1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * LZO1X Compressor from LZO
4 *
5 * Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com>
6 *
7 * The full LZO package can be found at:
8 * http://www.oberhumer.com/opensource/lzo/
9 *
10 * Changed for Linux kernel use by:
11 * Nitin Gupta <nitingupta910@gmail.com>
12 * Richard Purdie <rpurdie@openedhand.com>
13 */
14
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/unaligned.h>
18#include <linux/lzo.h>
19#include "lzodefs.h"
20
21#undef LZO_UNSAFE
22
23#ifndef LZO_SAFE
24#define LZO_UNSAFE 1
25#define LZO_SAFE(name) name
26#define HAVE_OP(x) 1
27#endif
28
29#define NEED_OP(x) if (unlikely(!HAVE_OP(x))) goto output_overrun
30
31static noinline int
32LZO_SAFE(lzo1x_1_do_compress)(const unsigned char *in, size_t in_len,
33 unsigned char **out, unsigned char *op_end,
34 size_t *tp, void *wrkmem,
35 signed char *state_offset,
36 const unsigned char bitstream_version)
37{
38 const unsigned char *ip;
39 unsigned char *op;
40 const unsigned char * const in_end = in + in_len;
41 const unsigned char * const ip_end = in + in_len - 20;
42 const unsigned char *ii;
43 lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
44 size_t ti = *tp;
45
46 op = *out;
47 ip = in;
48 ii = ip;
49 ip += ti < 4 ? 4 - ti : 0;
50
51 for (;;) {
52 const unsigned char *m_pos = NULL;
53 size_t t, m_len, m_off;
54 u32 dv;
55 u32 run_length = 0;
56literal:
57 ip += 1 + ((ip - ii) >> 5);
58next:
59 if (unlikely(ip >= ip_end))
60 break;
61 dv = get_unaligned_le32(p: ip);
62
63 if (dv == 0 && bitstream_version) {
64 const unsigned char *ir = ip + 4;
65 const unsigned char *limit = min(ip_end, ip + MAX_ZERO_RUN_LENGTH + 1);
66#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \
67 defined(LZO_FAST_64BIT_MEMORY_ACCESS)
68 u64 dv64;
69
70 for (; (ir + 32) <= limit; ir += 32) {
71 dv64 = get_unaligned((u64 *)ir);
72 dv64 |= get_unaligned((u64 *)ir + 1);
73 dv64 |= get_unaligned((u64 *)ir + 2);
74 dv64 |= get_unaligned((u64 *)ir + 3);
75 if (dv64)
76 break;
77 }
78 for (; (ir + 8) <= limit; ir += 8) {
79 dv64 = get_unaligned((u64 *)ir);
80 if (dv64) {
81# if defined(__LITTLE_ENDIAN)
82 ir += __builtin_ctzll(dv64) >> 3;
83# elif defined(__BIG_ENDIAN)
84 ir += __builtin_clzll(dv64) >> 3;
85# else
86# error "missing endian definition"
87# endif
88 break;
89 }
90 }
91#else
92 while ((ir < (const unsigned char *)
93 ALIGN((uintptr_t)ir, 4)) &&
94 (ir < limit) && (*ir == 0))
95 ir++;
96 if (IS_ALIGNED((uintptr_t)ir, 4)) {
97 for (; (ir + 4) <= limit; ir += 4) {
98 dv = *((u32 *)ir);
99 if (dv) {
100# if defined(__LITTLE_ENDIAN)
101 ir += __builtin_ctz(dv) >> 3;
102# elif defined(__BIG_ENDIAN)
103 ir += __builtin_clz(dv) >> 3;
104# else
105# error "missing endian definition"
106# endif
107 break;
108 }
109 }
110 }
111#endif
112 while (likely(ir < limit) && unlikely(*ir == 0))
113 ir++;
114 run_length = ir - ip;
115 if (run_length > MAX_ZERO_RUN_LENGTH)
116 run_length = MAX_ZERO_RUN_LENGTH;
117 } else {
118 t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
119 m_pos = in + dict[t];
120 dict[t] = (lzo_dict_t) (ip - in);
121 if (unlikely(dv != get_unaligned_le32(m_pos)))
122 goto literal;
123 }
124
125 ii -= ti;
126 ti = 0;
127 t = ip - ii;
128 if (t != 0) {
129 if (t <= 3) {
130 op[*state_offset] |= t;
131 NEED_OP(4);
132 COPY4(op, ii);
133 op += t;
134 } else if (t <= 16) {
135 NEED_OP(17);
136 *op++ = (t - 3);
137 COPY8(op, ii);
138 COPY8(op + 8, ii + 8);
139 op += t;
140 } else {
141 if (t <= 18) {
142 NEED_OP(1);
143 *op++ = (t - 3);
144 } else {
145 size_t tt = t - 18;
146 NEED_OP(1);
147 *op++ = 0;
148 while (unlikely(tt > 255)) {
149 tt -= 255;
150 NEED_OP(1);
151 *op++ = 0;
152 }
153 NEED_OP(1);
154 *op++ = tt;
155 }
156 NEED_OP(t);
