arch/powerpc/lib/sstep.c

   1 /*
   2  * Single-step support.
   3  *
   4  * Copyright (C) 2004 Paul Mackerras <paulus@au.ibm.com>, IBM
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/kprobes.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/prefetch.h>
  15 #include <asm/sstep.h>
  16 #include <asm/processor.h>
  17 #include <linux/uaccess.h>
  18 #include <asm/cpu_has_feature.h>
  19 #include <asm/cputable.h>
  20
  21 extern char system_call_common[];
  22
  23 #ifdef CONFIG_PPC64
  24 /* Bits in SRR1 that are copied from MSR */
  25 #define MSR_MASK        0xffffffff87c0ffffUL
  26 #else
  27 #define MSR_MASK        0x87c0ffff
  28 #endif
  29
  30 /* Bits in XER */
  31 #define XER_SO          0x80000000U
  32 #define XER_OV          0x40000000U
  33 #define XER_CA          0x20000000U
  34
  35 #ifdef CONFIG_PPC_FPU
  36 /*
  37  * Functions in ldstfp.S
  38  */
  39 extern int do_lfs(int rn, unsigned long ea);
  40 extern int do_lfd(int rn, unsigned long ea);
  41 extern int do_stfs(int rn, unsigned long ea);
  42 extern int do_stfd(int rn, unsigned long ea);
  43 extern int do_lvx(int rn, unsigned long ea);
  44 extern int do_stvx(int rn, unsigned long ea);
  45 extern int do_lxvd2x(int rn, unsigned long ea);
  46 extern int do_stxvd2x(int rn, unsigned long ea);
  47 #endif
  48
  49 /*
  50  * Emulate the truncation of 64 bit values in 32-bit mode.
  51  */
  52 static unsigned long truncate_if_32bit(unsigned long msr, unsigned long val)
  53 {
  54 #ifdef __powerpc64__
  55         if ((msr & MSR_64BIT) == 0)
  56                 val &= 0xffffffffUL;
  57 #endif
  58         return val;
  59 }
  60
  61 /*
  62  * Determine whether a conditional branch instruction would branch.
  63  */
  64 static int __kprobes branch_taken(unsigned int instr, struct pt_regs *regs)
  65 {
  66         unsigned int bo = (instr >> 21) & 0x1f;
  67         unsigned int bi;
  68
  69         if ((bo & 4) == 0) {
  70                 /* decrement counter */
  71                 --regs->ctr;
  72                 if (((bo >> 1) & 1) ^ (regs->ctr == 0))
  73                         return 0;
  74         }
  75         if ((bo & 0x10) == 0) {
  76                 /* check bit from CR */
  77                 bi = (instr >> 16) & 0x1f;
  78                 if (((regs->ccr >> (31 - bi)) & 1) != ((bo >> 3) & 1))
  79                         return 0;
  80         }
  81         return 1;
  82 }
  83
  84
  85 static long __kprobes address_ok(struct pt_regs *regs, unsigned long ea, int nb)
  86 {
  87         if (!user_mode(regs))
  88                 return 1;
  89         return __access_ok(ea, nb, USER_DS);
  90 }
  91
  92 /*
  93  * Calculate effective address for a D-form instruction
  94  */
  95 static unsigned long __kprobes dform_ea(unsigned int instr, struct pt_regs *regs)
  96 {
  97         int ra;
  98         unsigned long ea;
  99
 100         ra = (instr >> 16) & 0x1f;
 101         ea = (signed short) instr;              /* sign-extend */
 102         if (ra)
 103                 ea += regs->gpr[ra];
 104
 105         return truncate_if_32bit(regs->msr, ea);
 106 }
 107
 108 #ifdef __powerpc64__
 109 /*
 110  * Calculate effective address for a DS-form instruction
 111  */
 112 static unsigned long __kprobes dsform_ea(unsigned int instr, struct pt_regs *regs)
 113 {
 114         int ra;
 115         unsigned long ea;
 116
 117         ra = (instr >> 16) & 0x1f;
 118         ea = (signed short) (instr & ~3);       /* sign-extend */
 119         if (ra)
 120                 ea += regs->gpr[ra];
 121
 122         return truncate_if_32bit(regs->msr, ea);
 123 }
 124 #endif /* __powerpc64 */
 125
 126 /*
 127  * Calculate effective address for an X-form instruction
 128  */
 129 static unsigned long __kprobes xform_ea(unsigned int instr,
 130                                         struct pt_regs *regs)
 131 {
 132         int ra, rb;
 133         unsigned long ea;
 134
 135         ra = (instr >> 16) & 0x1f;
 136         rb = (instr >> 11) & 0x1f;
 137         ea = regs->gpr[rb];
 138         if (ra)
 139                 ea += regs->gpr[ra];
 140
 141         return truncate_if_32bit(regs->msr, ea);
 142 }
 143
 144 /*
 145  * Return the largest power of 2, not greater than sizeof(unsigned long),
 146  * such that x is a multiple of it.
 147  */
 148 static inline unsigned long max_align(unsigned long x)
 149 {
 150         x |= sizeof(unsigned long);
 151         return x & -x;          /* isolates rightmost bit */
 152 }
 153
 154
 155 static inline unsigned long byterev_2(unsigned long x)
 156 {
 157         return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
 158 }
 159
 160 static inline unsigned long byterev_4(unsigned long x)
 161 {
 162         return ((x >> 24) & 0xff) | ((x >> 8) & 0xff00) |
 163                 ((x & 0xff00) << 8) | ((x & 0xff) << 24);
 164 }
 165
 166 #ifdef __powerpc64__
 167 static inline unsigned long byterev_8(unsigned long x)
 168 {
 169         return (byterev_4(x) << 32) | byterev_4(x >> 32);
 170 }
 171 #endif
 172
 173 static int __kprobes read_mem_aligned(unsigned long *dest, unsigned long ea,
 174                                       int nb)
 175 {
 176         int err = 0;
 177         unsigned long x = 0;
 178
 179         switch (nb) {
 180         case 1:
 181                 err = __get_user(x, (unsigned char __user *) ea);
 182                 break;
 183         case 2:
 184                 err = __get_user(x, (unsigned short __user *) ea);
 185                 break;
 186         case 4:
 187                 err = __get_user(x, (unsigned int __user *) ea);
 188                 break;
 189 #ifdef __powerpc64__
 190         case 8:
 191                 err = __get_user(x, (unsigned long __user *) ea);
 192                 break;
 193 #endif
 194         }
 195         if (!err)
 196                 *dest = x;
 197         return err;
 198 }
 199
 200 static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
 201                                         int nb, struct pt_regs *regs)
 202 {
 203         int err;
 204         unsigned long x, b, c;
 205 #ifdef __LITTLE_ENDIAN__
 206         int len = nb; /* save a copy of the length for byte reversal */
 207 #endif
 208
 209         /* unaligned, do this in pieces */
 210         x = 0;
 211         for (; nb > 0; nb -= c) {
 212 #ifdef __LITTLE_ENDIAN__
 213                 c = 1;
 214 #endif
 215 #ifdef __BIG_ENDIAN__
 216                 c = max_align(ea);
 217 #endif
 218                 if (c > nb)
 219                         c = max_align(nb);
 220                 err = read_mem_aligned(&b, ea, c);
 221                 if (err)
 222                         return err;
 223                 x = (x << (8 * c)) + b;
 224                 ea += c;
 225         }
 226 #ifdef __LITTLE_ENDIAN__
 227         switch (len) {
 228         case 2:
 229                 *dest = byterev_2(x);
 230                 break;
 231         case 4:
 232                 *dest = byterev_4(x);
 233                 break;
 234 #ifdef __powerpc64__
 235         case 8:
 236                 *dest = byterev_8(x);
 237                 break;
 238 #endif
 239         }
 240 #endif
 241 #ifdef __BIG_ENDIAN__
 242         *dest = x;
 243 #endif
 244         return 0;
 245 }
 246
 247 /*
 248  * Read memory at address ea for nb bytes, return 0 for success
 249  * or -EFAULT if an error occurred.
 250  */
 251 static int __kprobes read_mem(unsigned long *dest, unsigned long ea, int nb,
 252                               struct pt_regs *regs)
 253 {
 254         if (!address_ok(regs, ea, nb))
 255                 return -EFAULT;
 256         if ((ea & (nb - 1)) == 0)
 257                 return read_mem_aligned(dest, ea, nb);
 258         return read_mem_unaligned(dest, ea, nb, regs);
 259 }
 260
 261 static int __kprobes write_mem_aligned(unsigned long val, unsigned long ea,
 262                                        int nb)
 263 {
 264         int err = 0;
 265
 266         switch (nb) {
 267         case 1:
 268                 err = __put_user(val, (unsigned char __user *) ea);
 269                 break;
 270         case 2:
 271                 err = __put_user(val, (unsigned short __user *) ea);
 272                 break;
 273         case 4:
 274                 err = __put_user(val, (unsigned int __user *) ea);
 275                 break;
 276 #ifdef __powerpc64__
 277         case 8:
 278                 err = __put_user(val, (unsigned long __user *) ea);
 279                 break;
 280 #endif
 281         }
 282         return err;
 283 }
 284
 285 static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
 286                                          int nb, struct pt_regs *regs)
 287 {
 288         int err;
 289         unsigned long c;
 290
 291 #ifdef __LITTLE_ENDIAN__
 292         switch (nb) {
 293         case 2:
 294                 val = byterev_2(val);
 295                 break;
 296         case 4:
 297                 val = byterev_4(val);
 298                 break;
 299 #ifdef __powerpc64__
 300         case 8:
 301                 val = byterev_8(val);
 302                 break;
 303 #endif
 304         }
 305 #endif
 306         /* unaligned or little-endian, do this in pieces */
 307         for (; nb > 0; nb -= c) {
 308 #ifdef __LITTLE_ENDIAN__
 309                 c = 1;
 310 #endif
 311 #ifdef __BIG_ENDIAN__
 312                 c = max_align(ea);
 313 #endif
 314                 if (c > nb)
 315                         c = max_align(nb);
 316                 err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
 317                 if (err)
 318                         return err;
 319                 ea += c;
 320         }
 321         return 0;
 322 }
 323
 324 /*
 325  * Write memory at address ea for nb bytes, return 0 for success
 326  * or -EFAULT if an error occurred.
