| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * LZO1X Compressor from LZO |
| * |
| * Copyright (C) 1996-2012 Markus F.X.J. Oberhumer <markus@oberhumer.com> |
| * |
| * The full LZO package can be found at: |
| * http://www.oberhumer.com/opensource/lzo/ |
| * |
| * Changed for Linux kernel use by: |
| * Nitin Gupta <nitingupta910@gmail.com> |
| * Richard Purdie <rpurdie@openedhand.com> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <asm/unaligned.h> |
| #include <linux/lzo.h> |
| #include "lzodefs.h" |
| |
| static noinline size_t |
| lzo1x_1_do_compress(const unsigned char *in, size_t in_len, |
| unsigned char *out, size_t *out_len, |
| size_t ti, void *wrkmem, signed char *state_offset, |
| const unsigned char bitstream_version) |
| { |
| const unsigned char *ip; |
| unsigned char *op; |
| const unsigned char * const in_end = in + in_len; |
| const unsigned char * const ip_end = in + in_len - 20; |
| const unsigned char *ii; |
| lzo_dict_t * const dict = (lzo_dict_t *) wrkmem; |
| |
| op = out; |
| ip = in; |
| ii = ip; |
| ip += ti < 4 ? 4 - ti : 0; |
| |
| for (;;) { |
| const unsigned char *m_pos = NULL; |
| size_t t, m_len, m_off; |
| u32 dv; |
| u32 run_length = 0; |
| literal: |
| ip += 1 + ((ip - ii) >> 5); |
| next: |
| if (unlikely(ip >= ip_end)) |
| break; |
| dv = get_unaligned_le32(ip); |
| |
| if (dv == 0 && bitstream_version) { |
| const unsigned char *ir = ip + 4; |
| const unsigned char *limit = ip_end |
| < (ip + MAX_ZERO_RUN_LENGTH + 1) |
| ? ip_end : ip + MAX_ZERO_RUN_LENGTH + 1; |
| #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && \ |
| defined(LZO_FAST_64BIT_MEMORY_ACCESS) |
| u64 dv64; |
| |
| for (; (ir + 32) <= limit; ir += 32) { |
| dv64 = get_unaligned((u64 *)ir); |
| dv64 |= get_unaligned((u64 *)ir + 1); |
| dv64 |= get_unaligned((u64 *)ir + 2); |
| dv64 |= get_unaligned((u64 *)ir + 3); |
| if (dv64) |
| break; |
| } |
| for (; (ir + 8) <= limit; ir += 8) { |
| dv64 = get_unaligned((u64 *)ir); |
| if (dv64) { |
| # if defined(__LITTLE_ENDIAN) |
| ir += __builtin_ctzll(dv64) >> 3; |
| # elif defined(__BIG_ENDIAN) |
| ir += __builtin_clzll(dv64) >> 3; |
| # else |
| # error "missing endian definition" |
| # endif |
| break; |
| } |
| } |
| #else |
| while ((ir < (const unsigned char *) |
| ALIGN((uintptr_t)ir, 4)) && |
| (ir < limit) && (*ir == 0)) |
| ir++; |
| for (; (ir + 4) <= limit; ir += 4) { |
| dv = *((u32 *)ir); |
| if (dv) { |
| # if defined(__LITTLE_ENDIAN) |
| ir += __builtin_ctz(dv) >> 3; |
| # elif defined(__BIG_ENDIAN) |
| ir += __builtin_clz(dv) >> 3; |
| # else |
| # error "missing endian definition" |
| # endif |
| break; |
| } |
| } |
| #endif |
| while (likely(ir < limit) && unlikely(*ir == 0)) |
| ir++; |
| run_length = ir - ip; |
| if (run_length > MAX_ZERO_RUN_LENGTH) |
| run_length = MAX_ZERO_RUN_LENGTH; |
| } else { |
| t = ((dv * 0x1824429d) >> (32 - D_BITS)) & D_MASK; |
| m_pos = in + dict[t]; |
| dict[t] = (lzo_dict_t) (ip - in); |
| if (unlikely(dv != get_unaligned_le32(m_pos))) |
| goto literal; |
| } |
| |
| ii -= ti; |
| ti = 0; |
| t = ip - ii; |
| if (t != 0) { |
