PR #2784 introduced a bug in the decompressor that caused some valid
inputs to fail to decompress. The bitstream isn't reloaded after the 4X*
loop if the number of elements remaining is small enough, causing us to
read more bits than are available in the bitcontainer.
This was caught by the MSAN fuzzer in OSS-Fuzz because the assembly
implementation isn't used in the MSAN build.
Credit to OSS-Fuzz.
Multiple ZSTD_createDCtx* functions call other (public)
ZSTD_createDCtx* functions, this makes it harder for humans
and compilers to throw out code that is not used.
This farms out the logic into a static function, if a program
only uses a single ZSTD_createDCtx variant, all others can be easily
dropped and the remaining implementation can be specialized.
Switch to a macro `ZSTD_FALLTHROUGH;` instead of a comment. On supported
compilers this uses an attribute, otherwise it becomes a comment.
This is necessary to be compatible with clang's `-Wfall-through`, and
gcc's `-Wfall-through=2` which don't support comments. Without this the
linux build emits a bunch of warnings.
Also add a test to CI to ensure that we don't regress.
turns out, it's possible to constify MatchState* parameter
in some parts of the binary tree algorithm,
making it a pure read-only parameter,
as opposed to a mutable state.
This is supposed to be helpful for both maintenance and the compiler.
The mentioned path is being created/used by the 'import' rule for
generating source files for Linux kernel.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Commit a5f2c4552803 ("Huffman ASM") added a new ASM source file,
but it wasn't added to the kernel Makefile despite that it received
support for Huffman ASM according to the internal definitions. This
leads to undefined references, as huf_decompress.o now calls those
ASM functions.
Add it to the list of sources when building inside the kernel tree.
Kbuild can handle .S files just fine, so none additional rules
needed.
Fixes: a5f2c4552803 ("Huffman ASM")
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Linux 5.15 introduces a new Kconfig option, CONFIG_WERROR, which
forces -Werror for the entire kernel.
Current in-kernel ZSTD implementation uses functions deprecated
in 1.5.0, and thus fails on -Wdeprecated-declarations.
Turn this particular error into warning to be able to build the
kernel with CONFIG_WERROR. I'm not disabling them completely to
make sure they'll be visible and [hopefully] fixed sooner or later.
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
Instead of calling `ZSTD_compress_advanced()` and
`ZSTD_initCStream_advanced()`, which each take a `ZSTD_parameters` by
value, use the new advanced API.
Stack usage went from 2024 -> 1944.
