lib/decompress_unlzma.c

   1 /* Lzma decompressor for Linux kernel. Shamelessly snarfed
   2  *from busybox 1.1.1
   3  *
   4  *Linux kernel adaptation
   5  *Copyright (C) 2006  Alain < alain@knaff.lu >
   6  *
   7  *Based on small lzma deflate implementation/Small range coder
   8  *implementation for lzma.
   9  *Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
  10  *
  11  *Based on LzmaDecode.c from the LZMA SDK 4.22 (https://www.7-zip.org/)
  12  *Copyright (C) 1999-2005  Igor Pavlov
  13  *
  14  *Copyrights of the parts, see headers below.
  15  *
  16  *
  17  *This program is free software; you can redistribute it and/or
  18  *modify it under the terms of the GNU Lesser General Public
  19  *License as published by the Free Software Foundation; either
  20  *version 2.1 of the License, or (at your option) any later version.
  21  *
  22  *This program is distributed in the hope that it will be useful,
  23  *but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  *Lesser General Public License for more details.
  26  *
  27  *You should have received a copy of the GNU Lesser General Public
  28  *License along with this library; if not, write to the Free Software
  29  *Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  30  */
  31
  32 #ifdef STATIC
  33 #define PREBOOT
  34 #else
  35 #include <linux/decompress/unlzma.h>
  36 #endif /* STATIC */
  37
  38 #include <linux/decompress/mm.h>
  39
  40 #ifndef MIN
  41 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
  42 #endif
  43
  44 static long long INIT read_int(unsigned char *ptr, int size)
  45 {
  46         int i;
  47         long long ret = 0;
  48
  49         for (i = 0; i < size; i++)
  50                 ret = (ret << 8) | ptr[size-i-1];
  51         return ret;
  52 }
  53
  54 #define ENDIAN_CONVERT(x) \
  55   x = (typeof(x))read_int((unsigned char *)&x, sizeof(x))
  56
  57
  58 /* Small range coder implementation for lzma.
  59  *Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
  60  *
  61  *Based on LzmaDecode.c from the LZMA SDK 4.22 (https://www.7-zip.org/)
  62  *Copyright (c) 1999-2005  Igor Pavlov
  63  */
  64
  65 #include <linux/compiler.h>
  66
  67 #define LZMA_IOBUF_SIZE 0x10000
  68
  69 struct rc {
  70         long (*fill)(void*, unsigned long);
  71         uint8_t *ptr;
  72         uint8_t *buffer;
  73         uint8_t *buffer_end;
  74         long buffer_size;
  75         uint32_t code;
  76         uint32_t range;
  77         uint32_t bound;
  78         void (*error)(char *);
  79 };
  80
  81
  82 #define RC_TOP_BITS 24
  83 #define RC_MOVE_BITS 5
  84 #define RC_MODEL_TOTAL_BITS 11
  85
  86
  87 static long INIT nofill(void *buffer, unsigned long len)
  88 {
  89         return -1;
  90 }
  91
  92 /* Called twice: once at startup and once in rc_normalize() */
  93 static void INIT rc_read(struct rc *rc)
  94 {
  95         rc->buffer_size = rc->fill((char *)rc->buffer, LZMA_IOBUF_SIZE);
  96         if (rc->buffer_size <= 0)
  97                 rc->error("unexpected EOF");
  98         rc->ptr = rc->buffer;
  99         rc->buffer_end = rc->buffer + rc->buffer_size;
 100 }
 101
 102 /* Called once */
 103 static inline void INIT rc_init(struct rc *rc,
 104                                        long (*fill)(void*, unsigned long),
 105                                        char *buffer, long buffer_size)
 106 {
 107         if (fill)
 108                 rc->fill = fill;
 109         else
 110                 rc->fill = nofill;
 111         rc->buffer = (uint8_t *)buffer;
 112         rc->buffer_size = buffer_size;
 113         rc->buffer_end = rc->buffer + rc->buffer_size;
 114         rc->ptr = rc->buffer;
 115
 116         rc->code = 0;
 117         rc->range = 0xFFFFFFFF;
 118 }
 119
 120 static inline void INIT rc_init_code(struct rc *rc)
 121 {
 122         int i;
 123
 124         for (i = 0; i < 5; i++) {
 125                 if (rc->ptr >= rc->buffer_end)
 126                         rc_read(rc);
 127                 rc->code = (rc->code << 8) | *rc->ptr++;
 128         }
 129 }
 130
 131
 132 /* Called twice, but one callsite is in inline'd rc_is_bit_0_helper() */
 133 static void INIT rc_do_normalize(struct rc *rc)
 134 {
 135         if (rc->ptr >= rc->buffer_end)
 136                 rc_read(rc);
 137         rc->range <<= 8;
 138         rc->code = (rc->code << 8) | *rc->ptr++;
 139 }
 140 static inline void INIT rc_normalize(struct rc *rc)
 141 {
 142         if (rc->range < (1 << RC_TOP_BITS))
 143                 rc_do_normalize(rc);
 144 }
 145
 146 /* Called 9 times */
 147 /* Why rc_is_bit_0_helper exists?
