bpf: Add btf_type_is_arena_ptr()

Add btf_type_is_arena_ptr() to test whether a BTF type is a pointer
carrying the "arena" type tag, and use it to simplify both
btf_scan_type_tags() and btf_validate_return_type(). The helper has
external linkage because a later patch calls it from verifier.c to
decide whether a struct member returned by value may be an arena
pointer.

btf_scan_type_tags() drove btf_type_tag_walk() with a one-entry match
table, so the "multiple type tags" error it checked for could never
fire: btf_type_tag_walk() only fails when the walk sets more than one
flag. Dropping that error path, and with it the int return, is
therefore no functional change.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20260829061529.1693266-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

0 files changed, 0 insertions, 0 deletions