Stanislav Fomichev <sdf@xxxxxxxxxx> writes: [..] > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c > index d434a994ee04..c3e501e3e39c 100644 > --- a/kernel/bpf/core.c > +++ b/kernel/bpf/core.c > @@ -2097,6 +2097,13 @@ bool bpf_prog_map_compatible(struct bpf_map *map, > if (fp->kprobe_override) > return false; > > + /* When tail-calling from a non-dev-bound program to a dev-bound one, > + * XDP metadata helpers should be disabled. Until it's implemented, > + * prohibit adding dev-bound programs to tail-call maps. > + */ > + if (bpf_prog_is_dev_bound(fp->aux)) > + return false; > + nit: the comment is slightly inaccurate as the program running in a devmap/cpumap has nothing to do with tail calls. maybe replace it with: "XDP programs inserted into maps are not guaranteed to run on a particular netdev (and can run outside driver context entirely in the case of devmap and cpumap). Until device checks are implemented, prohibit adding dev-bound programs to program maps." Also, there needs to be a check in bpf_prog_test_run_xdp() to reject dev-bound programs there as well... -Toke
