Commit 84c6b868 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

xsk: don't allow umem replace at stack level 



Currently drivers have to check if they already have a umem
installed for a given queue and return an error if so.  Make
better use of XDP_QUERY_XSK_UMEM and move this functionality
to the core.

We need to keep rtnl across the calls now.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: default avatarBjörn Töpel <bjorn.topel@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f734607e

include/linux/netdevice.h

+4 −3
Original line number Diff line number Diff line
@@ -872,10 +872,10 @@ struct netdev_bpf { 
		struct {

			struct bpf_offloaded_map *offmap;

		};

		/* XDP_SETUP_XSK_UMEM */

		/* XDP_QUERY_XSK_UMEM, XDP_SETUP_XSK_UMEM */

		struct {

			struct xdp_umem *umem;

			u16 queue_id;

			struct xdp_umem *umem; /* out for query*/

			u16 queue_id; /* in for query */

		} xsk;

	};

};
@@ -3568,6 +3568,7 @@ int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, 
		      int fd, u32 flags);

u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op,

		    enum bpf_netdev_command cmd);

int xdp_umem_query(struct net_device *dev, u16 queue_id);



int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

int dev_forward_skb(struct net_device *dev, struct sk_buff *skb);

net/xdp/xdp_umem.c

+28 −9
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#include <linux/slab.h>

#include <linux/bpf.h>

#include <linux/mm.h>

#include <linux/netdevice.h>

#include <linux/rtnetlink.h>



#include "xdp_umem.h"

#include "xsk_queue.h"
@@ -40,6 +42,21 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs) 
	}

}



int xdp_umem_query(struct net_device *dev, u16 queue_id)

{

	struct netdev_bpf bpf;



	ASSERT_RTNL();



	memset(&bpf, 0, sizeof(bpf));

	bpf.command = XDP_QUERY_XSK_UMEM;

	bpf.xsk.queue_id = queue_id;



	if (!dev->netdev_ops->ndo_bpf)

		return 0;

	return dev->netdev_ops->ndo_bpf(dev, &bpf) ?: !!bpf.xsk.umem;

}



int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,

			u32 queue_id, u16 flags)

{
@@ -62,28 +79,30 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev, 
	bpf.command = XDP_QUERY_XSK_UMEM;



	rtnl_lock();

	err = dev->netdev_ops->ndo_bpf(dev, &bpf);

	rtnl_unlock();



	if (err)

		return force_zc ? -ENOTSUPP : 0;

	err = xdp_umem_query(dev, queue_id);

	if (err) {

		err = err < 0 ? -ENOTSUPP : -EBUSY;

		goto err_rtnl_unlock;

	}



	bpf.command = XDP_SETUP_XSK_UMEM;

	bpf.xsk.umem = umem;

	bpf.xsk.queue_id = queue_id;



	rtnl_lock();

	err = dev->netdev_ops->ndo_bpf(dev, &bpf);

	rtnl_unlock();



	if (err)

		return force_zc ? err : 0; /* fail or fallback */

		goto err_rtnl_unlock;

	rtnl_unlock();



	dev_hold(dev);

	umem->dev = dev;

	umem->queue_id = queue_id;

	umem->zc = true;

	return 0;



err_rtnl_unlock:

	rtnl_unlock();

	return force_zc ? err : 0; /* fail or fallback */

}



static void xdp_umem_clear_dev(struct xdp_umem *umem)

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