Revert "net: Add a second bind table hashed by port and address"

This reverts:

commit d5a42de8bdbe ("net: Add a second bind table hashed by port and address")
commit 538aaf9b2383 ("selftests: Add test for timing a bind request to a port with a populated bhash entry")
Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/

There are a few things that need to be fixed here:
* Updating bhash2 in cases where the socket's rcv saddr changes
* Adding bhash2 hashbucket locks

Links to syzbot reports:
https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/
https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/

Fixes: d5a42de8bdbe ("net: Add a second bind table hashed by port and address")
Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com
Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com
Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 9984d23..028513d 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4604,12 +4604,6 @@ void __init tcp_init(void)
 				  SLAB_HWCACHE_ALIGN | SLAB_PANIC |
 				  SLAB_ACCOUNT,
 				  NULL);
-	tcp_hashinfo.bind2_bucket_cachep =
-		kmem_cache_create("tcp_bind2_bucket",
-				  sizeof(struct inet_bind2_bucket), 0,
-				  SLAB_HWCACHE_ALIGN | SLAB_PANIC |
-				  SLAB_ACCOUNT,
-				  NULL);
 
 	/* Size and allocate the main established and bind bucket
 	 * hash tables.
@@ -4632,9 +4626,8 @@ void __init tcp_init(void)
 	if (inet_ehash_locks_alloc(&tcp_hashinfo))
 		panic("TCP: failed to alloc ehash_locks");
 	tcp_hashinfo.bhash =
-		alloc_large_system_hash("TCP bind bhash tables",
-					sizeof(struct inet_bind_hashbucket) +
-					sizeof(struct inet_bind2_hashbucket),
+		alloc_large_system_hash("TCP bind",
+					sizeof(struct inet_bind_hashbucket),
 					tcp_hashinfo.ehash_mask + 1,
 					17, /* one slot per 128 KB of memory */
 					0,
@@ -4643,12 +4636,9 @@ void __init tcp_init(void)
 					0,
 					64 * 1024);
 	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
-	tcp_hashinfo.bhash2 =
-		(struct inet_bind2_hashbucket *)(tcp_hashinfo.bhash + tcp_hashinfo.bhash_size);
 	for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
 		spin_lock_init(&tcp_hashinfo.bhash[i].lock);
 		INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
-		INIT_HLIST_HEAD(&tcp_hashinfo.bhash2[i].chain);
 	}