| /* |
| * Copyright (C) 2016-2018 Netronome Systems, Inc. |
| * |
| * This software is dual licensed under the GNU General License Version 2, |
| * June 1991 as shown in the file COPYING in the top-level directory of this |
| * source tree or the BSD 2-Clause License provided below. You have the |
| * option to license this software under the complete terms of either license. |
| * |
| * The BSD 2-Clause License: |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials |
| * provided with the distribution. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS |
| * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN |
| * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
| * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| */ |
| |
| #include <linux/bpf.h> |
| #include <linux/bpf_verifier.h> |
| #include <linux/kernel.h> |
| #include <linux/pkt_cls.h> |
| |
| #include "../nfp_app.h" |
| #include "../nfp_main.h" |
| #include "fw.h" |
| #include "main.h" |
| |
| #define pr_vlog(env, fmt, ...) \ |
| bpf_verifier_log_write(env, "[nfp] " fmt, ##__VA_ARGS__) |
| |
| struct nfp_insn_meta * |
| nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, |
| unsigned int insn_idx, unsigned int n_insns) |
| { |
| unsigned int forward, backward, i; |
| |
| backward = meta->n - insn_idx; |
| forward = insn_idx - meta->n; |
| |
| if (min(forward, backward) > n_insns - insn_idx - 1) { |
| backward = n_insns - insn_idx - 1; |
| meta = nfp_prog_last_meta(nfp_prog); |
| } |
| if (min(forward, backward) > insn_idx && backward > insn_idx) { |
| forward = insn_idx; |
| meta = nfp_prog_first_meta(nfp_prog); |
| } |
| |
| if (forward < backward) |
| for (i = 0; i < forward; i++) |
| meta = nfp_meta_next(meta); |
| else |
| for (i = 0; i < backward; i++) |
| meta = nfp_meta_prev(meta); |
| |
| return meta; |
| } |
| |
| static void |
| nfp_record_adjust_head(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog, |
| struct nfp_insn_meta *meta, |
| const struct bpf_reg_state *reg2) |
| { |
| unsigned int location = UINT_MAX; |
| int imm; |
| |
| /* Datapath usually can give us guarantees on how much adjust head |
| * can be done without the need for any checks. Optimize the simple |
| * case where there is only one adjust head by a constant. |
| */ |
| if (reg2->type != SCALAR_VALUE || !tnum_is_const(reg2->var_off)) |
| goto exit_set_location; |
| imm = reg2->var_off.value; |
| /* Translator will skip all checks, we need to guarantee min pkt len */ |
| if (imm > ETH_ZLEN - ETH_HLEN) |
| goto exit_set_location; |
| if (imm > (int)bpf->adjust_head.guaranteed_add || |
| imm < -bpf->adjust_head.guaranteed_sub) |
| goto exit_set_location; |
| |
| if (nfp_prog->adjust_head_location) { |
| /* Only one call per program allowed */ |
| if (nfp_prog->adjust_head_location != meta->n) |
| goto exit_set_location; |
| |
| if (meta->arg2.reg.var_off.value != imm) |
| goto exit_set_location; |
| } |
| |
| location = meta->n; |
| exit_set_location: |
| nfp_prog->adjust_head_location = location; |
| } |
| |
| static bool nfp_bpf_map_update_value_ok(struct bpf_verifier_env *env) |
| { |
| const struct bpf_reg_state *reg1 = cur_regs(env) + BPF_REG_1; |
| const struct bpf_reg_state *reg3 = cur_regs(env) + BPF_REG_3; |
| struct bpf_offloaded_map *offmap; |
| struct bpf_func_state *state; |
| struct nfp_bpf_map *nfp_map; |
| int off, i; |
| |
| state = env->cur_state->frame[reg3->frameno]; |
| |
| /* We need to record each time update happens with non-zero words, |
| * in case such word is used in atomic operations. |
| * Implicitly depend on nfp_bpf_stack_arg_ok(reg3) being run before. |
| */ |
| |
| offmap = map_to_offmap(reg1->map_ptr); |
| nfp_map = offmap->dev_priv; |
| off = reg3->off + reg3->var_off.value; |
| |
| for (i = 0; i < offmap->map.value_size; i++) { |
| struct bpf_stack_state *stack_entry; |
| unsigned int soff; |
| |
| soff = -(off + i) - 1; |
| stack_entry = &state->stack[soff / BPF_REG_SIZE]; |
| if (stack_entry->slot_type[soff % BPF_REG_SIZE] == STACK_ZERO) |
| continue; |
| |
| if (nfp_map->use_map[i / 4].type == NFP_MAP_USE_ATOMIC_CNT) { |
| pr_vlog(env, "value at offset %d/%d may be non-zero, bpf_map_update_elem() is required to initialize atomic counters to zero to avoid offload endian issues\n", |
| i, soff); |
| return false; |
| } |
| nfp_map->use_map[i / 4].non_zero_update = 1; |
| } |
| |
| return true; |
| } |
| |
| static int |
| nfp_bpf_stack_arg_ok(const char *fname, struct bpf_verifier_env *env, |
| const struct bpf_reg_state *reg, |
| struct nfp_bpf_reg_state *old_arg) |
| { |
| s64 off, old_off; |
| |
| if (reg->type != PTR_TO_STACK) { |
| pr_vlog(env, "%s: unsupported ptr type %d\n", |
| fname, reg->type); |
| return false; |
| } |
| if (!tnum_is_const(reg->var_off)) { |
| pr_vlog(env, "%s: variable pointer\n", fname); |
| return false; |
| } |
| |
| off = reg->var_off.value + reg->off; |
| if (-off % 4) { |
| pr_vlog(env, "%s: unaligned stack pointer %lld\n", fname, -off); |
| return false; |
| } |
| |
| /* Rest of the checks is only if we re-parse the same insn */ |
| if (!old_arg) |
| return true; |
| |
| old_off = old_arg->reg.var_off.value + old_arg->reg.off; |
| old_arg->var_off |= off != old_off; |
| |
| return true; |
| } |
| |
| static bool |
| nfp_bpf_map_call_ok(const char *fname, struct bpf_verifier_env *env, |
| struct nfp_insn_meta *meta, |
| u32 helper_tgt, const struct bpf_reg_state *reg1) |
| { |
| if (!helper_tgt) { |
| pr_vlog(env, "%s: not supported by FW\n", fname); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| 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_xdp_adjust_tail: |
| if (!bpf->adjust_tail) { |
| pr_vlog(env, "adjust_tail not supported by FW\n"); |
| return -EOPNOTSUPP; |
| } |
| 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) || |
| !nfp_bpf_map_update_value_ok(env)) |
| 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_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_stack_access(struct nfp_prog *nfp_prog, |
| struct nfp_insn_meta *meta, |
| const struct bpf_reg_state *reg, |
| struct bpf_verifier_env *env) |
| { |
| s32 old_off, new_off; |
| |
| if (!tnum_is_const(reg->var_off)) { |
| pr_vlog(env, "variable ptr stack access\n"); |
| return -EINVAL; |
| } |
| |
| if (meta->ptr.type == NOT_INIT) |
| return 0; |
| |
| old_off = meta->ptr.off + meta->ptr.var_off.value; |
| new_off = reg->off + reg->var_off.value; |
| |
| meta->ptr_not_const |= old_off != new_off; |
| |
| if (!meta->ptr_not_const) |
| return 0; |
| |
| if (old_off % 4 == new_off % 4) |
| return 0; |
| |
| pr_vlog(env, "stack access changed location was:%d is:%d\n", |
| old_off, new_off); |
| return -EINVAL; |
| } |
| |
| static const char *nfp_bpf_map_use_name(enum nfp_bpf_map_use use) |
| { |
| static const char * const names[] = { |
| [NFP_MAP_UNUSED] = "unused", |
| [NFP_MAP_USE_READ] = "read", |
| [NFP_MAP_USE_WRITE] = "write", |
| [NFP_MAP_USE_ATOMIC_CNT] = "atomic", |
| }; |
| |
| if (use >= ARRAY_SIZE(names) || !names[use]) |
| return "unknown"; |
| return names[use]; |
| } |
| |
| static int |
| nfp_bpf_map_mark_used_one(struct bpf_verifier_env *env, |
| struct nfp_bpf_map *nfp_map, |
| unsigned int off, enum nfp_bpf_map_use use) |
| { |
| if (nfp_map->use_map[off / 4].type != NFP_MAP_UNUSED && |
| nfp_map->use_map[off / 4].type != use) { |
| pr_vlog(env, "map value use type conflict %s vs %s off: %u\n", |
| nfp_bpf_map_use_name(nfp_map->use_map[off / 4].type), |
| nfp_bpf_map_use_name(use), off); |
| return -EOPNOTSUPP; |
| } |
| |
| if (nfp_map->use_map[off / 4].non_zero_update && |
| use == NFP_MAP_USE_ATOMIC_CNT) { |
| pr_vlog(env, "atomic counter in map value may already be initialized to non-zero value off: %u\n", |
| off); |
| return -EOPNOTSUPP; |
| } |
| |
| nfp_map->use_map[off / 4].type = use; |
| |
| return 0; |
| } |
| |
| static int |
| nfp_bpf_map_mark_used(struct bpf_verifier_env *env, struct nfp_insn_meta *meta, |
| const struct bpf_reg_state *reg, |
| enum nfp_bpf_map_use use) |
| { |
| struct bpf_offloaded_map *offmap; |
| struct nfp_bpf_map *nfp_map; |
| unsigned int size, off; |
| int i, err; |
| |
| if (!tnum_is_const(reg->var_off)) { |
| pr_vlog(env, "map value offset is variable\n"); |
| return -EOPNOTSUPP; |
| } |
| |
| off = reg->var_off.value + meta->insn.off + reg->off; |
| size = BPF_LDST_BYTES(&meta->insn); |
| offmap = map_to_offmap(reg->map_ptr); |
| nfp_map = offmap->dev_priv; |
| |
| if (off + size > offmap->map.value_size) { |
| pr_vlog(env, "map value access out-of-bounds\n"); |
| return -EINVAL; |
| } |
| |
| for (i = 0; i < size; i += 4 - (off + i) % 4) { |
| err = nfp_bpf_map_mark_used_one(env, nfp_map, off + i, use); |
| if (err) |
| return err; |
| } |
| |
| 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_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_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_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_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_alu(meta)) |
| return nfp_bpf_check_alu(nfp_prog, meta, env); |
| |
| return 0; |
| } |
| |
| const struct bpf_prog_offload_ops nfp_bpf_analyzer_ops = { |
| .insn_hook = nfp_verify_insn, |
| }; |