 148  *Because we want to always expose (rc->code < rc->bound) to optimizer
 149  */
 150 static inline uint32_t INIT rc_is_bit_0_helper(struct rc *rc, uint16_t *p)
 151 {
 152         rc_normalize(rc);
 153         rc->bound = *p * (rc->range >> RC_MODEL_TOTAL_BITS);
 154         return rc->bound;
 155 }
 156 static inline int INIT rc_is_bit_0(struct rc *rc, uint16_t *p)
 157 {
 158         uint32_t t = rc_is_bit_0_helper(rc, p);
 159         return rc->code < t;
 160 }
 161
 162 /* Called ~10 times, but very small, thus inlined */
 163 static inline void INIT rc_update_bit_0(struct rc *rc, uint16_t *p)
 164 {
 165         rc->range = rc->bound;
 166         *p += ((1 << RC_MODEL_TOTAL_BITS) - *p) >> RC_MOVE_BITS;
 167 }
 168 static inline void INIT rc_update_bit_1(struct rc *rc, uint16_t *p)
 169 {
 170         rc->range -= rc->bound;
 171         rc->code -= rc->bound;
 172         *p -= *p >> RC_MOVE_BITS;
 173 }
 174
 175 /* Called 4 times in unlzma loop */
 176 static int INIT rc_get_bit(struct rc *rc, uint16_t *p, int *symbol)
 177 {
 178         if (rc_is_bit_0(rc, p)) {
 179                 rc_update_bit_0(rc, p);
 180                 *symbol *= 2;
 181                 return 0;
 182         } else {
 183                 rc_update_bit_1(rc, p);
 184                 *symbol = *symbol * 2 + 1;
 185                 return 1;
 186         }
 187 }
 188
 189 /* Called once */
 190 static inline int INIT rc_direct_bit(struct rc *rc)
 191 {
 192         rc_normalize(rc);
 193         rc->range >>= 1;
 194         if (rc->code >= rc->range) {
 195                 rc->code -= rc->range;
 196                 return 1;
 197         }
 198         return 0;
 199 }
 200
 201 /* Called twice */
 202 static inline void INIT
 203 rc_bit_tree_decode(struct rc *rc, uint16_t *p, int num_levels, int *symbol)
 204 {
 205         int i = num_levels;
 206
 207         *symbol = 1;
 208         while (i--)
 209                 rc_get_bit(rc, p + *symbol, symbol);
 210         *symbol -= 1 << num_levels;
 211 }
 212
 213
 214 /*
 215  * Small lzma deflate implementation.
