Re: [PATCH v2 08/15] lib/lz4: add the build environment for the vendored sources

[sashiko-bot@kernel.org]

> lz4_deps.h makes the vendored upstream sources build in the kernel. It
> gives every upstream entry point internal linkage, so an object carries
> only the codec it forwards, selects heap mode with failing allocators so
> LZ4HC's ~64K optimal-parser buffer stays off the stack, and renames the
> entry points the kernel re-exports so the kernel's own definitions can
> use the real names. LZ4LIB_VISIBILITY carries __maybe_unused for the
> functions an object does not use.
> 
> freestanding/ forwards the four ISO C headers upstream includes to their
> <linux/> equivalents. lz4_kernel_api.h undoes the renaming; it carries
> its own copy of the exported prototypes until a later patch can include
> <linux/lz4.h> instead.
> 
> Two settings upstream leaves to the build:
> 
>  - Unaligned access goes through memcpy() where the architecture has
>    efficient unaligned access, and through packed structs, as
>    get_unaligned() does, elsewhere. Left alone, upstream uses plain
>    misaligned loads on ARMv6.
> 
>  - On ppc64le, lz4.c marks functions __attribute__((optimize("O2"))) for
>    GCC, which drops command line options such as -fno-strict-aliasing
>    for them; see commit 080b6f407635 ("bpf: Don't rely on GCC
>    __attribute__((optimize)) to disable GCSE"). lz4_deps.h defines
>    optimize() to nothing for upstream's sources.
> 
> Nothing includes either header yet.
> 
> Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261106-lz4-vendor-upstream-v2-0-ee04c3f0d7dc@samsung.com?part=8