kernel/lib/lz4, branch linux-4.3.y

lz4: fix system halt at boot kernel on x86_64

2015-05-24T18:56:29Z

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 Tested-by: Alexander Kuleshov Tested-by: Caleb Jorden Signed-off-by: Greg Kroah-Hartman

lib/lz4: Pull out constant tables

2015-03-25T14:04:57Z

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 Signed-off-by: Greg Kroah-Hartman

LZ4 : fix the data abort issue

2015-03-16T20:55:35Z

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 Reviewed-by: David Sterba Signed-off-by: Greg Kroah-Hartman

lz4: add overrun checks to lz4_uncompress_unknownoutputsize()

2014-07-03T23:12:04Z

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 Cc: "Don A. Bailey" Cc: stable Signed-off-by: Greg Kroah-Hartman

lz4: fix another possible overrun

2014-06-27T18:21:07Z

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" Reported-by: Willy Tarreau Cc: stable Signed-off-by: Greg Kroah-Hartman

lz4: ensure length does not wrap

2014-06-23T18:12:01Z

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" Cc: stable Signed-off-by: Greg Kroah-Hartman

lz4: fix compression/decompression signedness mismatch

2013-09-11T22:59:45Z

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 Cc: Kyungsik Lee Cc: Geert Uytterhoeven Cc: Yann Collet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/lz4: correct the LZ4 license

2013-08-23T16:51:22Z

The LZ4 code is listed as using the "BSD 2-Clause License". Signed-off-by: Richard Laager Acked-by: Kyungsik Lee Cc: Chanho Min Cc: Richard Yao Signed-off-by: Andrew Morton [ 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

lib: add lz4 compressor module

2013-07-09T17:33:30Z

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 Cc: "Darrick J. Wong" Cc: Bob Pearson Cc: Richard Weinberger Cc: Herbert Xu Cc: Yann Collet Cc: Kyungsik Lee Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: add support for LZ4-compressed kernel

2013-07-09T17:33:30Z

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 Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Russell King Cc: Borislav Petkov Cc: Florian Fainelli Cc: Yann Collet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds