mono/arch/x86/tramp.c

   1 /*
   2  * Create trampolines to invoke arbitrary functions.
   3  *
   4  * Copyright (C) Ximian Inc.
   5  *
   6  * Authors:
   7  *   Paolo Molaro (lupus@ximian.com)
   8  *   Dietmar Maurer (dietmar@ximian.com)
   9  *
  10  */
  11
  12 #include "config.h"
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include "x86-codegen.h"
  16 #include "mono/metadata/class.h"
  17 #include "mono/metadata/tabledefs.h"
  18 #include "mono/interpreter/interp.h"
  19 #include "mono/metadata/appdomain.h"
  20 #include "mono/metadata/marshal.h"
  21
  22 /*
  23  * The resulting function takes the form:
  24  * void func (void (*callme)(), void *retval, void *this_obj, stackval *arguments);
  25  */
  26 #define FUNC_ADDR_POS   8
  27 #define RETVAL_POS      12
  28 #define THIS_POS        16
  29 #define ARGP_POS        20
  30 #define LOC_POS -4
  31
  32 #define ARG_SIZE        sizeof (stackval)
  33
  34 MonoPIFunc
  35 mono_arch_create_trampoline (MonoMethodSignature *sig, gboolean string_ctor)
  36 {
  37         unsigned char *p, *code_buffer;
  38         guint32 stack_size = 0, code_size = 50;
  39         guint32 arg_pos, simpletype;
  40         int i, stringp;
  41         static GHashTable *cache = NULL;
  42         MonoPIFunc res;
  43
  44         if (!cache)
  45                 cache = g_hash_table_new ((GHashFunc)mono_signature_hash,
  46                                           (GCompareFunc)mono_metadata_signature_equal);
  47
  48         if ((res = (MonoPIFunc)g_hash_table_lookup (cache, sig)))
  49                 return res;
  50
  51         if (sig->hasthis) {
  52                 stack_size += sizeof (gpointer);
  53                 code_size += 10;
  54         }
  55
  56         if (sig->ret->type == MONO_TYPE_VALUETYPE && !sig->ret->byref && !sig->ret->data.klass->enumtype) {
  57                 stack_size += sizeof (gpointer);
  58                 code_size += 5;
  59         }
  60
  61         for (i = 0; i < sig->param_count; ++i) {
  62                 if (sig->params [i]->byref) {
  63                         stack_size += sizeof (gpointer);
  64                         code_size += 20;
  65                         continue;
  66                 }
  67                 simpletype = sig->params [i]->type;
  68 enum_calc_size:
  69                 switch (simpletype) {
  70                 case MONO_TYPE_BOOLEAN:
  71                 case MONO_TYPE_CHAR:
  72                 case MONO_TYPE_I1:
  73                 case MONO_TYPE_U1:
  74                 case MONO_TYPE_I2:
  75                 case MONO_TYPE_U2:
  76                 case MONO_TYPE_I4:
  77                 case MONO_TYPE_U4:
  78                 case MONO_TYPE_I:
  79                 case MONO_TYPE_U:
  80                 case MONO_TYPE_PTR:
  81                 case MONO_TYPE_SZARRAY:
  82                 case MONO_TYPE_CLASS:
  83                 case MONO_TYPE_OBJECT:
  84                 case MONO_TYPE_STRING:
  85                         stack_size += 4;
  86                         code_size += i < 10 ? 5 : 8;
  87                         break;
  88                 case MONO_TYPE_VALUETYPE: {
  89                         int size;
  90                         if (sig->params [i]->data.klass->enumtype) {
  91                                 simpletype = sig->params [i]->data.klass->enum_basetype->type;
  92                                 goto enum_calc_size;
  93                         }
  94                         if ((size = mono_class_native_size (sig->params [i]->data.klass, NULL)) != 4) {
  95                                 stack_size += size + 3;
  96                                 stack_size &= ~3;
  97                                 code_size += 32;
  98                         } else {
  99                                 stack_size += 4;
 100                                 code_size += i < 10 ? 5 : 8;
 101                         }
 102                         break;
 103                 }
 104                 case MONO_TYPE_I8:
 105                         stack_size += 8;
 106                         code_size += i < 10 ? 5 : 8;
 107                         break;
 108                 case MONO_TYPE_R4:
 109                         stack_size += 4;
 110                         code_size += i < 10 ? 10 : 13;
 111                         break;
 112                 case MONO_TYPE_R8:
 113                         stack_size += 8;
 114                         code_size += i < 10 ? 7 : 10;
 115                         break;
 116                 default:
 117                         g_error ("Can't trampoline 0x%x", sig->params [i]->type);
 118                 }
 119         }
 120         /*
 121          * FIXME: take into account large return values.