 216  * Copyright (C) 2006  Aurelien Jacobs < aurel@gnuage.org >
 217  *
 218  * Based on LzmaDecode.c from the LZMA SDK 4.22 (https://www.7-zip.org/)
 219  * Copyright (C) 1999-2005  Igor Pavlov
 220  */
 221
 222
 223 struct lzma_header {
 224         uint8_t pos;
 225         uint32_t dict_size;
 226         uint64_t dst_size;
 227 } __attribute__ ((packed)) ;
 228
 229
 230 #define LZMA_BASE_SIZE 1846
 231 #define LZMA_LIT_SIZE 768
 232
 233 #define LZMA_NUM_POS_BITS_MAX 4
 234
 235 #define LZMA_LEN_NUM_LOW_BITS 3
 236 #define LZMA_LEN_NUM_MID_BITS 3
 237 #define LZMA_LEN_NUM_HIGH_BITS 8
 238
 239 #define LZMA_LEN_CHOICE 0
 240 #define LZMA_LEN_CHOICE_2 (LZMA_LEN_CHOICE + 1)
 241 #define LZMA_LEN_LOW (LZMA_LEN_CHOICE_2 + 1)
 242 #define LZMA_LEN_MID (LZMA_LEN_LOW \
 243                       + (1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_LOW_BITS)))
 244 #define LZMA_LEN_HIGH (LZMA_LEN_MID \
 245                        +(1 << (LZMA_NUM_POS_BITS_MAX + LZMA_LEN_NUM_MID_BITS)))
 246 #define LZMA_NUM_LEN_PROBS (LZMA_LEN_HIGH + (1 << LZMA_LEN_NUM_HIGH_BITS))
 247
 248 #define LZMA_NUM_STATES 12
 249 #define LZMA_NUM_LIT_STATES 7
 250
 251 #define LZMA_START_POS_MODEL_INDEX 4
 252 #define LZMA_END_POS_MODEL_INDEX 14
 253 #define LZMA_NUM_FULL_DISTANCES (1 << (LZMA_END_POS_MODEL_INDEX >> 1))
 254
 255 #define LZMA_NUM_POS_SLOT_BITS 6
 256 #define LZMA_NUM_LEN_TO_POS_STATES 4
 257
 258 #define LZMA_NUM_ALIGN_BITS 4
 259
 260 #define LZMA_MATCH_MIN_LEN 2
 261
 262 #define LZMA_IS_MATCH 0
 263 #define LZMA_IS_REP (LZMA_IS_MATCH + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
 264 #define LZMA_IS_REP_G0 (LZMA_IS_REP + LZMA_NUM_STATES)
 265 #define LZMA_IS_REP_G1 (LZMA_IS_REP_G0 + LZMA_NUM_STATES)
 266 #define LZMA_IS_REP_G2 (LZMA_IS_REP_G1 + LZMA_NUM_STATES)
 267 #define LZMA_IS_REP_0_LONG (LZMA_IS_REP_G2 + LZMA_NUM_STATES)
 268 #define LZMA_POS_SLOT (LZMA_IS_REP_0_LONG \
 269                        + (LZMA_NUM_STATES << LZMA_NUM_POS_BITS_MAX))
 270 #define LZMA_SPEC_POS (LZMA_POS_SLOT \
 271                        +(LZMA_NUM_LEN_TO_POS_STATES << LZMA_NUM_POS_SLOT_BITS))
 272 #define LZMA_ALIGN (LZMA_SPEC_POS \
 273                     + LZMA_NUM_FULL_DISTANCES - LZMA_END_POS_MODEL_INDEX)
 274 #define LZMA_LEN_CODER (LZMA_ALIGN + (1 << LZMA_NUM_ALIGN_BITS))
 275 #define LZMA_REP_LEN_CODER (LZMA_LEN_CODER + LZMA_NUM_LEN_PROBS)
 276 #define LZMA_LITERAL (LZMA_REP_LEN_CODER + LZMA_NUM_LEN_PROBS)
 277
 278
 279 struct writer {
 280         uint8_t *buffer;
 281         uint8_t previous_byte;
 282         size_t buffer_pos;
 283         int bufsize;
 284         size_t global_pos;
 285         long (*flush)(void*, unsigned long);
 286         struct lzma_header *header;
 287 };
 288
 289 struct cstate {
 290         int state;
 291         uint32_t rep0, rep1, rep2, rep3;
 292 };
 293
 294 static inline size_t INIT get_pos(struct writer *wr)
 295 {
 296         return
 297                 wr->global_pos + wr->buffer_pos;
 298 }
 299
 300 static inline uint8_t INIT peek_old_byte(struct writer *wr,
 301                                                 uint32_t offs)
 302 {
 303         if (!wr->flush) {
 304                 int32_t pos;
 305                 while (offs > wr->header->dict_size)
 306                         offs -= wr->header->dict_size;
 307                 pos = wr->buffer_pos - offs;
 308                 return wr->buffer[pos];
 309         } else {
 310                 uint32_t pos = wr->buffer_pos - offs;
 311                 while (pos >= wr->header->dict_size)
 312                         pos += wr->header->dict_size;
 313                 return wr->buffer[pos];
 314         }
 315
 316 }
 317
 318 static inline int INIT write_byte(struct writer *wr, uint8_t byte)
 319 {
 320         wr->buffer[wr->buffer_pos++] = wr->previous_byte = byte;
 321         if (wr->flush && wr->buffer_pos == wr->header->dict_size) {
 322                 wr->buffer_pos = 0;
 323                 wr->global_pos += wr->header->dict_size;
 324                 if (wr->flush((char *)wr->buffer, wr->header->dict_size)
 325                                 != wr->header->dict_size)
 326                         return -1;
 327         }
 328         return 0;
 329 }
 330
 331
 332 static inline int INIT copy_byte(struct writer *wr, uint32_t offs)
 333 {
 334         return write_byte(wr, peek_old_byte(wr, offs));
 335 }
 336
 337 static inline int INIT copy_bytes(struct writer *wr,
 338                                          uint32_t rep0, int len)
 339 {
 340         do {
 341                 if (copy_byte(wr, rep0))
 342                         return -1;
 343                 len--;
 344         } while (len != 0 && wr->buffer_pos < wr->header->dst_size);
 345
 346         return len;
 347 }
 348
 349 static inline int INIT process_bit0(struct writer *wr, struct rc *rc,
 350                                      struct cstate *cst, uint16_t *p,
 351                                      int pos_state, uint16_t *prob,
 352                                      int lc, uint32_t literal_pos_mask) {
 353         int mi = 1;
 354         rc_update_bit_0(rc, prob);
 355         prob = (p + LZMA_LITERAL +
 356                 (LZMA_LIT_SIZE
 357                  * (((get_pos(wr) & literal_pos_mask) << lc)
 358                     + (wr->previous_byte >> (8 - lc))))
 359                 );
 360
 361         if (cst->state >= LZMA_NUM_LIT_STATES) {
 362                 int match_byte = peek_old_byte(wr, cst->rep0);
 363                 do {
 364                         int bit;
 365                         uint16_t *prob_lit;
 366
 367                         match_byte <<= 1;
 368                         bit = match_byte & 0x100;
 369                         prob_lit = prob + 0x100 + bit + mi;
 370                         if (rc_get_bit(rc, prob_lit, &mi)) {
 371                                 if (!bit)
 372                                         break;
 373                         } else {
 374                                 if (bit)
 375                                         break;
 376                         }
 377                 } while (mi < 0x100);
 378         }
 379         while (mi < 0x100) {
 380                 uint16_t *prob_lit = prob + mi;
 381                 rc_get_bit(rc, prob_lit, &mi);
 382         }
 383         if (cst->state < 4)
 384                 cst->state = 0;
 385         else if (cst->state < 10)
 386                 cst->state -= 3;
 387         else
 388                 cst->state -= 6;
 389
 390         return write_byte(wr, mi);
 391 }
 392
 393 static inline int INIT process_bit1(struct writer *wr, struct rc *rc,
 394                                             struct cstate *cst, uint16_t *p,
 395                                             int pos_state, uint16_t *prob) {
 396         int offset;
 397         uint16_t *prob_len;
 398         int num_bits;
 399         int len;
 400
 401         rc_update_bit_1(rc, prob);
 402         prob = p + LZMA_IS_REP + cst->state;
 403         if (rc_is_bit_0(rc, prob)) {
 404                 rc_update_bit_0(rc, prob);
 405                 cst->rep3 = cst->rep2;
 406                 cst->rep2 = cst->rep1;
 407                 cst->rep1 = cst->rep0;
 408                 cst->state = cst->state < LZMA_NUM_LIT_STATES ? 0 : 3;
 409                 prob = p + LZMA_LEN_CODER;
 410         } else {
 411                 rc_update_bit_1(rc, prob);
 412                 prob = p + LZMA_IS_REP_G0 + cst->state;
