| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd |
| * |
| * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com> |
| */ |
| |
| #ifdef STATIC |
| #define PREBOOT |
| #include "lz4/lz4_decompress.c" |
| #else |
| #include <linux/decompress/unlz4.h> |
| #endif |
| #include <linux/types.h> |
| #include <linux/lz4.h> |
| #include <linux/decompress/mm.h> |
| #include <linux/compiler.h> |
| |
| #include <linux/unaligned.h> |
| |
| /* |
| * Note: Uncompressed chunk size is used in the compressor side |
| * (userspace side for compression). |
| * It is hardcoded because there is not proper way to extract it |
| * from the binary stream which is generated by the preliminary |
| * version of LZ4 tool so far. |
| */ |
| #define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20) |
| #define ARCHIVE_MAGICNUMBER 0x184C2102 |
| |
| STATIC inline int INIT unlz4(u8 *input, long in_len, |
| long (*fill)(void *, unsigned long), |
| long (*flush)(void *, unsigned long), |
| u8 *output, long *posp, |
| void (*error) (char *x)) |
| { |
| int ret = -1; |
| size_t chunksize = 0; |
| size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE; |
| u8 *inp; |
| u8 *inp_start; |
| u8 *outp; |
| long size = in_len; |
| #ifdef PREBOOT |
| size_t out_len = get_unaligned_le32(input + in_len); |
| #endif |
| size_t dest_len; |
| |
| |
| if (output) { |
| outp = output; |
| } else if (!flush) { |
| error("NULL output pointer and no flush function provided"); |
| goto exit_0; |
| } else { |
| outp = large_malloc(uncomp_chunksize); |
| if (!outp) { |
| error("Could not allocate output buffer"); |
| goto exit_0; |
| } |
| } |
| |
| if (input && fill) { |
| error("Both input pointer and fill function provided,"); |
| goto exit_1; |
| } else if (input) { |
| inp = input; |
| } else if (!fill) { |
| error("NULL input pointer and missing fill function"); |
| goto exit_1; |
| } else { |
| inp = large_malloc(LZ4_compressBound(uncomp_chunksize)); |
| if (!inp) { |
| error("Could not allocate input buffer"); |
| goto exit_1; |
| } |
| } |
| inp_start = inp; |
| |
| if (posp) |
| *posp = 0; |
| |
| if (fill) { |
| size = fill(inp, 4); |
| if (size < 4) { |
| error("data corrupted"); |
| goto exit_2; |
| } |
| } |
| |
| chunksize = get_unaligned_le32(inp); |
| if (chunksize == ARCHIVE_MAGICNUMBER) { |
| if (!fill) { |
| inp += 4; |
| size -= 4; |
| } |
| } else { |
| error("invalid header"); |
| goto exit_2; |
| } |
| |
| if (posp) |
| *posp += 4; |
| |
| for (;;) { |
| |
| if (fill) { |
| size = fill(inp, 4); |
| if (size == 0) |
| break; |
| if (size < 4) { |
| error("data corrupted"); |
| goto exit_2; |
| } |
| } else if (size < 4) { |
| /* empty or end-of-file */ |
| goto exit_3; |
| } |
| |
| chunksize = get_unaligned_le32(inp); |
| if (chunksize == ARCHIVE_MAGICNUMBER) { |
| if (!fill) { |
| inp += 4; |
| size -= 4; |
| } |
| if (posp) |
| *posp += 4; |
| continue; |
| } |
| |
| if (!fill && chunksize == 0) { |
| /* empty or end-of-file */ |
| goto exit_3; |
| } |
| |
| if (posp) |
| *posp += 4; |
| |
| if (!fill) { |
| inp += 4; |
| size -= 4; |
| } else { |
| if (chunksize > LZ4_compressBound(uncomp_chunksize)) { |
| error("chunk length is longer than allocated"); |
| goto exit_2; |
| } |
| size = fill(inp, chunksize); |
| if (size < chunksize) { |
| error("data corrupted"); |
| goto exit_2; |
| } |
| } |
| #ifdef PREBOOT |
| if (out_len >= uncomp_chunksize) { |
| dest_len = uncomp_chunksize; |
| out_len -= dest_len; |
| } else |
| dest_len = out_len; |
| |
| ret = LZ4_decompress_fast(inp, outp, dest_len); |
| chunksize = ret; |
| #else |
| dest_len = uncomp_chunksize; |
| |
| ret = LZ4_decompress_safe(inp, outp, chunksize, dest_len); |
| dest_len = ret; |
| #endif |
| if (ret < 0) { |
| error("Decoding failed"); |
| goto exit_2; |
| } |
| |
| ret = -1; |
| if (flush && flush(outp, dest_len) != dest_len) |
| goto exit_2; |
| if (output) |
| outp += dest_len; |
| if (posp) |
| *posp += chunksize; |
| |
| if (!fill) { |
| size -= chunksize; |
| |
| if (size == 0) |
| break; |
| else if (size < 0) { |
| error("data corrupted"); |
| goto exit_2; |
| } |
| inp += chunksize; |
| } |
| } |
| |
| exit_3: |
| ret = 0; |
| exit_2: |
| if (!input) |
| large_free(inp_start); |
| exit_1: |
| if (!output) |
| large_free(outp); |
| exit_0: |
| return ret; |
| } |
| |
| #ifdef PREBOOT |
| STATIC int INIT __decompress(unsigned char *buf, long in_len, |
| long (*fill)(void*, unsigned long), |
| long (*flush)(void*, unsigned long), |
| unsigned char *output, long out_len, |
| long *posp, |
| void (*error)(char *x) |
| ) |
| { |
| return unlz4(buf, in_len - 4, fill, flush, output, posp, error); |
| } |
| #endif |