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 #if _WIN32_WINNT < 0x0501
  14 /* Required for Vectored Exception Handling. */
  15 #undef _WIN32_WINNT
  16 #define _WIN32_WINNT 0x0501
  17 #endif /* _WIN32_WINNT < 0x0501 */
  18
  19 #include <glib.h>
  20 #include <signal.h>
  21 #include <string.h>
  22 #ifdef HAVE_UCONTEXT_H
  23 #include <ucontext.h>
  24 #endif
  25
  26 #include <mono/arch/amd64/amd64-codegen.h>
  27 #include <mono/metadata/appdomain.h>
  28 #include <mono/metadata/tabledefs.h>
  29 #include <mono/metadata/threads.h>
  30 #include <mono/metadata/threads-types.h>
  31 #include <mono/metadata/debug-helpers.h>
  32 #include <mono/metadata/exception.h>
  33 #include <mono/metadata/gc-internal.h>
  34 #include <mono/metadata/mono-debug.h>
  35 #include <mono/utils/mono-mmap.h>
  36
  37 #include "mini.h"
  38 #include "mini-amd64.h"
  39 #include "tasklets.h"
  40
  41 #define ALIGN_TO(val,align) (((val) + ((align) - 1)) & ~((align) - 1))
  42
  43 #ifdef TARGET_WIN32
  44 static MonoW32ExceptionHandler fpe_handler;
  45 static MonoW32ExceptionHandler ill_handler;
  46 static MonoW32ExceptionHandler segv_handler;
  47
  48 LPTOP_LEVEL_EXCEPTION_FILTER mono_old_win_toplevel_exception_filter;
  49 void *mono_win_vectored_exception_handle;
  50 extern gboolean mono_win_chained_exception_needs_run;
  51
  52 #define W32_SEH_HANDLE_EX(_ex) \
  53         if (_ex##_handler) _ex##_handler(0, ep, sctx)
  54
  55 LONG CALLBACK seh_unhandled_exception_filter(EXCEPTION_POINTERS* ep)
  56 {
  57 #ifndef MONO_CROSS_COMPILE
  58         if (mono_old_win_toplevel_exception_filter) {
  59                 return (*mono_old_win_toplevel_exception_filter)(ep);
  60         }
  61 #endif
  62
  63         mono_handle_native_sigsegv (SIGSEGV, NULL);
  64
  65         return EXCEPTION_CONTINUE_SEARCH;
  66 }
  67
  68 /*
  69  * Unhandled Exception Filter
  70  * Top-level per-process exception handler.
  71  */
  72 LONG CALLBACK seh_vectored_exception_handler(EXCEPTION_POINTERS* ep)
  73 {
  74         EXCEPTION_RECORD* er;
  75         CONTEXT* ctx;
  76         MonoContext* sctx;
  77         LONG res;
  78
  79         mono_win_chained_exception_needs_run = FALSE;
  80         res = EXCEPTION_CONTINUE_EXECUTION;
  81
  82         er = ep->ExceptionRecord;
  83         ctx = ep->ContextRecord;
  84         sctx = g_malloc(sizeof(MonoContext));
  85
  86         /* Copy Win32 context to UNIX style context */
  87         sctx->rax = ctx->Rax;
  88         sctx->rbx = ctx->Rbx;
  89         sctx->rcx = ctx->Rcx;
  90         sctx->rdx = ctx->Rdx;
  91         sctx->rbp = ctx->Rbp;
  92         sctx->rsp = ctx->Rsp;
  93         sctx->rsi = ctx->Rsi;
  94         sctx->rdi = ctx->Rdi;
  95         sctx->rip = ctx->Rip;
  96         sctx->r12 = ctx->R12;
  97         sctx->r13 = ctx->R13;
  98         sctx->r14 = ctx->R14;
  99         sctx->r15 = ctx->R15;
 100
 101         switch (er->ExceptionCode) {
 102         case EXCEPTION_ACCESS_VIOLATION:
 103                 W32_SEH_HANDLE_EX(segv);
 104                 break;
 105         case EXCEPTION_ILLEGAL_INSTRUCTION:
 106                 W32_SEH_HANDLE_EX(ill);
 107                 break;
 108         case EXCEPTION_INT_DIVIDE_BY_ZERO:
 109         case EXCEPTION_INT_OVERFLOW:
 110         case EXCEPTION_FLT_DIVIDE_BY_ZERO:
 111         case EXCEPTION_FLT_OVERFLOW:
 112         case EXCEPTION_FLT_UNDERFLOW:
 113         case EXCEPTION_FLT_INEXACT_RESULT:
 114                 W32_SEH_HANDLE_EX(fpe);
 115                 break;
 116         default:
 117                 break;
 118         }
 119
 120         if (mono_win_chained_exception_needs_run) {
 121                 /* Don't copy context back if we chained exception
 122                 * as the handler may have modfied the EXCEPTION_POINTERS
 123                 * directly. We don't pass sigcontext to chained handlers.
 124                 * Return continue search so the UnhandledExceptionFilter
 125                 * can correctly chain the exception.
 126                 */
 127                 res = EXCEPTION_CONTINUE_SEARCH;
 128         } else {
 129                 /* Copy context back */
 130                 /* Nonvolatile */
 131                 ctx->Rsp = sctx->rsp;
 132                 ctx->Rdi = sctx->rdi;
 133                 ctx->Rsi = sctx->rsi;
 134                 ctx->Rbx = sctx->rbx;
 135                 ctx->Rbp = sctx->rbp;
 136                 ctx->R12 = sctx->r12;
 137                 ctx->R13 = sctx->r13;
 138                 ctx->R14 = sctx->r14;
 139                 ctx->R15 = sctx->r15;
 140                 ctx->Rip = sctx->rip;
 141
 142                 /* Volatile But should not matter?*/
 143                 ctx->Rax = sctx->rax;
 144                 ctx->Rcx = sctx->rcx;
 145                 ctx->Rdx = sctx->rdx;
 146         }
 147
 148         /* TODO: Find right place to free this in stack overflow case */
 149         if (er->ExceptionCode != EXCEPTION_STACK_OVERFLOW)
 150                 g_free (sctx);
 151
 152         return res;
 153 }
 154
 155 void win32_seh_init()
 156 {
 157         mono_old_win_toplevel_exception_filter = SetUnhandledExceptionFilter(seh_unhandled_exception_filter);
 158         mono_win_vectored_exception_handle = AddVectoredExceptionHandler (1, seh_vectored_exception_handler);
 159 }
 160
 161 void win32_seh_cleanup()
 162 {
 163         if (mono_old_win_toplevel_exception_filter) SetUnhandledExceptionFilter(mono_old_win_toplevel_exception_filter);
 164
 165         guint32 ret = 0;
 166
 167         ret = RemoveVectoredExceptionHandler (mono_win_vectored_exception_handle);
 168         g_assert (ret);
 169 }
 170
 171 void win32_seh_set_handler(int type, MonoW32ExceptionHandler handler)
 172 {
 173         switch (type) {
 174         case SIGFPE:
 175                 fpe_handler = handler;
 176                 break;
 177         case SIGILL:
 178                 ill_handler = handler;
 179                 break;
 180         case SIGSEGV:
 181                 segv_handler = handler;
 182                 break;
 183         default:
 184                 break;
 185         }
 186 }
 187
 188 #endif /* TARGET_WIN32 */
 189
 190 /*
 191  * mono_arch_get_restore_context:
 192  *
 193  * Returns a pointer to a method which restores a previously saved sigcontext.
 194  */
 195 gpointer
 196 mono_arch_get_restore_context (MonoTrampInfo **info, gboolean aot)
 197 {
 198         guint8 *start = NULL;
 199         guint8 *code;
 200         MonoJumpInfo *ji = NULL;
 201         GSList *unwind_ops = NULL;
 202
 203         /* restore_contect (MonoContext *ctx) */
 204
 205         start = code = mono_global_codeman_reserve (256);
 206
 207         amd64_mov_reg_reg (code, AMD64_R11, AMD64_ARG_REG1, 8);
 208
 209         /* Restore all registers except %rip and %r11 */
 210         amd64_mov_reg_membase (code, AMD64_RAX, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rax), 8);
 211         amd64_mov_reg_membase (code, AMD64_RCX, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rcx), 8);
 212         amd64_mov_reg_membase (code, AMD64_RDX, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rdx), 8);
 213         amd64_mov_reg_membase (code, AMD64_RBX, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rbx), 8);
 214         amd64_mov_reg_membase (code, AMD64_RBP, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rbp), 8);
 215         amd64_mov_reg_membase (code, AMD64_RSI, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rsi), 8);
 216         amd64_mov_reg_membase (code, AMD64_RDI, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rdi), 8);
 217         //amd64_mov_reg_membase (code, AMD64_R8, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r8), 8);
 218         //amd64_mov_reg_membase (code, AMD64_R9, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r9), 8);
 219         //amd64_mov_reg_membase (code, AMD64_R10, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r10), 8);
 220         amd64_mov_reg_membase (code, AMD64_R12, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r12), 8);
 221         amd64_mov_reg_membase (code, AMD64_R13, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r13), 8);
 222         amd64_mov_reg_membase (code, AMD64_R14, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r14), 8);
 223 #if !defined(__native_client_codegen__)
 224         amd64_mov_reg_membase (code, AMD64_R15, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, r15), 8);
 225 #endif
 226
 227         /*
 228          * The context resides on the stack, in the stack frame of the
 229          * caller of this function.  The stack pointer that we need to
 230          * restore is potentially many stack frames higher up, so the
 231          * distance between them can easily be more than the red zone
 232          * size.  Hence the stack pointer can be restored only after
 233          * we have finished loading everything from the context.
 234          */
 235         amd64_mov_reg_membase (code, AMD64_R8, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rsp), 8);
 236         amd64_mov_reg_membase (code, AMD64_R11, AMD64_R11,  G_STRUCT_OFFSET (MonoContext, rip), 8);
 237         amd64_mov_reg_reg (code, AMD64_RSP, AMD64_R8, 8);
 238
 239         /* jump to the saved IP */
 240         amd64_jump_reg (code, AMD64_R11);
 241
 242         nacl_global_codeman_validate(&start, 256, &code);
 243
 244         mono_arch_flush_icache (start, code - start);
 245
 246         if (info)
 247                 *info = mono_tramp_info_create ("restore_context", start, code - start, ji, unwind_ops);
 248
 249         return start;
 250 }
 251
 252 /*
 253  * mono_arch_get_call_filter:
 254  *
 255  * Returns a pointer to a method which calls an exception filter. We
 256  * also use this function to call finally handlers (we pass NULL as
 257  * @exc object in this case).
 258  */
 259 gpointer
 260 mono_arch_get_call_filter (MonoTrampInfo **info, gboolean aot)
 261 {
 262         guint8 *start;
 263         int i;
 264         guint8 *code;
 265         guint32 pos;
 266         MonoJumpInfo *ji = NULL;
 267         GSList *unwind_ops = NULL;
 268         const guint kMaxCodeSize = NACL_SIZE (128, 256);
 269
 270         start = code = mono_global_codeman_reserve (kMaxCodeSize);
 271
 272         /* call_filter (MonoContext *ctx, unsigned long eip) */
 273         code = start;
 274
 275         /* Alloc new frame */
 276         amd64_push_reg (code, AMD64_RBP);
 277         amd64_mov_reg_reg (code, AMD64_RBP, AMD64_RSP, 8);
 278
 279         /* Save callee saved regs */
 280         pos = 0;
 281         for (i = 0; i < AMD64_NREG; ++i)
 282                 if (AMD64_IS_CALLEE_SAVED_REG (i)) {
 283                         amd64_push_reg (code, i);
 284                         pos += 8;
 285                 }
 286
 287         /* Save EBP */
 288         pos += 8;
 289         amd64_push_reg (code, AMD64_RBP);
 290
 291         /* Make stack misaligned, the call will make it aligned again */
 292         if (! (pos & 8))
 293                 amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 294
 295         /* set new EBP */
 296         amd64_mov_reg_membase (code, AMD64_RBP, AMD64_ARG_REG1, G_STRUCT_OFFSET (MonoContext, rbp), 8);
 297         /* load callee saved regs */
 298         amd64_mov_reg_membase (code, AMD64_RBX, AMD64_ARG_REG1, G_STRUCT_OFFSET (MonoContext, rbx), 8);
 299         amd64_mov_reg_membase (code, AMD64_R12, AMD64_ARG_REG1, G_STRUCT_OFFSET (MonoContext, r12), 8);
 300         amd64_mov_reg_membase (code, AMD64_R13, AMD64_ARG_REG1, G_STRUCT_OFFSET (MonoContext, r13), 8);
 301         amd64_mov_reg_membase (code, AMD64_R14, AMD64_ARG_REG1, G_STRUCT_OFFSET (MonoContext, r14), 8);
 302 #if !defined(__native_client_codegen__)
 303         amd64_mov_reg_membase (code, AMD64_R15, AMD64_ARG_REG1, G_STRUCT_OFFSET (MonoContext, r15), 8);
 304 #endif
 305 #ifdef TARGET_WIN32
 306         amd64_mov_reg_membase (code, AMD64_RDI, AMD64_ARG_REG1,  G_STRUCT_OFFSET (MonoContext, rdi), 8);
 307         amd64_mov_reg_membase (code, AMD64_RSI, AMD64_ARG_REG1,  G_STRUCT_OFFSET (MonoContext, rsi), 8);
 308 #endif
 309
 310         /* call the handler */
 311         amd64_call_reg (code, AMD64_ARG_REG2);
 312
 313         if (! (pos & 8))
 314                 amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 8);
 315
 316         /* restore RBP */
 317         amd64_pop_reg (code, AMD64_RBP);
 318
 319         /* Restore callee saved regs */
 320         for (i = AMD64_NREG; i >= 0; --i)
 321                 if (AMD64_IS_CALLEE_SAVED_REG (i))
 322                         amd64_pop_reg (code, i);
 323
 324         amd64_leave (code);
 325         amd64_ret (code);
 326
 327         g_assert ((code - start) < kMaxCodeSize);
 328
 329         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
 330
 331         mono_arch_flush_icache (start, code - start);
 332
 333         if (info)
 334                 *info = mono_tramp_info_create ("call_filter", start, code - start, ji, unwind_ops);
 335
 336         return start;
 337 }
 338
 339 /*
 340  * The first few arguments are dummy, to force the other arguments to be passed on
 341  * the stack, this avoids overwriting the argument registers in the throw trampoline.
 342  */
 343 void
 344 mono_amd64_throw_exception (guint64 dummy1, guint64 dummy2, guint64 dummy3, guint64 dummy4,
 345                                                         guint64 dummy5, guint64 dummy6,
 346                                                         mgreg_t *regs, mgreg_t rip,
 347                                                         MonoObject *exc, gboolean rethrow)
 348 {
 349         MonoContext ctx;
 350
 351         ctx.rsp = regs [AMD64_RSP];
 352         ctx.rip = rip;
 353         ctx.rbx = regs [AMD64_RBX];
 354         ctx.rbp = regs [AMD64_RBP];
 355         ctx.r12 = regs [AMD64_R12];
 356         ctx.r13 = regs [AMD64_R13];
 357         ctx.r14 = regs [AMD64_R14];
 358         ctx.r15 = regs [AMD64_R15];
 359         ctx.rdi = regs [AMD64_RDI];
 360         ctx.rsi = regs [AMD64_RSI];
 361         ctx.rax = regs [AMD64_RAX];
 362         ctx.rcx = regs [AMD64_RCX];
 363         ctx.rdx = regs [AMD64_RDX];
 364
 365         if (mono_object_isinst (exc, mono_defaults.exception_class)) {
 366                 MonoException *mono_ex = (MonoException*)exc;
 367                 if (!rethrow)
 368                         mono_ex->stack_trace = NULL;
 369         }
 370
 371         /* adjust eip so that it point into the call instruction */
 372         ctx.rip -= 1;
 373
 374         mono_handle_exception (&ctx, exc);
 375         mono_restore_context (&ctx);
 376         g_assert_not_reached ();
 377 }
 378
 379 void
 380 mono_amd64_throw_corlib_exception (guint64 dummy1, guint64 dummy2, guint64 dummy3, guint64 dummy4,
 381                                                                    guint64 dummy5, guint64 dummy6,
 382                                                                    mgreg_t *regs, mgreg_t rip,
 383                                                                    guint32 ex_token_index, gint64 pc_offset)
 384 {
 385         guint32 ex_token = MONO_TOKEN_TYPE_DEF | ex_token_index;
 386         MonoException *ex;
 387
 388         ex = mono_exception_from_token (mono_defaults.exception_class->image, ex_token);
 389
 390         rip -= pc_offset;
 391
 392         /* Negate the ip adjustment done in mono_amd64_throw_exception () */
 393         rip += 1;
 394
 395         mono_amd64_throw_exception (dummy1, dummy2, dummy3, dummy4, dummy5, dummy6, regs, rip, (MonoObject*)ex, FALSE);
 396 }
 397
 398 static void
 399 mono_amd64_resume_unwind (guint64 dummy1, guint64 dummy2, guint64 dummy3, guint64 dummy4,
 400                                                   guint64 dummy5, guint64 dummy6,
 401                                                   mgreg_t *regs, mgreg_t rip,
 402                                                   guint32 dummy7, gint64 dummy8)
 403 {
 404         /* Only the register parameters are valid */
 405         MonoContext ctx;
 406
 407         ctx.rsp = regs [AMD64_RSP];
 408         ctx.rip = rip;
 409         ctx.rbx = regs [AMD64_RBX];
 410         ctx.rbp = regs [AMD64_RBP];
 411         ctx.r12 = regs [AMD64_R12];
 412         ctx.r13 = regs [AMD64_R13];
 413         ctx.r14 = regs [AMD64_R14];
 414         ctx.r15 = regs [AMD64_R15];
 415         ctx.rdi = regs [AMD64_RDI];
 416         ctx.rsi = regs [AMD64_RSI];
 417         ctx.rax = regs [AMD64_RAX];
 418         ctx.rcx = regs [AMD64_RCX];
 419         ctx.rdx = regs [AMD64_RDX];
 420
 421         mono_resume_unwind (&ctx);
 422 }
 423
 424 /*
 425  * get_throw_trampoline:
 426  *
 427  *  Generate a call to mono_amd64_throw_exception/
 428  * mono_amd64_throw_corlib_exception.
 429  */
 430 static gpointer
 431 get_throw_trampoline (MonoTrampInfo **info, gboolean rethrow, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, const char *tramp_name, gboolean aot)
 432 {
 433         guint8* start;
 434         guint8 *code;
 435         MonoJumpInfo *ji = NULL;
 436         GSList *unwind_ops = NULL;
 437         int i, stack_size, arg_offsets [16], regs_offset, dummy_stack_space;
 438         const guint kMaxCodeSize = NACL_SIZE (256, 512);
 439
 440 #ifdef TARGET_WIN32
 441         dummy_stack_space = 6 * sizeof(mgreg_t);        /* Windows expects stack space allocated for all 6 dummy args. */
 442 #else
 443         dummy_stack_space = 0;
 444 #endif
 445
 446         start = code = mono_global_codeman_reserve (kMaxCodeSize);
 447
 448         /* The stack is unaligned on entry */
 449         stack_size = 192 + 8 + dummy_stack_space;
 450
 451         code = start;
 452
 453         if (info)
 454                 unwind_ops = mono_arch_get_cie_program ();
 455
 456         /* Alloc frame */
 457         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, stack_size);
 458         if (info)
 459                 mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 8);
 460
 461         /*
 462          * To hide linux/windows calling convention differences, we pass all arguments on
 463          * the stack by passing 6 dummy values in registers.
 464          */
 465
 466         arg_offsets [0] = dummy_stack_space + 0;
 467         arg_offsets [1] = dummy_stack_space + sizeof(mgreg_t);
 468         arg_offsets [2] = dummy_stack_space + sizeof(mgreg_t) * 2;
 469         arg_offsets [3] = dummy_stack_space + sizeof(mgreg_t) * 3;
 470         regs_offset = dummy_stack_space + sizeof(mgreg_t) * 4;
 471
 472         /* Save registers */
 473         for (i = 0; i < AMD64_NREG; ++i)
 474                 if (i != AMD64_RSP)
 475                         amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (i * sizeof(mgreg_t)), i, sizeof(mgreg_t));
 476         /* Save RSP */
 477         amd64_lea_membase (code, AMD64_RAX, AMD64_RSP, stack_size + sizeof(mgreg_t));
 478         amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (AMD64_RSP * sizeof(mgreg_t)), X86_EAX, sizeof(mgreg_t));
 479         /* Set arg1 == regs */
 480         amd64_lea_membase (code, AMD64_RAX, AMD64_RSP, regs_offset);
 481         amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [0], AMD64_RAX, sizeof(mgreg_t));
 482         /* Set arg2 == eip */
 483         if (llvm_abs)
 484                 amd64_alu_reg_reg (code, X86_XOR, AMD64_RAX, AMD64_RAX);
 485         else
 486                 amd64_mov_reg_membase (code, AMD64_RAX, AMD64_RSP, stack_size, sizeof(mgreg_t));
 487         amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [1], AMD64_RAX, sizeof(mgreg_t));
 488         /* Set arg3 == exc/ex_token_index */
 489         if (resume_unwind)
 490                 amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [2], 0, sizeof(mgreg_t));
 491         else
 492                 amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [2], AMD64_ARG_REG1, sizeof(mgreg_t));
 493         /* Set arg4 == rethrow/pc offset */
 494         if (resume_unwind) {
 495                 amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [3], 0, sizeof(mgreg_t));
 496         } else if (corlib) {
 497                 amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [3], AMD64_ARG_REG2, sizeof(mgreg_t));
 498                 if (llvm_abs)
 499                         /*
 500                          * The caller is LLVM code which passes the absolute address not a pc offset,
 501                          * so compensate by passing 0 as 'rip' and passing the negated abs address as
 502                          * the pc offset.
 503                          */
 504                         amd64_neg_membase (code, AMD64_RSP, arg_offsets [3]);
 505         } else {
 506                 amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [3], rethrow, sizeof(mgreg_t));
 507         }
 508
 509         if (aot) {
 510                 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");
 511                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 512         } else {
 513                 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));
 514         }
 515         amd64_call_reg (code, AMD64_R11);
 516         amd64_breakpoint (code);
 517
 518         mono_arch_flush_icache (start, code - start);
 519
 520         g_assert ((code - start) < kMaxCodeSize);
 521
 522         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
 523
 524         if (info)
 525                 *info = mono_tramp_info_create (tramp_name, start, code - start, ji, unwind_ops);
 526
 527         return start;
 528 }
 529
 530 /**
 531  * mono_arch_get_throw_exception:
 532  *
 533  * Returns a function pointer which can be used to raise
 534  * exceptions. The returned function has the following
 535  * signature: void (*func) (MonoException *exc);
 536  *
 537  */
 538 gpointer
 539 mono_arch_get_throw_exception (MonoTrampInfo **info, gboolean aot)
 540 {
 541         return get_throw_trampoline (info, FALSE, FALSE, FALSE, FALSE, "throw_exception", aot);
 542 }
 543
 544 gpointer
 545 mono_arch_get_rethrow_exception (MonoTrampInfo **info, gboolean aot)
 546 {
 547         return get_throw_trampoline (info, TRUE, FALSE, FALSE, FALSE, "rethrow_exception", aot);
 548 }
 549
 550 /**
 551  * mono_arch_get_throw_corlib_exception:
 552  *
 553  * Returns a function pointer which can be used to raise
 554  * corlib exceptions. The returned function has the following
 555  * signature: void (*func) (guint32 ex_token, guint32 offset);
 556  * Here, offset is the offset which needs to be substracted from the caller IP
 557  * to get the IP of the throw. Passing the offset has the advantage that it
 558  * needs no relocations in the caller.
 559  */
 560 gpointer
 561 mono_arch_get_throw_corlib_exception (MonoTrampInfo **info, gboolean aot)
 562 {
 563         return get_throw_trampoline (info, FALSE, TRUE, FALSE, FALSE, "throw_corlib_exception", aot);
 564 }
 565
 566 /*
 567  * mono_arch_find_jit_info:
 568  *
 569  * This function is used to gather information from @ctx, and store it in @frame_info.
