| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * erofs-utils/lib/decompress.c |
| * |
| * Copyright (C), 2008-2020, OPPO Mobile Comm Corp., Ltd. |
| * Created by Huang Jianan <huangjianan@oppo.com> |
| */ |
| #include <stdlib.h> |
| |
| #include "erofs/decompress.h" |
| #include "erofs/err.h" |
| |
| #ifdef LZ4_ENABLED |
| #include <lz4.h> |
| |
| static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq) |
| { |
| int ret = 0; |
| char *dest = rq->out; |
| char *src = rq->in; |
| char *buff = NULL; |
| bool support_0padding = false; |
| unsigned int inputmargin = 0; |
| |
| if (erofs_sb_has_lz4_0padding()) { |
| support_0padding = true; |
| |
| while (!src[inputmargin & ~PAGE_MASK]) |
| if (!(++inputmargin & ~PAGE_MASK)) |
| break; |
| |
| if (inputmargin >= rq->inputsize) |
| return -EIO; |
| } |
| |
| if (rq->decodedskip) { |
| buff = malloc(rq->decodedlength); |
| if (!buff) |
| return -ENOMEM; |
| dest = buff; |
| } |
| |
| if (rq->partial_decoding || !support_0padding) |
| ret = LZ4_decompress_safe_partial(src + inputmargin, dest, |
| rq->inputsize - inputmargin, |
| rq->decodedlength, rq->decodedlength); |
| else |
| ret = LZ4_decompress_safe(src + inputmargin, dest, |
| rq->inputsize - inputmargin, |
| rq->decodedlength); |
| |
| if (ret != (int)rq->decodedlength) { |
| ret = -EIO; |
| goto out; |
| } |
| |
| if (rq->decodedskip) |
| memcpy(rq->out, dest + rq->decodedskip, |
| rq->decodedlength - rq->decodedskip); |
| |
| out: |
| if (buff) |
| free(buff); |
| |
| return ret; |
| } |
| #endif |
| |
| int z_erofs_decompress(struct z_erofs_decompress_req *rq) |
| { |
| if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED) { |
| if (rq->inputsize != EROFS_BLKSIZ) |
| return -EFSCORRUPTED; |
| |
| DBG_BUGON(rq->decodedlength > EROFS_BLKSIZ); |
| DBG_BUGON(rq->decodedlength < rq->decodedskip); |
| |
| memcpy(rq->out, rq->in + rq->decodedskip, |
| rq->decodedlength - rq->decodedskip); |
| return 0; |
| } |
| |
| #ifdef LZ4_ENABLED |
| if (rq->alg == Z_EROFS_COMPRESSION_LZ4) |
| return z_erofs_decompress_lz4(rq); |
| #endif |
| return -EOPNOTSUPP; |
| } |