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Huang Jianan26c7fda2022-02-26 15:05:48 +08001// SPDX-License-Identifier: GPL 2.0+ OR BSD-2-Clause
Julius Werner027b7282015-10-06 20:03:53 -07002/*
Huang Jianan26c7fda2022-02-26 15:05:48 +08003 * LZ4 - Fast LZ compression algorithm
4 * Copyright (C) 2011 - 2016, Yann Collet.
5 * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met:
9 * * Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 * You can contact the author at :
27 * - LZ4 homepage : http://www.lz4.org
28 * - LZ4 source repository : https://github.com/lz4/lz4
29 */
Huang Jianan26c7fda2022-02-26 15:05:48 +080030#include <compiler.h>
31#include <linux/kernel.h>
32#include <linux/types.h>
33#include <linux/bug.h>
34#include <asm/unaligned.h>
35#include <u-boot/lz4.h>
Julius Werner027b7282015-10-06 20:03:53 -070036
Huang Jianan26c7fda2022-02-26 15:05:48 +080037#define FORCE_INLINE inline __attribute__((always_inline))
Julius Werner027b7282015-10-06 20:03:53 -070038
Huang Jianan26c7fda2022-02-26 15:05:48 +080039static FORCE_INLINE u16 LZ4_readLE16(const void *src)
40{
41 return get_unaligned_le16(src);
42}
43
44static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
45{
46 put_unaligned(get_unaligned((const u64 *)src), (u64 *)dst);
47}
48
49typedef uint8_t BYTE;
50typedef uint16_t U16;
51typedef uint32_t U32;
52typedef int32_t S32;
53typedef uint64_t U64;
54typedef uintptr_t uptrval;
55
56static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
57{
58 put_unaligned(value, (U32 *)memPtr);
59}
Julius Werner027b7282015-10-06 20:03:53 -070060
61/**************************************
62* Reading and writing into memory
63**************************************/
64
65/* customized version of memcpy, which may overwrite up to 7 bytes beyond dstEnd */
66static void LZ4_wildCopy(void* dstPtr, const void* srcPtr, void* dstEnd)
67{
68 BYTE* d = (BYTE*)dstPtr;
69 const BYTE* s = (const BYTE*)srcPtr;
70 BYTE* e = (BYTE*)dstEnd;
71 do { LZ4_copy8(d,s); d+=8; s+=8; } while (d<e);
72}
73
74
75/**************************************
76* Common Constants
77**************************************/
78#define MINMATCH 4
79
Huang Jianan26c7fda2022-02-26 15:05:48 +080080#define WILDCOPYLENGTH 8
Julius Werner027b7282015-10-06 20:03:53 -070081#define LASTLITERALS 5
Huang Jianan26c7fda2022-02-26 15:05:48 +080082#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
Julius Werner027b7282015-10-06 20:03:53 -070083
Huang Jianan26c7fda2022-02-26 15:05:48 +080084/*
85 * ensure it's possible to write 2 x wildcopyLength
86 * without overflowing output buffer
87 */
88#define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH)
89
90#define KB (1 <<10)
Julius Werner027b7282015-10-06 20:03:53 -070091
92#define MAXD_LOG 16
93#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
94
95#define ML_BITS 4
96#define ML_MASK ((1U<<ML_BITS)-1)
97#define RUN_BITS (8-ML_BITS)
98#define RUN_MASK ((1U<<RUN_BITS)-1)
99
Huang Jianan26c7fda2022-02-26 15:05:48 +0800100#define LZ4_STATIC_ASSERT(c) BUILD_BUG_ON(!(c))
Julius Werner027b7282015-10-06 20:03:53 -0700101
102/**************************************
103* Local Structures and types
104**************************************/
105typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
106typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
Huang Jianan26c7fda2022-02-26 15:05:48 +0800107typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;
Julius Werner027b7282015-10-06 20:03:53 -0700108
Huang Jianan26c7fda2022-02-26 15:05:48 +0800109#define DEBUGLOG(l, ...) {} /* disabled */
Julius Werner027b7282015-10-06 20:03:53 -0700110
Huang Jianan26c7fda2022-02-26 15:05:48 +0800111#ifndef assert
112#define assert(condition) ((void)0)
113#endif
Julius Werner027b7282015-10-06 20:03:53 -0700114
Julius Werner027b7282015-10-06 20:03:53 -0700115/*
Huang Jianan26c7fda2022-02-26 15:05:48 +0800116 * LZ4_decompress_generic() :
117 * This generic decompression function covers all use cases.
