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1/*
2 * LZO1X Compressor from MiniLZO
3 *
4 * Copyright (C) 1996-2005 Markus F.X.J. Oberhumer <markus@oberhumer.com>
5 *
6 * The full LZO package can be found at:
7 * http://www.oberhumer.com/opensource/lzo/
8 *
9 * Changed for kernel use by:
10 * Nitin Gupta <nitingupta910@gmail.com>
11 * Richard Purdie <rpurdie@openedhand.com>
12 */
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/lzo.h>
17#include <asm/unaligned.h>
18#include "lzodefs.h"
19
20static noinline size_t
21_lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
22 unsigned char *out, size_t *out_len, void *wrkmem)
23{
24 const unsigned char * const in_end = in + in_len;
25 const unsigned char * const ip_end = in + in_len - M2_MAX_LEN - 5;
26 const unsigned char ** const dict = wrkmem;
27 const unsigned char *ip = in, *ii = ip;
28 const unsigned char *end, *m, *m_pos;
29 size_t m_off, m_len, dindex;
30 unsigned char *op = out;
31
32 ip += 4;
33
34 for (;;) {
35 dindex = ((size_t)(0x21 * DX3(ip, 5, 5, 6)) >> 5) & D_MASK;
36 m_pos = dict[dindex];
37
38 if (m_pos < in)
39 goto literal;
40
41 if (ip == m_pos || ((size_t)(ip - m_pos) > M4_MAX_OFFSET))
42 goto literal;
43
44 m_off = ip - m_pos;
45 if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
46 goto try_match;
47
48 dindex = (dindex & (D_MASK & 0x7ff)) ^ (D_HIGH | 0x1f);
49 m_pos = dict[dindex];
50
51 if (m_pos < in)
52 goto literal;
53
54 if (ip == m_pos || ((size_t)(ip - m_pos) > M4_MAX_OFFSET))
55 goto literal;
56
57 m_off = ip - m_pos;
58 if (m_off <= M2_MAX_OFFSET || m_pos[3] == ip[3])
59 goto try_match;
60
61 goto literal;
62
63try_match:
64 if (get_unaligned((const unsigned short *)m_pos)
65 == get_unaligned((const unsigned short *)ip)) {
66 if (likely(m_pos[2] == ip[2]))
67 goto match;
68 }
69
70literal:
71 dict[dindex] = ip;
72 ++ip;
73 if (unlikely(ip >= ip_end))
74 break;
75 continue;
76
77match:
78 dict[dindex] = ip;
79 if (ip != ii) {
80 size_t t = ip - ii;
81
82 if (t <= 3) {
83 op[-2] |= t;
84 } else if (t <= 18) {
85 *op++ = (t - 3);
86 } else {
87 size_t tt = t - 18;
88
89 *op++ = 0;
90 while (tt > 255) {
91 tt -= 255;
92 *op++ = 0;
93 }
94 *op++ = tt;
95 }
96 do {
97 *op++ = *ii++;
98 } while (--t > 0);
99 }
100
101 ip += 3;
102 if (m_pos[3] != *ip++ || m_pos[4] != *ip++
103 || m_pos[5] != *ip++ || m_pos[6] != *ip++
104 || m_pos[7] != *ip++ || m_pos[8] != *ip++) {
105 --ip;
106 m_len = ip - ii;
107
108 if (m_off <= M2_MAX_OFFSET) {
109 m_off -= 1;
110 *op++ = (((m_len - 1) << 5)
111 | ((m_off & 7) << 2));
112 *op++ = (m_off >> 3);
113 } else if (m_off <= M3_MAX_OFFSET) {
114 m_off -= 1;
115 *op++ = (M3_MARKER | (m_len - 2));
116 goto m3_m4_offset;
117 } else {
118 m_off -= 0x4000;
119
120 *op++ = (M4_MARKER | ((m_off & 0x4000) >> 11)
121 | (m_len - 2));
122 goto m3_m4_offset;