 413                 if (rc_is_bit_0(rc, prob)) {
 414                         rc_update_bit_0(rc, prob);
 415                         prob = (p + LZMA_IS_REP_0_LONG
 416                                 + (cst->state <<
 417                                    LZMA_NUM_POS_BITS_MAX) +
 418                                 pos_state);
 419                         if (rc_is_bit_0(rc, prob)) {
 420                                 rc_update_bit_0(rc, prob);
 421
 422                                 cst->state = cst->state < LZMA_NUM_LIT_STATES ?
 423                                         9 : 11;
 424                                 return copy_byte(wr, cst->rep0);
 425                         } else {
 426                                 rc_update_bit_1(rc, prob);
 427                         }
 428                 } else {
 429                         uint32_t distance;
 430
 431                         rc_update_bit_1(rc, prob);
 432                         prob = p + LZMA_IS_REP_G1 + cst->state;
 433                         if (rc_is_bit_0(rc, prob)) {
 434                                 rc_update_bit_0(rc, prob);
 435                                 distance = cst->rep1;
 436                         } else {
 437                                 rc_update_bit_1(rc, prob);
 438                                 prob = p + LZMA_IS_REP_G2 + cst->state;
 439                                 if (rc_is_bit_0(rc, prob)) {
 440                                         rc_update_bit_0(rc, prob);
 441                                         distance = cst->rep2;
 442                                 } else {
 443                                         rc_update_bit_1(rc, prob);
 444                                         distance = cst->rep3;
 445                                         cst->rep3 = cst->rep2;
 446                                 }
 447                                 cst->rep2 = cst->rep1;
 448                         }
 449                         cst->rep1 = cst->rep0;
 450                         cst->rep0 = distance;
 451                 }
 452                 cst->state = cst->state < LZMA_NUM_LIT_STATES ? 8 : 11;
 453                 prob = p + LZMA_REP_LEN_CODER;
 454         }
 455
 456         prob_len = prob + LZMA_LEN_CHOICE;
 457         if (rc_is_bit_0(rc, prob_len)) {
 458                 rc_update_bit_0(rc, prob_len);
 459                 prob_len = (prob + LZMA_LEN_LOW
 460                             + (pos_state <<
 461                                LZMA_LEN_NUM_LOW_BITS));
 462                 offset = 0;
 463                 num_bits = LZMA_LEN_NUM_LOW_BITS;
 464         } else {
 465                 rc_update_bit_1(rc, prob_len);
 466                 prob_len = prob + LZMA_LEN_CHOICE_2;
 467                 if (rc_is_bit_0(rc, prob_len)) {
 468                         rc_update_bit_0(rc, prob_len);
 469                         prob_len = (prob + LZMA_LEN_MID
 470                                     + (pos_state <<
 471                                        LZMA_LEN_NUM_MID_BITS));
 472                         offset = 1 << LZMA_LEN_NUM_LOW_BITS;
 473                         num_bits = LZMA_LEN_NUM_MID_BITS;
 474                 } else {
 475                         rc_update_bit_1(rc, prob_len);
 476                         prob_len = prob + LZMA_LEN_HIGH;
 477                         offset = ((1 << LZMA_LEN_NUM_LOW_BITS)
 478                                   + (1 << LZMA_LEN_NUM_MID_BITS));
 479                         num_bits = LZMA_LEN_NUM_HIGH_BITS;
 480                 }
 481         }
 482
 483         rc_bit_tree_decode(rc, prob_len, num_bits, &len);
 484         len += offset;
 485
 486         if (cst->state < 4) {
 487                 int pos_slot;
