CHECK: extern prototypes should be avoided in .h files #56: FILE: include/linux/can/core.h:61: +extern void can_set_skb_uid(struct sk_buff *skb); total: 0 errors, 0 warnings, 1 checks, 147 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 1e71462dde05 ("can: use skb hash instead of private variable in headroom") 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, 0 warnings, 1 checks, 147 lines checked