Commit Graph

568 Commits

Author SHA1 Message Date
Lasse Collin 06824396b2 Build: Don't put GNU/Linux-specific symbol versions into static liblzma.
It not only makes no sense to put symbol versions into a static library
but it can also cause breakage.

By default Libtool #defines PIC if building a shared library and
doesn't define it for static libraries. This is documented in the
Libtool manual. It can be overriden using --with-pic or --without-pic.
configure.ac detects if --with-pic or --without-pic is used and then
gives an error if neither --disable-shared nor --disable-static was
used at the same time. Thus, in normal situations it works to build
both shared and static library at the same time on GNU/Linux,
only --with-pic or --without-pic requires that only one type of
library is built.

Thanks to John Paul Adrian Glaubitz from Debian for reporting
the problem that occurred on ia64:
https://www.mail-archive.com/xz-devel@tukaani.org/msg00610.html
2022-11-24 14:52:44 +02:00
Lasse Collin e1acf71072 liblzma: Refactor to use lzma_filters_free().
lzma_filters_free() sets the options to NULL and ids to
LZMA_VLI_UNKNOWN so there is no need to do it by caller;
the filter arrays will always be left in a safe state.

Also use memcpy() instead of a loop to copy a filter chain
when it is known to be safe to copy LZMA_FILTERS_MAX + 1
(even if the elements past the terminator might be uninitialized).
2022-11-24 01:32:16 +02:00
Lasse Collin cb05dbcf8b liblzma: Fix another invalid free() after memory allocation failure.
This time it can happen when lzma_stream_encoder_mt() is used
to reinitialize an existing multi-threaded Stream encoder
and one of 1-4 tiny allocations in lzma_filters_copy() fail.

It's very similar to the previous bug
10430fbf38, happening with
an array of lzma_filter structures whose old options are freed
but the replacement never arrives due to a memory allocation
failure in lzma_filters_copy().
2022-11-24 01:26:37 +02:00
Jia Tan 75f1a6c26d liblzma: Add support for LZMA_SYNC_FLUSH in the Block encoder.
The documentation mentions that lzma_block_encoder() supports
LZMA_SYNC_FLUSH but it was never added to supported_actions[]
in the internal structure. Because of this, LZMA_SYNC_FLUSH could
not be used with the Block encoder unless it was the next coder
after something like stream_encoder() or stream_encoder_mt().
2022-11-24 01:07:32 +02:00
Lasse Collin d090164517 liblzma: Add new API function lzma_filters_free().
This is small but convenient and should have been added
a long time ago.
2022-11-24 01:02:50 +02:00
Lasse Collin 48c1b99dc5 liblzma: Add lzma_attr_warn_unused_result to lzma_filters_copy(). 2022-11-23 21:55:22 +02:00
Lasse Collin 10430fbf38 liblzma: Fix invalid free() after memory allocation failure.
The bug was in the single-threaded .xz Stream encoder
in the code that is used for both re-initialization and for
lzma_filters_update(). To trigger it, an application had
to either re-initialize an existing encoder instance with
lzma_stream_encoder() or use lzma_filters_update(), and
then one of the 1-4 tiny allocations in lzma_filters_copy()
(called from stream_encoder_update()) must fail. An error
was correctly reported but the encoder state was corrupted.

This is related to the recent fix in
f8ee61e74e which is good but
it wasn't enough to fix the main problem in stream_encoder.c.
2022-11-23 21:26:21 +02:00
Lasse Collin cafd6dc397 liblzma: Fix language in a comment. 2022-11-22 16:37:15 +02:00
Lasse Collin c392bf8ccb liblzma: Fix infinite loop in LZMA encoder init with dict_size >= 2 GiB.
The encoder doesn't support dictionary sizes larger than 1536 MiB.
This is validated, for example, when calculating the memory usage
via lzma_raw_encoder_memusage(). It is also enforced by the LZ
part of the encoder initialization. However, LZMA encoder with
LZMA_MODE_NORMAL did an unsafe calculation with dict_size before
such validation and that results in an infinite loop if dict_size
was 2 << 30 or greater.
2022-11-22 11:23:23 +02:00
Lasse Collin f50534c973 liblzma: Fix two Doxygen commands in the API headers.
These were caught by clang -Wdocumentation.
2022-11-21 13:02:33 +02:00
Lasse Collin b9a67d9a5f Bump version number for 5.3.4alpha. 2022-11-15 11:18:28 +02:00
Lasse Collin b56bc8251d Revert "liblzma: Simple/BCJ filters: Allow disabling generic BCJ options."
This reverts commit 177bdc922c
and also does equivalent change to arm64.c.

Now that ARM64 filter will use lzma_options_bcj, this change
is not needed anymore.
2022-11-14 23:19:57 +02:00
Lasse Collin 8370ec8edf Replace the experimental ARM64 filter with a new experimental version.
This is incompatible with the previous version.

This has space/tab fixes in filter_*.c and bcj.h too.
2022-11-14 23:16:38 +02:00
Lasse Collin f644473a21 liblzma: Add fast CRC64 for 32/64-bit x86 using SSSE3 + SSE4.1 + CLMUL.
It also works on E2K as it supports these intrinsics.

On x86-64 runtime detection is used so the code keeps working on
older processors too. A CLMUL-only build can be done by using
-msse4.1 -mpclmul in CFLAGS and this will reduce the library
size since the generic implementation and its 8 KiB lookup table
will be omitted.

On 32-bit x86 this isn't used by default for now because by default
on 32-bit x86 the separate assembly file crc64_x86.S is used.
If --disable-assembler is used then this new CLMUL code is used
the same way as on 64-bit x86. However, a CLMUL-only build
(-msse4.1 -mpclmul) won't omit the 8 KiB lookup table on
32-bit x86 due to a currently-missing check for disabled
assembler usage.

The configure.ac check should be such that the code won't be
built if something in the toolchain doesn't support it but
--disable-clmul-crc option can be used to unconditionally
disable this feature.

CLMUL speeds up decompression of files that have compressed very
well (assuming CRC64 is used as a check type). It is know that
the CLMUL code is significantly slower than the generic code for
tiny inputs (especially 1-8 bytes but up to 16 bytes). If that
is a real-world problem then there is already a commented-out
variant that uses the generic version for small inputs.

Thanks to Ilya Kurdyukov for the original patch which was
derived from a white paper from Intel [1] (published in 2009)
and public domain code from [2] (released in 2016).

[1] https://www.intel.com/content/dam/www/public/us/en/documents/white-papers/fast-crc-computation-generic-polynomials-pclmulqdq-paper.pdf
[2] https://github.com/rawrunprotected/crc
2022-11-14 23:05:46 +02:00
Lasse Collin eb0f1450ad liblzma: Use __attribute__((__constructor__)) if available.
This uses it for CRC table initializations when using --disable-small.
It avoids mythread_once() overhead. It also means that then
--disable-small --disable-threads is thread-safe if this attribute
is supported.
2022-11-14 16:00:52 +02:00
Lasse Collin a39961ef21 liblzma: Fix building with Intel ICC (the classic compiler).
It claims __GNUC__ >= 10 but doesn't support __symver__ attribute.

