MONO_CONTEXT_SET_IP (ctx, func);
1354 }