bpf: Convert bpf_prog refcnt to atomic64_t
Similarly to bpf_map's refcnt/usercnt, convert bpf_prog's refcnt to atomic64 and remove artificial 32k limit. This allows to make bpf_prog's refcounting non-failing, simplifying logic of users of bpf_prog_add/bpf_prog_inc. Validated compilation by running allyesconfig kernel build. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191117172806.2195367-3-andriin@fb.com
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1e0bd5a091
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@ -3171,13 +3171,8 @@ static int bnxt_init_one_rx_ring(struct bnxt *bp, int ring_nr)
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bnxt_init_rxbd_pages(ring, type);
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if (BNXT_RX_PAGE_MODE(bp) && bp->xdp_prog) {
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rxr->xdp_prog = bpf_prog_add(bp->xdp_prog, 1);
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if (IS_ERR(rxr->xdp_prog)) {
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int rc = PTR_ERR(rxr->xdp_prog);
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rxr->xdp_prog = NULL;
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return rc;
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}
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bpf_prog_add(bp->xdp_prog, 1);
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rxr->xdp_prog = bp->xdp_prog;
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}
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prod = rxr->rx_prod;
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for (i = 0; i < bp->rx_ring_size; i++) {
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@ -1876,13 +1876,8 @@ static int nicvf_xdp_setup(struct nicvf *nic, struct bpf_prog *prog)
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if (nic->xdp_prog) {
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/* Attach BPF program */
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nic->xdp_prog = bpf_prog_add(nic->xdp_prog, nic->rx_queues - 1);
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if (!IS_ERR(nic->xdp_prog)) {
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bpf_attached = true;
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} else {
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ret = PTR_ERR(nic->xdp_prog);
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nic->xdp_prog = NULL;
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}
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bpf_prog_add(nic->xdp_prog, nic->rx_queues - 1);
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bpf_attached = true;
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}
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/* Calculate Tx queues needed for XDP and network stack */
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@ -1807,11 +1807,8 @@ static int setup_xdp(struct net_device *dev, struct bpf_prog *prog)
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if (prog && !xdp_mtu_valid(priv, dev->mtu))
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return -EINVAL;
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if (prog) {
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prog = bpf_prog_add(prog, priv->num_channels);
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if (IS_ERR(prog))
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return PTR_ERR(prog);
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}
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if (prog)
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bpf_prog_add(prog, priv->num_channels);
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up = netif_running(dev);
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need_update = (!!priv->xdp_prog != !!prog);
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@ -2286,11 +2286,7 @@ int mlx4_en_try_alloc_resources(struct mlx4_en_priv *priv,
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lockdep_is_held(&priv->mdev->state_lock));
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if (xdp_prog && carry_xdp_prog) {
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xdp_prog = bpf_prog_add(xdp_prog, tmp->rx_ring_num);
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if (IS_ERR(xdp_prog)) {
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mlx4_en_free_resources(tmp);
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return PTR_ERR(xdp_prog);
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}
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bpf_prog_add(xdp_prog, tmp->rx_ring_num);
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for (i = 0; i < tmp->rx_ring_num; i++)
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rcu_assign_pointer(tmp->rx_ring[i]->xdp_prog,
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xdp_prog);
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@ -2782,11 +2778,9 @@ static int mlx4_xdp_set(struct net_device *dev, struct bpf_prog *prog)
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* program for a new one.
