WARNING: 'avaiable' may be misspelled - perhaps 'available'?
#30: 
the BTF record is populated and (at that point) avaiable for inspection
                                                ^^^^^^^^

WARNING: line length of 83 exceeds 80 columns
#133: FILE: kernel/bpf/hashtab.c:499:
+static int htab_set_dtor(const struct bpf_htab *htab, void (*dtor)(void *, void *))

WARNING: Prefer kzalloc_obj over kzalloc with sizeof
#144: FILE: kernel/bpf/hashtab.c:510:
+	hrec = kzalloc(sizeof(*hrec), GFP_KERNEL);

WARNING: line length of 91 exceeds 80 columns
#156: FILE: kernel/bpf/hashtab.c:522:
+	bpf_mem_alloc_set_dtor((struct bpf_mem_alloc *)ma, dtor, htab_dtor_ctx_free, hrec);

WARNING: line length of 97 exceeds 80 columns
#161: FILE: kernel/bpf/hashtab.c:527:
+			      const struct btf_type *key_type, const struct btf_type *value_type)

WARNING: line length of 84 exceeds 80 columns
#230: FILE: kernel/bpf/memalloc.c:265:
+static int free_all(struct bpf_mem_cache *c, struct llist_node *llnode, bool percpu)

WARNING: line length of 81 exceeds 80 columns
#264: FILE: kernel/bpf/memalloc.c:424:
+		free_all(c, llist_del_all(&c->waiting_for_gp), !!c->percpu_size);

WARNING: line length of 89 exceeds 80 columns
#304: FILE: kernel/bpf/memalloc.c:1025:
+void bpf_mem_alloc_set_dtor(struct bpf_mem_alloc *ma, void (*dtor)(void *obj, void *ctx),

total: 0 errors, 8 warnings, 0 checks, 249 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Commit e6e45f943e40 ("bpf: Register dtor for freeing special fields") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE FILE_PATH_CHANGES GIT_COMMIT_ID MACRO_ARG_REUSE NO_AUTHOR_SIGN_OFF

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.
total: 0 errors, 8 warnings, 0 checks, 249 lines checked