157 do {
158 COPY8(op, ii);
159 COPY8(op + 8, ii + 8);
160 op += 16;
161 ii += 16;
162 t -= 16;
163 } while (t >= 16);
164 if (t > 0) do {
165 *op++ = *ii++;
166 } while (--t > 0);
167 }
168 }
169
170 if (unlikely(run_length)) {
171 ip += run_length;
172 run_length -= MIN_ZERO_RUN_LENGTH;
173 NEED_OP(4);
174 put_unaligned_le32(val: (run_length << 21) | 0xfffc18
175 | (run_length & 0x7), p: op);
176 op += 4;
177 run_length = 0;
178 *state_offset = -3;
179 goto finished_writing_instruction;
180 }
181
182 m_len = 4;
183 {
184#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
185 u64 v;
186 v = get_unaligned((const u64 *) (ip + m_len)) ^
187 get_unaligned((const u64 *) (m_pos + m_len));
188 if (unlikely(v == 0)) {
189 do {
190 m_len += 8;
191 v = get_unaligned((const u64 *) (ip + m_len)) ^
192 get_unaligned((const u64 *) (m_pos + m_len));
193 if (unlikely(ip + m_len >= ip_end))
194 goto m_len_done;
195 } while (v == 0);
196 }
197# if defined(__LITTLE_ENDIAN)
198 m_len += (unsigned) __builtin_ctzll(v) / 8;
199# elif defined(__BIG_ENDIAN)
200 m_len += (unsigned) __builtin_clzll(v) / 8;
201# else
202# error "missing endian definition"
203# endif
204#elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32)
205 u32 v;
206 v = get_unaligned((const u32 *) (ip + m_len)) ^
207 get_unaligned((const u32 *) (m_pos + m_len));
208 if (unlikely(v == 0)) {
209 do {
210 m_len += 4;
211 v = get_unaligned((const u32 *) (ip + m_len)) ^
212 get_unaligned((const u32 *) (m_pos + m_len));
213 if (v != 0)
214 break;
215 m_len += 4;
216 v = get_unaligned((const u32 *) (ip + m_len)) ^
217 get_unaligned((const u32 *) (m_pos + m_len));
218 if (unlikely(ip + m_len >= ip_end))
219 goto m_len_done;
220 } while (v == 0);
221 }
222# if defined(__LITTLE_ENDIAN)
223 m_len += (unsigned) __builtin_ctz(v) / 8;
224# elif defined(__BIG_ENDIAN)
225 m_len += (unsigned) __builtin_clz(v) / 8;
226# else
227# error "missing endian definition"
228# endif
229#else
230 if (unlikely(ip[m_len] == m_pos[m_len])) {
231 do {
232 m_len += 1;
233 if (ip[m_len] != m_pos[m_len])
234 break;
235 m_len += 1;
236 if (ip[m_len] != m_pos[m_len])
237 break;
238 m_len += 1;
239 if (ip[m_len] != m_pos[m_len])
240 break;
241 m_len += 1;
242 if (ip[m_len] != m_pos[m_len])
243 break;
244 m_len += 1;
245 if (ip[m_len] != m_pos[m_len])
246 break;
247 m_len += 1;
248 if (ip[m_len] != m_pos[m_len])
249 break;
250 m_len += 1;
251 if (ip[m_len] != m_pos[m_len])
252 break;
253 m_len += 1;
254 if (unlikely(ip + m_len >= ip_end))
255 goto m_len_done;
256 } while (ip[m_len] == m_pos[m_len]);
257 }
258#endif
259 }
260m_len_done:
261
262 m_off = ip - m_pos;
263 ip += m_len;
264 if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
265 m_off -= 1;
266 NEED_OP(2);
267 *op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2));
268 *op++ = (m_off >> 3);
269 } else if (m_off <= M3_MAX_OFFSET) {
270 m_off -= 1;
271 NEED_OP(1);
272 if (m_len <= M3_MAX_LEN)
273 *op++ = (M3_MARKER | (m_len - 2));
274 else {
275 m_len -= M3_MAX_LEN;
276 *op++ = M3_MARKER | 0;
277 while (unlikely(m_len > 255)) {
278 m_len -= 255;
279 NEED_OP(1);
280 *op++ = 0;
281 }
282 NEED_OP(1);
283 *op++ = (m_len);
284 }
285 NEED_OP(2);
286 *op++ = (m_off << 2);
287 *op++ = (m_off >> 6);
288 } else {
289 m_off -= 0x4000;
290 NEED_OP(1);
291 if (m_len <= M4_MAX_LEN)
292 *op++ = (M4_MARKER | ((m_off >> 11) & 8)
293 | (m_len - 2));
294 else {
295 if (unlikely(((m_off & 0x403f) == 0x403f)
296 && (m_len >= 261)
297 && (m_len <= 264))
298 && likely(bitstream_version)) {
299 // Under lzo-rle, block copies
300 // for 261 <= length <= 264 and
301 // (distance & 0x80f3) == 0x80f3
302 // can result in ambiguous
303 // output. Adjust length
304 // to 260 to prevent ambiguity.
