Update LZ4 compression library to the latest stable version 1.10.0
for improved performance and bug fixes.
Commit:
a049f5b4bd (diff-f27c1e4d68)
Changes:
- Upgrade LZ4 from [previous version] to 1.10.0
- Remove lz4hc (high compression) variant to simplify codebase
- Update API calls to match new LZ4 interface
- Maintain compatibility with existing ZRAM integration
Benefits:
- Enhanced compression/decompression performance
- Reduced memory usage during compression
- Latest security fixes and stability improvements
- Simplified maintenance without lz4hc complexity
The removal of lz4hc reduces kernel size while standard LZ4 provides
sufficient compression performance for most use cases.
Co-authored-by: JackA1ltman <cs2dtzq@163.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
JackA1ltmanauthored and Sorayukiicommited 2026-05-15 18:07:05 +07:00
This fixes the following warnings by sparse:
../lib/lz4/lz4_compress.c:838:5: warning: symbol 'LZ4_compress_fast_extState' was not declared. Should it be static?
../lib/lz4/lz4_decompress.c:141:8: warning: symbol 'read_long_length_no_check' was not declared. Should it be static?
../lib/lz4/lz4_decompress.c:904:5: warning: symbol 'LZ4_decompress_fast' was not declared. Should it be static?
../lib/lz4/lz4_decompress.c:931:5: warning: symbol 'LZ4_decompress_safe_forceExtDict' was not declared. Should it be static?
../lib/lz4/lz4_decompress.c:1052:5: warning: symbol 'LZ4_decompress_fast_continue' was not declared. Should it be static?
../lib/lz4/lz4_decompress.c:1099:5: warning: symbol 'LZ4_decompress_safe_usingDict' was not declared. Should it be static?
../lib/lz4/lz4_decompress.c:1118:5: warning: symbol 'LZ4_decompress_fast_usingDict' was not declared. Should it be static?
Since some of the functions have been marked as static now, there is no need to export them.
Remove the redundant export symbols too.
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
Change-Id: Icc09fcf5dfed0f37cd36b3a960fbb660d2d8824e
(cherry picked from commit 94824e12387f857107300e7069420cbcca781f44)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Tashfin Shakeer Rhythmauthored and Sorayukiicommited 2026-05-15 18:07:04 +07:00
Update lz4 module using official repository from revision [1].
Keep in mind lz4hc wasn't updated thus it is not used. It may not
compile anymore.
[1]: 4ebe313e00
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
Change-Id: I51a35b54039c6a67f653ccd9f80ccbec8e3cf759
(cherry picked from commit 6961738d952fd9b5e43852700cec19154c71672a)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Andrzej Perczakauthored and Sorayukiicommited 2026-05-15 18:07:04 +07:00
We will update the lz4 module using its official repository.
The changes can collide with our modifications and backports.
Make some way for new codes and that's why, revert a few patches.
This reverts the following commits:
ad28920b5ab5 ("BACKPORT: lz4: fix LZ4_decompress_safe_partial read out of bound")
7151d98737e1 ("lib/lz4/lz4_decompress.c: document deliberate use of `&'")
5d136a311f8e ("lib/lz4: explicitly support in-place decompression")
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
Change-Id: Iffd0bfe41c6293c350c4561d1483d3c1a3909fcb
(cherry picked from commit 0962880fcdd812646ad16f3d0f2be3432246e77d)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Tashfin Shakeer Rhythmauthored and Sorayukiicommited 2026-05-15 18:07:04 +07:00
When partialDecoding, it is EOF if we've either filled the output buffer
or can't proceed with reading an offset for following match.
In some extreme corner cases when compressed data is suitably corrupted,
UAF will occur. As reported by KASAN [1], LZ4_decompress_safe_partial
may lead to read out of bound problem during decoding. lz4 upstream has
fixed it [2] and this issue has been disscussed here [3] before.
current decompression routine was ported from lz4 v1.8.3, bumping
lib/lz4 to v1.9.+ is certainly a huge work to be done later, so, we'd
better fix it first.
[1] https://lore.kernel.org/all/000000000000830d1205cf7f0477@google.com/
[2] c5d6f8a8be#
[3] https://lore.kernel.org/all/CC666AE8-4CA4-4951-B6FB-A2EFDE3AC03B@fb.com/
Link: https://lkml.kernel.org/r/20211111105048.2006070-1-guoxuenan@huawei.com
Reported-by: syzbot+63d688f1d899c588fb71@syzkaller.appspotmail.com
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Change-Id: Ieee18b9d9fb34b74d4e702719eb0c9d50f91c21d
Reviewed-by: Nick Terrell <terrelln@fb.com>
Acked-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Cc: Yann Collet <cyan@fb.com>
Cc: Chengyang Fan <cy.fan@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ Tashar02: Backport to k4.19 ]
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
(cherry picked from commit 20e35ea2e815e8ca1290151cc9036733ac3d09e7)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Guo Xuenanauthored and Sorayukiicommited 2026-05-15 18:07:03 +07:00
LZ4 final literal copy could be overlapped when doing
in-place decompression, so it's unsafe to just use memcpy()
on an optimized memcpy approach but memmove() instead.
Upstream LZ4 has updated this years ago [1] (and the impact
is non-sensible [2] plus only a few bytes remain), this commit
just synchronizes LZ4 upstream code to the kernel side as well.
It can be observed as EROFS in-place decompression failure
on specific files when X86_FEATURE_ERMS is unsupported,
memcpy() optimization of commit 59daa706fb ("x86, mem:
Optimize memcpy by avoiding memory false dependece") will
be enabled then.
Currently most modern x86-CPUs support ERMS, these CPUs just
use "rep movsb" approach so no problem at all. However, it can
still be verified with forcely disabling ERMS feature...
arch/x86/lib/memcpy_64.S:
ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
- "jmp memcpy_erms", X86_FEATURE_ERMS
+ "jmp memcpy_orig", X86_FEATURE_ERMS
We didn't observe any strange on arm64/arm/x86 platform before
since most memcpy() would behave in an increasing address order
("copy upwards" [3]) and it's the correct order of in-place
decompression but it really needs an update to memmove() for sure
considering it's an undefined behavior according to the standard
and some unique optimization already exists in the kernel.
[1] 33cb8518ac
[2] https://github.com/lz4/lz4/pull/717#issuecomment-497818921
[3] https://sourceware.org/bugzilla/show_bug.cgi?id=12518
Link: https://lkml.kernel.org/r/20201122030749.2698994-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
Change-Id: Id3274d42bd85c6d4d493f9a269cf5be4e0b17074
Reviewed-by: Nick Terrell <terrelln@fb.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Li Guifu <bluce.liguifu@huawei.com>
Cc: Guo Xuenan <guoxuenan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Oktapra Amtono <oktapra.amtono@gmail.com>
Signed-off-by: Anush02198 <Anush.4376@gmail.com>
Signed-off-by: Divyanshu-Modi <divyan.m05@gmail.com>
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
(cherry picked from commit 50a8262855642392b5471cb7c0dd8e9dae9531bf)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Gao Xiangauthored and Sorayukiicommited 2026-05-15 18:07:03 +07:00
This patch replaces all memcpy() calls with LZ4_memcpy() which calls
__builtin_memcpy() so the compiler can inline it.
LZ4 relies heavily on memcpy() with a constant size being inlined. In x86
and i386 pre-boot environments memcpy() cannot be inlined because memcpy()
doesn't get defined as __builtin_memcpy().
An equivalent patch has been applied upstream so that the next import
won't lose this change [1].
I've measured the kernel decompression speed using QEMU before and after
this patch for the x86_64 and i386 architectures. The speed-up is about
10x as shown below.
Code Arch Kernel Size Time Speed
v5.8 x86_64 11504832 B 148 ms 79 MB/s
patch x86_64 11503872 B 13 ms 885 MB/s
v5.8 i386 9621216 B 91 ms 106 MB/s
patch i386 9620224 B 10 ms 962 MB/s
I also measured the time to decompress the initramfs on x86_64, i386, and
arm. All three show the same decompression speed before and after, as
expected.
[1] https://github.com/lz4/lz4/pull/890
Signed-off-by: Nick Terrell <terrelln@fb.com>
Change-Id: I5764cb0c570fb384355d1e6d4669b415eb88c516
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Link: http://lkml.kernel.org/r/20200803194022.2966806-1-nickrterrell@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Adam W. Willis <return.of.octobot@gmail.com>
Signed-off-by: Oktapra Amtono <oktapra.amtono@gmail.com>
Signed-off-by: Anush02198 <Anush.4376@gmail.com>
Signed-off-by: Divyanshu-Modi <divyan.m05@gmail.com>
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
(cherry picked from commit 79cb95ee6f19213938de8ca61403a51d8bd4d5c2)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Nick Terrellauthored and Sorayukiicommited 2026-05-15 18:07:03 +07:00
Update the LZ4 compression module based on LZ4 v1.8.3 in order for the
erofs file system to use the newest LZ4_decompress_safe_partial() which
can now decode exactly the nb of bytes requested [1] to take place of the
open hacked code in the erofs file system itself.
Currently, apart from the erofs file system, no other users use
LZ4_decompress_safe_partial, so no worry about the interface.
In addition, LZ4 v1.8.x boosts up decompression speed compared to the
current code which is based on LZ4 v1.7.3, mainly due to shortcut
optimization for the specific common LZ4-sequences [2].
lzbench testdata (tested in kirin710, 8 cores, 4 big cores
at 2189Mhz, 2GB DDR RAM at 1622Mhz, with enwik8 testdata [3]):
Compressor name Compress. Decompress. Compr. size Ratio Filename
memcpy 5004 MB/s 4924 MB/s 100000000 100.00 enwik8
lz4hc 1.7.3 -9 12 MB/s 653 MB/s 42203253 42.20 enwik8
lz4hc 1.8.0 -9 12 MB/s 908 MB/s 42203096 42.20 enwik8
lz4hc 1.8.3 -9 11 MB/s 965 MB/s 42203094 42.20 enwik8
[1] https://github.com/lz4/lz4/issues/56608d347b5b2
[2] v1.8.1 perf: slightly faster compression and decompression speed
a31b7058cb
v1.8.2 perf: slightly faster HC compression and decompression speed
45f8603aae1a191b3f8d
[3] http://mattmahoney.net/dc/textdata.htmlhttp://mattmahoney.net/dc/enwik8.zip
Link: http://lkml.kernel.org/r/1537181207-21932-1-git-send-email-gaoxiang25@huawei.com
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Change-Id: I55a97dd11dc521f094e2d1586d8e97eecc74fff3
Tested-by: Guo Xuenan <guoxuenan@huawei.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Fang Wei <fangwei1@huawei.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: <weidu.du@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: celtare21 <celtare21@gmail.com>
Signed-off-by: sohamxda7 <sensoham135@gmail.com>
Signed-off-by: Oktapra Amtono <oktapra.amtono@gmail.com>
Signed-off-by: Anush02198 <Anush.4376@gmail.com>
Signed-off-by: Divyanshu-Modi <divyan.m05@gmail.com>
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
(cherry picked from commit 04840bfd0a7bbd370794e90d44e5b2c2e4974b6b)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Gao Xiangauthored and Sorayukiicommited 2026-05-15 18:07:03 +07:00
Don't populate the read-only arrays dec32table and dec64table on the
stack, instead make them both static const. Makes the object code
smaller by over 10K bytes:
Before:
text data bss dec hex filename
31500 0 0 31500 7b0c lib/lz4/lz4_decompress.o
After:
text data bss dec hex filename
20237 176 0 20413 4fbd lib/lz4/lz4_decompress.o
(gcc version 7.2.0 x86_64)
Link: http://lkml.kernel.org/r/20170921221939.20820-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Change-Id: I3f539a66bfa089a1a8a67af3a710582c0c91499a
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 8cb5d7482810b7eb1bb05bf4f71bc93ce35e5896)
Signed-off-by: TogoFire <togofire@mailfence.com>
Signed-off-by: Kanishk <kanishkthederp@gmail.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Colin Ian Kingauthored and Sorayukiicommited 2026-05-15 18:07:03 +07:00
Remove the functions introduced as wrappers for providing backwards
compatibility to the prior LZ4 version. They're not needed anymore
since there's no callers left.