| if (t <= 3) { |
| op[*state_offset] |= t; |
| COPY4(op, ii); |
| op += t; |
| } else if (t <= 16) { |
| *op++ = (t - 3); |
| COPY8(op, ii); |
| COPY8(op + 8, ii + 8); |
| op += t; |
| } else { |
| if (t <= 18) { |
| *op++ = (t - 3); |
| } else { |
| size_t tt = t - 18; |
| *op++ = 0; |
| while (unlikely(tt > 255)) { |
| tt -= 255; |
| *op++ = 0; |
| } |
| *op++ = tt; |
| } |
| do { |
| COPY8(op, ii); |
| COPY8(op + 8, ii + 8); |
| op += 16; |
| ii += 16; |
| t -= 16; |
| } while (t >= 16); |
| if (t > 0) do { |
| *op++ = *ii++; |
| } while (--t > 0); |
| } |
| } |
| |
| if (unlikely(run_length)) { |
| ip += run_length; |
| run_length -= MIN_ZERO_RUN_LENGTH; |
| put_unaligned_le32((run_length << 21) | 0xfffc18 |
| | (run_length & 0x7), op); |
| op += 4; |
| run_length = 0; |
| *state_offset = -3; |
| goto finished_writing_instruction; |
| } |
| |
| m_len = 4; |
| { |
| #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ64) |
| u64 v; |
| v = get_unaligned((const u64 *) (ip + m_len)) ^ |
| get_unaligned((const u64 *) (m_pos + m_len)); |
| if (unlikely(v == 0)) { |
| do { |
| m_len += 8; |
| v = get_unaligned((const u64 *) (ip + m_len)) ^ |
| get_unaligned((const u64 *) (m_pos + m_len)); |
| if (unlikely(ip + m_len >= ip_end)) |
| goto m_len_done; |
| } while (v == 0); |
| } |
| # if defined(__LITTLE_ENDIAN) |
| m_len += (unsigned) __builtin_ctzll(v) / 8; |
| # elif defined(__BIG_ENDIAN) |
| m_len += (unsigned) __builtin_clzll(v) / 8; |
| # else |
| # error "missing endian definition" |
| # endif |
| #elif defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && defined(LZO_USE_CTZ32) |
| u32 v; |
| v = get_unaligned((const u32 *) (ip + m_len)) ^ |
| get_unaligned((const u32 *) (m_pos + m_len)); |
| if (unlikely(v == 0)) { |
| do { |
| m_len += 4; |
| v = get_unaligned((const u32 *) (ip + m_len)) ^ |
| get_unaligned((const u32 *) (m_pos + m_len)); |
| if (v != 0) |
| break; |
| m_len += 4; |
| v = get_unaligned((const u32 *) (ip + m_len)) ^ |
| get_unaligned((const u32 *) (m_pos + m_len)); |
| if (unlikely(ip + m_len >= ip_end)) |
| goto m_len_done; |
| } while (v == 0); |
| } |
| # if defined(__LITTLE_ENDIAN) |
| m_len += (unsigned) __builtin_ctz(v) / 8; |
| # elif defined(__BIG_ENDIAN) |
| m_len += (unsigned) __builtin_clz(v) / 8; |
| # else |
| # error "missing endian definition" |
| # endif |
| #else |
| if (unlikely(ip[m_len] == m_pos[m_len])) { |
| do { |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (ip[m_len] != m_pos[m_len]) |
| break; |
| m_len += 1; |
| if (unlikely(ip + m_len >= ip_end)) |
| goto m_len_done; |
| } while (ip[m_len] == m_pos[m_len]); |
| } |
| #endif |
| } |
| m_len_done: |
| |
| m_off = ip - m_pos; |
| ip += m_len; |
| if (m_len <= M2_MAX_LEN && m_off <= M2_MAX_OFFSET) { |
| m_off -= 1; |
| *op++ = (((m_len - 1) << 5) | ((m_off & 7) << 2)); |
| *op++ = (m_off >> 3); |
| } else if (m_off <= M3_MAX_OFFSET) { |
| m_off -= 1; |
| if (m_len <= M3_MAX_LEN) |
| *op++ = (M3_MARKER | (m_len - 2)); |
| else { |
| m_len -= M3_MAX_LEN; |
| *op++ = M3_MARKER | 0; |
| while (unlikely(m_len > 255)) { |
| m_len -= 255; |