 327  */
 328 static int __kprobes write_mem(unsigned long val, unsigned long ea, int nb,
 329                                struct pt_regs *regs)
 330 {
 331         if (!address_ok(regs, ea, nb))
 332                 return -EFAULT;
 333         if ((ea & (nb - 1)) == 0)
 334                 return write_mem_aligned(val, ea, nb);
 335         return write_mem_unaligned(val, ea, nb, regs);
 336 }
 337
 338 #ifdef CONFIG_PPC_FPU
 339 /*
 340  * Check the address and alignment, and call func to do the actual
 341  * load or store.
 342  */
 343 static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
 344                                 unsigned long ea, int nb,
 345                                 struct pt_regs *regs)
 346 {
 347         int err;
 348         union {
 349                 double dbl;
 350                 unsigned long ul[2];
 351                 struct {
 352 #ifdef __BIG_ENDIAN__
 353                         unsigned _pad_;
 354                         unsigned word;
 355 #endif
 356 #ifdef __LITTLE_ENDIAN__
 357                         unsigned word;
 358                         unsigned _pad_;
 359 #endif
 360                 } single;
 361         } data;
 362         unsigned long ptr;
 363
 364         if (!address_ok(regs, ea, nb))
 365                 return -EFAULT;
 366         if ((ea & 3) == 0)
 367                 return (*func)(rn, ea);
 368         ptr = (unsigned long) &data.ul;
 369         if (sizeof(unsigned long) == 8 || nb == 4) {
 370                 err = read_mem_unaligned(&data.ul[0], ea, nb, regs);
 371                 if (nb == 4)
 372                         ptr = (unsigned long)&(data.single.word);
 373         } else {
 374                 /* reading a double on 32-bit */
 375                 err = read_mem_unaligned(&data.ul[0], ea, 4, regs);
 376                 if (!err)
 377                         err = read_mem_unaligned(&data.ul[1], ea + 4, 4, regs);
 378         }
 379         if (err)
 380                 return err;
 381         return (*func)(rn, ptr);
 382 }
 383
 384 static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
 385                                  unsigned long ea, int nb,
 386                                  struct pt_regs *regs)
 387 {
 388         int err;
 389         union {
 390                 double dbl;
 391                 unsigned long ul[2];
 392                 struct {
 393 #ifdef __BIG_ENDIAN__
 394                         unsigned _pad_;
 395                         unsigned word;
 396 #endif
 397 #ifdef __LITTLE_ENDIAN__
 398                         unsigned word;
 399                         unsigned _pad_;
 400 #endif
 401                 } single;
 402         } data;
 403         unsigned long ptr;
 404
 405         if (!address_ok(regs, ea, nb))
 406                 return -EFAULT;
 407         if ((ea & 3) == 0)
 408                 return (*func)(rn, ea);
 409         ptr = (unsigned long) &data.ul[0];
 410         if (sizeof(unsigned long) == 8 || nb == 4) {
 411                 if (nb == 4)
 412                         ptr = (unsigned long)&(data.single.word);
 413                 err = (*func)(rn, ptr);
 414                 if (err)
 415                         return err;
 416                 err = write_mem_unaligned(data.ul[0], ea, nb, regs);
 417         } else {
 418                 /* writing a double on 32-bit */
 419                 err = (*func)(rn, ptr);
 420                 if (err)
 421                         return err;
 422                 err = write_mem_unaligned(data.ul[0], ea, 4, regs);
 423                 if (!err)
 424                         err = write_mem_unaligned(data.ul[1], ea + 4, 4, regs);
 425         }
 426         return err;
 427 }
 428 #endif
 429
 430 #ifdef CONFIG_ALTIVEC
 431 /* For Altivec/VMX, no need to worry about alignment */
 432 static int __kprobes do_vec_load(int rn, int (*func)(int, unsigned long),
 433                                  unsigned long ea, struct pt_regs *regs)
 434 {
 435         if (!address_ok(regs, ea & ~0xfUL, 16))
 436                 return -EFAULT;
 437         return (*func)(rn, ea);
 438 }
 439
 440 static int __kprobes do_vec_store(int rn, int (*func)(int, unsigned long),
 441                                   unsigned long ea, struct pt_regs *regs)
 442 {
 443         if (!address_ok(regs, ea & ~0xfUL, 16))
 444                 return -EFAULT;
 445         return (*func)(rn, ea);
 446 }
 447 #endif /* CONFIG_ALTIVEC */
 448
 449 #ifdef CONFIG_VSX
 450 static int __kprobes do_vsx_load(int rn, int (*func)(int, unsigned long),
 451                                  unsigned long ea, struct pt_regs *regs)
 452 {
 453         int err;
 454         unsigned long val[2];
 455
 456         if (!address_ok(regs, ea, 16))
 457                 return -EFAULT;
 458         if ((ea & 3) == 0)
 459                 return (*func)(rn, ea);
 460         err = read_mem_unaligned(&val[0], ea, 8, regs);
 461         if (!err)
 462                 err = read_mem_unaligned(&val[1], ea + 8, 8, regs);
 463         if (!err)
 464                 err = (*func)(rn, (unsigned long) &val[0]);
 465         return err;
 466 }
 467
 468 static int __kprobes do_vsx_store(int rn, int (*func)(int, unsigned long),
 469                                  unsigned long ea, struct pt_regs *regs)
 470 {
 471         int err;
 472         unsigned long val[2];
 473
 474         if (!address_ok(regs, ea, 16))
 475                 return -EFAULT;
 476         if ((ea & 3) == 0)
 477                 return (*func)(rn, ea);
 478         err = (*func)(rn, (unsigned long) &val[0]);
 479         if (err)
 480                 return err;
 481         err = write_mem_unaligned(val[0], ea, 8, regs);
 482         if (!err)
 483                 err = write_mem_unaligned(val[1], ea + 8, 8, regs);
 484         return err;
 485 }
 486 #endif /* CONFIG_VSX */
 487
 488 #define __put_user_asmx(x, addr, err, op, cr)           \
 489         __asm__ __volatile__(                           \
 490                 "1:     " op " %2,0,%3\n"               \
 491                 "       mfcr    %1\n"                   \
 492                 "2:\n"                                  \
 493                 ".section .fixup,\"ax\"\n"              \
 494                 "3:     li      %0,%4\n"                \
 495                 "       b       2b\n"                   \
 496                 ".previous\n"                           \
 497                 EX_TABLE(1b, 3b)                        \
 498                 : "=r" (err), "=r" (cr)                 \
 499                 : "r" (x), "r" (addr), "i" (-EFAULT), "0" (err))
 500
 501 #define __get_user_asmx(x, addr, err, op)               \
 502         __asm__ __volatile__(                           \
 503                 "1:     "op" %1,0,%2\n"                 \
 504                 "2:\n"                                  \
 505                 ".section .fixup,\"ax\"\n"              \
 506                 "3:     li      %0,%3\n"                \
 507                 "       b       2b\n"                   \
 508                 ".previous\n"                           \
 509                 EX_TABLE(1b, 3b)                        \
 510                 : "=r" (err), "=r" (x)                  \
 511                 : "r" (addr), "i" (-EFAULT), "0" (err))
 512
 513 #define __cacheop_user_asmx(addr, err, op)              \
 514         __asm__ __volatile__(                           \
 515                 "1:     "op" 0,%1\n"                    \
 516                 "2:\n"                                  \
 517                 ".section .fixup,\"ax\"\n"              \
 518                 "3:     li      %0,%3\n"                \
 519                 "       b       2b\n"                   \
 520                 ".previous\n"                           \
 521                 EX_TABLE(1b, 3b)                        \
 522                 : "=r" (err)                            \
 523                 : "r" (addr), "i" (-EFAULT), "0" (err))
 524
 525 static void __kprobes set_cr0(struct pt_regs *regs, int rd)
 526 {
 527         long val = regs->gpr[rd];
 528
 529         regs->ccr = (regs->ccr & 0x0fffffff) | ((regs->xer >> 3) & 0x10000000);
 530 #ifdef __powerpc64__
 531         if (!(regs->msr & MSR_64BIT))
 532                 val = (int) val;
 533 #endif
 534         if (val < 0)
 535                 regs->ccr |= 0x80000000;
 536         else if (val > 0)
 537                 regs->ccr |= 0x40000000;
 538         else
 539                 regs->ccr |= 0x20000000;
 540 }
 541
 542 static void __kprobes add_with_carry(struct pt_regs *regs, int rd,
 543                                      unsigned long val1, unsigned long val2,
 544                                      unsigned long carry_in)
 545 {
 546         unsigned long val = val1 + val2;
 547
 548         if (carry_in)
 549                 ++val;
 550         regs->gpr[rd] = val;
 551 #ifdef __powerpc64__
 552         if (!(regs->msr & MSR_64BIT)) {
 553                 val = (unsigned int) val;
 554                 val1 = (unsigned int) val1;
 555         }
 556 #endif
 557         if (val < val1 || (carry_in && val == val1))
 558                 regs->xer |= XER_CA;
 559         else
 560                 regs->xer &= ~XER_CA;
 561 }
 562
 563 static void __kprobes do_cmp_signed(struct pt_regs *regs, long v1, long v2,
 564                                     int crfld)
 565 {
 566         unsigned int crval, shift;
 567
 568         crval = (regs->xer >> 31) & 1;          /* get SO bit */
 569         if (v1 < v2)
 570                 crval |= 8;
 571         else if (v1 > v2)
 572                 crval |= 4;
 573         else
 574                 crval |= 2;
 575         shift = (7 - crfld) * 4;
 576         regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
 577 }
 578
 579 static void __kprobes do_cmp_unsigned(struct pt_regs *regs, unsigned long v1,
 580                                       unsigned long v2, int crfld)
 581 {
 582         unsigned int crval, shift;
 583
 584         crval = (regs->xer >> 31) & 1;          /* get SO bit */
 585         if (v1 < v2)
 586                 crval |= 8;
 587         else if (v1 > v2)
 588                 crval |= 4;
 589         else
 590                 crval |= 2;
 591         shift = (7 - crfld) * 4;
 592         regs->ccr = (regs->ccr & ~(0xf << shift)) | (crval << shift);
 593 }
 594
 595 static int __kprobes trap_compare(long v1, long v2)
 596 {
 597         int ret = 0;
 598
 599         if (v1 < v2)
 600                 ret |= 0x10;
 601         else if (v1 > v2)
 602                 ret |= 0x08;
 603         else
 604                 ret |= 0x04;
 605         if ((unsigned long)v1 < (unsigned long)v2)
 606                 ret |= 0x02;
 607         else if ((unsigned long)v1 > (unsigned long)v2)
 608                 ret |= 0x01;
 609         return ret;
 610 }
 611
 612 /*
 613  * Elements of 32-bit rotate and mask instructions.
