static int nfp_bpf_check_exit(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env) { const struct bpf_reg_state *reg0 = cur_regs(env) + BPF_REG_0; u64 imm; if (nfp_prog->type == BPF_PROG_TYPE_XDP) return 0; if (!(reg0->type == SCALAR_VALUE && tnum_is_const(reg0->var_off))) { char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg0->var_off); pr_vlog(env, "unsupported exit state: %d, var_off: %s\n", reg0->type, tn_buf); return -EINVAL; } imm = reg0->var_off.value; if (nfp_prog->type == BPF_PROG_TYPE_SCHED_CLS && imm <= TC_ACT_REDIRECT && imm != TC_ACT_SHOT && imm != TC_ACT_STOLEN && imm != TC_ACT_QUEUED) { pr_vlog(env, "unsupported exit state: %d, imm: %llx\n", reg0->type, imm); return -EINVAL; } return 0; }
static int nfp_bpf_check_ptr(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, struct bpf_verifier_env *env, u8 reg_no) { const struct bpf_reg_state *reg = cur_regs(env) + reg_no; int err; if (reg->type != PTR_TO_CTX && reg->type != PTR_TO_STACK && reg->type != PTR_TO_MAP_VALUE && reg->type != PTR_TO_PACKET) { pr_vlog(env, "unsupported ptr type: %d\n", reg->type); return -EINVAL; } if (reg->type == PTR_TO_STACK) { err = nfp_bpf_check_stack_access(nfp_prog, meta, reg, env); if (err) return err; } if (reg->type == PTR_TO_MAP_VALUE) { if (is_mbpf_load(meta)) { err = nfp_bpf_map_mark_used(env, meta, reg, NFP_MAP_USE_READ); if (err) return err; } if (is_mbpf_store(meta)) { pr_vlog(env, "map writes not supported\n"); return -EOPNOTSUPP; } if (is_mbpf_xadd(meta)) { err = nfp_bpf_map_mark_used(env, meta, reg, NFP_MAP_USE_ATOMIC_CNT); if (err) return err; } } if (meta->ptr.type != NOT_INIT && meta->ptr.type != reg->type) { pr_vlog(env, "ptr type changed for instruction %d -> %d\n", meta->ptr.type, reg->type); return -EINVAL; } meta->ptr = *reg; return 0; }
static int nfp_bpf_check_xadd(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, struct bpf_verifier_env *env) { const struct bpf_reg_state *sreg = cur_regs(env) + meta->insn.src_reg; const struct bpf_reg_state *dreg = cur_regs(env) + meta->insn.dst_reg; if (dreg->type != PTR_TO_MAP_VALUE) { pr_vlog(env, "atomic add not to a map value pointer: %d\n", dreg->type); return -EOPNOTSUPP; } if (sreg->type != SCALAR_VALUE) { pr_vlog(env, "atomic add not of a scalar: %d\n", sreg->type); return -EOPNOTSUPP; } meta->xadd_over_16bit |= sreg->var_off.value > 0xffff || sreg->var_off.mask > 0xffff; meta->xadd_maybe_16bit |= (sreg->var_off.value & ~sreg->var_off.mask) <= 0xffff; return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg); }
static int nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx) { struct nfp_prog *nfp_prog = env->prog->aux->offload->dev_priv; struct nfp_insn_meta *meta = nfp_prog->verifier_meta; meta = nfp_bpf_goto_meta(nfp_prog, meta, insn_idx, env->prog->len); nfp_prog->verifier_meta = meta; if (!nfp_bpf_supported_opcode(meta->insn.code)) { pr_vlog(env, "instruction %#02x not supported\n", meta->insn.code); return -EINVAL; } if (meta->insn.src_reg >= MAX_BPF_REG || meta->insn.dst_reg >= MAX_BPF_REG) { pr_vlog(env, "program uses extended registers - jit hardening?\n"); return -EINVAL; } if (meta->insn.code == (BPF_JMP | BPF_CALL)) return nfp_bpf_check_call(nfp_prog, env, meta); if (meta->insn.code == (BPF_JMP | BPF_EXIT)) return nfp_bpf_check_exit(nfp_prog, env); if (is_mbpf_load(meta)) return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.src_reg); if (is_mbpf_store(meta)) return nfp_bpf_check_store(nfp_prog, meta, env); if (is_mbpf_xadd(meta)) return nfp_bpf_check_xadd(nfp_prog, meta, env); if (is_mbpf_indir_shift(meta)) { const struct bpf_reg_state *sreg = cur_regs(env) + meta->insn.src_reg; meta->umin = min(meta->umin, sreg->umin_value); meta->umax = max(meta->umax, sreg->umax_value); } return 0; }
static int nfp_bpf_check_store(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, struct bpf_verifier_env *env) { const struct bpf_reg_state *reg = cur_regs(env) + meta->insn.dst_reg; if (reg->type == PTR_TO_CTX) { if (nfp_prog->type == BPF_PROG_TYPE_XDP) { /* XDP ctx accesses must be 4B in size */ switch (meta->insn.off) { case offsetof(struct xdp_md, rx_queue_index): if (nfp_prog->bpf->queue_select) goto exit_check_ptr; pr_vlog(env, "queue selection not supported by FW\n"); return -EOPNOTSUPP; } } pr_vlog(env, "unsupported store to context field\n"); return -EOPNOTSUPP; } exit_check_ptr: return nfp_bpf_check_ptr(nfp_prog, meta, env, meta->insn.dst_reg); }
