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