 614  */
 615 #define MASK32(mb, me)  ((0xffffffffUL >> (mb)) + \
 616                          ((signed long)-0x80000000L >> (me)) + ((me) >= (mb)))
 617 #ifdef __powerpc64__
 618 #define MASK64_L(mb)    (~0UL >> (mb))
 619 #define MASK64_R(me)    ((signed long)-0x8000000000000000L >> (me))
 620 #define MASK64(mb, me)  (MASK64_L(mb) + MASK64_R(me) + ((me) >= (mb)))
 621 #define DATA32(x)       (((x) & 0xffffffffUL) | (((x) & 0xffffffffUL) << 32))
 622 #else
 623 #define DATA32(x)       (x)
 624 #endif
 625 #define ROTATE(x, n)    ((n) ? (((x) << (n)) | ((x) >> (8 * sizeof(long) - (n)))) : (x))
 626
 627 /*
 628  * Decode an instruction, and execute it if that can be done just by
 629  * modifying *regs (i.e. integer arithmetic and logical instructions,
 630  * branches, and barrier instructions).
 631  * Returns 1 if the instruction has been executed, or 0 if not.
 632  * Sets *op to indicate what the instruction does.
 633  */
 634 int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
 635                             unsigned int instr)
 636 {
 637         unsigned int opcode, ra, rb, rd, spr, u;
 638         unsigned long int imm;
 639         unsigned long int val, val2;
 640         unsigned int mb, me, sh;
 641         long ival;
 642
 643         op->type = COMPUTE;
 644
 645         opcode = instr >> 26;
 646         switch (opcode) {
 647         case 16:        /* bc */
 648                 op->type = BRANCH;
 649                 imm = (signed short)(instr & 0xfffc);
 650                 if ((instr & 2) == 0)
 651                         imm += regs->nip;
 652                 regs->nip += 4;
 653                 regs->nip = truncate_if_32bit(regs->msr, regs->nip);
 654                 if (instr & 1)
 655                         regs->link = regs->nip;
 656                 if (branch_taken(instr, regs))
 657                         regs->nip = truncate_if_32bit(regs->msr, imm);
 658                 return 1;
 659 #ifdef CONFIG_PPC64
 660         case 17:        /* sc */
 661                 if ((instr & 0xfe2) == 2)
 662                         op->type = SYSCALL;
 663                 else
 664                         op->type = UNKNOWN;
 665                 return 0;
 666 #endif
 667         case 18:        /* b */
 668                 op->type = BRANCH;
 669                 imm = instr & 0x03fffffc;
 670                 if (imm & 0x02000000)
 671                         imm -= 0x04000000;
 672                 if ((instr & 2) == 0)
 673                         imm += regs->nip;
 674                 if (instr & 1)
 675                         regs->link = truncate_if_32bit(regs->msr, regs->nip + 4);
 676                 imm = truncate_if_32bit(regs->msr, imm);
 677                 regs->nip = imm;
 678                 return 1;
 679         case 19:
 680                 switch ((instr >> 1) & 0x3ff) {
 681                 case 0:         /* mcrf */
 682                         rd = (instr >> 21) & 0x1c;
 683                         ra = (instr >> 16) & 0x1c;
 684                         val = (regs->ccr >> ra) & 0xf;
 685                         regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd);
 686                         goto instr_done;
 687
 688                 case 16:        /* bclr */
 689                 case 528:       /* bcctr */
 690                         op->type = BRANCH;
 691                         imm = (instr & 0x400)? regs->ctr: regs->link;
 692                         regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
 693                         imm = truncate_if_32bit(regs->msr, imm);
 694                         if (instr & 1)
 695                                 regs->link = regs->nip;
 696                         if (branch_taken(instr, regs))
 697                                 regs->nip = imm;
 698                         return 1;
 699
 700                 case 18:        /* rfid, scary */
 701                         if (regs->msr & MSR_PR)
 702                                 goto priv;
 703                         op->type = RFI;
 704                         return 0;
 705
 706                 case 150:       /* isync */
 707                         op->type = BARRIER;
 708                         isync();
 709                         goto instr_done;
 710
 711                 case 33:        /* crnor */
 712                 case 129:       /* crandc */
 713                 case 193:       /* crxor */
 714                 case 225:       /* crnand */
 715                 case 257:       /* crand */
 716                 case 289:       /* creqv */
 717                 case 417:       /* crorc */
 718                 case 449:       /* cror */
 719                         ra = (instr >> 16) & 0x1f;
 720                         rb = (instr >> 11) & 0x1f;
 721                         rd = (instr >> 21) & 0x1f;
 722                         ra = (regs->ccr >> (31 - ra)) & 1;
 723                         rb = (regs->ccr >> (31 - rb)) & 1;
 724                         val = (instr >> (6 + ra * 2 + rb)) & 1;
 725                         regs->ccr = (regs->ccr & ~(1UL << (31 - rd))) |
 726                                 (val << (31 - rd));
 727                         goto instr_done;
 728                 }
 729                 break;
 730         case 31:
 731                 switch ((instr >> 1) & 0x3ff) {
 732                 case 598:       /* sync */
 733                         op->type = BARRIER;
 734 #ifdef __powerpc64__
 735                         switch ((instr >> 21) & 3) {
 736                         case 1:         /* lwsync */
 737                                 asm volatile("lwsync" : : : "memory");
 738                                 goto instr_done;
 739                         case 2:         /* ptesync */
 740                                 asm volatile("ptesync" : : : "memory");
 741                                 goto instr_done;
 742                         }
 743 #endif
 744                         mb();
 745                         goto instr_done;
 746
 747                 case 854:       /* eieio */
 748                         op->type = BARRIER;
 749                         eieio();
 750                         goto instr_done;
 751                 }
 752                 break;
 753         }
 754
 755         /* Following cases refer to regs->gpr[], so we need all regs */
 756         if (!FULL_REGS(regs))
 757                 return 0;
 758
 759         rd = (instr >> 21) & 0x1f;
 760         ra = (instr >> 16) & 0x1f;
 761         rb = (instr >> 11) & 0x1f;
 762
 763         switch (opcode) {
 764 #ifdef __powerpc64__
 765         case 2:         /* tdi */
 766                 if (rd & trap_compare(regs->gpr[ra], (short) instr))
 767                         goto trap;
 768                 goto instr_done;
 769 #endif
 770         case 3:         /* twi */
 771                 if (rd & trap_compare((int)regs->gpr[ra], (short) instr))
 772                         goto trap;
 773                 goto instr_done;
 774
 775         case 7:         /* mulli */
 776                 regs->gpr[rd] = regs->gpr[ra] * (short) instr;
 777                 goto instr_done;
 778
 779         case 8:         /* subfic */
 780                 imm = (short) instr;
 781                 add_with_carry(regs, rd, ~regs->gpr[ra], imm, 1);
 782                 goto instr_done;
 783
 784         case 10:        /* cmpli */
 785                 imm = (unsigned short) instr;
 786                 val = regs->gpr[ra];
 787 #ifdef __powerpc64__
 788                 if ((rd & 1) == 0)
 789                         val = (unsigned int) val;
 790 #endif
 791                 do_cmp_unsigned(regs, val, imm, rd >> 2);
 792                 goto instr_done;
 793
 794         case 11:        /* cmpi */
 795                 imm = (short) instr;
 796                 val = regs->gpr[ra];
 797 #ifdef __powerpc64__
 798                 if ((rd & 1) == 0)
 799                         val = (int) val;
 800 #endif
 801                 do_cmp_signed(regs, val, imm, rd >> 2);
 802                 goto instr_done;
 803
 804         case 12:        /* addic */
 805                 imm = (short) instr;
 806                 add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
 807                 goto instr_done;
 808
 809         case 13:        /* addic. */
 810                 imm = (short) instr;
 811                 add_with_carry(regs, rd, regs->gpr[ra], imm, 0);
 812                 set_cr0(regs, rd);
 813                 goto instr_done;
 814
 815         case 14:        /* addi */
 816                 imm = (short) instr;
 817                 if (ra)
 818                         imm += regs->gpr[ra];
 819                 regs->gpr[rd] = imm;
 820                 goto instr_done;
 821
 822         case 15:        /* addis */
 823                 imm = ((short) instr) << 16;
 824                 if (ra)
 825                         imm += regs->gpr[ra];
 826                 regs->gpr[rd] = imm;
 827                 goto instr_done;
 828
 829         case 20:        /* rlwimi */
 830                 mb = (instr >> 6) & 0x1f;
 831                 me = (instr >> 1) & 0x1f;
 832                 val = DATA32(regs->gpr[rd]);
 833                 imm = MASK32(mb, me);
 834                 regs->gpr[ra] = (regs->gpr[ra] & ~imm) | (ROTATE(val, rb) & imm);
 835                 goto logical_done;
 836
 837         case 21:        /* rlwinm */
 838                 mb = (instr >> 6) & 0x1f;
 839                 me = (instr >> 1) & 0x1f;
 840                 val = DATA32(regs->gpr[rd]);
 841                 regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
 842                 goto logical_done;
 843
 844         case 23:        /* rlwnm */
 845                 mb = (instr >> 6) & 0x1f;
 846                 me = (instr >> 1) & 0x1f;
 847                 rb = regs->gpr[rb] & 0x1f;
 848                 val = DATA32(regs->gpr[rd]);
 849                 regs->gpr[ra] = ROTATE(val, rb) & MASK32(mb, me);
 850                 goto logical_done;
 851
 852         case 24:        /* ori */
 853                 imm = (unsigned short) instr;
 854                 regs->gpr[ra] = regs->gpr[rd] | imm;
 855                 goto instr_done;
 856
 857         case 25:        /* oris */
 858                 imm = (unsigned short) instr;
 859                 regs->gpr[ra] = regs->gpr[rd] | (imm << 16);
 860                 goto instr_done;
 861
 862         case 26:        /* xori */
 863                 imm = (unsigned short) instr;
 864                 regs->gpr[ra] = regs->gpr[rd] ^ imm;
 865                 goto instr_done;
 866
 867         case 27:        /* xoris */
 868                 imm = (unsigned short) instr;
 869                 regs->gpr[ra] = regs->gpr[rd] ^ (imm << 16);
 870                 goto instr_done;
 871
 872         case 28:        /* andi. */
 873                 imm = (unsigned short) instr;
 874                 regs->gpr[ra] = regs->gpr[rd] & imm;
 875                 set_cr0(regs, ra);
 876                 goto instr_done;
 877
 878         case 29:        /* andis. */
 879                 imm = (unsigned short) instr;
 880                 regs->gpr[ra] = regs->gpr[rd] & (imm << 16);
 881                 set_cr0(regs, ra);
 882                 goto instr_done;
 883
 884 #ifdef __powerpc64__
 885         case 30:        /* rld* */
 886                 mb = ((instr >> 6) & 0x1f) | (instr & 0x20);
 887                 val = regs->gpr[rd];
 888                 if ((instr & 0x10) == 0) {
 889                         sh = rb | ((instr & 2) << 4);
 890                         val = ROTATE(val, sh);
 891                         switch ((instr >> 2) & 3) {
 892                         case 0:         /* rldicl */
 893                                 regs->gpr[ra] = val & MASK64_L(mb);
 894                                 goto logical_done;
 895                         case 1:         /* rldicr */
 896                                 regs->gpr[ra] = val & MASK64_R(mb);
 897                                 goto logical_done;
 898                         case 2:         /* rldic */
 899                                 regs->gpr[ra] = val & MASK64(mb, 63 - sh);
 900                                 goto logical_done;
 901                         case 3:         /* rldimi */
 902                                 imm = MASK64(mb, 63 - sh);
 903                                 regs->gpr[ra] = (regs->gpr[ra] & ~imm) |
 904                                         (val & imm);
 905                                 goto logical_done;
 906                         }
 907                 } else {
 908                         sh = regs->gpr[rb] & 0x3f;
 909                         val = ROTATE(val, sh);
 910                         switch ((instr >> 1) & 7) {
 911                         case 0:         /* rldcl */
 912                                 regs->gpr[ra] = val & MASK64_L(mb);
 913                                 goto logical_done;
 914                         case 1:         /* rldcr */
 915                                 regs->gpr[ra] = val & MASK64_R(mb);
 916                                 goto logical_done;
 917                         }
 918                 }
 919 #endif
 920         break; /* illegal instruction */
 921
 922         case 31:
 923                 switch ((instr >> 1) & 0x3ff) {
 924                 case 4:         /* tw */
 925                         if (rd == 0x1f ||
 926                             (rd & trap_compare((int)regs->gpr[ra],
 927                                                (int)regs->gpr[rb])))
 928                                 goto trap;
 929                         goto instr_done;
 930 #ifdef __powerpc64__
 931                 case 68:        /* td */
 932                         if (rd & trap_compare(regs->gpr[ra], regs->gpr[rb]))
 933                                 goto trap;
 934                         goto instr_done;
 935 #endif
 936                 case 83:        /* mfmsr */
 937                         if (regs->msr & MSR_PR)
 938                                 goto priv;
 939                         op->type = MFMSR;
 940                         op->reg = rd;
 941                         return 0;
 942                 case 146:       /* mtmsr */
 943                         if (regs->msr & MSR_PR)
 944                                 goto priv;
 945                         op->type = MTMSR;
 946                         op->reg = rd;
 947                         op->val = 0xffffffff & ~(MSR_ME | MSR_LE);
 948                         return 0;
 949 #ifdef CONFIG_PPC64
 950                 case 178:       /* mtmsrd */
 951                         if (regs->msr & MSR_PR)
 952                                 goto priv;
 953                         op->type = MTMSR;
 954                         op->reg = rd;
 955                         /* only MSR_EE and MSR_RI get changed if bit 15 set */
 956                         /* mtmsrd doesn't change MSR_HV, MSR_ME or MSR_LE */
 957                         imm = (instr & 0x10000)? 0x8002: 0xefffffffffffeffeUL;
 958                         op->val = imm;
 959                         return 0;
 960 #endif
 961
 962                 case 19:        /* mfcr */
 963                         regs->gpr[rd] = regs->ccr;
 964                         regs->gpr[rd] &= 0xffffffffUL;
 965                         goto instr_done;
 966
 967                 case 144:       /* mtcrf */
 968                         imm = 0xf0000000UL;
 969                         val = regs->gpr[rd];
 970                         for (sh = 0; sh < 8; ++sh) {
 971                                 if (instr & (0x80000 >> sh))
 972                                         regs->ccr = (regs->ccr & ~imm) |
 973                                                 (val & imm);
 974                                 imm >>= 4;
 975                         }
 976                         goto instr_done;
 977
 978                 case 339:       /* mfspr */
 979                         spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
 980                         switch (spr) {
 981                         case SPRN_XER:  /* mfxer */
 982                                 regs->gpr[rd] = regs->xer;
 983                                 regs->gpr[rd] &= 0xffffffffUL;
 984                                 goto instr_done;
 985                         case SPRN_LR:   /* mflr */
 986                                 regs->gpr[rd] = regs->link;
 987                                 goto instr_done;
 988                         case SPRN_CTR:  /* mfctr */
 989                                 regs->gpr[rd] = regs->ctr;
 990                                 goto instr_done;
 991                         default:
 992                                 op->type = MFSPR;
 993                                 op->reg = rd;
 994                                 op->spr = spr;
 995                                 return 0;
 996                         }
 997                         break;
 998
 999                 case 467:       /* mtspr */
1000                         spr = ((instr >> 16) & 0x1f) | ((instr >> 6) & 0x3e0);
1001                         switch (spr) {
1002                         case SPRN_XER:  /* mtxer */
1003                                 regs->xer = (regs->gpr[rd] & 0xffffffffUL);
1004                                 goto instr_done;
1005                         case SPRN_LR:   /* mtlr */
1006                                 regs->link = regs->gpr[rd];
1007                                 goto instr_done;
1008                         case SPRN_CTR:  /* mtctr */
1009                                 regs->ctr = regs->gpr[rd];
1010                                 goto instr_done;
1011                         default:
1012                                 op->type = MTSPR;
1013                                 op->val = regs->gpr[rd];
1014                                 op->spr = spr;
1015                                 return 0;
1016                         }
1017                         break;
1018
1019 /*
1020  * Compare instructions
1021  */
1022                 case 0: /* cmp */
1023                         val = regs->gpr[ra];
1024                         val2 = regs->gpr[rb];
1025 #ifdef __powerpc64__
1026                         if ((rd & 1) == 0) {
1027                                 /* word (32-bit) compare */
1028                                 val = (int) val;
1029                                 val2 = (int) val2;
1030                         }
1031 #endif
1032                         do_cmp_signed(regs, val, val2, rd >> 2);
1033                         goto instr_done;
1034
1035                 case 32:        /* cmpl */
1036                         val = regs->gpr[ra];
1037                         val2 = regs->gpr[rb];
1038 #ifdef __powerpc64__
1039                         if ((rd & 1) == 0) {
1040                                 /* word (32-bit) compare */
1041                                 val = (unsigned int) val;
1042                                 val2 = (unsigned int) val2;
1043                         }
1044 #endif
