Re: [PATCH v2] bpf: restore the ebpf program ID for BPF_AUDIT_UNLOAD and PERF_BPF_EVENT_PROG_UNLOAD

On Fri, Dec 23, 2022 at 01:55:31PM -0500, Paul Moore wrote: SNIP > diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c > index 50854265864d..2795f03f5f34 100644 > --- a/drivers/net/netdevsim/bpf.c > +++ b/drivers/net/netdevsim/bpf.c > @@ -109,7 +109,7 @@ nsim_bpf_offload(struct netdevsim *ns, struct bpf_prog > *prog, bool oldprog) > "bad offload state, expected offload %sto be active", > oldprog ? "" : "not "); > ns->bpf_offloaded = prog; > - ns->bpf_offloaded_id = prog ? prog->aux->id : 0; > + ns->bpf_offloaded_id = prog ? bpf_prog_get_id(prog) : 0; > nsim_prog_set_loaded(prog, true); > > return 0; > @@ -221,6 +221,7 @@ static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev, > struct nsim_bpf_bound_prog *state; > char name[16]; > int ret; > + u32 id; > > state = kzalloc(sizeof(*state), GFP_KERNEL); > if (!state) > @@ -239,7 +240,8 @@ static int nsim_bpf_create_prog(struct nsim_dev *nsim_dev, > return ret; > } > > - debugfs_create_u32("id", 0400, state->ddir, &prog->aux->id); > + id = bpf_prog_get_id(prog); > + debugfs_create_u32("id", 0400, state->ddir, &id); > debugfs_create_file("state", 0400, state->ddir, > &state->state, &nsim_bpf_string_fops); > debugfs_create_bool("loaded", 0400, state->ddir, &state->is_loaded); > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index 9e7d46d16032..18e965bd7db9 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -1102,7 +1102,7 @@ struct bpf_prog_aux { > u32 max_pkt_offset; > u32 max_tp_access; > u32 stack_depth; > - u32 id; > + u32 __id; /* access via bpf_prog_get_id() to check bpf_prog::valid_id */ it breaks bpftool that uses BPF_CORE_READ((struct bpf_prog *)ent, aux, id); and bpffs selftest because of preload iter object uses aux->id kernel/bpf/preload/iterators/iterators.bpf.c it'd be great to have a solution that keep 'id' field, because it's probably used in many bpf programs already jirka > u32 func_cnt; /* used by non-func prog as the number of func progs */ > u32 func_idx; /* 0 for non-func prog, the index in func array for func prog */ > u32 attach_btf_id; /* in-kernel BTF type id to attach to */ > @@ -1197,7 +1197,8 @@ struct bpf_prog { > enforce_expected_attach_type:1, /* Enforce expected_attach_type checking at > attach time */ > call_get_stack:1, /* Do we call bpf_get_stack() or bpf_get_stackid() */ > call_get_func_ip:1, /* Do we call get_func_ip() */ > - tstamp_type_access:1; /* Accessed __sk_buff->tstamp_type */ > + tstamp_type_access:1, /* Accessed __sk_buff->tstamp_type */ > + valid_id:1; /* Is bpf_prog::aux::__id valid? */ > enum bpf_prog_type type; /* Type of BPF program */ > enum bpf_attach_type expected_attach_type; /* For some prog types */ > u32 len; /* Number of filter blocks */ > @@ -1688,6 +1689,12 @@ void bpf_prog_inc(struct bpf_prog *prog); > struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog); > void bpf_prog_put(struct bpf_prog *prog); SNIP