Lasse Collin | 24fa040 | 2011-01-12 17:01:22 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Branch/Call/Jump (BCJ) filter decoders |
| 3 | * |
| 4 | * Authors: Lasse Collin <lasse.collin@tukaani.org> |
| 5 | * Igor Pavlov <http://7-zip.org/> |
| 6 | * |
| 7 | * This file has been put into the public domain. |
| 8 | * You can do whatever you want with this file. |
| 9 | */ |
| 10 | |
| 11 | #include "xz_private.h" |
| 12 | |
| 13 | /* |
| 14 | * The rest of the file is inside this ifdef. It makes things a little more |
| 15 | * convenient when building without support for any BCJ filters. |
| 16 | */ |
| 17 | #ifdef XZ_DEC_BCJ |
| 18 | |
| 19 | struct xz_dec_bcj { |
| 20 | /* Type of the BCJ filter being used */ |
| 21 | enum { |
| 22 | BCJ_X86 = 4, /* x86 or x86-64 */ |
| 23 | BCJ_POWERPC = 5, /* Big endian only */ |
| 24 | BCJ_IA64 = 6, /* Big or little endian */ |
| 25 | BCJ_ARM = 7, /* Little endian only */ |
| 26 | BCJ_ARMTHUMB = 8, /* Little endian only */ |
| 27 | BCJ_SPARC = 9 /* Big or little endian */ |
| 28 | } type; |
| 29 | |
| 30 | /* |
| 31 | * Return value of the next filter in the chain. We need to preserve |
| 32 | * this information across calls, because we must not call the next |
| 33 | * filter anymore once it has returned XZ_STREAM_END. |
| 34 | */ |
| 35 | enum xz_ret ret; |
| 36 | |
| 37 | /* True if we are operating in single-call mode. */ |
| 38 | bool single_call; |
| 39 | |
| 40 | /* |
| 41 | * Absolute position relative to the beginning of the uncompressed |
| 42 | * data (in a single .xz Block). We care only about the lowest 32 |
| 43 | * bits so this doesn't need to be uint64_t even with big files. |
| 44 | */ |
| 45 | uint32_t pos; |
| 46 | |
| 47 | /* x86 filter state */ |
| 48 | uint32_t x86_prev_mask; |
| 49 | |
| 50 | /* Temporary space to hold the variables from struct xz_buf */ |
| 51 | uint8_t *out; |
| 52 | size_t out_pos; |
| 53 | size_t out_size; |
| 54 | |
| 55 | struct { |
| 56 | /* Amount of already filtered data in the beginning of buf */ |
| 57 | size_t filtered; |
| 58 | |
| 59 | /* Total amount of data currently stored in buf */ |
| 60 | size_t size; |
| 61 | |
| 62 | /* |
| 63 | * Buffer to hold a mix of filtered and unfiltered data. This |
| 64 | * needs to be big enough to hold Alignment + 2 * Look-ahead: |
| 65 | * |
| 66 | * Type Alignment Look-ahead |
| 67 | * x86 1 4 |
| 68 | * PowerPC 4 0 |
| 69 | * IA-64 16 0 |
| 70 | * ARM 4 0 |
| 71 | * ARM-Thumb 2 2 |
| 72 | * SPARC 4 0 |
| 73 | */ |
| 74 | uint8_t buf[16]; |
| 75 | } temp; |
| 76 | }; |
| 77 | |
| 78 | #ifdef XZ_DEC_X86 |
| 79 | /* |
| 80 | * This is used to test the most significant byte of a memory address |
| 81 | * in an x86 instruction. |
| 82 | */ |
| 83 | static inline int bcj_x86_test_msbyte(uint8_t b) |
| 84 | { |
| 85 | return b == 0x00 || b == 0xFF; |
| 86 | } |
| 87 | |
| 88 | static size_t bcj_x86(struct xz_dec_bcj *s, uint8_t *buf, size_t size) |
| 89 | { |
| 90 | static const bool mask_to_allowed_status[8] |
| 91 | = { true, true, true, false, true, false, false, false }; |
| 92 | |
| 93 | static const uint8_t mask_to_bit_num[8] = { 0, 1, 2, 2, 3, 3, 3, 3 }; |
| 94 | |
| 95 | size_t i; |
| 96 | size_t prev_pos = (size_t)-1; |
| 97 | uint32_t prev_mask = s->x86_prev_mask; |
| 98 | uint32_t src; |
| 99 | uint32_t dest; |
| 100 | uint32_t j; |
| 101 | uint8_t b; |
| 102 | |
| 103 | if (size <= 4) |
| 104 | return 0; |
| 105 | |
| 106 | size -= 4; |
| 107 | for (i = 0; i < size; ++i) { |
| 108 | if ((buf[i] & 0xFE) != 0xE8) |
| 109 | continue; |
| 110 | |
| 111 | prev_pos = i - prev_pos; |
| 112 | if (prev_pos > 3) { |
| 113 | prev_mask = 0; |
| 114 | } else { |
| 115 | prev_mask = (prev_mask << (prev_pos - 1)) & 7; |
| 116 | if (prev_mask != 0) { |
| 117 | b = buf[i + 4 - mask_to_bit_num[prev_mask]]; |
| 118 | if (!mask_to_allowed_status[prev_mask] |
| 119 | || bcj_x86_test_msbyte(b)) { |
| 120 | prev_pos = i; |
| 121 | prev_mask = (prev_mask << 1) | 1; |
| 122 | continue; |
| 123 | } |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | prev_pos = i; |
| 128 | |
| 129 | if (bcj_x86_test_msbyte(buf[i + 4])) { |
| 130 | src = get_unaligned_le32(buf + i + 1); |
| 131 | while (true) { |
| 132 | dest = src - (s->pos + (uint32_t)i + 5); |
| 133 | if (prev_mask == 0) |
| 134 | break; |
| 135 | |
| 136 | j = mask_to_bit_num[prev_mask] * 8; |
| 137 | b = (uint8_t)(dest >> (24 - j)); |
| 138 | if (!bcj_x86_test_msbyte(b)) |
| 139 | break; |
| 140 | |
| 141 | src = dest ^ (((uint32_t)1 << (32 - j)) - 1); |
| 142 | } |
| 143 | |
| 144 | dest &= 0x01FFFFFF; |
| 145 | dest |= (uint32_t)0 - (dest & 0x01000000); |
| 146 | put_unaligned_le32(dest, buf + i + 1); |
| 147 | i += 4; |
| 148 | } else { |
| 149 | prev_mask = (prev_mask << 1) | 1; |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | prev_pos = i - prev_pos; |
| 154 | s->x86_prev_mask = prev_pos > 3 ? 0 : prev_mask << (prev_pos - 1); |
| 155 | return i; |
| 156 | } |
| 157 | #endif |
| 158 | |
| 159 | #ifdef XZ_DEC_POWERPC |
| 160 | static size_t bcj_powerpc(struct xz_dec_bcj *s, uint8_t *buf, size_t size) |
| 161 | { |
| 162 | size_t i; |
| 163 | uint32_t instr; |
| 164 | |
| 165 | for (i = 0; i + 4 <= size; i += 4) { |
| 166 | instr = get_unaligned_be32(buf + i); |
| 167 | if ((instr & 0xFC000003) == 0x48000001) { |
| 168 | instr &= 0x03FFFFFC; |
| 169 | instr -= s->pos + (uint32_t)i; |
| 170 | instr &= 0x03FFFFFC; |
| 171 | instr |= 0x48000001; |
| 172 | put_unaligned_be32(instr, buf + i); |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | return i; |
