Commit 366c96a3 authored by Gao Xiang's avatar Gao Xiang Committed by Greg Kroah-Hartman

staging: erofs: introduce a customized LZ4 decompression

We have to reduce the memory cost as much as possible,
so we don't want to decompress more data beyond
the output buffer size, however "LZ4_decompress_safe_partial"
doesn't guarantee to stop at the arbitary end position,
but stop just after its current LZ4 "sequence" is completed.

Link: https://groups.google.com/forum/#!topic/lz4c/_3kkz5N6n00

Therefore, I hacked the LZ4 decompression logic by hand,
probably NOT the fastest approach, and hope for better
implementation.
Signed-off-by: default avatarMiao Xie <miaoxie@huawei.com>
Signed-off-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 55441958
......@@ -9,5 +9,5 @@ obj-$(CONFIG_EROFS_FS) += erofs.o
ccflags-y += -I$(src)/include
erofs-objs := super.o inode.o data.o namei.o dir.o utils.o
erofs-$(CONFIG_EROFS_FS_XATTR) += xattr.o
erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o
erofs-$(CONFIG_EROFS_FS_ZIP) += unzip_vle.o unzip_lz4.o
#ifndef __LZ4DEFS_H__
#define __LZ4DEFS_H__
/*
* lz4defs.h -- common and architecture specific defines for the kernel usage
* LZ4 - Fast LZ compression algorithm
* Copyright (C) 2011-2016, Yann Collet.
* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* You can contact the author at :
* - LZ4 homepage : http://www.lz4.org
* - LZ4 source repository : https://github.com/lz4/lz4
*
* Changed for kernel usage by:
* Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
*/
#include <asm/unaligned.h>
#include <linux/string.h> /* memset, memcpy */
#define FORCE_INLINE __always_inline
/*-************************************
* Basic Types
**************************************/
#include <linux/types.h>
typedef uint8_t BYTE;
typedef uint16_t U16;
typedef uint32_t U32;
typedef int32_t S32;
typedef uint64_t U64;
typedef uintptr_t uptrval;
/*-************************************
* Architecture specifics
**************************************/
#if defined(CONFIG_64BIT)
#define LZ4_ARCH64 1
#else
#define LZ4_ARCH64 0
#endif
#if defined(__LITTLE_ENDIAN)
#define LZ4_LITTLE_ENDIAN 1
#else
#define LZ4_LITTLE_ENDIAN 0
#endif
/*-************************************
* Constants
**************************************/
#define MINMATCH 4
#define WILDCOPYLENGTH 8
#define LASTLITERALS 5
#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
/* Increase this value ==> compression run slower on incompressible data */
#define LZ4_SKIPTRIGGER 6
#define HASH_UNIT sizeof(size_t)
#define KB (1 << 10)
#define MB (1 << 20)
#define GB (1U << 30)
#define MAXD_LOG 16
#define MAX_DISTANCE ((1 << MAXD_LOG) - 1)
#define STEPSIZE sizeof(size_t)
#define ML_BITS 4
#define ML_MASK ((1U << ML_BITS) - 1)
#define RUN_BITS (8 - ML_BITS)
#define RUN_MASK ((1U << RUN_BITS) - 1)
/*-************************************
* Reading and writing into memory
**************************************/
static FORCE_INLINE U16 LZ4_read16(const void *ptr)
{
return get_unaligned((const U16 *)ptr);
}
static FORCE_INLINE U32 LZ4_read32(const void *ptr)
{
return get_unaligned((const U32 *)ptr);