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*/
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if (priv->tx_ring_num[TX_XDP] == xdp_ring_num) {
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if (prog) {
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prog = bpf_prog_add(prog, priv->rx_ring_num - 1);
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if (IS_ERR(prog))
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return PTR_ERR(prog);
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}
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if (prog)
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bpf_prog_add(prog, priv->rx_ring_num - 1);
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mutex_lock(&mdev->state_lock);
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for (i = 0; i < priv->rx_ring_num; i++) {
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old_prog = rcu_dereference_protected(
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@ -2807,13 +2801,8 @@ static int mlx4_xdp_set(struct net_device *dev, struct bpf_prog *prog)
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if (!tmp)
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return -ENOMEM;
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if (prog) {
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prog = bpf_prog_add(prog, priv->rx_ring_num - 1);
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if (IS_ERR(prog)) {
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err = PTR_ERR(prog);
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goto out;
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}
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}
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if (prog)
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bpf_prog_add(prog, priv->rx_ring_num - 1);
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mutex_lock(&mdev->state_lock);
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memcpy(&new_prof, priv->prof, sizeof(struct mlx4_en_port_profile));
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@ -2862,7 +2851,6 @@ static int mlx4_xdp_set(struct net_device *dev, struct bpf_prog *prog)
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unlock_out:
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mutex_unlock(&mdev->state_lock);
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out:
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kfree(tmp);
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return err;
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}
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@ -408,12 +408,9 @@ static int mlx5e_alloc_rq(struct mlx5e_channel *c,
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rq->stats = &c->priv->channel_stats[c->ix].rq;
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INIT_WORK(&rq->recover_work, mlx5e_rq_err_cqe_work);
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rq->xdp_prog = params->xdp_prog ? bpf_prog_inc(params->xdp_prog) : NULL;
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if (IS_ERR(rq->xdp_prog)) {
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err = PTR_ERR(rq->xdp_prog);
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rq->xdp_prog = NULL;
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goto err_rq_wq_destroy;
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}
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if (params->xdp_prog)
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bpf_prog_inc(params->xdp_prog);
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rq->xdp_prog = params->xdp_prog;
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rq_xdp_ix = rq->ix;
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if (xsk)
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@ -4406,16 +4403,11 @@ static int mlx5e_xdp_set(struct net_device *netdev, struct bpf_prog *prog)
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/* no need for full reset when exchanging programs */
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reset = (!priv->channels.params.xdp_prog || !prog);
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if (was_opened && !reset) {
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if (was_opened && !reset)
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/* num_channels is invariant here, so we can take the
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* batched reference right upfront.
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*/
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prog = bpf_prog_add(prog, priv->channels.num);
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if (IS_ERR(prog)) {
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err = PTR_ERR(prog);
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goto unlock;
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}
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}
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bpf_prog_add(prog, priv->channels.num);
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if (was_opened && reset) {
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struct mlx5e_channels new_channels = {};
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@ -2107,12 +2107,8 @@ static int qede_start_queues(struct qede_dev *edev, bool clear_stats)
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if (rc)
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goto out;
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fp->rxq->xdp_prog = bpf_prog_add(edev->xdp_prog, 1);
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if (IS_ERR(fp->rxq->xdp_prog)) {
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rc = PTR_ERR(fp->rxq->xdp_prog);
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fp->rxq->xdp_prog = NULL;
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goto out;
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}
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bpf_prog_add(edev->xdp_prog, 1);
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fp->rxq->xdp_prog = edev->xdp_prog;
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}
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if (fp->type & QEDE_FASTPATH_TX) {
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@ -2445,11 +2445,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog,
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if (!prog && !old_prog)
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return 0;
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if (prog) {
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prog = bpf_prog_add(prog, vi->max_queue_pairs - 1);
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if (IS_ERR(prog))
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return PTR_ERR(prog);
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}
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if (prog)
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bpf_prog_add(prog, vi->max_queue_pairs - 1);
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/* Make sure NAPI is not using any XDP TX queues for RX. */
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if (netif_running(dev)) {
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@ -485,7 +485,7 @@ struct bpf_func_info_aux {
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};
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struct bpf_prog_aux {
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atomic_t refcnt;
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atomic64_t refcnt;
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u32 used_map_cnt;
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u32 max_ctx_offset;
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u32 max_pkt_offset;
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@ -770,9 +770,9 @@ extern const struct bpf_verifier_ops xdp_analyzer_ops;
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struct bpf_prog *bpf_prog_get(u32 ufd);
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struct bpf_prog *bpf_prog_get_type_dev(u32 ufd, enum bpf_prog_type type,
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bool attach_drv);
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struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i);
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void bpf_prog_add(struct bpf_prog *prog, int i);
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void bpf_prog_sub(struct bpf_prog *prog, int i);
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struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog);
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void bpf_prog_inc(struct bpf_prog *prog);
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struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog);
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void bpf_prog_put(struct bpf_prog *prog);
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int __bpf_prog_charge(struct user_struct *user, u32 pages);
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@ -912,10 +912,8 @@ static inline struct bpf_prog *bpf_prog_get_type_dev(u32 ufd,
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog,
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int i)
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static inline void bpf_prog_add(struct bpf_prog *prog, int i)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline void bpf_prog_sub(struct bpf_prog *prog, int i)
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@ -926,9 +924,8 @@ static inline void bpf_prog_put(struct bpf_prog *prog)
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{
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}
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static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog)
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static inline void bpf_prog_inc(struct bpf_prog *prog)
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{
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return ERR_PTR(-EOPNOTSUPP);
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}
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static inline struct bpf_prog *__must_check
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@ -31,7 +31,7 @@ static void *bpf_any_get(void *raw, enum bpf_type type)
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{
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switch (type) {
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case BPF_TYPE_PROG:
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raw = bpf_prog_inc(raw);
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bpf_prog_inc(raw);
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break;
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case BPF_TYPE_MAP:
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bpf_map_inc_with_uref(raw);
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if (!bpf_prog_get_ok(prog, &type, false))
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return ERR_PTR(-EINVAL);
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return bpf_prog_inc(prog);
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bpf_prog_inc(prog);
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return prog;
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}
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struct bpf_prog *bpf_prog_get_type_path(const char *name, enum bpf_prog_type type)
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@ -1339,7 +1339,7 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred)
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static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
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{
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if (atomic_dec_and_test(&prog->aux->refcnt)) {
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if (atomic64_dec_and_test(&prog->aux->refcnt)) {
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perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
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/* bpf_prog_free_id() must be called first */
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bpf_prog_free_id(prog, do_idr_lock);
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return f.file->private_data;
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}
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/* prog's refcnt limit */
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#define BPF_MAX_REFCNT 32768
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struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)
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void bpf_prog_add(struct bpf_prog *prog, int i)
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{
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if (atomic_add_return(i, &prog->aux->refcnt) > BPF_MAX_REFCNT) {
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atomic_sub(i, &prog->aux->refcnt);
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return ERR_PTR(-EBUSY);
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}
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return prog;
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atomic64_add(i, &prog->aux->refcnt);
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}
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EXPORT_SYMBOL_GPL(bpf_prog_add);
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@ -1465,13 +1458,13 @@ void bpf_prog_sub(struct bpf_prog *prog, int i)
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* path holds a reference to the program, thus atomic_sub() can
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* be safely used in such cases!
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*/
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WARN_ON(atomic_sub_return(i, &prog->aux->refcnt) == 0);
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WARN_ON(atomic64_sub_return(i, &prog->aux->refcnt) == 0);
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}
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EXPORT_SYMBOL_GPL(bpf_prog_sub);
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struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
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void bpf_prog_inc(struct bpf_prog *prog)
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{
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return bpf_prog_add(prog, 1);
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atomic64_inc(&prog->aux->refcnt);
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}
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EXPORT_SYMBOL_GPL(bpf_prog_inc);
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@ -1480,12 +1473,7 @@ struct bpf_prog *bpf_prog_inc_not_zero(struct bpf_prog *prog)
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{
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int refold;
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refold = atomic_fetch_add_unless(&prog->aux->refcnt, 1, 0);
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if (refold >= BPF_MAX_REFCNT) {
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__bpf_prog_put(prog, false);
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return ERR_PTR(-EBUSY);
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}
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refold = atomic64_fetch_add_unless(&prog->aux->refcnt, 1, 0);
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if (!refold)
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return ERR_PTR(-ENOENT);
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@ -1523,7 +1511,7 @@ static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *attach_type,
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goto out;
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}
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prog = bpf_prog_inc(prog);
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bpf_prog_inc(prog);
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out:
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fdput(f);
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return prog;
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@ -1714,7 +1702,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
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prog->orig_prog = NULL;
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prog->jited = 0;
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atomic_set(&prog->aux->refcnt, 1);
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atomic64_set(&prog->aux->refcnt, 1);
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prog->gpl_compatible = is_gpl ? 1 : 0;
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if (bpf_prog_is_dev_bound(prog->aux)) {
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@ -10477,12 +10477,9 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
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context = parent_event->overflow_handler_context;
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#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_EVENT_TRACING)
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if (overflow_handler == bpf_overflow_handler) {
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struct bpf_prog *prog = bpf_prog_inc(parent_event->prog);
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struct bpf_prog *prog = parent_event->prog;
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if (IS_ERR(prog)) {
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err = PTR_ERR(prog);
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goto err_ns;
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}
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bpf_prog_inc(prog);
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event->prog = prog;
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event->orig_overflow_handler =
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parent_event->orig_overflow_handler;
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