arch/x86/mm/pf_in.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Fault Injection Test harness (FI)
   4  *  Copyright (C) Intel Crop.
   5  */
   6
   7 /*  Id: pf_in.c,v 1.1.1.1 2002/11/12 05:56:32 brlock Exp
   8  *  Copyright by Intel Crop., 2002
   9  *  Louis Zhuang (louis.zhuang@intel.com)
  10  *
  11  *  Bjorn Steinbrink (B.Steinbrink@gmx.de), 2007
  12  */
  13
  14 #include <linux/ptrace.h> /* struct pt_regs */
  15 #include "pf_in.h"
  16
  17 #ifdef __i386__
  18 /* IA32 Manual 3, 2-1 */
  19 static unsigned char prefix_codes[] = {
  20         0xF0, 0xF2, 0xF3, 0x2E, 0x36, 0x3E, 0x26, 0x64,
  21         0x65, 0x66, 0x67
  22 };
  23 /* IA32 Manual 3, 3-432*/
  24 static unsigned int reg_rop[] = {
  25         0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
  26 };
  27 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
  28 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
  29 /* IA32 Manual 3, 3-432*/
  30 static unsigned int rw8[] = { 0x88, 0x8A, 0xC6, 0xAA };
  31 static unsigned int rw32[] = {
  32         0x89, 0x8B, 0xC7, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
  33 };
  34 static unsigned int mw8[] = { 0x88, 0x8A, 0xC6, 0xB60F, 0xBE0F, 0xAA };
  35 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
  36 static unsigned int mw32[] = { 0x89, 0x8B, 0xC7, 0xAB };
  37 static unsigned int mw64[] = {};
  38 #else /* not __i386__ */
  39 static unsigned char prefix_codes[] = {
  40         0x66, 0x67, 0x2E, 0x3E, 0x26, 0x64, 0x65, 0x36,
  41         0xF0, 0xF3, 0xF2,
  42         /* REX Prefixes */
  43         0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
  44         0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f
  45 };
  46 /* AMD64 Manual 3, Appendix A*/
  47 static unsigned int reg_rop[] = {
  48         0x8A, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F
  49 };
  50 static unsigned int reg_wop[] = { 0x88, 0x89, 0xAA, 0xAB };
  51 static unsigned int imm_wop[] = { 0xC6, 0xC7 };
  52 static unsigned int rw8[] = { 0xC6, 0x88, 0x8A, 0xAA };
  53 static unsigned int rw32[] = {
  54         0xC7, 0x89, 0x8B, 0xB60F, 0xB70F, 0xBE0F, 0xBF0F, 0xAB
  55 };
  56 /* 8 bit only */
  57 static unsigned int mw8[] = { 0xC6, 0x88, 0x8A, 0xB60F, 0xBE0F, 0xAA };
  58 /* 16 bit only */
  59 static unsigned int mw16[] = { 0xB70F, 0xBF0F };
  60 /* 16 or 32 bit */
  61 static unsigned int mw32[] = { 0xC7 };
  62 /* 16, 32 or 64 bit */
  63 static unsigned int mw64[] = { 0x89, 0x8B, 0xAB };
  64 #endif /* not __i386__ */
  65
  66 struct prefix_bits {
  67         unsigned shorted:1;
  68         unsigned enlarged:1;
  69         unsigned rexr:1;
  70         unsigned rex:1;
  71 };
  72
  73 static int skip_prefix(unsigned char *addr, struct prefix_bits *prf)
  74 {
  75         int i;
  76         unsigned char *p = addr;
  77         prf->shorted = 0;
  78         prf->enlarged = 0;
  79         prf->rexr = 0;
  80         prf->rex = 0;
  81
  82 restart:
  83         for (i = 0; i < ARRAY_SIZE(prefix_codes); i++) {
  84                 if (*p == prefix_codes[i]) {
  85                         if (*p == 0x66)
  86                                 prf->shorted = 1;
  87 #ifdef __amd64__
  88                         if ((*p & 0xf8) == 0x48)
  89                                 prf->enlarged = 1;
  90                         if ((*p & 0xf4) == 0x44)
  91                                 prf->rexr = 1;
  92                         if ((*p & 0xf0) == 0x40)