Thanks to Stephen Sachs.
2022-11-11 17:15:25 +02:00
Lasse Collin c715f683dc liblzma: Fix incorrect #ifdef for x86 SSE2 support.
__SSE2__ is the correct macro for SSE2 support with GCC, Clang,
and ICC. __SSE2_MATH__ means doing floating point math with SSE2
instead of 387. Often the latter macro is defined if the first
one is but it was still a bug.
2022-11-11 14:35:58 +02:00
Lasse Collin 034086e1ae liblzma: Add .lz support to lzma_auto_decoder().
Thanks to Michał Górny for the original patch.
2022-11-09 14:25:26 +02:00
Lasse Collin 0538db038f liblzma: Add .lz (lzip) decompression support (format versions 0 and 1).
Support for format version 0 was removed from lzip 1.18 for some
reason. .lz format version 0 files are rare (and old) but some
source packages were released in this format, and some people might
have personal files in this format too. It's very little extra code
to support it along side format version 1 so this commits adds
support for both.

The Sync Flush marker extentension to the original .lz format
version 1 isn't supported. It would require changes to the
LZMA decoder itself. Such files are very rare anyway.

See the API doc for lzma_lzip_decoder() for more details about
the .lz format support.

Thanks to Michał Górny for the original patch.
2022-11-09 14:24:20 +02:00
Lasse Collin 633d48a075 liblzma: Add the missing Makefile.inc change for --disable-microlzma.
This was forgotten from commit 59c4d6e139.
2022-11-09 14:17:23 +02:00
Lasse Collin 4746f5ec72 liblzma: Update API docs about decoder flags. 2022-11-08 14:13:03 +02:00
Lasse Collin 8779a9db5d liblzma: Use the return_if_error() macro in alone_decoder.c. 2022-11-08 14:01:50 +02:00
Lasse Collin 3f4990b682 liblzma: Fix a comment in auto_decoder.c. 2022-11-08 14:00:58 +02:00
Lasse Collin 5e2450c75c liblzma: Include cached memory in reported memusage in threaded decoder.
This affects lzma_memusage() and lzma_memlimit_set() when used
with the threaded decompressor. Now all allocations are reported
by lzma_memusage() (so it's not misleading) and lzma_memlimit_set()
cannot lower the limit below that value.

The alternative would have been to allow lowering the limit if
doing so is possible by freeing the cached memory but since
the primary use case of lzma_memlimit_set() is to increase
memlimit after LZMA_MEMLIMIT_ERROR this simple approach
was selected.

The cached memory was always included when enforcing
the memory usage limit while decoding.

Thanks to Jia Tan.
2022-11-07 17:22:04 +02:00
Lasse Collin 48dde3bab9 liblzma: Silence -Wconversion warning from crc64_fast.c. 2022-10-31 11:54:44 +02:00
Lasse Collin fda9f85f52 liblzma: Threaded decoder: Stop the worker threads on errors.
It's waste of CPU time and electricity to leave the unfinished
worker threads running when it is known that their output will
get ignored.
2022-10-24 16:25:09 +03:00
Jia Tan 14af758a77 liblzma: Fix a compilation issue when encoders are disabled.
When encoders were disabled and threading enabled, outqueue.c and
outqueue.h were not compiled. The multi threaded decoder required
these files, so compilation failed.
2022-10-05 16:11:33 +03:00
Lasse Collin fae37ad2af tuklib_integer: Add 64-bit endianness-converting reads and writes.
Also update the comment in liblzma's memcmplen.h.

Thanks to Michał Górny for the original patch for the reads.
2022-10-05 14:26:00 +03:00
Lasse Collin 508a44372c liblzma: Add API doc note about the .xz decoder LZMA_MEMLIMIT_ERROR bug.
The bug was fixed in 660739f99a.
2022-09-30 12:06:13 +03:00
Jia Tan 8cc9874a79 liblzma: Add dest and src NULL checks to lzma_index_cat.
The documentation states LZMA_PROG_ERROR can be returned from
lzma_index_cat. Previously, lzma_index_cat could not return
LZMA_PROG_ERROR. Now, the validation is similar to
lzma_index_append, which does a NULL check on the index
parameter.
2022-09-28 15:48:03 +03:00
Jia Tan 3d5a99ca37 liblzma: Fix copying of check type statistics in lzma_index_cat().
The check type of the last Stream in dest was never copied to
dest->checks (the code tried to copy it but it was done too late).
This meant that the value returned by lzma_index_checks() would
only include the check type of the last Stream when multiple
lzma_indexes had been concatenated.

In xz --list this meant that the summary would only list the
check type of the last Stream, so in this sense this was only
a visual bug. However, it's possible that some applications
use this information for purposes other than merely showing
it to the users in an informational message. I'm not aware of
such applications though and it's quite possible that such
applications don't exist.

Regular streamed decompression in xz or any other application
doesn't use lzma_index_cat() and so this bug cannot affect them.
2022-09-28 15:29:49 +03:00
Lasse Collin 660739f99a liblzma: Stream decoder: Fix restarting after LZMA_MEMLIMIT_ERROR.
If lzma_code() returns LZMA_MEMLIMIT_ERROR it is now possible
to use lzma_memlimit_set() to increase the limit and continue
decoding. This was supposed to work from the beginning but
there was a bug. With other decoders (.lzma or threaded .xz)
this already worked correctly.
2022-09-28 11:05:15 +03:00
Lasse Collin 7e68fda58c liblzma: Stream decoder: Fix comments. 2022-09-28 11:00:23 +03:00
Lasse Collin f664cb2584 liblzma: ARM64: Add comments. 2022-09-20 16:58:22 +03:00
Lasse Collin b557b4a0ee liblzma: ARM64: Fix wrong comment in API doc.
Thanks to Jia Tan.
2022-09-20 16:27:50 +03:00
Lasse Collin ecb966de30 liblzma: Add experimental ARM64 BCJ filter with a temporary Filter ID.
That is, the Filter ID will be changed once the design is final.
The current version will be removed. So files created with the
tempoary Filter ID won't be supported in the future.
2022-09-19 20:23:46 +03:00
Lasse Collin 177bdc922c liblzma: Simple/BCJ filters: Allow disabling generic BCJ options.
This will be needed for the ARM64 BCJ filter as it will use
its own options struct.
2022-09-17 22:42:18 +03:00
Lasse Collin f8ee61e74e liblzma: lzma_filters_copy: Keep dest[] unmodified if an error occurs.
lzma_stream_encoder() and lzma_stream_encoder_mt() always assumed
this. Before this patch, failing lzma_filters_copy() could result
in free(invalid_pointer) or invalid memory reads in stream_encoder.c
or stream_encoder_mt.c.

To trigger this, allocating memory for a filter options structure
has to fail. These are tiny allocations so in practice they very
rarely fail.

Certain badness in the filter chain array could also make
lzma_filters_copy() fail but both stream_encoder.c and
stream_encoder_mt.c validate the filter chain before
trying to copy it, so the crash cannot occur this way.
2022-09-09 13:51:57 +03:00
Jia Tan 18d7facd38 liblzma: lzma_index_append: Add missing integer overflow check.
The documentation in src/liblzma/api/lzma/index.h suggests that
both the unpadded (compressed) size and the uncompressed size
are checked for overflow, but only the unpadded size was checked.
The uncompressed check is done first since that is more likely to
occur than the unpadded or index field size overflows.
2022-09-08 15:19:19 +03:00
Lasse Collin 913ddc5572 liblzma: Vaccinate against an ill patch from RHEL/CentOS 7.
RHEL/CentOS 7 shipped with 5.1.2alpha, including the threaded
encoder that is behind #ifdef LZMA_UNSTABLE in the API headers.
In 5.1.2alpha these symbols are under XZ_5.1.2alpha in liblzma.map.
API/ABI compatibility tracking isn't done between development
releases so newer releases didn't have XZ_5.1.2alpha anymore.

Later RHEL/CentOS 7 updated xz to 5.2.2 but they wanted to keep
the exported symbols compatible with 5.1.2alpha. After checking
the ABI changes it turned out that >= 5.2.0 ABI is backward
compatible with the threaded encoder functions from 5.1.2alpha
(but not vice versa as fixes and extensions to these functions
were made between 5.1.2alpha and 5.2.0).

In RHEL/CentOS 7, XZ Utils 5.2.2 was patched with
xz-5.2.2-compat-libs.patch to modify liblzma.map:

  - XZ_5.1.2alpha was added with lzma_stream_encoder_mt and
    lzma_stream_encoder_mt_memusage. This matched XZ Utils 5.1.2alpha.

  - XZ_5.2 was replaced with XZ_5.2.2. It is clear that this was
    an error; the intention was to keep using XZ_5.2 (XZ_5.2.2
    has never been used in XZ Utils). So XZ_5.2.2 lists all
    symbols that were listed under XZ_5.2 before the patch.
    lzma_stream_encoder_mt and _mt_memusage are included too so
    they are listed both here and under XZ_5.1.2alpha.

The patch didn't add any __asm__(".symver ...") lines to the .c
files. Thus the resulting liblzma.so exports the threaded encoder
functions under XZ_5.1.2alpha only. Listing the two functions
also under XZ_5.2.2 in liblzma.map has no effect without
matching .symver lines.

The lack of XZ_5.2 in RHEL/CentOS 7 means that binaries linked
against unpatched XZ Utils 5.2.x won't run on RHEL/CentOS 7.
This is unfortunate but this alone isn't too bad as the problem
is contained within RHEL/CentOS 7 and doesn't affect users
of other distributions. It could also be fixed internally in
RHEL/CentOS 7.

The second problem is more serious: In XZ Utils 5.2.2 the API
headers don't have #ifdef LZMA_UNSTABLE for obvious reasons.
This is true in RHEL/CentOS 7 version too. Thus now programs
using new APIs can be compiled without an extra #define. However,
the programs end up depending on symbol version XZ_5.1.2alpha
(and possibly also XZ_5.2.2) instead of XZ_5.2 as they would
with an unpatched XZ Utils 5.2.2. This means that such binaries
won't run on other distributions shipping XZ Utils >= 5.2.0 as
they don't provide XZ_5.1.2alpha or XZ_5.2.2; they only provide
XZ_5.2 (and XZ_5.0). (This includes RHEL/CentOS 8 as the patch
luckily isn't included there anymore with XZ Utils 5.2.4.)

Binaries built by RHEL/CentOS 7 users get distributed and then
people wonder why they don't run on some other distribution.
Seems that people have found out about the patch and been copying
it to some build scripts, seemingly curing the symptoms but
actually spreading the illness further and outside RHEL/CentOS 7.

The ill patch seems to be from late 2016 (RHEL 7.3) and in 2017 it
had spread at least to EasyBuild. I heard about the events only
recently. :-(

This commit splits liblzma.map into two versions: one for
GNU/Linux and another for other OSes that can use symbol versioning
(FreeBSD, Solaris, maybe others). The Linux-specific file and the
matching additions to .c files add full compatibility with binaries
that have been built against a RHEL/CentOS-patched liblzma. Builds
for OSes other than GNU/Linux won't get the vaccine as they should
be immune to the problem (I really hope that no build script uses
the RHEL/CentOS 7 patch outside GNU/Linux).

The RHEL/CentOS compatibility symbols XZ_5.1.2alpha and XZ_5.2.2
are intentionally put *after* XZ_5.2 in liblzma_linux.map. This way
if one forgets to #define HAVE_SYMBOL_VERSIONS_LINUX when building,
the resulting liblzma.so.5 will have lzma_stream_encoder_mt@@XZ_5.2
since XZ_5.2 {...} is the first one that lists that function.
Without HAVE_SYMBOL_VERSIONS_LINUX @XZ_5.1.2alpha and @XZ_5.2.2
will be missing but that's still a minor problem compared to
only having lzma_stream_encoder_mt@@XZ_5.1.2alpha!

The "local: *;" line was moved to XZ_5.0 so that it doesn't need
to be moved around. It doesn't matter where it is put.

Having two similar liblzma_*.map files is a bit silly as it is,
at least for now, easily possible to generate the generic one
from the Linux-specific file. But that adds extra steps and
increases the risk of mistakes when supporting more than one
build system. So I rather maintain two files in parallel and let
validate_map.sh check that they are in sync when "make mydist"
is run.

This adds .symver lines for lzma_stream_encoder_mt@XZ_5.2.2 and
lzma_stream_encoder_mt_memusage@XZ_5.2.2 even though these
weren't exported by RHEL/CentOS 7 (only @@XZ_5.1.2alpha was
for these two). I added these anyway because someone might
misunderstand the RHEL/CentOS 7 patch and think that @XZ_5.2.2
(@@XZ_5.2.2) versions were exported too.

At glance one could suggest using __typeof__ to copy the function
prototypes when making aliases. However, this doesn't work trivially
because __typeof__ won't copy attributes (lzma_nothrow, lzma_pure)
and it won't change symbol visibility from hidden to default (done
by LZMA_API()). Attributes could be copied with __copy__ attribute
but that needs GCC 9 and a fallback method would be needed anyway.

This uses __symver__ attribute with GCC >= 10 and
__asm__(".symver ...") with everything else. The attribute method
is required for LTO (-flto) support with GCC. Using -flto with
GCC older than 10 is now broken on GNU/Linux and will not be fixed
(can silently result in a broken liblzma build that has dangerously
incorrect symbol versions). LTO builds with Clang seem to work
with the traditional __asm__(".symver ...") method.

Thanks to Boud Roukema for reporting the problem and discussing
the details and testing the fix.
2022-09-08 15:01:29 +03:00
Lasse Collin c1555b1a22 Bump version number for 5.3.3alpha. 2022-08-22 18:16:40 +03:00
Lasse Collin c4e8e5fb31 liblzma: Threaded decoder: Improve LZMA_FAIL_FAST when LZMA_FINISH is used.
It will now return LZMA_DATA_ERROR (not LZMA_OK or LZMA_BUF_ERROR)
if LZMA_FINISH is used and there isn't enough input to finish
decoding the Block Header or the Block. The use of LZMA_DATA_ERROR
is simpler and the less risky than LZMA_BUF_ERROR but this might
be changed before 5.4.0.
2022-08-18 17:16:49 +03:00
Jia Tan 61f8ec804a liblzma: Refactor lzma_mf_is_supported() to use a switch-statement. 2022-07-25 18:30:10 +03:00
Lasse Collin 107c93ee5c liblzma: Rename a variable and improve a comment. 2022-07-14 18:12:38 +03:00
Lasse Collin 9595a3119b liblzma: Add optional autodetection of LZMA end marker.
Turns out that this is needed for .lzma files as the spec in
LZMA SDK says that end marker may be present even if the size
is stored in the header. Such files are rare but exist in the
real world. The code in liblzma is so old that the spec didn't
exist in LZMA SDK back then and I had understood that such
files weren't possible (the lzma tool in LZMA SDK didn't
create such files).

This modifies the internal API so that LZMA decoder can be told
if EOPM is allowed even when the uncompressed size is known.
It's allowed with .lzma and not with other uses.

Thanks to Karl Beldan for reporting the problem.
2022-07-13 22:24:07 +03:00
Lasse Collin 2ce4f36f17 liblzma: Silence a warning.
The actual initialization is done via mythread_sync and seems
that GCC doesn't necessarily see that it gets initialized there.
2022-05-23 19:37:18 +03:00
Lasse Collin fe87b4cd53 liblzma: Threaded decoder: Improve setting of pending_error.
It doesn't need to be done conditionally. The comments try
to explain it.
2022-04-06 23:11:59 +03:00
Lasse Collin 90621da7f6 liblzma: Add a new flag LZMA_FAIL_FAST for threaded decoder.
In most cases if the input file is corrupt the application won't
care about the uncompressed content at all. With this new flag
the threaded decoder will return an error as soon as any thread
has detected an error; it won't wait to copy out the data before
the location of the error.

I don't plan to use this in xz to keep the behavior consistent
between single-threaded and multi-threaded modes.
2022-04-06 13:16:00 +03:00
Lasse Collin 64b6d496dc liblzma: Threaded decoder: Always wait for output if LZMA_FINISH is used.
This makes the behavior consistent with the single-threaded
decoder when handling truncated .xz files.

Thanks to Jia Tan for finding this issue.
2022-04-05 12:24:57 +03:00
Lasse Collin e671bc8828 liblzma: Threaded decoder: Support zpipe.c-style decoding loop.
This makes it possible to call lzma_code() in a loop that only
reads new input when lzma_code() didn't fill the output buffer
completely. That isn't the calling style suggested by the
liblzma example program 02_decompress.c so perhaps the usefulness
of this feature is limited.

Also, it is possible to write such a loop so that it works
with the single-threaded decoder but not with the threaded
decoder even after this commit, or so that it works only if
lzma_mt.timeout = 0.

The zlib tutorial <https://zlib.net/zlib_how.html> is a well-known
example of a loop where more input is read only when output isn't
full. Porting this as is to liblzma would work with the
single-threaded decoder (if LZMA_CONCATENATED isn't used) but it
wouldn't work with threaded decoder even after this commit because
the loop assumes that no more output is possible when it cannot
read more input ("if (strm.avail_in == 0) break;"). This cannot
be fixed at liblzma side; the loop has to be modified at least
a little.

I'm adding this in any case because the actual code is simple
and short and should have no harmful side-effects in other
situations.
2022-04-02 21:49:59 +03:00
Lasse Collin bd93b776c1 liblzma: Fix a deadlock in threaded decoder.
If a worker thread has consumed all input so far and it's
waiting on thr->cond and then the main thread enables
partial update for that thread, the code used to deadlock.
This commit allows one dummy decoding pass to occur in this
situation which then also does the partial update.

As part of the fix, this moves thr->progress_* updates to
avoid the second thr->mutex locking.

Thanks to Jia Tan for finding, debugging, and reporting the bug.
2022-03-26 01:15:32 +02:00
Lasse Collin 487c77d487 liblzma: Threaded decoder: Don't stop threads on LZMA_TIMED_OUT.
LZMA_TIMED_OUT is not an error and thus stopping threads on
LZMA_TIMED_OUT breaks the decoder badly.

Thanks to Jia Tan for finding the bug and for the patch.
2022-03-23 16:28:55 +02:00
Lasse Collin 4cce3e27f5 liblzma: Add threaded .xz decompressor.
I realize that this is about a decade late.

Big thanks to Sebastian Andrzej Siewior for the original patch.
I made a bunch of smaller changes but after a while quite a few
things got rewritten. So any bugs in the commit were created by me.
2022-03-07 00:35:53 +02:00
Lasse Collin 717631b978 liblzma: Fix docs: lzma_block_decoder() cannot return LZMA_UNSUPPORTED_CHECK.
If Check is unsupported, it will be silently ignored.
It's the caller's job to handle it.
2022-03-06 16:54:23 +02:00
Lasse Collin 1a4bb97a00 liblzma: Add new output queue (lzma_outq) features.
Add lzma_outq_clear_cache2() which may leave one buffer allocated
in the cache.

Add lzma_outq_outbuf_memusage() to get the memory needed for
a single lzma_outbuf. This is now used internally in outqueue.c too.

Track both the total amount of memory allocated and the amount of
memory that is in active use (not in cache).

In lzma_outbuf, allow storing the current input position that
matches the current output position. This way the main thread
can notice when no more output is possible without first providing
more input.

Allow specifying return code for lzma_outq_read() in a finished
lzma_outbuf.
2022-03-06 16:41:19 +02:00
Lasse Collin ddbc6f58c2 liblzma: Index hash: Change return value type of hash_append() to void. 2022-03-06 15:18:58 +02:00
Lasse Collin 20e7a33e2d liblzma: Minor addition to lzma_vli_size() API doc.
Thanks to Jia Tan.
2022-02-22 03:42:57 +02:00
Lasse Collin 4f78f5fcf6 liblzma: Check the return value of lzma_index_append() in threaded encoder.
If lzma_index_append() failed (most likely memory allocation failure)
it could have gone unnoticed and the resulting .xz file would have
an incorrect Index. Decompressing such a file would produce the
correct uncompressed data but then an error would occur when
verifying the Index field.
2022-02-22 02:04:18 +02:00
Ed Maste 865e0a3689 liblzma: Use non-executable stack on FreeBSD as on Linux 2022-02-22 01:23:34 +02:00
Lasse Collin 1c9a5786d2 liblzma: Make Block decoder catch certain types of errors better.
Now it limits the input and output buffer sizes that are
passed to a raw decoder. This way there's no need to check
if the sizes can grow too big or overflow when updating
Compressed Size and Uncompressed Size counts. This also means
that a corrupt file cannot cause the raw decoder to process
useless extra input or output that would exceed the size info
in Block Header (and thus cause LZMA_DATA_ERROR anyway).

More importantly, now the size information is verified more
carefully in case raw decoder returns LZMA_OK. This doesn't
really matter with the current single-threaded .xz decoder
as the errors would be detected slightly later anyway. But
this helps avoiding corner cases in the upcoming threaded
decompressor, and it might help other Block decoder uses
outside liblzma too.

The test files bad-1-lzma2-{9,10,11}.xz test these conditions.
With the single-threaded .xz decoder the only difference is
that LZMA_DATA_ERROR is detected in a difference place now.
2022-02-20 20:36:27 +02:00
jiat75 6468f7e41a liblzma: Add NULL checks to LZMA and LZMA2 properties encoders.
Previously lzma_lzma_props_encode() and lzma_lzma2_props_encode()
assumed that the options pointers must be non-NULL because the
with these filters the API says it must never be NULL. It is
good to do these checks anyway.
2022-02-07 00:20:01 +02:00
Lasse Collin 2523c30705 liblzma: Fix uint64_t vs. size_t confusion.
This broke 32-bit builds due to a pointer type mismatch.

This bug was introduced with the output-size-limited encoding
in 625f4c7c99.

Thanks to huangqinjin for the bug report.
2022-02-06 23:19:32 +02:00
Lasse Collin edf525e2b1 Bump the version number for 5.3.2alpha. 2021-10-28 23:02:11 +03:00
Lasse Collin 2b509c868c liblzma: Fix liblzma.map for the lzma_microlzma_* symbols.
This should have been part of d267d109c3.

Thanks to Gao Xiang.
2021-09-17 17:31:11 +03:00
Lasse Collin 6928aac9da liblzma: Use _MSVC_LANG to detect when "noexcept" can be used with MSVC.
By default, MSVC always sets __cplusplus to 199711L. The real
C++ standard version is available in _MSVC_LANG (or one could
use /Zc:__cplusplus to set __cplusplus correctly).

Fixes <https://sourceforge.net/p/lzmautils/discussion/708858/thread/f6bc3b108a/>.

Thanks to Dan Weiss.
2021-09-09 21:41:51 +03:00
Lasse Collin d267d109c3 liblzma: Rename EROFS LZMA to MicroLZMA.
It still exists primarily for EROFS but MicroLZMA is
a more generic name (that hopefully doesn't clash with
something that already exists).
2021-09-05 20:38:12 +03:00
Lasse Collin 6c6f0db340 liblzma: Fix unitialized variable.
This was introduced two weeks ago in the commit
625f4c7c99.

Thanks to Nathan Moinvaziri.
2021-01-29 21:19:08 +02:00
Lasse Collin 6b8abc84a5 liblzma: Fix a wrong comment in stream_encoder_mt.c. 2021-01-24 19:22:35 +02:00
Lasse Collin db465419ae liblzma: In EROFS LZMA decoder, verify that comp_size matches at the end.
When the uncompressed size is known to be exact, after decompressing
the stream exactly comp_size bytes of input must have been consumed.
This is a minor improvement to error detection.
2021-01-17 19:20:50 +02:00
Lasse Collin 774cc0118b liblzma: Make EROFS LZMA decoder work when exact uncomp_size isn't known.
The caller must still not specify an uncompressed size bigger
than the actual uncompressed size.

As a downside, this now needs the exact compressed size.
2021-01-17 18:53:34 +02:00
Lasse Collin 421b0aa352 liblzma: Fix missing normalization in rc_encode_dummy().
Without this fix it could attempt to create too much output.
2021-01-14 20:57:11 +02:00
Lasse Collin 601ec0311e liblzma: Add EROFS LZMA encoder and decoder.
Right now this is just a planned extra-compact format for use
in the EROFS file system in Linux. At this point it's possible
that the format will either change or be abandoned and removed
completely.

The special thing about the encoder is that it uses the
output-size-limited encoding added in the previous commit.
EROFS uses fixed-sized blocks (e.g. 4 KiB) to hold compressed
data so the compressors must be able to create valid streams
that fill the given block size.
2021-01-14 20:10:59 +02:00
Lasse Collin 625f4c7c99 liblzma: Add rough support for output-size-limited encoding in LZMA1.
With this it is possible to encode LZMA1 data without EOPM so that
the encoder will encode as much input as it can without exceeding
the specified output size limit. The resulting LZMA1 stream will
be a normal LZMA1 stream without EOPM. The actual uncompressed size
will be available to the caller via the uncomp_size pointer.

One missing thing is that the LZMA layer doesn't inform the LZ layer
when the encoding is finished and thus the LZ may read more input
when it won't be used. However, this doesn't matter if encoding is
done with a single call (which is the planned use case for now).
For proper multi-call encoding this should be improved.

This commit only adds the functionality for internal use.
Nothing uses it yet.
2021-01-14 18:58:13 +02:00
Lasse Collin f7fa309e1f liblzma: Make lzma_outq usable for threaded decompression too.
Before this commit all output queue buffers were allocated as
a single big allocation. Now each buffer is allocated separately
when needed. Used buffers are cached to avoid reallocation
overhead but the cache will keep only one buffer size at a time.
This should make things work OK in the decompression where most
of the time the buffer sizes will be the same but with some less
common files the buffer sizes may vary.

While this should work fine, it's still a bit preliminary
and may even get reverted if it turns out to be useless for
decompression.
2021-01-09 22:18:23 +02:00
H.J. Lu 4fd79b90c5 liblzma: Enable Intel CET in x86 CRC assembly codes
When Intel CET is enabled, we need to include <cet.h> in assembly codes
to mark Intel CET support and add _CET_ENDBR to indirect jump targets.

Tested on Intel Tiger Lake under CET enabled Linux.
2020-12-23 17:13:33 +02:00
Lasse Collin b8e12f5ab4 Typo fixes from fossies.org.
https://fossies.org/linux/misc/xz-5.2.5.tar.xz/codespell.html
2020-03-23 18:07:50 +02:00
Lasse Collin 4572d53e16 liblzma: Fix a comment and RC_SYMBOLS_MAX.
The comment didn't match the value of RC_SYMBOLS_MAX and the value
itself was slightly larger than actually needed. The only harm
about this was that memory usage was a few bytes larger.
2020-03-02 13:54:33 +02:00
Lasse Collin b3ed19a55f liblzma: Remove unneeded <sys/types.h> from fastpos_tablegen.c.
This file only generates fastpos_table.c.
It isn't built as a part of liblzma.
2020-02-24 23:23:18 +02:00
Lasse Collin 7b8982b291 Use defined(__GNUC__) before __GNUC__ in preprocessor lines.
This should silence the equivalent of -Wundef in compilers that
don't define __GNUC__.
2020-02-22 14:15:07 +02:00
Lasse Collin 43dfe04e62 liblzma: Add more uses of lzma_memcmplen() to the normal mode of LZMA.
This gives a tiny encoder speed improvement. This could have been done
in 2014 after the commit 544aaa3d13 but
it was forgotten.
2020-02-21 17:40:02 +02:00
Lasse Collin 7136f1735c Rename unaligned_read32ne to read32ne, and similarly for the others. 2019-12-31 00:47:49 +02:00
Lasse Collin 5e78fcbf2e Rename read32ne to aligned_read32ne, and similarly for the others.
Using the aligned methods requires more care to ensure that
the address really is aligned, so it's nicer if the aligned
methods are prefixed. The next commit will remove the unaligned_
prefix from the unaligned methods which in liblzma are used in
more places than the aligned ones.
2019-12-31 00:29:48 +02:00
Lasse Collin 8ce679125d liblzma: Fix a buggy comment. 2019-06-25 23:15:21 +03:00
Lasse Collin d499e467d9 liblzma: Add a comment. 2019-06-24 23:52:17 +03:00
Lasse Collin a12b13c5f0 liblzma: Silence clang -Wmissing-variable-declarations. 2019-06-24 23:45:21 +03:00
Lasse Collin 1b4675cebf Add LZMA_RET_INTERNAL1..8 to lzma_ret and use one for LZMA_TIMED_OUT.
LZMA_TIMED_OUT is *internally* used as a value for lzma_ret
enumeration. Previously it was #defined to 32 and cast to lzma_ret.
That way it wasn't visible in the public API, but this was hackish.

Now the public API has eight LZMA_RET_INTERNALx members and
LZMA_TIMED_OUT is #defined to LZMA_RET_INTERNAL1. This way
the code is cleaner overall although the public API has a few
extra mysterious enum members.
2019-06-24 23:25:41 +03:00
Lasse Collin 608517b9b7 liblzma: Remove incorrect uses of lzma_attribute((__unused__)).
Caught by clang -Wused-but-marked-unused.
2019-06-24 22:50:36 +03:00
Lasse Collin dfac2c9a1d liblzma: Fix warnings from -Wsign-conversion.
Also, more parentheses were added to the literal_subcoder
macro in lzma_comon.h (better style but no functional change
in the current usage).
2019-06-23 21:38:56 +03:00
Lasse Collin 039a168e8c liblzma: Fix comments.
Thanks to Bruce Stark.
2019-06-03 20:41:54 +03:00
Lasse Collin c460f6defe liblzma: Fix one more unaligned read to use unaligned_read16ne(). 2019-06-02 00:50:59 +03:00
Lasse Collin 386394fc9f liblzma: memcmplen: Use ctz32() from tuklib_integer.h.
The same compiler-specific #ifdefs are already in tuklib_integer.h
2019-06-01 21:36:13 +03:00
Lasse Collin 33773c6f2a liblzma: Use unaligned_readXXne functions instead of type punning.
Now gcc -fsanitize=undefined should be clean.

Thanks to Jeffrey Walton.
2019-06-01 19:01:21 +03:00
Lasse Collin 2a22de439e liblzma: Avoid memcpy(NULL, foo, 0) because it is undefined behavior.
I should have always known this but I didn't. Here is an example
as a reminder to myself:

    int mycopy(void *dest, void *src, size_t n)
    {
        memcpy(dest, src, n);
        return dest == NULL;
    }

In the example, a compiler may assume that dest != NULL because
passing NULL to memcpy() would be undefined behavior. Testing
with GCC 8.2.1, mycopy(NULL, NULL, 0) returns 1 with -O0 and -O1.
With -O2 the return value is 0 because the compiler infers that
dest cannot be NULL because it was already used with memcpy()
and thus the test for NULL gets optimized out.

In liblzma, if a null-pointer was passed to memcpy(), there were
no checks for NULL *after* the memcpy() call, so I cautiously
suspect that it shouldn't have caused bad behavior in practice,
but it's hard to be sure, and the problematic cases had to be
fixed anyway.

Thanks to Jeffrey Walton.
2019-05-13 20:05:17 +03:00
Antoine Cœur 2fb0ddaa55 spelling 2019-05-11 20:52:37 +03:00
Lasse Collin a18ae42a79 liblzma: Don't verify header CRC32s if building for fuzz testing.
FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION is #defined when liblzma
is being built for fuzz testing.

Most fuzzed inputs would normally get rejected because of incorrect
CRC32 and the actual header decoding code wouldn't get fuzzed.
Disabling CRC32 checks avoids this problem. The fuzzer program
must still use LZMA_IGNORE_CHECK flag to disable verification of
integrity checks of uncompressed data.
2018-10-26 22:49:10 +03:00
Lasse Collin 3cbcaeb07e liblzma: Remove an always-true condition from lzma_index_cat().
This should help static analysis tools to see that newg
isn't leaked.

Thanks to Pavel Raiskup.
2018-07-27 16:02:58 +03:00
Lasse Collin 76762ae609 liblzma: Improve lzma_properties_decode() API documentation. 2018-05-19 21:23:25 +03:00
Lasse Collin 2267f5b0d2 Bump the version number to 5.3.1alpha. 2018-04-29 18:58:19 +03:00
Ben Boeckel bc19799169 nothrow: use noexcept for C++11 and newer
In C++11, the `throw()` specifier is deprecated and `noexcept` is
preffered instead.
2018-02-06 18:41:45 +02:00
Lasse Collin fb6d4f83cb liblzma: Remove incorrect #ifdef from range_common.h.
In most cases it was harmless but it could affect some
custom build systems.

Thanks to Pippijn van Steenhoven.
2018-02-06 18:02:48 +02:00
Lasse Collin 94e3f986aa Fix or hide warnings from GCC 7's -Wimplicit-fallthrough. 2017-08-14 20:08:33 +03:00
Lasse Collin e353d0b1cc liblzma: Add lzma_file_info_decoder(). 2017-04-24 19:48:04 +03:00
Lasse Collin 8c9842c265 liblzma: Rename LZMA_SEEK to LZMA_SEEK_NEEDED and seek_in to seek_pos. 2017-04-21 15:05:16 +03:00
Lasse Collin 310d19816d liblzma: Make lzma_index_decoder_init() visible to other liblzma funcs.
This is to allow other functions to use it without going
via the public API (lzma_index_decoder()).
2017-03-30 20:03:05 +03:00
Lasse Collin a27920002d liblzma: Add generic support for input seeking (LZMA_SEEK).
Also mention LZMA_SEEK in xz/message.c to silence a warning.
2017-03-30 20:00:09 +03:00
Lasse Collin a0b1dda409 liblzma: Fix lzma_memlimit_set(strm, 0).
The 0 got treated specially in a buggy way and as a result
the function did nothing. The API doc said that 0 was supposed
to return LZMA_PROG_ERROR but it didn't.

Now 0 is treated as if 1 had been specified. This is done because
0 is already used to indicate an error from lzma_memlimit_get()
and lzma_memusage().

In addition, lzma_memlimit_set() no longer checks that the new
limit is at least LZMA_MEMUSAGE_BASE. It's counter-productive
for the Index decoder and was actually needed only by the
auto decoder. Auto decoder has now been modified to check for
LZMA_MEMUSAGE_BASE.
2017-03-30 19:51:14 +03:00
Lasse Collin 84462afaad liblzma: Similar memlimit fix for stream_, alone_, and auto_decoder. 2017-03-30 19:16:55 +03:00
Lasse Collin cbc7401793 liblzma: Fix handling of memlimit == 0 in lzma_index_decoder().
It returned LZMA_PROG_ERROR, which was done to avoid zero as
the limit (because it's a special value elsewhere), but using
LZMA_PROG_ERROR is simply inconvenient and can cause bugs.

The fix/workaround is to treat 0 as if it were 1 byte. It's
effectively the same thing. The only weird consequence is
that then lzma_memlimit_get() will return 1 even when 0 was
specified as the limit.

This fixes a very rare corner case in xz --list where a specific
memory usage limit and a multi-stream file could print the
error message "Internal error (bug)" instead of saying that
the memory usage limit is too low.
2017-03-30 19:10:55 +03:00
Lasse Collin d4a0462abe liblzma: Avoid multiple definitions of lzma_coder structures.
Only one definition was visible in a translation unit.
It avoided a few casts and temp variables but seems that
this hack doesn't work with link-time optimizations in compilers
as it's not C99/C11 compliant.

Fixes:
http://www.mail-archive.com/xz-devel@tukaani.org/msg00279.html
2016-11-21 20:24:50 +02:00
Lasse Collin ac398c3baf liblzma: Disable external SHA-256 by default.
This is the sane thing to do. The conflict with OpenSSL
on some OSes and especially that the OS-provided versions
can be significantly slower makes it clear that it was
a mistake to have the external SHA-256 support enabled by
default.

Those who want it can now pass --enable-external-sha256 to
configure. INSTALL was updated with notes about OSes where
this can be a bad idea.

The SHA-256 detection code in configure.ac had some bugs that
could lead to a build failure in some situations. These were
fixed, although it doesn't matter that much now that the
external SHA-256 is disabled by default.

MINIX >= 3.2.0 uses NetBSD's libc and thus has SHA256_Init
in libc instead of libutil. Support for the libutil version
was removed.
2016-03-13 20:21:49 +02:00
Lasse Collin 14115f84a3 liblzma: Make Valgrind happier with optimized (gcc -O2) liblzma.
When optimizing, GCC can reorder code so that an uninitialized
value gets used in a comparison, which makes Valgrind unhappy.
It doesn't happen when compiled with -O0, which I tend to use
when running Valgrind.

Thanks to Rich Prohaska. I remember this being mentioned long
ago by someone else but nothing was done back then.
2015-11-04 23:14:00 +02:00
Lasse Collin f4c95ba94b liblzma: Rename lzma_presets.c back to lzma_encoder_presets.c.
It would be too annoying to update other build systems
just because of this.
2015-11-03 20:55:45 +02:00
Lasse Collin 4cc584985c Build: Build LZMA1/2 presets also when only decoder is wanted.
People shouldn't rely on the presets when decoding raw streams,
but xz uses the presets as the starting point for raw decoder
options anyway.

lzma_encocder_presets.c was renamed to lzma_presets.c to
make it clear it's not used solely by the encoder code.
2015-11-03 18:06:40 +02:00
Lasse Collin b0bc3e0385 Build: Don't omit lzma_cputhreads() unless using --disable-threads.
Previously it was omitted if encoders were disabled
with --disable-encoders. It didn't make sense and
it also broke the build.
2015-11-03 17:41:54 +02:00
Lasse Collin c6bf438ab3 liblzma: Fix a build failure related to external SHA-256 support.
If an appropriate header and structure were found by configure,
but a library with a usable SHA-256 functions wasn't, the build
failed.
2015-11-02 18:16:51 +02:00
Lasse Collin 21515d79d7 liblzma: Fix lzma_index_dup() for empty Streams.
Stream Flags and Stream Padding weren't copied from
empty Streams.
2015-10-12 20:45:15 +03:00
Lasse Collin 09f395b6b3 liblzma: Add a note to index.c for those using static analyzers. 2015-10-12 20:31:44 +03:00
Lasse Collin 3bf857edfe liblzma: Fix a memory leak in error path of lzma_index_dup().
lzma_index_dup() calls index_dup_stream() which, in case of
an error, calls index_stream_end() to free memory allocated
by index_stream_init(). However, it illogically didn't
actually free the memory. To make it logical, the tree
handling code was modified a bit in addition to changing
index_stream_end().

Thanks to Evan Nemerson for the bug report.
2015-10-12 20:29:09 +03:00
Lasse Collin fbbb295a91 liblzma: A MSVC-specific hack isn't needed with MSVC 2013 and newer. 2015-07-12 20:48:19 +03:00
Lasse Collin 3717885f9e Bump version to 5.3.0alpha and soname to 5.3.99.
The idea of 99 is that it looks a bit weird in this context.
For new features there's no API/ABI stability in devel versions.
2015-03-30 22:44:02 +03:00
Lasse Collin f243f5f44c liblzma: Silence more uint32_t vs. size_t warnings. 2015-03-07 22:01:00 +02:00
Lasse Collin f6ec468015 liblzma: Fix a warning in index.c. 2015-03-07 19:33:17 +02:00
Lasse Collin dec11497a7 Bump version and soname for 5.2.1. 2015-02-26 16:53:44 +02:00
Lasse Collin 117d962685 liblzma: Fix a compression-ratio regression in LZMA1/2 in fast mode.
The bug was added in the commit
f48fce093b and thus
affected 5.1.4beta and 5.2.0. Luckily the bug cannot
cause data corruption or other nasty things.
2015-02-21 23:40:26 +02:00
Lasse Collin c45757135f liblzma: Set LZMA_MEMCMPLEN_EXTRA depending on the compare method. 2015-01-26 21:24:39 +02:00
Lasse Collin fec88d41e6 liblzma: Silence harmless Valgrind errors.
Thanks to Torsten Rupp for reporting this. I had
forgotten to run Valgrind before the 5.2.0 release.
2015-01-26 20:39:28 +02:00
Lasse Collin 6060f7dc76 Bump version and soname for 5.2.0.
I know that soname != app version, but I skip AGE=1
in -version-info to make the soname match the liblzma
version anyway. It doesn't hurt anything as long as
it doesn't conflict with library versioning rules.
2014-12-21 18:11:17 +02:00
Lasse Collin 1190c641af liblzma: Document how lzma_mt.block_size affects memory usage. 2014-12-02 20:04:07 +02:00
Lasse Collin 34f9e40a0a Remove LZMA_UNSTABLE macro. 2014-11-26 20:12:27 +02:00
Lasse Collin 6d9c0ce9f2 liblzma: Update lzma_stream_encoder_mt() API docs. 2014-11-26 20:10:33 +02:00
Lasse Collin 2301f3f05d liblzma: Verify the filter chain in threaded encoder initialization.
This way an invalid filter chain is detected at the Stream
encoder initialization instead of delaying it to the first
call to lzma_code() which triggers the initialization of
the actual filter encoder(s).
2014-11-25 12:32:05 +02:00
Lasse Collin 7716dcf9df liblzma: Fix lzma_mt.preset in lzma_stream_encoder_mt_memusage().
It read the filter chain from a wrong variable. This is a similar
bug that was fixed in 9494fb6d0f.
2014-11-10 15:38:47 +02:00
Lasse Collin c923b140b2 Build: Prepare to support Automake's subdir-objects.
Due to a bug in Automake, subdir-objects won't be enabled
for now.

http://debbugs.gnu.org/cgi/bugreport.cgi?bug=17354

Thanks to Daniel Richard G. for the original patches.
2014-10-29 21:15:35 +02:00
Lasse Collin d62028b4c1 liblzma: Fix a portability problem in Makefile.am.
POSIX supports $< only in inference rules (suffix rules).
Using it elsewhere is a GNU make extension and doesn't
work e.g. with OpenBSD make.

Thanks to Christian Weisgerber for the patch.
2014-09-20 19:42:56 +03:00
Lasse Collin c35de31d42 Bump the version number to 5.1.4beta. 2014-09-14 21:54:09 +03:00
Lasse Collin 9adbc2ff37 liblzma: Add support for LZMA_IGNORE_CHECK. 2014-08-05 22:15:07 +03:00
Lasse Collin 0e0f34b8e4 liblzma: Add support for lzma_block.ignore_check.
Note that this slightly changes how lzma_block_header_decode()
has been documented. Earlier it said that the .version is set
to the lowest required value, but now it says that the .version
field is kept unchanged if possible. In practice this doesn't
affect any old code, because before this commit the only
possible .version was 0.
2014-08-05 22:03:30 +03:00
Lasse Collin 71e1437ab5 liblzma: Use lzma_memcmplen() in the BT3 match finder.
I had missed this when writing the commit
5db75054e9.

Thanks to Jun I Jin.
2014-08-04 19:25:58 +03:00
Lasse Collin 5dcffdbcc2 liblzma: SHA-256: Optimize the Maj macro slightly.
The Maj macro is used where multiple things are added
together, so making Maj a sum of two expressions allows
some extra freedom for the compiler to schedule the
instructions.

I learned this trick from
<http://www.hackersdelight.org/corres.txt>.
2014-08-03 21:32:25 +03:00
Lasse Collin a9477d1e0c liblzma: SHA-256: Optimize the way rotations are done.
This looks weird because the rotations become sequential,
but it helps quite a bit on both 32-bit and 64-bit x86:

  - It requires fewer instructions on two-operand
    instruction sets like x86.

  - It requires one register less which matters especially
    on 32-bit x86.

I hope this doesn't hurt other archs.

I didn't invent this idea myself, but I don't remember where
I saw it first.
2014-08-03 21:08:12 +03:00
Lasse Collin 5a76c7c8ee liblzma: SHA-256: Remove the GCC #pragma that became unneeded.
The unrolling in the previous commit should avoid the
situation where a compiler may think that an uninitialized
variable might be accessed.
2014-08-03 20:38:13 +03:00
Lasse Collin 9a096f8e57 liblzma: SHA-256: Unroll a little more.
This way a branch isn't needed for each operation
to choose between blk0 and blk2, and still the code
doesn't grow as much as it would with full unrolling.
2014-08-03 20:33:38 +03:00
Lasse Collin bc7650d87b liblzma: SHA-256: Do the byteswapping without a temporary buffer. 2014-08-03 19:56:43 +03:00
Lasse Collin 544aaa3d13 liblzma: Use lzma_memcmplen() in normal mode of LZMA.
Two locations were not changed yet because the simplest change
assumes that the initial "len" may be greater than "limit".
2014-07-25 22:38:28 +03:00
Lasse Collin f48fce093b liblzma: Simplify LZMA fast mode code by using memcmp(). 2014-07-25 22:30:38 +03:00
Lasse Collin 6bf5308e34 liblzma: Use lzma_memcmplen() in fast mode of LZMA. 2014-07-25 22:29:49 +03:00
Lasse Collin 5db75054e9 liblzma: Use lzma_memcmplen() in the match finders.
This doesn't change the match finder output.
2014-07-25 21:15:07 +03:00
Lasse Collin e1c8f1d01f liblzma: Add lzma_memcmplen() for fast memory comparison.
This commit just adds the function. Its uses will be in
separate commits.

This hasn't been tested much yet and it's perhaps a bit early
to commit it but if there are bugs they should get found quite
quickly.

Thanks to Jun I Jin from Intel for help and for pointing out
that string comparison needs to be optimized in liblzma.
2014-07-25 20:57:20 +03:00
Lasse Collin a115cc3748 liblzma: Add lzma_cputhreads(). 2014-06-18 22:04:24 +03:00
Lasse Collin da1718f266 liblzma: Use lzma_alloc_zero() in LZ encoder initialization.
This avoids a memzero() call for a newly-allocated memory,
which can be expensive when encoding small streams with
an over-sized dictionary.

To avoid using lzma_alloc_zero() for memory that doesn't
need to be zeroed, lzma_mf.son is now allocated separately,
which requires handling it separately in normalize() too.

Thanks to Vincenzo Innocente for reporting the problem.
2014-05-25 21:45:56 +03:00