static int nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env, struct nfp_insn_meta *meta) { const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1; const struct bpf_reg_state *reg2 = cur_regs(env) + BPF_REG_2; const struct bpf_reg_state *reg3 = cur_regs(env) + BPF_REG_3; struct nfp_app_bpf *bpf = nfp_prog->bpf; u32 func_id = meta->insn.imm; switch (func_id) { case BPF_FUNC_xdp_adjust_head: if (!bpf->adjust_head.off_max) { pr_vlog(env, "adjust_head not supported by FW\n"); return -EOPNOTSUPP; } if (!(bpf->adjust_head.flags & NFP_BPF_ADJUST_HEAD_NO_META)) { pr_vlog(env, "adjust_head: FW requires shifting metadata, not supported by the driver\n"); return -EOPNOTSUPP; } nfp_record_adjust_head(bpf, nfp_prog, meta, reg2); break; case BPF_FUNC_map_lookup_elem: if (!nfp_bpf_map_call_ok("map_lookup", env, meta, bpf->helpers.map_lookup, reg1) || !nfp_bpf_stack_arg_ok("map_lookup", env, reg2, meta->func_id ? &meta->arg2 : NULL)) return -EOPNOTSUPP; break; case BPF_FUNC_map_update_elem: if (!nfp_bpf_map_call_ok("map_update", env, meta, bpf->helpers.map_update, reg1) || !nfp_bpf_stack_arg_ok("map_update", env, reg2, meta->func_id ? &meta->arg2 : NULL) || !nfp_bpf_stack_arg_ok("map_update", env, reg3, NULL)) return -EOPNOTSUPP; break; case BPF_FUNC_map_delete_elem: if (!nfp_bpf_map_call_ok("map_delete", env, meta, bpf->helpers.map_delete, reg1) || !nfp_bpf_stack_arg_ok("map_delete", env, reg2, meta->func_id ? &meta->arg2 : NULL)) return -EOPNOTSUPP; break; case BPF_FUNC_get_prandom_u32: if (bpf->pseudo_random) break; pr_vlog(env, "bpf_get_prandom_u32(): FW doesn't support random number generation\n"); return -EOPNOTSUPP; case BPF_FUNC_perf_event_output: BUILD_BUG_ON(NFP_BPF_SCALAR_VALUE != SCALAR_VALUE || NFP_BPF_MAP_VALUE != PTR_TO_MAP_VALUE || NFP_BPF_STACK != PTR_TO_STACK || NFP_BPF_PACKET_DATA != PTR_TO_PACKET); if (!bpf->helpers.perf_event_output) { pr_vlog(env, "event_output: not supported by FW\n"); return -EOPNOTSUPP; } /* Force current CPU to make sure we can report the event * wherever we get the control message from FW. */ if (reg3->var_off.mask & BPF_F_INDEX_MASK || (reg3->var_off.value & BPF_F_INDEX_MASK) != BPF_F_CURRENT_CPU) { char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg3->var_off); pr_vlog(env, "event_output: must use BPF_F_CURRENT_CPU, var_off: %s\n", tn_buf); return -EOPNOTSUPP; } /* Save space in meta, we don't care about arguments other * than 4th meta, shove it into arg1. */ reg1 = cur_regs(env) + BPF_REG_4; if (reg1->type != SCALAR_VALUE /* NULL ptr */ && reg1->type != PTR_TO_STACK && reg1->type != PTR_TO_MAP_VALUE && reg1->type != PTR_TO_PACKET) { pr_vlog(env, "event_output: unsupported ptr type: %d\n", reg1->type); return -EOPNOTSUPP; } if (reg1->type == PTR_TO_STACK && !nfp_bpf_stack_arg_ok("event_output", env, reg1, NULL)) return -EOPNOTSUPP; /* Warn user that on offload NFP may return success even if map * is not going to accept the event, since the event output is * fully async and device won't know the state of the map. * There is also FW limitation on the event length. * * Lost events will not show up on the perf ring, driver * won't see them at all. Events may also get reordered. */ dev_warn_once(&nfp_prog->bpf->app->pf->pdev->dev, "bpf: note: return codes and behavior of bpf_event_output() helper differs for offloaded programs!\n"); pr_vlog(env, "warning: return codes and behavior of event_output helper differ for offload!\n"); if (!meta->func_id) break; if (reg1->type != meta->arg1.type) { pr_vlog(env, "event_output: ptr type changed: %d %d\n", meta->arg1.type, reg1->type); return -EINVAL; } break; default: pr_vlog(env, "unsupported function id: %d\n", func_id); return -EOPNOTSUPP; } meta->func_id = func_id; meta->arg1 = *reg1; meta->arg2.reg = *reg2; return 0; }
