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![Kyungsik Lee](/assets/img/avatar_default.png)
Add support for extracting LZ4-compressed kernel images, as well as LZ4-compressed ramdisk images in the kernel boot process. Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Borislav Petkov <bp@alien8.de> Cc: Florian Fainelli <florian@openwrt.org> Cc: Yann Collet <yann.collet.73@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
187 lines
3.8 KiB
C
187 lines
3.8 KiB
C
/*
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* Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
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*
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* Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifdef STATIC
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#define PREBOOT
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#include "lz4/lz4_decompress.c"
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#else
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#include <linux/decompress/unlz4.h>
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#endif
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#include <linux/types.h>
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#include <linux/lz4.h>
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#include <linux/decompress/mm.h>
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#include <linux/compiler.h>
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#include <asm/unaligned.h>
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/*
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* Note: Uncompressed chunk size is used in the compressor side
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* (userspace side for compression).
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* It is hardcoded because there is not proper way to extract it
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* from the binary stream which is generated by the preliminary
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* version of LZ4 tool so far.
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*/
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#define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
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#define ARCHIVE_MAGICNUMBER 0x184C2102
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STATIC inline int INIT unlz4(u8 *input, int in_len,
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int (*fill) (void *, unsigned int),
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int (*flush) (void *, unsigned int),
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u8 *output, int *posp,
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void (*error) (char *x))
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{
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int ret = -1;
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size_t chunksize = 0;
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size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
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u8 *inp;
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u8 *inp_start;
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u8 *outp;
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int size = in_len;
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#ifdef PREBOOT
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size_t out_len = get_unaligned_le32(input + in_len);
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#endif
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size_t dest_len;
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if (output) {
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outp = output;
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} else if (!flush) {
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error("NULL output pointer and no flush function provided");
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goto exit_0;
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} else {
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outp = large_malloc(uncomp_chunksize);
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if (!outp) {
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error("Could not allocate output buffer");
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goto exit_0;
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}
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}
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if (input && fill) {
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error("Both input pointer and fill function provided,");
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goto exit_1;
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} else if (input) {
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inp = input;
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} else if (!fill) {
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error("NULL input pointer and missing fill function");
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goto exit_1;
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} else {
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inp = large_malloc(lz4_compressbound(uncomp_chunksize));
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if (!inp) {
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error("Could not allocate input buffer");
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goto exit_1;
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}
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}
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inp_start = inp;
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if (posp)
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*posp = 0;
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if (fill)
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fill(inp, 4);
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chunksize = get_unaligned_le32(inp);
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if (chunksize == ARCHIVE_MAGICNUMBER) {
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inp += 4;
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size -= 4;
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} else {
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error("invalid header");
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goto exit_2;
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}
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if (posp)
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*posp += 4;
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for (;;) {
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if (fill)
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fill(inp, 4);
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chunksize = get_unaligned_le32(inp);
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if (chunksize == ARCHIVE_MAGICNUMBER) {
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inp += 4;
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size -= 4;
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if (posp)
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*posp += 4;
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continue;
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}
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inp += 4;
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size -= 4;
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if (posp)
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*posp += 4;
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if (fill) {
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if (chunksize > lz4_compressbound(uncomp_chunksize)) {
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error("chunk length is longer than allocated");
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goto exit_2;
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}
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fill(inp, chunksize);
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}
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#ifdef PREBOOT
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if (out_len >= uncomp_chunksize) {
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dest_len = uncomp_chunksize;
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out_len -= dest_len;
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} else
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dest_len = out_len;
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ret = lz4_decompress(inp, &chunksize, outp, dest_len);
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#else
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dest_len = uncomp_chunksize;
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ret = lz4_decompress_unknownoutputsize(inp, chunksize, outp,
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&dest_len);
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#endif
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if (ret < 0) {
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error("Decoding failed");
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goto exit_2;
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}
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if (flush && flush(outp, dest_len) != dest_len)
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goto exit_2;
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if (output)
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outp += dest_len;
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if (posp)
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*posp += chunksize;
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size -= chunksize;
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if (size == 0)
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break;
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else if (size < 0) {
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error("data corrupted");
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goto exit_2;
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}
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inp += chunksize;
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if (fill)
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inp = inp_start;
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}
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ret = 0;
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exit_2:
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if (!input)
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large_free(inp_start);
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exit_1:
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if (!output)
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large_free(outp);
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exit_0:
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return ret;
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}
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#ifdef PREBOOT
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STATIC int INIT decompress(unsigned char *buf, int in_len,
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int(*fill)(void*, unsigned int),
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int(*flush)(void*, unsigned int),
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unsigned char *output,
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int *posp,
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void(*error)(char *x)
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)
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{
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return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
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}
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#endif
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