bpf: clean up btf_scan_decl_tags()

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Refactor the newly introduced btf_scan_decl_tags() to improve
readability and maintainability. The current implementation uses a
manual if-else chain and a magic number offset to strip the "arg:"
prefix from declaration tags.

Replace the if-else logic with a table-driven approach using a static
const array. This separates the tag data from the scanning logic, making
the helper more extensible for future tags. Additionally, replace the
magic number '4' with a sizeof-based calculation on the prefix string to
ensure the offset remains synchronized with the search key.

Finally, optimize the loop by moving the is_global check to the top of
the block. This allows the verifier to fail-fast on static subprograms
without performing unnecessary BTF string and type lookups.

Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/r/20260603201822.770596-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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Matt Bobrowski 2026-06-03 20:18:22 +00:00 • committed by Alexei Starovoitov

parent 5b88319e47

commit fbd6dc50d9

1 changed files with 30 additions and 16 deletions

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kernel/bpf/btf.c

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