1045                         do_cmp_unsigned(regs, val, val2, rd >> 2);
1046                         goto instr_done;
1047
1048 /*
1049  * Arithmetic instructions
1050  */
1051                 case 8: /* subfc */
1052                         add_with_carry(regs, rd, ~regs->gpr[ra],
1053                                        regs->gpr[rb], 1);
1054                         goto arith_done;
1055 #ifdef __powerpc64__
1056                 case 9: /* mulhdu */
1057                         asm("mulhdu %0,%1,%2" : "=r" (regs->gpr[rd]) :
1058                             "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1059                         goto arith_done;
1060 #endif
1061                 case 10:        /* addc */
1062                         add_with_carry(regs, rd, regs->gpr[ra],
1063                                        regs->gpr[rb], 0);
1064                         goto arith_done;
1065
1066                 case 11:        /* mulhwu */
1067                         asm("mulhwu %0,%1,%2" : "=r" (regs->gpr[rd]) :
1068                             "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1069                         goto arith_done;
1070
1071                 case 40:        /* subf */
1072                         regs->gpr[rd] = regs->gpr[rb] - regs->gpr[ra];
1073                         goto arith_done;
1074 #ifdef __powerpc64__
1075                 case 73:        /* mulhd */
1076                         asm("mulhd %0,%1,%2" : "=r" (regs->gpr[rd]) :
1077                             "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1078                         goto arith_done;
1079 #endif
1080                 case 75:        /* mulhw */
1081                         asm("mulhw %0,%1,%2" : "=r" (regs->gpr[rd]) :
1082                             "r" (regs->gpr[ra]), "r" (regs->gpr[rb]));
1083                         goto arith_done;
1084
1085                 case 104:       /* neg */
1086                         regs->gpr[rd] = -regs->gpr[ra];
1087                         goto arith_done;
1088
1089                 case 136:       /* subfe */
1090                         add_with_carry(regs, rd, ~regs->gpr[ra], regs->gpr[rb],
1091                                        regs->xer & XER_CA);
1092                         goto arith_done;
1093
1094                 case 138:       /* adde */
1095                         add_with_carry(regs, rd, regs->gpr[ra], regs->gpr[rb],
1096                                        regs->xer & XER_CA);
1097                         goto arith_done;
1098
1099                 case 200:       /* subfze */
1100                         add_with_carry(regs, rd, ~regs->gpr[ra], 0L,
1101                                        regs->xer & XER_CA);
1102                         goto arith_done;
1103
1104                 case 202:       /* addze */
1105                         add_with_carry(regs, rd, regs->gpr[ra], 0L,
1106                                        regs->xer & XER_CA);
1107                         goto arith_done;
1108
1109                 case 232:       /* subfme */
1110                         add_with_carry(regs, rd, ~regs->gpr[ra], -1L,
1111                                        regs->xer & XER_CA);
1112                         goto arith_done;
1113 #ifdef __powerpc64__
1114                 case 233:       /* mulld */
1115                         regs->gpr[rd] = regs->gpr[ra] * regs->gpr[rb];
1116                         goto arith_done;
1117 #endif
1118                 case 234:       /* addme */
1119                         add_with_carry(regs, rd, regs->gpr[ra], -1L,
1120                                        regs->xer & XER_CA);
1121                         goto arith_done;
1122
1123                 case 235:       /* mullw */
1124                         regs->gpr[rd] = (unsigned int) regs->gpr[ra] *
1125                                 (unsigned int) regs->gpr[rb];
1126                         goto arith_done;
1127
1128                 case 266:       /* add */
1129                         regs->gpr[rd] = regs->gpr[ra] + regs->gpr[rb];
1130                         goto arith_done;
1131 #ifdef __powerpc64__
1132                 case 457:       /* divdu */
1133                         regs->gpr[rd] = regs->gpr[ra] / regs->gpr[rb];
1134                         goto arith_done;
1135 #endif
1136                 case 459:       /* divwu */
1137                         regs->gpr[rd] = (unsigned int) regs->gpr[ra] /
1138                                 (unsigned int) regs->gpr[rb];
1139                         goto arith_done;
1140 #ifdef __powerpc64__
1141                 case 489:       /* divd */
1142                         regs->gpr[rd] = (long int) regs->gpr[ra] /
1143                                 (long int) regs->gpr[rb];
1144                         goto arith_done;
1145 #endif
1146                 case 491:       /* divw */
1147                         regs->gpr[rd] = (int) regs->gpr[ra] /
1148                                 (int) regs->gpr[rb];
1149                         goto arith_done;
1150
1151
1152 /*
1153  * Logical instructions
1154  */
1155                 case 26:        /* cntlzw */
1156                         asm("cntlzw %0,%1" : "=r" (regs->gpr[ra]) :
1157                             "r" (regs->gpr[rd]));
1158                         goto logical_done;
1159 #ifdef __powerpc64__
1160                 case 58:        /* cntlzd */
1161                         asm("cntlzd %0,%1" : "=r" (regs->gpr[ra]) :
1162                             "r" (regs->gpr[rd]));
1163                         goto logical_done;
1164 #endif
1165                 case 28:        /* and */
1166                         regs->gpr[ra] = regs->gpr[rd] & regs->gpr[rb];
1167                         goto logical_done;
1168
1169                 case 60:        /* andc */
1170                         regs->gpr[ra] = regs->gpr[rd] & ~regs->gpr[rb];
1171                         goto logical_done;
1172
1173                 case 124:       /* nor */
1174                         regs->gpr[ra] = ~(regs->gpr[rd] | regs->gpr[rb]);
1175                         goto logical_done;
1176
1177                 case 284:       /* xor */
1178                         regs->gpr[ra] = ~(regs->gpr[rd] ^ regs->gpr[rb]);
1179                         goto logical_done;
1180
1181                 case 316:       /* xor */
1182                         regs->gpr[ra] = regs->gpr[rd] ^ regs->gpr[rb];
1183                         goto logical_done;
1184
1185                 case 412:       /* orc */
1186                         regs->gpr[ra] = regs->gpr[rd] | ~regs->gpr[rb];
1187                         goto logical_done;
1188
1189                 case 444:       /* or */
1190                         regs->gpr[ra] = regs->gpr[rd] | regs->gpr[rb];
1191                         goto logical_done;
1192
1193                 case 476:       /* nand */
1194                         regs->gpr[ra] = ~(regs->gpr[rd] & regs->gpr[rb]);
1195                         goto logical_done;
1196
1197                 case 922:       /* extsh */
1198                         regs->gpr[ra] = (signed short) regs->gpr[rd];
1199                         goto logical_done;
1200
1201                 case 954:       /* extsb */
1202                         regs->gpr[ra] = (signed char) regs->gpr[rd];
1203                         goto logical_done;
1204 #ifdef __powerpc64__
1205                 case 986:       /* extsw */
1206                         regs->gpr[ra] = (signed int) regs->gpr[rd];
1207                         goto logical_done;
1208 #endif
1209
1210 /*
1211  * Shift instructions
1212  */
1213                 case 24:        /* slw */
1214                         sh = regs->gpr[rb] & 0x3f;
1215                         if (sh < 32)
1216                                 regs->gpr[ra] = (regs->gpr[rd] << sh) & 0xffffffffUL;
1217                         else
1218                                 regs->gpr[ra] = 0;
1219                         goto logical_done;
1220
1221                 case 536:       /* srw */
1222                         sh = regs->gpr[rb] & 0x3f;
1223                         if (sh < 32)
1224                                 regs->gpr[ra] = (regs->gpr[rd] & 0xffffffffUL) >> sh;
1225                         else
1226                                 regs->gpr[ra] = 0;
1227                         goto logical_done;
1228
1229                 case 792:       /* sraw */
1230                         sh = regs->gpr[rb] & 0x3f;
1231                         ival = (signed int) regs->gpr[rd];
1232                         regs->gpr[ra] = ival >> (sh < 32 ? sh : 31);
1233                         if (ival < 0 && (sh >= 32 || (ival & ((1ul << sh) - 1)) != 0))
1234                                 regs->xer |= XER_CA;
1235                         else
1236                                 regs->xer &= ~XER_CA;
1237                         goto logical_done;
1238
1239                 case 824:       /* srawi */
1240                         sh = rb;
1241                         ival = (signed int) regs->gpr[rd];
1242                         regs->gpr[ra] = ival >> sh;
1243                         if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
1244                                 regs->xer |= XER_CA;
1245                         else
1246                                 regs->xer &= ~XER_CA;
1247                         goto logical_done;
1248
1249 #ifdef __powerpc64__
1250                 case 27:        /* sld */
1251                         sh = regs->gpr[rb] & 0x7f;
1252                         if (sh < 64)