118 * It shall be instantiated several times, using different sets of directives.
119 * Note that it is important for performance that this function really get inlined,
Julius Werner027b7282015-10-06 20:03:53 -0700120 * in order to remove useless branches during compilation optimization.
121 */
Huang Jianan26c7fda2022-02-26 15:05:48 +0800122static FORCE_INLINE int LZ4_decompress_generic(
123 const char * const src,
124 char * const dst,
125 int srcSize,
126 /*
127 * If endOnInput == endOnInputSize,
128 * this value is `dstCapacity`
129 */
130 int outputSize,
131 /* endOnOutputSize, endOnInputSize */
132 endCondition_directive endOnInput,
133 /* full, partial */
134 earlyEnd_directive partialDecoding,
135 /* noDict, withPrefix64k, usingExtDict */
136 dict_directive dict,
137 /* always <= dst, == dst when no prefix */
138 const BYTE * const lowPrefix,
139 /* only if dict == usingExtDict */
140 const BYTE * const dictStart,
141 /* note : = 0 if noDict */
142 const size_t dictSize
143 )
Julius Werner027b7282015-10-06 20:03:53 -0700144{
Huang Jianan26c7fda2022-02-26 15:05:48 +0800145 const BYTE *ip = (const BYTE *) src;
146 const BYTE * const iend = ip + srcSize;
Julius Werner027b7282015-10-06 20:03:53 -0700147
Huang Jianan26c7fda2022-02-26 15:05:48 +0800148 BYTE *op = (BYTE *) dst;
149 BYTE * const oend = op + outputSize;
150 BYTE *cpy;
Julius Werner027b7282015-10-06 20:03:53 -0700151
Huang Jianan26c7fda2022-02-26 15:05:48 +0800152 const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize;
153 static const unsigned int inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
154 static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};
Julius Werner027b7282015-10-06 20:03:53 -0700155
Huang Jianan26c7fda2022-02-26 15:05:48 +0800156 const int safeDecode = (endOnInput == endOnInputSize);
157 const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB)));
Julius Werner027b7282015-10-06 20:03:53 -0700158
Huang Jianan26c7fda2022-02-26 15:05:48 +0800159 /* Set up the "end" pointers for the shortcut. */
160 const BYTE *const shortiend = iend -
161 (endOnInput ? 14 : 8) /*maxLL*/ - 2 /*offset*/;
162 const BYTE *const shortoend = oend -
163 (endOnInput ? 14 : 8) /*maxLL*/ - 18 /*maxML*/;
Julius Werner027b7282015-10-06 20:03:53 -0700164
Huang Jianan26c7fda2022-02-26 15:05:48 +0800165 DEBUGLOG(5, "%s (srcSize:%i, dstSize:%i)", __func__,
166 srcSize, outputSize);
Julius Werner027b7282015-10-06 20:03:53 -0700167
Huang Jianan26c7fda2022-02-26 15:05:48 +0800168 /* Special cases */
169 assert(lowPrefix <= op);
170 assert(src != NULL);
Julius Werner027b7282015-10-06 20:03:53 -0700171
Huang Jianan26c7fda2022-02-26 15:05:48 +0800172 /* Empty output buffer */
173 if ((endOnInput) && (unlikely(outputSize == 0)))
174 return ((srcSize == 1) && (*ip == 0)) ? 0 : -1;
Julius Werner027b7282015-10-06 20:03:53 -0700175
Huang Jianan26c7fda2022-02-26 15:05:48 +0800176 if ((!endOnInput) && (unlikely(outputSize == 0)))
177 return (*ip == 0 ? 1 : -1);