Link: http://lkml.kernel.org/r/1486321748-19085-6-git-send-email-4sschmid@informatik.uni-hamburg.de
Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Cc: Bongkyu Kim <bongkyu.kim@lge.com>
Cc: Rui Salvaterra <rsalvaterra@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: kdrag0n <dragon@khronodragon.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Sven Schmidtauthored and Sorayukiicommited 2026-05-15 18:07:02 +07:00
Max output size can be larger than the source length if the input data
is 'too' random. This is normal and thus should be allowed since the
caller is expected to have the actual size of the output written to be
updated via the dst_len variable.
Bug: 111209481
Change-Id: I44a8abb6fb55936f2fd47616954341ba6b0d62ec
Signed-off-by: David Lin <dtwlin@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
David Linauthored and Sorayukiicommited 2026-05-15 18:07:02 +07:00
Patch series "Update LZ4 compressor module", v7.
This patchset updates the LZ4 compression module to a version based on
LZ4 v1.7.3 allowing to use the fast compression algorithm aka LZ4 fast
which provides an "acceleration" parameter as a tradeoff between high
compression ratio and high compression speed.
We want to use LZ4 fast in order to support compression in lustre and
(mostly, based on that) investigate data reduction techniques in behalf
of storage systems.
Also, it will be useful for other users of LZ4 compression, as with LZ4
fast it is possible to enable applications to use fast and/or high
compression depending on the usecase. For instance, ZRAM is offering a
LZ4 backend and could benefit from an updated LZ4 in the kernel.
LZ4 homepage: http://www.lz4.org/
LZ4 source repository: https://github.com/lz4/lz4 Source version: 1.7.3
Benchmark (taken from [1], Core i5-4300U @1.9GHz):
----------------|--------------|----------------|----------
Compressor | Compression | Decompression | Ratio
----------------|--------------|----------------|----------
memcpy | 4200 MB/s | 4200 MB/s | 1.000
LZ4 fast 50 | 1080 MB/s | 2650 MB/s | 1.375
LZ4 fast 17 | 680 MB/s | 2220 MB/s | 1.607
LZ4 fast 5 | 475 MB/s | 1920 MB/s | 1.886
LZ4 default | 385 MB/s | 1850 MB/s | 2.101
[1] http://fastcompression.blogspot.de/2015/04/sampling-or-faster-lz4.html
[PATCH 1/5] lib: Update LZ4 compressor module
[PATCH 2/5] lib/decompress_unlz4: Change module to work with new LZ4 module version
[PATCH 3/5] crypto: Change LZ4 modules to work with new LZ4 module version
[PATCH 4/5] fs/pstore: fs/squashfs: Change usage of LZ4 to work with new LZ4 version
[PATCH 5/5] lib/lz4: Remove back-compat wrappers
This patch (of 5):
Update the LZ4 kernel module to LZ4 v1.7.3 by Yann Collet. The kernel
module is inspired by the previous work by Chanho Min. The updated LZ4
module will not break existing code since the patchset contains
appropriate changes.
API changes:
New method LZ4_compress_fast which differs from the variant available in
kernel by the new acceleration parameter, allowing to trade compression
ratio for more compression speed and vice versa.
LZ4_decompress_fast is the respective decompression method, featuring a
very fast decoder (multiple GB/s per core), able to reach RAM speed in
multi-core systems. The decompressor allows to decompress data
compressed with LZ4 fast as well as the LZ4 HC (high compression)
algorithm.
Also the useful functions LZ4_decompress_safe_partial and
LZ4_compress_destsize were added. The latter reverses the logic by
trying to compress as much data as possible from source to dest while
the former aims to decompress partial blocks of data.
A bunch of streaming functions were also added which allow
compressig/decompressing data in multiple steps (so called "streaming
mode").
The methods lz4_compress and lz4_decompress_unknownoutputsize are now
known as LZ4_compress_default respectivley LZ4_decompress_safe. The old
methods will be removed since there's no callers left in the code.
Bug: 111209481
[arnd@arndb.de: fix KERNEL_LZ4 support]
Link: http://lkml.kernel.org/r/20170208211946.2839649-1-arnd@arndb.de
[akpm@linux-foundation.org: simplify]
[akpm@linux-foundation.org: fix the simplification]
[4sschmid@informatik.uni-hamburg.de: fix performance regressions]
Link: http://lkml.kernel.org/r/1486898178-17125-2-git-send-email-4sschmid@informatik.uni-hamburg.de
[4sschmid@informatik.uni-hamburg.de: v8]
Link: http://lkml.kernel.org/r/1487182598-15351-2-git-send-email-4sschmid@informatik.uni-hamburg.de
Link: http://lkml.kernel.org/r/1486321748-19085-2-git-send-email-4sschmid@informatik.uni-hamburg.de
Signed-off-by: Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Bongkyu Kim <bongkyu.kim@lge.com>
Cc: Rui Salvaterra <rsalvaterra@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 4e1a33b105ddf201f66dcc44490c6086a25eca0b)
Change-Id: Ic9230a2534573f74a29eb5004a20cf20375fdfeb
Signed-off-by: Martin Liu <liumartin@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Sven Schmidtauthored and Sorayukiicommited 2026-05-15 18:07:02 +07:00
This reverts commit 529ada21ff.
In order to directly merge new LZ4 module from upstream
revert the commit to solve the conflict.
Bug: 111209481
Change-Id: I19c3310f1941114b159f4b79766022104729fcfe
Signed-off-by: Martin Liu <liumartin@google.com>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Martin Liuauthored and Sorayukiicommited 2026-05-15 18:07:02 +07:00
When building lz4 under gcc-7 we get the following bogus warning:
CC [M] lib/lz4/lz4hc_compress.o
lib/lz4/lz4hc_compress.c: In function ‘lz4hc_compress’:
lib/lz4/lz4hc_compress.c:179:42: warning: ‘delta’ may be used uninitialized in this function [-Wmaybe-uninitialized]
chaintable[(size_t)(ptr) & MAXD_MASK] = delta;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
lib/lz4/lz4hc_compress.c:134:6: note: ‘delta’ was declared here
u16 delta;
^~~~~
This doesn't show up in the 4.4-stable tree due to us turning off
warnings like this. It also doesn't show up in newer kernel versions as
this code was totally rewritten.
So for now, to get the 4.9-stable tree to build with 0 warnings on x86
allmodconfig, let's just shut the compiler up by initializing the
variable to 0, despite it not really doing anything.
To be far, this code is crazy complex, so the fact that gcc can't
determine if the variable is really used or not isn't that bad, I'd
blame the code here instead of the compiler.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
These identifiers are bogus. The interested architectures should define
HAVE_EFFICIENT_UNALIGNED_ACCESS whenever relevant to do so. If this
isn't true for some arch, it should be fixed in the arch definition.
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rui Salvaterraauthored and Greg Kroah-Hartmancommited 2016-04-13 09:22:49 -07:00
Based on Sergey's test patch [1], this fixes zram with lz4 compression
on big endian cpus.
Note that the 64-bit preprocessor test is not a cleanup, it's part of
the fix, since those identifiers are bogus (for example, __ppc64__
isn't defined anywhere else in the kernel, which means we'd fall into
the 32-bit definitions on ppc64).
Tested on ppc64 with no regression on x86_64.
[1] http://marc.info/?l=linux-kernel&m=145994470805853&w=4
Cc: stable@vger.kernel.org
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rui Salvaterraauthored and Greg Kroah-Hartmancommited 2016-04-13 09:22:49 -07:00
Sometimes, on x86_64, decompression fails with the following
error:
Decompressing Linux...
Decoding failed
-- System halted
This condition is not needed for a 64bit kernel(from commit d5e7caf):
if( ... ||
(op + COPYLENGTH) > oend)
goto _output_error
macro LZ4_SECURE_COPY() tests op and does not copy any data
when op exceeds the value.
added by analogy to lz4_uncompress_unknownoutputsize(...)
Signed-off-by: Krzysztof Kolasa <kkolasa@winsoft.pl>
Tested-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Tested-by: Caleb Jorden <cjorden@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Krzysztof Kolasaauthored and Greg Kroah-Hartmancommited 2015-05-24 11:56:29 -07:00
There's no reason to allocate the dec{32,64}table on the stack; it
just wastes a bunch of instructions setting them up and, of course,
also consumes quite a bit of stack. Using size_t for such small
integers is a little excessive.
$ scripts/bloat-o-meter /tmp/built-in.o lib/built-in.o
add/remove: 2/2 grow/shrink: 2/0 up/down: 1304/-1548 (-244)
function old new delta
lz4_decompress_unknownoutputsize 55 718 +663
lz4_decompress 55 632 +577
dec64table - 32 +32
dec32table - 32 +32
lz4_uncompress 747 - -747
lz4_uncompress_unknownoutputsize 801 - -801
The now inlined lz4_uncompress functions used to have a stack
footprint of 176 bytes (according to -fstack-usage); their inlinees
have increased their stack use from 32 bytes to 48 and 80 bytes,
respectively.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Rasmus Villemoesauthored and Greg Kroah-Hartmancommited 2015-03-25 15:04:57 +01:00
If the part of the compression data are corrupted, or the compression
data is totally fake, the memory access over the limit is possible.
This is the log from my system usning lz4 decompression.
[6502]data abort, halting
[6503]r0 0x00000000 r1 0x00000000 r2 0xdcea0ffc r3 0xdcea0ffc
[6509]r4 0xb9ab0bfd r5 0xdcea0ffc r6 0xdcea0ff8 r7 0xdce80000
[6515]r8 0x00000000 r9 0x00000000 r10 0x00000000 r11 0xb9a98000
[6522]r12 0xdcea1000 usp 0x00000000 ulr 0x00000000 pc 0x820149bc
[6528]spsr 0x400001f3
and the memory addresses of some variables at the moment are
ref:0xdcea0ffc, op:0xdcea0ffc, oend:0xdcea1000
As you can see, COPYLENGH is 8bytes, so @ref and @op can access the momory
over @oend.
Signed-off-by: JeHyeon Yeon <tom.yeon@windriver.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
JeHyeon Yeonauthored and Greg Kroah-Hartmancommited 2015-03-16 21:55:35 +01:00
Jan points out that I forgot to make the needed fixes to the
lz4_uncompress_unknownoutputsize() function to mirror the changes done
in lz4_decompress() with regards to potential pointer overflows.
The only in-kernel user of this function is the zram code, which only
takes data from a valid compressed buffer that it made itself, so it's
not a big issue. But due to external kernel modules using this
function, it's better to be safe here.
Reported-by: Jan Beulich <JBeulich@suse.com>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is one other possible overrun in the lz4 code as implemented by
Linux at this point in time (which differs from the upstream lz4
codebase, but will get synced at in a future kernel release.) As
pointed out by Don, we also need to check the overflow in the data
itself.
While we are at it, replace the odd error return value with just a
"simple" -1 value as the return value is never used for anything other
than a basic "did this work or not" check.
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Reported-by: Willy Tarreau <w@1wt.eu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Given some pathologically compressed data, lz4 could possibly decide to
wrap a few internal variables, causing unknown things to happen. Catch
this before the wrapping happens and abort the decompression.
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LZ4 compression and decompression functions require different in
signedness input/output parameters: unsigned char for compression and
signed char for decompression.
Change decompression API to require "(const) unsigned char *".
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sergey Senozhatskyauthored and Linus Torvaldscommited 2013-09-11 15:59:45 -07:00
The LZ4 code is listed as using the "BSD 2-Clause License".
Signed-off-by: Richard Laager <rlaager@wiktel.com>
Acked-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Richard Yao <ryao@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ The 2-clause BSD can be just converted into GPL, but that's rude and
pointless, so don't do it - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Richard Laagerauthored and Linus Torvaldscommited 2013-08-23 09:51:22 -07:00
This patchset is for supporting LZ4 compression and the crypto API using
it.
As shown below, the size of data is a little bit bigger but compressing
speed is faster under the enabled unaligned memory access. We can use
lz4 de/compression through crypto API as well. Also, It will be useful
for another potential user of lz4 compression.
lz4 Compression Benchmark:
Compiler: ARM gcc 4.6.4
ARMv7, 1 GHz based board
Kernel: linux 3.4
Uncompressed data Size: 101 MB
Compressed Size compression Speed
LZO 72.1MB 32.1MB/s, 33.0MB/s(UA)
LZ4 75.1MB 30.4MB/s, 35.9MB/s(UA)
LZ4HC 59.8MB 2.4MB/s, 2.5MB/s(UA)
- UA: Unaligned memory Access support
- Latest patch set for LZO applied
This patch:
Add support for LZ4 compression in the Linux Kernel. LZ4 Compression APIs
for kernel are based on LZ4 implementation by Yann Collet and were changed
for kernel coding style.
LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository : http://code.google.com/p/lz4/
svn revision : r90
Two APIs are added:
lz4_compress() support basic lz4 compression whereas lz4hc_compress()
support high compression or CPU performance get lower but compression
ratio get higher. Also, we require the pre-allocated working memory with
the defined size and destination buffer must be allocated with the size of
lz4_compressbound.
[akpm@linux-foundation.org: make lz4_compresshcctx() static]
Signed-off-by: Chanho Min <chanho.min@lge.com>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chanho Minauthored and Linus Torvaldscommited 2013-07-09 10:33:30 -07:00
Add support for extracting LZ4-compressed kernel images, as well as
LZ4-compressed ramdisk images in the kernel boot process.
Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kyungsik Leeauthored and Linus Torvaldscommited 2013-07-09 10:33:30 -07:00
Add support for LZ4 decompression in the Linux Kernel. LZ4 Decompression
APIs for kernel are based on LZ4 implementation by Yann Collet.
Benchmark Results(PATCH v3)
Compiler: Linaro ARM gcc 4.6.2
1. ARMv7, 1.5GHz based board
Kernel: linux 3.4
Uncompressed Kernel Size: 14MB
Compressed Size Decompression Speed
LZO 6.7MB 20.1MB/s, 25.2MB/s(UA)
LZ4 7.3MB 29.1MB/s, 45.6MB/s(UA)
2. ARMv7, 1.7GHz based board
Kernel: linux 3.7
Uncompressed Kernel Size: 14MB
Compressed Size Decompression Speed
LZO 6.0MB 34.1MB/s, 52.2MB/s(UA)
LZ4 6.5MB 86.7MB/s
- UA: Unaligned memory Access support
- Latest patch set for LZO applied
This patch set is for adding support for LZ4-compressed Kernel. LZ4 is a
very fast lossless compression algorithm and it also features an extremely
fast decoder [1].
But we have five of decompressors already and one question which does
arise, however, is that of where do we stop adding new ones? This issue
had been discussed and came to the conclusion [2].
Russell King said that we should have:
- one decompressor which is the fastest
- one decompressor for the highest compression ratio
- one popular decompressor (eg conventional gzip)
If we have a replacement one for one of these, then it should do exactly
that: replace it.
The benchmark shows that an 8% increase in image size vs a 66% increase
in decompression speed compared to LZO(which has been known as the
fastest decompressor in the Kernel). Therefore the "fast but may not be
small" compression title has clearly been taken by LZ4 [3].
[1] http://code.google.com/p/lz4/
[2] http://thread.gmane.org/gmane.linux.kbuild.devel/9157
[3] http://thread.gmane.org/gmane.linux.kbuild.devel/9347
LZ4 homepage: http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository: http://code.google.com/p/lz4/
Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Yann Collet <yann.collet.73@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kyungsik Leeauthored and Linus Torvaldscommited 2013-07-09 10:33:30 -07:00
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authored and
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authored and
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authored and
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