Commit ee9d5461 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'mlx5-bpf-refcnt-fixes' 



Daniel Borkmann says:

====================
Couple of BPF refcount fixes for mlx5

Various mlx5 bugs on eBPF refcount handling found during review.
Last patch in series adds a __must_check to BPF helpers to make
sure we won't run into it again w/o compiler complaining first.

v2 -> v3:

 - Just reworked patch 2/4 so we don't need bpf_prog_sub().
 - Rebased, rest as is.

v1 -> v2:

 - After discussion with Alexei, we agreed upon rebasing the
   patches against net-next.
 - Since net-next, I've also added the __must_check to enforce
   future users to check for errors.
 - Fixed up commit message #2.
 - Simplify assignment from patch #1 based on Saeed's feedback
   on previous set.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents f81a8a02 6d67942d

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

+25 −8
Original line number Diff line number Diff line
@@ -513,7 +513,13 @@ static int mlx5e_create_rq(struct mlx5e_channel *c, 
	rq->channel = c;

	rq->ix      = c->ix;

	rq->priv    = c->priv;

	rq->xdp_prog = priv->xdp_prog;



	rq->xdp_prog = priv->xdp_prog ? bpf_prog_inc(priv->xdp_prog) : NULL;

	if (IS_ERR(rq->xdp_prog)) {

		err = PTR_ERR(rq->xdp_prog);

		rq->xdp_prog = NULL;

		goto err_rq_wq_destroy;

	}



	rq->buff.map_dir = DMA_FROM_DEVICE;

	if (rq->xdp_prog)
@@ -590,12 +596,11 @@ static int mlx5e_create_rq(struct mlx5e_channel *c, 
	rq->page_cache.head = 0;

	rq->page_cache.tail = 0;



	if (rq->xdp_prog)

		bpf_prog_add(rq->xdp_prog, 1);



	return 0;



err_rq_wq_destroy:

	if (rq->xdp_prog)

		bpf_prog_put(rq->xdp_prog);

	mlx5_wq_destroy(&rq->wq_ctrl);



	return err;
@@ -3139,11 +3144,21 @@ static int mlx5e_xdp_set(struct net_device *netdev, struct bpf_prog *prog) 


	if (was_opened && reset)

		mlx5e_close_locked(netdev);

	if (was_opened && !reset) {

		/* num_channels is invariant here, so we can take the

		 * batched reference right upfront.

		 */

		prog = bpf_prog_add(prog, priv->params.num_channels);

		if (IS_ERR(prog)) {

			err = PTR_ERR(prog);

			goto unlock;

		}

	}



	/* exchange programs */

	/* exchange programs, extra prog reference we got from caller

	 * as long as we don't fail from this point onwards.

	 */

	old_prog = xchg(&priv->xdp_prog, prog);

	if (prog)

		bpf_prog_add(prog, 1);

	if (old_prog)

		bpf_prog_put(old_prog);
@@ -3159,7 +3174,6 @@ static int mlx5e_xdp_set(struct net_device *netdev, struct bpf_prog *prog) 
	/* exchanging programs w/o reset, we update ref counts on behalf

	 * of the channels RQs here.

	 */

	bpf_prog_add(prog, priv->params.num_channels);

	for (i = 0; i < priv->params.num_channels; i++) {

		struct mlx5e_channel *c = priv->channel[i];
@@ -3691,6 +3705,9 @@ static void mlx5e_nic_cleanup(struct mlx5e_priv *priv) 


	if (MLX5_CAP_GEN(mdev, vport_group_manager))

		mlx5_eswitch_unregister_vport_rep(esw, 0);



	if (priv->xdp_prog)

		bpf_prog_put(priv->xdp_prog);

}



static int mlx5e_init_nic_rx(struct mlx5e_priv *priv)

include/linux/bpf.h

+7 −5
Original line number Diff line number Diff line
@@ -233,14 +233,14 @@ void bpf_register_map_type(struct bpf_map_type_list *tl); 


struct bpf_prog *bpf_prog_get(u32 ufd);

struct bpf_prog *bpf_prog_get_type(u32 ufd, enum bpf_prog_type type);

struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i);

struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog, int i);

void bpf_prog_sub(struct bpf_prog *prog, int i);

struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog);

struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog);

void bpf_prog_put(struct bpf_prog *prog);



struct bpf_map *bpf_map_get_with_uref(u32 ufd);

struct bpf_map *__bpf_map_get(struct fd f);

struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref);

struct bpf_map * __must_check bpf_map_inc(struct bpf_map *map, bool uref);

void bpf_map_put_with_uref(struct bpf_map *map);

void bpf_map_put(struct bpf_map *map);

int bpf_map_precharge_memlock(u32 pages);
@@ -299,7 +299,8 @@ static inline struct bpf_prog *bpf_prog_get_type(u32 ufd, 
{

	return ERR_PTR(-EOPNOTSUPP);

}

static inline struct bpf_prog *bpf_prog_add(struct bpf_prog *prog, int i)

static inline struct bpf_prog * __must_check bpf_prog_add(struct bpf_prog *prog,

							  int i)

{

	return ERR_PTR(-EOPNOTSUPP);

}
@@ -311,7 +312,8 @@ static inline void bpf_prog_sub(struct bpf_prog *prog, int i) 
static inline void bpf_prog_put(struct bpf_prog *prog)

{

}

static inline struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)



static inline struct bpf_prog * __must_check bpf_prog_inc(struct bpf_prog *prog)

{

	return ERR_PTR(-EOPNOTSUPP);

}

kernel/bpf/syscall.c

+1 −0
Original line number Diff line number Diff line
@@ -696,6 +696,7 @@ struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog) 
{

	return bpf_prog_add(prog, 1);

}

EXPORT_SYMBOL_GPL(bpf_prog_inc);



static struct bpf_prog *__bpf_prog_get(u32 ufd, enum bpf_prog_type *type)

{

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