Julius Werner027b7282015-10-06 20:03:53 -0700178
Huang Jianan26c7fda2022-02-26 15:05:48 +0800179 if ((endOnInput) && unlikely(srcSize == 0))
180 return -1;
Julius Werner027b7282015-10-06 20:03:53 -0700181
Huang Jianan26c7fda2022-02-26 15:05:48 +0800182 /* Main Loop : decode sequences */
183 while (1) {
184 size_t length;
185 const BYTE *match;
186 size_t offset;
Julius Werner027b7282015-10-06 20:03:53 -0700187
Huang Jianan26c7fda2022-02-26 15:05:48 +0800188 /* get literal length */
189 unsigned int const token = *ip++;
190 length = token>>ML_BITS;
Julius Werner027b7282015-10-06 20:03:53 -0700191
Huang Jianan26c7fda2022-02-26 15:05:48 +0800192 /* ip < iend before the increment */
193 assert(!endOnInput || ip <= iend);
Julius Werner027b7282015-10-06 20:03:53 -0700194
Huang Jianan26c7fda2022-02-26 15:05:48 +0800195 /*
196 * A two-stage shortcut for the most common case:
197 * 1) If the literal length is 0..14, and there is enough
198 * space, enter the shortcut and copy 16 bytes on behalf
199 * of the literals (in the fast mode, only 8 bytes can be
200 * safely copied this way).
201 * 2) Further if the match length is 4..18, copy 18 bytes
202 * in a similar manner; but we ensure that there's enough
203 * space in the output for those 18 bytes earlier, upon
204 * entering the shortcut (in other words, there is a
205 * combined check for both stages).
206 *
207 * The & in the likely() below is intentionally not && so that
208 * some compilers can produce better parallelized runtime code
209 */
210 if ((endOnInput ? length != RUN_MASK : length <= 8)
211 /*
212 * strictly "less than" on input, to re-enter
213 * the loop with at least one byte
214 */
215 && likely((endOnInput ? ip < shortiend : 1) &
216 (op <= shortoend))) {
217 /* Copy the literals */
218 memcpy(op, ip, endOnInput ? 16 : 8);
219 op += length; ip += length;
Julius Werner027b7282015-10-06 20:03:53 -0700220
Huang Jianan26c7fda2022-02-26 15:05:48 +0800221 /*
222 * The second stage:
223 * prepare for match copying, decode full info.
224 * If it doesn't work out, the info won't be wasted.
225 */
226 length = token & ML_MASK; /* match length */
227 offset = LZ4_readLE16(ip);
228 ip += 2;
229 match = op - offset;
230 assert(match <= op); /* check overflow */
Julius Werner027b7282015-10-06 20:03:53 -0700231
Huang Jianan26c7fda2022-02-26 15:05:48 +0800232 /* Do not deal with overlapping matches. */
233 if ((length != ML_MASK) &&
234 (offset >= 8) &&
235 (dict == withPrefix64k || match >= lowPrefix)) {
236 /* Copy the match. */
237 memcpy(op + 0, match + 0, 8);
238 memcpy(op + 8, match + 8, 8);
239 memcpy(op + 16, match + 16, 2);
240 op += length + MINMATCH;
241 /* Both stages worked, load the next token. */
242 continue;
243 }
Julius Werner027b7282015-10-06 20:03:53 -0700244
Huang Jianan26c7fda2022-02-26 15:05:48 +0800245 /*
246 * The second stage didn't work out, but the info
247 * is ready. Propel it right to the point of match
248 * copying.