123 }
124 } else {
125 end = in_end;
126 m = m_pos + M2_MAX_LEN + 1;
127
128 while (ip < end && *m == *ip) {
129 m++;
130 ip++;
131 }
132 m_len = ip - ii;
133
134 if (m_off <= M3_MAX_OFFSET) {
135 m_off -= 1;
136 if (m_len <= 33) {
137 *op++ = (M3_MARKER | (m_len - 2));
138 } else {
139 m_len -= 33;
140 *op++ = M3_MARKER | 0;
141 goto m3_m4_len;
142 }
143 } else {
144 m_off -= 0x4000;
145 if (m_len <= M4_MAX_LEN) {
146 *op++ = (M4_MARKER
147 | ((m_off & 0x4000) >> 11)
148 | (m_len - 2));
149 } else {
150 m_len -= M4_MAX_LEN;
151 *op++ = (M4_MARKER
152 | ((m_off & 0x4000) >> 11));
153m3_m4_len:
154 while (m_len > 255) {
155 m_len -= 255;
156 *op++ = 0;
157 }
158
159 *op++ = (m_len);
160 }
161 }
162m3_m4_offset:
163 *op++ = ((m_off & 63) << 2);
164 *op++ = (m_off >> 6);
165 }
166
167 ii = ip;
168 if (unlikely(ip >= ip_end))
169 break;
170 }
171
172 *out_len = op - out;
173 return in_end - ii;
174}
175
176int lzo1x_1_compress(const unsigned char *in, size_t in_len, unsigned char *out,
177 size_t *out_len, void *wrkmem)
178{
179 const unsigned char *ii;
180 unsigned char *op = out;
181 size_t t;
182
183 if (unlikely(in_len <= M2_MAX_LEN + 5)) {
184 t = in_len;
185 } else {
186 t = _lzo1x_1_do_compress(in, in_len, op, out_len, wrkmem);
187 op += *out_len;
188 }
189
190 if (t > 0) {
191 ii = in + in_len - t;
192
193 if (op == out && t <= 238) {
194 *op++ = (17 + t);
195 } else if (t <= 3) {
196 op[-2] |= t;
197 } else if (t <= 18) {
198 *op++ = (t - 3);
199 } else {
200 size_t tt = t - 18;
201
202 *op++ = 0;
203 while (tt > 255) {
204 tt -= 255;
205 *op++ = 0;
206 }
207
208 *op++ = tt;
209 }
210 do {
211 *op++ = *ii++;
212 } while (--t > 0);
213 }
214
215 *op++ = M4_MARKER | 1;
216 *op++ = 0;
217 *op++ = 0;
218
219 *out_len = op - out;
220 return LZO_E_OK;
221}
222EXPORT_SYMBOL_GPL(lzo1x_1_compress);
223
224MODULE_LICENSE("GPL");
225MODULE_DESCRIPTION("LZO1X-1 Compressor");
226
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
21static noinline size_t
22lzo1x_1_do_compress(const unsigned char *in, size_t in_len,
23 unsigned char *out, size_t *out_len,
24 size_t ti, void *wrkmem, signed char *state_offset,
25 const unsigned char bitstream_version)
26{
27 const unsigned char *ip;
28 unsigned char *op;
29 const unsigned char * const in_end = in + in_len;
30 const unsigned char * const ip_end = in + in_len - 20;
31 const unsigned char *ii;
32 lzo_dict_t * const dict = (lzo_dict_t *) wrkmem;
33
34 op = out;
35 ip = in;
36 ii = ip;
37 ip += ti < 4 ? 4 - ti : 0;
38
39 for (;;) {
40 const unsigned char *m_pos = NULL;
41 size_t t, m_len, m_off;
42 u32 dv;
43 u32 run_length = 0;
44literal:
45 ip += 1 + ((ip - ii) >> 5);
46next:
47 if (unlikely(ip >= ip_end))
48 break;
49 dv = get_unaligned_le32(ip);
50
51 if (dv == 0 && bitstream_version) {
52 const unsigned char *ir = ip + 4;
53 const unsigned char *limit = min(ip_end, ip + MAX_ZERO_RUN_LENGTH + 1);
54#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \
55 defined(LZO_FAST_64BIT_MEMORY_ACCESS)
56 u64 dv64;
57
58 for (; (ir + 32) <= limit; ir += 32) {
59 dv64 = get_unaligned((u64 *)ir);
60 dv64 |= get_unaligned((u64 *)ir + 1);
61 dv64 |= get_unaligned((u64 *)ir + 2);
62 dv64 |= get_unaligned((u64 *)ir + 3);
63 if (dv64)
64 break;
65 }
66 for (; (ir + 8) <= limit; ir += 8) {
67 dv64 = get_unaligned((u64 *)ir);
68 if (dv64) {
69# if defined(__LITTLE_ENDIAN)
70 ir += __builtin_ctzll(dv64) >> 3;
71# elif defined(__BIG_ENDIAN)
72 ir += __builtin_clzll(dv64) >> 3;
73# else
74# error "missing endian definition"
75# endif
76 break;
77 }
78 }
79#else
80 while ((ir < (const unsigned char *)
81 ALIGN((uintptr_t)ir, 4)) &&
82 (ir < limit) && (*ir == 0))
83 ir++;
84 if (IS_ALIGNED((uintptr_t)ir, 4)) {
85 for (; (ir + 4) <= limit; ir += 4) {
86 dv = *((u32 *)ir);
87 if (dv) {
88# if defined(__LITTLE_ENDIAN)
89 ir += __builtin_ctz(dv) >> 3;
90# elif defined(__BIG_ENDIAN)
91 ir += __builtin_clz(dv) >> 3;
92# else
93# error "missing endian definition"
94# endif
95 break;
96 }
97 }
98 }
99#endif
100 while (likely(ir < limit) && unlikely(*ir == 0))
101 ir++;
102 run_length = ir - ip;
103 if (run_length > MAX_ZERO_RUN_LENGTH)
104 run_length = MAX_ZERO_RUN_LENGTH;
105 } else {
106 t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK;
107 m_pos = in + dict[t];
108 dict[t] = (lzo_dict_t) (ip - in);
109 if (unlikely(dv != get_unaligned_le32(m_pos)))
110 goto literal;
111 }
112
113 ii -= ti;
114 ti = 0;
115 t = ip - ii;
116 if (t != 0) {
117 if (t <= 3) {
118 op[*state_offset] |= t;
119 COPY4(op, ii);
120 op += t;
121 } else if (t <= 16) {
122 *op++ = (t - 3);
123 COPY8(op, ii);
124 COPY8(op + 8, ii + 8);
125 op += t;
126 } else {
127 if (t <= 18) {
128 *op++ = (t - 3);
129 } else {
130 size_t tt = t - 18;
131 *op++ = 0;
132 while (unlikely(tt > 255)) {
133 tt -= 255;
134 *op++ = 0;
135 }
136 *op++ = tt;
137 }
138 do {
139 COPY8(op, ii);
140 COPY8(op + 8, ii + 8);
141 op += 16;
142 ii += 16;
143 t -= 16;
144 } while (t >= 16);
145 if (t > 0) do {
146 *op++ = *ii++;
147 } while (--t > 0);
148 }
149 }
150
151 if (unlikely(run_length)) {
152 ip += run_length;
153 run_length -= MIN_ZERO_RUN_LENGTH;
154 put_unaligned_le32((run_length << 21) | 0xfffc18
155 | (run_length & 0x7), op);
156 op += 4;
157 run_length = 0;
158 *state_offset = -3;
159 goto finished_writing_instruction;
160 }
161
162 m_len = 4;
163 {
164#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64)
165 u64 v;
166 v = get_unaligned((const u64 *) (ip + m_len)) ^
167 get_unaligned((const u64 *) (m_pos + m_len));
168 if (unlikely(v == 0)) {
169 do {
170 m_len += 8;
171 v = get_unaligned((const u64 *) (ip + m_len)) ^
172 get_unaligned((const u64 *) (m_pos + m_len));
173 if (unlikely(ip + m_len >= ip_end))
174 goto m_len_done;
175 } while (v == 0);
176 }
177# if defined(__LITTLE_ENDIAN)
178 m_len += (unsigned) __builtin_ctzll(v) / 8;
179# elif defined(__BIG_ENDIAN)
180 m_len += (unsigned) __builtin_clzll(v) / 8;
181# else
182# error "missing endian definition"
183# endif
184#elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32)
185 u32 v;
186 v = get_unaligned((const u32 *) (ip + m_len)) ^
187 get_unaligned((const u32 *) (m_pos + m_len));
188 if (unlikely(v == 0)) {
189 do {
190 m_len += 4;
191 v = get_unaligned((const u32 *) (ip + m_len)) ^
192 get_unaligned((const u32 *) (m_pos + m_len));
193 if (v != 0)
194 break;
195 m_len += 4;
196 v = get_unaligned((const u32 *) (ip + m_len)) ^
197 get_unaligned((const u32 *) (m_pos + m_len));
198 if (unlikely(ip + m_len >= ip_end))
199 goto m_len_done;
200 } while (v == 0);
201 }
202# if defined(__LITTLE_ENDIAN)
203 m_len += (unsigned) __builtin_ctz(v) / 8;
204# elif defined(__BIG_ENDIAN)
205 m_len += (unsigned) __builtin_clz(v) / 8;
206# else
207# error "missing endian definition"
208# endif
209#else
210 if (unlikely(ip[m_len] == m_pos[m_len])) {
211 do {
212 m_len += 1;
213 if (ip[m_len] != m_pos[m_len])
214 break;
215 m_len += 1;
216 if (ip[m_len] != m_pos[m_len])
217 break;
218 m_len += 1;
219 if (ip[m_len] != m_pos[m_len])
220 break;
221 m_len += 1;
222 if (ip[m_len] != m_pos[m_len])
223 break;
224 m_len += 1;
225 if (ip[m_len] != m_pos[m_len])
226 break;
227 m_len += 1;
228 if (ip[m_len] != m_pos[m_len])
229 break;
230 m_len += 1;
231 if (ip[m_len] != m_pos[m_len])
232 break;
233 m_len += 1;
234 if (unlikely(ip + m_len >= ip_end))
235 goto m_len_done;
236 } while (ip[m_len] == m_pos[m_len]);
237 }
238#endif
239 }
240m_len_done:
241
242 m_off = ip - m_pos;
243 ip += m_len;
244 if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) {
245 m_off -= 1;
246 *op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2));
247 *op++ = (m_off >> 3);
248 } else if (m_off <= M3_MAX_OFFSET) {
249 m_off -= 1;
250 if (m_len <= M3_MAX_LEN)
251 *op++ = (M3_MARKER | (m_len - 2));
252 else {
253 m_len -= M3_MAX_LEN;
254 *op++ = M3_MARKER | 0;
255 while (unlikely(m_len > 255)) {
256 m_len -= 255;
257 *op++ = 0;
258 }
259 *op++ = (m_len);
260 }
261 *op++ = (m_off << 2);
262 *op++ = (m_off >> 6);
263 } else {
264 m_off -= 0x4000;
265 if (m_len <= M4_MAX_LEN)
266 *op++ = (M4_MARKER | ((m_off >> 11) & 8)
267 | (m_len - 2));
268 else {
269 if (unlikely(((m_off & 0x403f) == 0x403f)
270 && (m_len >= 261)
271 && (m_len <= 264))
272 && likely(bitstream_version)) {
273 // Under lzo-rle, block copies
274 // for 261 <= length <= 264 and
275 // (distance & 0x80f3) == 0x80f3
276 // can result in ambiguous
277 // output. Adjust length
278 // to 260 to prevent ambiguity.