 122          */
 123
 124         code_buffer = p = alloca (code_size);
 125
 126         /*
 127          * Standard function prolog.
 128          */
 129         x86_push_reg (p, X86_EBP);
 130         x86_mov_reg_reg (p, X86_EBP, X86_ESP, 4);
 131         /*
 132          * and align to 16 byte boundary...
 133          */
 134         stack_size += 15;
 135         stack_size &= ~15;
 136
 137         if (stack_size)
 138                 x86_alu_reg_imm (p, X86_SUB, X86_ESP, stack_size);
 139
 140         /*
 141          * EDX has the pointer to the args.
 142          */
 143         x86_mov_reg_membase (p, X86_EDX, X86_EBP, ARGP_POS, 4);
 144
 145         /*
 146          * Push arguments in reverse order.
 147          */
 148         stringp = 0;
 149         for (i = sig->param_count; i; --i) {
 150                 arg_pos = ARG_SIZE * (i - 1);
 151                 if (sig->params [i - 1]->byref) {
 152                         x86_push_membase (p, X86_EDX, arg_pos);
 153                         continue;
 154                 }
 155                 simpletype = sig->params [i - 1]->type;
 156 enum_marshal:
 157                 switch (simpletype) {
 158                 case MONO_TYPE_BOOLEAN:
 159                 case MONO_TYPE_I1:
 160                 case MONO_TYPE_U1:
 161                 case MONO_TYPE_I2:
 162                 case MONO_TYPE_U2:
 163                 case MONO_TYPE_CHAR:
 164                 case MONO_TYPE_I4:
 165                 case MONO_TYPE_U4:
 166                 case MONO_TYPE_I:
 167                 case MONO_TYPE_U:
 168                 case MONO_TYPE_PTR:
 169                 case MONO_TYPE_OBJECT:
 170                 case MONO_TYPE_STRING:
 171                         x86_push_membase (p, X86_EDX, arg_pos);
 172                         break;
 173                 case MONO_TYPE_R4:
 174                         x86_alu_reg_imm (p, X86_SUB, X86_ESP, 4);
 175                         x86_fld_membase (p, X86_EDX, arg_pos, TRUE);
 176                         x86_fst_membase (p, X86_ESP, 0, FALSE, TRUE);
 177                         break;
 178                 case MONO_TYPE_CLASS:
 179                         x86_push_membase (p, X86_EDX, arg_pos);
 180                         break;
 181                 case MONO_TYPE_SZARRAY:
 182                         x86_push_membase (p, X86_EDX, arg_pos);
 183                         break;
 184                 case MONO_TYPE_VALUETYPE:
 185                         if (!sig->params [i - 1]->data.klass->enumtype) {
 186                                 int size = mono_class_native_size (sig->params [i - 1]->data.klass, NULL);
 187                                 if (size == 4) {
 188                                         /* it's a structure that fits in 4 bytes, need to push the value pointed to */
 189                                         x86_mov_reg_membase (p, X86_EAX, X86_EDX, arg_pos, 4);
 190                                         x86_push_regp (p, X86_EAX);
 191                                 } else {
 192                                         int ss = size;
 193                                         ss += 3;
 194                                         ss &= ~3;
 195
 196                                         x86_alu_reg_imm (p, X86_SUB, X86_ESP, ss);
 197                                         x86_push_imm (p, size);
 198                                         x86_push_membase (p, X86_EDX, arg_pos);
 199                                         x86_lea_membase (p, X86_EAX, X86_ESP, 2*4);
 200                                         x86_push_reg (p, X86_EAX);
 201                                         x86_mov_reg_imm (p, X86_EAX, memcpy);
 202                                         x86_call_reg (p, X86_EAX);
 203                                         x86_alu_reg_imm (p, X86_ADD, X86_ESP, 12);