 570  * It unwinds one stack frame, and stores the resulting context into @new_ctx. @lmf
 571  * is modified if needed.
 572  * Returns TRUE on success, FALSE otherwise.
 573  */
 574 gboolean
 575 mono_arch_find_jit_info (MonoDomain *domain, MonoJitTlsData *jit_tls,
 576                                                          MonoJitInfo *ji, MonoContext *ctx,
 577                                                          MonoContext *new_ctx, MonoLMF **lmf,
 578                                                          mgreg_t **save_locations,
 579                                                          StackFrameInfo *frame)
 580 {
 581         gpointer ip = MONO_CONTEXT_GET_IP (ctx);
 582
 583         memset (frame, 0, sizeof (StackFrameInfo));
 584         frame->ji = ji;
 585
 586         *new_ctx = *ctx;
 587
 588         if (ji != NULL) {
 589                 mgreg_t regs [MONO_MAX_IREGS + 1];
 590                 guint8 *cfa;
 591                 guint32 unwind_info_len;
 592                 guint8 *unwind_info;
 593
 594                 frame->type = FRAME_TYPE_MANAGED;
 595
 596                 if (ji->from_aot)
 597                         unwind_info = mono_aot_get_unwind_info (ji, &unwind_info_len);
 598                 else
 599                         unwind_info = mono_get_cached_unwind_info (ji->used_regs, &unwind_info_len);
 600
 601                 frame->unwind_info = unwind_info;
 602                 frame->unwind_info_len = unwind_info_len;
 603
 604                 /*
 605                 printf ("%s %p %p\n", ji->d.method->name, ji->code_start, ip);
 606                 mono_print_unwind_info (unwind_info, unwind_info_len);
 607                 */
 608
 609                 regs [AMD64_RAX] = new_ctx->rax;
 610                 regs [AMD64_RBX] = new_ctx->rbx;
 611                 regs [AMD64_RCX] = new_ctx->rcx;
 612                 regs [AMD64_RDX] = new_ctx->rdx;
 613                 regs [AMD64_RBP] = new_ctx->rbp;
 614                 regs [AMD64_RSP] = new_ctx->rsp;
 615                 regs [AMD64_RSI] = new_ctx->rsi;
 616                 regs [AMD64_RDI] = new_ctx->rdi;
 617                 regs [AMD64_RIP] = new_ctx->rip;
 618                 regs [AMD64_R12] = new_ctx->r12;
 619                 regs [AMD64_R13] = new_ctx->r13;
 620                 regs [AMD64_R14] = new_ctx->r14;
 621                 regs [AMD64_R15] = new_ctx->r15;
 622
 623                 mono_unwind_frame (unwind_info, unwind_info_len, ji->code_start,
 624                                                    (guint8*)ji->code_start + ji->code_size,
 625                                                    ip, regs, MONO_MAX_IREGS + 1,
 626                                                    save_locations, MONO_MAX_IREGS, &cfa);
 627
 628                 new_ctx->rax = regs [AMD64_RAX];
 629                 new_ctx->rbx = regs [AMD64_RBX];
 630                 new_ctx->rcx = regs [AMD64_RCX];
 631                 new_ctx->rdx = regs [AMD64_RDX];
 632                 new_ctx->rbp = regs [AMD64_RBP];
 633                 new_ctx->rsp = regs [AMD64_RSP];
 634                 new_ctx->rsi = regs [AMD64_RSI];
 635                 new_ctx->rdi = regs [AMD64_RDI];
 636                 new_ctx->rip = regs [AMD64_RIP];
 637                 new_ctx->r12 = regs [AMD64_R12];
 638                 new_ctx->r13 = regs [AMD64_R13];
 639                 new_ctx->r14 = regs [AMD64_R14];
 640                 new_ctx->r15 = regs [AMD64_R15];
 641
 642                 /* The CFA becomes the new SP value */
 643                 new_ctx->rsp = (mgreg_t)cfa;
 644
 645                 /* Adjust IP */
 646                 new_ctx->rip --;
 647
 648                 if (*lmf && ((*lmf) != jit_tls->first_lmf) && (MONO_CONTEXT_GET_SP (ctx) >= (gpointer)(*lmf)->rsp)) {
 649                         /* remove any unused lmf */
 650                         *lmf = (gpointer)(((guint64)(*lmf)->previous_lmf) & ~7);
 651                 }
 652
 653 #ifndef MONO_AMD64_NO_PUSHES
 654                 /* Pop arguments off the stack */
 655                 if (ji->has_arch_eh_info)
 656                         new_ctx->rsp += mono_jit_info_get_arch_eh_info (ji)->stack_size;
 657 #endif
 658
 659                 return TRUE;
 660         } else if (*lmf) {
 661                 guint64 rip;
 662
 663                 if (((guint64)(*lmf)->previous_lmf) & 2) {
 664                         /*
 665                          * This LMF entry is created by the soft debug code to mark transitions to
 666                          * managed code done during invokes.
 667                          */
 668                         MonoLMFExt *ext = (MonoLMFExt*)(*lmf);
 669
 670                         g_assert (ext->debugger_invoke);
 671
 672                         memcpy (new_ctx, &ext->ctx, sizeof (MonoContext));
 673
 674                         *lmf = (gpointer)(((guint64)(*lmf)->previous_lmf) & ~7);
 675
 676                         frame->type = FRAME_TYPE_DEBUGGER_INVOKE;
 677
 678                         return TRUE;
 679                 }
 680
 681                 if (((guint64)(*lmf)->previous_lmf) & 1) {
 682                         /* This LMF has the rip field set */
 683                         rip = (*lmf)->rip;
 684                 } else if ((*lmf)->rsp == 0) {
 685                         /* Top LMF entry */
 686                         return FALSE;
 687                 } else {
 688                         /*
 689                          * The rsp field is set just before the call which transitioned to native
 690                          * code. Obtain the rip from the stack.
 691                          */
 692                         rip = *(guint64*)((*lmf)->rsp - sizeof(mgreg_t));
 693                 }
 694
 695                 ji = mini_jit_info_table_find (domain, (gpointer)rip, NULL);
 696                 /*
 697                  * FIXME: ji == NULL can happen when a managed-to-native wrapper is interrupted
 698                  * in the soft debugger suspend code, since (*lmf)->rsp no longer points to the
 699                  * return address.
 700                  */
 701                 //g_assert (ji);
 702                 if (!ji)
 703                         return FALSE;
 704
 705                 /* Adjust IP */
 706                 rip --;
 707
 708                 frame->ji = ji;
 709                 frame->type = FRAME_TYPE_MANAGED_TO_NATIVE;
 710
 711                 new_ctx->rip = rip;
 712                 new_ctx->rbp = (*lmf)->rbp;
 713                 new_ctx->rsp = (*lmf)->rsp;
 714
 715                 if (((guint64)(*lmf)->previous_lmf) & 4) {
 716                         MonoLMFTramp *ext = (MonoLMFTramp*)(*lmf);
 717
 718                         /* Trampoline frame */
 719                         new_ctx->rbx = ext->regs [AMD64_RBX];
 720                         new_ctx->r12 = ext->regs [AMD64_R12];
 721                         new_ctx->r13 = ext->regs [AMD64_R13];
 722                         new_ctx->r14 = ext->regs [AMD64_R14];
 723                         new_ctx->r15 = ext->regs [AMD64_R15];
 724 #ifdef TARGET_WIN32
 725                         new_ctx->rdi = ext->regs [AMD64_RDI];
 726                         new_ctx->rsi = ext->regs [AMD64_RSI];
 727 #endif
 728                 } else {
 729                         /*
 730                          * The registers saved in the LMF will be restored using the normal unwind info,
 731                          * when the wrapper frame is processed.
 732                          */
 733                         new_ctx->rbx = 0;
 734                         new_ctx->r12 = 0;
 735                         new_ctx->r13 = 0;
 736                         new_ctx->r14 = 0;
 737                         new_ctx->r15 = 0;
 738 #ifdef TARGET_WIN32
 739                         new_ctx->rdi = 0;
 740                         new_ctx->rsi = 0;
 741 #endif
 742                 }
 743
 744                 *lmf = (gpointer)(((guint64)(*lmf)->previous_lmf) & ~7);
 745
 746                 return TRUE;
 747         }
 748
 749         return FALSE;
 750 }
 751
 752 /*
 753  * handle_exception:
 754  *
 755  *   Called by resuming from a signal handler.