| 177 | } |
| 178 | #endif |
| 179 | |
| 180 | #ifdef XZ_DEC_IA64 |
| 181 | static size_t bcj_ia64(struct xz_dec_bcj *s, uint8_t *buf, size_t size) |
| 182 | { |
| 183 | static const uint8_t branch_table[32] = { |
| 184 | 0, 0, 0, 0, 0, 0, 0, 0, |
| 185 | 0, 0, 0, 0, 0, 0, 0, 0, |
| 186 | 4, 4, 6, 6, 0, 0, 7, 7, |
| 187 | 4, 4, 0, 0, 4, 4, 0, 0 |
| 188 | }; |
| 189 | |
| 190 | /* |
| 191 | * The local variables take a little bit stack space, but it's less |
| 192 | * than what LZMA2 decoder takes, so it doesn't make sense to reduce |
| 193 | * stack usage here without doing that for the LZMA2 decoder too. |
| 194 | */ |
| 195 | |
| 196 | /* Loop counters */ |
| 197 | size_t i; |
| 198 | size_t j; |
| 199 | |
| 200 | /* Instruction slot (0, 1, or 2) in the 128-bit instruction word */ |
| 201 | uint32_t slot; |
| 202 | |
| 203 | /* Bitwise offset of the instruction indicated by slot */ |
| 204 | uint32_t bit_pos; |
| 205 | |
| 206 | /* bit_pos split into byte and bit parts */ |
| 207 | uint32_t byte_pos; |
| 208 | uint32_t bit_res; |
| 209 | |
| 210 | /* Address part of an instruction */ |
| 211 | uint32_t addr; |
| 212 | |
| 213 | /* Mask used to detect which instructions to convert */ |
| 214 | uint32_t mask; |
| 215 | |
| 216 | /* 41-bit instruction stored somewhere in the lowest 48 bits */ |
| 217 | uint64_t instr; |
| 218 | |
| 219 | /* Instruction normalized with bit_res for easier manipulation */ |
| 220 | uint64_t norm; |
| 221 | |
| 222 | for (i = 0; i + 16 <= size; i += 16) { |
| 223 | mask = branch_table[buf[i] & 0x1F]; |
| 224 | for (slot = 0, bit_pos = 5; slot < 3; ++slot, bit_pos += 41) { |
| 225 | if (((mask >> slot) & 1) == 0) |
| 226 | continue; |
| 227 | |
| 228 | byte_pos = bit_pos >> 3; |
| 229 | bit_res = bit_pos & 7; |
| 230 | instr = 0; |
| 231 | for (j = 0; j < 6; ++j) |
| 232 | instr |= (uint64_t)(buf[i + j + byte_pos]) |
| 233 | << (8 * j); |
| 234 | |
| 235 | norm = instr >> bit_res; |
| 236 | |
| 237 | if (((norm >> 37) & 0x0F) == 0x05 |
| 238 | && ((norm >> 9) & 0x07) == 0) { |
| 239 | addr = (norm >> 13) & 0x0FFFFF; |
| 240 | addr |= ((uint32_t)(norm >> 36) & 1) << 20; |
| 241 | addr <<= 4; |
| 242 | addr -= s->pos + (uint32_t)i; |
| 243 | addr >>= 4; |
| 244 | |
| 245 | norm &= ~((uint64_t)0x8FFFFF << 13); |
| 246 | norm |= (uint64_t)(addr & 0x0FFFFF) << 13; |
| 247 | norm |= (uint64_t)(addr & 0x100000) |
| 248 | << (36 - 20); |
| 249 | |
| 250 | instr &= (1 << bit_res) - 1; |
| 251 | instr |= norm << bit_res; |
| 252 | |
| 253 | for (j = 0; j < 6; j++) |
| 254 | buf[i + j + byte_pos] |
| 255 | = (uint8_t)(instr >> (8 * j)); |
| 256 | } |
| 257 | } |
| 258 | } |
| 259 | |
| 260 | return i; |
| 261 | } |
| 262 | #endif |
| 263 | |