 204                                         /* memcpy might clobber EDX so restore it */
 205                                         x86_mov_reg_membase (p, X86_EDX, X86_EBP, ARGP_POS, 4);
 206                                 }
 207                         } else {
 208                                 /* it's an enum value */
 209                                 simpletype = sig->params [i - 1]->data.klass->enum_basetype->type;
 210                                 goto enum_marshal;
 211                         }
 212                         break;
 213                 case MONO_TYPE_I8:
 214                 case MONO_TYPE_U8:
 215                 case MONO_TYPE_R8:
 216                         x86_push_membase (p, X86_EDX, arg_pos + 4);
 217                         x86_push_membase (p, X86_EDX, arg_pos);
 218                         break;
 219                 default:
 220                         g_error ("Can't trampoline 0x%x", sig->params [i - 1]->type);
 221                 }
 222         }
 223
 224         if (sig->hasthis) {
 225                 if (sig->call_convention != MONO_CALL_THISCALL) {
 226                         x86_mov_reg_membase (p, X86_EDX, X86_EBP, THIS_POS, 4);
 227                         x86_push_reg (p, X86_EDX);
 228                 } else {
 229                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, THIS_POS, 4);
 230                 }
 231         }
 232
 233         if (sig->ret->type == MONO_TYPE_VALUETYPE && !sig->ret->byref) {
 234                 MonoClass *klass = sig->ret->data.klass;
 235                 if (!klass->enumtype) {
 236                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 237                         x86_push_membase (p, X86_ECX, 0);
 238                 }
 239         }
 240
 241         /*
 242          * Insert call to function
 243          */
 244         x86_mov_reg_membase (p, X86_EDX, X86_EBP, FUNC_ADDR_POS, 4);
 245         x86_call_reg (p, X86_EDX);
 246
 247         /*
 248          * Handle retval.
 249          * Small integer and pointer values are in EAX.
 250          * Long integers are in EAX:EDX.
 251          * FP values are on the FP stack.
 252          */
 253
 254         if (sig->ret->byref || string_ctor) {
 255                 x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 256                 x86_mov_regp_reg (p, X86_ECX, X86_EAX, 4);
 257         } else {
 258                 simpletype = sig->ret->type;
 259         enum_retvalue:
 260                 switch (simpletype) {
 261                 case MONO_TYPE_BOOLEAN:
 262                 case MONO_TYPE_I1:
 263                 case MONO_TYPE_U1:
 264                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 265                         x86_mov_regp_reg (p, X86_ECX, X86_EAX, 1);
 266                         break;
 267                 case MONO_TYPE_CHAR:
 268                 case MONO_TYPE_I2:
 269                 case MONO_TYPE_U2:
 270                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 271                         x86_mov_regp_reg (p, X86_ECX, X86_EAX, 2);
 272                         break;
 273                 case MONO_TYPE_I4:
 274                 case MONO_TYPE_U4:
 275                 case MONO_TYPE_I:
 276                 case MONO_TYPE_U:
 277                 case MONO_TYPE_CLASS:
 278                 case MONO_TYPE_OBJECT:
 279                 case MONO_TYPE_SZARRAY:
 280                 case MONO_TYPE_ARRAY:
 281                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 282                         x86_mov_regp_reg (p, X86_ECX, X86_EAX, 4);
 283                         break;
 284                 case MONO_TYPE_STRING:
 285                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 286                         x86_mov_regp_reg (p, X86_ECX, X86_EAX, 4);
 287                         break;
 288                 case MONO_TYPE_R4:
 289                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 290                         x86_fst_membase (p, X86_ECX, 0, FALSE, TRUE);
 291                         break;
 292                 case MONO_TYPE_R8:
 293                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 294                         x86_fst_membase (p, X86_ECX, 0, TRUE, TRUE);
 295                         break;
 296                 case MONO_TYPE_I8:
 297                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, RETVAL_POS, 4);
 298                         x86_mov_regp_reg (p, X86_ECX, X86_EAX, 4);
 299                         x86_mov_membase_reg (p, X86_ECX, 4, X86_EDX, 4);
 300                         break;
 301                 case MONO_TYPE_VALUETYPE:
 302                         if (sig->ret->data.klass->enumtype) {
 303                                 simpletype = sig->ret->data.klass->enum_basetype->type;
 304                                 goto enum_retvalue;
 305                         }
 306                 case MONO_TYPE_VOID:
 307                         break;
 308                 default:
 309                         g_error ("Can't handle as return value 0x%x", sig->ret->type);
 310                 }
 311         }
 312
 313         /*
 314          * Standard epilog.
 315          */
 316         x86_leave (p);
 317         x86_ret (p);
 318
 319         g_assert (p - code_buffer < code_size);
 320         res = (MonoPIFunc)g_memdup (code_buffer, p - code_buffer);
 321
 322         g_hash_table_insert (cache, sig, res);
 323
 324         return res;
 325 }
 326
 327 #define MINV_POS  (- sizeof (MonoInvocation))
 328 #define STACK_POS (MINV_POS - sizeof (stackval) * sig->param_count)
 329 #define TYPE_OFFSET (G_STRUCT_OFFSET (stackval, type))
 330
 331 /*
 332  * Returns a pointer to a native function that can be used to
 333  * call the specified method.
 334  * The function created will receive the arguments according
 335  * to the call convention specified in the method.
 336  * This function works by creating a MonoInvocation structure,
 337  * filling the fields in and calling ves_exec_method on it.
 338  * Still need to figure out how to handle the exception stuff
 339  * across the managed/unmanaged boundary.
 340  */
 341 void *
 342 mono_arch_create_method_pointer (MonoMethod *method)
 343 {
 344         MonoMethodSignature *sig;
 345         MonoJitInfo *ji;
 346         unsigned char *p, *code_buffer;
 347         gint32 local_size;
 348         gint32 stackval_pos, arg_pos = 8;
 349         int i, size, align, cpos;
 350         int *vtbuf;
 351
 352         sig = method->signature;
 353
 354         code_buffer = p = alloca (512); /* FIXME: check for overflows... */
 355         vtbuf = alloca (sizeof(int)*sig->param_count);
 356
 357         local_size = sizeof (MonoInvocation) + sizeof (stackval) * (sig->param_count + 1);
 358
 359         local_size += 7;
 360         local_size &= ~7;
 361
 362         stackval_pos = -local_size;
 363
 364         cpos = 0;
 365         for (i = 0; i < sig->param_count; i++) {
 366                 MonoType *type = sig->params [i];
 367                 vtbuf [i] = -1;
 368                 if (type->type == MONO_TYPE_VALUETYPE) {
 369                         MonoClass *klass = type->data.klass;
 370                         if (klass->enumtype)
 371                                 continue;
 372                         size = mono_class_native_size (klass, &align);
 373                         cpos += align - 1;
 374                         cpos &= ~(align - 1);
 375                         vtbuf [i] = cpos;
 376                         cpos += size;
 377                 }
 378         }
 379
 380         cpos += 7;
 381         cpos &= ~7;
 382
 383         local_size += cpos;
 384
 385         /*
 386          * Standard function prolog.
 387          */
 388         x86_push_reg (p, X86_EBP);
 389         x86_mov_reg_reg (p, X86_EBP, X86_ESP, 4);
 390         x86_alu_reg_imm (p, X86_SUB, X86_ESP, local_size);
 391
 392         /*
 393          * Initialize MonoInvocation fields, first the ones known now.
 394          */
 395         x86_mov_reg_imm (p, X86_EAX, 0);
 396         x86_mov_membase_reg (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, ex)), X86_EAX, 4);
 397         x86_mov_membase_reg (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, ex_handler)), X86_EAX, 4);
 398         x86_mov_membase_reg (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, parent)), X86_EAX, 4);
 399         /*
 400          * Set the method pointer.
 401          */
 402         x86_mov_membase_imm (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, method)), (int)method, 4);
 403
 404         if (sig->ret->type == MONO_TYPE_VALUETYPE && !sig->ret->byref && !sig->ret->data.klass->enumtype)
 405                 arg_pos += 4;
 406
 407         /*
 408          * Handle this.
 409          */
 410         if (sig->hasthis) {
 411                 if (sig->call_convention != MONO_CALL_THISCALL) {
 412                         /*
 413                          * Grab it from the stack, otherwise it's already in ECX.
 414                          */
 415                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, arg_pos, 4);
 416                         arg_pos += 4;
 417                 }
 418                 x86_mov_membase_reg (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, obj)), X86_ECX, 4);
 419         }
 420         /*
 421          * Handle the arguments. stackval_pos is the posset of the stackval array from EBP.
 422          * arg_pos is the offset from EBP to the incoming arg on the stack.
 423          * We just call stackval_from_data to handle all the (nasty) issues....
 424          */
 425         x86_lea_membase (p, X86_EAX, X86_EBP, stackval_pos);
 426         x86_mov_membase_reg (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, stack_args)), X86_EAX, 4);
 427         for (i = 0; i < sig->param_count; ++i) {
 428                 if (vtbuf [i] >= 0) {
 429                         x86_lea_membase (p, X86_EAX, X86_EBP, - local_size + vtbuf [i]);
 430                         x86_mov_membase_reg (p, X86_EBP, stackval_pos, X86_EAX, 4);
 431                 }
 432                 x86_mov_reg_imm (p, X86_ECX, stackval_from_data);
 433                 x86_lea_membase (p, X86_EDX, X86_EBP, arg_pos);
 434                 x86_lea_membase (p, X86_EAX, X86_EBP, stackval_pos);
 435                 x86_push_imm (p, sig->pinvoke);
 436                 x86_push_reg (p, X86_EDX);
 437                 x86_push_reg (p, X86_EAX);
 438                 x86_push_imm (p, sig->params [i]);
 439                 x86_call_reg (p, X86_ECX);
 440                 x86_alu_reg_imm (p, X86_SUB, X86_ESP, 16);
 441                 stackval_pos += sizeof (stackval);
 442                 /* fixme: alignment */
 443                 if (sig->pinvoke)
 444                         arg_pos += mono_type_native_stack_size (sig->params [i], &align);
 445                 else
 446                         arg_pos += mono_type_stack_size (sig->params [i], &align);
 447         }
 448
 449         /*
 450          * Handle the return value storage area.
 451          */
 452         x86_lea_membase (p, X86_EAX, X86_EBP, stackval_pos);
 453         x86_mov_membase_reg (p, X86_EBP, (MINV_POS + G_STRUCT_OFFSET (MonoInvocation, retval)), X86_EAX, 4);
 454         if (sig->ret->type == MONO_TYPE_VALUETYPE && !sig->ret->byref) {
 455                 MonoClass *klass  = sig->ret->data.klass;
 456                 if (!klass->enumtype) {
 457                         x86_mov_reg_membase (p, X86_ECX, X86_EBP, 8, 4);
 458                         x86_mov_membase_reg (p, X86_EBP, stackval_pos, X86_ECX, 4);
 459                 }
 460         }
 461
 462         /*
 463          * Call the method.