 756  */
 757 static void
 758 handle_signal_exception (gpointer obj)
 759 {
 760         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 761         MonoContext ctx;
 762
 763         memcpy (&ctx, &jit_tls->ex_ctx, sizeof (MonoContext));
 764
 765         mono_handle_exception (&ctx, obj);
 766
 767         mono_restore_context (&ctx);
 768 }
 769
 770 void
 771 mono_arch_setup_async_callback (MonoContext *ctx, void (*async_cb)(void *fun), gpointer user_data)
 772 {
 773         guint64 sp = ctx->rsp;
 774
 775         ctx->rdi = (guint64)user_data;
 776
 777         /* Allocate a stack frame below the red zone */
 778         sp -= 128;
 779         /* The stack should be unaligned */
 780         if ((sp % 16) == 0)
 781                 sp -= 8;
 782 #ifdef __linux__
 783         /* Preserve the call chain to prevent crashes in the libgcc unwinder (#15969) */
 784         *(guint64*)sp = ctx->rip;
 785 #endif
 786         ctx->rsp = sp;
 787         ctx->rip = (guint64)async_cb;
 788 }
 789
 790 /**
 791  * mono_arch_handle_exception:
 792  *
 793  * @ctx: saved processor state
 794  * @obj: the exception object
 795  */
 796 gboolean
 797 mono_arch_handle_exception (void *sigctx, gpointer obj)
 798 {
 799 #if defined(MONO_ARCH_USE_SIGACTION)
 800         MonoContext mctx;
 801
 802         /*
 803          * Handling the exception in the signal handler is problematic, since the original
 804          * signal is disabled, and we could run arbitrary code though the debugger. So
 805          * resume into the normal stack and do most work there if possible.
 806          */
 807         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 808
 809         /* Pass the ctx parameter in TLS */
 810         mono_arch_sigctx_to_monoctx (sigctx, &jit_tls->ex_ctx);
 811
 812         mctx = jit_tls->ex_ctx;
 813         mono_arch_setup_async_callback (&mctx, handle_signal_exception, obj);
 814         mono_monoctx_to_sigctx (&mctx, sigctx);
 815
 816         return TRUE;
 817 #else
 818         MonoContext mctx;
 819
 820         mono_arch_sigctx_to_monoctx (sigctx, &mctx);
 821
 822         mono_handle_exception (&mctx, obj);
 823
 824         mono_arch_monoctx_to_sigctx (&mctx, sigctx);
 825
 826         return TRUE;
 827 #endif
 828 }
 829
 830 void
 831 mono_arch_sigctx_to_monoctx (void *sigctx, MonoContext *mctx)
 832 {
 833         mono_sigctx_to_monoctx (sigctx, mctx);
 834 }
 835
 836 void
 837 mono_arch_monoctx_to_sigctx (MonoContext *mctx, void *sigctx)
 838 {
 839         mono_monoctx_to_sigctx (mctx, sigctx);
 840 }
 841
 842 gpointer
 843 mono_arch_ip_from_context (void *sigctx)
 844 {
 845 #if defined(MONO_ARCH_USE_SIGACTION)
 846         ucontext_t *ctx = (ucontext_t*)sigctx;
 847
 848         return (gpointer)UCONTEXT_REG_RIP (ctx);
 849 #else
 850         MonoContext *ctx = sigctx;
 851         return (gpointer)ctx->rip;
 852 #endif
 853 }
 854
 855 static void
 856 restore_soft_guard_pages (void)
 857 {
 858         MonoJitTlsData *jit_tls = mono_native_tls_get_value (mono_jit_tls_id);
 859         if (jit_tls->stack_ovf_guard_base)
 860                 mono_mprotect (jit_tls->stack_ovf_guard_base, jit_tls->stack_ovf_guard_size, MONO_MMAP_NONE);
 861 }
 862
 863 /*
 864  * this function modifies mctx so that when it is restored, it
 865  * won't execcute starting at mctx.eip, but in a function that
 866  * will restore the protection on the soft-guard pages and return back to
 867  * continue at mctx.eip.
 868  */
 869 static void
 870 prepare_for_guard_pages (MonoContext *mctx)
 871 {
 872         gpointer *sp;
 873         sp = (gpointer)(mctx->rsp);
 874         sp -= 1;
 875         /* the return addr */
 876         sp [0] = (gpointer)(mctx->rip);
 877         mctx->rip = (guint64)restore_soft_guard_pages;
 878         mctx->rsp = (guint64)sp;
 879 }
 880
 881 static void
 882 altstack_handle_and_restore (void *sigctx, gpointer obj, gboolean stack_ovf)
 883 {
 884         MonoContext mctx;
 885
 886         mono_arch_sigctx_to_monoctx (sigctx, &mctx);
 887
 888         mono_handle_exception (&mctx, obj);
 889         if (stack_ovf)
 890                 prepare_for_guard_pages (&mctx);
 891         mono_restore_context (&mctx);
 892 }
 893
 894 void
 895 mono_arch_handle_altstack_exception (void *sigctx, gpointer fault_addr, gboolean stack_ovf)
 896 {
 897 #if defined(MONO_ARCH_USE_SIGACTION)
 898         MonoException *exc = NULL;
 899         ucontext_t *ctx = (ucontext_t*)sigctx;
 900         MonoJitInfo *ji = mini_jit_info_table_find (mono_domain_get (), (gpointer)UCONTEXT_REG_RIP (sigctx), NULL);
 901         gpointer *sp;
 902         int frame_size;
 903         ucontext_t *copied_ctx;
 904
 905         if (stack_ovf)
 906                 exc = mono_domain_get ()->stack_overflow_ex;
 907         if (!ji)
 908                 mono_handle_native_sigsegv (SIGSEGV, sigctx);
 909
 910         /* setup a call frame on the real stack so that control is returned there
 911          * and exception handling can continue.
 912          * The frame looks like:
 913          *   ucontext struct
 914          *   ...
 915          *   return ip
 916          * 128 is the size of the red zone
 917          */
 918         frame_size = sizeof (ucontext_t) + sizeof (gpointer) * 4 + 128;
 919 #ifdef __APPLE__
 920         frame_size += sizeof (*ctx->uc_mcontext);
 921 #endif
 922         frame_size += 15;
 923         frame_size &= ~15;
 924         sp = (gpointer)(UCONTEXT_REG_RSP (sigctx) & ~15);
 925         sp = (gpointer)((char*)sp - frame_size);
 926         copied_ctx = (ucontext_t*)(sp + 4);
 927         /* the arguments must be aligned */
 928         sp [-1] = (gpointer)UCONTEXT_REG_RIP (sigctx);
 929         /* may need to adjust pointers in the new struct copy, depending on the OS */
 930         memcpy (copied_ctx, ctx, sizeof (ucontext_t));
 931 #ifdef __APPLE__
 932         {
 933                 guint8 * copied_mcontext = (guint8*)copied_ctx + sizeof (ucontext_t);
 934                 /* uc_mcontext is a pointer, so make a copy which is stored after the ctx */
 935                 memcpy (copied_mcontext, ctx->uc_mcontext, sizeof (*ctx->uc_mcontext));
 936                 copied_ctx->uc_mcontext = (void*)copied_mcontext;
 937         }
 938 #endif
 939         /* at the return form the signal handler execution starts in altstack_handle_and_restore() */
 940         UCONTEXT_REG_RIP (sigctx) = (unsigned long)altstack_handle_and_restore;
 941         UCONTEXT_REG_RSP (sigctx) = (unsigned long)(sp - 1);
 942         UCONTEXT_REG_RDI (sigctx) = (unsigned long)(copied_ctx);
 943         UCONTEXT_REG_RSI (sigctx) = (guint64)exc;
 944         UCONTEXT_REG_RDX (sigctx) = stack_ovf;
 945 #endif
 946 }
 947
 948 guint64
 949 mono_amd64_get_original_ip (void)
 950 {
 951         MonoLMF *lmf = mono_get_lmf ();
 952
 953         g_assert (lmf);
 954
 955         /* Reset the change to previous_lmf */
 956         lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf & ~1);
 957
 958         return lmf->rip;
 959 }
 960
 961 gpointer
 962 mono_arch_get_throw_pending_exception (MonoTrampInfo **info, gboolean aot)
 963 {
 964         guint8 *code, *start;
 965         guint8 *br[1];
 966         gpointer throw_trampoline;
 967         MonoJumpInfo *ji = NULL;
 968         GSList *unwind_ops = NULL;
 969         const guint kMaxCodeSize = NACL_SIZE (128, 256);
 970
 971         start = code = mono_global_codeman_reserve (kMaxCodeSize);
 972
 973         /* We are in the frame of a managed method after a call */
 974         /*
 975          * We would like to throw the pending exception in such a way that it looks to
 976          * be thrown from the managed method.