}
static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr)
{
return get_unaligned((const size_t *)ptr);
}
static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value)
{
put_unaligned(value, (U16 *)memPtr);
}
static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value)
{
put_unaligned(value, (U32 *)memPtr);
}
static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr)
{
return get_unaligned_le16(memPtr);
}
static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value)
{
return put_unaligned_le16(value, memPtr);
}
static FORCE_INLINE void LZ4_copy8(void *dst, const void *src)
{
#if LZ4_ARCH64
U64 a = get_unaligned((const U64 *)src);
put_unaligned(a, (U64 *)dst);
#else
U32 a = get_unaligned((const U32 *)src);
U32 b = get_unaligned((const U32 *)src + 1);
put_unaligned(a, (U32 *)dst);
put_unaligned(b, (U32 *)dst + 1);
#endif
}
/*
* customized variant of memcpy,
* which can overwrite up to 7 bytes beyond dstEnd
*/
static FORCE_INLINE void LZ4_wildCopy(void *dstPtr,
const void *srcPtr, void *dstEnd)
{
BYTE *d = (BYTE *)dstPtr;
const BYTE *s = (const BYTE *)srcPtr;
BYTE *const e = (BYTE *)dstEnd;
do {
LZ4_copy8(d, s);
d += 8;
s += 8;
} while (d < e);
}
static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val)
{
#if LZ4_LITTLE_ENDIAN
return __ffs(val) >> 3;
#else
return (BITS_PER_LONG - 1 - __fls(val)) >> 3;
#endif
}
static FORCE_INLINE unsigned int LZ4_count(
const BYTE *pIn,
const BYTE *pMatch,
const BYTE *pInLimit)
{
const BYTE *const pStart = pIn;
while (likely(pIn < pInLimit - (STEPSIZE - 1))) {
size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn);
if (!diff) {
pIn += STEPSIZE;
pMatch += STEPSIZE;
continue;
}
pIn += LZ4_NbCommonBytes(diff);
return (unsigned int)(pIn - pStart);
}
#if LZ4_ARCH64
if ((pIn < (pInLimit - 3))
&& (LZ4_read32(pMatch) == LZ4_read32(pIn))) {
pIn += 4;
pMatch += 4;
}
#endif
if ((pIn < (pInLimit - 1))
&& (LZ4_read16(pMatch) == LZ4_read16(pIn))) {
pIn += 2;
pMatch += 2;
}
if ((pIn < pInLimit) && (*pMatch == *pIn))
pIn++;
return (unsigned int)(pIn - pStart);
}
typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive;
typedef enum { byPtr, byU32, byU16 } tableType_t;
typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;
typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
typedef enum { full = 0, partial = 1 } earlyEnd_directive;
#endif
// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
/*
* linux/drivers/staging/erofs/unzip_lz4.c
*
* Copyright (C) 2018 HUAWEI, Inc.
* http://www.huawei.com/
* Created by Gao Xiang <gaoxiang25@huawei.com>
*
* Original code taken from 'linux/lib/lz4/lz4_decompress.c'
*/
/*
* LZ4 - Fast LZ compression algorithm
* Copyright (C) 2011 - 2016, Yann Collet.
* BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* You can contact the author at :
* - LZ4 homepage : http://www.lz4.org
* - LZ4 source repository : https://github.com/lz4/lz4
*
* Changed for kernel usage by:
* Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
*/
#include "internal.h"
#include <asm/unaligned.h>
#include "lz4defs.h"
/*
* no public solution to solve our requirement yet.
* see: <required buffer size for LZ4_decompress_safe_partial>
* https://groups.google.com/forum/#!topic/lz4c/_3kkz5N6n00
*/
static FORCE_INLINE int customized_lz4_decompress_safe_partial(
const void * const source,
void * const dest,
int inputSize,
int outputSize)
{
/* Local Variables */
const BYTE *ip = (const BYTE *) source;
const BYTE * const iend = ip + inputSize;
BYTE *op = (BYTE *) dest;
BYTE * const oend = op + outputSize;
BYTE *cpy;
static const unsigned int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };
static const int dec64table[] = { 0, 0, 0, -1, 0, 1, 2, 3 };
/* Empty output buffer */
if (unlikely(outputSize == 0))
return ((inputSize == 1) && (*ip == 0)) ? 0 : -1;
/* Main Loop : decode sequences */
while (1) {
size_t length;
const BYTE *match;
size_t offset;
/* get literal length */
unsigned int const token = *ip++;
length = token>>ML_BITS;
if (length == RUN_MASK) {
unsigned int s;
do {
s = *ip++;
length += s;
} while ((ip < iend - RUN_MASK) & (s == 255));
if (unlikely((size_t)(op + length) < (size_t)(op))) {
/* overflow detection */
goto _output_error;
}
if (unlikely((size_t)(ip + length) < (size_t)(ip))) {
/* overflow detection */
goto _output_error;
}
}
/* copy literals */
cpy = op + length;
if ((cpy > oend - WILDCOPYLENGTH) ||
(ip + length > iend - (2 + 1 + LASTLITERALS))) {
if (cpy > oend) {
memcpy(op, ip, length = oend - op);
op += length;
break;
}
if (unlikely(ip + length > iend)) {
/*
* Error :
* read attempt beyond
* end of input buffer
*/
goto _output_error;
}
memcpy(op, ip, length);
ip += length;
op += length;
if (ip > iend - 2)
break;
/* Necessarily EOF, due to parsing restrictions */
/* break; */
} else {
LZ4_wildCopy(op, ip, cpy);
ip += length;
op = cpy;
}
/* get offset */
offset = LZ4_readLE16(ip);
ip += 2;
match = op - offset;
if (unlikely(match < (const BYTE *)dest)) {
/* Error : offset outside buffers */
goto _output_error;
}
/* get matchlength */
length = token & ML_MASK;
if (length == ML_MASK) {
unsigned int s;
do {
s = *ip++;
if (ip > iend - LASTLITERALS)
goto _output_error;
length += s;
} while (s == 255);
if (unlikely((size_t)(op + length) < (size_t)op)) {
/* overflow detection */
goto _output_error;
}
}
length += MINMATCH;
/* copy match within block */
cpy = op + length;
if (unlikely(cpy >= oend - WILDCOPYLENGTH)) {
if (cpy >= oend) {
while (op < oend)
*op++ = *match++;
break;
}
goto __match;
}
/* costs ~1%; silence an msan warning when offset == 0 */
LZ4_write32(op, (U32)offset);
if (unlikely(offset < 8)) {
const int dec64 = dec64table[offset];
op[0] = match[0];
op[1] = match[1];
op[2] = match[2];
op[3] = match[3];
match += dec32table[offset];
memcpy(op + 4, match, 4);
match -= dec64;
} else {
LZ4_copy8(op, match);
match += 8;
}
op += 8;
if (unlikely(cpy > oend - 12)) {
BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);
if (op < oCopyLimit) {
LZ4_wildCopy(op, match, oCopyLimit);
match += oCopyLimit - op;
op = oCopyLimit;
}
__match:
while (op < cpy)
*op++ = *match++;
} else {
LZ4_copy8(op, match);
if (length > 16)
LZ4_wildCopy(op + 8, match + 8, cpy);
}
op = cpy; /* correction */
}
DBG_BUGON((void *)ip - source > inputSize);
DBG_BUGON((void *)op - dest > outputSize);
/* Nb of output bytes decoded */
return (int) ((void *)op - dest);
/* Overflow error detected */
_output_error:
return -ERANGE;
}
int z_erofs_unzip_lz4(void *in, void *out, size_t inlen, size_t outlen)
{
int ret = customized_lz4_decompress_safe_partial(in,
out, inlen, outlen);
if (ret >= 0)
return ret;
/*
* LZ4_decompress_safe will return an error code
* (< 0) if decompression failed
*/
errln("%s, failed to decompress, in[%p, %zu] outlen[%p, %zu]",
__func__, in, inlen, out, outlen);
WARN_ON(1);
print_hex_dump(KERN_DEBUG, "raw data [in]: ", DUMP_PREFIX_OFFSET,
16, 1, in, inlen, true);
print_hex_dump(KERN_DEBUG, "raw data [out]: ", DUMP_PREFIX_OFFSET,
16, 1, out, outlen, true);
return -EIO;
}
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment