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

Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-12-03

The main changes are:

1) Support BTF in kernel modules, from Andrii.

2) Introduce preferred busy-polling, from Björn.

3) bpf_ima_inode_hash() and bpf_bprm_opts_set() helpers, from KP Singh.

4) Memcg-based memory accounting for bpf objects, from Roman.

5) Allow bpf_{s,g}etsockopt from cgroup bind{4,6} hooks, from Stanislav.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (118 commits)
  selftests/bpf: Fix invalid use of strncat in test_sockmap
  libbpf: Use memcpy instead of strncpy to please GCC
  selftests/bpf: Add fentry/fexit/fmod_ret selftest for kernel module
  selftests/bpf: Add tp_btf CO-RE reloc test for modules
  libbpf: Support attachment of BPF tracing programs to kernel modules
  libbpf: Factor out low-level BPF program loading helper
  bpf: Allow to specify kernel module BTFs when attaching BPF programs
  bpf: Remove hard-coded btf_vmlinux assumption from BPF verifier
  selftests/bpf: Add CO-RE relocs selftest relying on kernel module BTF
  selftests/bpf: Add support for marking sub-tests as skipped
  selftests/bpf: Add bpf_testmod kernel module for testing
  libbpf: Add kernel module BTF support for CO-RE relocations
  libbpf: Refactor CO-RE relocs to not assume a single BTF object
  libbpf: Add internal helper to load BTF data by FD
  bpf: Keep module's btf_data_size intact after load
  bpf: Fix bpf_put_raw_tracepoint()'s use of __module_address()
  selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP
  bpf: Adds support for setting window clamp
  samples/bpf: Fix spelling mistake "recieving" -> "receiving"
  bpf: Fix cold build of test_progs-no_alu32
  ...
====================

Link: https://lore.kernel.org/r/20201204021936.85653-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 201 insertions, 56 deletions

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index b7b039bd9d03..56c46e5f57bc 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -23,6 +23,7 @@
 #include <linux/netdevice.h>
 #include <linux/rculist.h>
 #include <net/xdp_sock_drv.h>
+#include <net/busy_poll.h>
 #include <net/xdp.h>
 
 #include "xsk_queue.h"
@@ -232,6 +233,7 @@ static int xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp,
 	if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index)
 		return -EINVAL;
 
+	sk_mark_napi_id_once_xdp(&xs->sk, xdp);
 	len = xdp->data_end - xdp->data;
 
 	return xdp->rxq->mem.type == MEM_TYPE_XSK_BUFF_POOL ?
@@ -332,6 +334,63 @@ out:
 }
 EXPORT_SYMBOL(xsk_tx_peek_desc);
 
+static u32 xsk_tx_peek_release_fallback(struct xsk_buff_pool *pool, struct xdp_desc *descs,
+					u32 max_entries)
+{
+	u32 nb_pkts = 0;
+
+	while (nb_pkts < max_entries && xsk_tx_peek_desc(pool, &descs[nb_pkts]))
+		nb_pkts++;
+
+	xsk_tx_release(pool);
+	return nb_pkts;
+}
+
+u32 xsk_tx_peek_release_desc_batch(struct xsk_buff_pool *pool, struct xdp_desc *descs,
+				   u32 max_entries)
+{
+	struct xdp_sock *xs;
+	u32 nb_pkts;
+
+	rcu_read_lock();
+	if (!list_is_singular(&pool->xsk_tx_list)) {
+		/* Fallback to the non-batched version */
+		rcu_read_unlock();
+		return xsk_tx_peek_release_fallback(pool, descs, max_entries);
+	}
+
+	xs = list_first_or_null_rcu(&pool->xsk_tx_list, struct xdp_sock, tx_list);
+	if (!xs) {
+		nb_pkts = 0;
+		goto out;
+	}
+
+	nb_pkts = xskq_cons_peek_desc_batch(xs->tx, descs, pool, max_entries);
+	if (!nb_pkts) {
+		xs->tx->queue_empty_descs++;
+		goto out;
+	}
+
+	/* This is the backpressure mechanism for the Tx path. Try to
+	 * reserve space in the completion queue for all packets, but
+	 * if there are fewer slots available, just process that many
+	 * packets. This avoids having to implement any buffering in
+	 * the Tx path.
+	 */
+	nb_pkts = xskq_prod_reserve_addr_batch(pool->cq, descs, nb_pkts);
+	if (!nb_pkts)
+		goto out;
+
+	xskq_cons_release_n(xs->tx, nb_pkts);
+	__xskq_cons_release(xs->tx);
+	xs->sk.sk_write_space(&xs->sk);
+
+out:
+	rcu_read_unlock();
+	return nb_pkts;
+}
+EXPORT_SYMBOL(xsk_tx_peek_release_desc_batch);
+
 static int xsk_wakeup(struct xdp_sock *xs, u8 flags)
 {
 	struct net_device *dev = xs->dev;
@@ -454,18 +513,65 @@ static int __xsk_sendmsg(struct sock *sk)
 	return xs->zc ? xsk_zc_xmit(xs) : xsk_generic_xmit(sk);
 }
 
+static bool xsk_no_wakeup(struct sock *sk)
+{
+#ifdef CONFIG_NET_RX_BUSY_POLL
+	/* Prefer busy-polling, skip the wakeup. */
+	return READ_ONCE(sk->sk_prefer_busy_poll) && READ_ONCE(sk->sk_ll_usec) &&
+		READ_ONCE(sk->sk_napi_id) >= MIN_NAPI_ID;
+#else
+	return false;
+#endif
+}
+
 static int xsk_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len)
 {
 	bool need_wait = !(m->msg_flags & MSG_DONTWAIT);
 	struct sock *sk = sock->sk;
 	struct xdp_sock *xs = xdp_sk(sk);
+	struct xsk_buff_pool *pool;
 
 	if (unlikely(!xsk_is_bound(xs)))
 		return -ENXIO;
 	if (unlikely(need_wait))
 		return -EOPNOTSUPP;
 
-	return __xsk_sendmsg(sk);
+	if (sk_can_busy_loop(sk))
+		sk_busy_loop(sk, 1); /* only support non-blocking sockets */
+
+	if (xsk_no_wakeup(sk))
+		return 0;
+
+	pool = xs->pool;
+	if (pool->cached_need_wakeup & XDP_WAKEUP_TX)
+		return __xsk_sendmsg(sk);
+	return 0;
+}
+
+static int xsk_recvmsg(struct socket *sock, struct msghdr *m, size_t len, int flags)
+{
+	bool need_wait = !(flags & MSG_DONTWAIT);
+	struct sock *sk = sock->sk;
+	struct xdp_sock *xs = xdp_sk(sk);
+
+	if (unlikely(!(xs->dev->flags & IFF_UP)))
+		return -ENETDOWN;
+	if (unlikely(!xs->rx))
+		return -ENOBUFS;
+	if (unlikely(!xsk_is_bound(xs)))
+		return -ENXIO;
+	if (unlikely(need_wait))
+		return -EOPNOTSUPP;
+
+	if (sk_can_busy_loop(sk))
+		sk_busy_loop(sk, 1); /* only support non-blocking sockets */
+
+	if (xsk_no_wakeup(sk))
+		return 0;
+
+	if (xs->pool->cached_need_wakeup & XDP_WAKEUP_RX && xs->zc)
+		return xsk_wakeup(xs, XDP_WAKEUP_RX);
+	return 0;
 }
 
 static __poll_t xsk_poll(struct file *file, struct socket *sock,
@@ -542,7 +648,7 @@ static struct xsk_map *xsk_get_map_list_entry(struct xdp_sock *xs,
 	node = list_first_entry_or_null(&xs->map_list, struct xsk_map_node,
 					node);
 	if (node) {
-		WARN_ON(xsk_map_inc(node->map));
+		bpf_map_inc(&node->map->map);
 		map = node->map;
 		*map_entry = node->map_entry;
 	}
@@ -572,7 +678,7 @@ static void xsk_delete_from_maps(struct xdp_sock *xs)
 
 	while ((map = xsk_get_map_list_entry(xs, &map_entry))) {
 		xsk_map_try_sock_delete(map, xs, map_entry);
-		xsk_map_put(map);
+		bpf_map_put(&map->map);
 	}
 }
 
@@ -1128,7 +1234,7 @@ static const struct proto_ops xsk_proto_ops = {
 	.setsockopt	= xsk_setsockopt,
 	.getsockopt	= xsk_getsockopt,
 	.sendmsg	= xsk_sendmsg,
-	.recvmsg	= sock_no_recvmsg,
+	.recvmsg	= xsk_recvmsg,
 	.mmap		= xsk_mmap,
 	.sendpage	= sock_no_sendpage,
 };
diff --git a/net/xdp/xsk.h b/net/xdp/xsk.h
index b9e896cee5bb..edcf249ad1f1 100644
--- a/net/xdp/xsk.h
+++ b/net/xdp/xsk.h
@@ -41,8 +41,6 @@ static inline struct xdp_sock *xdp_sk(struct sock *sk)
 
 void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
 			     struct xdp_sock **map_entry);
-int xsk_map_inc(struct xsk_map *map);
-void xsk_map_put(struct xsk_map *map);
 void xsk_clear_pool_at_qid(struct net_device *dev, u16 queue_id);
 int xsk_reg_pool_at_qid(struct net_device *dev, struct xsk_buff_pool *pool,
 			u16 queue_id);
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index 9287eddec52c..556d82d03687 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -144,14 +144,13 @@ static int __xp_assign_dev(struct xsk_buff_pool *pool,
 	if (err)
 		return err;
 
-	if (flags & XDP_USE_NEED_WAKEUP) {
+	if (flags & XDP_USE_NEED_WAKEUP)
 		pool->uses_need_wakeup = true;
-		/* Tx needs to be explicitly woken up the first time.
-		 * Also for supporting drivers that do not implement this
-		 * feature. They will always have to call sendto().
-		 */
-		pool->cached_need_wakeup = XDP_WAKEUP_TX;
-	}
+	/* Tx needs to be explicitly woken up the first time.  Also
+	 * for supporting drivers that do not implement this
+	 * feature. They will always have to call sendto() or poll().
+	 */
+	pool->cached_need_wakeup = XDP_WAKEUP_TX;
 
 	dev_hold(netdev);
 
diff --git a/net/xdp/xsk_queue.h b/net/xdp/xsk_queue.h
index cdb9cf3cd136..b936c46b1e16 100644
--- a/net/xdp/xsk_queue.h
+++ b/net/xdp/xsk_queue.h
@@ -18,9 +18,11 @@ struct xdp_ring {
 	/* Hinder the adjacent cache prefetcher to prefetch the consumer
 	 * pointer if the producer pointer is touched and vice versa.
 	 */
-	u32 pad ____cacheline_aligned_in_smp;
+	u32 pad1 ____cacheline_aligned_in_smp;
 	u32 consumer ____cacheline_aligned_in_smp;
+	u32 pad2 ____cacheline_aligned_in_smp;
 	u32 flags;
+	u32 pad3 ____cacheline_aligned_in_smp;
 };
 
 /* Used for the RX and TX queues for packets */
@@ -197,6 +199,30 @@ static inline bool xskq_cons_read_desc(struct xsk_queue *q,
 	return false;
 }
 
+static inline u32 xskq_cons_read_desc_batch(struct xsk_queue *q,
+					    struct xdp_desc *descs,
+					    struct xsk_buff_pool *pool, u32 max)
+{
+	u32 cached_cons = q->cached_cons, nb_entries = 0;
+
+	while (cached_cons != q->cached_prod && nb_entries < max) {
+		struct xdp_rxtx_ring *ring = (struct xdp_rxtx_ring *)q->ring;
+		u32 idx = cached_cons & q->ring_mask;
+
+		descs[nb_entries] = ring->desc[idx];
+		if (unlikely(!xskq_cons_is_valid_desc(q, &descs[nb_entries], pool))) {
+			/* Skip the entry */
+			cached_cons++;
+			continue;
+		}
+
+		nb_entries++;
+		cached_cons++;
+	}
+
+	return nb_entries;
+}
+
 /* Functions for consumers */
 
 static inline void __xskq_cons_release(struct xsk_queue *q)
@@ -218,17 +244,22 @@ static inline void xskq_cons_get_entries(struct xsk_queue *q)
 	__xskq_cons_peek(q);
 }
 
-static inline bool xskq_cons_has_entries(struct xsk_queue *q, u32 cnt)
+static inline u32 xskq_cons_nb_entries(struct xsk_queue *q, u32 max)
 {
 	u32 entries = q->cached_prod - q->cached_cons;
 
-	if (entries >= cnt)
-		return true;
+	if (entries >= max)
+		return max;
 
 	__xskq_cons_peek(q);
 	entries = q->cached_prod - q->cached_cons;
 
-	return entries >= cnt;
+	return entries >= max ? max : entries;
+}
+
+static inline bool xskq_cons_has_entries(struct xsk_queue *q, u32 cnt)
+{
+	return xskq_cons_nb_entries(q, cnt) >= cnt ? true : false;
 }
 
 static inline bool xskq_cons_peek_addr_unchecked(struct xsk_queue *q, u64 *addr)
@@ -247,16 +278,28 @@ static inline bool xskq_cons_peek_desc(struct xsk_queue *q,
 	return xskq_cons_read_desc(q, desc, pool);
 }
 
+static inline u32 xskq_cons_peek_desc_batch(struct xsk_queue *q, struct xdp_desc *descs,
+					    struct xsk_buff_pool *pool, u32 max)
+{
+	u32 entries = xskq_cons_nb_entries(q, max);
+
+	return xskq_cons_read_desc_batch(q, descs, pool, entries);
+}
+
+/* To improve performance in the xskq_cons_release functions, only update local state here.
+ * Reflect this to global state when we get new entries from the ring in
+ * xskq_cons_get_entries() and whenever Rx or Tx processing are completed in the NAPI loop.
+ */
 static inline void xskq_cons_release(struct xsk_queue *q)
 {
-	/* To improve performance, only update local state here.
-	 * Reflect this to global state when we get new entries
-	 * from the ring in xskq_cons_get_entries() and whenever
-	 * Rx or Tx processing are completed in the NAPI loop.
-	 */
 	q->cached_cons++;
 }
 
+static inline void xskq_cons_release_n(struct xsk_queue *q, u32 cnt)
+{
+	q->cached_cons += cnt;
+}
+
 static inline bool xskq_cons_is_full(struct xsk_queue *q)
 {
 	/* No barriers needed since data is not accessed */
@@ -266,18 +309,23 @@ static inline bool xskq_cons_is_full(struct xsk_queue *q)
 
 /* Functions for producers */
 
-static inline bool xskq_prod_is_full(struct xsk_queue *q)
+static inline u32 xskq_prod_nb_free(struct xsk_queue *q, u32 max)
 {
 	u32 free_entries = q->nentries - (q->cached_prod - q->cached_cons);
 
-	if (free_entries)
-		return false;
+	if (free_entries >= max)
+		return max;
 
 	/* Refresh the local tail pointer */
 	q->cached_cons = READ_ONCE(q->ring->consumer);
 	free_entries = q->nentries - (q->cached_prod - q->cached_cons);
 
-	return !free_entries;
+	return free_entries >= max ? max : free_entries;
+}
+
+static inline bool xskq_prod_is_full(struct xsk_queue *q)
+{
+	return xskq_prod_nb_free(q, 1) ? false : true;
 }
 
 static inline int xskq_prod_reserve(struct xsk_queue *q)
@@ -302,6 +350,23 @@ static inline int xskq_prod_reserve_addr(struct xsk_queue *q, u64 addr)
 	return 0;
 }
 
+static inline u32 xskq_prod_reserve_addr_batch(struct xsk_queue *q, struct xdp_desc *descs,
+					       u32 max)
+{
+	struct xdp_umem_ring *ring = (struct xdp_umem_ring *)q->ring;
+	u32 nb_entries, i, cached_prod;
+
+	nb_entries = xskq_prod_nb_free(q, max);
+
+	/* A, matches D */
+	cached_prod = q->cached_prod;
+	for (i = 0; i < nb_entries; i++)
+		ring->desc[cached_prod++ & q->ring_mask] = descs[i].addr;
+	q->cached_prod = cached_prod;
+
+	return nb_entries;
+}
+
 static inline int xskq_prod_reserve_desc(struct xsk_queue *q,
 					 u64 addr, u32 len)
 {
diff --git a/net/xdp/xskmap.c b/net/xdp/xskmap.c
index 49da2b8ace8b..113fd9017203 100644
--- a/net/xdp/xskmap.c
+++ b/net/xdp/xskmap.c
@@ -11,32 +11,17 @@
 
 #include "xsk.h"
 
-int xsk_map_inc(struct xsk_map *map)
-{
-	bpf_map_inc(&map->map);
-	return 0;
-}
-
-void xsk_map_put(struct xsk_map *map)
-{
-	bpf_map_put(&map->map);
-}
-
 static struct xsk_map_node *xsk_map_node_alloc(struct xsk_map *map,
 					       struct xdp_sock **map_entry)
 {
 	struct xsk_map_node *node;
-	int err;
 
-	node = kzalloc(sizeof(*node), GFP_ATOMIC | __GFP_NOWARN);
+	node = bpf_map_kzalloc(&map->map, sizeof(*node),
+			       GFP_ATOMIC | __GFP_NOWARN);
 	if (!node)
 		return ERR_PTR(-ENOMEM);
 
-	err = xsk_map_inc(map);
-	if (err) {
-		kfree(node);
-		return ERR_PTR(err);
-	}
+	bpf_map_inc(&map->map);
 
 	node->map = map;
 	node->map_entry = map_entry;
@@ -45,7 +30,7 @@ static struct xsk_map_node *xsk_map_node_alloc(struct xsk_map *map,
 
 static void xsk_map_node_free(struct xsk_map_node *node)
 {
-	xsk_map_put(node->map);
+	bpf_map_put(&node->map->map);
 	kfree(node);
 }
 
@@ -73,9 +58,8 @@ static void xsk_map_sock_delete(struct xdp_sock *xs,
 
 static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
 {
-	struct bpf_map_memory mem;
-	int err, numa_node;
 	struct xsk_map *m;
+	int numa_node;
 	u64 size;
 
 	if (!capable(CAP_NET_ADMIN))
@@ -89,18 +73,11 @@ static struct bpf_map *xsk_map_alloc(union bpf_attr *attr)
 	numa_node = bpf_map_attr_numa_node(attr);
 	size = struct_size(m, xsk_map, attr->max_entries);
 
-	err = bpf_map_charge_init(&mem, size);
-	if (err < 0)
-		return ERR_PTR(err);
-
 	m = bpf_map_area_alloc(size, numa_node);
-	if (!m) {
-		bpf_map_charge_finish(&mem);
+	if (!m)
 		return ERR_PTR(-ENOMEM);
-	}
 
 	bpf_map_init_from_attr(&m->map, attr);
-	bpf_map_charge_move(&m->map.memory, &mem);
 	spin_lock_init(&m->lock);
 
 	return &m->map;