249 */
250 goto _copy_match;
251 }
Julius Werner027b7282015-10-06 20:03:53 -0700252
Huang Jianan26c7fda2022-02-26 15:05:48 +0800253 /* decode literal length */
254 if (length == RUN_MASK) {
255 unsigned int s;
256
257 if (unlikely(endOnInput ? ip >= iend - RUN_MASK : 0)) {
258 /* overflow detection */
259 goto _output_error;
260 }
261 do {
262 s = *ip++;
263 length += s;
264 } while (likely(endOnInput
265 ? ip < iend - RUN_MASK
266 : 1) & (s == 255));
267
268 if ((safeDecode)
269 && unlikely((uptrval)(op) +
270 length < (uptrval)(op))) {
271 /* overflow detection */
272 goto _output_error;
273 }
274 if ((safeDecode)
275 && unlikely((uptrval)(ip) +
276 length < (uptrval)(ip))) {
277 /* overflow detection */
278 goto _output_error;
279 }
280 }
281
282 /* copy literals */
283 cpy = op + length;
284 LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);
285
286 if (((endOnInput) && ((cpy > oend - MFLIMIT)
287 || (ip + length > iend - (2 + 1 + LASTLITERALS))))
288 || ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) {
289 if (partialDecoding) {
290 if (cpy > oend) {
291 /*
292 * Partial decoding :
293 * stop in the middle of literal segment
294 */
295 cpy = oend;
296 length = oend - op;
297 }
298 if ((endOnInput)
299 && (ip + length > iend)) {
300 /*
301 * Error :
302 * read attempt beyond
303 * end of input buffer
304 */
305 goto _output_error;
306 }
307 } else {
308 if ((!endOnInput)
309 && (cpy != oend)) {
310 /*
311 * Error :
312 * block decoding must
313 * stop exactly there
314 */
315 goto _output_error;
316 }
317 if ((endOnInput)
318 && ((ip + length != iend)
319 || (cpy > oend))) {
320 /*
321 * Error :
322 * input must be consumed
323 */
324 goto _output_error;
325 }
326 }
327
328 /*
329 * supports overlapping memory regions; only matters
330 * for in-place decompression scenarios
331 */
332 memmove(op, ip, length);
333 ip += length;
334 op += length;
335
336 /* Necessarily EOF, due to parsing restrictions */
337 if (!partialDecoding || (cpy == oend))
338 break;
339 } else {
340 /* may overwrite up to WILDCOPYLENGTH beyond cpy */
341 LZ4_wildCopy(op, ip, cpy);
342 ip += length;
343 op = cpy;
344 }
345
346 /* get offset */
347 offset = LZ4_readLE16(ip);
348 ip += 2;
349 match = op - offset;
350
351 /* get matchlength */
352 length = token & ML_MASK;
353
354_copy_match:
355 if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) {
356 /* Error : offset outside buffers */
357 goto _output_error;
358 }
359
360 /* costs ~1%; silence an msan warning when offset == 0 */
361 /*
362 * note : when partialDecoding, there is no guarantee that
363 * at least 4 bytes remain available in output buffer
364 */
365 if (!partialDecoding) {
366 assert(oend > op);
367 assert(oend - op >= 4);
368
369 LZ4_write32(op, (U32)offset);
370 }
371
372 if (length == ML_MASK) {
373 unsigned int s;
374
375 do {
376 s = *ip++;
377
378 if ((endOnInput) && (ip > iend - LASTLITERALS))
379 goto _output_error;
380
381 length += s;
382 } while (s == 255);
383
384 if ((safeDecode)
385 && unlikely(
386 (uptrval)(op) + length < (uptrval)op)) {
387 /* overflow detection */
388 goto _output_error;
389 }
390 }
391
392 length += MINMATCH;
393
394 /* match starting within external dictionary */
395 if ((dict == usingExtDict) && (match < lowPrefix)) {
396 if (unlikely(op + length > oend - LASTLITERALS)) {
397 /* doesn't respect parsing restriction */
398 if (!partialDecoding)
399 goto _output_error;
400 length = min(length, (size_t)(oend - op));
