I know nothing about Kbuild, I can only confirm that this patch fixes the problem I encountered in practice. On 08/28, Alexey Gladkov wrote: > > $ touch kernel/bpf/core.c > $ make C=2 CHECK=true kernel/bpf/core.o > > Outputs: > > CHECK scripts/mod/empty.c > CALL scripts/checksyscalls.sh > DESCEND objtool > INSTALL libsubcmd_headers > CC kernel/bpf/core.o > > As can be seen the compilation is done, but CHECK is not executed. And after that $ make C=2 CHECK=true kernel/bpf/core.o CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CHECK is also not executed. compare with, for example, $ touch kernel/trace/trace.c $ make C=2 CHECK=true kernel/trace/trace.o CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CC kernel/trace/trace.o CHECK kernel/trace/trace.c $ make C=2 CHECK=true kernel/trace/trace.o CHECK scripts/mod/empty.c CALL scripts/checksyscalls.sh DESCEND objtool INSTALL libsubcmd_headers CHECK kernel/trace/trace.c Tested-by: Oleg Nesterov <oleg@xxxxxxxxxx>