static int nfp_bpf_check_alu(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, struct bpf_verifier_env *env) { const struct bpf_reg_state *sreg = cur_regs(env) + meta->insn.src_reg; const struct bpf_reg_state *dreg = cur_regs(env) + meta->insn.dst_reg; meta->umin_src = min(meta->umin_src, sreg->umin_value); meta->umax_src = max(meta->umax_src, sreg->umax_value); meta->umin_dst = min(meta->umin_dst, dreg->umin_value); meta->umax_dst = max(meta->umax_dst, dreg->umax_value); /* NFP supports u16 and u32 multiplication. * * For ALU64, if either operand is beyond u32's value range, we reject * it. One thing to note, if the source operand is BPF_K, then we need * to check "imm" field directly, and we'd reject it if it is negative. * Because for ALU64, "imm" (with s32 type) is expected to be sign * extended to s64 which NFP mul doesn't support. * * For ALU32, it is fine for "imm" be negative though, because the * result is 32-bits and there is no difference on the low halve of * the result for signed/unsigned mul, so we will get correct result. */ if (is_mbpf_mul(meta)) { if (meta->umax_dst > U32_MAX) { pr_vlog(env, "multiplier is not within u32 value range\n"); return -EINVAL; } if (mbpf_src(meta) == BPF_X && meta->umax_src > U32_MAX) { pr_vlog(env, "multiplicand is not within u32 value range\n"); return -EINVAL; } if (mbpf_class(meta) == BPF_ALU64 && mbpf_src(meta) == BPF_K && meta->insn.imm < 0) { pr_vlog(env, "sign extended multiplicand won't be within u32 value range\n"); return -EINVAL; } } /* NFP doesn't have divide instructions, we support divide by constant * through reciprocal multiplication. Given NFP support multiplication * no bigger than u32, we'd require divisor and dividend no bigger than * that as well. * * Also eBPF doesn't support signed divide and has enforced this on C * language level by failing compilation. However LLVM assembler hasn't * enforced this, so it is possible for negative constant to leak in as * a BPF_K operand through assembly code, we reject such cases as well. */ if (is_mbpf_div(meta)) { if (meta->umax_dst > U32_MAX) { pr_vlog(env, "dividend is not within u32 value range\n"); return -EINVAL; } if (mbpf_src(meta) == BPF_X) { if (meta->umin_src != meta->umax_src) { pr_vlog(env, "divisor is not constant\n"); return -EINVAL; } if (meta->umax_src > U32_MAX) { pr_vlog(env, "divisor is not within u32 value range\n"); return -EINVAL; } } if (mbpf_src(meta) == BPF_K && meta->insn.imm < 0) { pr_vlog(env, "divide by negative constant is not supported\n"); return -EINVAL; } } return 0; }
static int nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env, struct nfp_insn_meta *meta) { const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1; const struct bpf_reg_state *reg2 = cur_regs(env) + BPF_REG_2; struct nfp_app_bpf *bpf = nfp_prog->bpf; u32 func_id = meta->insn.imm; s64 off, old_off; switch (func_id) { case BPF_FUNC_xdp_adjust_head: if (!bpf->adjust_head.off_max) { pr_vlog(env, "adjust_head not supported by FW\n"); return -EOPNOTSUPP; } if (!(bpf->adjust_head.flags & NFP_BPF_ADJUST_HEAD_NO_META)) { pr_vlog(env, "adjust_head: FW requires shifting metadata, not supported by the driver\n"); return -EOPNOTSUPP; } nfp_record_adjust_head(bpf, nfp_prog, meta, reg2); break; case BPF_FUNC_map_lookup_elem: if (!bpf->helpers.map_lookup) { pr_vlog(env, "map_lookup: not supported by FW\n"); return -EOPNOTSUPP; } if (reg2->type != PTR_TO_STACK) { pr_vlog(env, "map_lookup: unsupported key ptr type %d\n", reg2->type); return -EOPNOTSUPP; } if (!tnum_is_const(reg2->var_off)) { pr_vlog(env, "map_lookup: variable key pointer\n"); return -EOPNOTSUPP; } off = reg2->var_off.value + reg2->off; if (-off % 4) { pr_vlog(env, "map_lookup: unaligned stack pointer %lld\n", -off); return -EOPNOTSUPP; } /* Rest of the checks is only if we re-parse the same insn */ if (!meta->func_id) break; old_off = meta->arg2.var_off.value + meta->arg2.off; meta->arg2_var_off |= off != old_off; if (meta->arg1.map_ptr != reg1->map_ptr) { pr_vlog(env, "map_lookup: called for different map\n"); return -EOPNOTSUPP; } break; default: pr_vlog(env, "unsupported function id: %d\n", func_id); return -EOPNOTSUPP; } meta->func_id = func_id; meta->arg1 = *reg1; meta->arg2 = *reg2; return 0; }