cc  -O2 -pipe ... -std=gnu11 -Werror -DKLD_MODULE -nostdinc ... -c /root/poc/dmabuf_demo.c
cc -Wl,--build-id=sha1 -nostdlib -Wl,--hash-style=sysv   -r -Wl,-d -o dmabugdemo.ko dmabuf_demo.o
cc -O -o leak_trigger leak_trigger.c      (no warnings)