Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2020-11-28

1) Do not reference the skb for xsk's generic TX side since when looped
back into RX it might crash in generic XDP, from Björn Töpel.

2) Fix umem cleanup on a partially set up xsk socket when being destroyed,
from Magnus Karlsson.

3) Fix an incorrect netdev reference count when failing xsk_bind() operation,
from Marek Majtyka.

4) Fix bpftool to set an error code on failed calloc() in build_btf_type_table(),
from Zhen Lei.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Add MAINTAINERS entry for BPF LSM
bpftool: Fix error return value in build_btf_type_table
net, xsk: Avoid taking multiple skbuff references
xsk: Fix incorrect netdev reference count
xsk: Fix umem cleanup bug at socket destruct
MAINTAINERS: Update XDP and AF_XDP entries
====================

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

MAINTAINERS

···
 F:	arch/x86/net/
 X:	arch/x86/net/bpf_jit_comp32.c
 
+BPF LSM (Security Audit and Enforcement using BPF)
+M:	KP Singh <[e-mail]>
+R:	Florent Revest <[e-mail]>
+R:	Brendan Jackman <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	Documentation/bpf/bpf_lsm.rst
+F:	include/linux/bpf_lsm.h
+F:	kernel/bpf/bpf_lsm.c
+F:	security/bpf/
+
 BROADCOM B44 10/100 ETHERNET DRIVER
 M:	Michael Chan <[e-mail]>
 L:	[e-mail]
···
 L:	[e-mail]
 S:	Supported
 F:	include/net/xdp.h
+F:	include/net/xdp_priv.h
 F:	include/trace/events/xdp.h
 F:	kernel/bpf/cpumap.c
 F:	kernel/bpf/devmap.c
 F:	net/core/xdp.c
-N:	xdp
-K:	xdp
+F:	samples/bpf/xdp*
+F:	tools/testing/selftests/bpf/*xdp*
+F:	tools/testing/selftests/bpf/*/*xdp*
+F:	drivers/net/ethernet/*/*/*/*/*xdp*
+F:	drivers/net/ethernet/*/*/*xdp*
+K:	(?:\b|_)xdp(?:\b|_)
 
 XDP SOCKETS (AF_XDP)
 M:	Björn Töpel <[e-mail]>
···
 L:	[e-mail]
 L:	[e-mail]
 S:	Maintained
+F:	Documentation/networking/af_xdp.rst
 F:	include/net/xdp_sock*
 F:	include/net/xsk_buff_pool.h
 F:	include/uapi/linux/if_xdp.h
+F:	include/uapi/linux/xdp_diag.h
+F:	include/net/netns/xdp.h
 F:	net/xdp/
 F:	samples/bpf/xdpsock*
 F:	tools/lib/bpf/xsk*

include/linux/netdevice.h

···
 		     struct net_device *sb_dev);
 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
 		       struct net_device *sb_dev);
+
 int dev_queue_xmit(struct sk_buff *skb);
 int dev_queue_xmit_accel(struct sk_buff *skb, struct net_device *sb_dev);
-int dev_direct_xmit(struct sk_buff *skb, u16 queue_id);
+int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id);
+
+static inline int dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
+{
+	int ret;
+
+	ret = __dev_direct_xmit(skb, queue_id);
+	if (!dev_xmit_complete(ret))
+		kfree_skb(skb);
+	return ret;
+}
+
 int register_netdevice(struct net_device *dev);
 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head);
 void unregister_netdevice_many(struct list_head *head);

include/net/xdp_sock.h

···
 	struct page **pgs;
 	int id;
 	struct list_head xsk_dma_list;
+	struct work_struct work;
 };
 
 struct xsk_map {

net/core/dev.c

···
 }
 EXPORT_SYMBOL(dev_queue_xmit_accel);
 
