Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Millar:
 "Here are some highlights from the 2065 networking commits that
  happened this development cycle:

   1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri)

   2) Add a generic XDP driver, so that anyone can test XDP even if they
      lack a networking device whose driver has explicit XDP support
      (me).

   3) Sparc64 now has an eBPF JIT too (me)

   4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei
      Starovoitov)

   5) Make netfitler network namespace teardown less expensive (Florian
      Westphal)

   6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana)

   7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger)

   8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky)

   9) Multiqueue support in stmmac driver (Joao Pinto)

  10) Remove TCP timewait recycling, it never really could possibly work
      well in the real world and timestamp randomization really zaps any
      hint of usability this feature had (Soheil Hassas Yeganeh)

  11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay
      Aleksandrov)

  12) Add socket busy poll support to epoll (Sridhar Samudrala)

  13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso,
      and several others)

  14) IPSEC hw offload infrastructure (Steffen Klassert)"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2065 commits)
  tipc: refactor function tipc_sk_recv_stream()
  tipc: refactor function tipc_sk_recvmsg()
  net: thunderx: Optimize page recycling for XDP
  net: thunderx: Support for XDP header adjustment
  net: thunderx: Add support for XDP_TX
  net: thunderx: Add support for XDP_DROP
  net: thunderx: Add basic XDP support
  net: thunderx: Cleanup receive buffer allocation
  net: thunderx: Optimize CQE_TX handling
  net: thunderx: Optimize RBDR descriptor handling
  net: thunderx: Support for page recycling
  ipx: call ipxitf_put() in ioctl error path
  net: sched: add helpers to handle extended actions
  qed*: Fix issues in the ptp filter config implementation.
  qede: Fix concurrency issue in PTP Tx path processing.
  stmmac: Add support for SIMATIC IOT2000 platform
  net: hns: fix ethtool_get_strings overflow in hns driver
  tcp: fix wraparound issue in tcp_lp
  bpf, arm64: fix jit branch offset related to ldimm64
  bpf, arm64: implement jiting of BPF_XADD
  ...

1 files changed, 50 insertions, 18 deletions

diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h
index 092292b6675e..7d56a7ea2b2e 100644
--- a/include/linux/rhashtable.h
+++ b/include/linux/rhashtable.h
@@ -49,6 +49,21 @@
 /* Base bits plus 1 bit for nulls marker */
 #define RHT_HASH_RESERVED_SPACE	(RHT_BASE_BITS + 1)
 
+/* Maximum chain length before rehash
+ *
+ * The maximum (not average) chain length grows with the size of the hash
+ * table, at a rate of (log N)/(log log N).
+ *
+ * The value of 16 is selected so that even if the hash table grew to
+ * 2^32 you would not expect the maximum chain length to exceed it
+ * unless we are under attack (or extremely unlucky).
+ *
+ * As this limit is only to detect attacks, we don't need to set it to a
+ * lower value as you'd need the chain length to vastly exceed 16 to have
+ * any real effect on the system.
+ */
+#define RHT_ELASTICITY	16u
+
 struct rhash_head {
 	struct rhash_head __rcu		*next;
 };
@@ -110,29 +125,25 @@ struct rhashtable;
  * @key_len: Length of key
  * @key_offset: Offset of key in struct to be hashed
  * @head_offset: Offset of rhash_head in struct to be hashed
- * @insecure_max_entries: Maximum number of entries (may be exceeded)
  * @max_size: Maximum size while expanding
  * @min_size: Minimum size while shrinking
- * @nulls_base: Base value to generate nulls marker
- * @insecure_elasticity: Set to true to disable chain length checks
- * @automatic_shrinking: Enable automatic shrinking of tables
  * @locks_mul: Number of bucket locks to allocate per cpu (default: 128)
+ * @automatic_shrinking: Enable automatic shrinking of tables
+ * @nulls_base: Base value to generate nulls marker
  * @hashfn: Hash function (default: jhash2 if !(key_len % 4), or jhash)
  * @obj_hashfn: Function to hash object
  * @obj_cmpfn: Function to compare key with object
  */
 struct rhashtable_params {
-	size_t			nelem_hint;
-	size_t			key_len;
-	size_t			key_offset;
-	size_t			head_offset;
-	unsigned int		insecure_max_entries;
+	u16			nelem_hint;
+	u16			key_len;
+	u16			key_offset;
+	u16			head_offset;
 	unsigned int		max_size;
-	unsigned int		min_size;
-	u32			nulls_base;
-	bool			insecure_elasticity;
+	u16			min_size;
 	bool			automatic_shrinking;
-	size_t			locks_mul;
+	u8			locks_mul;
+	u32			nulls_base;
 	rht_hashfn_t		hashfn;
 	rht_obj_hashfn_t	obj_hashfn;
 	rht_obj_cmpfn_t		obj_cmpfn;
@@ -143,8 +154,8 @@ struct rhashtable_params {
  * @tbl: Bucket table
  * @nelems: Number of elements in table
  * @key_len: Key length for hashfn
- * @elasticity: Maximum chain length before rehash
  * @p: Configuration parameters
+ * @max_elems: Maximum number of elements in table
  * @rhlist: True if this is an rhltable
  * @run_work: Deferred worker to expand/shrink asynchronously
  * @mutex: Mutex to protect current/future table swapping
@@ -154,8 +165,8 @@ struct rhashtable {
 	struct bucket_table __rcu	*tbl;
 	atomic_t			nelems;
 	unsigned int			key_len;
-	unsigned int			elasticity;
 	struct rhashtable_params	p;
+	unsigned int			max_elems;
 	bool				rhlist;
 	struct work_struct		run_work;
 	struct mutex                    mutex;
@@ -318,8 +329,7 @@ static inline bool rht_grow_above_100(const struct rhashtable *ht,
 static inline bool rht_grow_above_max(const struct rhashtable *ht,
 				      const struct bucket_table *tbl)
 {
-	return ht->p.insecure_max_entries &&
-	       atomic_read(&ht->nelems) >= ht->p.insecure_max_entries;
+	return atomic_read(&ht->nelems) >= ht->max_elems;
 }
 
 /* The bucket lock is selected based on the hash and protects mutations
@@ -726,7 +736,7 @@ slow_path:
 		return rhashtable_insert_slow(ht, key, obj);
 	}
 
-	elasticity = ht->elasticity;
+	elasticity = RHT_ELASTICITY;
 	pprev = rht_bucket_insert(ht, tbl, hash);
 	data = ERR_PTR(-ENOMEM);
 	if (!pprev)
@@ -916,6 +926,28 @@ static inline int rhashtable_lookup_insert_fast(
 }
 
 /**
+ * rhashtable_lookup_get_insert_fast - lookup and insert object into hash table
+ * @ht:		hash table
+ * @obj:	pointer to hash head inside object
+ * @params:	hash table parameters
+ *
+ * Just like rhashtable_lookup_insert_fast(), but this function returns the
+ * object if it exists, NULL if it did not and the insertion was successful,
+ * and an ERR_PTR otherwise.
+ */
+static inline void *rhashtable_lookup_get_insert_fast(
+	struct rhashtable *ht, struct rhash_head *obj,
+	const struct rhashtable_params params)
+{
+	const char *key = rht_obj(ht, obj);
+
+	BUG_ON(ht->p.obj_hashfn);
+
+	return __rhashtable_insert_fast(ht, key + ht->p.key_offset, obj, params,
+					false);
+}
+
+/**
  * rhashtable_lookup_insert_key - search and insert object to hash table
  *				  with explicit key
  * @ht:		hash table