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 <asm/unaligned.h> 18 #include <linux/lzo.h> 19 #include "lzodefs.h" 20 21 static noinline size_t 22 lzo1x_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; 44 literal: 45 ip += 1 + ((ip - ii) >> 5); 46 next: 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 = ip_end 54 < (ip + MAX_ZERO_RUN_LENGTH + 1) 55 ? ip_end : ip + MAX_ZERO_RUN_LENGTH + 1; 56 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \ 57 defined(LZO_FAST_64BIT_MEMORY_ACCESS) 58 u64 dv64; 59 60 for (; (ir + 32) <= limit; ir += 32) { 61 dv64 = get_unaligned((u64 *)ir); 62 dv64 |= get_unaligned((u64 *)ir + 1); 63 dv64 |= get_unaligned((u64 *)ir + 2); 64 dv64 |= get_unaligned((u64 *)ir + 3); 65 if (dv64) 66 break; 67 } 68 for (; (ir + 8) <= limit; ir += 8) { 69 dv64 = get_unaligned((u64 *)ir); 70 if (dv64) { 71 # if defined(__LITTLE_ENDIAN) 72 ir += __builtin_ctzll(dv64) >> 3; 73 # elif defined(__BIG_ENDIAN) 74 ir += __builtin_clzll(dv64) >> 3; 75 # else 76 # error "missing endian definition" 77 # endif 78 break; 79 } 80 } 81 #else 82 while ((ir < (const unsigned char *) 83 ALIGN((uintptr_t)ir, 4)) && 84 (ir < limit) && (*ir == 0)) 85 ir++; 86 for (; (ir + 4) <= limit; ir += 4) { 87 dv = *((u32 *)ir); 88 if (dv) { 89 # if defined(__LITTLE_ENDIAN) 90 ir += __builtin_ctz(dv) >> 3; 91 # elif defined(__BIG_ENDIAN) 92 ir += __builtin_clz(dv) >> 3; 93 # else 94 # error "missing endian definition" 95 # endif 96 break; 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 } 240 m_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 m_len -= M4_MAX_LEN; 270 *op++ = (M4_MARKER | ((m_off >> 11) & 8)); 271 while (unlikely(m_len > 255)) { 272 m_len -= 255; 273 *op++ = 0; 274 } 275 *op++ = (m_len); 276 } 277 *op++ = (m_off << 2); 278 *op++ = (m_off >> 6); 279 } 280 *state_offset = -2; 281 finished_writing_instruction: 282 ii = ip; 283 goto next; 284 } 285 *out_len = op - out; 286 return in_end - (ii - ti); 287 } 288 289 int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len, 290 unsigned char *out, size_t *out_len, 291 void *wrkmem, const unsigned char bitstream_version) 292 { 293 const unsigned char *ip = in; 294 unsigned char *op = out; 295 unsigned char *data_start; 296 size_t l = in_len; 297 size_t t = 0; 298 signed char state_offset = -2; 299 unsigned int m4_max_offset; 300 301 // LZO v0 will never write 17 as first byte (except for zero-length 302 // input), so this is used to version the bitstream 303 if (bitstream_version > 0) { 304 *op++ = 17; 305 *op++ = bitstream_version; 306 m4_max_offset = M4_MAX_OFFSET_V1; 307 } else { 308 m4_max_offset = M4_MAX_OFFSET_V0; 309 } 310 311 data_start = op; 312 313 while (l > 20) { 314 size_t ll = l <= (m4_max_offset + 1) ? l : (m4_max_offset + 1); 315 uintptr_t ll_end = (uintptr_t) ip + ll; 316 if ((ll_end + ((t + ll) >> 5)) <= ll_end) 317 break; 318 BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS); 319 memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t)); 320 t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem, 321 &state_offset, bitstream_version); 322 ip += ll; 323 op += *out_len; 324 l -= ll; 325 } 326 t += l; 327 328 if (t > 0) { 329 const unsigned char *ii = in + in_len - t; 330 331 if (op == data_start && t <= 238) { 332 *op++ = (17 + t); 333 } else if (t <= 3) { 334 op[state_offset] |= t; 335 } else if (t <= 18) { 336 *op++ = (t - 3); 337 } else { 338 size_t tt = t - 18; 339 *op++ = 0; 340 while (tt > 255) { 341 tt -= 255; 342 *op++ = 0; 343 } 344 *op++ = tt; 345 } 346 if (t >= 16) do { 347 COPY8(op, ii); 348 COPY8(op + 8, ii + 8); 349 op += 16; 350 ii += 16; 351 t -= 16; 352 } while (t >= 16); 353 if (t > 0) do { 354 *op++ = *ii++; 355 } while (--t > 0); 356 } 357 358 *op++ = M4_MARKER | 1; 359 *op++ = 0; 360 *op++ = 0; 361 362 *out_len = op - out; 363 return LZO_E_OK; 364 } 365 366 int lzo1x_1_compress(const unsigned char *in, size_t in_len, 367 unsigned char *out, size_t *out_len, 368 void *wrkmem) 369 { 370 return lzogeneric1x_1_compress(in, in_len, out, out_len, wrkmem, 0); 371 } 372 373 int lzorle1x_1_compress(const unsigned char *in, size_t in_len, 374 unsigned char *out, size_t *out_len, 375 void *wrkmem) 376 { 377 return lzogeneric1x_1_compress(in, in_len, out, out_len, 378 wrkmem, LZO_VERSION); 379 } 380 381 EXPORT_SYMBOL_GPL(lzo1x_1_compress); 382 EXPORT_SYMBOL_GPL(lzorle1x_1_compress); 383 384 MODULE_LICENSE("GPL"); 385 MODULE_DESCRIPTION("LZO1X-1 Compressor"); 386