  93                                 prf->rex = 1;
  94 #endif
  95                         p++;
  96                         goto restart;
  97                 }
  98         }
  99
 100         return (p - addr);
 101 }
 102
 103 static int get_opcode(unsigned char *addr, unsigned int *opcode)
 104 {
 105         int len;
 106
 107         if (*addr == 0x0F) {
 108                 /* 0x0F is extension instruction */
 109                 *opcode = *(unsigned short *)addr;
 110                 len = 2;
 111         } else {
 112                 *opcode = *addr;
 113                 len = 1;
 114         }
 115
 116         return len;
 117 }
 118
 119 #define CHECK_OP_TYPE(opcode, array, type) \
 120         for (i = 0; i < ARRAY_SIZE(array); i++) { \
 121                 if (array[i] == opcode) { \
 122                         rv = type; \
 123                         goto exit; \
 124                 } \
 125         }
 126
 127 enum reason_type get_ins_type(unsigned long ins_addr)
 128 {
 129         unsigned int opcode;
 130         unsigned char *p;
 131         struct prefix_bits prf;
 132         int i;
 133         enum reason_type rv = OTHERS;
 134
 135         p = (unsigned char *)ins_addr;
 136         p += skip_prefix(p, &prf);
 137         p += get_opcode(p, &opcode);
 138
 139         CHECK_OP_TYPE(opcode, reg_rop, REG_READ);
 140         CHECK_OP_TYPE(opcode, reg_wop, REG_WRITE);
 141         CHECK_OP_TYPE(opcode, imm_wop, IMM_WRITE);
 142
 143 exit:
 144         return rv;
 145 }
 146 #undef CHECK_OP_TYPE
 147
 148 static unsigned int get_ins_reg_width(unsigned long ins_addr)
 149 {
 150         unsigned int opcode;
 151         unsigned char *p;
 152         struct prefix_bits prf;
 153         int i;
 154
 155         p = (unsigned char *)ins_addr;
 156         p += skip_prefix(p, &prf);
 157         p += get_opcode(p, &opcode);
 158
 159         for (i = 0; i < ARRAY_SIZE(rw8); i++)
 160                 if (rw8[i] == opcode)
 161                         return 1;
 162
 163         for (i = 0; i < ARRAY_SIZE(rw32); i++)
 164                 if (rw32[i] == opcode)
 165                         return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
 166
 167         printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
 168         return 0;
 169 }
 170
 171 unsigned int get_ins_mem_width(unsigned long ins_addr)
 172 {
 173         unsigned int opcode;
 174         unsigned char *p;
 175         struct prefix_bits prf;
 176         int i;
 177
 178         p = (unsigned char *)ins_addr;
 179         p += skip_prefix(p, &prf);
 180         p += get_opcode(p, &opcode);
 181
 182         for (i = 0; i < ARRAY_SIZE(mw8); i++)
 183                 if (mw8[i] == opcode)
 184                         return 1;
 185
 186         for (i = 0; i < ARRAY_SIZE(mw16); i++)
 187                 if (mw16[i] == opcode)
 188                         return 2;
 189
 190         for (i = 0; i < ARRAY_SIZE(mw32); i++)
 191                 if (mw32[i] == opcode)
 192                         return prf.shorted ? 2 : 4;
 193
 194         for (i = 0; i < ARRAY_SIZE(mw64); i++)
 195                 if (mw64[i] == opcode)
 196                         return prf.shorted ? 2 : (prf.enlarged ? 8 : 4);
 197
 198         printk(KERN_ERR "mmiotrace: Unknown opcode 0x%02x\n", opcode);
 199         return 0;
 200 }
 201
 202 /*
 203  * Define register ident in mod/rm byte.
 204  * Note: these are NOT the same as in ptrace-abi.h.
