Il giorno gio 25 lug 2024 alle ore 02:14 <technoboy85@xxxxxxxxx> ha scritto:
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -3052,6 +3052,12 @@ static int __init kfunc_init(void)
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &generic_kfunc_set);
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_STRUCT_OPS, &generic_kfunc_set);
> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL, &generic_kfunc_set);
> + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SKB, &generic_kfunc_set);
> + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCK, &generic_kfunc_set);
> + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_DEVICE, &generic_kfunc_set);
> + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCK_ADDR, &generic_kfunc_set);
> + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SYSCTL, &generic_kfunc_set);
> + ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_CGROUP_SOCKOPT, &generic_kfunc_set);
> ret = ret ?: register_btf_id_dtor_kfuncs(generic_dtors,
> ARRAY_SIZE(generic_dtors),
> THIS_MODULE);
This seems not enough, some kfuncs like bpf_cgroup_from_id are still rejected.
To fix this we need also this chunk:
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -8309,7 +8319,11 @@ static int bpf_prog_type_to_kfunc_hook(enum
bpf_prog_type prog_type)
case BPF_PROG_TYPE_SYSCALL:
return BTF_KFUNC_HOOK_SYSCALL;
case BPF_PROG_TYPE_CGROUP_SKB:
+ case BPF_PROG_TYPE_CGROUP_SOCK:
+ case BPF_PROG_TYPE_CGROUP_DEVICE:
case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
+ case BPF_PROG_TYPE_CGROUP_SYSCTL:
+ case BPF_PROG_TYPE_CGROUP_SOCKOPT:
return BTF_KFUNC_HOOK_CGROUP_SKB;
case BPF_PROG_TYPE_SCHED_ACT:
return BTF_KFUNC_HOOK_SCHED_ACT;
but even with this it won't work, because
bpf_prog_type_to_kfunc_hook() aliases many program types with a single
hook, and btf_kfunc_id_set_contains() will fail to check if the kfunc
is in the set.
One solution could be to extend the btf_kfunc_hook enum with an entry
for every CGROUP program type, but a thing I wanted to avoid is to let
this enum proliferate in this way.
I wish to group all the CGROUP_ program types into a single hook, and
perhaps drop the "SKB" in "BTF_KFUNC_HOOK_CGROUP_SKB" which will have
no meaning anymore.
Ideas?
--
Matteo Croce
perl -e 'for($t=0;;$t++){print chr($t*($t>>8|$t>>13)&255)}' |aplay