 464          */
 465         x86_lea_membase (p, X86_EAX, X86_EBP, MINV_POS);
 466         x86_push_reg (p, X86_EAX);
 467         x86_mov_reg_imm (p, X86_EDX, ves_exec_method);
 468         x86_call_reg (p, X86_EDX);
 469
 470         /*
 471          * Move the return value to the proper place.
 472          */
 473         x86_lea_membase (p, X86_EAX, X86_EBP, stackval_pos);
 474         if (sig->ret->byref) {
 475                 x86_mov_reg_membase (p, X86_EAX, X86_EAX, 0, 4);
 476         } else {
 477                 int simpletype = sig->ret->type;
 478         enum_retvalue:
 479                 switch (sig->ret->type) {
 480                 case MONO_TYPE_VOID:
 481                         break;
 482                 case MONO_TYPE_BOOLEAN:
 483                 case MONO_TYPE_I1:
 484                 case MONO_TYPE_U1:
 485                         x86_mov_reg_membase (p, X86_EAX, X86_EAX, 0, 1);
 486                         break;
 487                 case MONO_TYPE_CHAR:
 488                 case MONO_TYPE_I2:
 489                 case MONO_TYPE_U2:
 490                         x86_mov_reg_membase (p, X86_EAX, X86_EAX, 0, 2);
 491                         break;
 492                 case MONO_TYPE_I4:
 493                 case MONO_TYPE_U4:
 494                 case MONO_TYPE_I:
 495                 case MONO_TYPE_U:
 496                 case MONO_TYPE_OBJECT:
 497                 case MONO_TYPE_STRING:
 498                 case MONO_TYPE_CLASS:
 499                         x86_mov_reg_membase (p, X86_EAX, X86_EAX, 0, 4);
 500                         break;
 501                 case MONO_TYPE_I8:
 502                         x86_mov_reg_membase (p, X86_EDX, X86_EAX, 4, 4);
 503                         x86_mov_reg_membase (p, X86_EAX, X86_EAX, 0, 4);
 504                         break;
 505                 case MONO_TYPE_R8:
 506                         x86_fld_membase (p, X86_EAX, 0, TRUE);
 507                         break;
 508                 case MONO_TYPE_VALUETYPE:
 509                         if (sig->ret->data.klass->enumtype) {
 510                                 simpletype = sig->ret->data.klass->enum_basetype->type;
 511                                 goto enum_retvalue;
 512                         }
 513
 514                         x86_push_imm (p, sig->pinvoke);
 515                         x86_push_membase (p, X86_EBP, stackval_pos);
 516                         x86_push_reg (p, X86_EAX);
 517                         x86_push_imm (p, sig->ret);
 518                         x86_mov_reg_imm (p, X86_ECX, stackval_to_data);
 519                         x86_call_reg (p, X86_ECX);
 520                         x86_alu_reg_imm (p, X86_SUB, X86_ESP, 16);
 521
 522                         break;
 523                 default:
 524                         g_error ("Type 0x%x not handled yet in thunk creation", sig->ret->type);
 525                         break;
 526                 }
 527         }
 528
 529         /*
 530          * Standard epilog.
 531          */
 532         x86_leave (p);
 533         x86_ret (p);
 534
 535         g_assert (p - code_buffer < 512);
 536
 537         ji = g_new0 (MonoJitInfo, 1);
 538         ji->method = method;
 539         ji->code_size = p - code_buffer;
 540         ji->code_start = g_memdup (code_buffer, p - code_buffer);
 541
 542         mono_jit_info_table_add (mono_get_root_domain (), ji);
 543
 544         return ji->code_start;
 545 }