1253                                 regs->gpr[ra] = regs->gpr[rd] << sh;
1254                         else
1255                                 regs->gpr[ra] = 0;
1256                         goto logical_done;
1257
1258                 case 539:       /* srd */
1259                         sh = regs->gpr[rb] & 0x7f;
1260                         if (sh < 64)
1261                                 regs->gpr[ra] = regs->gpr[rd] >> sh;
1262                         else
1263                                 regs->gpr[ra] = 0;
1264                         goto logical_done;
1265
1266                 case 794:       /* srad */
1267                         sh = regs->gpr[rb] & 0x7f;
1268                         ival = (signed long int) regs->gpr[rd];
1269                         regs->gpr[ra] = ival >> (sh < 64 ? sh : 63);
1270                         if (ival < 0 && (sh >= 64 || (ival & ((1ul << sh) - 1)) != 0))
1271                                 regs->xer |= XER_CA;
1272                         else
1273                                 regs->xer &= ~XER_CA;
1274                         goto logical_done;
1275
1276                 case 826:       /* sradi with sh_5 = 0 */
1277                 case 827:       /* sradi with sh_5 = 1 */
1278                         sh = rb | ((instr & 2) << 4);
1279                         ival = (signed long int) regs->gpr[rd];
1280                         regs->gpr[ra] = ival >> sh;
1281                         if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0)
1282                                 regs->xer |= XER_CA;
1283                         else
1284                                 regs->xer &= ~XER_CA;
1285                         goto logical_done;
1286 #endif /* __powerpc64__ */
1287
1288 /*
1289  * Cache instructions
1290  */
1291                 case 54:        /* dcbst */
1292                         op->type = MKOP(CACHEOP, DCBST, 0);
1293                         op->ea = xform_ea(instr, regs);
1294                         return 0;
1295
1296                 case 86:        /* dcbf */
1297                         op->type = MKOP(CACHEOP, DCBF, 0);
1298                         op->ea = xform_ea(instr, regs);
1299                         return 0;
1300
1301                 case 246:       /* dcbtst */
1302                         op->type = MKOP(CACHEOP, DCBTST, 0);
1303                         op->ea = xform_ea(instr, regs);
1304                         op->reg = rd;
1305                         return 0;
1306
1307                 case 278:       /* dcbt */
1308                         op->type = MKOP(CACHEOP, DCBTST, 0);
1309                         op->ea = xform_ea(instr, regs);
1310                         op->reg = rd;
1311                         return 0;
1312
1313                 case 982:       /* icbi */
1314                         op->type = MKOP(CACHEOP, ICBI, 0);
1315                         op->ea = xform_ea(instr, regs);
1316                         return 0;
1317                 }
1318                 break;
1319         }
1320
1321         /*
1322          * Loads and stores.
1323          */
1324         op->type = UNKNOWN;
1325         op->update_reg = ra;
1326         op->reg = rd;
1327         op->val = regs->gpr[rd];
1328         u = (instr >> 20) & UPDATE;
1329
1330         switch (opcode) {
1331         case 31:
1332                 u = instr & UPDATE;
1333                 op->ea = xform_ea(instr, regs);
1334                 switch ((instr >> 1) & 0x3ff) {
1335                 case 20:        /* lwarx */
1336                         op->type = MKOP(LARX, 0, 4);
1337                         break;
1338
1339                 case 150:       /* stwcx. */
1340                         op->type = MKOP(STCX, 0, 4);
1341                         break;
1342
1343 #ifdef __powerpc64__
1344                 case 84:        /* ldarx */
1345                         op->type = MKOP(LARX, 0, 8);
1346                         break;
1347
1348                 case 214:       /* stdcx. */
1349                         op->type = MKOP(STCX, 0, 8);
1350                         break;
1351
1352                 case 21:        /* ldx */
1353                 case 53:        /* ldux */
1354                         op->type = MKOP(LOAD, u, 8);
1355                         break;
1356 #endif
1357
1358                 case 23:        /* lwzx */
1359                 case 55:        /* lwzux */
1360                         op->type = MKOP(LOAD, u, 4);
1361                         break;
1362
1363                 case 87:        /* lbzx */
1364                 case 119:       /* lbzux */
1365                         op->type = MKOP(LOAD, u, 1);
1366                         break;
1367
1368 #ifdef CONFIG_ALTIVEC
1369                 case 103:       /* lvx */
1370                 case 359:       /* lvxl */
1371                         if (!(regs->msr & MSR_VEC))
1372                                 goto vecunavail;
1373                         op->type = MKOP(LOAD_VMX, 0, 16);
1374                         break;
1375
1376                 case 231:       /* stvx */
1377                 case 487:       /* stvxl */
1378                         if (!(regs->msr & MSR_VEC))
1379                                 goto vecunavail;
1380                         op->type = MKOP(STORE_VMX, 0, 16);
1381                         break;
1382 #endif /* CONFIG_ALTIVEC */
1383
1384 #ifdef __powerpc64__
1385                 case 149:       /* stdx */
1386                 case 181:       /* stdux */
1387                         op->type = MKOP(STORE, u, 8);
1388                         break;
1389 #endif
1390
1391                 case 151:       /* stwx */
1392                 case 183:       /* stwux */
1393                         op->type = MKOP(STORE, u, 4);
1394                         break;
1395
1396                 case 215:       /* stbx */
1397                 case 247:       /* stbux */
1398                         op->type = MKOP(STORE, u, 1);
1399                         break;
1400
1401                 case 279:       /* lhzx */
1402                 case 311:       /* lhzux */
1403                         op->type = MKOP(LOAD, u, 2);
1404                         break;
1405
1406 #ifdef __powerpc64__
1407                 case 341:       /* lwax */
1408                 case 373:       /* lwaux */
1409                         op->type = MKOP(LOAD, SIGNEXT | u, 4);
1410                         break;
1411 #endif
1412
1413                 case 343:       /* lhax */
1414                 case 375:       /* lhaux */
1415                         op->type = MKOP(LOAD, SIGNEXT | u, 2);
1416                         break;
1417
1418                 case 407:       /* sthx */
1419                 case 439:       /* sthux */
1420                         op->type = MKOP(STORE, u, 2);
1421                         break;
1422
1423 #ifdef __powerpc64__
1424                 case 532:       /* ldbrx */
1425                         op->type = MKOP(LOAD, BYTEREV, 8);
1426                         break;
1427
1428 #endif
1429                 case 533:       /* lswx */
1430                         op->type = MKOP(LOAD_MULTI, 0, regs->xer & 0x7f);
1431                         break;
1432
1433                 case 534:       /* lwbrx */
1434                         op->type = MKOP(LOAD, BYTEREV, 4);
1435                         break;
1436
1437                 case 597:       /* lswi */
1438                         if (rb == 0)
1439                                 rb = 32;        /* # bytes to load */
1440                         op->type = MKOP(LOAD_MULTI, 0, rb);
1441                         op->ea = 0;
1442                         if (ra)
1443                                 op->ea = truncate_if_32bit(regs->msr,
1444                                                            regs->gpr[ra]);
1445                         break;
1446
1447 #ifdef CONFIG_PPC_FPU
1448                 case 535:       /* lfsx */
1449                 case 567:       /* lfsux */
1450                         if (!(regs->msr & MSR_FP))
1451                                 goto fpunavail;
1452                         op->type = MKOP(LOAD_FP, u, 4);
1453                         break;
1454
1455                 case 599:       /* lfdx */
1456                 case 631:       /* lfdux */
1457                         if (!(regs->msr & MSR_FP))
1458                                 goto fpunavail;
1459                         op->type = MKOP(LOAD_FP, u, 8);
1460                         break;
1461
1462                 case 663:       /* stfsx */
1463                 case 695:       /* stfsux */
1464                         if (!(regs->msr & MSR_FP))
1465                                 goto fpunavail;
1466                         op->type = MKOP(STORE_FP, u, 4);
1467                         break;
1468
1469                 case 727:       /* stfdx */
1470                 case 759:       /* stfdux */
1471                         if (!(regs->msr & MSR_FP))
1472                                 goto fpunavail;
1473                         op->type = MKOP(STORE_FP, u, 8);
1474                         break;
1475 #endif
1476
1477 #ifdef __powerpc64__
1478                 case 660:       /* stdbrx */
1479                         op->type = MKOP(STORE, BYTEREV, 8);
1480                         op->val = byterev_8(regs->gpr[rd]);
1481                         break;
1482
1483 #endif
1484                 case 661:       /* stswx */
1485                         op->type = MKOP(STORE_MULTI, 0, regs->xer & 0x7f);
1486                         break;
1487