401 }
402
403 if (length <= (size_t)(lowPrefix - match)) {
404 /*
405 * match fits entirely within external
406 * dictionary : just copy
407 */
408 memmove(op, dictEnd - (lowPrefix - match),
409 length);
410 op += length;
411 } else {
412 /*
413 * match stretches into both external
414 * dictionary and current block
415 */
416 size_t const copySize = (size_t)(lowPrefix - match);
417 size_t const restSize = length - copySize;
418
419 memcpy(op, dictEnd - copySize, copySize);
420 op += copySize;
421 if (restSize > (size_t)(op - lowPrefix)) {
422 /* overlap copy */
423 BYTE * const endOfMatch = op + restSize;
424 const BYTE *copyFrom = lowPrefix;
425
426 while (op < endOfMatch)
427 *op++ = *copyFrom++;
428 } else {
429 memcpy(op, lowPrefix, restSize);
430 op += restSize;
431 }
432 }
433 continue;
434 }
435
436 /* copy match within block */
437 cpy = op + length;
438
439 /*
440 * partialDecoding :
441 * may not respect endBlock parsing restrictions
442 */
443 assert(op <= oend);
444 if (partialDecoding &&
445 (cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
446 size_t const mlen = min(length, (size_t)(oend - op));
447 const BYTE * const matchEnd = match + mlen;
448 BYTE * const copyEnd = op + mlen;
449
450 if (matchEnd > op) {
451 /* overlap copy */
452 while (op < copyEnd)
453 *op++ = *match++;
454 } else {
455 memcpy(op, match, mlen);
456 }
457 op = copyEnd;
458 if (op == oend)
459 break;
460 continue;
461 }
462
463 if (unlikely(offset < 8)) {
464 op[0] = match[0];
465 op[1] = match[1];
466 op[2] = match[2];
467 op[3] = match[3];
468 match += inc32table[offset];
469 memcpy(op + 4, match, 4);
470 match -= dec64table[offset];
471 } else {
472 LZ4_copy8(op, match);
473 match += 8;
474 }
475
476 op += 8;
477
478 if (unlikely(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
479 BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);
480
481 if (cpy > oend - LASTLITERALS) {
482 /*
483 * Error : last LASTLITERALS bytes
484 * must be literals (uncompressed)
485 */
486 goto _output_error;
487 }
488
489 if (op < oCopyLimit) {
490 LZ4_wildCopy(op, match, oCopyLimit);
491 match += oCopyLimit - op;
492 op = oCopyLimit;
493 }
494 while (op < cpy)
495 *op++ = *match++;
496 } else {
497 LZ4_copy8(op, match);
498 if (length > 16)
499 LZ4_wildCopy(op + 8, match + 8, cpy);
500 }
501 op = cpy; /* wildcopy correction */
502 }
503
504 /* end of decoding */
505 if (endOnInput) {
506 /* Nb of output bytes decoded */
507 return (int) (((char *)op) - dst);
508 } else {
509 /* Nb of input bytes read */
510 return (int) (((const char *)ip) - src);
511 }
512
513 /* Overflow error detected */
Julius Werner027b7282015-10-06 20:03:53 -0700514_output_error:
Huang Jianan26c7fda2022-02-26 15:05:48 +0800515 return (int) (-(((const char *)ip) - src)) - 1;
516}
517
518int LZ4_decompress_safe(const char *source, char *dest,
519 int compressedSize, int maxDecompressedSize)
520{
521 return LZ4_decompress_generic(source, dest,
522 compressedSize, maxDecompressedSize,
523 endOnInputSize, decode_full_block,
524 noDict, (BYTE *)dest, NULL, 0);
525}
526
527int LZ4_decompress_safe_partial(const char *src, char *dst,
528 int compressedSize, int targetOutputSize, int dstCapacity)
529{
530 dstCapacity = min(targetOutputSize, dstCapacity);
531 return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
532 endOnInputSize, partial_decode,
533 noDict, (BYTE *)dst, NULL, 0);
Julius Werner027b7282015-10-06 20:03:53 -0700534}