WARNING: Macros with flow control statements should be avoided
#102: FILE: kernel/bpf/syscall.c:2870:
+#define DEFINE_BPF_MULTI_FUNC(args...)			\
+	extern int bpf_multi_func(args);		\
+	int __init bpf_multi_func(args) { return 0; }

WARNING: externs should be avoided in .c files
#103: FILE: kernel/bpf/syscall.c:2871:
+	extern int bpf_multi_func(args);		\

WARNING: line length of 95 exceeds 80 columns
#155: FILE: kernel/bpf/syscall.c:3021:
+	prog->aux->attach_btf_id = multi_func ? bpf_multi_func_btf_id[0] : attr->attach_btf_id;

WARNING: line length of 82 exceeds 80 columns
#186: FILE: kernel/bpf/trampoline.c:152:
+		    eatype == BPF_MODIFY_RETURN || eatype == BPF_TRACE_FSESSION ||

WARNING: line length of 88 exceeds 80 columns
#187: FILE: kernel/bpf/trampoline.c:153:
+		    eatype == BPF_TRACE_FENTRY_MULTI || eatype == BPF_TRACE_FEXIT_MULTI)

total: 0 errors, 5 warnings, 0 checks, 189 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 a49c1c327f7b ("bpf: Add multi tracing attach types") 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, 5 warnings, 0 checks, 189 lines checked