1488                 case 662:       /* stwbrx */
1489                         op->type = MKOP(STORE, BYTEREV, 4);
1490                         op->val = byterev_4(regs->gpr[rd]);
1491                         break;
1492
1493                 case 725:
1494                         if (rb == 0)
1495                                 rb = 32;        /* # bytes to store */
1496                         op->type = MKOP(STORE_MULTI, 0, rb);
1497                         op->ea = 0;
1498                         if (ra)
1499                                 op->ea = truncate_if_32bit(regs->msr,
1500                                                            regs->gpr[ra]);
1501                         break;
1502
1503                 case 790:       /* lhbrx */
1504                         op->type = MKOP(LOAD, BYTEREV, 2);
1505                         break;
1506
1507                 case 918:       /* sthbrx */
1508                         op->type = MKOP(STORE, BYTEREV, 2);
1509                         op->val = byterev_2(regs->gpr[rd]);
1510                         break;
1511
1512 #ifdef CONFIG_VSX
1513                 case 844:       /* lxvd2x */
1514                 case 876:       /* lxvd2ux */
1515                         if (!(regs->msr & MSR_VSX))
1516                                 goto vsxunavail;
1517                         op->reg = rd | ((instr & 1) << 5);
1518                         op->type = MKOP(LOAD_VSX, u, 16);
1519                         break;
1520
1521                 case 972:       /* stxvd2x */
1522                 case 1004:      /* stxvd2ux */
1523                         if (!(regs->msr & MSR_VSX))
1524                                 goto vsxunavail;
1525                         op->reg = rd | ((instr & 1) << 5);
1526                         op->type = MKOP(STORE_VSX, u, 16);
1527                         break;
1528
1529 #endif /* CONFIG_VSX */
1530                 }
1531                 break;
1532
1533         case 32:        /* lwz */
1534         case 33:        /* lwzu */
1535                 op->type = MKOP(LOAD, u, 4);
1536                 op->ea = dform_ea(instr, regs);
1537                 break;
1538
1539         case 34:        /* lbz */
1540         case 35:        /* lbzu */
1541                 op->type = MKOP(LOAD, u, 1);
1542                 op->ea = dform_ea(instr, regs);
1543                 break;
1544
1545         case 36:        /* stw */
1546         case 37:        /* stwu */
1547                 op->type = MKOP(STORE, u, 4);
1548                 op->ea = dform_ea(instr, regs);
1549                 break;
1550
1551         case 38:        /* stb */
1552         case 39:        /* stbu */
1553                 op->type = MKOP(STORE, u, 1);
1554                 op->ea = dform_ea(instr, regs);
1555                 break;
1556
1557         case 40:        /* lhz */
1558         case 41:        /* lhzu */
1559                 op->type = MKOP(LOAD, u, 2);
1560                 op->ea = dform_ea(instr, regs);
1561                 break;
1562
1563         case 42:        /* lha */
1564         case 43:        /* lhau */
1565                 op->type = MKOP(LOAD, SIGNEXT | u, 2);
1566                 op->ea = dform_ea(instr, regs);
1567                 break;
1568
1569         case 44:        /* sth */
1570         case 45:        /* sthu */
1571                 op->type = MKOP(STORE, u, 2);
1572                 op->ea = dform_ea(instr, regs);
1573                 break;
1574
1575         case 46:        /* lmw */
1576                 if (ra >= rd)
1577                         break;          /* invalid form, ra in range to load */
1578                 op->type = MKOP(LOAD_MULTI, 0, 4 * (32 - rd));
1579                 op->ea = dform_ea(instr, regs);
1580                 break;
1581
1582         case 47:        /* stmw */
1583                 op->type = MKOP(STORE_MULTI, 0, 4 * (32 - rd));
1584                 op->ea = dform_ea(instr, regs);
1585                 break;
1586
1587 #ifdef CONFIG_PPC_FPU
1588         case 48:        /* lfs */
1589         case 49:        /* lfsu */
1590                 if (!(regs->msr & MSR_FP))
1591                         goto fpunavail;
1592                 op->type = MKOP(LOAD_FP, u, 4);
1593                 op->ea = dform_ea(instr, regs);
1594                 break;
1595
1596         case 50:        /* lfd */
1597         case 51:        /* lfdu */
1598                 if (!(regs->msr & MSR_FP))
1599                         goto fpunavail;
1600                 op->type = MKOP(LOAD_FP, u, 8);
1601                 op->ea = dform_ea(instr, regs);
1602                 break;
1603
1604         case 52:        /* stfs */
1605         case 53:        /* stfsu */
1606                 if (!(regs->msr & MSR_FP))
1607                         goto fpunavail;
1608                 op->type = MKOP(STORE_FP, u, 4);
1609                 op->ea = dform_ea(instr, regs);
1610                 break;
1611
1612         case 54:        /* stfd */
1613         case 55:        /* stfdu */
1614                 if (!(regs->msr & MSR_FP))
1615                         goto fpunavail;
1616                 op->type = MKOP(STORE_FP, u, 8);
1617                 op->ea = dform_ea(instr, regs);
1618                 break;
1619 #endif
1620
1621 #ifdef __powerpc64__
1622         case 58:        /* ld[u], lwa */
1623                 op->ea = dsform_ea(instr, regs);
1624                 switch (instr & 3) {
1625                 case 0:         /* ld */
1626                         op->type = MKOP(LOAD, 0, 8);
1627                         break;
1628                 case 1:         /* ldu */
1629                         op->type = MKOP(LOAD, UPDATE, 8);
1630                         break;
1631                 case 2:         /* lwa */
1632                         op->type = MKOP(LOAD, SIGNEXT, 4);
1633                         break;
1634                 }
1635                 break;
1636
1637         case 62:        /* std[u] */
1638                 op->ea = dsform_ea(instr, regs);
1639                 switch (instr & 3) {
1640                 case 0:         /* std */
1641                         op->type = MKOP(STORE, 0, 8);
1642                         break;
1643                 case 1:         /* stdu */
1644                         op->type = MKOP(STORE, UPDATE, 8);
1645                         break;
1646                 }
1647                 break;
1648 #endif /* __powerpc64__ */
1649
1650         }
1651         return 0;
1652
1653  logical_done:
1654         if (instr & 1)
1655                 set_cr0(regs, ra);
1656         goto instr_done;
1657
1658  arith_done:
1659         if (instr & 1)
1660                 set_cr0(regs, rd);
1661
1662  instr_done:
1663         regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
1664         return 1;
1665
1666  priv:
1667         op->type = INTERRUPT | 0x700;
1668         op->val = SRR1_PROGPRIV;
1669         return 0;
1670
1671  trap:
1672         op->type = INTERRUPT | 0x700;
1673         op->val = SRR1_PROGTRAP;
1674         return 0;
1675
1676 #ifdef CONFIG_PPC_FPU
1677  fpunavail:
1678         op->type = INTERRUPT | 0x800;
1679         return 0;
1680 #endif
1681
1682 #ifdef CONFIG_ALTIVEC
1683  vecunavail:
1684         op->type = INTERRUPT | 0xf20;
1685         return 0;
1686 #endif
1687
1688 #ifdef CONFIG_VSX
1689  vsxunavail:
1690         op->type = INTERRUPT | 0xf40;
1691         return 0;
1692 #endif
1693 }
1694 EXPORT_SYMBOL_GPL(analyse_instr);
1695
1696 /*
1697  * For PPC32 we always use stwu with r1 to change the stack pointer.
1698  * So this emulated store may corrupt the exception frame, now we
1699  * have to provide the exception frame trampoline, which is pushed
1700  * below the kprobed function stack. So we only update gpr[1] but
1701  * don't emulate the real store operation. We will do real store
1702  * operation safely in exception return code by checking this flag.
1703  */
1704 static __kprobes int handle_stack_update(unsigned long ea, struct pt_regs *regs)
1705 {
1706 #ifdef CONFIG_PPC32
1707         /*
1708          * Check if we will touch kernel stack overflow
1709          */
1710         if (ea - STACK_INT_FRAME_SIZE <= current->thread.ksp_limit) {
1711                 printk(KERN_CRIT "Can't kprobe this since kernel stack would overflow.\n");
1712                 return -EINVAL;
1713         }
1714 #endif /* CONFIG_PPC32 */
1715         /*
1716          * Check if we already set since that means we'll
1717          * lose the previous value.
1718          */
1719         WARN_ON(test_thread_flag(TIF_EMULATE_STACK_STORE));
1720         set_thread_flag(TIF_EMULATE_STACK_STORE);
1721         return 0;
1722 }
1723
1724 static __kprobes void do_signext(unsigned long *valp, int size)
1725 {
1726         switch (size) {
1727         case 2:
1728                 *valp = (signed short) *valp;
1729                 break;
1730         case 4:
1731                 *valp = (signed int) *valp;
1732                 break;
1733         }
1734 }
1735
1736 static __kprobes void do_byterev(unsigned long *valp, int size)
1737 {
1738         switch (size) {
1739         case 2:
1740                 *valp = byterev_2(*valp);
1741                 break;
1742         case 4:
1743                 *valp = byterev_4(*valp);
1744                 break;
1745 #ifdef __powerpc64__
1746         case 8:
1747                 *valp = byterev_8(*valp);
1748                 break;
1749 #endif
1750         }
1751 }
1752
1753 /*
1754  * Emulate instructions that cause a transfer of control,
1755  * loads and stores, and a few other instructions.
