diff options
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/bpf/offload.c | 8 | ||||
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/bpf/verifier.c | 68 |
2 files changed, 68 insertions, 8 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c index 2ebd13b29c97..49c7bead8113 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c @@ -252,17 +252,9 @@ err_free: static int nfp_bpf_translate(struct nfp_net *nn, struct bpf_prog *prog) { struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv; - unsigned int stack_size; unsigned int max_instr; int err; - stack_size = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64; - if (prog->aux->stack_depth > stack_size) { - nn_info(nn, "stack too large: program %dB > FW stack %dB\n", - prog->aux->stack_depth, stack_size); - return -EOPNOTSUPP; - } - max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN); nfp_prog->__prog_alloc_len = max_instr * sizeof(u64); diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index cc1b2c601f4e..81a463726d55 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -34,10 +34,12 @@ #include <linux/bpf.h> #include <linux/bpf_verifier.h> #include <linux/kernel.h> +#include <linux/netdevice.h> #include <linux/pkt_cls.h> #include "../nfp_app.h" #include "../nfp_main.h" +#include "../nfp_net.h" #include "fw.h" #include "main.h" @@ -662,10 +664,67 @@ nfp_assign_subprog_idx(struct bpf_verifier_env *env, struct nfp_prog *nfp_prog) return 0; } +static unsigned int +nfp_bpf_get_stack_usage(struct nfp_prog *nfp_prog, unsigned int cnt) +{ + struct nfp_insn_meta *meta = nfp_prog_first_meta(nfp_prog); + unsigned int max_depth = 0, depth = 0, frame = 0; + struct nfp_insn_meta *ret_insn[MAX_CALL_FRAMES]; + unsigned short frame_depths[MAX_CALL_FRAMES]; + unsigned short ret_prog[MAX_CALL_FRAMES]; + unsigned short idx = meta->subprog_idx; + + /* Inspired from check_max_stack_depth() from kernel verifier. + * Starting from main subprogram, walk all instructions and recursively + * walk all callees that given subprogram can call. Since recursion is + * prevented by the kernel verifier, this algorithm only needs a local + * stack of MAX_CALL_FRAMES to remember callsites. + */ +process_subprog: + frame_depths[frame] = nfp_prog->subprog[idx].stack_depth; + frame_depths[frame] = round_up(frame_depths[frame], STACK_FRAME_ALIGN); + depth += frame_depths[frame]; + max_depth = max(max_depth, depth); + +continue_subprog: + for (; meta != nfp_prog_last_meta(nfp_prog) && meta->subprog_idx == idx; + meta = nfp_meta_next(meta)) { + if (!is_mbpf_pseudo_call(meta)) + continue; + + /* We found a call to a subprogram. Remember instruction to + * return to and subprog id. + */ + ret_insn[frame] = nfp_meta_next(meta); + ret_prog[frame] = idx; + + /* Find the callee and start processing it. */ + meta = nfp_bpf_goto_meta(nfp_prog, meta, + meta->n + 1 + meta->insn.imm, cnt); + idx = meta->subprog_idx; + frame++; + goto process_subprog; + } + /* End of for() loop means the last instruction of the subprog was + * reached. If we popped all stack frames, return; otherwise, go on + * processing remaining instructions from the caller. + */ + if (frame == 0) + return max_depth; + + depth -= frame_depths[frame]; + frame--; + meta = ret_insn[frame]; + idx = ret_prog[frame]; + goto continue_subprog; +} + static int nfp_bpf_finalize(struct bpf_verifier_env *env) { + unsigned int stack_size, stack_needed; struct bpf_subprog_info *info; struct nfp_prog *nfp_prog; + struct nfp_net *nn; int i; nfp_prog = env->prog->aux->offload->dev_priv; @@ -690,6 +749,15 @@ static int nfp_bpf_finalize(struct bpf_verifier_env *env) nfp_prog->subprog[i].stack_depth += BPF_REG_SIZE * 4; } + nn = netdev_priv(env->prog->aux->offload->netdev); + stack_size = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64; + stack_needed = nfp_bpf_get_stack_usage(nfp_prog, env->prog->len); + if (stack_needed > stack_size) { + pr_vlog(env, "stack too large: program %dB > FW stack %dB\n", + stack_needed, stack_size); + return -EOPNOTSUPP; + } + return 0; } |