| *op++ = 0; |
| } |
| *op++ = (m_len); |
| } |
| *op++ = (m_off << 2); |
| *op++ = (m_off >> 6); |
| } else { |
| m_off -= 0x4000; |
| if (m_len <= M4_MAX_LEN) |
| *op++ = (M4_MARKER | ((m_off >> 11) & 8) |
| | (m_len - 2)); |
| else { |
| m_len -= M4_MAX_LEN; |
| *op++ = (M4_MARKER | ((m_off >> 11) & 8)); |
| while (unlikely(m_len > 255)) { |
| m_len -= 255; |
| *op++ = 0; |
| } |
| *op++ = (m_len); |
| } |
| *op++ = (m_off << 2); |
| *op++ = (m_off >> 6); |
| } |
| *state_offset = -2; |
| finished_writing_instruction: |
| ii = ip; |
| goto next; |
| } |
| *out_len = op - out; |
| return in_end - (ii - ti); |
| } |
| |
| int lzogeneric1x_1_compress(const unsigned char *in, size_t in_len, |
| unsigned char *out, size_t *out_len, |
| void *wrkmem, const unsigned char bitstream_version) |
| { |
| const unsigned char *ip = in; |
| unsigned char *op = out; |
| unsigned char *data_start; |
| size_t l = in_len; |
| size_t t = 0; |
| signed char state_offset = -2; |
| unsigned int m4_max_offset; |
| |
| // LZO v0 will never write 17 as first byte (except for zero-length |
| // input), so this is used to version the bitstream |
| if (bitstream_version > 0) { |
| *op++ = 17; |
| *op++ = bitstream_version; |
| m4_max_offset = M4_MAX_OFFSET_V1; |
| } else { |
| m4_max_offset = M4_MAX_OFFSET_V0; |
| } |
| |
| data_start = op; |
| |
| while (l > 20) { |
| size_t ll = l <= (m4_max_offset + 1) ? l : (m4_max_offset + 1); |
| uintptr_t ll_end = (uintptr_t) ip + ll; |
| if ((ll_end + ((t + ll) >> 5)) <= ll_end) |
| break; |
| BUILD_BUG_ON(D_SIZE * sizeof(lzo_dict_t) > LZO1X_1_MEM_COMPRESS); |
| memset(wrkmem, 0, D_SIZE * sizeof(lzo_dict_t)); |
| t = lzo1x_1_do_compress(ip, ll, op, out_len, t, wrkmem, |
| &state_offset, bitstream_version); |
| ip += ll; |
| op += *out_len; |
| l -= ll; |
| } |
| t += l; |
| |
| if (t > 0) { |
| const unsigned char *ii = in + in_len - t; |
| |
| if (op == data_start && t <= 238) { |
| *op++ = (17 + t); |
| } else if (t <= 3) { |
| op[state_offset] |= t; |
| } else if (t <= 18) { |
| *op++ = (t - 3); |
| } else { |
| size_t tt = t - 18; |
| *op++ = 0; |
| while (tt > 255) { |
| tt -= 255; |
| *op++ = 0; |
| } |
| *op++ = tt; |
| } |
| if (t >= 16) do { |
| COPY8(op, ii); |
| COPY8(op + 8, ii + 8); |
| op += 16; |
| ii += 16; |
| t -= 16; |
| } while (t >= 16); |
| if (t > 0) do { |
| *op++ = *ii++; |
| } while (--t > 0); |
| } |
| |
| *op++ = M4_MARKER | 1; |
| *op++ = 0; |
| *op++ = 0; |
| |
| *out_len = op - out; |
| return LZO_E_OK; |
| } |
| |
| int lzo1x_1_compress(const unsigned char *in, size_t in_len, |
| unsigned char *out, size_t *out_len, |
| void *wrkmem) |
| { |
| return lzogeneric1x_1_compress(in, in_len, out, out_len, wrkmem, 0); |
| } |
| |
| int lzorle1x_1_compress(const unsigned char *in, size_t in_len, |
| unsigned char *out, size_t *out_len, |
| void *wrkmem) |
| { |
| return lzogeneric1x_1_compress(in, in_len, out, out_len, |
| wrkmem, LZO_VERSION); |
| } |
| |
| EXPORT_SYMBOL_GPL(lzo1x_1_compress); |
| EXPORT_SYMBOL_GPL(lzorle1x_1_compress); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("LZO1X-1 Compressor"); |