| 264 | #ifdef XZ_DEC_ARM |
| 265 | static size_t bcj_arm(struct xz_dec_bcj *s, uint8_t *buf, size_t size) |
| 266 | { |
| 267 | size_t i; |
| 268 | uint32_t addr; |
| 269 | |
| 270 | for (i = 0; i + 4 <= size; i += 4) { |
| 271 | if (buf[i + 3] == 0xEB) { |
| 272 | addr = (uint32_t)buf[i] | ((uint32_t)buf[i + 1] << 8) |
| 273 | | ((uint32_t)buf[i + 2] << 16); |
| 274 | addr <<= 2; |
| 275 | addr -= s->pos + (uint32_t)i + 8; |
| 276 | addr >>= 2; |
| 277 | buf[i] = (uint8_t)addr; |
| 278 | buf[i + 1] = (uint8_t)(addr >> 8); |
| 279 | buf[i + 2] = (uint8_t)(addr >> 16); |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | return i; |
| 284 | } |
| 285 | #endif |
| 286 | |
| 287 | #ifdef XZ_DEC_ARMTHUMB |
| 288 | static size_t bcj_armthumb(struct xz_dec_bcj *s, uint8_t *buf, size_t size) |
| 289 | { |
| 290 | size_t i; |
| 291 | uint32_t addr; |
| 292 | |
| 293 | for (i = 0; i + 4 <= size; i += 2) { |
| 294 | if ((buf[i + 1] & 0xF8) == 0xF0 |
| 295 | && (buf[i + 3] & 0xF8) == 0xF8) { |
| 296 | addr = (((uint32_t)buf[i + 1] & 0x07) << 19) |
| 297 | | ((uint32_t)buf[i] << 11) |
| 298 | | (((uint32_t)buf[i + 3] & 0x07) << 8) |
| 299 | | (uint32_t)buf[i + 2]; |
| 300 | addr <<= 1; |
| 301 | addr -= s->pos + (uint32_t)i + 4; |
| 302 | addr >>= 1; |
| 303 | buf[i + 1] = (uint8_t)(0xF0 | ((addr >> 19) & 0x07)); |
| 304 | buf[i] = (uint8_t)(addr >> 11); |
| 305 | buf[i + 3] = (uint8_t)(0xF8 | ((addr >> 8) & 0x07)); |
| 306 | buf[i + 2] = (uint8_t)addr; |
| 307 | i += 2; |
| 308 | } |
| 309 | } |
| 310 | |
| 311 | return i; |
| 312 | } |
| 313 | #endif |
| 314 | |
| 315 | #ifdef XZ_DEC_SPARC |
| 316 | static size_t bcj_sparc(struct xz_dec_bcj *s, uint8_t *buf, size_t size) |
| 317 | { |
| 318 | size_t i; |
| 319 | uint32_t instr; |
| 320 | |
| 321 | for (i = 0; i + 4 <= size; i += 4) { |
| 322 | instr = get_unaligned_be32(buf + i); |
| 323 | if ((instr >> 22) == 0x100 || (instr >> 22) == 0x1FF) { |
| 324 | instr <<= 2; |
| 325 | instr -= s->pos + (uint32_t)i; |
| 326 | instr >>= 2; |
| 327 | instr = ((uint32_t)0x40000000 - (instr & 0x400000)) |
| 328 | | 0x40000000 | (instr & 0x3FFFFF); |
| 329 | put_unaligned_be32(instr, buf + i); |
| 330 | } |
| 331 | } |
| 332 | |
| 333 | return i; |
| 334 | } |
| 335 | #endif |
| 336 | |
| 337 | /* |
| 338 | * Apply the selected BCJ filter. Update *pos and s->pos to match the amount |
| 339 | * of data that got filtered. |
| 340 | * |
| 341 | * NOTE: This is implemented as a switch statement to avoid using function |
| 342 | * pointers, which could be problematic in the kernel boot code, which must |
| 343 | * avoid pointers to static data (at least on x86). |
| 344 | */ |
| 345 | static void bcj_apply(struct xz_dec_bcj *s, |
| 346 | uint8_t *buf, size_t *pos, size_t size) |