305 ip -= m_len - 260;
306 m_len = 260;
307 }
308 m_len -= M4_MAX_LEN;
309 *op++ = (M4_MARKER | ((m_off >> 11) & 8));
310 while (unlikely(m_len > 255)) {
311 NEED_OP(1);
312 m_len -= 255;
313 *op++ = 0;
314 }
315 NEED_OP(1);
316 *op++ = (m_len);
317 }
318 NEED_OP(2);
319 *op++ = (m_off << 2);
320 *op++ = (m_off >> 6);
321 }
322 *state_offset = -2;
323finished_writing_instruction:
324 ii = ip;
325 goto next;
326 }
327 *out = op;
328 *tp = in_end - (ii - ti);
329 return LZO_E_OK;
330
331output_overrun:
332 return LZO_E_OUTPUT_OVERRUN;
333}
334
335static int LZO_SAFE(lzogeneric1x_1_compress)(
336 const unsigned char *in, size_t in_len,
337 unsigned char *out, size_t *out_len,
338 void *wrkmem, const unsigned char bitstream_version)
339{
340 unsigned char * const op_end = out + *out_len;
341 const unsigned char *ip = in;
342 unsigned char *op = out;
343 unsigned char *data_start;
344 size_t l = in_len;
345 size_t t = 0;
346 signed char state_offset = -2;
347 unsigned int m4_max_offset;
348
349 // LZO v0 will never write 17 as first byte (except for zero-length
350 // input), so this is used to version the bitstream
351 if (bitstream_version > 0) {
352 *op++ = 17;
353 *op++ = bitstream_version;
354 m4_max_offset = M4_MAX_OFFSET_V1;
355 } else {
356 m4_max_offset = M4_MAX_OFFSET_V0;
357 }
358
359 data_start = op;
360
361 while (l > 20) {
362 size_t ll = min_t(size_t, l, m4_max_offset + 1);
363 uintptr_t ll_end = (uintptr_t) ip + ll;
364 int err;
365
366 if ((ll_end + ((t + ll) >> 5)) <= ll_end)
367 break;
368 BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
369 memset(s: wrkmem, c: 0, D_SIZE * sizeof(lzo_dict_t));
370 err = LZO_SAFE(lzo1x_1_do_compress)(
371 in: ip, in_len: ll, out: &op, op_end, tp: &t, wrkmem,
372 state_offset: &state_offset, bitstream_version);
373 if (err != LZO_E_OK)
374 return err;
375 ip += ll;
376 l -= ll;
377 }
378 t += l;
379
380 if (t > 0) {
381 const unsigned char *ii = in + in_len - t;
382
383 if (op == data_start && t <= 238) {
384 NEED_OP(1);
385 *op++ = (17 + t);
386 } else if (t <= 3) {
387 op[state_offset] |= t;
388 } else if (t <= 18) {
389 NEED_OP(1);
390 *op++ = (t - 3);
391 } else {
392 size_t tt = t - 18;
393 NEED_OP(1);
394 *op++ = 0;
395 while (tt > 255) {
396 tt -= 255;
397 NEED_OP(1);
398 *op++ = 0;
399 }
400 NEED_OP(1);
401 *op++ = tt;
402 }
403 NEED_OP(t);
404 if (t >= 16) do {
405 COPY8(op, ii);
406 COPY8(op + 8, ii + 8);
407 op += 16;
408 ii += 16;
409 t -= 16;
410 } while (t >= 16);
411 if (t > 0) do {
412 *op++ = *ii++;
413 } while (--t > 0);
414 }
415
416 NEED_OP(3);
417 *op++ = M4_MARKER | 1;
418 *op++ = 0;
419 *op++ = 0;
420
421 *out_len = op - out;
422 return LZO_E_OK;
423
424output_overrun:
425 return LZO_E_OUTPUT_OVERRUN;
426}
427
428int LZO_SAFE(lzo1x_1_compress)(const unsigned char *in, size_t in_len,
429 unsigned char *out, size_t *out_len,
430 void *wrkmem)
431{
432 return LZO_SAFE(lzogeneric1x_1_compress)(
433 in, in_len, out, out_len, wrkmem, bitstream_version: 0);
434}
435
436int LZO_SAFE(lzorle1x_1_compress)(const unsigned char *in, size_t in_len,
437 unsigned char *out, size_t *out_len,
438 void *wrkmem)
439{
440 return LZO_SAFE(lzogeneric1x_1_compress)(
441 in, in_len, out, out_len, wrkmem, LZO_VERSION);
442}
443
444EXPORT_SYMBOL_GPL(LZO_SAFE(lzo1x_1_compress));
445EXPORT_SYMBOL_GPL(LZO_SAFE(lzorle1x_1_compress));
446
447#ifndef LZO_UNSAFE
448MODULE_LICENSE("GPL");
449MODULE_DESCRIPTION("LZO1X-1 Compressor");
450#endif
451