 488
 489                 cst->state += LZMA_NUM_LIT_STATES;
 490                 prob =
 491                         p + LZMA_POS_SLOT +
 492                         ((len <
 493                           LZMA_NUM_LEN_TO_POS_STATES ? len :
 494                           LZMA_NUM_LEN_TO_POS_STATES - 1)
 495                          << LZMA_NUM_POS_SLOT_BITS);
 496                 rc_bit_tree_decode(rc, prob,
 497                                    LZMA_NUM_POS_SLOT_BITS,
 498                                    &pos_slot);
 499                 if (pos_slot >= LZMA_START_POS_MODEL_INDEX) {
 500                         int i, mi;
 501                         num_bits = (pos_slot >> 1) - 1;
 502                         cst->rep0 = 2 | (pos_slot & 1);
 503                         if (pos_slot < LZMA_END_POS_MODEL_INDEX) {
 504                                 cst->rep0 <<= num_bits;
 505                                 prob = p + LZMA_SPEC_POS +
 506                                         cst->rep0 - pos_slot - 1;
 507                         } else {
 508                                 num_bits -= LZMA_NUM_ALIGN_BITS;
 509                                 while (num_bits--)
 510                                         cst->rep0 = (cst->rep0 << 1) |
 511                                                 rc_direct_bit(rc);
 512                                 prob = p + LZMA_ALIGN;
 513                                 cst->rep0 <<= LZMA_NUM_ALIGN_BITS;
 514                                 num_bits = LZMA_NUM_ALIGN_BITS;
 515                         }
 516                         i = 1;
 517                         mi = 1;
 518                         while (num_bits--) {
 519                                 if (rc_get_bit(rc, prob + mi, &mi))
 520                                         cst->rep0 |= i;
 521                                 i <<= 1;
 522                         }
 523                 } else
 524                         cst->rep0 = pos_slot;
 525                 if (++(cst->rep0) == 0)
 526                         return 0;
 527                 if (cst->rep0 > wr->header->dict_size
 528                                 || cst->rep0 > get_pos(wr))
 529                         return -1;
 530         }
 531
 532         len += LZMA_MATCH_MIN_LEN;
 533
 534         return copy_bytes(wr, cst->rep0, len);
 535 }
 536
 537
 538
 539 STATIC inline int INIT unlzma(unsigned char *buf, long in_len,
 540                               long (*fill)(void*, unsigned long),
 541                               long (*flush)(void*, unsigned long),
 542                               unsigned char *output,
 543                               long *posp,
 544                               void(*error)(char *x)
 545         )
 546 {
 547         struct lzma_header header;
 548         int lc, pb, lp;
 549         uint32_t pos_state_mask;
 550         uint32_t literal_pos_mask;
 551         uint16_t *p;
 552         int num_probs;
 553         struct rc rc;
 554         int i, mi;
 555         struct writer wr;
 556         struct cstate cst;
 557         unsigned char *inbuf;
 558         int ret = -1;
 559
 560         rc.error = error;
 561
 562         if (buf)
 563                 inbuf = buf;
 564         else
 565                 inbuf = malloc(LZMA_IOBUF_SIZE);
 566         if (!inbuf) {
 567                 error("Could not allocate input buffer");
 568                 goto exit_0;
 569         }
 570
 571         cst.state = 0;
 572         cst.rep0 = cst.rep1 = cst.rep2 = cst.rep3 = 1;
 573
 574         wr.header = &header;
 575         wr.flush = flush;
 576         wr.global_pos = 0;
 577         wr.previous_byte = 0;
 578         wr.buffer_pos = 0;
 579