| 347 | { |
| 348 | size_t filtered; |
| 349 | |
| 350 | buf += *pos; |
| 351 | size -= *pos; |
| 352 | |
| 353 | switch (s->type) { |
| 354 | #ifdef XZ_DEC_X86 |
| 355 | case BCJ_X86: |
| 356 | filtered = bcj_x86(s, buf, size); |
| 357 | break; |
| 358 | #endif |
| 359 | #ifdef XZ_DEC_POWERPC |
| 360 | case BCJ_POWERPC: |
| 361 | filtered = bcj_powerpc(s, buf, size); |
| 362 | break; |
| 363 | #endif |
| 364 | #ifdef XZ_DEC_IA64 |
| 365 | case BCJ_IA64: |
| 366 | filtered = bcj_ia64(s, buf, size); |
| 367 | break; |
| 368 | #endif |
| 369 | #ifdef XZ_DEC_ARM |
| 370 | case BCJ_ARM: |
| 371 | filtered = bcj_arm(s, buf, size); |
| 372 | break; |
| 373 | #endif |
| 374 | #ifdef XZ_DEC_ARMTHUMB |
| 375 | case BCJ_ARMTHUMB: |
| 376 | filtered = bcj_armthumb(s, buf, size); |
| 377 | break; |
| 378 | #endif |
| 379 | #ifdef XZ_DEC_SPARC |
| 380 | case BCJ_SPARC: |
| 381 | filtered = bcj_sparc(s, buf, size); |
| 382 | break; |
| 383 | #endif |
| 384 | default: |
| 385 | /* Never reached but silence compiler warnings. */ |
| 386 | filtered = 0; |
| 387 | break; |
| 388 | } |
| 389 | |
| 390 | *pos += filtered; |
| 391 | s->pos += filtered; |
| 392 | } |
| 393 | |
| 394 | /* |
| 395 | * Flush pending filtered data from temp to the output buffer. |
| 396 | * Move the remaining mixture of possibly filtered and unfiltered |
| 397 | * data to the beginning of temp. |
| 398 | */ |
| 399 | static void bcj_flush(struct xz_dec_bcj *s, struct xz_buf *b) |
| 400 | { |
| 401 | size_t copy_size; |
| 402 | |
| 403 | copy_size = min_t(size_t, s->temp.filtered, b->out_size - b->out_pos); |
| 404 | memcpy(b->out + b->out_pos, s->temp.buf, copy_size); |
| 405 | b->out_pos += copy_size; |
| 406 | |
| 407 | s->temp.filtered -= copy_size; |
| 408 | s->temp.size -= copy_size; |
| 409 | memmove(s->temp.buf, s->temp.buf + copy_size, s->temp.size); |
| 410 | } |
| 411 | |
| 412 | /* |
| 413 | * The BCJ filter functions are primitive in sense that they process the |
| 414 | * data in chunks of 1-16 bytes. To hide this issue, this function does |
| 415 | * some buffering. |
| 416 | */ |
| 417 | XZ_EXTERN enum xz_ret xz_dec_bcj_run(struct xz_dec_bcj *s, |
| 418 | struct xz_dec_lzma2 *lzma2, |
| 419 | struct xz_buf *b) |
| 420 | { |
| 421 | size_t out_start; |
| 422 | |
| 423 | /* |
| 424 | * Flush pending already filtered data to the output buffer. Return |
| 425 | * immediatelly if we couldn't flush everything, or if the next |
| 426 | * filter in the chain had already returned XZ_STREAM_END. |
| 427 | */ |
| 428 | if (s->temp.filtered > 0) { |
| 429 | bcj_flush(s, b); |
| 430 | if (s->temp.filtered > 0) |
| 431 | return XZ_OK; |
| 432 | |
| 433 | if (s->ret == XZ_STREAM_END) |
| 434 | return XZ_STREAM_END; |
| 435 | } |
| 436 | |
| 437 | /* |
| 438 | * If we have more output space than what is currently pending in |
| 439 | * temp, copy the unfiltered data from temp to the output buffer |
| 440 | * and try to fill the output buffer by decoding more data from the |
| 441 | * next filter in the chain. Apply the BCJ filter on the new data |
| 442 | * in the output buffer. If everything cannot be filtered, copy it |
| 443 | * to temp and rewind the output buffer position accordingly. |
Lasse Collin | 9c1f859 | 2011-09-21 17:30:50 +0300 | [diff] [blame^] | 444 | * |
| 445 | * This needs to be always run when temp.size == 0 to handle a special |
| 446 | * case where the output buffer is full and the next filter has no |
| 447 | * more output coming but hasn't returned XZ_STREAM_END yet. |
Lasse Collin | 24fa040 | 2011-01-12 17:01:22 -0800 | [diff] [blame] | 448 | */ |
Lasse Collin | 9c1f859 | 2011-09-21 17:30:50 +0300 | [diff] [blame^] | 449 | if (s->temp.size < b->out_size - b->out_pos || s->temp.size == 0) { |
Lasse Collin | 24fa040 | 2011-01-12 17:01:22 -0800 | [diff] [blame] | 450 | out_start = b->out_pos; |
| 451 | memcpy(b->out + b->out_pos, s->temp.buf, s->temp.size); |
| 452 | b->out_pos += s->temp.size; |
| 453 | |
| 454 | s->ret = xz_dec_lzma2_run(lzma2, b); |
| 455 | if (s->ret != XZ_STREAM_END |
| 456 | && (s->ret != XZ_OK || s->single_call)) |
| 457 | return s->ret; |
| 458 | |
| 459 | bcj_apply(s, b->out, &out_start, b->out_pos); |
| 460 | |
| 461 | /* |
| 462 | * As an exception, if the next filter returned XZ_STREAM_END, |
| 463 | * we can do that too, since the last few bytes that remain |
| 464 | * unfiltered are meant to remain unfiltered. |
| 465 | */ |
| 466 | if (s->ret == XZ_STREAM_END) |
| 467 | return XZ_STREAM_END; |
| 468 | |
| 469 | s->temp.size = b->out_pos - out_start; |
| 470 | b->out_pos -= s->temp.size; |
| 471 | memcpy(s->temp.buf, b->out + b->out_pos, s->temp.size); |
Lasse Collin | 9c1f859 | 2011-09-21 17:30:50 +0300 | [diff] [blame^] | 472 | |
| 473 | /* |
| 474 | * If there wasn't enough input to the next filter to fill |
| 475 | * the output buffer with unfiltered data, there's no point |
| 476 | * to try decoding more data to temp. |
| 477 | */ |
| 478 | if (b->out_pos + s->temp.size < b->out_size) |
| 479 | return XZ_OK; |
Lasse Collin | 24fa040 | 2011-01-12 17:01:22 -0800 | [diff] [blame] | 480 | } |
| 481 | |
| 482 | /* |
Lasse Collin | 9c1f859 | 2011-09-21 17:30:50 +0300 | [diff] [blame^] | 483 | * We have unfiltered data in temp. If the output buffer isn't full |
| 484 | * yet, try to fill the temp buffer by decoding more data from the |
| 485 | * next filter. Apply the BCJ filter on temp. Then we hopefully can |
| 486 | * fill the actual output buffer by copying filtered data from temp. |