-int dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
+int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
 {
 	struct net_device *dev = skb->dev;
 	struct sk_buff *orig_skb = skb;
···
 	dev_xmit_recursion_dec();
 
 	local_bh_enable();
-
-	if (!dev_xmit_complete(ret))
-		kfree_skb(skb);
-
 	return ret;
 drop:
 	atomic_long_inc(&dev->tx_dropped);
 	kfree_skb_list(skb);
 	return NET_XMIT_DROP;
 }
-EXPORT_SYMBOL(dev_direct_xmit);
+EXPORT_SYMBOL(__dev_direct_xmit);
 
 /*************************************************************************
  *			Receiver routines

net/xdp/xdp_umem.c

···
 	kfree(umem);
 }
 
+static void xdp_umem_release_deferred(struct work_struct *work)
+{
+	struct xdp_umem *umem = container_of(work, struct xdp_umem, work);
+
+	xdp_umem_release(umem);
+}
+
 void xdp_get_umem(struct xdp_umem *umem)
 {
 	refcount_inc(&umem->users);
 }
 
-void xdp_put_umem(struct xdp_umem *umem)
+void xdp_put_umem(struct xdp_umem *umem, bool defer_cleanup)
 {
 	if (!umem)
 		return;
 
-	if (refcount_dec_and_test(&umem->users))
-		xdp_umem_release(umem);
+	if (refcount_dec_and_test(&umem->users)) {
+		if (defer_cleanup) {
+			INIT_WORK(&umem->work, xdp_umem_release_deferred);
+			schedule_work(&umem->work);
+		} else {
+			xdp_umem_release(umem);
+		}
+	}
 }
 
 static int xdp_umem_pin_pages(struct xdp_umem *umem, unsigned long address)

net/xdp/xdp_umem.h

···
 #include <net/xdp_sock_drv.h>
 
 void xdp_get_umem(struct xdp_umem *umem);
-void xdp_put_umem(struct xdp_umem *umem);
+void xdp_put_umem(struct xdp_umem *umem, bool defer_cleanup);
 struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr);
 
 #endif /* XDP_UMEM_H_ */

net/xdp/xsk.c

···
 		skb_shinfo(skb)->destructor_arg = (void *)(long)desc.addr;
 		skb->destructor = xsk_destruct_skb;
 
-		/* Hinder dev_direct_xmit from freeing the packet and
-		 * therefore completing it in the destructor
-		 */
-		refcount_inc(&skb->users);
-		err = dev_direct_xmit(skb, xs->queue_id);
+		err = __dev_direct_xmit(skb, xs->queue_id);
 		if  (err == NETDEV_TX_BUSY) {
 			/* Tell user-space to retry the send */
 			skb->destructor = sock_wfree;
···
 		/* Ignore NET_XMIT_CN as packet might have been sent */
 		if (err == NET_XMIT_DROP) {
 			/* SKB completed but not sent */
-			kfree_skb(skb);
 			err = -EBUSY;
 			goto out;
 		}
 
-		consume_skb(skb);
 		sent_frame = true;
 	}
 
···
 		return;
 
 	if (!xp_put_pool(xs->pool))
-		xdp_put_umem(xs->umem);
+		xdp_put_umem(xs->umem, !xs->pool);
 
 	sk_refcnt_debug_dec(sk);
 }

net/xdp/xsk_buff_pool.c

···
 err_unreg_pool:
 	if (!force_zc)
 		err = 0; /* fallback to copy mode */
-	if (err)
+	if (err) {
 		xsk_clear_pool_at_qid(netdev, queue_id);
+		dev_put(netdev);
+	}
 	return err;
 }
 
···
 		pool->cq = NULL;
 	}
 
-	xdp_put_umem(pool->umem);
+	xdp_put_umem(pool->umem, false);
 	xp_destroy(pool);
 }
 

tools/bpf/bpftool/btf.c

···
 		obj_node = calloc(1, sizeof(*obj_node));
 		if (!obj_node) {
 			p_err("failed to allocate memory: %s", strerror(errno));
+			err = -ENOMEM;
 			goto err_free;
 		}