linux-stable.git/lib/lzo, branch linux-2.6.32.y

lzo: check for length overrun in variable length encoding.

2014-11-23T09:55:52+00:00

This fix ensures that we never meet an integer overflow while adding
255 while parsing a variable length encoding. It works differently from
commit 206a81c ("lzo: properly check for overruns") because instead of
ensuring that we don't overrun the input, which is tricky to guarantee
due to many assumptions in the code, it simply checks that the cumulated
number of 255 read cannot overflow by bounding this number.

The MAX_255_COUNT is the maximum number of times we can add 255 to a base
count without overflowing an integer. The multiply will overflow when
multiplying 255 by more than MAXINT/255. The sum will overflow earlier
depending on the base count. Since the base count is taken from a u8
and a few bits, it is safe to assume that it will always be lower than
or equal to 2*255, thus we can always prevent any overflow by accepting
two less 255 steps.

This patch also reduces the CPU overhead and actually increases performance
by 1.1% compared to the initial code, while the previous fix costs 3.1%
(measured on x86_64).

The fix needs to be backported to all currently supported stable kernels.

Reported-by: Willem Pinckaers 
Cc: "Don A. Bailey" 
Cc: stable 
Signed-off-by: Willy Tarreau 
Signed-off-by: Greg Kroah-Hartman 
(cherry picked from commit 72cf90124e87d975d0b2114d930808c58b4c05e4)
Signed-off-by: Willy Tarreau

lib/lzo: Update LZO compression to current upstream version

2014-11-23T09:55:51+00:00

This commit updates the kernel LZO code to the current upsteam version
which features a significant speed improvement - benchmarking the Calgary
and Silesia test corpora typically shows a doubled performance in
both compression and decompression on modern i386/x86_64/powerpc machines.

Signed-off-by: Markus F.X.J. Oberhumer 
(cherry picked from commit 8b975bd3f9089f8ee5d7bbfd798537b992bbc7e7)
[wt: this update was only needed to apply the following security fixes]
Signed-off-by: Willy Tarreau

lzo: use get/put_unaligned_* helpers

2008-07-25T17:53:26+00:00

Signed-off-by: Harvey Harrison 
Acked-by: Richard Purdie 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lzo: fix typo in decompressor

2008-04-10T22:34:05+00:00

Shift of a LE value seems strange, probably meant to shift the cpu-order
variable as in the prvious section of the switch statement.

Signed-off-by: Harvey Harrison 
Acked-by: Richard Purdie 
Signed-off-by: Linus Torvalds

lzo: add some missing casts

2007-07-31T22:39:37+00:00

Add some casts to the LZO compression algorithm after they were removed
during cleanup and shouldn't have been.

Signed-off-by: Richard Purdie 
Cc: Edward Shishkin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Add LZO1X algorithm to the kernel

2007-07-11T00:51:13+00:00

This is a hybrid version of the patch to add the LZO1X compression
algorithm to the kernel.  Nitin and myself have merged the best parts of
the various patches to form this version which we're both happy with (and
are jointly signing off).

The performance of this version is equivalent to the original minilzo code
it was based on.  Bytecode comparisons have also been made on ARM, i386 and
x86_64 with favourable results.

There are several users of LZO lined up including jffs2, crypto and reiser4
since its much faster than zlib.

Signed-off-by: Nitin Gupta 
Signed-off-by: Richard Purdie 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds