This restores the old behavior that existed before 2013-02-22, when
changes were made by 64dbfb444c ("decompressors: drop dependency on
CONFIG_EXPERT") and 5dc49c75a2 ("decompressors: make the default
XZ_DEC_* config match the selected architecture").
Disabling the filters only makes sense on embedded systems.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Acked-by: Kyle McMartin <kyle@infradead.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 5dc49c75a2 ("decompressors: make the default XZ_DEC_* config
match the selected architecture") added
default y if POWERPC
to lib/xz/Kconfig. But there is no Kconfig symbol POWERPC. The most
general Kconfig symbol for the powerpc architecture is PPC. So let's
use that.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Lasse Collin <lasse.collin@tukaani.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the defautl XZ_DEC_* config symbol to match the configured
architecture. It is perfectly legitimate to support multiple XZ BCJ
filters for different architectures (e.g.: to mount foreign squashfs/xz
compressed filesystems), it is however more natural not to select them all
by default, but only the one matching the configured architecture.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the XZ_DEC_* depedencey on CONFIG_EXPERT as recommended by Lasse
Colin.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Group all architecture-specific BCJ filter configuration symbols under an
if XZ_BCJ / endif statement.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Acked-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
xz_dec_run() could incorrectly return XZ_BUF_ERROR if all of the
following was true:
- The caller knows how many bytes of output to expect and only provides
that much output space.
- When the last output bytes are decoded, the caller-provided input
buffer ends right before the LZMA2 end of payload marker. So LZMA2
won't provide more output anymore, but it won't know it yet and thus
won't return XZ_STREAM_END yet.
- A BCJ filter is in use and it hasn't left any unfiltered bytes in the
temp buffer. This can happen with any BCJ filter, but in practice
it's more likely with filters other than the x86 BCJ.
This fixes <https://bugzilla.redhat.com/show_bug.cgi?id=735408> where
Squashfs thinks that a valid file system is corrupt.
This also fixes a similar bug in single-call mode where the uncompressed
size of a block using BCJ + LZMA2 was 0 bytes and caller provided no
output space. Many empty .xz files don't contain any blocks and thus
don't trigger this bug.
This also tweaks a closely related detail: xz_dec_bcj_run() could call
xz_dec_lzma2_run() to decode into temp buffer when it was known to be
useless. This was harmless although it wasted a minuscule number of CPU
cycles.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
<linux/kernel.h> is needed for min_t. The old version
happened to work on x86 because <asm/unaligned.h>
indirectly includes <linux/kernel.h>, but it didn't
work on ARM.
<linux/kernel.h> includes <asm/byteorder.h> so it's
not necessary to include it explicitly anymore.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The old code considered valid empty LZMA2 streams to be corrupt.
Note that a typical empty .xz file has no LZMA2 data at all,
and thus most .xz files having no uncompressed data are handled
correctly even without this fix.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.
This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel. A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).
Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In userspace, the .lzma format has become mostly a legacy file format that
got superseded by the .xz format. Similarly, LZMA Utils was superseded by
XZ Utils.
These patches add support for XZ decompression into the kernel. Most of
the code is as is from XZ Embedded <http://tukaani.org/xz/embedded.html>.
It was written for the Linux kernel but is usable in other projects too.
Advantages of XZ over the current LZMA code in the kernel:
- Nice API that can be used by other kernel modules; it's
not limited to kernel, initramfs, and initrd decompression.
- Integrity check support (CRC32)
- BCJ filters improve compression of executable code on
certain architectures. These together with LZMA2 can
produce a few percent smaller kernel or Squashfs images
than plain LZMA without making the decompression slower.
This patch: Add the main decompression code (xz_dec), testing module
(xz_dec_test), wrapper script (xz_wrap.sh) for the xz command line tool,
and documentation. The xz_dec module is enough to have a usable XZ
decompressor e.g. for Squashfs.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Lasse Collin
Paul Bolle
Florian Fainelli
David Rientjes