lib/lz4: stop forking upstream LZ4, vendor it instead
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v2 cover lib/lz4: stop forking upstream LZ4, vendor it instead
In reply to a message not in the archiveThe in-kernel LZ4 is a fork. The decompressor was last synced with upstream v1.8.3 in 2018 and the compressor with v1.7.3 in 2017, both by hand. Upstream has made 488 commits against lib/ since, and the gap is maintained one cherry-pick at a time.
That has left real bugs in place for example the forked LZ4_decompress_fast() has no bounds checks on its input, so corrupted input reads past its end and before the output buffer.
This series vendors the upstream sources unmodified and adapts them at build time, so a re-sync becomes a directory copy:
upstream/lz4.c, upstream/lz4.h verbatim upstream sources
upstream/lz4hc.c, upstream/lz4hc.h
lz4_deps.h the build environment lz4_kernel_api.h hands the LZ4 names back freestanding/ ISO C headers -nostdinc drops lz4_compress.c the kernel's entry points
lz4_decompress.c
lz4hc_compress.c
Patches 1-3 apply to the fork as it stands: patch 1 moves the pre-boot decompressor off LZ4_decompress_fast(), patch 2 removes it and its variants, and patch 3 stops zram's lz4hc backend resetting its stream for every page. Patch 4 imports the sources. Patches 5-7 backport the upstream fixes the kernel needs on top of v1.10.0. Patch 8 adds the build environment. Patch 9 puts the freestanding headers on the pre-boot decompressor path. Patches 10, 11 and 13 convert the compressor, HC compressor and decompressor in turn; patch 12 widens the in-place margin erofs relies on for the new decoder. Patch 14 drops the last duplicated prototype list. Patch 15 gives lib/lz4 a MAINTAINERS entry, which it has never had.
This is meant to go through Andrew's tree; patch 9 needs acks from the boot maintainers.
The exported API changes in four ways.
The three stream types become incomplete. <linux/lz4.h> spelled out their layout for the fork's benefit, upstream headers define the same types and lib/decompress_unlz4.c ends up with both in one translation unit. Callers allocate LZ4_MEM_COMPRESS, LZ4HC_MEM_COMPRESS or LZ4_MEM_DECOMPRESS bytes instead of sizeof() every caller but zram already did. Each conversion patch makes its own type incomplete so no step leaves the tree broken.
Sixteen macros go with them: the hash geometry (LZ4_HASHLOG, LZ4_HASHTABLESIZE, LZ4_HASH_SIZE_U32, LZ4HC_DICTIONARY_LOGSIZE, LZ4HC_MAXD, LZ4HC_MAXD_MASK, LZ4HC_HASH_LOG, LZ4HC_HASHTABLESIZE, LZ4HC_HASH_MASK) and the sizes derived from it (LZ4_MEMORY_USAGE, LZ4_STREAMSIZE{,_U64}, LZ4_STREAMHCSIZE{,_SIZET}, LZ4_STREAMDECODESIZE{,_U64}). They existed to lay out structures the fork defined here none has an in tree user outside lib/lz4. LZ4_compressBound() goes too a static inline whose only caller was lib/decompress_unlz4.c, now using the LZ4_COMPRESSBOUND() macro.
LZ4_MEM_DECOMPRESS and LZ4HC_CLAMP_CLEVEL are new.
LZ4_decompress_fast(), LZ4_decompress_fast_continue() and LZ4_decompress_fast_usingDict() go. Upstream has deprecated them since v1.9, and their last in-tree user, the pre-boot decompressor, now uses LZ4_decompress_safe_partial().
There are some behaviour changes. All of them come from upstream rather than from this series and I have kept them rather than patching them
out: a local fix on top of vendored sources is exactly the divergence this series exists to remove.
- LZ4HC levels 10 and up are clamped to 9. Upstream routes them to its optimal parser, whose ~64K opt[] does not fit a kernel stack. The fork had no optimal parser at all - level only scaled search depth - so its levels 10-16 beat its own level 9 by 0.01%. Clamping rather than rejecting keeps existing f2fs and zram settings working.
- LZ4_decompress_safe_partial() with a zero-length target returns 0 rather than -1, matching upstream since 725cb0aafdf7. No in-tree caller depends on it.
- The compressors require wrkmem aligned to 8 bytes. Upstream checks this and LZ4_initStream() returns NULL, which upstream's own callers then dereference or ignore. The entry points check the alignment themselves, warn once and fail the call. Every in-tree caller uses kmalloc() or vmalloc() and is already aligned; <linux/lz4.h> now documents the requirement.
The layout follows lib/zstd, which keeps upstream's sources in a subdirectory and the kernel glue on top. zstd has an upstream import tool and an upstream zstd_deps.h; LZ4 has neither, so the kernel glue here lives outside the vendored files.
The import is the v1.10.0 release tag. It does not build under -Wmissing-prototypes without upstream commit 5ef1f16929b5, which patch 5 backports. Patch 6 backports upstream's arm64 fast decode loop and patch 7 its match length limit fix; those are the only deviations from the tag. The rest of PR #1753 fixes code added after v1.10.0, so it will come with the next release.
checkpatch reports some 3500 errors against patch 4: upstream's coding style, and no SPDX tags, in files kept verbatim.
Measured in the kernel: three kernels differing only in lib/lz4, booted one core under KVM, each reading 1.3GB of kernel source from an LZ4 erofs image with the page cache dropped before every pass. For v2 this was remeasured with more runs on an idle machine: median of 140 passes. The middle column is upstream v1.10.0 with LZ4_FAST_DEC_LOOP=0, to separate the version bump from the decode loop upstream added in v1.9.0.
erofs read, MB/s
erofs cluster today v1.10.0 + fast loop net
4K 2486 2549 2665 +7%
64K 3013 3104 3225 +7%The same three decoders at the library level, each block decompressed on its own the way zram treats a page. x86_64, the fork's and upstream's sources built with the kernel's code generation flags (so no SSE), all decoding the same compressed input, median of 21 interleaved runs. The first corpus is upstream's tests/datagen with a fixed seed, so it is byte-identical anywhere; the second is a tar of kernel sources:
decompression, MB/s
corpus block ratio today v1.10.0 + fast loop net
datagen -s0 -P60 4K 1.09x 4584 4535 5097 +11%
16K 1.34x 3960 3978 4828 +22%
64K 1.90x 4797 4802 5598 +17%
256K 1.92x 6749 6559 7600 +13%
kernel source tar 4K 2.29x 3719 3832 4219 +13%
16K 2.57x 3778 3880 4203 +11%
64K 2.80x 3792 3886 4179 +10%
256K 2.95x 4165 4280 4750 +14%Compression is not uniformly faster: lz4hc on small blocks of poorly compressible data is up to 15% slower. Patches 10 and 11 have the numbers.
The cost is size: lib/lz4 grows from 45K to 86K of text on x86_64, lz4hc most (12K to 39K). That is upstream code the fork never had.
---
Changes in v2:
- Drop the RFC prefix
- New patches 1-2: move the pre-boot decompressor to
LZ4_decompress_safe_partial() and remove LZ4_decompress_fast() and its
variants from the fork, ahead of the import (Sergey)
- New patch 3: zram's lz4hc backend resets its stream once, not per page
- New patches 6-7: backport upstream's arm64 fast decode loop (Sergey)
and its match length limit fix
- New patch 12: widen LZ4_DECOMPRESS_INPLACE_MARGIN for the fast decode
loop
- Compressor entry points check wrkmem alignment, warn and fail (Sergey)
- Patch 13 names the upstream counterpart of each retired local patch
(Sergey)
- MAINTAINERS: also cover lib/decompress_unlz4.c and include/linux/decompress/unlz4.h (Eric)
- Remeasure erofs reads with more runs on an idle machine
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Michal Wilczynski (15):
lib/decompress_unlz4: use LZ4_decompress_safe_partial() before boot lib/lz4: remove LZ4_decompress_fast() and its variants
zram: lz4hc: reset the dictionary stream once, not per page lib/lz4: import upstream LZ4 sources verbatim
lib/lz4: backport upstream's -Wmissing-prototypes fix lib/lz4: backport upstream's aarch64 fast decode loop enablement lib/lz4: backport upstream's match length limit fix lib/lz4: add the build environment for the vendored sources
arch: boot: put the LZ4 freestanding headers on the decompressor path lib/lz4: switch the compressor to the vendored sources lib/lz4: switch the HC compressor to the vendored sources lib/lz4: widen LZ4_DECOMPRESS_INPLACE_MARGIN for the fast decode loop lib/lz4: switch the decompressor to the vendored sources lib/lz4: replace lz4_kernel_api.h's prototypes with <linux/lz4.h>
MAINTAINERS: add an entry for the LZ4 compression library
Documentation/filesystems/f2fs.rst | 2 + MAINTAINERS | 10 + arch/arm/boot/compressed/Makefile | 3 + arch/mips/boot/compressed/Makefile | 4 + arch/parisc/boot/compressed/Makefile | 3 + arch/s390/boot/Makefile | 3 + arch/x86/boot/compressed/Makefile | 3 + drivers/block/zram/backend_lz4.c | 8 +- drivers/block/zram/backend_lz4hc.c | 8 +- include/linux/lz4.h | 253 +-- lib/decompress_unlz4.c | 17 +- lib/lz4/Makefile | 16 +- lib/lz4/freestanding/limits.h | 14 + lib/lz4/freestanding/stddef.h | 15 + lib/lz4/freestanding/stdint.h | 14 + lib/lz4/freestanding/string.h | 14 + lib/lz4/lz4_compress.c | 946 +----------- lib/lz4/lz4_decompress.c | 724 +-------- lib/lz4/lz4_deps.h | 118 ++ lib/lz4/lz4_kernel_api.h | 34 + lib/lz4/lz4defs.h | 247 --- lib/lz4/lz4hc_compress.c | 792 +--------- lib/lz4/upstream/lz4.c | 2824 ++++++++++++++++++++++++++++++++++ lib/lz4/upstream/lz4.h | 884 +++++++++++ lib/lz4/upstream/lz4hc.c | 2192 ++++++++++++++++++++++++++ lib/lz4/upstream/lz4hc.h | 414 +++++ 26 files changed, 6813 insertions(+), 2749 deletions(-)
---
base-commit: 93f51579e7df248780214094418f205253383cc5
change-id: 20260904-lz4-vendor-upstream-4bc2202d0ffc
Best regards,
Signature · 1 line
Michal Wilczynski <[email protected]>
PATCH v2 1/15 lib/decompress_unlz4: use LZ4_decompress_safe_partial() before boot
The pre-boot decompressor is the only in-tree user of LZ4_decompress_fast(), which upstream has deprecated since v1.9. It never checks the input against the chunk length in the header.
Decode with LZ4_decompress_safe_partial() instead, bounded by the chunk length and by the expected output length. Count every chunk against the size the image ends with, and fail a chunk that decodes short or comes after that size is reached.
x86 decompresses in place; the margin arch/x86/boot/header.S reserves, (output >> 8) + 128K, covers the safe decoder's 32-byte overshoot.
--- lib/decompress_unlz4.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)
lib/decompress_unlz4.c +8 -5
@@ -151,14 +151,17 @@ STATIC inline int INIT unlz4(u8 *input, long in_len, } }#ifdef PREBOOT -if (out_len >= uncomp_chunksize) { +if (out_len >= uncomp_chunksize) dest_len = uncomp_chunksize; - out_len -= dest_len; - }else +else dest_len = out_len; + out_len -= dest_len; - ret =LZ4_decompress_fast (inp, outp, dest_len); - chunksize = ret; + ret =LZ4_decompress_safe_partial (inp, outp, chunksize, + dest_len, dest_len); +/* A chunk once the image's stated size is reached is corrupt. */ +if (!dest_len || ret != (int )dest_len) + ret =-1 ;#else dest_len = uncomp_chunksize;
Signature · 1 line
2.34.1
PATCH v2 2/15 lib/lz4: remove LZ4_decompress_fast() and its variants
In reply to Michal WilczynskiLZ4_decompress_fast(), LZ4_decompress_fast_continue() and LZ4_decompress_fast_usingDict() have no users left. Upstream has deprecated all three since v1.9: they take only the decompressed size, so a corrupt or malicious stream has nothing to stop the decoder from reading past the end of its input.
Remove them, their exports and their declarations in <linux/lz4.h>, along with the two helpers only they used. Doing it before lib/lz4 moves to upstream LZ4 keeps them out of the glue that move adds.
--- include/linux/lz4.h | 81 ---------------------------------------------- lib/lz4/lz4_decompress.c | 84 ------------------------------------------------ 2 files changed, 165 deletions(-)
include/linux/lz4.h +0 -81
@@ -249,27 +249,6 @@ int LZ4_compress_destSize(const char *source, char *dest, int *sourceSizePtr,* Decompression Functions **************************************************************************/ -/** -* LZ4_decompress_fast() - Decompresses data from 'source' into 'dest' -* @source: source address of the compressed data -* @dest: output buffer address of the uncompressed data -* which must be already allocated with 'originalSize' bytes -* @originalSize: is the original and therefore uncompressed size -* -* Decompresses data from 'source' into 'dest'. -* This function fully respect memory boundaries for properly formed -* compressed data. -* It is a bit faster than LZ4_decompress_safe(). -* However, it does not provide any protection against intentionally -* modified data stream (malicious input). -* Use this function in trusted environment only -* (data to decode comes from a trusted source). -* -* Return: number of bytes read from the source buffer -* or a negative result if decompression fails. -*/ -int LZ4_decompress_fast (const char *source,char *dest,int originalSize); -/** * LZ4_decompress_safe() - Decompression protected against buffer overflow * @source: source address of the compressed data
@@ -561,44 +540,6 @@ int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode, const char *source, char *dest, int compressedSize, int maxDecompressedSize); -/** -* LZ4_decompress_fast_continue() - Decompress blocks in streaming mode -* @LZ4_streamDecode: the 'LZ4_streamDecode_t' structure -* @source: source address of the compressed data -* @dest: output buffer address of the uncompressed data -* which must be already allocated with 'originalSize' bytes -* @originalSize: is the original and therefore uncompressed size -* -* This decoding function allows decompression of multiple blocks -* in "streaming" mode. -* Previously decoded blocks *must* remain available at the memory position -* where they were decoded (up to 64 KB) -* In the case of a ring buffers, decoding buffer must be either : -* - Exactly same size as encoding buffer, with same update rule -* (block boundaries at same positions) In which case, -* the decoding & encoding ring buffer can have any size, -* including very small ones ( < 64 KB). -* - Larger than encoding buffer, by a minimum of maxBlockSize more bytes. -* maxBlockSize is implementation dependent. -* It's the maximum size you intend to compress into a single block. -* In which case, encoding and decoding buffers do not need -* to be synchronized, and encoding ring buffer can have any size, -* including small ones ( < 64 KB). -* - _At least_ 64 KB + 8 bytes + maxBlockSize. -* In which case, encoding and decoding buffers do not need to be -* synchronized, and encoding ring buffer can have any size, -* including larger than decoding buffer. W -* Whenever these conditions are not possible, save the last 64KB of decoded -* data into a safe buffer, and indicate where it is saved -* using LZ4_setStreamDecode() -* -* Return: number of bytes decompressed into destination buffer -* (necessarily <= maxDecompressedSize) -* or a negative result in case of error -*/ -int LZ4_decompress_fast_continue (LZ4_streamDecode_t *LZ4_streamDecode, -const char *source,char *dest,int originalSize); -/** * LZ4_decompress_safe_usingDict() - Same as LZ4_setStreamDecode() * followed by LZ4_decompress_safe_continue()
@@ -623,28 +564,6 @@ int LZ4_decompress_safe_usingDict(const char *source, char *dest, int compressedSize, int maxDecompressedSize, const char *dictStart, int dictSize); -/** -* LZ4_decompress_fast_usingDict() - Same as LZ4_setStreamDecode() -* followed by LZ4_decompress_fast_continue() -* @source: source address of the compressed data -* @dest: output buffer address of the uncompressed data -* which must be already allocated with 'originalSize' bytes -* @originalSize: is the original and therefore uncompressed size -* @dictStart: pointer to the start of the dictionary in memory -* @dictSize: size of dictionary -* -* This decoding function works the same as -* a combination of LZ4_setStreamDecode() followed by -* LZ4_decompress_fast_continue() -* It is stand-alone, and doesn't need an LZ4_streamDecode_t structure. -* -* Return: number of bytes decompressed into destination buffer -* (necessarily <= maxDecompressedSize) -* or a negative result in case of error -*/ -int LZ4_decompress_fast_usingDict (const char *source,char *dest, -int originalSize,const char *dictStart,int dictSize); -#define LZ4_DECOMPRESS_INPLACE_MARGIN (compressedSize) (((compressedSize) >> 8) + 32)#ifndef LZ4_DISTANCE_MAX /* history window size; can be user-defined at compile time */
lib/lz4/lz4_decompress.c +0 -84
120 lines not on this page · raw message
Signature · 1 line
2.34.1
PATCH v2 3/15 zram: lz4hc: reset the dictionary stream once, not per page
In reply to Michal WilczynskiWith a dictionary, lz4hc_compress() calls LZ4_resetStreamHC() and then LZ4_loadDictHC() for every page. LZ4_loadDictHC() re-initialises the stream itself and keeps the level, so one reset at creation is enough.
The reset is cheap today, but upstream LZ4, which lib/lz4 moves to later in this series, clears the whole 256K state in both calls. Reset once in lz4hc_create() instead.
--- drivers/block/zram/backend_lz4hc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/block/zram/backend_lz4hc.c +2 -2
@@ -72,6 +72,7 @@ static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx) zctx->cstrm =kzalloc_obj (*zctx->cstrm);if (!zctx->cstrm) goto error; +LZ4_resetStreamHC (zctx->cstrm, params->level); }return 0 ;
@@ -92,8 +93,7 @@ static int lz4hc_compress(struct zcomp_params *params, struct zcomp_ctx *ctx, req->dst_len, params->level, zctx->mem); }else { -/* Cstrm needs to be reset */ -LZ4_resetStreamHC (zctx->cstrm, params->level); +/* Reloading the dict resets cstrm and keeps its level */ ret =LZ4_loadDictHC (zctx->cstrm, params->dict, params->dict_sz);if (ret != params->dict_sz)
Signature · 1 line
2.34.1
PATCH v2 4/15 lib/lz4: import upstream LZ4 sources verbatim
In reply to Michal WilczynskiAdd the four upstream files under lib/lz4/upstream/ without modification. Nothing builds them yet; a later patch adds the build environment.
Copied without modification from the v1.10.0 release tag of
https://github.com/lz4/lz4, tagged 2024-07-21.
--- lib/lz4/upstream/lz4.c | 2829 ++++++++++++++++++++++++++++++++++++++++++++++ lib/lz4/upstream/lz4.h | 884 +++++++++++++++ lib/lz4/upstream/lz4hc.c | 2192 +++++++++++++++++++++++++++++++++++ lib/lz4/upstream/lz4hc.h | 414 +++++++ 4 files changed, 6319 insertions(+)
lib/lz4/upstream/lz4.c new file +2829 -0
@@ -0,0 +1,2829 @@ +/* + LZ4 - Fast LZ compression algorithm + Copyright (C) 2011-2023, 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 +*/ + +/*-************************************ +* Tuning parameters +**************************************/ +/* + * LZ4_HEAPMODE : + * Select how stateless compression functions like `LZ4_compress_default()` + * allocate memory for their hash table, + * in memory stack (0:default, fastest), or in memory heap (1:requires malloc()). + */ +#ifndef LZ4_HEAPMODE +# define LZ4_HEAPMODE 0 +#endif + +/* + * LZ4_ACCELERATION_DEFAULT : + * Select "acceleration" for LZ4_compress_fast() when parameter value <= 0 + */ +#define LZ4_ACCELERATION_DEFAULT 1 +/* + * LZ4_ACCELERATION_MAX : + * Any "acceleration" value higher than this threshold + * get treated as LZ4_ACCELERATION_MAX instead (fix #876) + */ +#define LZ4_ACCELERATION_MAX 65537 + + +/*-************************************ +* CPU Feature Detection +**************************************/ +/* LZ4_FORCE_MEMORY_ACCESS + * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable. + * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal. + * The below switch allow to select different access method for improved performance. + * Method 0 (default) : use `memcpy()`. Safe and portable. + * Method 1 : `__packed` statement. It depends on compiler extension (ie, not portable). + * This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`. + * Method 2 : direct access. This method is portable but violate C standard. + * It can generate buggy code on targets which assembly generation depends on alignment. + * But in some circumstances, it's the only known way to get the most performance (ie GCC + ARMv6) + * See https://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details. + * Prefer these methods in priority order (0 > 1 > 2) + */ +#ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally */ +# if defined(__GNUC__) && \ + ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) \ + || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) ) +# define LZ4_FORCE_MEMORY_ACCESS 2 +# elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || defined(__GNUC__) || defined(_MSC_VER) +# define LZ4_FORCE_MEMORY_ACCESS 1 +# endif +#endif + +/* + * LZ4_FORCE_SW_BITCOUNT + * Define this parameter if your target system or compiler does not support hardware bit count + */ +#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for WinCE doesn't support Hardware bit count */ +# undef LZ4_FORCE_SW_BITCOUNT /* avoid double def */ +# define LZ4_FORCE_SW_BITCOUNT +#endif + + + +/*-************************************ +* Dependency +**************************************/ +/* + * LZ4_SRC_INCLUDED: + * Amalgamation flag, whether lz4.c is included + */ +#ifndef LZ4_SRC_INCLUDED +# define LZ4_SRC_INCLUDED 1 +#endif + +#ifndef LZ4_DISABLE_DEPRECATE_WARNINGS +# define LZ4_DISABLE_DEPRECATE_WARNINGS /* due to LZ4_decompress_safe_withPrefix64k */ +#endif + +#ifndef LZ4_STATIC_LINKING_ONLY +# define LZ4_STATIC_LINKING_ONLY +#endif +#include "lz4.h" +/* see also "memory routines" below */ + + +/*-************************************ +* Compiler Options +**************************************/ +#if defined(_MSC_VER) && (_MSC_VER >= 1400) /* Visual Studio 2005+ */ +# include <intrin.h> /* only present in VS2005+ */ +# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ +# pragma warning(disable : 6237) /* disable: C6237: conditional expression is always 0 */ +# pragma warning(disable : 6239) /* disable: C6239: (<non-zero constant> && <expression>) always evaluates to the result of <expression> */ +# pragma warning(disable : 6240) /* disable: C6240: (<expression> && <non-zero constant>) always evaluates to the result of <expression> */ +# pragma warning(disable : 6326) /* disable: C6326: Potential comparison of a constant with another constant */ +#endif /* _MSC_VER */ + +#ifndef LZ4_FORCE_INLINE +# if defined (_MSC_VER) && !defined (__clang__) /* MSVC */ +# define LZ4_FORCE_INLINE static __forceinline +# else +# if defined (__cplusplus) || defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ +# if defined (__GNUC__) || defined (__clang__) +# define LZ4_FORCE_INLINE static inline __attribute__((always_inline)) +# else +# define LZ4_FORCE_INLINE static inline +# endif +# else +# define LZ4_FORCE_INLINE static +# endif /* __STDC_VERSION__ */ +# endif /* _MSC_VER */ +#endif /* LZ4_FORCE_INLINE */ + +/* LZ4_FORCE_O2 and LZ4_FORCE_INLINE + * gcc on ppc64le generates an unrolled SIMDized loop for LZ4_wildCopy8, + * together with a simple 8-byte copy loop as a fall-back path. + * However, this optimization hurts the decompression speed by >30%, + * because the execution does not go to the optimized loop + * for typical compressible data, and all of the preamble checks + * before going to the fall-back path become useless overhead. + * This optimization happens only with the -O3 flag, and -O2 generates + * a simple 8-byte copy loop. + * With gcc on ppc64le, all of the LZ4_decompress_* and LZ4_wildCopy8 + * functions are annotated with __attribute__((optimize("O2"))), + * and also LZ4_wildCopy8 is forcibly inlined, so that the O2 attribute + * of LZ4_wildCopy8 does not affect the compression speed. + */ +#if defined(__PPC64__) && defined(__LITTLE_ENDIAN__) && defined(__GNUC__) && !defined(__clang__) +# define LZ4_FORCE_O2 __attribute__((optimize("O2"))) +# undef LZ4_FORCE_INLINE +# define LZ4_FORCE_INLINE static __inline __attribute__((optimize("O2"),always_inline)) +#else +# define LZ4_FORCE_O2 +#endif + +#if (defined(__GNUC__) && (__GNUC__ >= 3)) || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) || defined(__clang__) +# define expect(expr,value) (__builtin_expect ((expr),(value)) ) +#else +# define expect(expr,value) (expr) +#endif + +#ifndef likely +#define likely(expr) expect((expr) != 0, 1) +#endif +#ifndef unlikely +#define unlikely(expr) expect((expr) != 0, 0) +#endif + +/* Should the alignment test prove unreliable, for some reason, + * it can be disabled by setting LZ4_ALIGN_TEST to 0 */ +#ifndef LZ4_ALIGN_TEST /* can be externally provided */ +# define LZ4_ALIGN_TEST 1 +#endif + + +/*-************************************ +* Memory routines +**************************************/ + +/*! LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION : + * Disable relatively high-level LZ4/HC functions that use dynamic memory + * allocation functions (malloc(), calloc(), free()). + * + * Note that this is a compile-time switch. And since it disables + * public/stable LZ4 v1 API functions, we don't recommend using this + * symbol to generate a library for distribution. + * + * The following public functions are removed when this symbol is defined. + * - lz4 : LZ4_createStream, LZ4_freeStream, + * LZ4_createStreamDecode, LZ4_freeStreamDecode, LZ4_create (deprecated) + * - lz4hc : LZ4_createStreamHC, LZ4_freeStreamHC, + * LZ4_createHC (deprecated), LZ4_freeHC (deprecated) + * - lz4frame, lz4file : All LZ4F_* functions + */ +#if defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) +# define ALLOC(s) lz4_error_memory_allocation_is_disabled +# define ALLOC_AND_ZERO(s) lz4_error_memory_allocation_is_disabled +# define FREEMEM(p) lz4_error_memory_allocation_is_disabled +#elif defined(LZ4_USER_MEMORY_FUNCTIONS) +/* memory management functions can be customized by user project. + * Below functions must exist somewhere in the Project + * and be available at link time */ +void* LZ4_malloc(size_t s); +void* LZ4_calloc(size_t n, size_t s); +void LZ4_free(void* p); +# define ALLOC(s) LZ4_malloc(s) +# define ALLOC_AND_ZERO(s) LZ4_calloc(1,s) +# define FREEMEM(p) LZ4_free(p) +#else +# include <stdlib.h> /* malloc, calloc, free */ +# define ALLOC(s) malloc(s) +# define ALLOC_AND_ZERO(s) calloc(1,s) +# define FREEMEM(p) free(p) +#endif + +#if ! LZ4_FREESTANDING +# include <string.h> /* memset, memcpy */ +#endif +#if !defined(LZ4_memset) +# define LZ4_memset(p,v,s) memset((p),(v),(s)) +#endif +#define MEM_INIT(p,v,s) LZ4_memset((p),(v),(s)) + + +/*-************************************ +* Common Constants +**************************************/ +#define MINMATCH 4 + +#define WILDCOPYLENGTH 8 +#define LASTLITERALS 5 /* see ../doc/lz4_Block_format.md#parsing-restrictions */ +#define MFLIMIT 12 /* see ../doc/lz4_Block_format.md#parsing-restrictions */ +#define MATCH_SAFEGUARD_DISTANCE ((2*WILDCOPYLENGTH) - MINMATCH) /* ensure it's possible to write 2 x wildcopyLength without overflowing output buffer */ +#define FASTLOOP_SAFE_DISTANCE 64 +static const int LZ4_minLength = (MFLIMIT+1); + +#define KB *(1 <<10) +#define MB *(1 <<20) +#define GB *(1U<<30) + +#define LZ4_DISTANCE_ABSOLUTE_MAX 65535 +#if (LZ4_DISTANCE_MAX > LZ4_DISTANCE_ABSOLUTE_MAX) /* max supported by LZ4 format */ +# error "LZ4_DISTANCE_MAX is too big : must be <= 65535" +#endif + +#define ML_BITS 4 +#define ML_MASK ((1U<<ML_BITS)-1) +#define RUN_BITS (8-ML_BITS) +#define RUN_MASK ((1U<<RUN_BITS)-1) + + +/*-************************************ +* Error detection +**************************************/ +#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=1) +# include <assert.h> +#else +# ifndef assert +# define assert(condition) ((void)0) +# endif +#endif + +#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use after variable declarations */ + +#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2) +# include <stdio.h> + static int g_debuglog_enable = 1; +# define DEBUGLOG(l, ...) { \ + if ((g_debuglog_enable) && (l<=LZ4_DEBUG)) { \ + fprintf(stderr, __FILE__ " %i: ", __LINE__); \ + fprintf(stderr, __VA_ARGS__); \ + fprintf(stderr, " \n"); \ + } } +#else +# define DEBUGLOG(l, ...) {} /* disabled */ +#endif + +static int LZ4_isAligned(const void* ptr, size_t alignment) +{ + return ((size_t)ptr & (alignment -1)) == 0; +} + + +/*-************************************ +* Types +**************************************/ +#include <limits.h> +#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) +# include <stdint.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; +#else +# if UINT_MAX != 4294967295UL +# error "LZ4 code (when not C++ or C99) assumes that sizeof(int) == 4" +# endif + typedef unsigned char BYTE; + typedef unsigned short U16; + typedef unsigned int U32; + typedef signed int S32; + typedef unsigned long long U64; + typedef size_t uptrval; /* generally true, except OpenVMS-64 */ +#endif + +#if defined(__x86_64__) + typedef U64 reg_t; /* 64-bits in x32 mode */ +#else + typedef size_t reg_t; /* 32-bits in x32 mode */ +#endif + +typedef enum { + notLimited = 0, + limitedOutput = 1, + fillOutput = 2 +} limitedOutput_directive; + + +/*-************************************ +* Reading and writing into memory +**************************************/ + +/** + * LZ4 relies on memcpy with a constant size being inlined. In freestanding + * environments, the compiler can't assume the implementation of memcpy() is + * standard compliant, so it can't apply its specialized memcpy() inlining + * logic. When possible, use __builtin_memcpy() to tell the compiler to analyze + * memcpy() as if it were standard compliant, so it can inline it in freestanding + * environments. This is needed when decompressing the Linux Kernel, for example. + */ +#if !defined(LZ4_memcpy) +# if defined(__GNUC__) && (__GNUC__ >= 4) +# define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size) +# else +# define LZ4_memcpy(dst, src, size) memcpy(dst, src, size) +# endif +#endif + +#if !defined(LZ4_memmove) +# if defined(__GNUC__) && (__GNUC__ >= 4) +# define LZ4_memmove __builtin_memmove +# else +# define LZ4_memmove memmove +# endif +#endif + +static unsigned LZ4_isLittleEndian(void) +{ + const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ + return one.c[0]; +} + +#if defined(__GNUC__) || defined(__INTEL_COMPILER) +#define LZ4_PACK( __Declaration__ ) __Declaration__ __attribute__((__packed__)) +#elif defined(_MSC_VER) +#define LZ4_PACK( __Declaration__ ) __pragma( pack(push, 1) ) __Declaration__ __pragma( pack(pop)) +#endif + +#if defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==2) +/* lie to the compiler about data alignment; use with caution */ + +static U16 LZ4_read16(const void* memPtr) { return *(const U16*) memPtr; } +static U32 LZ4_read32(const void* memPtr) { return *(const U32*) memPtr; } +static reg_t LZ4_read_ARCH(const void* memPtr) { return *(const reg_t*) memPtr; } + +static void LZ4_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; } +static void LZ4_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; } + +#elif defined(LZ4_FORCE_MEMORY_ACCESS) && (LZ4_FORCE_MEMORY_ACCESS==1) + +/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */ +/* currently only defined for gcc and icc */ +LZ4_PACK(typedef struct { U16 u16; }) LZ4_unalign16; +LZ4_PACK(typedef struct { U32 u32; }) LZ4_unalign32; +LZ4_PACK(typedef struct { reg_t uArch; }) LZ4_unalignST; + +static U16 LZ4_read16(const void* ptr) { return ((const LZ4_unalign16*)ptr)->u16; } +static U32 LZ4_read32(const void* ptr) { return ((const LZ4_unalign32*)ptr)->u32; } +static reg_t LZ4_read_ARCH(const void* ptr) { return ((const LZ4_unalignST*)ptr)->uArch; } + +static void LZ4_write16(void* memPtr, U16 value) { ((LZ4_unalign16*)memPtr)->u16 = value; } +static void LZ4_write32(void* memPtr, U32 value) { ((LZ4_unalign32*)memPtr)->u32 = value; } + +#else /* safe and portable access using memcpy() */ + +static U16 LZ4_read16(const void* memPtr) +{ + U16 val; LZ4_memcpy(&val, memPtr, sizeof(val)); return val; +} + +static U32 LZ4_read32(const void* memPtr) +{ + U32 val; LZ4_memcpy(&val, memPtr, sizeof(val)); return val; +} + +static reg_t LZ4_read_ARCH(const void* memPtr) +{ + reg_t val; LZ4_memcpy(&val, memPtr, sizeof(val)); return val; +} + +static void LZ4_write16(void* memPtr, U16 value) +{ + LZ4_memcpy(memPtr, &value, sizeof(value)); +} + +static void LZ4_write32(void* memPtr, U32 value) +{ + LZ4_memcpy(memPtr, &value, sizeof(value)); +} + +#endif /* LZ4_FORCE_MEMORY_ACCESS */ + + +static U16 LZ4_readLE16(const void* memPtr) +{ + if (LZ4_isLittleEndian()) { + return LZ4_read16(memPtr); + } else { + const BYTE* p = (const BYTE*)memPtr; + return (U16)((U16)p[0] | (p[1]<<8)); + } +} + +#ifdef LZ4_STATIC_LINKING_ONLY_ENDIANNESS_INDEPENDENT_OUTPUT +static U32 LZ4_readLE32(const void* memPtr) +{ + if (LZ4_isLittleEndian()) { + return LZ4_read32(memPtr); + } else { + const BYTE* p = (const BYTE*)memPtr; + return (U32)p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24); + } +} +#endif + +static void LZ4_writeLE16(void* memPtr, U16 value) +{ + if (LZ4_isLittleEndian()) { + LZ4_write16(memPtr, value); + } else { + BYTE* p = (BYTE*)memPtr; + p[0] = (BYTE) value; + p[1] = (BYTE)(value>>8); + } +} + +/* customized variant of memcpy, which can overwrite up to 8 bytes beyond dstEnd */ +LZ4_FORCE_INLINE +void LZ4_wildCopy8(void* dstPtr, const void* srcPtr, void* dstEnd) +{ + BYTE* d = (BYTE*)dstPtr; + const BYTE* s = (const BYTE*)srcPtr; + BYTE* const e = (BYTE*)dstEnd; + + do { LZ4_memcpy(d,s,8); d+=8; s+=8; } while (d<e); +} + +static const unsigned inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4}; +static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3}; + + +#ifndef LZ4_FAST_DEC_LOOP +# if defined __i386__ || defined _M_IX86 || defined __x86_64__ || defined _M_X64 +# define LZ4_FAST_DEC_LOOP 1 +# elif defined(__aarch64__) && defined(__APPLE__) +# define LZ4_FAST_DEC_LOOP 1 +# elif defined(__aarch64__) && !defined(__clang__) + /* On non-Apple aarch64, we disable this optimization for clang because + * on certain mobile chipsets, performance is reduced with clang. For + * more information refer to https://github.com/lz4/lz4/pull/707 */ +# define LZ4_FAST_DEC_LOOP 1 +# else +# define LZ4_FAST_DEC_LOOP 0 +# endif +#endif + +#if LZ4_FAST_DEC_LOOP + +LZ4_FORCE_INLINE void +LZ4_memcpy_using_offset_base(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset) +{ + assert(srcPtr + offset == dstPtr); + if (offset < 8) { + LZ4_write32(dstPtr, 0); /* silence an msan warning when offset==0 */ + dstPtr[0] = srcPtr[0]; + dstPtr[1] = srcPtr[1]; + dstPtr[2] = srcPtr[2]; + dstPtr[3] = srcPtr[3]; + srcPtr += inc32table[offset]; + LZ4_memcpy(dstPtr+4, srcPtr, 4); + srcPtr -= dec64table[offset]; + dstPtr += 8; + } else { + LZ4_memcpy(dstPtr, srcPtr, 8); + dstPtr += 8; + srcPtr += 8; + } + + LZ4_wildCopy8(dstPtr, srcPtr, dstEnd); +} + +/* customized variant of memcpy, which can overwrite up to 32 bytes beyond dstEnd + * this version copies two times 16 bytes (instead of one time 32 bytes) + * because it must be compatible with offsets >= 16. */ +LZ4_FORCE_INLINE void +LZ4_wildCopy32(void* dstPtr, const void* srcPtr, void* dstEnd) +{ + BYTE* d = (BYTE*)dstPtr; + const BYTE* s = (const BYTE*)srcPtr; + BYTE* const e = (BYTE*)dstEnd; + + do { LZ4_memcpy(d,s,16); LZ4_memcpy(d+16,s+16,16); d+=32; s+=32; } while (d<e); +} + +/* LZ4_memcpy_using_offset() presumes : + * - dstEnd >= dstPtr + MINMATCH + * - there is at least 12 bytes available to write after dstEnd */ +LZ4_FORCE_INLINE void +LZ4_memcpy_using_offset(BYTE* dstPtr, const BYTE* srcPtr, BYTE* dstEnd, const size_t offset) +{ + BYTE v[8]; + + assert(dstEnd >= dstPtr + MINMATCH); + + switch(offset) { + case 1: + MEM_INIT(v, *srcPtr, 8); + break; + case 2: + LZ4_memcpy(v, srcPtr, 2); + LZ4_memcpy(&v[2], srcPtr, 2); +#if defined(_MSC_VER) && (_MSC_VER <= 1937) /* MSVC 2022 ver 17.7 or earlier */ +# pragma warning(push) +# pragma warning(disable : 6385) /* warning C6385: Reading invalid data from 'v'. */ +#endif + LZ4_memcpy(&v[4], v, 4); +#if defined(_MSC_VER) && (_MSC_VER <= 1937) /* MSVC 2022 ver 17.7 or earlier */ +# pragma warning(pop) +#endif + break; + case 4: + LZ4_memcpy(v, srcPtr, 4); + LZ4_memcpy(&v[4], srcPtr, 4); + break; + default: + LZ4_memcpy_using_offset_base(dstPtr, srcPtr, dstEnd, offset); + return; + } + + LZ4_memcpy(dstPtr, v, 8); + dstPtr += 8; + while (dstPtr < dstEnd) { + LZ4_memcpy(dstPtr, v, 8); + dstPtr += 8; + } +} +#endif + + +/*-************************************ +* Common functions +**************************************/ +static unsigned LZ4_NbCommonBytes (reg_t val) +{ + assert(val != 0); + if (LZ4_isLittleEndian()) { + if (sizeof(val) == 8) { +# if defined(_MSC_VER) && (_MSC_VER >= 1800) && (defined(_M_AMD64) && !defined(_M_ARM64EC)) && !defined(LZ4_FORCE_SW_BITCOUNT) +/*-************************************************************************************************* +* ARM64EC is a Microsoft-designed ARM64 ABI compatible with AMD64 applications on ARM64 Windows 11. +* The ARM64EC ABI does not support AVX/AVX2/AVX512 instructions, nor their relevant intrinsics +* including _tzcnt_u64. Therefore, we need to neuter the _tzcnt_u64 code path for ARM64EC. +****************************************************************************************************/ +# if defined(__clang__) && (__clang_major__ < 10) + /* Avoid undefined clang-cl intrinsics issue. + * See https://github.com/lz4/lz4/pull/1017 for details. */ + return (unsigned)__builtin_ia32_tzcnt_u64(val) >> 3; +# else + /* x64 CPUS without BMI support interpret `TZCNT` as `REP BSF` */ + return (unsigned)_tzcnt_u64(val) >> 3; +# endif +# elif defined(_MSC_VER) && defined(_WIN64) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r = 0; + _BitScanForward64(&r, (U64)val); + return (unsigned)r >> 3; +# elif (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \ + ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \ + !defined(LZ4_FORCE_SW_BITCOUNT) + return (unsigned)__builtin_ctzll((U64)val) >> 3; +# else + const U64 m = 0x0101010101010101ULL; + val ^= val - 1; + return (unsigned)(((U64)((val & (m - 1)) * m)) >> 56); +# endif + } else /* 32 bits */ { +# if defined(_MSC_VER) && (_MSC_VER >= 1400) && !defined(LZ4_FORCE_SW_BITCOUNT) + unsigned long r; + _BitScanForward(&r, (U32)val); + return (unsigned)r >> 3; +# elif (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \ + ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \ + !defined(__TINYC__) && !defined(LZ4_FORCE_SW_BITCOUNT) + return (unsigned)__builtin_ctz((U32)val) >> 3; +# else + const U32 m = 0x01010101; + return (unsigned)((((val - 1) ^ val) & (m - 1)) * m) >> 24; +# endif + } + } else /* Big Endian CPU */ { + if (sizeof(val)==8) { +# if (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \ + ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \ + !defined(__TINYC__) && !defined(LZ4_FORCE_SW_BITCOUNT) + return (unsigned)__builtin_clzll((U64)val) >> 3; +# else +#if 1 + /* this method is probably faster, + * but adds a 128 bytes lookup table */ + static const unsigned char ctz7_tab[128] = { + 7, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 6, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 5, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0, + }; + U64 const mask = 0x0101010101010101ULL; + U64 const t = (((val >> 8) - mask) | val) & mask; + return ctz7_tab[(t * 0x0080402010080402ULL) >> 57]; +#else + /* this method doesn't consume memory space like the previous one, + * but it contains several branches, + * that may end up slowing execution */ + static const U32 by32 = sizeof(val)*4; /* 32 on 64 bits (goal), 16 on 32 bits. + Just to avoid some static analyzer complaining about shift by 32 on 32-bits target. + Note that this code path is never triggered in 32-bits mode. */ + unsigned r; + if (!(val>>by32)) { r=4; } else { r=0; val>>=by32; } + if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; } + r += (!val); + return r; +#endif +# endif + } else /* 32 bits */ { +# if (defined(__clang__) || (defined(__GNUC__) && ((__GNUC__ > 3) || \ + ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))) && \ + !defined(LZ4_FORCE_SW_BITCOUNT) + return (unsigned)__builtin_clz((U32)val) >> 3; +# else + val >>= 8; + val = ((((val + 0x00FFFF00) | 0x00FFFFFF) + val) | + (val + 0x00FF0000)) >> 24; + return (unsigned)val ^ 3; +# endif + } + } +} + + +#define STEPSIZE sizeof(reg_t) +LZ4_FORCE_INLINE +unsigned LZ4_count(const BYTE* pIn, const BYTE* pMatch, const BYTE* pInLimit) +{ + const BYTE* const pStart = pIn; + + if (likely(pIn < pInLimit-(STEPSIZE-1))) { + reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn); + if (!diff) { + pIn+=STEPSIZE; pMatch+=STEPSIZE; + } else { + return LZ4_NbCommonBytes(diff); + } } + + while (likely(pIn < pInLimit-(STEPSIZE-1))) { + reg_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn); + if (!diff) { pIn+=STEPSIZE; pMatch+=STEPSIZE; continue; } + pIn += LZ4_NbCommonBytes(diff); + return (unsigned)(pIn - pStart); + } + + if ((STEPSIZE==8) && (pIn<(pInLimit-3)) && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { pIn+=4; pMatch+=4; } + if ((pIn<(pInLimit-1)) && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { pIn+=2; pMatch+=2; } + if ((pIn<pInLimit) && (*pMatch == *pIn)) pIn++; + return (unsigned)(pIn - pStart); +} + + +#ifndef LZ4_COMMONDEFS_ONLY +/*-************************************ +* Local Constants +**************************************/ +static const int LZ4_64Klimit = ((64 KB) + (MFLIMIT-1)); +static const U32 LZ4_skipTrigger = 6; /* Increase this value ==> compression run slower on incompressible data */ + + +/*-************************************ +* Local Structures and types +**************************************/ +typedef enum { clearedTable = 0, byPtr, byU32, byU16 } tableType_t; + +/** + * This enum distinguishes several different modes of accessing previous + * content in the stream. + * + * - noDict : There is no preceding content. + * - withPrefix64k : Table entries up to ctx->dictSize before the current blob + * blob being compressed are valid and refer to the preceding + * content (of length ctx->dictSize), which is available + * contiguously preceding in memory the content currently + * being compressed. + * - usingExtDict : Like withPrefix64k, but the preceding content is somewhere + * else in memory, starting at ctx->dictionary with length + * ctx->dictSize. + * - usingDictCtx : Everything concerning the preceding content is + * in a separate context, pointed to by ctx->dictCtx. + * ctx->dictionary, ctx->dictSize, and table entries + * in the current context that refer to positions + * preceding the beginning of the current compression are + * ignored. Instead, ctx->dictCtx->dictionary and ctx->dictCtx + * ->dictSize describe the location and size of the preceding + * content, and matches are found by looking in the ctx + * ->dictCtx->hashTable. + */ +typedef enum { noDict = 0, withPrefix64k, usingExtDict, usingDictCtx } dict_directive; +typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive; + + +/*-************************************ +* Local Utils +**************************************/ +int LZ4_versionNumber (void) { return LZ4_VERSION_NUMBER; } +const char* LZ4_versionString(void) { return LZ4_VERSION_STRING; } +int LZ4_compressBound(int isize) { return LZ4_COMPRESSBOUND(isize); } +int LZ4_sizeofState(void) { return sizeof(LZ4_stream_t); } + + +/*-**************************************** +* Internal Definitions, used only in Tests +*******************************************/ +#if defined (__cplusplus) +extern "C" { +#endif + +int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int srcSize); + +int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, + int compressedSize, int maxOutputSize, + const void* dictStart, size_t dictSize); +int LZ4_decompress_safe_partial_forceExtDict(const char* source, char* dest, + int compressedSize, int targetOutputSize, int dstCapacity, + const void* dictStart, size_t dictSize); +#if defined (__cplusplus) +} +#endif + +/*-****************************** +* Compression functions +********************************/ +LZ4_FORCE_INLINE U32 LZ4_hash4(U32 sequence, tableType_t const tableType) +{ + if (tableType == byU16) + return ((sequence * 2654435761U) >> ((MINMATCH*8)-(LZ4_HASHLOG+1))); + else + return ((sequence * 2654435761U) >> ((MINMATCH*8)-LZ4_HASHLOG)); +} + +LZ4_FORCE_INLINE U32 LZ4_hash5(U64 sequence, tableType_t const tableType) +{ + const U32 hashLog = (tableType == byU16) ? LZ4_HASHLOG+1 : LZ4_HASHLOG; + if (LZ4_isLittleEndian()) { + const U64 prime5bytes = 889523592379ULL; + return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog)); + } else { + const U64 prime8bytes = 11400714785074694791ULL; + return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog)); + } +} + +LZ4_FORCE_INLINE U32 LZ4_hashPosition(const void* const p, tableType_t const tableType) +{ + if ((sizeof(reg_t)==8) && (tableType != byU16)) return LZ4_hash5(LZ4_read_ARCH(p), tableType); + +#ifdef LZ4_STATIC_LINKING_ONLY_ENDIANNESS_INDEPENDENT_OUTPUT + return LZ4_hash4(LZ4_readLE32(p), tableType); +#else + return LZ4_hash4(LZ4_read32(p), tableType); +#endif +} + +LZ4_FORCE_INLINE void LZ4_clearHash(U32 h, void* tableBase, tableType_t const tableType) +{ + switch (tableType) + { + default: /* fallthrough */ + case clearedTable: { /* illegal! */ assert(0); return; } + case byPtr: { const BYTE** hashTable = (const BYTE**)tableBase; hashTable[h] = NULL; return; } + case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = 0; return; } + case byU16: { U16* hashTable = (U16*) tableBase; hashTable[h] = 0; return; } + } +} + +LZ4_FORCE_INLINE void LZ4_putIndexOnHash(U32 idx, U32 h, void* tableBase, tableType_t const tableType) +{ + switch (tableType) + { + default: /* fallthrough */ + case clearedTable: /* fallthrough */ + case byPtr: { /* illegal! */ assert(0); return; } + case byU32: { U32* hashTable = (U32*) tableBase; hashTable[h] = idx; return; } + case byU16: { U16* hashTable = (U16*) tableBase; assert(idx < 65536); hashTable[h] = (U16)idx; return; } + } +} + +/* LZ4_putPosition*() : only used in byPtr mode */ +LZ4_FORCE_INLINE void LZ4_putPositionOnHash(const BYTE* p, U32 h, + void* tableBase, tableType_t const tableType) +{ + const BYTE** const hashTable = (const BYTE**)tableBase; + assert(tableType == byPtr); (void)tableType; + hashTable[h] = p; +} + +LZ4_FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_t tableType) +{ + U32 const h = LZ4_hashPosition(p, tableType); + LZ4_putPositionOnHash(p, h, tableBase, tableType); +} + +/* LZ4_getIndexOnHash() : + * Index of match position registered in hash table. + * hash position must be calculated by using base+index, or dictBase+index. + * Assumption 1 : only valid if tableType == byU32 or byU16. + * Assumption 2 : h is presumed valid (within limits of hash table) + */ +LZ4_FORCE_INLINE U32 LZ4_getIndexOnHash(U32 h, const void* tableBase, tableType_t tableType) +{ + LZ4_STATIC_ASSERT(LZ4_MEMORY_USAGE > 2); + if (tableType == byU32) { + const U32* const hashTable = (const U32*) tableBase; + assert(h < (1U << (LZ4_MEMORY_USAGE-2))); + return hashTable[h]; + } + if (tableType == byU16) { + const U16* const hashTable = (const U16*) tableBase; + assert(h < (1U << (LZ4_MEMORY_USAGE-1))); + return hashTable[h]; + } + assert(0); return 0; /* forbidden case */ +} + +static const BYTE* LZ4_getPositionOnHash(U32 h, const void* tableBase, tableType_t tableType) +{ + assert(tableType == byPtr); (void)tableType; + { const BYTE* const* hashTable = (const BYTE* const*) tableBase; return hashTable[h]; } +} + +LZ4_FORCE_INLINE const BYTE* +LZ4_getPosition(const BYTE* p, + const void* tableBase, tableType_t tableType) +{ + U32 const h = LZ4_hashPosition(p, tableType); + return LZ4_getPositionOnHash(h, tableBase, tableType); +} + +LZ4_FORCE_INLINE void +LZ4_prepareTable(LZ4_stream_t_internal* const cctx, + const int inputSize, + const tableType_t tableType) { + /* If the table hasn't been used, it's guaranteed to be zeroed out, and is + * therefore safe to use no matter what mode we're in. Otherwise, we figure + * out if it's safe to leave as is or whether it needs to be reset. + */ + if ((tableType_t)cctx->tableType != clearedTable) { + assert(inputSize >= 0); + if ((tableType_t)cctx->tableType != tableType + || ((tableType == byU16) && cctx->currentOffset + (unsigned)inputSize >= 0xFFFFU) + || ((tableType == byU32) && cctx->currentOffset > 1 GB) + || tableType == byPtr + || inputSize >= 4 KB) + { + DEBUGLOG(4, "LZ4_prepareTable: Resetting table in %p", cctx); + MEM_INIT(cctx->hashTable, 0, LZ4_HASHTABLESIZE); + cctx->currentOffset = 0; + cctx->tableType = (U32)clearedTable; + } else { + DEBUGLOG(4, "LZ4_prepareTable: Re-use hash table (no reset)"); + } + } + + /* Adding a gap, so all previous entries are > LZ4_DISTANCE_MAX back, + * is faster than compressing without a gap. + * However, compressing with currentOffset == 0 is faster still, + * so we preserve that case. + */ + if (cctx->currentOffset != 0 && tableType == byU32) { + DEBUGLOG(5, "LZ4_prepareTable: adding 64KB to currentOffset"); + cctx->currentOffset += 64 KB; + } + + /* Finally, clear history */ + cctx->dictCtx = NULL; + cctx->dictionary = NULL; + cctx->dictSize = 0; +} + +/** LZ4_compress_generic_validated() : + * inlined, to ensure branches are decided at compilation time. + * The following conditions are presumed already validated: + * - source != NULL + * - inputSize > 0 + */ +LZ4_FORCE_INLINE int LZ4_compress_generic_validated( + LZ4_stream_t_internal* const cctx, + const char* const source, + char* const dest, + const int inputSize, + int* inputConsumed, /* only written when outputDirective == fillOutput */ + const int maxOutputSize, + const limitedOutput_directive outputDirective, + const tableType_t tableType, + const dict_directive dictDirective, + const dictIssue_directive dictIssue, + const int acceleration) +{ + int result; + const BYTE* ip = (const BYTE*)source; + + U32 const startIndex = cctx->currentOffset; + const BYTE* base = (const BYTE*)source - startIndex; + const BYTE* lowLimit; + + const LZ4_stream_t_internal* dictCtx = (const LZ4_stream_t_internal*) cctx->dictCtx; + const BYTE* const dictionary = + dictDirective == usingDictCtx ? dictCtx->dictionary : cctx->dictionary; + const U32 dictSize = + dictDirective == usingDictCtx ? dictCtx->dictSize : cctx->dictSize; + const U32 dictDelta = + (dictDirective == usingDictCtx) ? startIndex - dictCtx->currentOffset : 0; /* make indexes in dictCtx comparable with indexes in current context */ + + int const maybe_extMem = (dictDirective == usingExtDict) || (dictDirective == usingDictCtx); + U32 const prefixIdxLimit = startIndex - dictSize; /* used when dictDirective == dictSmall */ + const BYTE* const dictEnd = dictionary ? dictionary + dictSize : dictionary; + const BYTE* anchor = (const BYTE*) source; + const BYTE* const iend = ip + inputSize; + const BYTE* const mflimitPlusOne = iend - MFLIMIT + 1; + const BYTE* const matchlimit = iend - LASTLITERALS; + + /* the dictCtx currentOffset is indexed on the start of the dictionary, + * while a dictionary in the current context precedes the currentOffset */ + const BYTE* dictBase = (dictionary == NULL) ? NULL : + (dictDirective == usingDictCtx) ? + dictionary + dictSize - dictCtx->currentOffset : + dictionary + dictSize - startIndex; + + BYTE* op = (BYTE*) dest; + BYTE* const olimit = op + maxOutputSize; + + U32 offset = 0; + U32 forwardH; + + DEBUGLOG(5, "LZ4_compress_generic_validated: srcSize=%i, tableType=%u", inputSize, tableType); + assert(ip != NULL); + if (tableType == byU16) assert(inputSize<LZ4_64Klimit); /* Size too large (not within 64K limit) */ + if (tableType == byPtr) assert(dictDirective==noDict); /* only supported use case with byPtr */ + /* If init conditions are not met, we don't have to mark stream + * as having dirty context, since no action was taken yet */ + if (outputDirective == fillOutput && maxOutputSize < 1) { return 0; } /* Impossible to store anything */ + assert(acceleration >= 1); + + lowLimit = (const BYTE*)source - (dictDirective == withPrefix64k ? dictSize : 0); + + /* Update context state */ + if (dictDirective == usingDictCtx) { + /* Subsequent linked blocks can't use the dictionary. */ + /* Instead, they use the block we just compressed. */ + cctx->dictCtx = NULL; + cctx->dictSize = (U32)inputSize; + } else { + cctx->dictSize += (U32)inputSize; + } + cctx->currentOffset += (U32)inputSize; + cctx->tableType = (U32)tableType; + + if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */ + + /* First Byte */ + { U32 const h = LZ4_hashPosition(ip, tableType); + if (tableType == byPtr) { + LZ4_putPositionOnHash(ip, h, cctx->hashTable, byPtr); + } else { + LZ4_putIndexOnHash(startIndex, h, cctx->hashTable, tableType); + } } + ip++; forwardH = LZ4_hashPosition(ip, tableType); + + /* Main Loop */ + for ( ; ; ) { + const BYTE* match; + BYTE* token; + const BYTE* filledIp; + + /* Find a match */ + if (tableType == byPtr) { + const BYTE* forwardIp = ip; + int step = 1; + int searchMatchNb = acceleration << LZ4_skipTrigger; + do { + U32 const h = forwardH; + ip = forwardIp; + forwardIp += step; + step = (searchMatchNb++ >> LZ4_skipTrigger); + + if (unlikely(forwardIp > mflimitPlusOne)) goto _last_literals; + assert(ip < mflimitPlusOne); + + match = LZ4_getPositionOnHash(h, cctx->hashTable, tableType); + forwardH = LZ4_hashPosition(forwardIp, tableType); + LZ4_putPositionOnHash(ip, h, cctx->hashTable, tableType); + + } while ( (match+LZ4_DISTANCE_MAX < ip) + || (LZ4_read32(match) != LZ4_read32(ip)) ); + + } else { /* byU32, byU16 */ + + const BYTE* forwardIp = ip; + int step = 1; + int searchMatchNb = acceleration << LZ4_skipTrigger; + do { + U32 const h = forwardH; + U32 const current = (U32)(forwardIp - base); + U32 matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType); + assert(matchIndex <= current); + assert(forwardIp - base < (ptrdiff_t)(2 GB - 1)); + ip = forwardIp; + forwardIp += step; + step = (searchMatchNb++ >> LZ4_skipTrigger); + + if (unlikely(forwardIp > mflimitPlusOne)) goto _last_literals; + assert(ip < mflimitPlusOne); + + if (dictDirective == usingDictCtx) { + if (matchIndex < startIndex) { + /* there was no match, try the dictionary */ + assert(tableType == byU32); + matchIndex = LZ4_getIndexOnHash(h, dictCtx->hashTable, byU32); + match = dictBase + matchIndex; + matchIndex += dictDelta; /* make dictCtx index comparable with current context */ + lowLimit = dictionary; + } else { + match = base + matchIndex; + lowLimit = (const BYTE*)source; + } + } else if (dictDirective == usingExtDict) { + if (matchIndex < startIndex) { + DEBUGLOG(7, "extDict candidate: matchIndex=%5u < startIndex=%5u", matchIndex, startIndex); + assert(startIndex - matchIndex >= MINMATCH); + assert(dictBase); + match = dictBase + matchIndex; + lowLimit = dictionary; + } else { + match = base + matchIndex; + lowLimit = (const BYTE*)source; + } + } else { /* single continuous memory segment */ + match = base + matchIndex; + } + forwardH = LZ4_hashPosition(forwardIp, tableType); + LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType); + + DEBUGLOG(7, "candidate at pos=%u (offset=%u \n", matchIndex, current - matchIndex); + if ((dictIssue == dictSmall) && (matchIndex < prefixIdxLimit)) { continue; } /* match outside of valid area */ + assert(matchIndex < current); + if ( ((tableType != byU16) || (LZ4_DISTANCE_MAX < LZ4_DISTANCE_ABSOLUTE_MAX)) + && (matchIndex+LZ4_DISTANCE_MAX < current)) { + continue; + } /* too far */ + assert((current - matchIndex) <= LZ4_DISTANCE_MAX); /* match now expected within distance */ + + if (LZ4_read32(match) == LZ4_read32(ip)) { + if (maybe_extMem) offset = current - matchIndex; + break; /* match found */ + } + + } while(1); + } + + /* Catch up */ + filledIp = ip; + assert(ip > anchor); /* this is always true as ip has been advanced before entering the main loop */ + if ((match > lowLimit) && unlikely(ip[-1] == match[-1])) { + do { ip--; match--; } while (((ip > anchor) & (match > lowLimit)) && (unlikely(ip[-1] == match[-1]))); + } + + /* Encode Literals */ + { unsigned const litLength = (unsigned)(ip - anchor); + token = op++; + if ((outputDirective == limitedOutput) && /* Check output buffer overflow */ + (unlikely(op + litLength + (2 + 1 + LASTLITERALS) + (litLength/255) > olimit)) ) { + return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */ + } + if ((outputDirective == fillOutput) && + (unlikely(op + (litLength+240)/255 /* litlen */ + litLength /* literals */ + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit))) { + op--; + goto _last_literals; + } + if (litLength >= RUN_MASK) { + unsigned len = litLength - RUN_MASK; + *token = (RUN_MASK<<ML_BITS); + for(; len >= 255 ; len-=255) *op++ = 255; + *op++ = (BYTE)len; + } + else *token = (BYTE)(litLength<<ML_BITS); + + /* Copy Literals */ + LZ4_wildCopy8(op, anchor, op+litLength); + op+=litLength; + DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i", + (int)(anchor-(const BYTE*)source), litLength, (int)(ip-(const BYTE*)source)); + } + +_next_match: + /* at this stage, the following variables must be correctly set : + * - ip : at start of LZ operation + * - match : at start of previous pattern occurrence; can be within current prefix, or within extDict + * - offset : if maybe_ext_memSegment==1 (constant) + * - lowLimit : must be == dictionary to mean "match is within extDict"; must be == source otherwise + * - token and *token : position to write 4-bits for match length; higher 4-bits for literal length supposed already written + */ + + if ((outputDirective == fillOutput) && + (op + 2 /* offset */ + 1 /* token */ + MFLIMIT - MINMATCH /* min last literals so last match is <= end - MFLIMIT */ > olimit)) { + /* the match was too close to the end, rewind and go to last literals */ + op = token; + goto _last_literals; + } + + /* Encode Offset */ + if (maybe_extMem) { /* static test */ + DEBUGLOG(6, " with offset=%u (ext if > %i)", offset, (int)(ip - (const BYTE*)source)); + assert(offset <= LZ4_DISTANCE_MAX && offset > 0); + LZ4_writeLE16(op, (U16)offset); op+=2; + } else { + DEBUGLOG(6, " with offset=%u (same segment)", (U32)(ip - match)); + assert(ip-match <= LZ4_DISTANCE_MAX); + LZ4_writeLE16(op, (U16)(ip - match)); op+=2; + } + + /* Encode MatchLength */ + { unsigned matchCode; + + if ( (dictDirective==usingExtDict || dictDirective==usingDictCtx) + && (lowLimit==dictionary) /* match within extDict */ ) { + const BYTE* limit = ip + (dictEnd-match); + assert(dictEnd > match); + if (limit > matchlimit) limit = matchlimit; + matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, limit); + ip += (size_t)matchCode + MINMATCH; + if (ip==limit) { + unsigned const more = LZ4_count(limit, (const BYTE*)source, matchlimit); + matchCode += more; + ip += more; + } + DEBUGLOG(6, " with matchLength=%u starting in extDict", matchCode+MINMATCH); + } else { + matchCode = LZ4_count(ip+MINMATCH, match+MINMATCH, matchlimit); + ip += (size_t)matchCode + MINMATCH; + DEBUGLOG(6, " with matchLength=%u", matchCode+MINMATCH); + } + + if ((outputDirective) && /* Check output buffer overflow */ + (unlikely(op + (1 + LASTLITERALS) + (matchCode+240)/255 > olimit)) ) { + if (outputDirective == fillOutput) { + /* Match description too long : reduce it */ + U32 newMatchCode = 15 /* in token */ - 1 /* to avoid needing a zero byte */ + ((U32)(olimit - op) - 1 - LASTLITERALS) * 255; + ip -= matchCode - newMatchCode; + assert(newMatchCode < matchCode); + matchCode = newMatchCode; + if (unlikely(ip <= filledIp)) { + /* We have already filled up to filledIp so if ip ends up less than filledIp + * we have positions in the hash table beyond the current position. This is + * a problem if we reuse the hash table. So we have to remove these positions + * from the hash table. + */ + const BYTE* ptr; + DEBUGLOG(5, "Clearing %u positions", (U32)(filledIp - ip)); + for (ptr = ip; ptr <= filledIp; ++ptr) { + U32 const h = LZ4_hashPosition(ptr, tableType); + LZ4_clearHash(h, cctx->hashTable, tableType); + } + } + } else { + assert(outputDirective == limitedOutput); + return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */ + } + } + if (matchCode >= ML_MASK) { + *token += ML_MASK; + matchCode -= ML_MASK; + LZ4_write32(op, 0xFFFFFFFF); + while (matchCode >= 4*255) { + op+=4; + LZ4_write32(op, 0xFFFFFFFF); + matchCode -= 4*255; + } + op += matchCode / 255; + *op++ = (BYTE)(matchCode % 255); + } else + *token += (BYTE)(matchCode); + } + /* Ensure we have enough space for the last literals. */ + assert(!(outputDirective == fillOutput && op + 1 + LASTLITERALS > olimit)); + + anchor = ip; + + /* Test end of chunk */ + if (ip >= mflimitPlusOne) break; + + /* Fill table */ + { U32 const h = LZ4_hashPosition(ip-2, tableType); + if (tableType == byPtr) { + LZ4_putPositionOnHash(ip-2, h, cctx->hashTable, byPtr); + } else { + U32 const idx = (U32)((ip-2) - base); + LZ4_putIndexOnHash(idx, h, cctx->hashTable, tableType); + } } + + /* Test next position */ + if (tableType == byPtr) { + + match = LZ4_getPosition(ip, cctx->hashTable, tableType); + LZ4_putPosition(ip, cctx->hashTable, tableType); + if ( (match+LZ4_DISTANCE_MAX >= ip) + && (LZ4_read32(match) == LZ4_read32(ip)) ) + { token=op++; *token=0; goto _next_match; } + + } else { /* byU32, byU16 */ + + U32 const h = LZ4_hashPosition(ip, tableType); + U32 const current = (U32)(ip-base); + U32 matchIndex = LZ4_getIndexOnHash(h, cctx->hashTable, tableType); + assert(matchIndex < current); + if (dictDirective == usingDictCtx) { + if (matchIndex < startIndex) { + /* there was no match, try the dictionary */ + assert(tableType == byU32); + matchIndex = LZ4_getIndexOnHash(h, dictCtx->hashTable, byU32); + match = dictBase + matchIndex; + lowLimit = dictionary; /* required for match length counter */ + matchIndex += dictDelta; + } else { + match = base + matchIndex; + lowLimit = (const BYTE*)source; /* required for match length counter */ + } + } else if (dictDirective==usingExtDict) { + if (matchIndex < startIndex) { + assert(dictBase); + match = dictBase + matchIndex; + lowLimit = dictionary; /* required for match length counter */ + } else { + match = base + matchIndex; + lowLimit = (const BYTE*)source; /* required for match length counter */ + } + } else { /* single memory segment */ + match = base + matchIndex; + } + LZ4_putIndexOnHash(current, h, cctx->hashTable, tableType); + assert(matchIndex < current); + if ( ((dictIssue==dictSmall) ? (matchIndex >= prefixIdxLimit) : 1) + && (((tableType==byU16) && (LZ4_DISTANCE_MAX == LZ4_DISTANCE_ABSOLUTE_MAX)) ? 1 : (matchIndex+LZ4_DISTANCE_MAX >= current)) + && (LZ4_read32(match) == LZ4_read32(ip)) ) { + token=op++; + *token=0; + if (maybe_extMem) offset = current - matchIndex; + DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i", + (int)(anchor-(const BYTE*)source), 0, (int)(ip-(const BYTE*)source)); + goto _next_match; + } + } + + /* Prepare next loop */ + forwardH = LZ4_hashPosition(++ip, tableType); + + } + +_last_literals: + /* Encode Last Literals */ + { size_t lastRun = (size_t)(iend - anchor); + if ( (outputDirective) && /* Check output buffer overflow */ + (op + lastRun + 1 + ((lastRun+255-RUN_MASK)/255) > olimit)) { + if (outputDirective == fillOutput) { + /* adapt lastRun to fill 'dst' */ + assert(olimit >= op); + lastRun = (size_t)(olimit-op) - 1/*token*/; + lastRun -= (lastRun + 256 - RUN_MASK) / 256; /*additional length tokens*/ + } else { + assert(outputDirective == limitedOutput); + return 0; /* cannot compress within `dst` budget. Stored indexes in hash table are nonetheless fine */ + } + } + DEBUGLOG(6, "Final literal run : %i literals", (int)lastRun); + if (lastRun >= RUN_MASK) { + size_t accumulator = lastRun - RUN_MASK; + *op++ = RUN_MASK << ML_BITS; + for(; accumulator >= 255 ; accumulator-=255) *op++ = 255; + *op++ = (BYTE) accumulator; + } else { + *op++ = (BYTE)(lastRun<<ML_BITS); + } + LZ4_memcpy(op, anchor, lastRun); + ip = anchor + lastRun; + op += lastRun; + } + + if (outputDirective == fillOutput) { + *inputConsumed = (int) (((const char*)ip)-source); + } + result = (int)(((char*)op) - dest); + assert(result > 0); + DEBUGLOG(5, "LZ4_compress_generic: compressed %i bytes into %i bytes", inputSize, result); + return result; +} + +/** LZ4_compress_generic() : + * inlined, to ensure branches are decided at compilation time; + * takes care of src == (NULL, 0) + * and forward the rest to LZ4_compress_generic_validated */ +LZ4_FORCE_INLINE int LZ4_compress_generic( + LZ4_stream_t_internal* const cctx, + const char* const src, + char* const dst, + const int srcSize, + int *inputConsumed, /* only written when outputDirective == fillOutput */ + const int dstCapacity, + const limitedOutput_directive outputDirective, + const tableType_t tableType, + const dict_directive dictDirective, + const dictIssue_directive dictIssue, + const int acceleration) +{ + DEBUGLOG(5, "LZ4_compress_generic: srcSize=%i, dstCapacity=%i", + srcSize, dstCapacity); + + if ((U32)srcSize > (U32)LZ4_MAX_INPUT_SIZE) { return 0; } /* Unsupported srcSize, too large (or negative) */ + if (srcSize == 0) { /* src == NULL supported if srcSize == 0 */ + if (outputDirective != notLimited && dstCapacity <= 0) return 0; /* no output, can't write anything */ + DEBUGLOG(5, "Generating an empty block"); + assert(outputDirective == notLimited || dstCapacity >= 1); + assert(dst != NULL); + dst[0] = 0; + if (outputDirective == fillOutput) { + assert (inputConsumed != NULL); + *inputConsumed = 0; + } + return 1; + } + assert(src != NULL); + + return LZ4_compress_generic_validated(cctx, src, dst, srcSize, + inputConsumed, /* only written into if outputDirective == fillOutput */ + dstCapacity, outputDirective, + tableType, dictDirective, dictIssue, acceleration); +} + + +int LZ4_compress_fast_extState(void* state, const char* source, char* dest, int inputSize, int maxOutputSize, int acceleration) +{ + LZ4_stream_t_internal* const ctx = & LZ4_initStream(state, sizeof(LZ4_stream_t)) -> internal_donotuse; + assert(ctx != NULL); + if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT; + if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX; + if (maxOutputSize >= LZ4_compressBound(inputSize)) { + if (inputSize < LZ4_64Klimit) { + return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, byU16, noDict, noDictIssue, acceleration); + } else { + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32; + return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration); + } + } else { + if (inputSize < LZ4_64Klimit) { + return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, byU16, noDict, noDictIssue, acceleration); + } else { + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)source > LZ4_DISTANCE_MAX)) ? byPtr : byU32; + return LZ4_compress_generic(ctx, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, noDict, noDictIssue, acceleration); + } + } +} + +/** + * LZ4_compress_fast_extState_fastReset() : + * A variant of LZ4_compress_fast_extState(). + * + * Using this variant avoids an expensive initialization step. It is only safe + * to call if the state buffer is known to be correctly initialized already + * (see comment in lz4.h on LZ4_resetStream_fast() for a definition of + * "correctly initialized"). + */ +int LZ4_compress_fast_extState_fastReset(void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration) +{ + LZ4_stream_t_internal* const ctx = &((LZ4_stream_t*)state)->internal_donotuse; + if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT; + if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX; + assert(ctx != NULL); + + if (dstCapacity >= LZ4_compressBound(srcSize)) { + if (srcSize < LZ4_64Klimit) { + const tableType_t tableType = byU16; + LZ4_prepareTable(ctx, srcSize, tableType); + if (ctx->currentOffset) { + return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, dictSmall, acceleration); + } else { + return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration); + } + } else { + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32; + LZ4_prepareTable(ctx, srcSize, tableType); + return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, 0, notLimited, tableType, noDict, noDictIssue, acceleration); + } + } else { + if (srcSize < LZ4_64Klimit) { + const tableType_t tableType = byU16; + LZ4_prepareTable(ctx, srcSize, tableType); + if (ctx->currentOffset) { + return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, dictSmall, acceleration); + } else { + return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration); + } + } else { + const tableType_t tableType = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32; + LZ4_prepareTable(ctx, srcSize, tableType); + return LZ4_compress_generic(ctx, src, dst, srcSize, NULL, dstCapacity, limitedOutput, tableType, noDict, noDictIssue, acceleration); + } + } +} + + +int LZ4_compress_fast(const char* src, char* dest, int srcSize, int dstCapacity, int acceleration) +{ + int result; +#if (LZ4_HEAPMODE) + LZ4_stream_t* const ctxPtr = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */ + if (ctxPtr == NULL) return 0; +#else + LZ4_stream_t ctx; + LZ4_stream_t* const ctxPtr = &ctx; +#endif + result = LZ4_compress_fast_extState(ctxPtr, src, dest, srcSize, dstCapacity, acceleration); + +#if (LZ4_HEAPMODE) + FREEMEM(ctxPtr); +#endif + return result; +} + + +int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity) +{ + return LZ4_compress_fast(src, dst, srcSize, dstCapacity, 1); +} + + +/* Note!: This function leaves the stream in an unclean/broken state! + * It is not safe to subsequently use the same state with a _fastReset() or + * _continue() call without resetting it. */ +static int LZ4_compress_destSize_extState_internal(LZ4_stream_t* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize, int acceleration) +{ + void* const s = LZ4_initStream(state, sizeof (*state)); + assert(s != NULL); (void)s; + + if (targetDstSize >= LZ4_compressBound(*srcSizePtr)) { /* compression success is guaranteed */ + return LZ4_compress_fast_extState(state, src, dst, *srcSizePtr, targetDstSize, acceleration); + } else { + if (*srcSizePtr < LZ4_64Klimit) { + return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, byU16, noDict, noDictIssue, acceleration); + } else { + tableType_t const addrMode = ((sizeof(void*)==4) && ((uptrval)src > LZ4_DISTANCE_MAX)) ? byPtr : byU32; + return LZ4_compress_generic(&state->internal_donotuse, src, dst, *srcSizePtr, srcSizePtr, targetDstSize, fillOutput, addrMode, noDict, noDictIssue, acceleration); + } } +} + +int LZ4_compress_destSize_extState(void* state, const char* src, char* dst, int* srcSizePtr, int targetDstSize, int acceleration) +{ + int const r = LZ4_compress_destSize_extState_internal((LZ4_stream_t*)state, src, dst, srcSizePtr, targetDstSize, acceleration); + /* clean the state on exit */ + LZ4_initStream(state, sizeof (LZ4_stream_t)); + return r; +} + + +int LZ4_compress_destSize(const char* src, char* dst, int* srcSizePtr, int targetDstSize) +{ +#if (LZ4_HEAPMODE) + LZ4_stream_t* const ctx = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); /* malloc-calloc always properly aligned */ + if (ctx == NULL) return 0; +#else + LZ4_stream_t ctxBody; + LZ4_stream_t* const ctx = &ctxBody; +#endif + + int result = LZ4_compress_destSize_extState_internal(ctx, src, dst, srcSizePtr, targetDstSize, 1); + +#if (LZ4_HEAPMODE) + FREEMEM(ctx); +#endif + return result; +} + + + +/*-****************************** +* Streaming functions +********************************/ + +#if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) +LZ4_stream_t* LZ4_createStream(void) +{ + LZ4_stream_t* const lz4s = (LZ4_stream_t*)ALLOC(sizeof(LZ4_stream_t)); + LZ4_STATIC_ASSERT(sizeof(LZ4_stream_t) >= sizeof(LZ4_stream_t_internal)); + DEBUGLOG(4, "LZ4_createStream %p", lz4s); + if (lz4s == NULL) return NULL; + LZ4_initStream(lz4s, sizeof(*lz4s)); + return lz4s; +} +#endif + +static size_t LZ4_stream_t_alignment(void) +{ +#if LZ4_ALIGN_TEST + typedef struct { char c; LZ4_stream_t t; } t_a; + return sizeof(t_a) - sizeof(LZ4_stream_t); +#else + return 1; /* effectively disabled */ +#endif +} + +LZ4_stream_t* LZ4_initStream (void* buffer, size_t size) +{ + DEBUGLOG(5, "LZ4_initStream"); + if (buffer == NULL) { return NULL; } + if (size < sizeof(LZ4_stream_t)) { return NULL; } + if (!LZ4_isAligned(buffer, LZ4_stream_t_alignment())) return NULL; + MEM_INIT(buffer, 0, sizeof(LZ4_stream_t_internal)); + return (LZ4_stream_t*)buffer; +} + +/* resetStream is now deprecated, + * prefer initStream() which is more general */ +void LZ4_resetStream (LZ4_stream_t* LZ4_stream) +{ + DEBUGLOG(5, "LZ4_resetStream (ctx:%p)", LZ4_stream); + MEM_INIT(LZ4_stream, 0, sizeof(LZ4_stream_t_internal)); +} + +void LZ4_resetStream_fast(LZ4_stream_t* ctx) { + LZ4_prepareTable(&(ctx->internal_donotuse), 0, byU32); +} + +#if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) +int LZ4_freeStream (LZ4_stream_t* LZ4_stream) +{ + if (!LZ4_stream) return 0; /* support free on NULL */ + DEBUGLOG(5, "LZ4_freeStream %p", LZ4_stream); + FREEMEM(LZ4_stream); + return (0); +} +#endif + + +typedef enum { _ld_fast, _ld_slow } LoadDict_mode_e; +#define HASH_UNIT sizeof(reg_t) +int LZ4_loadDict_internal(LZ4_stream_t* LZ4_dict, + const char* dictionary, int dictSize, + LoadDict_mode_e _ld) +{ + LZ4_stream_t_internal* const dict = &LZ4_dict->internal_donotuse; + const tableType_t tableType = byU32; + const BYTE* p = (const BYTE*)dictionary; + const BYTE* const dictEnd = p + dictSize; + U32 idx32; + + DEBUGLOG(4, "LZ4_loadDict (%i bytes from %p into %p)", dictSize, dictionary, LZ4_dict); + + /* It's necessary to reset the context, + * and not just continue it with prepareTable() + * to avoid any risk of generating overflowing matchIndex + * when compressing using this dictionary */ + LZ4_resetStream(LZ4_dict); + + /* We always increment the offset by 64 KB, since, if the dict is longer, + * we truncate it to the last 64k, and if it's shorter, we still want to + * advance by a whole window length so we can provide the guarantee that + * there are only valid offsets in the window, which allows an optimization + * in LZ4_compress_fast_continue() where it uses noDictIssue even when the + * dictionary isn't a full 64k. */ + dict->currentOffset += 64 KB; + + if (dictSize < (int)HASH_UNIT) { + return 0; + } + + if ((dictEnd - p) > 64 KB) p = dictEnd - 64 KB; + dict->dictionary = p; + dict->dictSize = (U32)(dictEnd - p); + dict->tableType = (U32)tableType; + idx32 = dict->currentOffset - dict->dictSize; + + while (p <= dictEnd-HASH_UNIT) { + U32 const h = LZ4_hashPosition(p, tableType); + /* Note: overwriting => favors positions end of dictionary */ + LZ4_putIndexOnHash(idx32, h, dict->hashTable, tableType); + p+=3; idx32+=3; + } + + if (_ld == _ld_slow) { + /* Fill hash table with additional references, to improve compression capability */ + p = dict->dictionary; + idx32 = dict->currentOffset - dict->dictSize; + while (p <= dictEnd-HASH_UNIT) { + U32 const h = LZ4_hashPosition(p, tableType); + U32 const limit = dict->currentOffset - 64 KB; + if (LZ4_getIndexOnHash(h, dict->hashTable, tableType) <= limit) { + /* Note: not overwriting => favors positions beginning of dictionary */ + LZ4_putIndexOnHash(idx32, h, dict->hashTable, tableType); + } + p++; idx32++; + } + } + + return (int)dict->dictSize; +} + +int LZ4_loadDict(LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize) +{ + return LZ4_loadDict_internal(LZ4_dict, dictionary, dictSize, _ld_fast); +} + +int LZ4_loadDictSlow(LZ4_stream_t* LZ4_dict, const char* dictionary, int dictSize) +{ + return LZ4_loadDict_internal(LZ4_dict, dictionary, dictSize, _ld_slow); +} + +void LZ4_attach_dictionary(LZ4_stream_t* workingStream, const LZ4_stream_t* dictionaryStream) +{ + const LZ4_stream_t_internal* dictCtx = (dictionaryStream == NULL) ? NULL : + &(dictionaryStream->internal_donotuse); + + DEBUGLOG(4, "LZ4_attach_dictionary (%p, %p, size %u)", + workingStream, dictionaryStream, + dictCtx != NULL ? dictCtx->dictSize : 0); + + if (dictCtx != NULL) { + /* If the current offset is zero, we will never look in the + * external dictionary context, since there is no value a table + * entry can take that indicate a miss. In that case, we need + * to bump the offset to something non-zero. + */ + if (workingStream->internal_donotuse.currentOffset == 0) { + workingStream->internal_donotuse.currentOffset = 64 KB; + } + + /* Don't actually attach an empty dictionary. + */ + if (dictCtx->dictSize == 0) { + dictCtx = NULL; + } + } + workingStream->internal_donotuse.dictCtx = dictCtx; +} + + +static void LZ4_renormDictT(LZ4_stream_t_internal* LZ4_dict, int nextSize) +{ + assert(nextSize >= 0); + if (LZ4_dict->currentOffset + (unsigned)nextSize > 0x80000000) { /* potential ptrdiff_t overflow (32-bits mode) */ + /* rescale hash table */ + U32 const delta = LZ4_dict->currentOffset - 64 KB; + const BYTE* dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize; + int i; + DEBUGLOG(4, "LZ4_renormDictT"); + for (i=0; i<LZ4_HASH_SIZE_U32; i++) { + if (LZ4_dict->hashTable[i] < delta) LZ4_dict->hashTable[i]=0; + else LZ4_dict->hashTable[i] -= delta; + } + LZ4_dict->currentOffset = 64 KB; + if (LZ4_dict->dictSize > 64 KB) LZ4_dict->dictSize = 64 KB; + LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize; + } +} + + +int LZ4_compress_fast_continue (LZ4_stream_t* LZ4_stream, + const char* source, char* dest, + int inputSize, int maxOutputSize, + int acceleration) +{ + const tableType_t tableType = byU32; + LZ4_stream_t_internal* const streamPtr = &LZ4_stream->internal_donotuse; + const char* dictEnd = streamPtr->dictSize ? (const char*)streamPtr->dictionary + streamPtr->dictSize : NULL; + + DEBUGLOG(5, "LZ4_compress_fast_continue (inputSize=%i, dictSize=%u)", inputSize, streamPtr->dictSize); + + LZ4_renormDictT(streamPtr, inputSize); /* fix index overflow */ + if (acceleration < 1) acceleration = LZ4_ACCELERATION_DEFAULT; + if (acceleration > LZ4_ACCELERATION_MAX) acceleration = LZ4_ACCELERATION_MAX; + + /* invalidate tiny dictionaries */ + if ( (streamPtr->dictSize < 4) /* tiny dictionary : not enough for a hash */ + && (dictEnd != source) /* prefix mode */ + && (inputSize > 0) /* tolerance : don't lose history, in case next invocation would use prefix mode */ + && (streamPtr->dictCtx == NULL) /* usingDictCtx */ + ) { + DEBUGLOG(5, "LZ4_compress_fast_continue: dictSize(%u) at addr:%p is too small", streamPtr->dictSize, streamPtr->dictionary); + /* remove dictionary existence from history, to employ faster prefix mode */ + streamPtr->dictSize = 0; + streamPtr->dictionary = (const BYTE*)source; + dictEnd = source; + } + + /* Check overlapping input/dictionary space */ + { const char* const sourceEnd = source + inputSize; + if ((sourceEnd > (const char*)streamPtr->dictionary) && (sourceEnd < dictEnd)) { + streamPtr->dictSize = (U32)(dictEnd - sourceEnd); + if (streamPtr->dictSize > 64 KB) streamPtr->dictSize = 64 KB; + if (streamPtr->dictSize < 4) streamPtr->dictSize = 0; + streamPtr->dictionary = (const BYTE*)dictEnd - streamPtr->dictSize; + } + } + + /* prefix mode : source data follows dictionary */ + if (dictEnd == source) { + if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) + return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, dictSmall, acceleration); + else + return LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, withPrefix64k, noDictIssue, acceleration); + } + + /* external dictionary mode */ + { int result; + if (streamPtr->dictCtx) { + /* We depend here on the fact that dictCtx'es (produced by + * LZ4_loadDict) guarantee that their tables contain no references + * to offsets between dictCtx->currentOffset - 64 KB and + * dictCtx->currentOffset - dictCtx->dictSize. This makes it safe + * to use noDictIssue even when the dict isn't a full 64 KB. + */ + if (inputSize > 4 KB) { + /* For compressing large blobs, it is faster to pay the setup + * cost to copy the dictionary's tables into the active context, + * so that the compression loop is only looking into one table. + */ + LZ4_memcpy(streamPtr, streamPtr->dictCtx, sizeof(*streamPtr)); + result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration); + } else { + result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingDictCtx, noDictIssue, acceleration); + } + } else { /* small data <= 4 KB */ + if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) { + result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, dictSmall, acceleration); + } else { + result = LZ4_compress_generic(streamPtr, source, dest, inputSize, NULL, maxOutputSize, limitedOutput, tableType, usingExtDict, noDictIssue, acceleration); + } + } + streamPtr->dictionary = (const BYTE*)source; + streamPtr->dictSize = (U32)inputSize; + return result; + } +} + + +/* Hidden debug function, to force-test external dictionary mode */ +int LZ4_compress_forceExtDict (LZ4_stream_t* LZ4_dict, const char* source, char* dest, int srcSize) +{ + LZ4_stream_t_internal* const streamPtr = &LZ4_dict->internal_donotuse; + int result; + + LZ4_renormDictT(streamPtr, srcSize); + + if ((streamPtr->dictSize < 64 KB) && (streamPtr->dictSize < streamPtr->currentOffset)) { + result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 0, notLimited, byU32, usingExtDict, dictSmall, 1); + } else { + result = LZ4_compress_generic(streamPtr, source, dest, srcSize, NULL, 0, notLimited, byU32, usingExtDict, noDictIssue, 1); + } + + streamPtr->dictionary = (const BYTE*)source; + streamPtr->dictSize = (U32)srcSize; + + return result; +} + + +/*! LZ4_saveDict() : + * If previously compressed data block is not guaranteed to remain available at its memory location, + * save it into a safer place (char* safeBuffer). + * Note : no need to call LZ4_loadDict() afterwards, dictionary is immediately usable, + * one can therefore call LZ4_compress_fast_continue() right after. + * @return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error. + */ +int LZ4_saveDict (LZ4_stream_t* LZ4_dict, char* safeBuffer, int dictSize) +{ + LZ4_stream_t_internal* const dict = &LZ4_dict->internal_donotuse; + + DEBUGLOG(5, "LZ4_saveDict : dictSize=%i, safeBuffer=%p", dictSize, safeBuffer); + + if ((U32)dictSize > 64 KB) { dictSize = 64 KB; } /* useless to define a dictionary > 64 KB */ + if ((U32)dictSize > dict->dictSize) { dictSize = (int)dict->dictSize; } + + if (safeBuffer == NULL) assert(dictSize == 0); + if (dictSize > 0) { + const BYTE* const previousDictEnd = dict->dictionary + dict->dictSize; + assert(dict->dictionary); + LZ4_memmove(safeBuffer, previousDictEnd - dictSize, (size_t)dictSize); + } + + dict->dictionary = (const BYTE*)safeBuffer; + dict->dictSize = (U32)dictSize; + + return dictSize; +} + + + +/*-******************************* + * Decompression functions + ********************************/ + +typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive; + +#undef MIN +#define MIN(a,b) ( (a) < (b) ? (a) : (b) ) + + +/* variant for decompress_unsafe() + * does not know end of input + * presumes input is well formed + * note : will consume at least one byte */ +static size_t read_long_length_no_check(const BYTE** pp) +{ + size_t b, l = 0; + do { b = **pp; (*pp)++; l += b; } while (b==255); + DEBUGLOG(6, "read_long_length_no_check: +length=%zu using %zu input bytes", l, l/255 + 1) + return l; +} + +/* core decoder variant for LZ4_decompress_fast*() + * for legacy support only : these entry points are deprecated. + * - Presumes input is correctly formed (no defense vs malformed inputs) + * - Does not know input size (presume input buffer is "large enough") + * - Decompress a full block (only) + * @return : nb of bytes read from input. + * Note : this variant is not optimized for speed, just for maintenance. + * the goal is to remove support of decompress_fast*() variants by v2.0 +**/ +LZ4_FORCE_INLINE int +LZ4_decompress_unsafe_generic( + const BYTE* const istart, + BYTE* const ostart, + int decompressedSize, + + size_t prefixSize, + const BYTE* const dictStart, /* only if dict==usingExtDict */ + const size_t dictSize /* note: =0 if dictStart==NULL */ + ) +{ + const BYTE* ip = istart; + BYTE* op = (BYTE*)ostart; + BYTE* const oend = ostart + decompressedSize; + const BYTE* const prefixStart = ostart - prefixSize; + + DEBUGLOG(5, "LZ4_decompress_unsafe_generic"); + if (dictStart == NULL) assert(dictSize == 0); + + while (1) { + /* start new sequence */ + unsigned token = *ip++; + + /* literals */ + { size_t ll = token >> ML_BITS; + if (ll==15) { + /* long literal length */ + ll += read_long_length_no_check(&ip); + } + if ((size_t)(oend-op) < ll) return -1; /* output buffer overflow */ + LZ4_memmove(op, ip, ll); /* support in-place decompression */ + op += ll; + ip += ll; + if ((size_t)(oend-op) < MFLIMIT) { + if (op==oend) break; /* end of block */ + DEBUGLOG(5, "invalid: literals end at distance %zi from end of block", oend-op); + /* incorrect end of block : + * last match must start at least MFLIMIT==12 bytes before end of output block */ + return -1; + } } + + /* match */ + { size_t ml = token & 15; + size_t const offset = LZ4_readLE16(ip); + ip+=2; + + if (ml==15) { + /* long literal length */ + ml += read_long_length_no_check(&ip); + } + ml += MINMATCH; + + if ((size_t)(oend-op) < ml) return -1; /* output buffer overflow */ + + { const BYTE* match = op - offset; + + /* out of range */ + if (offset > (size_t)(op - prefixStart) + dictSize) { + DEBUGLOG(6, "offset out of range"); + return -1; + } + + /* check special case : extDict */ + if (offset > (size_t)(op - prefixStart)) { + /* extDict scenario */ + const BYTE* const dictEnd = dictStart + dictSize; + const BYTE* extMatch = dictEnd - (offset - (size_t)(op-prefixStart)); + size_t const extml = (size_t)(dictEnd - extMatch); + if (extml > ml) { + /* match entirely within extDict */ + LZ4_memmove(op, extMatch, ml); + op += ml; + ml = 0; + } else { + /* match split between extDict & prefix */ + LZ4_memmove(op, extMatch, extml); + op += extml; + ml -= extml; + } + match = prefixStart; + } + + /* match copy - slow variant, supporting overlap copy */ + { size_t u; + for (u=0; u<ml; u++) { + op[u] = match[u]; + } } } + op += ml; + if ((size_t)(oend-op) < LASTLITERALS) { + DEBUGLOG(5, "invalid: match ends at distance %zi from end of block", oend-op); + /* incorrect end of block : + * last match must stop at least LASTLITERALS==5 bytes before end of output block */ + return -1; + } + } /* match */ + } /* main loop */ + return (int)(ip - istart); +} + + +/* Read the variable-length literal or match length. + * + * @ip : input pointer + * @ilimit : position after which if length is not decoded, the input is necessarily corrupted. + * @initial_check - check ip >= ipmax before start of loop. Returns initial_error if so. + * @error (output) - error code. Must be set to 0 before call. +**/ +typedef size_t Rvl_t; +static const Rvl_t rvl_error = (Rvl_t)(-1); +LZ4_FORCE_INLINE Rvl_t +read_variable_length(const BYTE** ip, const BYTE* ilimit, + int initial_check) +{ + Rvl_t s, length = 0; + assert(ip != NULL); + assert(*ip != NULL); + assert(ilimit != NULL); + if (initial_check && unlikely((*ip) >= ilimit)) { /* read limit reached */ + return rvl_error; + } + s = **ip; + (*ip)++; + length += s; + if (unlikely((*ip) > ilimit)) { /* read limit reached */ + return rvl_error; + } + /* accumulator overflow detection (32-bit mode only) */ + if ((sizeof(length) < 8) && unlikely(length > ((Rvl_t)(-1)/2)) ) { + return rvl_error; + } + if (likely(s != 255)) return length; + do { + s = **ip; + (*ip)++; + length += s; + if (unlikely((*ip) > ilimit)) { /* read limit reached */ + return rvl_error; + } + /* accumulator overflow detection (32-bit mode only) */ + if ((sizeof(length) < 8) && unlikely(length > ((Rvl_t)(-1)/2)) ) { + return rvl_error; + } + } while (s == 255); + + return length; +} + +/*! LZ4_decompress_generic() : + * This generic decompression function covers all use cases. + * It shall be instantiated several times, using different sets of directives. + * Note that it is important for performance that this function really get inlined, + * in order to remove useless branches during compilation optimization. + */ +LZ4_FORCE_INLINE int +LZ4_decompress_generic( + const char* const src, + char* const dst, + int srcSize, + int outputSize, /* If endOnInput==endOnInputSize, this value is `dstCapacity` */ + + earlyEnd_directive partialDecoding, /* full, partial */ + dict_directive dict, /* noDict, withPrefix64k, usingExtDict */ + const BYTE* const lowPrefix, /* always <= dst, == dst when no prefix */ + const BYTE* const dictStart, /* only if dict==usingExtDict */ + const size_t dictSize /* note : = 0 if noDict */ + ) +{ + if ((src == NULL) || (outputSize < 0)) { return -1; } + + { const BYTE* ip = (const BYTE*) src; + const BYTE* const iend = ip + srcSize; + + BYTE* op = (BYTE*) dst; + BYTE* const oend = op + outputSize; + BYTE* cpy; + + const BYTE* const dictEnd = (dictStart == NULL) ? NULL : dictStart + dictSize; + + const int checkOffset = (dictSize < (int)(64 KB)); + + + /* Set up the "end" pointers for the shortcut. */ + const BYTE* const shortiend = iend - 14 /*maxLL*/ - 2 /*offset*/; + const BYTE* const shortoend = oend - 14 /*maxLL*/ - 18 /*maxML*/; + + const BYTE* match; + size_t offset; + unsigned token; + size_t length; + + + DEBUGLOG(5, "LZ4_decompress_generic (srcSize:%i, dstSize:%i)", srcSize, outputSize); + + /* Special cases */ + assert(lowPrefix <= op); + if (unlikely(outputSize==0)) { + /* Empty output buffer */ + if (partialDecoding) return 0; + return ((srcSize==1) && (*ip==0)) ? 0 : -1; + } + if (unlikely(srcSize==0)) { return -1; } + + /* LZ4_FAST_DEC_LOOP: + * designed for modern OoO performance cpus, + * where copying reliably 32-bytes is preferable to an unpredictable branch. + * note : fast loop may show a regression for some client arm chips. */ +#if LZ4_FAST_DEC_LOOP + if ((oend - op) < FASTLOOP_SAFE_DISTANCE) { + DEBUGLOG(6, "move to safe decode loop"); + goto safe_decode; + } + + /* Fast loop : decode sequences as long as output < oend-FASTLOOP_SAFE_DISTANCE */ + DEBUGLOG(6, "using fast decode loop"); + while (1) { + /* Main fastloop assertion: We can always wildcopy FASTLOOP_SAFE_DISTANCE */ + assert(oend - op >= FASTLOOP_SAFE_DISTANCE); + assert(ip < iend); + token = *ip++; + length = token >> ML_BITS; /* literal length */ + DEBUGLOG(7, "blockPos%6u: litLength token = %u", (unsigned)(op-(BYTE*)dst), (unsigned)length); + + /* decode literal length */ + if (length == RUN_MASK) { + size_t const addl = read_variable_length(&ip, iend-RUN_MASK, 1); + if (addl == rvl_error) { + DEBUGLOG(6, "error reading long literal length"); + goto _output_error; + } + length += addl; + if (unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */ + if (unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */ + + /* copy literals */ + LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); + if ((op+length>oend-32) || (ip+length>iend-32)) { goto safe_literal_copy; } + LZ4_wildCopy32(op, ip, op+length); + ip += length; op += length; + } else if (ip <= iend-(16 + 1/*max lit + offset + nextToken*/)) { + /* We don't need to check oend, since we check it once for each loop below */ + DEBUGLOG(7, "copy %u bytes in a 16-bytes stripe", (unsigned)length); + /* Literals can only be <= 14, but hope compilers optimize better when copy by a register size */ + LZ4_memcpy(op, ip, 16); + ip += length; op += length; + } else { + goto safe_literal_copy; + } + + /* get offset */ + offset = LZ4_readLE16(ip); ip+=2; + DEBUGLOG(6, "blockPos%6u: offset = %u", (unsigned)(op-(BYTE*)dst), (unsigned)offset); + match = op - offset; + assert(match <= op); /* overflow check */ + + /* get matchlength */ + length = token & ML_MASK; + DEBUGLOG(7, " match length token = %u (len==%u)", (unsigned)length, (unsigned)length+MINMATCH); + + if (length == ML_MASK) { + size_t const addl = read_variable_length(&ip, iend - LASTLITERALS + 1, 0); + if (addl == rvl_error) { + DEBUGLOG(5, "error reading long match length"); + goto _output_error; + } + length += addl; + length += MINMATCH; + DEBUGLOG(7, " long match length == %u", (unsigned)length); + if (unlikely((uptrval)(op)+length<(uptrval)op)) { goto _output_error; } /* overflow detection */ + if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) { + goto safe_match_copy; + } + } else { + length += MINMATCH; + if (op + length >= oend - FASTLOOP_SAFE_DISTANCE) { + DEBUGLOG(7, "moving to safe_match_copy (ml==%u)", (unsigned)length); + goto safe_match_copy; + } + + /* Fastpath check: skip LZ4_wildCopy32 when true */ + if ((dict == withPrefix64k) || (match >= lowPrefix)) { + if (offset >= 8) { + assert(match >= lowPrefix); + assert(match <= op); + assert(op + 18 <= oend); + + LZ4_memcpy(op, match, 8); + LZ4_memcpy(op+8, match+8, 8); + LZ4_memcpy(op+16, match+16, 2); + op += length; + continue; + } } } + + if ( checkOffset && (unlikely(match + dictSize < lowPrefix)) ) { + DEBUGLOG(5, "Error : pos=%zi, offset=%zi => outside buffers", op-lowPrefix, op-match); + goto _output_error; + } + /* match starting within external dictionary */ + if ((dict==usingExtDict) && (match < lowPrefix)) { + assert(dictEnd != NULL); + if (unlikely(op+length > oend-LASTLITERALS)) { + if (partialDecoding) { + DEBUGLOG(7, "partialDecoding: dictionary match, close to dstEnd"); + length = MIN(length, (size_t)(oend-op)); + } else { + DEBUGLOG(6, "end-of-block condition violated") + goto _output_error; + } } + + if (length <= (size_t)(lowPrefix-match)) { + /* match fits entirely within external dictionary : just copy */ + LZ4_memmove(op, dictEnd - (lowPrefix-match), length); + op += length; + } else { + /* match stretches into both external dictionary and current block */ + size_t const copySize = (size_t)(lowPrefix - match); + size_t const restSize = length - copySize; + LZ4_memcpy(op, dictEnd - copySize, copySize); + op += copySize; + if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */ + BYTE* const endOfMatch = op + restSize; + const BYTE* copyFrom = lowPrefix; + while (op < endOfMatch) { *op++ = *copyFrom++; } + } else { + LZ4_memcpy(op, lowPrefix, restSize); + op += restSize; + } } + continue; + } + + /* copy match within block */ + cpy = op + length; + + assert((op <= oend) && (oend-op >= 32)); + if (unlikely(offset<16)) { + LZ4_memcpy_using_offset(op, match, cpy, offset); + } else { + LZ4_wildCopy32(op, match, cpy); + } + + op = cpy; /* wildcopy correction */ + } + safe_decode: +#endif + + /* Main Loop : decode remaining sequences where output < FASTLOOP_SAFE_DISTANCE */ + DEBUGLOG(6, "using safe decode loop"); + while (1) { + assert(ip < iend); + token = *ip++; + length = token >> ML_BITS; /* literal length */ + DEBUGLOG(7, "blockPos%6u: litLength token = %u", (unsigned)(op-(BYTE*)dst), (unsigned)length); + + /* A two-stage shortcut for the most common case: + * 1) If the literal length is 0..14, and there is enough space, + * enter the shortcut and copy 16 bytes on behalf of the literals + * (in the fast mode, only 8 bytes can be safely copied this way). + * 2) Further if the match length is 4..18, copy 18 bytes in a similar + * manner; but we ensure that there's enough space in the output for + * those 18 bytes earlier, upon entering the shortcut (in other words, + * there is a combined check for both stages). + */ + if ( (length != RUN_MASK) + /* strictly "less than" on input, to re-enter the loop with at least one byte */ + && likely((ip < shortiend) & (op <= shortoend)) ) { + /* Copy the literals */ + LZ4_memcpy(op, ip, 16); + op += length; ip += length; + + /* The second stage: prepare for match copying, decode full info. + * If it doesn't work out, the info won't be wasted. */ + length = token & ML_MASK; /* match length */ + DEBUGLOG(7, "blockPos%6u: matchLength token = %u (len=%u)", (unsigned)(op-(BYTE*)dst), (unsigned)length, (unsigned)length + 4); + offset = LZ4_readLE16(ip); ip += 2; + match = op - offset; + assert(match <= op); /* check overflow */ + + /* Do not deal with overlapping matches. */ + if ( (length != ML_MASK) + && (offset >= 8) + && (dict==withPrefix64k || match >= lowPrefix) ) { + /* Copy the match. */ + LZ4_memcpy(op + 0, match + 0, 8); + LZ4_memcpy(op + 8, match + 8, 8); + LZ4_memcpy(op +16, match +16, 2); + op += length + MINMATCH; + /* Both stages worked, load the next token. */ + continue; + } + + /* The second stage didn't work out, but the info is ready. + * Propel it right to the point of match copying. */ + goto _copy_match; + } + + /* decode literal length */ + if (length == RUN_MASK) { + size_t const addl = read_variable_length(&ip, iend-RUN_MASK, 1); + if (addl == rvl_error) { goto _output_error; } + length += addl; + if (unlikely((uptrval)(op)+length<(uptrval)(op))) { goto _output_error; } /* overflow detection */ + if (unlikely((uptrval)(ip)+length<(uptrval)(ip))) { goto _output_error; } /* overflow detection */ + } + +#if LZ4_FAST_DEC_LOOP + safe_literal_copy: +#endif + /* copy literals */ + cpy = op+length; + + LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH); + if ((cpy>oend-MFLIMIT) || (ip+length>iend-(2+1+LASTLITERALS))) { + /* We've either hit the input parsing restriction or the output parsing restriction. + * In the normal scenario, decoding a full block, it must be the last sequence, + * otherwise it's an error (invalid input or dimensions). + * In partialDecoding scenario, it's necessary to ensure there is no buffer overflow. + */ + if (partialDecoding) { + /* Since we are partial decoding we may be in this block because of the output parsing + * restriction, which is not valid since the output buffer is allowed to be undersized. + */ + DEBUGLOG(7, "partialDecoding: copying literals, close to input or output end") + DEBUGLOG(7, "partialDecoding: literal length = %u", (unsigned)length); + DEBUGLOG(7, "partialDecoding: remaining space in dstBuffer : %i", (int)(oend - op)); + DEBUGLOG(7, "partialDecoding: remaining space in srcBuffer : %i", (int)(iend - ip)); + /* Finishing in the middle of a literals segment, + * due to lack of input. + */ + if (ip+length > iend) { + length = (size_t)(iend-ip); + cpy = op + length; + } + /* Finishing in the middle of a literals segment, + * due to lack of output space. + */ + if (cpy > oend) { + cpy = oend; + assert(op<=oend); + length = (size_t)(oend-op); + } + } else { + /* We must be on the last sequence (or invalid) because of the parsing limitations + * so check that we exactly consume the input and don't overrun the output buffer. + */ + if ((ip+length != iend) || (cpy > oend)) { + DEBUGLOG(5, "should have been last run of literals") + DEBUGLOG(5, "ip(%p) + length(%i) = %p != iend (%p)", ip, (int)length, ip+length, iend); + DEBUGLOG(5, "or cpy(%p) > (oend-MFLIMIT)(%p)", cpy, oend-MFLIMIT); + DEBUGLOG(5, "after writing %u bytes / %i bytes available", (unsigned)(op-(BYTE*)dst), outputSize); + goto _output_error; + } + } + LZ4_memmove(op, ip, length); /* supports overlapping memory regions, for in-place decompression scenarios */ + ip += length; + op += length; + /* Necessarily EOF when !partialDecoding. + * When partialDecoding, it is EOF if we've either + * filled the output buffer or + * can't proceed with reading an offset for following match. + */ + if (!partialDecoding || (cpy == oend) || (ip >= (iend-2))) { + break; + } + } else { + LZ4_wildCopy8(op, ip, cpy); /* can overwrite up to 8 bytes beyond cpy */ + ip += length; op = cpy; + } + + /* get offset */ + offset = LZ4_readLE16(ip); ip+=2; + match = op - offset; + + /* get matchlength */ + length = token & ML_MASK; + DEBUGLOG(7, "blockPos%6u: matchLength token = %u", (unsigned)(op-(BYTE*)dst), (unsigned)length); + + _copy_match: + if (length == ML_MASK) { + size_t const addl = read_variable_length(&ip, iend - LASTLITERALS + 1, 0); + if (addl == rvl_error) { goto _output_error; } + length += addl; + if (unlikely((uptrval)(op)+length<(uptrval)op)) goto _output_error; /* overflow detection */ + } + length += MINMATCH; + +#if LZ4_FAST_DEC_LOOP + safe_match_copy: +#endif + if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) goto _output_error; /* Error : offset outside buffers */ + /* match starting within external dictionary */ + if ((dict==usingExtDict) && (match < lowPrefix)) { + assert(dictEnd != NULL); + if (unlikely(op+length > oend-LASTLITERALS)) { + if (partialDecoding) length = MIN(length, (size_t)(oend-op)); + else goto _output_error; /* doesn't respect parsing restriction */ + } + + if (length <= (size_t)(lowPrefix-match)) { + /* match fits entirely within external dictionary : just copy */ + LZ4_memmove(op, dictEnd - (lowPrefix-match), length); + op += length; + } else { + /* match stretches into both external dictionary and current block */ + size_t const copySize = (size_t)(lowPrefix - match); + size_t const restSize = length - copySize; + LZ4_memcpy(op, dictEnd - copySize, copySize); + op += copySize; + if (restSize > (size_t)(op - lowPrefix)) { /* overlap copy */ + BYTE* const endOfMatch = op + restSize; + const BYTE* copyFrom = lowPrefix; + while (op < endOfMatch) *op++ = *copyFrom++; + } else { + LZ4_memcpy(op, lowPrefix, restSize); + op += restSize; + } } + continue; + } + assert(match >= lowPrefix); + + /* copy match within block */ + cpy = op + length; + + /* partialDecoding : may end anywhere within the block */ + assert(op<=oend); + if (partialDecoding && (cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { + size_t const mlen = MIN(length, (size_t)(oend-op)); + const BYTE* const matchEnd = match + mlen; + BYTE* const copyEnd = op + mlen; + if (matchEnd > op) { /* overlap copy */ + while (op < copyEnd) { *op++ = *match++; } + } else { + LZ4_memcpy(op, match, mlen); + } + op = copyEnd; + if (op == oend) { break; } + continue; + } + + if (unlikely(offset<8)) { + LZ4_write32(op, 0); /* silence msan warning when offset==0 */ + op[0] = match[0]; + op[1] = match[1]; + op[2] = match[2]; + op[3] = match[3]; + match += inc32table[offset]; + LZ4_memcpy(op+4, match, 4); + match -= dec64table[offset]; + } else { + LZ4_memcpy(op, match, 8); + match += 8; + } + op += 8; + + if (unlikely(cpy > oend-MATCH_SAFEGUARD_DISTANCE)) { + BYTE* const oCopyLimit = oend - (WILDCOPYLENGTH-1); + if (cpy > oend-LASTLITERALS) { goto _output_error; } /* Error : last LASTLITERALS bytes must be literals (uncompressed) */ + if (op < oCopyLimit) { + LZ4_wildCopy8(op, match, oCopyLimit); + match += oCopyLimit - op; + op = oCopyLimit; + } + while (op < cpy) { *op++ = *match++; } + } else { + LZ4_memcpy(op, match, 8); + if (length > 16) { LZ4_wildCopy8(op+8, match+8, cpy); } + } + op = cpy; /* wildcopy correction */ + } + + /* end of decoding */ + DEBUGLOG(5, "decoded %i bytes", (int) (((char*)op)-dst)); + return (int) (((char*)op)-dst); /* Nb of output bytes decoded */ + + /* Overflow error detected */ + _output_error: + return (int) (-(((const char*)ip)-src))-1; + } +} + + +/*===== Instantiate the API decoding functions. =====*/ + +LZ4_FORCE_O2 +int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, + decode_full_block, noDict, + (BYTE*)dest, NULL, 0); +} + +LZ4_FORCE_O2 +int LZ4_decompress_safe_partial(const char* src, char* dst, int compressedSize, int targetOutputSize, int dstCapacity) +{ + dstCapacity = MIN(targetOutputSize, dstCapacity); + return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity, + partial_decode, + noDict, (BYTE*)dst, NULL, 0); +} + +LZ4_FORCE_O2 +int LZ4_decompress_fast(const char* source, char* dest, int originalSize) +{ + DEBUGLOG(5, "LZ4_decompress_fast"); + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + 0, NULL, 0); +} + +/*===== Instantiate a few more decoding cases, used more than once. =====*/ + +LZ4_FORCE_O2 /* Exported, an obsolete API function. */ +int LZ4_decompress_safe_withPrefix64k(const char* source, char* dest, int compressedSize, int maxOutputSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + decode_full_block, withPrefix64k, + (BYTE*)dest - 64 KB, NULL, 0); +} + +LZ4_FORCE_O2 +static int LZ4_decompress_safe_partial_withPrefix64k(const char* source, char* dest, int compressedSize, int targetOutputSize, int dstCapacity) +{ + dstCapacity = MIN(targetOutputSize, dstCapacity); + return LZ4_decompress_generic(source, dest, compressedSize, dstCapacity, + partial_decode, withPrefix64k, + (BYTE*)dest - 64 KB, NULL, 0); +} + +/* Another obsolete API function, paired with the previous one. */ +int LZ4_decompress_fast_withPrefix64k(const char* source, char* dest, int originalSize) +{ + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + 64 KB, NULL, 0); +} + +LZ4_FORCE_O2 +static int LZ4_decompress_safe_withSmallPrefix(const char* source, char* dest, int compressedSize, int maxOutputSize, + size_t prefixSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + decode_full_block, noDict, + (BYTE*)dest-prefixSize, NULL, 0); +} + +LZ4_FORCE_O2 +static int LZ4_decompress_safe_partial_withSmallPrefix(const char* source, char* dest, int compressedSize, int targetOutputSize, int dstCapacity, + size_t prefixSize) +{ + dstCapacity = MIN(targetOutputSize, dstCapacity); + return LZ4_decompress_generic(source, dest, compressedSize, dstCapacity, + partial_decode, noDict, + (BYTE*)dest-prefixSize, NULL, 0); +} + +LZ4_FORCE_O2 +int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, + int compressedSize, int maxOutputSize, + const void* dictStart, size_t dictSize) +{ + DEBUGLOG(5, "LZ4_decompress_safe_forceExtDict"); + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + decode_full_block, usingExtDict, + (BYTE*)dest, (const BYTE*)dictStart, dictSize); +} + +LZ4_FORCE_O2 +int LZ4_decompress_safe_partial_forceExtDict(const char* source, char* dest, + int compressedSize, int targetOutputSize, int dstCapacity, + const void* dictStart, size_t dictSize) +{ + dstCapacity = MIN(targetOutputSize, dstCapacity); + return LZ4_decompress_generic(source, dest, compressedSize, dstCapacity, + partial_decode, usingExtDict, + (BYTE*)dest, (const BYTE*)dictStart, dictSize); +} + +LZ4_FORCE_O2 +static int LZ4_decompress_fast_extDict(const char* source, char* dest, int originalSize, + const void* dictStart, size_t dictSize) +{ + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + 0, (const BYTE*)dictStart, dictSize); +} + +/* The "double dictionary" mode, for use with e.g. ring buffers: the first part + * of the dictionary is passed as prefix, and the second via dictStart + dictSize. + * These routines are used only once, in LZ4_decompress_*_continue(). + */ +LZ4_FORCE_INLINE +int LZ4_decompress_safe_doubleDict(const char* source, char* dest, int compressedSize, int maxOutputSize, + size_t prefixSize, const void* dictStart, size_t dictSize) +{ + return LZ4_decompress_generic(source, dest, compressedSize, maxOutputSize, + decode_full_block, usingExtDict, + (BYTE*)dest-prefixSize, (const BYTE*)dictStart, dictSize); +} + +/*===== streaming decompression functions =====*/ + +#if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) +LZ4_streamDecode_t* LZ4_createStreamDecode(void) +{ + LZ4_STATIC_ASSERT(sizeof(LZ4_streamDecode_t) >= sizeof(LZ4_streamDecode_t_internal)); + return (LZ4_streamDecode_t*) ALLOC_AND_ZERO(sizeof(LZ4_streamDecode_t)); +} + +int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream) +{ + if (LZ4_stream == NULL) { return 0; } /* support free on NULL */ + FREEMEM(LZ4_stream); + return 0; +} +#endif + +/*! LZ4_setStreamDecode() : + * Use this function to instruct where to find the dictionary. + * This function is not necessary if previous data is still available where it was decoded. + * Loading a size of 0 is allowed (same effect as no dictionary). + * @return : 1 if OK, 0 if error + */ +int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize) +{ + LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse; + lz4sd->prefixSize = (size_t)dictSize; + if (dictSize) { + assert(dictionary != NULL); + lz4sd->prefixEnd = (const BYTE*) dictionary + dictSize; + } else { + lz4sd->prefixEnd = (const BYTE*) dictionary; + } + lz4sd->externalDict = NULL; + lz4sd->extDictSize = 0; + return 1; +} + +/*! LZ4_decoderRingBufferSize() : + * when setting a ring buffer for streaming decompression (optional scenario), + * provides the minimum size of this ring buffer + * to be compatible with any source respecting maxBlockSize condition. + * Note : in a ring buffer scenario, + * blocks are presumed decompressed next to each other. + * When not enough space remains for next block (remainingSize < maxBlockSize), + * decoding resumes from beginning of ring buffer. + * @return : minimum ring buffer size, + * or 0 if there is an error (invalid maxBlockSize). + */ +int LZ4_decoderRingBufferSize(int maxBlockSize) +{ + if (maxBlockSize < 0) return 0; + if (maxBlockSize > LZ4_MAX_INPUT_SIZE) return 0; + if (maxBlockSize < 16) maxBlockSize = 16; + return LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize); +} + +/* +*_continue() : + These decoding functions allow decompression of multiple blocks in "streaming" mode. + Previously decoded blocks must still be available at the memory position where they were decoded. + If it's not possible, save the relevant part of decoded data into a safe buffer, + and indicate where it stands using LZ4_setStreamDecode() +*/ +LZ4_FORCE_O2 +int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int compressedSize, int maxOutputSize) +{ + LZ4_streamDecode_t_internal* lz4sd = &LZ4_streamDecode->internal_donotuse; + int result; + + if (lz4sd->prefixSize == 0) { + /* The first call, no dictionary yet. */ + assert(lz4sd->extDictSize == 0); + result = LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize); + if (result <= 0) return result; + lz4sd->prefixSize = (size_t)result; + lz4sd->prefixEnd = (BYTE*)dest + result; + } else if (lz4sd->prefixEnd == (BYTE*)dest) { + /* They're rolling the current segment. */ + if (lz4sd->prefixSize >= 64 KB - 1) + result = LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize); + else if (lz4sd->extDictSize == 0) + result = LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, + lz4sd->prefixSize); + else + result = LZ4_decompress_safe_doubleDict(source, dest, compressedSize, maxOutputSize, + lz4sd->prefixSize, lz4sd->externalDict, lz4sd->extDictSize); + if (result <= 0) return result; + lz4sd->prefixSize += (size_t)result; + lz4sd->prefixEnd += result; + } else { + /* The buffer wraps around, or they're switching to another buffer. */ + lz4sd->extDictSize = lz4sd->prefixSize; + lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize; + result = LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize, + lz4sd->externalDict, lz4sd->extDictSize); + if (result <= 0) return result; + lz4sd->prefixSize = (size_t)result; + lz4sd->prefixEnd = (BYTE*)dest + result; + } + + return result; +} + +LZ4_FORCE_O2 int +LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, + const char* source, char* dest, int originalSize) +{ + LZ4_streamDecode_t_internal* const lz4sd = + (assert(LZ4_streamDecode!=NULL), &LZ4_streamDecode->internal_donotuse); + int result; + + DEBUGLOG(5, "LZ4_decompress_fast_continue (toDecodeSize=%i)", originalSize); + assert(originalSize >= 0); + + if (lz4sd->prefixSize == 0) { + DEBUGLOG(5, "first invocation : no prefix nor extDict"); + assert(lz4sd->extDictSize == 0); + result = LZ4_decompress_fast(source, dest, originalSize); + if (result <= 0) return result; + lz4sd->prefixSize = (size_t)originalSize; + lz4sd->prefixEnd = (BYTE*)dest + originalSize; + } else if (lz4sd->prefixEnd == (BYTE*)dest) { + DEBUGLOG(5, "continue using existing prefix"); + result = LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + lz4sd->prefixSize, + lz4sd->externalDict, lz4sd->extDictSize); + if (result <= 0) return result; + lz4sd->prefixSize += (size_t)originalSize; + lz4sd->prefixEnd += originalSize; + } else { + DEBUGLOG(5, "prefix becomes extDict"); + lz4sd->extDictSize = lz4sd->prefixSize; + lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize; + result = LZ4_decompress_fast_extDict(source, dest, originalSize, + lz4sd->externalDict, lz4sd->extDictSize); + if (result <= 0) return result; + lz4sd->prefixSize = (size_t)originalSize; + lz4sd->prefixEnd = (BYTE*)dest + originalSize; + } + + return result; +} + + +/* +Advanced decoding functions : +*_usingDict() : + These decoding functions work the same as "_continue" ones, + the dictionary must be explicitly provided within parameters +*/ + +int LZ4_decompress_safe_usingDict(const char* source, char* dest, int compressedSize, int maxOutputSize, const char* dictStart, int dictSize) +{ + if (dictSize==0) + return LZ4_decompress_safe(source, dest, compressedSize, maxOutputSize); + if (dictStart+dictSize == dest) { + if (dictSize >= 64 KB - 1) { + return LZ4_decompress_safe_withPrefix64k(source, dest, compressedSize, maxOutputSize); + } + assert(dictSize >= 0); + return LZ4_decompress_safe_withSmallPrefix(source, dest, compressedSize, maxOutputSize, (size_t)dictSize); + } + assert(dictSize >= 0); + return LZ4_decompress_safe_forceExtDict(source, dest, compressedSize, maxOutputSize, dictStart, (size_t)dictSize); +} + +int LZ4_decompress_safe_partial_usingDict(const char* source, char* dest, int compressedSize, int targetOutputSize, int dstCapacity, const char* dictStart, int dictSize) +{ + if (dictSize==0) + return LZ4_decompress_safe_partial(source, dest, compressedSize, targetOutputSize, dstCapacity); + if (dictStart+dictSize == dest) { + if (dictSize >= 64 KB - 1) { + return LZ4_decompress_safe_partial_withPrefix64k(source, dest, compressedSize, targetOutputSize, dstCapacity); + } + assert(dictSize >= 0); + return LZ4_decompress_safe_partial_withSmallPrefix(source, dest, compressedSize, targetOutputSize, dstCapacity, (size_t)dictSize); + } + assert(dictSize >= 0); + return LZ4_decompress_safe_partial_forceExtDict(source, dest, compressedSize, targetOutputSize, dstCapacity, dictStart, (size_t)dictSize); +} + +int LZ4_decompress_fast_usingDict(const char* source, char* dest, int originalSize, const char* dictStart, int dictSize) +{ + if (dictSize==0 || dictStart+dictSize == dest) + return LZ4_decompress_unsafe_generic( + (const BYTE*)source, (BYTE*)dest, originalSize, + (size_t)dictSize, NULL, 0); + assert(dictSize >= 0); + return LZ4_decompress_fast_extDict(source, dest, originalSize, dictStart, (size_t)dictSize); +} + + +/*=************************************************* +* Obsolete Functions +***************************************************/ +/* obsolete compression functions */ +int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize) +{ + return LZ4_compress_default(source, dest, inputSize, maxOutputSize); +} +int LZ4_compress(const char* src, char* dest, int srcSize) +{ + return LZ4_compress_default(src, dest, srcSize, LZ4_compressBound(srcSize)); +} +int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize) +{ + return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1); +} +int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize) +{ + return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1); +} +int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int dstCapacity) +{ + return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, dstCapacity, 1); +} +int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize) +{ + return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1); +} + +/* +These decompression functions are deprecated and should no longer be used. +They are only provided here for compatibility with older user programs. +- LZ4_uncompress is totally equivalent to LZ4_decompress_fast +- LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe +*/ +int LZ4_uncompress (const char* source, char* dest, int outputSize) +{ + return LZ4_decompress_fast(source, dest, outputSize); +} +int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize) +{ + return LZ4_decompress_safe(source, dest, isize, maxOutputSize); +} + +/* Obsolete Streaming functions */ + +int LZ4_sizeofStreamState(void) { return sizeof(LZ4_stream_t); } + +int LZ4_resetStreamState(void* state, char* inputBuffer) +{ + (void)inputBuffer; + LZ4_resetStream((LZ4_stream_t*)state); + return 0; +} + +#if !defined(LZ4_STATIC_LINKING_ONLY_DISABLE_MEMORY_ALLOCATION) +void* LZ4_create (char* inputBuffer) +{ + (void)inputBuffer; + return LZ4_createStream(); +} +#endif + +char* LZ4_slideInputBuffer (void* state) +{ + /* avoid const char * -> char * conversion warning */ + return (char *)(uptrval)((LZ4_stream_t*)state)->internal_donotuse.dictionary; +} + +#endif /* LZ4_COMMONDEFS_ONLY */
lib/lz4/upstream/lz4.h new file +884 -0
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lib/lz4/upstream/lz4hc.c new file +2192 -0
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lib/lz4/upstream/lz4hc.h new file +414 -0
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Signature · 1 line
2.34.1
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PATCH v2 5/15 lib/lz4: backport upstream's -Wmissing-prototypes fix
In reply to Michal Wilczynskiv1.10.0 defines LZ4_loadDict_internal() in lz4.c and LZ4HC_searchExtDict() in lz4hc.c with external linkage and no prototype, which the kernel's -Wmissing-prototypes rejects. The first would also prevent linking once lz4_compress.c and lz4_decompress.c both include lz4.c, later in this series, since each would define it.