279 ip -= m_len - 260;
280 m_len = 260;
281 }
282 m_len -= M4_MAX_LEN;
283 *op++ = (M4_MARKER | ((m_off >> 11) & 8));
284 while (unlikely(m_len > 255)) {
285 m_len -= 255;
286 *op++ = 0;
287 }
288 *op++ = (m_len);
289 }
290 *op++ = (m_off << 2);
291 *op++ = (m_off >> 6);
292 }
293 *state_offset = -2;
294finished_writing_instruction:
295 ii = ip;
296 goto next;
297 }
298 *out_len = op - out;
299 return in_end - (ii - ti);
300}
301
302static int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len,
303 unsigned char *out, size_t *out_len,
304 void *wrkmem, const unsigned char bitstream_version)
305{
306 const unsigned char *ip = in;
307 unsigned char *op = out;
308 unsigned char *data_start;
309 size_t l = in_len;
310 size_t t = 0;
311 signed char state_offset = -2;
312 unsigned int m4_max_offset;
313
314 // LZO v0 will never write 17 as first byte (except for zero-length
315 // input), so this is used to version the bitstream
316 if (bitstream_version > 0) {
317 *op++ = 17;
318 *op++ = bitstream_version;
319 m4_max_offset = M4_MAX_OFFSET_V1;
320 } else {
321 m4_max_offset = M4_MAX_OFFSET_V0;
322 }
323
324 data_start = op;
325
326 while (l > 20) {
327 size_t ll = min_t(size_t, l, m4_max_offset + 1);
328 uintptr_t ll_end = (uintptr_t) ip + ll;
329 if ((ll_end + ((t + ll) >> 5)) <= ll_end)
330 break;
331 BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS);
332 memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t));
333 t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem,
334 &state_offset, bitstream_version);
335 ip += ll;
336 op += *out_len;
337 l -= ll;
338 }
339 t += l;
340
341 if (t > 0) {
342 const unsigned char *ii = in + in_len - t;
343
344 if (op == data_start && t <= 238) {
345 *op++ = (17 + t);
346 } else if (t <= 3) {
347 op[state_offset] |= t;
348 } else if (t <= 18) {
349 *op++ = (t - 3);
350 } else {
351 size_t tt = t - 18;
352 *op++ = 0;
353 while (tt > 255) {
354 tt -= 255;
355 *op++ = 0;
356 }
357 *op++ = tt;
358 }
359 if (t >= 16) do {
360 COPY8(op, ii);
361 COPY8(op + 8, ii + 8);
362 op += 16;
363 ii += 16;
364 t -= 16;
365 } while (t >= 16);
366 if (t > 0) do {
367 *op++ = *ii++;
368 } while (--t > 0);
369 }
370
371 *op++ = M4_MARKER | 1;
372 *op++ = 0;
373 *op++ = 0;
374
375 *out_len = op - out;
376 return LZO_E_OK;
377}
378
379int lzo1x_1_compress(const unsigned char *in, size_t in_len,
380 unsigned char *out, size_t *out_len,
381 void *wrkmem)
382{
383 return lzogeneric1x_1_compress(in, in_len, out, out_len, wrkmem, 0);
384}
385
386int lzorle1x_1_compress(const unsigned char *in, size_t in_len,
387 unsigned char *out, size_t *out_len,
388 void *wrkmem)
389{
390 return lzogeneric1x_1_compress(in, in_len, out, out_len,
391 wrkmem, LZO_VERSION);
392}
393
394EXPORT_SYMBOL_GPL(lzo1x_1_compress);
395EXPORT_SYMBOL_GPL(lzorle1x_1_compress);
396
397MODULE_LICENSE("GPL");
398MODULE_DESCRIPTION("LZO1X-1 Compressor");