| 487 | * A mix of filtered and unfiltered data may be left in temp; it will |
| 488 | * be taken care on the next call to this function. |
Lasse Collin | 24fa040 | 2011-01-12 17:01:22 -0800 | [diff] [blame] | 489 | */ |
Lasse Collin | 9c1f859 | 2011-09-21 17:30:50 +0300 | [diff] [blame^] | 490 | if (b->out_pos < b->out_size) { |
Lasse Collin | 24fa040 | 2011-01-12 17:01:22 -0800 | [diff] [blame] | 491 | /* Make b->out{,_pos,_size} temporarily point to s->temp. */ |
| 492 | s->out = b->out; |
| 493 | s->out_pos = b->out_pos; |
| 494 | s->out_size = b->out_size; |
| 495 | b->out = s->temp.buf; |
| 496 | b->out_pos = s->temp.size; |
| 497 | b->out_size = sizeof(s->temp.buf); |
| 498 | |
| 499 | s->ret = xz_dec_lzma2_run(lzma2, b); |
| 500 | |
| 501 | s->temp.size = b->out_pos; |
| 502 | b->out = s->out; |
| 503 | b->out_pos = s->out_pos; |
| 504 | b->out_size = s->out_size; |
| 505 | |
| 506 | if (s->ret != XZ_OK && s->ret != XZ_STREAM_END) |
| 507 | return s->ret; |
| 508 | |
| 509 | bcj_apply(s, s->temp.buf, &s->temp.filtered, s->temp.size); |
| 510 | |
| 511 | /* |
| 512 | * If the next filter returned XZ_STREAM_END, we mark that |
| 513 | * everything is filtered, since the last unfiltered bytes |
| 514 | * of the stream are meant to be left as is. |
| 515 | */ |
| 516 | if (s->ret == XZ_STREAM_END) |
| 517 | s->temp.filtered = s->temp.size; |
| 518 | |
| 519 | bcj_flush(s, b); |
| 520 | if (s->temp.filtered > 0) |
| 521 | return XZ_OK; |
| 522 | } |
| 523 | |
| 524 | return s->ret; |
| 525 | } |
| 526 | |
| 527 | XZ_EXTERN struct xz_dec_bcj *xz_dec_bcj_create(bool single_call) |
| 528 | { |
| 529 | struct xz_dec_bcj *s = kmalloc(sizeof(*s), GFP_KERNEL); |
| 530 | if (s != NULL) |
| 531 | s->single_call = single_call; |
| 532 | |
| 533 | return s; |
| 534 | } |
| 535 | |
| 536 | XZ_EXTERN enum xz_ret xz_dec_bcj_reset(struct xz_dec_bcj *s, uint8_t id) |
| 537 | { |
| 538 | switch (id) { |
| 539 | #ifdef XZ_DEC_X86 |
| 540 | case BCJ_X86: |
| 541 | #endif |
| 542 | #ifdef XZ_DEC_POWERPC |
| 543 | case BCJ_POWERPC: |
| 544 | #endif |
| 545 | #ifdef XZ_DEC_IA64 |
| 546 | case BCJ_IA64: |
| 547 | #endif |
| 548 | #ifdef XZ_DEC_ARM |
| 549 | case BCJ_ARM: |
| 550 | #endif |
| 551 | #ifdef XZ_DEC_ARMTHUMB |
| 552 | case BCJ_ARMTHUMB: |
| 553 | #endif |
| 554 | #ifdef XZ_DEC_SPARC |
| 555 | case BCJ_SPARC: |
| 556 | #endif |
| 557 | break; |
| 558 | |
| 559 | default: |
| 560 | /* Unsupported Filter ID */ |
| 561 | return XZ_OPTIONS_ERROR; |
| 562 | } |
| 563 | |
| 564 | s->type = id; |
| 565 | s->ret = XZ_OK; |
| 566 | s->pos = 0; |
| 567 | s->x86_prev_mask = 0; |
| 568 | s->temp.filtered = 0; |
| 569 | s->temp.size = 0; |
| 570 | |
| 571 | return XZ_OK; |
| 572 | } |
| 573 | |
| 574 | #endif |