1756  * Returns 1 if the step was emulated, 0 if not,
1757  * or -1 if the instruction is one that should not be stepped,
1758  * such as an rfid, or a mtmsrd that would clear MSR_RI.
1759  */
1760 int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr)
1761 {
1762         struct instruction_op op;
1763         int r, err, size;
1764         unsigned long val;
1765         unsigned int cr;
1766         int i, rd, nb;
1767
1768         r = analyse_instr(&op, regs, instr);
1769         if (r != 0)
1770                 return r;
1771
1772         err = 0;
1773         size = GETSIZE(op.type);
1774         switch (op.type & INSTR_TYPE_MASK) {
1775         case CACHEOP:
1776                 if (!address_ok(regs, op.ea, 8))
1777                         return 0;
1778                 switch (op.type & CACHEOP_MASK) {
1779                 case DCBST:
1780                         __cacheop_user_asmx(op.ea, err, "dcbst");
1781                         break;
1782                 case DCBF:
1783                         __cacheop_user_asmx(op.ea, err, "dcbf");
1784                         break;
1785                 case DCBTST:
1786                         if (op.reg == 0)
1787                                 prefetchw((void *) op.ea);
1788                         break;
1789                 case DCBT:
1790                         if (op.reg == 0)
1791                                 prefetch((void *) op.ea);
1792                         break;
1793                 case ICBI:
1794                         __cacheop_user_asmx(op.ea, err, "icbi");
1795                         break;
1796                 }
1797                 if (err)
1798                         return 0;
1799                 goto instr_done;
1800
1801         case LARX:
1802                 if (op.ea & (size - 1))
1803                         break;          /* can't handle misaligned */
1804                 if (!address_ok(regs, op.ea, size))
1805                         return 0;
1806                 err = 0;
1807                 switch (size) {
1808                 case 4:
1809                         __get_user_asmx(val, op.ea, err, "lwarx");
1810                         break;
1811 #ifdef __powerpc64__
1812                 case 8:
1813                         __get_user_asmx(val, op.ea, err, "ldarx");
1814                         break;
1815 #endif
1816                 default:
1817                         return 0;
1818                 }
1819                 if (!err)
1820                         regs->gpr[op.reg] = val;
1821                 goto ldst_done;
1822
1823         case STCX:
1824                 if (op.ea & (size - 1))
1825                         break;          /* can't handle misaligned */
1826                 if (!address_ok(regs, op.ea, size))
1827                         return 0;
1828                 err = 0;
1829                 switch (size) {
1830                 case 4:
1831                         __put_user_asmx(op.val, op.ea, err, "stwcx.", cr);
1832                         break;
1833 #ifdef __powerpc64__
1834                 case 8:
1835                         __put_user_asmx(op.val, op.ea, err, "stdcx.", cr);
1836                         break;
1837 #endif
1838                 default:
1839                         return 0;
1840                 }
1841                 if (!err)
1842                         regs->ccr = (regs->ccr & 0x0fffffff) |
1843                                 (cr & 0xe0000000) |
1844                                 ((regs->xer >> 3) & 0x10000000);
1845                 goto ldst_done;
1846
1847         case LOAD:
1848                 err = read_mem(&regs->gpr[op.reg], op.ea, size, regs);
1849                 if (!err) {
1850                         if (op.type & SIGNEXT)
1851                                 do_signext(&regs->gpr[op.reg], size);
1852                         if (op.type & BYTEREV)
1853                                 do_byterev(&regs->gpr[op.reg], size);
1854                 }
1855                 goto ldst_done;
1856
1857 #ifdef CONFIG_PPC_FPU
1858         case LOAD_FP:
1859                 if (size == 4)
1860                         err = do_fp_load(op.reg, do_lfs, op.ea, size, regs);
1861                 else
1862                         err = do_fp_load(op.reg, do_lfd, op.ea, size, regs);
1863                 goto ldst_done;
1864 #endif
1865 #ifdef CONFIG_ALTIVEC
1866         case LOAD_VMX:
1867                 err = do_vec_load(op.reg, do_lvx, op.ea & ~0xfUL, regs);
1868                 goto ldst_done;
1869 #endif
1870 #ifdef CONFIG_VSX
1871         case LOAD_VSX:
1872                 err = do_vsx_load(op.reg, do_lxvd2x, op.ea, regs);
1873                 goto ldst_done;
1874 #endif
1875         case LOAD_MULTI:
1876                 if (regs->msr & MSR_LE)
1877                         return 0;
1878                 rd = op.reg;
1879                 for (i = 0; i < size; i += 4) {
1880                         nb = size - i;
1881                         if (nb > 4)
1882                                 nb = 4;
1883                         err = read_mem(&regs->gpr[rd], op.ea, nb, regs);
1884                         if (err)
1885                                 return 0;
1886                         if (nb < 4)     /* left-justify last bytes */
1887                                 regs->gpr[rd] <<= 32 - 8 * nb;
1888                         op.ea += 4;
1889                         ++rd;
1890                 }
1891                 goto instr_done;
1892
1893         case STORE:
1894                 if ((op.type & UPDATE) && size == sizeof(long) &&
1895                     op.reg == 1 && op.update_reg == 1 &&
1896                     !(regs->msr & MSR_PR) &&
1897                     op.ea >= regs->gpr[1] - STACK_INT_FRAME_SIZE) {
1898                         err = handle_stack_update(op.ea, regs);
1899                         goto ldst_done;
1900                 }
1901                 err = write_mem(op.val, op.ea, size, regs);
1902                 goto ldst_done;
1903
1904 #ifdef CONFIG_PPC_FPU
1905         case STORE_FP:
1906                 if (size == 4)
1907                         err = do_fp_store(op.reg, do_stfs, op.ea, size, regs);
1908                 else
1909                         err = do_fp_store(op.reg, do_stfd, op.ea, size, regs);
1910                 goto ldst_done;
1911 #endif
1912 #ifdef CONFIG_ALTIVEC
1913         case STORE_VMX:
1914                 err = do_vec_store(op.reg, do_stvx, op.ea & ~0xfUL, regs);
1915                 goto ldst_done;
1916 #endif
1917 #ifdef CONFIG_VSX
1918         case STORE_VSX:
1919                 err = do_vsx_store(op.reg, do_stxvd2x, op.ea, regs);
1920                 goto ldst_done;
1921 #endif
1922         case STORE_MULTI:
1923                 if (regs->msr & MSR_LE)
1924                         return 0;
1925                 rd = op.reg;
1926                 for (i = 0; i < size; i += 4) {
1927                         val = regs->gpr[rd];
1928                         nb = size - i;
1929                         if (nb > 4)
1930                                 nb = 4;
1931                         else
1932                                 val >>= 32 - 8 * nb;
1933                         err = write_mem(val, op.ea, nb, regs);
1934                         if (err)
1935                                 return 0;
1936                         op.ea += 4;
1937                         ++rd;
1938                 }
1939                 goto instr_done;
1940
1941         case MFMSR:
1942                 regs->gpr[op.reg] = regs->msr & MSR_MASK;
1943                 goto instr_done;
1944
1945         case MTMSR:
1946                 val = regs->gpr[op.reg];
1947                 if ((val & MSR_RI) == 0)
1948                         /* can't step mtmsr[d] that would clear MSR_RI */
1949                         return -1;
1950                 /* here op.val is the mask of bits to change */
1951                 regs->msr = (regs->msr & ~op.val) | (val & op.val);
1952                 goto instr_done;
1953
1954 #ifdef CONFIG_PPC64
1955         case SYSCALL:   /* sc */
1956                 /*
1957                  * N.B. this uses knowledge about how the syscall
1958                  * entry code works.  If that is changed, this will
1959                  * need to be changed also.
1960                  */
1961                 if (regs->gpr[0] == 0x1ebe &&
1962                     cpu_has_feature(CPU_FTR_REAL_LE)) {
1963                         regs->msr ^= MSR_LE;
1964                         goto instr_done;
1965                 }
1966                 regs->gpr[9] = regs->gpr[13];
1967                 regs->gpr[10] = MSR_KERNEL;
1968                 regs->gpr[11] = regs->nip + 4;
1969                 regs->gpr[12] = regs->msr & MSR_MASK;
1970                 regs->gpr[13] = (unsigned long) get_paca();
1971                 regs->nip = (unsigned long) &system_call_common;
1972                 regs->msr = MSR_KERNEL;
1973                 return 1;
1974
1975         case RFI:
1976                 return -1;
1977 #endif
1978         }
1979         return 0;
1980
1981  ldst_done:
1982         if (err)
1983                 return 0;
1984         if (op.type & UPDATE)
1985                 regs->gpr[op.update_reg] = op.ea;
1986
1987  instr_done:
1988         regs->nip = truncate_if_32bit(regs->msr, regs->nip + 4);
1989         return 1;
1990 }