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80 lines
1.8 KiB
80 lines
1.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* uncompress.c |
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* |
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* (C) Copyright 1999 Linus Torvalds |
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* |
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* cramfs interfaces to the uncompression library. There's really just |
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* three entrypoints: |
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* |
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* - cramfs_uncompress_init() - called to initialize the thing. |
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* - cramfs_uncompress_exit() - tell me when you're done |
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* - cramfs_uncompress_block() - uncompress a block. |
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* |
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* NOTE NOTE NOTE! The uncompression is entirely single-threaded. We |
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* only have one stream, and we'll initialize it only once even if it |
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* then is used by multiple filesystems. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/kernel.h> |
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#include <linux/errno.h> |
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#include <linux/vmalloc.h> |
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#include <linux/zlib.h> |
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#include "internal.h" |
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static z_stream stream; |
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static int initialized; |
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/* Returns length of decompressed data. */ |
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int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen) |
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{ |
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int err; |
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stream.next_in = src; |
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stream.avail_in = srclen; |
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stream.next_out = dst; |
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stream.avail_out = dstlen; |
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err = zlib_inflateReset(&stream); |
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if (err != Z_OK) { |
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pr_err("zlib_inflateReset error %d\n", err); |
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zlib_inflateEnd(&stream); |
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zlib_inflateInit(&stream); |
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} |
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err = zlib_inflate(&stream, Z_FINISH); |
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if (err != Z_STREAM_END) |
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goto err; |
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return stream.total_out; |
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err: |
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pr_err("Error %d while decompressing!\n", err); |
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pr_err("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen); |
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return -EIO; |
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} |
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int cramfs_uncompress_init(void) |
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{ |
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if (!initialized++) { |
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stream.workspace = vmalloc(zlib_inflate_workspacesize()); |
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if (!stream.workspace) { |
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initialized = 0; |
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return -ENOMEM; |
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} |
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stream.next_in = NULL; |
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stream.avail_in = 0; |
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zlib_inflateInit(&stream); |
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} |
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return 0; |
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} |
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void cramfs_uncompress_exit(void) |
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{ |
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if (!--initialized) { |
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zlib_inflateEnd(&stream); |
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vfree(stream.workspace); |
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} |
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}
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