Neither can be forward declared static in the lz4_deps.h a later patch adds, as the other bare helpers are, because their signatures use types declared inside the .c files.
Take the two hunks of upstream commit 5ef1f16929b5
("fix -Wmissing-prototypes warnings") that apply to the files we vendor. This goes away at the next re-sync.
--- lib/lz4/upstream/lz4.c | 2 +- lib/lz4/upstream/lz4hc.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
lib/lz4/upstream/lz4.c +1 -1
@@ -1584,7 +1584,7 @@ int LZ4_freeStream (LZ4_stream_t* LZ4_stream)typedef enum { _ld_fast, _ld_slow }LoadDict_mode_e ;#define HASH_UNIT sizeof(reg_t) -int LZ4_loadDict_internal (LZ4_stream_t * LZ4_dict, +static int LZ4_loadDict_internal (LZ4_stream_t * LZ4_dict,const char * dictionary,int dictSize,LoadDict_mode_e _ld) {
lib/lz4/upstream/lz4hc.c +1 -1
@@ -360,7 +360,7 @@ typedef struct {int back;/* negative value */ } LZ4HC_match_t; -LZ4HC_match_t LZ4HC_searchExtDict (const BYTE * ip,U32 ipIndex, +static LZ4HC_match_t LZ4HC_searchExtDict (const BYTE * ip,U32 ipIndex,const BYTE *const iLowLimit,const BYTE *const iHighLimit,const LZ4HC_CCtx_internal * dictCtx,U32 gDictEndIndex,int currentBestML,int nbAttempts)
Signature · 1 line
2.34.1
PATCH v2 6/15 lib/lz4: backport upstream's aarch64 fast decode loop enablement
In reply to Michal Wilczynskiv1.10.0 leaves LZ4_FAST_DEC_LOOP off for aarch64 built with clang, after a slowdown reported on some Android phones in 2019 (upstream PR #707). An arm64 kernel built with clang therefore decodes with the slower loop.
Upstream has since enabled it for all aarch64, in three unreleased commits:
commit 0aa33884faf5 ("[LZ4] Limit disabling LZ4_FAST_DEC_LOOP to aarch64+clang+android") commit 51f8af506b4a ("Fix missing endif")
commit ed86bc1ed802 ("AArch64: Enable LZ4_FAST_DEC_LOOP for Android")
Arm measured +3.5% to +15.6% on Cortex-A510 to X4 with clang. Take the lz4.c hunks of all three. This goes away at the next re-sync.
--- lib/lz4/upstream/lz4.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-)
lib/lz4/upstream/lz4.c +1 -6
@@ -478,12 +478,7 @@ static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};#ifndef LZ4_FAST_DEC_LOOP # if defined __i386__ || defined _M_IX86 || defined __x86_64__ || defined _M_X64# define LZ4_FAST_DEC_LOOP 1 -# elif defined(__aarch64__) && defined(__APPLE__) -# define LZ4_FAST_DEC_LOOP 1 -# elif defined(__aarch64__) && !defined(__clang__) -/* On non-Apple aarch64, we disable this optimization for clang because -* on certain mobile chipsets, performance is reduced with clang. For -* more information refer to https://github.com/lz4/lz4/pull/707 */ +# elif defined(__aarch64__)# define LZ4_FAST_DEC_LOOP 1# else # define LZ4_FAST_DEC_LOOP 0
Signature · 1 line
2.34.1
PATCH v2 7/15 lib/lz4: backport upstream's match length limit fix
In reply to Michal Wilczynskiv1.10.0 lets a match length's extension bytes run to four bytes before the end of the block, which leaves room for only a token and three literals where the format requires five. The fork rejected such blocks, v1.10.0 decodes them: 1f 41 01 00 ff 00 30 7a 7a 7a decodes to 278 bytes instead of failing.
Upstream fixed this in 587ed9557708 ("add comments explaining read_variable_length() ilimit bounds, fix match length limit"), on top of a read_variable_length() rework v1.10.0 does not have. Both versions accept the same final ip for a given limit, so change the limit at the two match length call sites to iend - (1 + LASTLITERALS), as upstream does. This is one byte stricter than the fork; no compressor produces the blocks it newly rejects.
This goes away at the next re-sync.
--- lib/lz4/upstream/lz4.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
lib/lz4/upstream/lz4.c +2 -2
@@ -2120,7 +2120,7 @@ LZ4_decompress_generic(DEBUGLOG (7 ," match length token = %u (len==%u)" , (unsigned )length, (unsigned )length+MINMATCH );if (length ==ML_MASK ) { -size_t const addl =read_variable_length (&ip, iend -LASTLITERALS +1 ,0 ); +size_t const addl =read_variable_length (&ip, iend - (1 +LASTLITERALS ),0 );if (addl == rvl_error) {DEBUGLOG (5 ,"error reading long match length" ); goto _output_error;
@@ -2338,7 +2338,7 @@ LZ4_decompress_generic( _copy_match:if (length ==ML_MASK ) { -size_t const addl =read_variable_length (&ip, iend -LASTLITERALS +1 ,0 ); +size_t const addl =read_variable_length (&ip, iend - (1 +LASTLITERALS ),0 );if (addl == rvl_error) { goto _output_error; } length += addl;if (unlikely ((uptrval)(op)+length<(uptrval )op)) goto _output_error;/* overflow detection */
Signature · 1 line
2.34.1
PATCH v2 8/15 lib/lz4: add the build environment for the vendored sources
In reply to Michal Wilczynskilz4_deps.h makes the vendored upstream sources build in the kernel. It gives every upstream entry point internal linkage, so an object carries only the codec it forwards, selects heap mode with failing allocators so LZ4HC's ~64K optimal-parser buffer stays off the stack, and renames the entry points the kernel re-exports so the kernel's own definitions can use the real names. LZ4LIB_VISIBILITY carries __maybe_unused for the functions an object does not use.
freestanding/ forwards the four ISO C headers upstream includes to their <linux/> equivalents. lz4_kernel_api.h undoes the renaming; it carries its own copy of the exported prototypes until a later patch can include <linux/lz4.h> instead.
Two settings upstream leaves to the build:
- Unaligned access goes through memcpy() where the architecture has efficient unaligned access, and through packed structs, as get_unaligned() does, elsewhere. Left alone, upstream uses plain misaligned loads on ARMv6.
- On ppc64le, lz4.c marks functions __attribute__((optimize("O2"))) for GCC, which drops command line options such as -fno-strict-aliasing for them; see commit 080b6f407635 ("bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE"). lz4_deps.h defines optimize() to nothing for upstream's sources.
Nothing includes either header yet.
--- lib/lz4/freestanding/limits.h | 14 +++++ lib/lz4/freestanding/stddef.h | 15 ++++++ lib/lz4/freestanding/stdint.h | 14 +++++ lib/lz4/freestanding/string.h | 14 +++++ lib/lz4/lz4_deps.h | 118 ++++++++++++++++++++++++++++++++++++++++++ lib/lz4/lz4_kernel_api.h | 90 ++++++++++++++++++++++++++++++++ 6 files changed, 265 insertions(+)
lib/lz4/freestanding/limits.h new file +14 -0
@@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* +* Copyright (c) 2026 Samsung Electronics Co., Ltd. +* Author: Michal Wilczynski <[email protected]> +* +* Freestanding <limits.h> for the vendored upstream LZ4 sources; lz4.c needs +* UINT_MAX and lz4hc.c needs INT_MAX. +*/ +#ifndef __LZ4_FREESTANDING_LIMITS_H__ +#define __LZ4_FREESTANDING_LIMITS_H__ + +#include <linux/limits.h> + +#endif
lib/lz4/freestanding/stddef.h new file +15 -0
@@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* +* Copyright (c) 2026 Samsung Electronics Co., Ltd. +* Author: Michal Wilczynski <[email protected]> +* +* Freestanding <stddef.h> for the vendored upstream LZ4 sources; -nostdinc +* drops the compiler's copy, and lz4.h needs size_t and NULL. +*/ +#ifndef __LZ4_FREESTANDING_STDDEF_H__ +#define __LZ4_FREESTANDING_STDDEF_H__ + +#include <linux/stddef.h> /* NULL, offsetof */ +#include <linux/types.h> /* size_t, ptrdiff_t */ + +#endif
lib/lz4/freestanding/stdint.h new file +14 -0
@@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* +* Copyright (c) 2026 Samsung Electronics Co., Ltd. +* Author: Michal Wilczynski <[email protected]> +* +* Freestanding <stdint.h> for the vendored upstream LZ4 sources; forwards to +* <linux/types.h>. +*/ +#ifndef __LZ4_FREESTANDING_STDINT_H__ +#define __LZ4_FREESTANDING_STDINT_H__ + +#include <linux/types.h> + +#endif
lib/lz4/freestanding/string.h new file +14 -0
@@ -0,0 +1,14 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* +* Copyright (c) 2026 Samsung Electronics Co., Ltd. +* Author: Michal Wilczynski <[email protected]> +* +* Freestanding <string.h> for the vendored upstream LZ4 sources; lz4.c +* includes it for memcpy()/memset(), which must resolve under -nostdinc. +*/ +#ifndef __LZ4_FREESTANDING_STRING_H__ +#define __LZ4_FREESTANDING_STRING_H__ + +#include <linux/string.h> + +#endif
lib/lz4/lz4_deps.h new file +118 -0
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lib/lz4/lz4_kernel_api.h new file +90 -0
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Signature · 1 line
2.34.1
PATCH v2 9/15 arch: boot: put the LZ4 freestanding headers on the decompressor path
In reply to Michal Wilczynskilib/decompress_unlz4.c pulls lib/lz4/lz4_decompress.c into the pre-boot decompressor on these five arches. A later patch makes that file include the vendored LZ4 sources, which include ISO C headers that -nostdinc does not provide, so put lib/lz4/freestanding on the include path first.
Only the one object that includes decompress_unlz4.c gets it, so the rest of each boot directory keeps -nostdinc's view.
--- arch/arm/boot/compressed/Makefile | 3 +++ arch/mips/boot/compressed/Makefile | 4 ++++ arch/parisc/boot/compressed/Makefile | 3 +++ arch/s390/boot/Makefile | 3 +++ arch/x86/boot/compressed/Makefile | 3 +++ 5 files changed, 16 insertions(+)
arch/arm/boot/compressed/Makefile +3 -0
@@ -92,6 +92,9 @@ targets := vmlinux vmlinux.lds piggy_data piggy.o \ head.o $(OBJS) KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING +# decompress.c includes decompress_unlz4.c, which builds the vendored LZ4 +# sources; they include a few ISO C headers -nostdinc drops. +CFLAGS_decompress.o += -I$(srctree)/lib/lz4/freestanding ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin \ -I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
arch/mips/boot/compressed/Makefile +4 -0
@@ -30,6 +30,10 @@ endif KBUILD_CFLAGS := $(KBUILD_CFLAGS) -D__KERNEL__ -D__DISABLE_EXPORTS \ -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) -D"VMLINUX_LOAD_ADDRESS_ULL=$(VMLINUX_LOAD_ADDRESS)ull" +# decompress.c includes decompress_unlz4.c, which builds the vendored LZ4 +# sources; they include a few ISO C headers -nostdinc drops. +CFLAGS_decompress.o += -I$(srctree)/lib/lz4/freestanding + KBUILD_AFLAGS := $(KBUILD_AFLAGS) -D__ASSEMBLY__ \ -DBOOT_HEAP_SIZE=$(BOOT_HEAP_SIZE) \ -DKERNEL_ENTRY=$(VMLINUX_ENTRY_ADDRESS)
arch/parisc/boot/compressed/Makefile +3 -0
@@ -12,6 +12,9 @@ targets += $(OBJECTS) sizes.h KBUILD_CFLAGS := -D__KERNEL__ -O2 -DBOOTLOADER KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING +# misc.c includes decompress_unlz4.c, which builds the vendored LZ4 +# sources; they include a few ISO C headers -nostdinc drops. +CFLAGS_misc.o += -I$(srctree)/lib/lz4/freestanding KBUILD_CFLAGS += -fno-strict-aliasing KBUILD_CFLAGS += $(cflags-y) -fno-delete-null-pointer-checks -fno-builtin-printf KBUILD_CFLAGS += -fno-PIE -mno-space-regs -mdisable-fpregs -Os
arch/s390/boot/Makefile +3 -0
@@ -21,6 +21,9 @@ KBUILD_AFLAGS := $(filter-out $(CC_FLAGS_MARCH),$(KBUILD_AFLAGS_DECOMPRESSOR)) KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_MARCH),$(KBUILD_CFLAGS_DECOMPRESSOR)) KBUILD_AFLAGS += $(CC_FLAGS_MARCH_MINIMUM) -D__DISABLE_EXPORTS KBUILD_CFLAGS += $(CC_FLAGS_MARCH_MINIMUM) -D__DISABLE_EXPORTS +# decompressor.c includes decompress_unlz4.c, which builds the vendored LZ4 +# sources; they include a few ISO C headers -nostdinc drops. +CFLAGS_decompressor.o += -I$(srctree)/lib/lz4/freestanding KBUILD_CFLAGS += $(call cc-option, -Wno-default-const-init-unsafe) CFLAGS_sclp_early_core.o += -I$(srctree)/drivers/s390/char
arch/x86/boot/compressed/Makefile +3 -0
@@ -30,6 +30,9 @@ KBUILD_CFLAGS += -fno-strict-aliasing -fPIE KBUILD_CFLAGS += -fno-jump-tables KBUILD_CFLAGS += -Wundef KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING +# misc.c includes decompress_unlz4.c, which builds the vendored LZ4 +# sources; they include a few ISO C headers -nostdinc drops. +CFLAGS_misc.o += -I$(srctree)/lib/lz4/freestanding cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone KBUILD_CFLAGS += $(cflags-y)
Signature · 1 line
2.34.1
PATCH v2 10/15 lib/lz4: switch the compressor to the vendored sources
In reply to Michal WilczynskiReplace the forked compressor with thin entry points over the vendored lz4.c. LZ4_compress_default(), LZ4_compress_fast() and LZ4_compress_destSize() keep the trailing wrkmem argument and forward to upstream's *_extState() functions; the rest are plain forwarders.
Upstream's LZ4_initStream() returns NULL for a misaligned workspace, which LZ4_compress_fast_extState() dereferences and LZ4_compress_destSize_extState() ignores. Check the alignment in the entry points, warn once and fail the call. In-tree callers allocate with kmalloc() or vmalloc() and are not affected.
Compressed output differs from the fork's on a small fraction of inputs by a byte or two; both decode each other's output. Compressing 4K blocks, upstream is 2-4% faster on kernel source and binaries and up to 9% slower on datagen.
LZ4_stream_t becomes an incomplete type, as upstream declares it, so <linux/lz4.h> and upstream's lz4.h can share a translation unit. The macros that laid out the forked structure go, and LZ4_MEM_COMPRESS keeps its value, 16416. zram, the only caller using sizeof(LZ4_stream_t), now allocates LZ4_MEM_COMPRESS bytes.
--- drivers/block/zram/backend_lz4.c | 6 +- include/linux/lz4.h | 47 +- lib/lz4/Makefile | 12 +- lib/lz4/lz4_compress.c | 946 +++------------------------------------ 4 files changed, 80 insertions(+), 931 deletions(-)
drivers/block/zram/backend_lz4.c +3 -3
@@ -42,7 +42,7 @@ static int lz4_setup_params(struct zcomp_params *params)if (!params->dict || !params->dict_sz)return 0 ; - dict_stream =kzalloc_obj (*dict_stream); + dict_stream =kzalloc (LZ4_MEM_COMPRESS ,GFP_KERNEL );if (!dict_stream)return -ENOMEM ;
@@ -88,7 +88,7 @@ static int lz4_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->dstrm) goto error; - zctx->cstrm =kzalloc_obj (*zctx->cstrm); + zctx->cstrm =kzalloc (LZ4_MEM_COMPRESS ,GFP_KERNEL );if (!zctx->cstrm) goto error; }
@@ -112,7 +112,7 @@ static int lz4_compress(struct zcomp_params *params, struct zcomp_ctx *ctx, zctx->mem); }else {/* Cstrm needs to be reset */ -memcpy (zctx->cstrm, params->drv_data,sizeof (*zctx->cstrm)); +memcpy (zctx->cstrm, params->drv_data,LZ4_MEM_COMPRESS ); ret =LZ4_compress_fast_continue (zctx->cstrm, req->src, req->dst, req->src_len, req->dst_len, params->level);
include/linux/lz4.h +13 -34
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lib/lz4/Makefile +9 -3
@@ -1,6 +1,12 @@ # SPDX-License-Identifier: GPL-2.0-only ccflags-y += -O3 -obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o -obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o -obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o +# upstream/ holds the upstream LZ4 sources lz4_deps.h describes; replace them +# with a later release rather than patch them further. The three entry point +# files include them. freestanding/ supplies the ISO C headers upstream +# includes that -nostdinc does not provide. +ccflags-y += -I $(src)/freestanding + +obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o +obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o +obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o
lib/lz4/lz4_compress.c +55 -891
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Signature · 1 line
2.34.1
PATCH v2 11/15 lib/lz4: switch the HC compressor to the vendored sources
In reply to Michal WilczynskiReplace the forked LZ4HC with thin entry points over the vendored lz4hc.c.
Upstream routes levels 10 and up to its optimal parser, whose ~64K workspace the kernel cannot provide. Clamp those levels to 9 rather than reject them, so existing f2fs and zram settings keep working, and add LZ4HC_CLAMP_CLEVEL to <linux/lz4.h>. Document the clamp in f2fs.rst.
Levels 1 and 2 now use upstream's lz4mid: on kernel source they are 50-84% faster for 4-9% larger output. Levels 3 to 9 compress the same, but at 4K are up to 15% slower on poorly compressible data, including at level 9, zram's lz4hc default.
LZ4_compress_HC() and LZ4_resetStreamHC() check the state's alignment like the compressor's entry points.
LZ4_streamHC_t becomes incomplete and the macros that laid out the forked structure go. LZ4HC_MEM_COMPRESS grows from 262192 to upstream's 262200, static_asserted against LZ4_STREAMHC_MINSIZE. lz4hc.c pulls in lz4.c's decoder tables, unused here when the fast decode loop is off, so silence -Wunused-const-variable for this object.
This retires commit b08918fb3f27 ("lz4: do not export static symbol"):
the glue exports only the five LZ4HC entry points.
--- Documentation/filesystems/f2fs.rst | 2 + drivers/block/zram/backend_lz4hc.c | 2 +- include/linux/lz4.h | 54 +-- lib/lz4/Makefile | 4 + lib/lz4/lz4hc_compress.c | 792 ++++--------------------------------- 5 files changed, 91 insertions(+), 763 deletions(-)
Documentation/filesystems/f2fs.rst +2 -0
@@ -318,6 +318,8 @@ compress_algorithm=%s:%d Control compress algorithm and its compress level, now, zstd 1 - 22 ========= =========== + lz4 levels above 9 compress as level 9. + compress_log_size=%u Support configuring compress cluster size. The size will be 4KB * (1 << %u). The default and minimum sizes are 16KB. compress_extension=%s Support adding specified extension, so that f2fs can enable
drivers/block/zram/backend_lz4hc.c +1 -1
@@ -69,7 +69,7 @@ static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->dstrm) goto error; - zctx->cstrm =kzalloc_obj (*zctx->cstrm); + zctx->cstrm =kzalloc (LZ4HC_MEM_COMPRESS ,GFP_KERNEL );if (!zctx->cstrm) goto error;LZ4_resetStreamHC (zctx->cstrm, params->level);
include/linux/lz4.h +16 -38
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lib/lz4/Makefile +4 -0
@@ -10,3 +10,7 @@ ccflags-y += -I $(src)/freestanding obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o + +# lz4hc.c pulls in lz4.c's common definitions, which include two decoder +# tables nothing here uses when LZ4_FAST_DEC_LOOP is off. +CFLAGS_lz4hc_compress.o += $(call cc-disable-warning, unused-const-variable)
lib/lz4/lz4hc_compress.c +68 -724
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Signature · 1 line
2.34.1
PATCH v2 12/15 lib/lz4: widen LZ4_DECOMPRESS_INPLACE_MARGIN for the fast decode loop
In reply to Michal Wilczynskierofs decompresses a pcluster in place when the slack after the output is at least LZ4_DECOMPRESS_INPLACE_MARGIN(compressed size), upstream's (compressedSize >> 8) + 32.
That holds for the fork, which overshoots its output by at most 8 bytes. Upstream's LZ4_FAST_DEC_LOOP, which the next patch brings in for x86 and arm64, copies in 32-byte steps and can overwrite input it has not read yet: of 172410 valid streams laid out as erofs does at exactly that margin, 3660 fail to decode, none with the fork. The worst needs (compressedSize >> 8) + 33. Images mkfs.erofs built did not hit this, but nothing in the format rules it out.
Use (compressedSize >> 8) + (compressedSize >> 15) + 36, which takes a 4K pcluster's margin from 48 to 52 bytes. Upstream's lz4.h defines the macro too, so undefine it first.
--- include/linux/lz4.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)
include/linux/lz4.h +12 -1
@@ -521,7 +521,18 @@ int LZ4_decompress_safe_usingDict(const char *source, char *dest, int compressedSize, int maxDecompressedSize, const char *dictStart, int dictSize); -#define LZ4_DECOMPRESS_INPLACE_MARGIN (compressedSize) (((compressedSize) >> 8) + 32) +/* +* Slack needed after the decompressed data for LZ4_decompress_safe() to +* decode in place, with the compressed data at the end of the buffer. +* Upstream's (compressedSize >> 8) + 32 can be a few bytes short: its fast +* decode loop copies in 32-byte steps, which may overwrite input it has +* not read yet. The >> 15 term is extra headroom for large pclusters. +* Upstream's lz4.h, which lib/lz4's objects also see, defines the macro +* too. +*/ +#undef LZ4_DECOMPRESS_INPLACE_MARGIN +#define LZ4_DECOMPRESS_INPLACE_MARGIN (compressedSize) \ + (((compressedSize) >> 8) + ((compressedSize) >> 15) + 36)#ifndef LZ4_DISTANCE_MAX /* history window size; can be user-defined at compile time */ #define LZ4_DISTANCE_MAX 65535/* set to maximum value by default */
Signature · 1 line
2.34.1
PATCH v2 13/15 lib/lz4: switch the decompressor to the vendored sources
In reply to Michal WilczynskiReplace the forked decompressor with thin entry points over the vendored lz4.c; the API is signature-compatible, so every export is a plain forwarder. lz4defs.h has no users left and goes.
lib/decompress_unlz4.c includes this file before boot, together with <linux/lz4.h>, so LZ4_streamDecode_t becomes incomplete as upstream declares it, and LZ4_MEM_DECOMPRESS (32) replaces the LZ4_STREAMDECODESIZE macros. LZ4_COMPRESSBOUND is defined by both headers and gets a guard; the LZ4_compressBound() wrapper goes, as lib/decompress_unlz4.c now uses the macro.
LZ4_decompress_safe_partial() on a truncated block can now return the bytes decoded so far rather than an error, depending on where the cut falls; the kernel-doc says so.
This retires six local patches:
commit 8cb5d7482810 ("lib/lz4: make arrays static const, reduces object code size")
upstream 75fb878a9019 ("decompress_generic: Add fastpath for small offsets"), v1.9.0
commit b1a3e75e466d ("lz4: fix kernel decompression speed")
upstream fe2a1b3707d5 ("Call LZ4_memcpy() instead of memcpy()"), v1.9.3
commit 89b158635ad7 ("lib/lz4: explicitly support in-place decompression")
upstream 33cb8518ac38 ("decompress: changed final memcpy() into memmove()"), v1.9.2
commit 7fde9d6e839d ("lz4_decompress: declare LZ4_decompress_safe_withPrefix64k static")
LZ4LIB_VISIBILITY in lz4_deps.h, which makes every upstream entry point static
commit eafc0a02391b ("lz4: fix LZ4_decompress_safe_partial read out of bound")
upstream c5d6f8a8be39 ("fix #783"), v1.9.3
commit 2d8867f3e083 ("lib: make LZ4_decompress_safe_forceExtDict() static")
the static forward declaration in lz4_deps.h
--- drivers/block/zram/backend_lz4.c | 2 +- drivers/block/zram/backend_lz4hc.c | 2 +- include/linux/lz4.h | 60 ++-- lib/decompress_unlz4.c | 4 +- lib/lz4/lz4_decompress.c | 640 +++---------------------------------- lib/lz4/lz4defs.h | 247 -------------- 6 files changed, 71 insertions(+), 884 deletions(-)
drivers/block/zram/backend_lz4.c +1 -1
@@ -84,7 +84,7 @@ static int lz4_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->mem) goto error; }else { - zctx->dstrm =kzalloc_obj (*zctx->dstrm); + zctx->dstrm =kzalloc (LZ4_MEM_DECOMPRESS ,GFP_KERNEL );if (!zctx->dstrm) goto error;
drivers/block/zram/backend_lz4hc.c +1 -1
@@ -65,7 +65,7 @@ static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->mem) goto error; }else { - zctx->dstrm =kzalloc_obj (*zctx->dstrm); + zctx->dstrm =kzalloc (LZ4_MEM_DECOMPRESS ,GFP_KERNEL );if (!zctx->dstrm) goto error;
include/linux/lz4.h +22 -38
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lib/decompress_unlz4.c +2 -2
@@ -69,7 +69,7 @@ STATIC inline int INIT unlz4(u8 *input, long in_len,error ("NULL input pointer and missing fill function" ); goto exit_1; }else { - inp =large_malloc (LZ4_compressBound (uncomp_chunksize)); + inp =large_malloc (LZ4_COMPRESSBOUND (uncomp_chunksize));if (!inp) {error ("Could not allocate input buffer" ); goto exit_1;
@@ -140,7 +140,7 @@ STATIC inline int INIT unlz4(u8 *input, long in_len, inp +=4 ; size -=4 ; }else { -if (chunksize >LZ4_compressBound (uncomp_chunksize)) { +if (chunksize >LZ4_COMPRESSBOUND (uncomp_chunksize)) {error ("chunk length is longer than allocated" ); goto exit_2; }
lib/lz4/lz4_decompress.c +45 -595
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lib/lz4/lz4defs.h deleted +0 -247
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Signature · 1 line
2.34.1
PATCH v2 14/15 lib/lz4: replace lz4_kernel_api.h's prototypes with <linux/lz4.h>
In reply to Michal Wilczynskilz4_kernel_api.h carried its own copy of the twenty public prototypes because it could not include <linux/lz4.h>, which defined the stream types that upstream's headers also define.
The types are incomplete now, so it can. Two prototype lists for one ABI is a drift hazard: the entry points were built against one and their callers against the other, so no compiler ever saw both, and MODVERSIONS would not catch a mismatch either, since it hashes the exporter's view only. Now there is one list.
It also puts the public constants in scope of the entry points, so the size assertions can name them, and the HC level clamp can use LZ4HC_CLAMP_CLEVEL, static_asserted equal to upstream's LZ4HC_CLEVEL_OPT_MIN.
--- lib/lz4/lz4_compress.c | 2 +- lib/lz4/lz4_decompress.c | 2 +- lib/lz4/lz4_kernel_api.h | 64 +++--------------------------------------------- lib/lz4/lz4hc_compress.c | 8 +++--- 4 files changed, 11 insertions(+), 65 deletions(-)
lib/lz4/lz4_compress.c +1 -1
@@ -30,7 +30,7 @@/* Catch any divergence from upstream's layout at build time. */ static_assert (sizeof (LZ4_stream_t) ==LZ4_STREAM_MINSIZE ); -static_assert (LZ4_STREAM_MINSIZE ==16416 );/* LZ4_MEM_COMPRESS */ +static_assert (LZ4_STREAM_MINSIZE ==LZ4_MEM_COMPRESS );/* LZ4_initStream() returns NULL for a misaligned state, which * LZ4_compress_fast_extState() dereferences and
lib/lz4/lz4_decompress.c +1 -1
@@ -31,7 +31,7 @@#endif static_assert (sizeof (LZ4_streamDecode_t) ==LZ4_STREAMDECODE_MINSIZE ); -static_assert (LZ4_STREAMDECODE_MINSIZE ==32 );/* LZ4_MEM_DECOMPRESS */ +static_assert (LZ4_STREAMDECODE_MINSIZE ==LZ4_MEM_DECOMPRESS );int LZ4_decompress_safe (const char *source,char *dest,int compressedSize,int maxDecompressedSize)
lib/lz4/lz4_kernel_api.h +4 -60
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lib/lz4/lz4hc_compress.c +5 -3
@@ -39,7 +39,7 @@ static int LZ4_compressBound(int isize)/* Catch any divergence from upstream's layout at build time. */ static_assert (sizeof (LZ4_streamHC_t) ==LZ4_STREAMHC_MINSIZE ); -static_assert (LZ4_STREAMHC_MINSIZE ==262200 );/* LZ4HC_MEM_COMPRESS */ +static_assert (LZ4_STREAMHC_MINSIZE ==LZ4HC_MEM_COMPRESS );/* Levels >= LZ4HC_CLEVEL_OPT_MIN (10) reach the optimal parser, which needs * a ~64K opt[]: too big for a kernel stack, and in the heap mode lz4_deps.h
@@ -48,10 +48,12 @@ static_assert(LZ4_STREAMHC_MINSIZE == 262200); /* LZ4HC_MEM_COMPRESS */* working. Levels 3..9 keep their meaning; 1 and 2 are upstream's lz4mid, * faster and weaker than the shallow hash chain the fork used for them. */ +static_assert (LZ4HC_CLAMP_CLEVEL ==LZ4HC_CLEVEL_OPT_MIN ); +static int lz4hc_clamp_level (int compressionLevel) { -if (compressionLevel >=LZ4HC_CLEVEL_OPT_MIN ) -return LZ4HC_CLEVEL_OPT_MIN -1 ; +if (compressionLevel >=LZ4HC_CLAMP_CLEVEL ) +return LZ4HC_CLAMP_CLEVEL -1 ;return compressionLevel; }
Signature · 1 line
2.34.1
PATCH v2 15/15 MAINTAINERS: add an entry for the LZ4 compression library
In reply to Michal Wilczynskilib/lz4/ has never had one: get_maintainer.pl returns only the LKML fallback for every file in it, including include/linux/lz4.h, which eight subsystems build against.
The entry also takes lib/decompress_unlz4.c and its header, which decode LZ4 kernel images and initramfs through lib/lz4, the way XZ EMBEDDED covers its own equivalents, and crypto/lz4.c and crypto/lz4hc.c, the crypto API wrappers zswap uses, as ZSTD takes crypto/zstd.c.
This matters more now than it did. With the previous patches lib/lz4 is vendored upstream sources, and someone has to bump them to new upstream releases and decide what the kernel-side glue may do. I am willing to do that, so add myself as its maintainer.
--- MAINTAINERS | 10 ++++++++++ 1 file changed, 10 insertions(+)
MAINTAINERS +10 -0
@@ -15606,6 +15606,16 @@ S: Supported F: drivers/net/pcs/pcs-lynx.c F: include/linux/pcs-lynx.h +LZ4 COMPRESSION LIBRARY +M: Michal Wilczynski <[email protected]> +S: Maintained +F: crypto/lz4.c +F: crypto/lz4hc.c +F: include/linux/decompress/unlz4.h +F: include/linux/lz4.h +F: lib/decompress_unlz4.c +F: lib/lz4/ + M68K ARCHITECTURE M: Geert Uytterhoeven <[email protected]> L: [email protected]
Signature · 1 line
2.34.1
[email protected]
AI reviewRe: [PATCH v2 05/15] lib/lz4: backport upstream's -Wmissing-prototypes fix
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 10 lines
v1.10.0 defines
LZ4_loadDict_internal()inlz4.candLZ4HC_searchExtDict()inlz4hc.cwith external linkage and no prototype, which the kernel's -Wmissing-prototypes rejects. The first would also prevent linking oncelz4_compress.candlz4_decompress.cboth includelz4.c, later in this series, since each would define it.Neither can be forward declared static in the
lz4_deps.ha later patch adds, as the other bare helpers are, because their signatures use types declared inside the .c files.
Quoted 5 lines
Take the two hunks of upstream commit
5ef1f16929b5
("fix -Wmissing-prototypes warnings") that apply to the files we vendor. This goes away at the next re-sync.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
Signature · 1 line
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=5
[email protected]
AI reviewRe: [PATCH v2 06/15] lib/lz4: backport upstream's aarch64 fast decode loop enablement
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 7 lines
v1.10.0 leaves
LZ4_FAST_DEC_LOOPoff for aarch64 built with clang, after a slowdown reported on some Android phones in 2019 (upstream PR #707). An arm64 kernel built with clang therefore decodes with the slower loop.Upstream has since enabled it for all aarch64, in three unreleased commits:
Quoted 8 lines
commit
0aa33884faf5("[LZ4] Limit disablingLZ4_FAST_DEC_LOOPto aarch64+clang+android") commit51f8af506b4a("Fix missing endif")
commited86bc1ed802("AArch64: EnableLZ4_FAST_DEC_LOOPfor Android")Arm measured +3.5% to +15.6% on Cortex-A510 to X4 with clang. Take the
lz4.chunks of all three. This goes away at the next re-sync.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
Signature · 1 line
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=6
[email protected]
AI reviewRe: [PATCH v2 02/15] lib/lz4: remove LZ4_decompress_fast() and its variants
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 11 lines
LZ4_decompress_fast(),LZ4_decompress_fast_continue()andLZ4_decompress_fast_usingDict()have no users left. Upstream has deprecated all three since v1.9: they take only the decompressed size, so a corrupt or malicious stream has nothing to stop the decoder from reading past the end of its input.Remove them, their exports and their declarations in <
linux/lz4.h>, along with the two helpers only they used. Doing it before lib/lz4 moves to upstream LZ4 keeps them out of the glue that move adds.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 04/15] lib/lz4: import upstream LZ4 sources verbatim
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 7 lines
Add the four upstream files under
lib/lz4/upstream/without modification. Nothing builds them yet; a later patch adds the build environment.Copied without modification from the v1.10.0 release tag of
https://github.com/lz4/lz4, tagged 2024-07-21.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 09/15] arch: boot: put the LZ4 freestanding headers on the decompressor path
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 9 lines
lib/decompress_unlz4.cpullslib/lz4/lz4_decompress.cinto the pre-boot decompressor on these five arches. A later patch makes that file include the vendored LZ4 sources, which include ISO C headers that -nostdinc does not provide, so putlib/lz4/freestandingon the include path first.Only the one object that includes
decompress_unlz4.cgets it, so the rest of each boot directory keeps -nostdinc's view.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 03/15] zram: lz4hc: reset the dictionary stream once, not per page
In reply to Michal WilczynskiThank you for your contribution! Sashiko AI review found no new issues in this patch, but noticed 1 related pre-existing issue it does not introduce: - [Medium] zram: high-order memory allocation…
Thank you for your contribution! Sashiko AI review found no new issues in this patch, but noticed 1 related pre-existing issue it does not introduce:
- [Medium] zram: high-order memory allocation using kzalloc in lz4hc_create() [1]
--
commit 2f51683dc7418bdcd0730283cb7003d8754fcd5f
Author: Michal Wilczynski <[email protected]>
zram: lz4hc: reset the dictionary stream once, not per page
This commit moves the LZ4_resetStreamHC() call for dictionary-backed streams from lz4hc_compress() to lz4hc_create() so that the stream state is only reset once at creation time rather than on every compressed page.
drivers/block/zram/backend_lz4hc.c static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx) · line 76
Quoted 10 lines
drivers/block/zram/backend_lz4hc.c +1
-0@@ -72,6 +72,7 @@ static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx) zctx->cstrm =kzalloc_obj (*zctx->cstrm);if (!zctx->cstrm) goto error; +LZ4_resetStreamHC (zctx->cstrm, params->level); }
[Severity: Medium]
This problem wasn't introduced by this patch, but should zctx->cstrm be allocated with vmalloc() or kvzalloc() instead of kzalloc_obj() [1]?
LZ4_streamHC_t is 262,192 bytes (LZ4_STREAMHCSIZE), so kzalloc_obj() requests an order-7 physically contiguous allocation. Unlike the non-dictionary path right above, which uses vmalloc(LZ4HC_MEM_COMPRESS), this allocation can easily fail under normal memory fragmentation during zram initialization or CPU hotplug.
[1] https://sashiko.dev/#/bug/linux-78ebc045-5e81-4f0b-985e-99483d454b25
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AI reviewRe: [PATCH v2 07/15] lib/lz4: backport upstream's match length limit fix
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 14 lines
v1.10.0 lets a match length's extension bytes run to four bytes before the end of the block, which leaves room for only a token and three literals where the format requires five. The fork rejected such blocks, v1.10.0 decodes them: 1f 41 01 00 ff 00 30 7a 7a 7a decodes to 278 bytes instead of failing.
Upstream fixed this in
587ed9557708("add comments explainingread_variable_length()ilimit bounds, fix match length limit"), on top of aread_variable_length()rework v1.10.0 does not have. Both versions accept the same final ip for a given limit, so change the limit at the two match length call sites to iend - (1 + LASTLITERALS), as upstream does. This is one byte stricter than the fork; no compressor produces the blocks it newly rejects.
Quoted 3 lines
This goes away at the next re-sync.
Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 14/15] lib/lz4: replace lz4_kernel_api.h's prototypes with <linux/lz4.h>
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 10 lines
lz4_kernel_api.hcarried its own copy of the twenty public prototypes because it could not include <linux/lz4.h>, which defined the stream types that upstream's headers also define.The types are incomplete now, so it can. Two prototype lists for one ABI is a drift hazard: the entry points were built against one and their callers against the other, so no compiler ever saw both, and MODVERSIONS would not catch a mismatch either, since it hashes the exporter's view only. Now there is one list.
Quoted 6 lines
It also puts the public constants in scope of the entry points, so the size assertions can name them, and the HC level clamp can use
LZ4HC_CLAMP_CLEVEL,static_assertedequal to upstream'sLZ4HC_CLEVEL_OPT_MIN.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 10/15] lib/lz4: switch the compressor to the vendored sources
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 16 lines
Replace the forked compressor with thin entry points over the vendored
lz4.c.LZ4_compress_default(),LZ4_compress_fast()andLZ4_compress_destSize()keep the trailing wrkmem argument and forward to upstream's*_extState()functions; the rest are plain forwarders.Upstream's
LZ4_initStream()returns NULL for a misaligned workspace, whichLZ4_compress_fast_extState()dereferences andLZ4_compress_destSize_extState()ignores. Check the alignment in the entry points, warn once and fail the call. In-tree callers allocate withkmalloc()orvmalloc()and are not affected.Compressed output differs from the fork's on a small fraction of inputs by a byte or two; both decode each other's output. Compressing 4K blocks, upstream is 2-4% faster on kernel source and binaries and up to 9% slower on datagen.
Quoted 7 lines
LZ4_stream_tbecomes an incomplete type, as upstream declares it, so <linux/lz4.h> and upstream'slz4.hcan share a translation unit. The macros that laid out the forked structure go, andLZ4_MEM_COMPRESSkeeps its value, 16416. zram, the only caller usingsizeof(LZ4_stream_t), now allocatesLZ4_MEM_COMPRESSbytes.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 12/15] lib/lz4: widen LZ4_DECOMPRESS_INPLACE_MARGIN for the fast decode loop
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 12 lines
erofs decompresses a pcluster in place when the slack after the output is at least
LZ4_DECOMPRESS_INPLACE_MARGIN(compressed size), upstream's (compressedSize >> 8) + 32.That holds for the fork, which overshoots its output by at most 8 bytes. Upstream's
LZ4_FAST_DEC_LOOP, which the next patch brings in for x86 and arm64, copies in 32-byte steps and can overwrite input it has not read yet: of 172410 valid streams laid out as erofs does at exactly that margin, 3660 fail to decode, none with the fork. The worst needs (compressedSize >> 8) + 33. Images mkfs.erofs built did not hit this, but nothing in the format rules it out.
Quoted 5 lines
Use (compressedSize >> 8) + (compressedSize >> 15) + 36, which takes a 4K pcluster's margin from 48 to 52 bytes. Upstream's
lz4.hdefines the macro too, so undefine it first.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 11/15] lib/lz4: switch the HC compressor to the vendored sources
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 22 lines
Replace the forked LZ4HC with thin entry points over the vendored
lz4hc.c.Upstream routes levels 10 and up to its optimal parser, whose ~64K workspace the kernel cannot provide. Clamp those levels to 9 rather than reject them, so existing f2fs and zram settings keep working, and add
LZ4HC_CLAMP_CLEVELto <linux/lz4.h>. Document the clamp inf2fs.rst.Levels 1 and 2 now use upstream's lz4mid: on kernel source they are 50-84% faster for 4-9% larger output. Levels 3 to 9 compress the same, but at 4K are up to 15% slower on poorly compressible data, including at level 9, zram's lz4hc default.
LZ4_compress_HC()andLZ4_resetStreamHC()check the state's alignment like the compressor's entry points.
LZ4_streamHC_tbecomes incomplete and the macros that laid out the forked structure go.LZ4HC_MEM_COMPRESSgrows from 262192 to upstream's 262200,static_assertedagainstLZ4_STREAMHC_MINSIZE.lz4hc.cpulls in lz4.c's decoder tables, unused here when the fast decode loop is off, so silence -Wunused-const-variable for this object.
Quoted 4 lines
This retires commit
b08918fb3f27("lz4: do not export static symbol"):
the glue exports only the five LZ4HC entry points.Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 08/15] lib/lz4: add the build environment for the vendored sources
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 26 lines
lz4_deps.hmakes the vendored upstream sources build in the kernel. It gives every upstream entry point internal linkage, so an object carries only the codec it forwards, selects heap mode with failing allocators so LZ4HC's ~64K optimal-parser buffer stays off the stack, and renames the entry points the kernel re-exports so the kernel's own definitions can use the real names.LZ4LIB_VISIBILITYcarries__maybe_unusedfor the functions an object does not use.freestanding/ forwards the four ISO C headers upstream includes to their <linux/> equivalents.
lz4_kernel_api.hundoes the renaming; it carries its own copy of the exported prototypes until a later patch can include <linux/lz4.h> instead.Two settings upstream leaves to the build:
- Unaligned access goes through
memcpy()where the architecture has efficient unaligned access, and through packed structs, asget_unaligned()does, elsewhere. Left alone, upstream uses plain misaligned loads on ARMv6.- On ppc64le,
lz4.cmarks functions __attribute__((optimize("O2"))) for GCC, which drops command line options such as -fno-strict-aliasing for them; see commit080b6f407635("bpf: Don't rely on GCC __attribute__((optimize)) to disable GCSE").lz4_deps.hdefinesoptimize()to nothing for upstream's sources.
Quoted 3 lines
Nothing includes either header yet.
Signed-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 13/15] lib/lz4: switch the decompressor to the vendored sources
In reply to Michal WilczynskiSashiko has reviewed this patch and found no issues.
Quoted 15 lines
Replace the forked decompressor with thin entry points over the vendored
lz4.c; the API is signature-compatible, so every export is a plain forwarder.lz4defs.hhas no users left and goes.
lib/decompress_unlz4.cincludes this file before boot, together with <linux/lz4.h>, soLZ4_streamDecode_tbecomes incomplete as upstream declares it, andLZ4_MEM_DECOMPRESS(32) replaces theLZ4_STREAMDECODESIZEmacros.LZ4_COMPRESSBOUNDis defined by both headers and gets a guard; theLZ4_compressBound()wrapper goes, aslib/decompress_unlz4.cnow uses the macro.
LZ4_decompress_safe_partial()on a truncated block can now return the bytes decoded so far rather than an error, depending on where the cut falls; the kernel-doc says so.
Quoted 6 lines
[ ... ]
upstreamc5d6f8a8be39("fix #783"), v1.9.3
commit2d8867f3e083("lib: makeLZ4_decompress_safe_forceExtDict()static")
the static forward declaration inlz4_deps.hSigned-off-by Michal Wilczynski <[email protected]>
Sashiko has reviewed this patch and found no issues.
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AI reviewRe: [PATCH v2 01/15] lib/decompress_unlz4: use LZ4_decompress_safe_partial() before boot
In reply to Michal WilczynskiThank you for your contribution! Sashiko AI review found 3 potential issues to consider: - [Medium] lib/decompress_unlz4: unvalidated chunksize passed to decoder in unlz4() - [Low]…
Thank you for your contribution! Sashiko AI review found 3 potential issues to consider:
- [Medium] lib/decompress_unlz4: unvalidated chunksize passed to decoder in unlz4()
- [Low] lib/decompress_unlz4: partial decode skips full-block checks in unlz4()
- [Low] lib/decompress_unlz4: unlz4() does not check out_len == 0 at stream end
--
commit 8a11d492456e8edabb6dad4a7ecb828134c99572
Author: Michal Wilczynski <[email protected]>
lib/decompress_unlz4: use LZ4_decompress_safe_partial() before boot
This commit replaces LZ4_decompress_fast() with LZ4_decompress_safe_partial() in the pre-boot unlz4() path and checks that each chunk produces the expected output size.
Quoted 11 lines
lib/decompress_unlz4.c +1
-1@@ -151,14 +151,17 @@ STATIC inline int INIT unlz4(u8 *input, long in_len, } }#ifdef PREBOOT -if (out_len >= uncomp_chunksize) { +if (out_len >= uncomp_chunksize) dest_len = uncomp_chunksize;
lib/decompress_unlz4.c STATIC inline int INIT unlz4(u8 *input, long in_len, · line 161
Quoted 10 lines
lib/decompress_unlz4.c +4
-4- out_len -= dest_len; - }else +else dest_len = out_len; + out_len -= dest_len; - ret =LZ4_decompress_fast (inp, outp, dest_len); - chunksize = ret; + ret =LZ4_decompress_safe_partial (inp, outp, chunksize, + dest_len, dest_len);
[Severity: Medium]
Can a truncated or corrupted chunk header cause LZ4_decompress_safe_partial() to read past the end of the input buffer?
Previously, LZ4_decompress_fast() ignored chunksize and overwrote it with the consumed byte count before the !fill path checked size -= chunksize at the bottom of the loop:
lib/decompress_unlz4.c:unlz4() {
...
if (!fill) {
inp += 4;
size -= 4;
} else {
...
if (!fill) {
size -= chunksize;
if (size == 0)
break;
else if (size < 0) {
error("data corrupted");
goto exit_2;
}
inp += chunksize;
}
}Passing chunksize from get_unaligned_le32(inp) directly to LZ4_decompress_safe_partial() before checking it against size lets the decoder read past input + in_len when chunksize > size, or pass a negative compressedSize when chunksize >= 0x80000000.
lib/decompress_unlz4.c STATIC inline int INIT unlz4(u8 *input, long in_len, · line 164
Quoted 3 lines
lib/decompress_unlz4.c +3
-0+/* A chunk once the image's stated size is reached is corrupt. */ +if (!dest_len || ret != (int )dest_len) + ret =-1 ;
[Severity: Low]
Should this call LZ4_decompress_safe(inp, outp, chunksize, dest_len) instead of LZ4_decompress_safe_partial()?
In LZ4_decompress_generic(), partial_decode mode clamps literal runs and matches that would exceed dest_len and stops as soon as dest_len bytes are written without verifying that all chunksize input bytes were consumed. A corrupted chunk that expands beyond dest_len or leaves trailing bytes inside chunksize will still return dest_len and pass this check.
[Severity: Low]
Can a truncated image that ends on a chunk boundary still return success when out_len has not reached zero?
This check rejects chunks that decode short or arrive after out_len reaches zero, but if the input stream ends early between chunks (or has chunksize == 0), the loop jumps to exit_3 and returns 0 with out_len > 0.
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kernel test robot
build botRe: [PATCH v2 10/15] lib/lz4: switch the compressor to the vendored sources
In reply to Michal Wilczynskikernel test robot noticed the following build errors:
Hi Michal,
kernel test robot noticed the following build errors:
[auto build test ERROR on 93f51579e7df248780214094418f205253383cc5]
url: https://github.com/intel-lab-lkp/linux/commits/Michal-Wilczynski/lib-decompress_unlz4-use-LZ4_decompress_safe_partial-before-boot/20261106-154241 base: 93f51579e7df248780214094418f205253383cc5 patch link: https://lore.kernel.org/r/20261106-lz4-vendor-upstream-v2-10-ee04c3f0d7dc%40samsung.com patch subject: [PATCH v2 10/15] lib/lz4: switch the compressor to the vendored sources config: arc-allmodconfig (https://download.01.org/0day-ci/archive/20261107/[email protected]/config) compiler: arc-linux-gcc (GCC) 16.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261107/[email protected]/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
All errors (new ones prefixed by >>):
In file included from include/linux/rcupdate.h:27,
from include/linux/rbtree.h:24,
from include/linux/mm_types.h:11,
from include/linux/mmzone.h:22,
from include/linux/gfp.h:7,
from include/linux/umh.h:4,
from include/linux/kmod.h:9,
from include/linux/module.h:18,
from lib/lz4/lz4_compress.c:29:
include/linux/sched.h: In function 'is_percpu_thread':
>> include/linux/sched.h:1860:17: error: 'current' undeclared (first use in this function)
1860 | return (current->flags & PF_NO_SETAFFINITY) &&
| ^~~~~~~
include/linux/sched.h:1860:17: note: each undeclared identifier is reported only once for each function it appears in
include/linux/sched.h: In function 'current_restore_flags':
include/linux/sched.h:1918:9: error: 'current' undeclared (first use in this function)
1918 | current->flags &= ~flags;
| ^~~~~~~
include/linux/sched.h: In function 'set_need_resched_current':
include/linux/sched.h:2127:30: error: 'current' undeclared (first use in this function)
2127 | set_tsk_need_resched(current);
| ^~~~~~~
In file included from include/asm-generic/bug.h:7,
from arch/arc/include/asm/bug.h:30,
from include/linux/bug.h:5,
from lib/lz4/lz4_compress.c:27:
include/linux/sched.h: In function '__set_task_blocked_on':
include/linux/sched.h:2231:27: error: 'current' undeclared (first use in this function)
2231 | WARN_ON_ONCE(p != current);
| ^~~~~~~
include/linux/once_lite.h:28:41: note: in definition of macro 'DO_ONCE_LITE_IF'
28 | bool __ret_do_once = !!(condition); \
| ^~~~~~~~~
include/linux/sched.h:2231:9: note: in expansion of macro 'WARN_ON_ONCE'
2231 | WARN_ON_ONCE(p != current);
| ^~~~~~~~~~~~
In file included from include/linux/nodemask.h:92,
from include/linux/numa.h:6,
from include/linux/cpumask.h:15,
from include/linux/smp.h:13,
from include/linux/interrupt_rc.h:17,
from include/linux/spinlock.h:60,
from include/linux/mmzone.h:8:
include/linux/sched.h: In function 'alloc_tag_save':
include/linux/sched.h:2361:14: error: 'current' undeclared (first use in this function)
2361 | swap(current->alloc_tag, tag);
| ^~~~~~~
include/linux/minmax.h:308:21: note: in definition of macro 'swap'
308 | do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
| ^
>> include/linux/minmax.h:308:52: error: assignment to 'struct alloc_tag *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
308 | do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
| ^
include/linux/sched.h:2361:9: note: in expansion of macro 'swap'
2361 | swap(current->alloc_tag, tag);
| ^~~~
include/linux/sched.h: In function 'alloc_tag_restore':
include/linux/sched.h:2368:14: error: 'current' undeclared (first use in this function)
2368 | WARN(current->alloc_tag != tag, "current->alloc_tag was changed:\n");
| ^~~~~~~
include/asm-generic/bug.h:164:32: note: in definition of macro 'WARN'
164 | int __ret_warn_on = !!(condition); \
| ^~~~~~~~~
In file included from <command-line>:
include/linux/rcupdate.h: In function 'cond_resched_tasks_rcu_qs':
>> include/linux/rcupdate.h:226:22: error: 'current' undeclared (first use in this function)
226 | rcu_tasks_qs(current, false);
| ^~~~~~~
include/linux/compiler_types.h:682:23: note: in definition of macro '__compiletime_assert'
682 | if (!(condition)) \
| ^~~~~~~~~
include/linux/compiler_types.h:702:9: note: in expansion of macro '_compiletime_assert'
702 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert'
36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
| ^~~~~~~~~~~~~~~~~~
include/asm-generic/rwonce.h:36:28: note: in expansion of macro '__native_word'
36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
| ^~~~~~~~~~~~~
include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type'
49 | compiletime_assert_rwonce_type(x); \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/rcupdate.h:185:35: note: in expansion of macro 'READ_ONCE'
185 | if (!(preempt) && READ_ONCE((t)->rcu_tasks_holdout)) \
| ^~~~~~~~~
include/linux/rcupdate.h:197:34: note: in expansion of macro 'rcu_tasks_classic_qs'
197 | #define rcu_tasks_qs(t, preempt) rcu_tasks_classic_qs((t), (preempt))
| ^~~~~~~~~~~~~~~~~~~~
include/linux/rcupdate.h:226:9: note: in expansion of macro 'rcu_tasks_qs'
226 | rcu_tasks_qs(current, false);
| ^~~~~~~~~~~~
In file included from include/linux/local_lock.h:5,
from include/linux/mmzone.h:24:
include/linux/local_lock_internal.h: In function 'local_lock_acquire':
>> include/linux/local_lock_internal.h:48:20: error: 'current' undeclared (first use in this function)
48 | l->owner = current;
| ^~~~~~~
include/linux/local_lock_internal.h: In function 'local_trylock_acquire':
include/linux/local_lock_internal.h:55:20: error: 'current' undeclared (first use in this function)
55 | l->owner = current;
| ^~~~~~~
In file included from include/linux/build_bug.h:5,
from lib/lz4/lz4_deps.h:18,
from lib/lz4/lz4_compress.c:16:
include/linux/local_lock_internal.h: In function 'local_lock_release':
include/linux/local_lock_internal.h:60:41: error: 'current' undeclared (first use in this function)
60 | DEBUG_LOCKS_WARN_ON(l->owner != current);
| ^~~~~~~
include/linux/compiler.h:77:45: note: in definition of macro 'unlikely'
77 | # define unlikely(x) __builtin_expect(!!(x), 0)
| ^
include/linux/local_lock_internal.h:60:9: note: in expansion of macro 'DEBUG_LOCKS_WARN_ON'
60 | DEBUG_LOCKS_WARN_ON(l->owner != current);
| ^~~~~~~~~~~~~~~~~~~
include/linux/sched/mm.h: In function 'current_gfp_context':
>> include/linux/sched/mm.h:250:41: error: 'current' undeclared (first use in this function)
250 | unsigned int pflags = READ_ONCE(current->flags);
| ^~~~~~~
include/linux/compiler_types.h:682:23: note: in definition of macro '__compiletime_assert'
682 | if (!(condition)) \
| ^~~~~~~~~
include/linux/compiler_types.h:702:9: note: in expansion of macro '_compiletime_assert'
702 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
include/asm-generic/rwonce.h:36:9: note: in expansion of macro 'compiletime_assert'
36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
| ^~~~~~~~~~~~~~~~~~
include/asm-generic/rwonce.h:36:28: note: in expansion of macro '__native_word'
36 | compiletime_assert(__native_word(t) || sizeof(t) == sizeof(long long), \
| ^~~~~~~~~~~~~
include/asm-generic/rwonce.h:49:9: note: in expansion of macro 'compiletime_assert_rwonce_type'
49 | compiletime_assert_rwonce_type(x); \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/sched/mm.h:250:31: note: in expansion of macro 'READ_ONCE'
250 | unsigned int pflags = READ_ONCE(current->flags);
| ^~~~~~~~~
include/linux/sched/mm.h: In function 'memalloc_retry_wait':
include/linux/sched.h:170:17: error: 'current' undeclared (first use in this function)
170 | current->task_state_change = _THIS_IP_; \
| ^~~~~~~
include/linux/sched.h:242:17: note: in expansion of macro 'debug_normal_state_change'
242 | debug_normal_state_change((state_value)); \
| ^~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/sched/mm.h:293:9: note: in expansion of macro '__set_current_state'
293 | __set_current_state(TASK_UNINTERRUPTIBLE);
| ^~~~~~~~~~~~~~~~~~~
In file included from include/linux/xarray.h:21,
from include/linux/radix-tree.h:21,
from include/linux/idr.h:15,
from include/linux/kernfs.h:12,
from include/linux/sysfs.h:16,
from include/linux/kobject.h:20,
from include/linux/module.h:22:
include/linux/sched/mm.h: In function 'might_alloc':
include/linux/sched/mm.h:319:13: error: 'current' undeclared (first use in this function)
319 | if (current->flags & PF_MEMALLOC)
| ^~~~~~~
include/linux/sched/mm.h: In function 'memalloc_flags_save':
include/linux/sched/mm.h:334:30: error: 'current' undeclared (first use in this function)
334 | unsigned oldflags = ~current->flags & flags;
| ^~~~~~~
include/linux/sched/mm.h: In function 'memalloc_flags_restore':
include/linux/sched/mm.h:341:9: error: 'current' undeclared (first use in this function)
341 | current->flags &= ~flags;
| ^~~~~~~
include/linux/sched/mm.h: In function 'set_active_memcg':
include/linux/sched/mm.h:499:23: error: 'current' undeclared (first use in this function)
499 | old = current->active_memcg;
| ^~~~~~~
include/linux/sched/mm.h: In function 'membarrier_mm_sync_core_before_usermode':
include/linux/sched/mm.h:543:13: error: 'current' undeclared (first use in this function)
543 | if (current->mm != mm)
| ^~~~~~~vim +308 include/linux/minmax.h
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 285)
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 286) /**
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 287) * in_range - Determine if a value lies within a range.
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 288) * @val: Value to test.
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 289) * @start: First value in range.
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 290) * @len: Number of values in range.
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 291) *
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 292) * This is more efficient than "if (start <= val && val < (start + len))".
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 293) * It also gives a different answer if @start + @len overflows the size of
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 294) * the type by a sufficient amount to encompass @val. Decide for yourself
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 295) * which behaviour you want, or prove that start + len never overflow.
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 296) * Do not blindly replace one form with the other.
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 297) */
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 298) #define in_range(val, start, len) \
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 299) ((sizeof(start) | sizeof(len) | sizeof(val)) <= sizeof(u32) ? \
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 300) in_range32(val, start, len) : in_range64(val, start, len))
f9bff0e31881d03 Matthew Wilcox (Oracle 2023-08-02 301)
b296a6d53339a79 Andy Shevchenko 2020-10-15 302 /**
b296a6d53339a79 Andy Shevchenko 2020-10-15 303 * swap - swap values of @a and @b
b296a6d53339a79 Andy Shevchenko 2020-10-15 304 * @a: first value
b296a6d53339a79 Andy Shevchenko 2020-10-15 305 * @b: second value
b296a6d53339a79 Andy Shevchenko 2020-10-15 306 */
b296a6d53339a79 Andy Shevchenko 2020-10-15 307 #define swap(a, b) \
b296a6d53339a79 Andy Shevchenko 2020-10-15 @308 do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
b296a6d53339a79 Andy Shevchenko 2020-10-15 309 --
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Sergey Senozhatsky
maintainerRe: [PATCH v2 03/15] zram: lz4hc: reset the dictionary stream once, not per page
In reply to [email protected]Quoted 16 lines · On (26/11/06 14:49), [email protected] wrote:
Thank you for your contribution! Sashiko AI review found no new issues in this patch, but noticed 1 related pre-existing issue it does not introduce:
- [Medium] zram: high-order memory allocation using kzalloc inlz4hc_create()[1]
--commit
2f51683dc7418bdcd0730283cb7003d8754fcd5f
Author: Michal Wilczynski <[email protected]>zram: lz4hc: reset the dictionary stream once, not per page
This commit moves the
LZ4_resetStreamHC()call for dictionary-backed streams fromlz4hc_compress()tolz4hc_create()so that the stream state is only reset once at creation time rather than on every compressed page.
Quoted 14 lines
drivers/block/zram/backend_lz4hc.c static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx) · line 76
Quoted 10 lines
drivers/block/zram/backend_lz4hc.c +1
-0@@ -72,6 +72,7 @@ static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx) zctx->cstrm =kzalloc_obj (*zctx->cstrm);if (!zctx->cstrm) goto error; +LZ4_resetStreamHC (zctx->cstrm, params->level); }[Severity: Medium]
This problem wasn't introduced by this patch, but shouldzctx->cstrmbe allocated withvmalloc()orkvzalloc()instead ofkzalloc_obj()[1]?
That's how I have it in my local tree - vmalloc(LZ4HC_MEM_COMPRESS). Michal, I suppose you don't base the series on top of linux-next or Andrew's tree?
We reset the stream when we setup params, so I don't think we need to do anything in lz4hc_create().
Sergey Senozhatsky
maintainerRe: [PATCH v2 10/15] lib/lz4: switch the compressor to the vendored sources
In reply to Michal WilczynskiOn (26/11/06 15:42), Michal Wilczynski wrote:
[..]
Quoted 23 lines
drivers/block/zram/backend_lz4.c +2
-2@@ -42,7 +42,7 @@ static int lz4_setup_params(struct zcomp_params *params)if (!params->dict || !params->dict_sz)return 0 ; - dict_stream =kzalloc_obj (*dict_stream); + dict_stream =kzalloc (LZ4_MEM_COMPRESS ,GFP_KERNEL );if (!dict_stream)return -ENOMEM ;@@ -88,7 +88,7 @@ static int lz4_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->dstrm) goto error; - zctx->cstrm =kzalloc_obj (*zctx->cstrm); + zctx->cstrm =kzalloc (LZ4_MEM_COMPRESS ,GFP_KERNEL );if (!zctx->cstrm) goto error; }
drivers/block/zram/backend_lz4.c static int lz4_compress(struct zcomp_params *params, struct zcomp_ctx *ctx, · line 118
Quoted 8 lines
drivers/block/zram/backend_lz4.c +1
-1@@ -112,7 +112,7 @@ static int lz4_compress(struct zcomp_params *params, struct zcomp_ctx *ctx, zctx->mem); }else {/* Cstrm needs to be reset */ -memcpy (zctx->cstrm, params->drv_data,sizeof (*zctx->cstrm)); +memcpy (zctx->cstrm, params->drv_data,LZ4_MEM_COMPRESS ); ret =LZ4_compress_fast_continue (zctx->cstrm, req->src, req->dst, req->src_len, req->dst_len, params->level);
The zram code here is outdated, it has been reworked quite a bit (patches are in linux-next and Andrew's trees).
Sergey Senozhatsky
maintainerRe: [PATCH v2 13/15] lib/lz4: switch the decompressor to the vendored sources
In reply to Michal WilczynskiOn (26/11/06 15:42), Michal Wilczynski wrote:
[..]
Quoted 18 lines
drivers/block/zram/backend_lz4.c +1
-1@@ -84,7 +84,7 @@ static int lz4_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->mem) goto error; }else { - zctx->dstrm =kzalloc_obj (*zctx->dstrm); + zctx->dstrm =kzalloc (LZ4_MEM_DECOMPRESS ,GFP_KERNEL );if (!zctx->dstrm) goto error;drivers/block/zram/backend_lz4hc.c +0
-0
drivers/block/zram/backend_lz4hc.c static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx) · line 70
Quoted 7 lines
drivers/block/zram/backend_lz4hc.c +1
-1@@ -65,7 +65,7 @@ static int lz4hc_create(struct zcomp_params *params, struct zcomp_ctx *ctx)if (!zctx->mem) goto error; }else { - zctx->dstrm =kzalloc_obj (*zctx->dstrm); + zctx->dstrm =kzalloc (LZ4_MEM_DECOMPRESS ,GFP_KERNEL );if (!zctx->dstrm) goto error;
Ditto, outdated zram code.
My ask would be to not squash zram changes with lz4 changes, when (iff) possible.