 205  */
 206 enum {
 207         arg_AL = 0,
 208         arg_CL = 1,
 209         arg_DL = 2,
 210         arg_BL = 3,
 211         arg_AH = 4,
 212         arg_CH = 5,
 213         arg_DH = 6,
 214         arg_BH = 7,
 215
 216         arg_AX = 0,
 217         arg_CX = 1,
 218         arg_DX = 2,
 219         arg_BX = 3,
 220         arg_SP = 4,
 221         arg_BP = 5,
 222         arg_SI = 6,
 223         arg_DI = 7,
 224 #ifdef __amd64__
 225         arg_R8  = 8,
 226         arg_R9  = 9,
 227         arg_R10 = 10,
 228         arg_R11 = 11,
 229         arg_R12 = 12,
 230         arg_R13 = 13,
 231         arg_R14 = 14,
 232         arg_R15 = 15
 233 #endif
 234 };
 235
 236 static unsigned char *get_reg_w8(int no, int rex, struct pt_regs *regs)
 237 {
 238         unsigned char *rv = NULL;
 239
 240         switch (no) {
 241         case arg_AL:
 242                 rv = (unsigned char *)&regs->ax;
 243                 break;
 244         case arg_BL:
 245                 rv = (unsigned char *)&regs->bx;
 246                 break;
 247         case arg_CL:
 248                 rv = (unsigned char *)&regs->cx;
 249                 break;
 250         case arg_DL:
 251                 rv = (unsigned char *)&regs->dx;
 252                 break;
 253 #ifdef __amd64__
 254         case arg_R8:
 255                 rv = (unsigned char *)&regs->r8;
 256                 break;
 257         case arg_R9:
 258                 rv = (unsigned char *)&regs->r9;
 259                 break;
 260         case arg_R10:
 261                 rv = (unsigned char *)&regs->r10;
 262                 break;
 263         case arg_R11:
 264                 rv = (unsigned char *)&regs->r11;
 265                 break;
 266         case arg_R12:
 267                 rv = (unsigned char *)&regs->r12;
 268                 break;
 269         case arg_R13:
 270                 rv = (unsigned char *)&regs->r13;
 271                 break;
 272         case arg_R14:
 273                 rv = (unsigned char *)&regs->r14;
 274                 break;
 275         case arg_R15:
 276                 rv = (unsigned char *)&regs->r15;
 277                 break;
 278 #endif
 279         default:
 280                 break;
 281         }
 282
 283         if (rv)
 284                 return rv;
 285
 286         if (rex) {
 287                 /*
 288                  * If REX prefix exists, access low bytes of SI etc.
 289                  * instead of AH etc.
 290                  */
 291                 switch (no) {
 292                 case arg_SI:
 293                         rv = (unsigned char *)&regs->si;
 294                         break;
 295                 case arg_DI:
 296                         rv = (unsigned char *)&regs->di;
 297                         break;
 298                 case arg_BP:
 299                         rv = (unsigned char *)&regs->bp;
 300                         break;
 301                 case arg_SP:
 302                         rv = (unsigned char *)&regs->sp;
 303                         break;
 304                 default:
 305                         break;
 306                 }
 307         } else {
 308                 switch (no) {
 309                 case arg_AH:
 310                         rv = 1 + (unsigned char *)&regs->ax;
 311                         break;
 312                 case arg_BH:
 313                         rv = 1 + (unsigned char *)&regs->bx;
 314                         break;
 315                 case arg_CH:
 316                         rv = 1 + (unsigned char *)&regs->cx;
 317                         break;
 318                 case arg_DH:
 319                         rv = 1 + (unsigned char *)&regs->dx;
 320                         break;
 321                 default:
 322                         break;
 323                 }
 324         }
 325
 326         if (!rv)
 327                 printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
 328
 329         return rv;
 330 }
 331
 332 static unsigned long *get_reg_w32(int no, struct pt_regs *regs)
 333 {
 334         unsigned long *rv = NULL;
 335
 336         switch (no) {
 337         case arg_AX:
 338                 rv = &regs->ax;
 339                 break;
 340         case arg_BX:
 341                 rv = &regs->bx;
 342                 break;
 343         case arg_CX:
 344                 rv = &regs->cx;
 345                 break;
 346         case arg_DX:
 347                 rv = &regs->dx;
 348                 break;
 349         case arg_SP:
 350                 rv = &regs->sp;
 351                 break;
 352         case arg_BP:
 353                 rv = &regs->bp;
 354                 break;
 355         case arg_SI:
 356                 rv = &regs->si;
 357                 break;
 358         case arg_DI:
 359                 rv = &regs->di;
 360                 break;
 361 #ifdef __amd64__
 362         case arg_R8:
 363                 rv = &regs->r8;
 364                 break;
 365         case arg_R9:
 366                 rv = &regs->r9;
 367                 break;
 368         case arg_R10:
 369                 rv = &regs->r10;
 370                 break;
 371         case arg_R11:
 372                 rv = &regs->r11;
 373                 break;
 374         case arg_R12:
 375                 rv = &regs->r12;
 376                 break;
 377         case arg_R13:
 378                 rv = &regs->r13;
 379                 break;
 380         case arg_R14:
 381                 rv = &regs->r14;
 382                 break;
 383         case arg_R15:
 384                 rv = &regs->r15;
 385                 break;
 386 #endif
 387         default:
 388                 printk(KERN_ERR "mmiotrace: Error reg no# %d\n", no);
 389         }
 390
 391         return rv;
 392 }
 393
 394 unsigned long get_ins_reg_val(unsigned long ins_addr, struct pt_regs *regs)
 395 {
 396         unsigned int opcode;
 397         int reg;
 398         unsigned char *p;
 399         struct prefix_bits prf;
 400         int i;
 401
 402         p = (unsigned char *)ins_addr;
 403         p += skip_prefix(p, &prf);
 404         p += get_opcode(p, &opcode);
 405         for (i = 0; i < ARRAY_SIZE(reg_rop); i++)
 406                 if (reg_rop[i] == opcode)
 407                         goto do_work;
 408
 409         for (i = 0; i < ARRAY_SIZE(reg_wop); i++)
 410                 if (reg_wop[i] == opcode)
 411                         goto do_work;
 412
 413         printk(KERN_ERR "mmiotrace: Not a register instruction, opcode "
 414                                                         "0x%02x\n", opcode);
 415         goto err;
 416
 417 do_work:
 418         /* for STOS, source register is fixed */
 419         if (opcode == 0xAA || opcode == 0xAB) {
 420                 reg = arg_AX;
 421         } else {
 422                 unsigned char mod_rm = *p;
 423                 reg = ((mod_rm >> 3) & 0x7) | (prf.rexr << 3);
 424         }
 425         switch (get_ins_reg_width(ins_addr)) {
 426         case 1:
 427                 return *get_reg_w8(reg, prf.rex, regs);
 428
 429         case 2:
 430                 return *(unsigned short *)get_reg_w32(reg, regs);
 431
 432         case 4:
 433                 return *(unsigned int *)get_reg_w32(reg, regs);
 434
 435 #ifdef __amd64__
 436         case 8:
 437                 return *(unsigned long *)get_reg_w32(reg, regs);
 438 #endif
 439
 440         default:
 441                 printk(KERN_ERR "mmiotrace: Error width# %d\n", reg);
 442         }
 443
 444 err:
 445         return 0;
 446 }
 447
 448 unsigned long get_ins_imm_val(unsigned long ins_addr)
 449 {
 450         unsigned int opcode;
 451         unsigned char mod_rm;
 452         unsigned char mod;
 453         unsigned char *p;
 454         struct prefix_bits prf;
 455         int i;
 456
 457         p = (unsigned char *)ins_addr;
 458         p += skip_prefix(p, &prf);
 459         p += get_opcode(p, &opcode);
 460         for (i = 0; i < ARRAY_SIZE(imm_wop); i++)
 461                 if (imm_wop[i] == opcode)
 462                         goto do_work;
 463
 464         printk(KERN_ERR "mmiotrace: Not an immediate instruction, opcode "
 465                                                         "0x%02x\n", opcode);
 466         goto err;
 467
 468 do_work:
 469         mod_rm = *p;
 470         mod = mod_rm >> 6;
 471         p++;
 472         switch (mod) {
 473         case 0:
 474                 /* if r/m is 5 we have a 32 disp (IA32 Manual 3, Table 2-2)  */
 475                 /* AMD64: XXX Check for address size prefix? */
 476                 if ((mod_rm & 0x7) == 0x5)
 477                         p += 4;
 478                 break;
 479
 480         case 1:
 481                 p += 1;
 482                 break;
 483
 484         case 2:
 485                 p += 4;
 486                 break;
 487
 488         case 3:
 489         default:
 490                 printk(KERN_ERR "mmiotrace: not a memory access instruction "
 491                                                 "at 0x%lx, rm_mod=0x%02x\n",
 492                                                 ins_addr, mod_rm);
 493         }
 494
 495         switch (get_ins_reg_width(ins_addr)) {
 496         case 1:
 497                 return *(unsigned char *)p;
 498
 499         case 2:
 500                 return *(unsigned short *)p;
 501
 502         case 4:
 503                 return *(unsigned int *)p;
 504
 505 #ifdef __amd64__
 506         case 8:
 507                 return *(unsigned long *)p;
 508 #endif
 509
 510         default:
 511                 printk(KERN_ERR "mmiotrace: Error: width.\n");
 512         }
 513
 514 err:
 515         return 0;
 516 }