 580         rc_init(&rc, fill, inbuf, in_len);
 581
 582         for (i = 0; i < sizeof(header); i++) {
 583                 if (rc.ptr >= rc.buffer_end)
 584                         rc_read(&rc);
 585                 ((unsigned char *)&header)[i] = *rc.ptr++;
 586         }
 587
 588         if (header.pos >= (9 * 5 * 5)) {
 589                 error("bad header");
 590                 goto exit_1;
 591         }
 592
 593         mi = 0;
 594         lc = header.pos;
 595         while (lc >= 9) {
 596                 mi++;
 597                 lc -= 9;
 598         }
 599         pb = 0;
 600         lp = mi;
 601         while (lp >= 5) {
 602                 pb++;
 603                 lp -= 5;
 604         }
 605         pos_state_mask = (1 << pb) - 1;
 606         literal_pos_mask = (1 << lp) - 1;
 607
 608         ENDIAN_CONVERT(header.dict_size);
 609         ENDIAN_CONVERT(header.dst_size);
 610
 611         if (header.dict_size == 0)
 612                 header.dict_size = 1;
 613
 614         if (output)
 615                 wr.buffer = output;
 616         else {
 617                 wr.bufsize = MIN(header.dst_size, header.dict_size);
 618                 wr.buffer = large_malloc(wr.bufsize);
 619         }
 620         if (wr.buffer == NULL)
 621                 goto exit_1;
 622
 623         num_probs = LZMA_BASE_SIZE + (LZMA_LIT_SIZE << (lc + lp));
 624         p = (uint16_t *) large_malloc(num_probs * sizeof(*p));
 625         if (p == NULL)
 626                 goto exit_2;
 627         num_probs = LZMA_LITERAL + (LZMA_LIT_SIZE << (lc + lp));
 628         for (i = 0; i < num_probs; i++)
 629                 p[i] = (1 << RC_MODEL_TOTAL_BITS) >> 1;
 630
 631         rc_init_code(&rc);
 632
 633         while (get_pos(&wr) < header.dst_size) {
 634                 int pos_state = get_pos(&wr) & pos_state_mask;
 635                 uint16_t *prob = p + LZMA_IS_MATCH +
 636                         (cst.state << LZMA_NUM_POS_BITS_MAX) + pos_state;
 637                 if (rc_is_bit_0(&rc, prob)) {
 638                         if (process_bit0(&wr, &rc, &cst, p, pos_state, prob,
 639                                         lc, literal_pos_mask)) {
 640                                 error("LZMA data is corrupt");
 641                                 goto exit_3;
 642                         }
 643                 } else {
 644                         if (process_bit1(&wr, &rc, &cst, p, pos_state, prob)) {
 645                                 error("LZMA data is corrupt");
 646                                 goto exit_3;
 647                         }
 648                         if (cst.rep0 == 0)
 649                                 break;
 650                 }
 651                 if (rc.buffer_size <= 0)
 652                         goto exit_3;
 653         }
 654
 655         if (posp)
 656                 *posp = rc.ptr-rc.buffer;
 657         if (!wr.flush || wr.flush(wr.buffer, wr.buffer_pos) == wr.buffer_pos)
 658                 ret = 0;
 659 exit_3:
 660         large_free(p);
 661 exit_2:
 662         if (!output)
 663                 large_free(wr.buffer);
 664 exit_1:
 665         if (!buf)
 666                 free(inbuf);
 667 exit_0:
 668         return ret;
 669 }
 670
 671 #ifdef PREBOOT
 672 STATIC int INIT __decompress(unsigned char *buf, long in_len,
 673                               long (*fill)(void*, unsigned long),
 674                               long (*flush)(void*, unsigned long),
 675                               unsigned char *output, long out_len,
 676                               long *posp,
 677                               void (*error)(char *x))
 678 {
 679         return unlzma(buf, in_len - 4, fill, flush, output, posp, error);
 680 }
 681 #endif