From: Quentin Monnet Date: Sun, 7 Oct 2018 11:56:49 +0000 (+0100) Subject: nfp: bpf: copy eBPF subprograms information from kernel verifier X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c5da54d93eb43461a5b79e1fdad8409abad83a77;p=linux.git nfp: bpf: copy eBPF subprograms information from kernel verifier In order to support BPF-to-BPF calls in offloaded programs, the nfp driver must collect information about the distinct subprograms: namely, the number of subprograms composing the complete program and the stack depth of those subprograms. The latter in particular is non-trivial to collect, so we copy those elements from the kernel verifier via the newly added post-verification hook. The struct nfp_prog is extended to store this information. Stack depths are stored in an array of dedicated structs. Subprogram start indexes are not collected. Instead, meta instructions associated to the start of a subprogram will be marked with a flag in a later patch. Signed-off-by: Quentin Monnet Reviewed-by: Jiong Wang Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index 7050535383b84..7f6e850e42da7 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -423,6 +423,14 @@ static inline bool is_mbpf_div(const struct nfp_insn_meta *meta) return is_mbpf_alu(meta) && mbpf_op(meta) == BPF_DIV; } +/** + * struct nfp_bpf_subprog_info - nfp BPF sub-program (a.k.a. function) info + * @stack_depth: maximum stack depth used by this sub-program + */ +struct nfp_bpf_subprog_info { + u16 stack_depth; +}; + /** * struct nfp_prog - nfp BPF program * @bpf: backpointer to the bpf app priv structure @@ -439,7 +447,9 @@ static inline bool is_mbpf_div(const struct nfp_insn_meta *meta) * @stack_frame_depth: max stack depth for current frame * @adjust_head_location: if program has single adjust head call - the insn no. * @map_records_cnt: the number of map pointers recorded for this prog + * @subprog_cnt: number of sub-programs, including main function * @map_records: the map record pointers from bpf->maps_neutral + * @subprog: pointer to an array of objects holding info about sub-programs * @insns: list of BPF instruction wrappers (struct nfp_insn_meta) */ struct nfp_prog { @@ -464,7 +474,9 @@ struct nfp_prog { unsigned int adjust_head_location; unsigned int map_records_cnt; + unsigned int subprog_cnt; struct nfp_bpf_neutral_map **map_records; + struct nfp_bpf_subprog_info *subprog; struct list_head insns; }; diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c index c9519bb00f8a3..b683b03efd227 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c @@ -208,6 +208,8 @@ static void nfp_prog_free(struct nfp_prog *nfp_prog) { struct nfp_insn_meta *meta, *tmp; + kfree(nfp_prog->subprog); + list_for_each_entry_safe(meta, tmp, &nfp_prog->insns, l) { list_del(&meta->l); kfree(meta); diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index e470489021e3e..9ef74bc1ec1d7 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -642,6 +642,21 @@ nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) static int nfp_bpf_finalize(struct bpf_verifier_env *env) { + struct bpf_subprog_info *info; + struct nfp_prog *nfp_prog; + int i; + + nfp_prog = env->prog->aux->offload->dev_priv; + nfp_prog->subprog_cnt = env->subprog_cnt; + nfp_prog->subprog = kcalloc(nfp_prog->subprog_cnt, + sizeof(nfp_prog->subprog[0]), GFP_KERNEL); + if (!nfp_prog->subprog) + return -ENOMEM; + + info = env->subprog_info; + for (i = 0; i < nfp_prog->subprog_cnt; i++) + nfp_prog->subprog[i].stack_depth = info[i].stack_depth; + return 0; }