diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h index dbd00982fd2b698bfa5bedc1572583890e75fe63..2134045e14c36a88c51717b7f4b36f07bbaa5c83 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/main.h +++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h @@ -206,6 +206,11 @@ enum nfp_bpf_map_use { NFP_MAP_USE_ATOMIC_CNT, }; +struct nfp_bpf_map_word { + unsigned char type :4; + unsigned char non_zero_update :1; +}; + /** * struct nfp_bpf_map - private per-map data attached to BPF maps for offload * @offmap: pointer to the offloaded BPF map @@ -219,7 +224,7 @@ struct nfp_bpf_map { struct nfp_app_bpf *bpf; u32 tid; struct list_head l; - enum nfp_bpf_map_use use_map[]; + struct nfp_bpf_map_word use_map[]; }; struct nfp_bpf_neutral_map { diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c index 1ccd6371a15b5c3c0a142909d63b4e0796418fd4..6140e4650b71cc249d82f84fefc1fda1efe26b56 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c @@ -299,10 +299,25 @@ static void nfp_map_bpf_byte_swap(struct nfp_bpf_map *nfp_map, void *value) unsigned int i; for (i = 0; i < DIV_ROUND_UP(nfp_map->offmap->map.value_size, 4); i++) - if (nfp_map->use_map[i] == NFP_MAP_USE_ATOMIC_CNT) + if (nfp_map->use_map[i].type == NFP_MAP_USE_ATOMIC_CNT) word[i] = (__force u32)cpu_to_be32(word[i]); } +/* Mark value as unsafely initialized in case it becomes atomic later + * and we didn't byte swap something non-byte swap neutral. + */ +static void +nfp_map_bpf_byte_swap_record(struct nfp_bpf_map *nfp_map, void *value) +{ + u32 *word = value; + unsigned int i; + + for (i = 0; i < DIV_ROUND_UP(nfp_map->offmap->map.value_size, 4); i++) + if (nfp_map->use_map[i].type == NFP_MAP_UNUSED && + word[i] != (__force u32)cpu_to_be32(word[i])) + nfp_map->use_map[i].non_zero_update = 1; +} + static int nfp_bpf_map_lookup_entry(struct bpf_offloaded_map *offmap, void *key, void *value) @@ -322,6 +337,7 @@ nfp_bpf_map_update_entry(struct bpf_offloaded_map *offmap, void *key, void *value, u64 flags) { nfp_map_bpf_byte_swap(offmap->dev_priv, value); + nfp_map_bpf_byte_swap_record(offmap->dev_priv, value); return nfp_bpf_ctrl_update_entry(offmap, key, value, flags); } diff --git a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c index a6e9248669e141d4d19f0536eed52adf6ef78d90..db7e186dae56d4c0dda0d3ba59c5408867ef7371 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/verifier.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/verifier.c @@ -108,6 +108,46 @@ nfp_record_adjust_head(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog, 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, @@ -198,7 +238,8 @@ nfp_bpf_check_call(struct nfp_prog *nfp_prog, struct bpf_verifier_env *env, 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_stack_arg_ok("map_update", env, reg3, NULL) || + !nfp_bpf_map_update_value_ok(env)) return -EOPNOTSUPP; break; @@ -376,15 +417,22 @@ 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] != NFP_MAP_UNUSED && - nfp_map->use_map[off / 4] != 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]), + nfp_bpf_map_use_name(nfp_map->use_map[off / 4].type), nfp_bpf_map_use_name(use), off); return -EOPNOTSUPP; } - nfp_map->use_map[off / 4] = use; + 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; }