WARNING: externs should be avoided in .c files
#85: FILE: tools/testing/selftests/bpf/progs/task_storage_nodeadlock.c:13:
+extern bool CONFIG_PREEMPTION __kconfig __weak;

total: 0 errors, 1 warnings, 0 checks, 50 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 3c54357076cc ("selftests/bpf: Check for PREEMPTION instead of PREEMPT") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE 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, 1 warnings, 0 checks, 50 lines checked