 977          */
 978
 979         /* Save registers which might contain the return value of the call */
 980         amd64_push_reg (code, AMD64_RAX);
 981         amd64_push_reg (code, AMD64_RDX);
 982
 983         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 984         amd64_movsd_membase_reg (code, AMD64_RSP, 0, AMD64_XMM0);
 985
 986         /* Align stack */
 987         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
 988
 989         /* Obtain the pending exception */
 990         if (aot) {
 991                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_thread_get_and_clear_pending_exception");
 992                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
 993         } else {
 994                 amd64_mov_reg_imm (code, AMD64_R11, mono_thread_get_and_clear_pending_exception);
 995         }
 996         amd64_call_reg (code, AMD64_R11);
 997
 998         /* Check if it is NULL, and branch */
 999         amd64_alu_reg_imm (code, X86_CMP, AMD64_RAX, 0);
1000         br[0] = code; x86_branch8 (code, X86_CC_EQ, 0, FALSE);
1001
1002         /* exc != NULL branch */
1003
1004         /* Save the exc on the stack */
1005         amd64_push_reg (code, AMD64_RAX);
1006         /* Align stack */
1007         amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, 8);
1008
1009         /* Obtain the original ip and clear the flag in previous_lmf */
1010         if (aot) {
1011                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_amd64_get_original_ip");
1012                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
1013         } else {
1014                 amd64_mov_reg_imm (code, AMD64_R11, mono_amd64_get_original_ip);
1015         }
1016         amd64_call_reg (code, AMD64_R11);
1017
1018         /* Load exc */
1019         amd64_mov_reg_membase (code, AMD64_R11, AMD64_RSP, 8, 8);
1020
1021         /* Pop saved stuff from the stack */
1022         amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 6 * 8);
1023
1024         /* Setup arguments for the throw trampoline */
1025         /* Exception */
1026         amd64_mov_reg_reg (code, AMD64_ARG_REG1, AMD64_R11, 8);
1027         /* The trampoline expects the caller ip to be pushed on the stack */
1028         amd64_push_reg (code, AMD64_RAX);
1029
1030         /* Call the throw trampoline */
1031         if (aot) {
1032                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_amd64_throw_exception");
1033                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
1034         } else {
1035                 throw_trampoline = mono_get_throw_exception ();
1036                 amd64_mov_reg_imm (code, AMD64_R11, throw_trampoline);
1037         }
1038         /* We use a jump instead of a call so we can push the original ip on the stack */
1039         amd64_jump_reg (code, AMD64_R11);
1040
1041         /* ex == NULL branch */
1042         mono_amd64_patch (br [0], code);
1043
1044         /* Obtain the original ip and clear the flag in previous_lmf */
1045         if (aot) {
1046                 ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_amd64_get_original_ip");
1047                 amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
1048         } else {
1049                 amd64_mov_reg_imm (code, AMD64_R11, mono_amd64_get_original_ip);
1050         }
1051         amd64_call_reg (code, AMD64_R11);
1052         amd64_mov_reg_reg (code, AMD64_R11, AMD64_RAX, 8);
1053
1054         /* Restore registers */
1055         amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 8);
1056         amd64_movsd_reg_membase (code, AMD64_XMM0, AMD64_RSP, 0);
1057         amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, 8);
1058         amd64_pop_reg (code, AMD64_RDX);
1059         amd64_pop_reg (code, AMD64_RAX);
1060
1061         /* Return to original code */
1062         amd64_jump_reg (code, AMD64_R11);
1063
1064         g_assert ((code - start) < kMaxCodeSize);
1065
1066         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
1067
1068         if (info)
1069                 *info = mono_tramp_info_create ("throw_pending_exception", start, code - start, ji, unwind_ops);
1070
1071         return start;
1072 }
1073
1074 static gpointer throw_pending_exception;
1075
1076 /*
1077  * Called when a thread receives an async exception while executing unmanaged code.
1078  * Instead of checking for this exception in the managed-to-native wrapper, we hijack
1079  * the return address on the stack to point to a helper routine which throws the
1080  * exception.
1081  */
1082 void
1083 mono_arch_notify_pending_exc (void)
1084 {
1085         MonoLMF *lmf = mono_get_lmf ();
1086
1087         if (!lmf)
1088                 /* Not yet started */
1089                 return;
1090
1091         if (lmf->rsp == 0)
1092                 /* Initial LMF */
1093                 return;
1094
1095         if ((guint64)lmf->previous_lmf & 1)
1096                 /* Already hijacked or trampoline LMF entry */
1097                 return;
1098
1099         /* lmf->rsp is set just before making the call which transitions to unmanaged code */
1100         lmf->rip = *(guint64*)(lmf->rsp - 8);
1101         /* Signal that lmf->rip is set */
1102         lmf->previous_lmf = (gpointer)((guint64)lmf->previous_lmf | 1);
1103
1104         *(gpointer*)(lmf->rsp - 8) = throw_pending_exception;
1105 }
1106
1107 GSList*
1108 mono_amd64_get_exception_trampolines (gboolean aot)
1109 {
1110         MonoTrampInfo *info;
1111         GSList *tramps = NULL;
1112
1113         mono_arch_get_throw_pending_exception (&info, aot);
1114         tramps = g_slist_prepend (tramps, info);
1115
1116         /* LLVM needs different throw trampolines */
1117         get_throw_trampoline (&info, FALSE, TRUE, FALSE, FALSE, "llvm_throw_corlib_exception_trampoline", aot);
1118         tramps = g_slist_prepend (tramps, info);
1119
1120         get_throw_trampoline (&info, FALSE, TRUE, TRUE, FALSE, "llvm_throw_corlib_exception_abs_trampoline", aot);
1121         tramps = g_slist_prepend (tramps, info);
1122
1123         get_throw_trampoline (&info, FALSE, TRUE, TRUE, TRUE, "llvm_resume_unwind_trampoline", FALSE);
1124         tramps = g_slist_prepend (tramps, info);
1125
1126         return tramps;
1127 }
1128
1129 void
1130 mono_arch_exceptions_init (void)
1131 {
1132         GSList *tramps, *l;
1133         gpointer tramp;
1134
1135         if (mono_aot_only) {
1136                 throw_pending_exception = mono_aot_get_trampoline ("throw_pending_exception");
1137                 tramp = mono_aot_get_trampoline ("llvm_throw_corlib_exception_trampoline");
1138                 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_trampoline", NULL, TRUE);
1139                 tramp = mono_aot_get_trampoline ("llvm_throw_corlib_exception_abs_trampoline");
1140                 mono_register_jit_icall (tramp, "llvm_throw_corlib_exception_abs_trampoline", NULL, TRUE);
1141                 tramp = mono_aot_get_trampoline ("llvm_resume_unwind_trampoline");
1142                 mono_register_jit_icall (tramp, "llvm_resume_unwind_trampoline", NULL, TRUE);
1143         } else {
1144                 /* Call this to avoid initialization races */
1145                 throw_pending_exception = mono_arch_get_throw_pending_exception (NULL, FALSE);
1146
1147                 tramps = mono_amd64_get_exception_trampolines (FALSE);
1148                 for (l = tramps; l; l = l->next) {
1149                         MonoTrampInfo *info = l->data;
1150
1151                         mono_register_jit_icall (info->code, g_strdup (info->name), NULL, TRUE);
1152                         mono_tramp_info_register (info);
1153                 }
1154                 g_slist_free (tramps);
1155         }
1156 }
1157
1158 #ifdef TARGET_WIN32
1159
1160 /*
1161  * The mono_arch_unwindinfo* methods are used to build and add
1162  * function table info for each emitted method from mono.  On Winx64
1163  * the seh handler will not be called if the mono methods are not
1164  * added to the function table.
1165  *
1166  * We should not need to add non-volatile register info to the
1167  * table since mono stores that info elsewhere. (Except for the register
1168  * used for the fp.)
1169  */
1170
1171 #define MONO_MAX_UNWIND_CODES 22
1172
1173 typedef union _UNWIND_CODE {
1174     struct {
1175         guchar CodeOffset;
1176         guchar UnwindOp : 4;
1177         guchar OpInfo   : 4;
1178     };
1179     gushort FrameOffset;
1180 } UNWIND_CODE, *PUNWIND_CODE;
1181
1182 typedef struct _UNWIND_INFO {
1183         guchar Version       : 3;
1184         guchar Flags         : 5;
1185         guchar SizeOfProlog;
1186         guchar CountOfCodes;
1187         guchar FrameRegister : 4;
1188         guchar FrameOffset   : 4;
1189         /* custom size for mono allowing for mono allowing for*/
1190         /*UWOP_PUSH_NONVOL ebp offset = 21*/
1191         /*UWOP_ALLOC_LARGE : requires 2 or 3 offset = 20*/
1192         /*UWOP_SET_FPREG : requires 2 offset = 17*/
1193         /*UWOP_PUSH_NONVOL offset = 15-0*/
1194         UNWIND_CODE UnwindCode[MONO_MAX_UNWIND_CODES];
1195
1196 /*      UNWIND_CODE MoreUnwindCode[((CountOfCodes + 1) & ~1) - 1];
1197  *      union {
1198  *          OPTIONAL ULONG ExceptionHandler;
1199  *          OPTIONAL ULONG FunctionEntry;
1200  *      };
1201  *      OPTIONAL ULONG ExceptionData[]; */
1202 } UNWIND_INFO, *PUNWIND_INFO;
1203
1204 typedef struct
1205 {
1206         RUNTIME_FUNCTION runtimeFunction;
1207         UNWIND_INFO unwindInfo;
1208 } MonoUnwindInfo, *PMonoUnwindInfo;
1209
1210 static void
1211 mono_arch_unwindinfo_create (gpointer* monoui)
1212 {
1213         PMonoUnwindInfo newunwindinfo;
1214         *monoui = newunwindinfo = g_new0 (MonoUnwindInfo, 1);
1215         newunwindinfo->unwindInfo.Version = 1;
1216 }
1217
1218 void
1219 mono_arch_unwindinfo_add_push_nonvol (gpointer* monoui, gpointer codebegin, gpointer nextip, guchar reg )
1220 {
1221         PMonoUnwindInfo unwindinfo;
1222         PUNWIND_CODE unwindcode;
1223         guchar codeindex;
1224         if (!*monoui)
1225                 mono_arch_unwindinfo_create (monoui);
1226
1227         unwindinfo = (MonoUnwindInfo*)*monoui;
1228
1229         if (unwindinfo->unwindInfo.CountOfCodes >= MONO_MAX_UNWIND_CODES)
1230                 g_error ("Larger allocation needed for the unwind information.");
1231
1232         codeindex = MONO_MAX_UNWIND_CODES - (++unwindinfo->unwindInfo.CountOfCodes);
1233         unwindcode = &unwindinfo->unwindInfo.UnwindCode[codeindex];
1234         unwindcode->UnwindOp = 0; /*UWOP_PUSH_NONVOL*/
1235         unwindcode->CodeOffset = (((guchar*)nextip)-((guchar*)codebegin));
1236         unwindcode->OpInfo = reg;
1237
1238         if (unwindinfo->unwindInfo.SizeOfProlog >= unwindcode->CodeOffset)
1239                 g_error ("Adding unwind info in wrong order.");
1240
1241         unwindinfo->unwindInfo.SizeOfProlog = unwindcode->CodeOffset;
1242 }
1243
1244 void
1245 mono_arch_unwindinfo_add_set_fpreg (gpointer* monoui, gpointer codebegin, gpointer nextip, guchar reg )
1246 {
1247         PMonoUnwindInfo unwindinfo;
1248         PUNWIND_CODE unwindcode;
1249         guchar codeindex;
1250         if (!*monoui)
1251                 mono_arch_unwindinfo_create (monoui);
1252
1253         unwindinfo = (MonoUnwindInfo*)*monoui;
1254
1255         if (unwindinfo->unwindInfo.CountOfCodes + 1 >= MONO_MAX_UNWIND_CODES)
1256                 g_error ("Larger allocation needed for the unwind information.");
1257
1258         codeindex = MONO_MAX_UNWIND_CODES - (unwindinfo->unwindInfo.CountOfCodes += 2);
1259         unwindcode = &unwindinfo->unwindInfo.UnwindCode[codeindex];
1260         unwindcode->FrameOffset = 0; /*Assuming no frame pointer offset for mono*/
1261         unwindcode++;
1262         unwindcode->UnwindOp = 3; /*UWOP_SET_FPREG*/
1263         unwindcode->CodeOffset = (((guchar*)nextip)-((guchar*)codebegin));
1264         unwindcode->OpInfo = reg;
1265
1266         unwindinfo->unwindInfo.FrameRegister = reg;
1267
1268         if (unwindinfo->unwindInfo.SizeOfProlog >= unwindcode->CodeOffset)
1269                 g_error ("Adding unwind info in wrong order.");
1270
1271         unwindinfo->unwindInfo.SizeOfProlog = unwindcode->CodeOffset;
1272 }
1273
1274 void
1275 mono_arch_unwindinfo_add_alloc_stack (gpointer* monoui, gpointer codebegin, gpointer nextip, guint size )
1276 {
1277         PMonoUnwindInfo unwindinfo;
1278         PUNWIND_CODE unwindcode;
1279         guchar codeindex;
1280         guchar codesneeded;
1281         if (!*monoui)
1282                 mono_arch_unwindinfo_create (monoui);
1283
1284         unwindinfo = (MonoUnwindInfo*)*monoui;
1285
1286         if (size < 0x8)
1287                 g_error ("Stack allocation must be equal to or greater than 0x8.");
1288
1289         if (size <= 0x80)
1290                 codesneeded = 1;
1291         else if (size <= 0x7FFF8)
1292                 codesneeded = 2;
1293         else
1294                 codesneeded = 3;
1295
1296         if (unwindinfo->unwindInfo.CountOfCodes + codesneeded > MONO_MAX_UNWIND_CODES)
1297                 g_error ("Larger allocation needed for the unwind information.");
1298
1299         codeindex = MONO_MAX_UNWIND_CODES - (unwindinfo->unwindInfo.CountOfCodes += codesneeded);
1300         unwindcode = &unwindinfo->unwindInfo.UnwindCode[codeindex];
1301
1302         if (codesneeded == 1) {
1303                 /*The size of the allocation is
1304                   (the number in the OpInfo member) times 8 plus 8*/
1305                 unwindcode->OpInfo = (size - 8)/8;
1306                 unwindcode->UnwindOp = 2; /*UWOP_ALLOC_SMALL*/
1307         }
1308         else {
1309                 if (codesneeded == 3) {
1310                         /*the unscaled size of the allocation is recorded
1311                           in the next two slots in little-endian format*/
1312                         *((unsigned int*)(&unwindcode->FrameOffset)) = size;
1313                         unwindcode += 2;
1314                         unwindcode->OpInfo = 1;
1315                 }
1316                 else {
1317                         /*the size of the allocation divided by 8
1318                           is recorded in the next slot*/
1319                         unwindcode->FrameOffset = size/8;
1320                         unwindcode++;
1321                         unwindcode->OpInfo = 0;
1322
1323                 }
1324                 unwindcode->UnwindOp = 1; /*UWOP_ALLOC_LARGE*/
1325         }
1326
1327         unwindcode->CodeOffset = (((guchar*)nextip)-((guchar*)codebegin));
1328
1329         if (unwindinfo->unwindInfo.SizeOfProlog >= unwindcode->CodeOffset)
1330                 g_error ("Adding unwind info in wrong order.");
1331
1332         unwindinfo->unwindInfo.SizeOfProlog = unwindcode->CodeOffset;
1333 }
1334
1335 guint
1336 mono_arch_unwindinfo_get_size (gpointer monoui)
1337 {
1338         PMonoUnwindInfo unwindinfo;
1339         if (!monoui)
1340                 return 0;
1341
1342         unwindinfo = (MonoUnwindInfo*)monoui;
1343         return (8 + sizeof (MonoUnwindInfo)) -
1344                 (sizeof (UNWIND_CODE) * (MONO_MAX_UNWIND_CODES - unwindinfo->unwindInfo.CountOfCodes));
1345 }
1346
1347 PRUNTIME_FUNCTION
1348 MONO_GET_RUNTIME_FUNCTION_CALLBACK ( DWORD64 ControlPc, IN PVOID Context )
1349 {
1350         MonoJitInfo *ji;
1351         guint64 pos;
1352         PMonoUnwindInfo targetinfo;
1353         MonoDomain *domain = mono_domain_get ();
1354
1355         ji = mini_jit_info_table_find (domain, (char*)ControlPc, NULL);
1356         if (!ji)
1357                 return 0;
1358
1359         pos = (guint64)(((char*)ji->code_start) + ji->code_size);
1360
1361         targetinfo = (PMonoUnwindInfo)ALIGN_TO (pos, 8);
1362
1363         targetinfo->runtimeFunction.UnwindData = ((DWORD64)&targetinfo->unwindInfo) - ((DWORD64)Context);
1364
1365         return &targetinfo->runtimeFunction;
1366 }
1367
1368 void
1369 mono_arch_unwindinfo_install_unwind_info (gpointer* monoui, gpointer code, guint code_size)
1370 {
1371         PMonoUnwindInfo unwindinfo, targetinfo;
1372         guchar codecount;
1373         guint64 targetlocation;
1374         if (!*monoui)
1375                 return;
1376
1377         unwindinfo = (MonoUnwindInfo*)*monoui;
1378         targetlocation = (guint64)&(((guchar*)code)[code_size]);
1379         targetinfo = (PMonoUnwindInfo) ALIGN_TO(targetlocation, 8);
1380
1381         unwindinfo->runtimeFunction.EndAddress = code_size;
1382         unwindinfo->runtimeFunction.UnwindData = ((guchar*)&targetinfo->unwindInfo) - ((guchar*)code);
1383
1384         memcpy (targetinfo, unwindinfo, sizeof (MonoUnwindInfo) - (sizeof (UNWIND_CODE) * MONO_MAX_UNWIND_CODES));
1385
1386         codecount = unwindinfo->unwindInfo.CountOfCodes;
1387         if (codecount) {
1388                 memcpy (&targetinfo->unwindInfo.UnwindCode[0], &unwindinfo->unwindInfo.UnwindCode[MONO_MAX_UNWIND_CODES-codecount],
1389                         sizeof (UNWIND_CODE) * unwindinfo->unwindInfo.CountOfCodes);
1390         }
1391
1392         g_free (unwindinfo);
1393         *monoui = 0;
1394
1395         RtlInstallFunctionTableCallback (((DWORD64)code) | 0x3, (DWORD64)code, code_size, MONO_GET_RUNTIME_FUNCTION_CALLBACK, code, NULL);
1396 }
1397
1398 #endif
1399
1400 #if MONO_SUPPORT_TASKLETS
1401 MonoContinuationRestore
1402 mono_tasklets_arch_restore (void)
1403 {
1404         static guint8* saved = NULL;
1405         guint8 *code, *start;
1406         int cont_reg = AMD64_R9; /* register usable on both call conventions */
1407         const guint kMaxCodeSize = NACL_SIZE (64, 128);
1408
1409
1410         if (saved)
1411                 return (MonoContinuationRestore)saved;
1412         code = start = mono_global_codeman_reserve (kMaxCodeSize);
1413         /* the signature is: restore (MonoContinuation *cont, int state, MonoLMF **lmf_addr) */
1414         /* cont is in AMD64_ARG_REG1 ($rcx or $rdi)
1415          * state is in AMD64_ARG_REG2 ($rdx or $rsi)
1416          * lmf_addr is in AMD64_ARG_REG3 ($r8 or $rdx)
1417          * We move cont to cont_reg since we need both rcx and rdi for the copy
1418          * state is moved to $rax so it's setup as the return value and we can overwrite $rsi
1419          */
1420         amd64_mov_reg_reg (code, cont_reg, MONO_AMD64_ARG_REG1, 8);
1421         amd64_mov_reg_reg (code, AMD64_RAX, MONO_AMD64_ARG_REG2, 8);
1422         /* setup the copy of the stack */
1423         amd64_mov_reg_membase (code, AMD64_RCX, cont_reg, G_STRUCT_OFFSET (MonoContinuation, stack_used_size), sizeof (int));
1424         amd64_shift_reg_imm (code, X86_SHR, AMD64_RCX, 3);
1425         x86_cld (code);
1426         amd64_mov_reg_membase (code, AMD64_RSI, cont_reg, G_STRUCT_OFFSET (MonoContinuation, saved_stack), sizeof (gpointer));
1427         amd64_mov_reg_membase (code, AMD64_RDI, cont_reg, G_STRUCT_OFFSET (MonoContinuation, return_sp), sizeof (gpointer));
1428         amd64_prefix (code, X86_REP_PREFIX);
1429         amd64_movsl (code);
1430
1431         /* now restore the registers from the LMF */
1432         amd64_mov_reg_membase (code, AMD64_RCX, cont_reg, G_STRUCT_OFFSET (MonoContinuation, lmf), 8);
1433         amd64_mov_reg_membase (code, AMD64_RBX, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, rbx), 8);
1434         amd64_mov_reg_membase (code, AMD64_RBP, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, rbp), 8);
1435         amd64_mov_reg_membase (code, AMD64_R12, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, r12), 8);
1436         amd64_mov_reg_membase (code, AMD64_R13, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, r13), 8);
1437         amd64_mov_reg_membase (code, AMD64_R14, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, r14), 8);
1438 #if !defined(__native_client_codegen__)
1439         amd64_mov_reg_membase (code, AMD64_R15, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, r15), 8);
1440 #endif
1441 #ifdef TARGET_WIN32
1442         amd64_mov_reg_membase (code, AMD64_RDI, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, rdi), 8);
1443         amd64_mov_reg_membase (code, AMD64_RSI, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, rsi), 8);
1444 #endif
1445         amd64_mov_reg_membase (code, AMD64_RSP, AMD64_RCX, G_STRUCT_OFFSET (MonoLMF, rsp), 8);
1446
1447         /* restore the lmf chain */
1448         /*x86_mov_reg_membase (code, X86_ECX, X86_ESP, 12, 4);
1449         x86_mov_membase_reg (code, X86_ECX, 0, X86_EDX, 4);*/
1450
1451         /* state is already in rax */
1452         amd64_jump_membase (code, cont_reg, G_STRUCT_OFFSET (MonoContinuation, return_ip));
1453         g_assert ((code - start) <= kMaxCodeSize);
1454
1455         nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
1456
1457         saved = start;
1458         return (MonoContinuationRestore)saved;
1459 }
1460 #endif
1461
1462 /*
1463  * mono_arch_setup_resume_sighandler_ctx:
1464  *
1465  *   Setup CTX so execution continues at FUNC.
1466  */
1467 void
1468 mono_arch_setup_resume_sighandler_ctx (MonoContext *ctx, gpointer func)
1469 {
1470         /*
1471          * When resuming from a signal handler, the stack should be misaligned, just like right after
1472          * a call.
1473          */
1474         if ((((guint64)MONO_CONTEXT_GET_SP (ctx)) % 16) == 0)
1475                 MONO_CONTEXT_SET_SP (ctx, (guint64)MONO_CONTEXT_GET_SP (ctx) - 8);
1476         MONO_CONTEXT_SET_IP (ctx, func);
1477 }