kernel/linux.git/lib/xz, branch v6.6.132

xz: cleanup CRC32 edits from 2018

2024-10-04T14:29:19+00:00

[ Upstream commit 2ee96abef214550d9e92f5143ee3ac1fd1323e67 ] In 2018, a dependency on was added to avoid duplicating the same constant in multiple files. Two months later it was found to be a bad idea and the definition of CRC32_POLY_LE macro was moved into xz_private.h to avoid including . xz_private.h is a wrong place for it too. Revert back to the upstream version which has the poly in xz_crc32_init() in xz_crc32.c. Link: https://lkml.kernel.org/r/20240721133633.47721-10-lasse.collin@tukaani.org Fixes: faa16bc404d7 ("lib: Use existing define with polynomial") Fixes: 242cdad873a7 ("lib/xz: Put CRC32_POLY_LE in xz_private.h") Signed-off-by: Lasse Collin Reviewed-by: Sam James Tested-by: Michael Ellerman (powerpc) Cc: Krzysztof Kozlowski Cc: Herbert Xu Cc: Joel Stanley Cc: Albert Ou Cc: Catalin Marinas Cc: Emil Renner Berthing Cc: Greg Kroah-Hartman Cc: Jonathan Corbet Cc: Jubin Zhong Cc: Jules Maselbas Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Randy Dunlap Cc: Rui Li Cc: Simon Glass Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

lib/xz, lib/decompress_unxz.c: Fix spelling in comments

2021-10-19T15:44:30+00:00

uncompressible -> incompressible non-splitted -> non-split Link: https://lore.kernel.org/r/20211010213145.17462-6-xiang@kernel.org Signed-off-by: Lasse Collin Signed-off-by: Gao Xiang

lib/xz: Add MicroLZMA decoder

2021-10-19T15:44:30+00:00

MicroLZMA is a yet another header format variant where the first byte of a raw LZMA stream (without the end of stream marker) has been replaced with a bitwise-negation of the lc/lp/pb properties byte. MicroLZMA was created to be used in EROFS but can be used by other things too where wasting minimal amount of space for headers is important. This is implemented using most of the LZMA2 code as is so the amount of new code is small. The API has a few extra features compared to the XZ decoder. On the other hand, the API lacks XZ_BUF_ERROR support which is important to take into account when using this API. MicroLZMA doesn't support BCJ filters. In theory they could be added later as there are many unused/reserved values for the first byte of the compressed stream but in practice it is somewhat unlikely to happen due to a few implementation reasons. Link: https://lore.kernel.org/r/20211010213145.17462-5-xiang@kernel.org Signed-off-by: Lasse Collin Signed-off-by: Gao Xiang

lib/xz: Move s->lzma.len = 0 initialization to lzma_reset()

2021-10-19T15:44:30+00:00

It's a more logical place even if the resetting needs to be done only once per LZMA2 stream (if lzma_reset() called in the middle of an LZMA2 stream, .len will already be 0). Link: https://lore.kernel.org/r/20211010213145.17462-4-xiang@kernel.org Signed-off-by: Lasse Collin Signed-off-by: Gao Xiang

lib/xz: Validate the value before assigning it to an enum variable

2021-10-19T15:44:30+00:00

This might matter, for example, if the underlying type of enum xz_check was a signed char. In such a case the validation wouldn't have caught an unsupported header. I don't know if this problem can occur in the kernel on any arch but it's still good to fix it because some people might copy the XZ code to their own projects from Linux instead of the upstream XZ Embedded repository. This change may increase the code size by a few bytes. An alternative would have been to use an unsigned int instead of enum xz_check but using an enumeration looks cleaner. Link: https://lore.kernel.org/r/20211010213145.17462-3-xiang@kernel.org Signed-off-by: Lasse Collin Signed-off-by: Gao Xiang

lib/xz: Avoid overlapping memcpy() with invalid input with in-place decompression

2021-10-19T15:44:30+00:00

With valid files, the safety margin described in lib/decompress_unxz.c ensures that these buffers cannot overlap. But if the uncompressed size of the input is larger than the caller thought, which is possible when the input file is invalid/corrupt, the buffers can overlap. Obviously the result will then be garbage (and usually the decoder will return an error too) but no other harm will happen when such an over-run occurs. This change only affects uncompressed LZMA2 chunks and so this should have no effect on performance. Link: https://lore.kernel.org/r/20211010213145.17462-2-xiang@kernel.org Signed-off-by: Lasse Collin Signed-off-by: Gao Xiang

lib/decompressors: fix spelling mistakes

2021-07-01T18:06:05+00:00

Fix some spelling mistakes in comments: sentinal ==> sentinel compresed ==> compressed dependeny ==> dependency immediatelly ==> immediately dervied ==> derived splitted ==> split nore ==> not independed ==> independent asumed ==> assumed Link: https://lkml.kernel.org/r/20210604085656.12257-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei Cc: Jiri Kosina Cc: Thomas Bogendoerfer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Revert "lib: Revert use of fallthrough pseudo-keyword in lib/"

2020-11-18T20:15:17+00:00

This reverts commit 6a9dc5fd6170 ("lib: Revert use of fallthrough pseudo-keyword in lib/") Now that we can build arch/powerpc/boot/ free of -Wimplicit-fallthrough, re-enable these fixes for lib/. Signed-off-by: Nick Desaulniers Tested-by: Nathan Chancellor Reviewed-by: Nathan Chancellor Reviewed-by: Gustavo A. R. Silva Reviewed-by: Miguel Ojeda Link: https://github.com/ClangBuiltLinux/linux/issues/236 Signed-off-by: Gustavo A. R. Silva

lib: Revert use of fallthrough pseudo-keyword in lib/

2020-08-24T21:17:44+00:00

The following build error for powerpc64 was reported by Nathan Chancellor: "$ scripts/config --file arch/powerpc/configs/powernv_defconfig -e KERNEL_XZ $ make -skj"$(nproc)" ARCH=powerpc CROSS_COMPILE=powerpc64le-linux- distclean powernv_defconfig zImage ... In file included from arch/powerpc/boot/../../../lib/decompress_unxz.c:234, from arch/powerpc/boot/decompress.c:38: arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c: In function 'dec_main': arch/powerpc/boot/../../../lib/xz/xz_dec_stream.c:586:4: error: 'fallthrough' undeclared (first use in this function) 586 | fallthrough; | ^~~~~~~~~~~ This will end up affecting distribution configurations such as Debian and OpenSUSE according to my testing. I am not sure what the solution is, the PowerPC wrapper does not set -D__KERNEL__ so I am not sure that compiler_attributes.h can be safely included." In order to avoid these sort of problems, it seems that the best solution is to use /* fall through */ comments instead of the fallthrough pseudo-keyword macro in lib/, for now. Reported-by: Nathan Chancellor Fixes: df561f6688fe ("treewide: Use fallthrough pseudo-keyword") Signed-off-by: Gustavo A. R. Silva Reviewed-and-tested-by: Nathan Chancellor Signed-off-by: Linus Torvalds

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva