From: Johannes Berg <johannes.berg@xxxxxxxxx> commit b5642479b0f7168fe16d156913533fe65ab4f8d5 upstream. If all net/wireless/certs/*.hex files are deleted, the build will hang at this point since the 'cat' command will have no arguments. Do "echo | cat - ..." so that even if the "..." part is empty, the whole thing won't hang. Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx> Link: https://lore.kernel.org/r/iwlwifi.20210618133832.c989056c3664.Ic3b77531d00b30b26dcd69c64e55ae2f60c3f31e@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/wireless/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/wireless/Makefile +++ b/net/wireless/Makefile @@ -28,7 +28,7 @@ $(obj)/shipped-certs.c: $(wildcard $(src @$(kecho) " GEN $@" @(echo '#include "reg.h"'; \ echo 'const u8 shipped_regdb_certs[] = {'; \ - cat $^ ; \ + echo | cat - $^ ; \ echo '};'; \ echo 'unsigned int shipped_regdb_certs_len = sizeof(shipped_regdb_certs);'; \ ) > $@
