path: root/af_unix-Replace-unix_table_lock-with-per-hash-locks.patch

From 7b57f1e4d1906c33ae3a2359e8fa12c7975b8435 Mon Sep 17 00:00:00 2001
From: Scott B <arglebargle@arglebargle.dev>
Date: Tue, 8 Feb 2022 01:26:27 -0800
Subject: [PATCH] af_unix: Replace unix_table_lock with per-hash locks v3

see: https://lore.kernel.org/all/20211124021431.48956-1-kuniyu@amazon.co.jp/

Squashed commit of the following:

commit 1ee0a29e7d84c2a3c0392c5a3829632ca1be9090
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:31 2021 +0900

    af_unix: Relax race in unix_autobind().

    When we bind an AF_UNIX socket without a name specified, the kernel selects
    an available one from 0x00000 to 0xFFFFF.  unix_autobind() starts searching
    from a number in the 'static' variable and increments it after acquiring
    two locks.

    If multiple processes try autobind, they obtain the same lock and check if
    a socket in the hash list has the same name.  If not, one process uses it,
    and all except one end up retrying the _next_ number (actually not, it may
    be incremented by the other processes).  The more we autobind sockets in
    parallel, the longer the latency gets.  We can avoid such a race by
    searching for a name from a random number.

    These show latency in unix_autobind() while 64 CPUs are simultaneously
    autobind-ing 1024 sockets for each.

      Without this patch:

         usec          : count     distribution
            0          : 1176     |***                                     |
            2          : 3655     |***********                             |
            4          : 4094     |*************                           |
            6          : 3831     |************                            |
            8          : 3829     |************                            |
            10         : 3844     |************                            |
            12         : 3638     |***********                             |
            14         : 2992     |*********                               |
            16         : 2485     |*******                                 |
            18         : 2230     |*******                                 |
            20         : 2095     |******                                  |
            22         : 1853     |*****                                   |
            24         : 1827     |*****                                   |
            26         : 1677     |*****                                   |
            28         : 1473     |****                                    |
            30         : 1573     |*****                                   |
            32         : 1417     |****                                    |
            34         : 1385     |****                                    |
            36         : 1345     |****                                    |
            38         : 1344     |****                                    |
            40         : 1200     |***                                     |

      With this patch:

         usec          : count     distribution
            0          : 1855     |******                                  |
            2          : 6464     |*********************                   |
            4          : 9936     |********************************        |
            6          : 12107    |****************************************|
            8          : 10441    |**********************************      |
            10         : 7264     |***********************                 |
            12         : 4254     |**************                          |
            14         : 2538     |********                                |
            16         : 1596     |*****                                   |
            18         : 1088     |***                                     |
            20         : 800      |**                                      |
            22         : 670      |**                                      |
            24         : 601      |*                                       |
            26         : 562      |*                                       |
            28         : 525      |*                                       |
            30         : 446      |*                                       |
            32         : 378      |*                                       |
            34         : 337      |*                                       |
            36         : 317      |*                                       |
            38         : 314      |*                                       |
            40         : 298      |                                        |

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 6e8cb0f31a1857cbb990f5baecfc4ad37f0dbe1c
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:30 2021 +0900

    af_unix: Replace the big lock with small locks.

    The hash table of AF_UNIX sockets is protected by the single lock.  This
    patch replaces it with per-hash locks.

    The effect is noticeable when we handle multiple sockets simultaneously.
    Here is a test result on an EC2 c5.24xlarge instance.  It shows latency
    (under 10us only) in unix_insert_unbound_socket() while 64 CPUs creating
    1024 sockets for each in parallel.

      Without this patch:

         nsec          : count     distribution
            0          : 179      |                                        |
            500        : 3021     |*********                               |
            1000       : 6271     |*******************                     |
            1500       : 6318     |*******************                     |
            2000       : 5828     |*****************                       |
            2500       : 5124     |***************                         |
            3000       : 4426     |*************                           |
            3500       : 3672     |***********                             |
            4000       : 3138     |*********                               |
            4500       : 2811     |********                                |
            5000       : 2384     |*******                                 |
            5500       : 2023     |******                                  |
            6000       : 1954     |*****                                   |
            6500       : 1737     |*****                                   |
            7000       : 1749     |*****                                   |
            7500       : 1520     |****                                    |
            8000       : 1469     |****                                    |
            8500       : 1394     |****                                    |
            9000       : 1232     |***                                     |
            9500       : 1138     |***                                     |
            10000      : 994      |***                                     |

      With this patch:

         nsec          : count     distribution
            0          : 1634     |****                                    |
            500        : 13170    |****************************************|
            1000       : 13156    |*************************************** |
            1500       : 9010     |***************************             |
            2000       : 6363     |*******************                     |
            2500       : 4443     |*************                           |
            3000       : 3240     |*********                               |
            3500       : 2549     |*******                                 |
            4000       : 1872     |*****                                   |
            4500       : 1504     |****                                    |
            5000       : 1247     |***                                     |
            5500       : 1035     |***                                     |
            6000       : 889      |**                                      |
            6500       : 744      |**                                      |
            7000       : 634      |*                                       |
            7500       : 498      |*                                       |
            8000       : 433      |*                                       |
            8500       : 355      |*                                       |
            9000       : 336      |*                                       |
            9500       : 284      |                                        |
            10000      : 243      |                                        |

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 59e4b2ef18bc14c5f5b4f49b7dad5deec5aace58
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:29 2021 +0900

    af_unix: Save hash in sk_hash.

    To replace unix_table_lock with per-hash locks in the next patch, we need
    to save a hash in each socket because /proc/net/unix or BPF prog iterate
    sockets while holding a hash table lock and release it later in a different
    function.

    Currently, we store a real/pseudo hash in struct unix_address.  However, we
    do not allocate it to unbound sockets, nor should we do just for that.  For
    this purpose, we can use sk_hash.  Then, we no longer use the hash field in
    struct unix_address and can remove it.

    Also, this patch does
      - rename unix_insert_socket() to unix_insert_unbound_socket()
      - remove the redundant list argument from __unix_insert_socket() and
         unix_insert_unbound_socket()
      - use 'unsigned int' instead of 'unsigned' in __unix_set_addr_hash()
      - remove 'inline' from unix_remove_socket() and
         unix_insert_unbound_socket().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 7b723a743faa8a5534b05566786301ebebb043ba
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:28 2021 +0900

    af_unix: Add helpers to calculate hashes.

    This patch adds three helper functions that calculate hashes for unbound
    sockets and bound sockets with BSD/abstract addresses.

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 161596cdc0b6965890aa397c5bd4cd7a86a0d400
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:27 2021 +0900

    af_unix: Remove UNIX_ABSTRACT() macro and test sun_path[0] instead.

    In BSD and abstract address cases, we store sockets in the hash table with
    keys between 0 and UNIX_HASH_SIZE - 1.  However, the hash saved in a socket
    varies depending on its address type; sockets with BSD addresses always
    have UNIX_HASH_SIZE in their unix_sk(sk)->addr->hash.

    This is just for the UNIX_ABSTRACT() macro used to check the address type.
    The difference of the saved hashes comes from the first byte of the address
    in the first place.  So, we can test it directly.

    Then we can keep a real hash in each socket and replace unix_table_lock
    with per-hash locks in the later patch.

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 237d5ec9f584ec69c1dbfd20106076adf9e483d3
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:26 2021 +0900

    af_unix: Allocate unix_address in unix_bind_(bsd|abstract)().

    To terminate address with '\0' in unix_bind_bsd(), we add
    unix_create_addr() and call it in unix_bind_bsd() and unix_bind_abstract().

    Also, unix_bind_abstract() does not return -EEXIST.  Only
    kern_path_create() and vfs_mknod() in unix_bind_bsd() can return it,
    so we move the last error check in unix_bind() to unix_bind_bsd().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 2f98fa0b3b63e8d10d1022491e331a7f05479ae9
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:25 2021 +0900

    af_unix: Remove unix_mkname().

    This patch removes unix_mkname() and postpones calculating a hash to
    unix_bind_abstract().  Some BSD stuffs still remain in unix_bind()
    though, the next patch packs them into unix_bind_bsd().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 0a0c8192a4b8a56d07b7686a01e27dd73e12e351
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:24 2021 +0900

    af_unix: Copy unix_mkname() into unix_find_(bsd|abstract)().

    We should not call unix_mkname() before unix_find_other() and instead do
    the same thing where necessary based on the address type:

      - terminating the address with '\0' in unix_find_bsd()
      - calculating the hash in unix_find_abstract().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 061f2f340fc35259771e469762b39efbae7f21f9
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:23 2021 +0900

    af_unix: Cut unix_validate_addr() out of unix_mkname().

    unix_mkname() tests socket address length and family and does some
    processing based on the address type.  It is called in the early stage,
    and therefore some instructions are redundant and can end up in vain.

    The address length/family tests are done twice in unix_bind().  Also, the
    address type is rechecked later in unix_bind() and unix_find_other(), where
    we can do the same processing.  Moreover, in the BSD address case, the hash
    is set to 0 but never used and confusing.

    This patch moves the address tests out of unix_mkname(), and the following
    patches move the other part into appropriate places and remove
    unix_mkname() finally.

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit b4365eac7e478d826d1d62e8144cac3b5d894c5e
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:22 2021 +0900

    af_unix: Return an error as a pointer in unix_find_other().

    We can return an error as a pointer and need not pass an additional
    argument to unix_find_other().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit db43d103e5a3399b23e53076edc1f4b0aaa960c0
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:21 2021 +0900

    af_unix: Factorise unix_find_other() based on address types.

    As done in the commit fa42d910a38e ("unix_bind(): take BSD and abstract
    address cases into new helpers"), this patch moves BSD and abstract address
    cases from unix_find_other() into unix_find_bsd() and unix_find_abstract().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 15b2298c71e248fd7ff8b524e42dd0b99d968cc6
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:20 2021 +0900

    af_unix: Pass struct sock to unix_autobind().

    We do not use struct socket in unix_autobind() and pass struct sock to
    unix_bind_bsd() and unix_bind_abstract().  Let's pass it to unix_autobind()
    as well.

    Also, this patch fixes these errors by checkpatch.pl.

      ERROR: do not use assignment in if condition
      #1795: FILE: net/unix/af_unix.c:1795:
      +	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr

      CHECK: Logical continuations should be on the previous line
      #1796: FILE: net/unix/af_unix.c:1796:
      +	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
      +	    && (err = unix_autobind(sock)) != 0)

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>

commit 899b11ff205f78fa78cd4070e905486f07cc709f
Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Date:   Wed Nov 24 11:14:19 2021 +0900

    af_unix: Use offsetof() instead of sizeof().

    The length of the AF_UNIX socket address contains an offset to the member
    sun_path of struct sockaddr_un.

    Currently, the preceding member is just sun_family, and its type is
    sa_family_t and resolved to short.  Therefore, the offset is represented by
    sizeof(short).  However, it is not clear and fragile to changes in struct
    sockaddr_storage or sockaddr_un.

    This commit makes it clear and robust by rewriting sizeof() with
    offsetof().

    Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
---
 include/net/af_unix.h                         |   3 +-
 net/unix/af_unix.c                            | 577 ++++++++++--------
 net/unix/diag.c                               |  23 +-
 .../selftests/bpf/progs/bpf_iter_unix.c       |   2 +-
 .../selftests/bpf/progs/bpf_tracing_net.h     |   2 -
 .../bpf/progs/test_skc_to_unix_sock.c         |   2 +-
 6 files changed, 351 insertions(+), 258 deletions(-)

diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 7d142e8a0550..a7ef624ed726 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -20,13 +20,12 @@ struct sock *unix_peer_get(struct sock *sk);
 #define UNIX_HASH_BITS	8
 
 extern unsigned int unix_tot_inflight;
-extern spinlock_t unix_table_lock;
+extern spinlock_t unix_table_locks[2 * UNIX_HASH_SIZE];
 extern struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
 
 struct unix_address {
 	refcount_t	refcnt;
 	int		len;
-	unsigned int	hash;
 	struct sockaddr_un name[];
 };
 
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index b0bfc78e421c..d799c62a1f79 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -117,24 +117,64 @@
 
 #include "scm.h"
 
+spinlock_t unix_table_locks[2 * UNIX_HASH_SIZE];
+EXPORT_SYMBOL_GPL(unix_table_locks);
 struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
 EXPORT_SYMBOL_GPL(unix_socket_table);
-DEFINE_SPINLOCK(unix_table_lock);
-EXPORT_SYMBOL_GPL(unix_table_lock);
 static atomic_long_t unix_nr_socks;
 
+/* SMP locking strategy:
+ *    hash table is protected with spinlock unix_table_locks
+ *    each socket state is protected by separate spin lock.
+ */
 
-static struct hlist_head *unix_sockets_unbound(void *addr)
+static unsigned int unix_unbound_hash(struct sock *sk)
 {
-	unsigned long hash = (unsigned long)addr;
+	unsigned long hash = (unsigned long)sk;
 
 	hash ^= hash >> 16;
 	hash ^= hash >> 8;
-	hash %= UNIX_HASH_SIZE;
-	return &unix_socket_table[UNIX_HASH_SIZE + hash];
+	hash ^= sk->sk_type;
+
+	return UNIX_HASH_SIZE + (hash & (UNIX_HASH_SIZE - 1));
 }
 
-#define UNIX_ABSTRACT(sk)	(unix_sk(sk)->addr->hash < UNIX_HASH_SIZE)
+static unsigned int unix_bsd_hash(struct inode *i)
+{
+	return i->i_ino & (UNIX_HASH_SIZE - 1);
+}
+
+static unsigned int unix_abstract_hash(struct sockaddr_un *sunaddr,
+				       int addr_len, int type)
+{
+	__wsum csum = csum_partial(sunaddr, addr_len, 0);
+	unsigned int hash;
+
+	hash = (__force unsigned int)csum_fold(csum);
+	hash ^= hash >> 8;
+	hash ^= type;
+
+	return hash & (UNIX_HASH_SIZE - 1);
+}
+
+static void unix_table_double_lock(unsigned int hash1, unsigned int hash2)
+{
+	/* hash1 and hash2 is never the same because
+	 * one is between 0 and UNIX_HASH_SIZE - 1, and
+	 * another is between UNIX_HASH_SIZE and UNIX_HASH_SIZE * 2.
+	 */
+	if (hash1 > hash2)
+		swap(hash1, hash2);
+
+	spin_lock(&unix_table_locks[hash1]);
+	spin_lock_nested(&unix_table_locks[hash2], SINGLE_DEPTH_NESTING);
+}
+
+static void unix_table_double_unlock(unsigned int hash1, unsigned int hash2)
+{
+	spin_unlock(&unix_table_locks[hash1]);
+	spin_unlock(&unix_table_locks[hash2]);
+}
 
 #ifdef CONFIG_SECURITY_NETWORK
 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
@@ -164,20 +204,6 @@ static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
 }
 #endif /* CONFIG_SECURITY_NETWORK */
 
-/*
- *  SMP locking strategy:
- *    hash table is protected with spinlock unix_table_lock
- *    each socket state is protected by separate spin lock.
- */
-
-static inline unsigned int unix_hash_fold(__wsum n)
-{
-	unsigned int hash = (__force unsigned int)csum_fold(n);
-
-	hash ^= hash>>8;
-	return hash&(UNIX_HASH_SIZE-1);
-}
-
 #define unix_peer(sk) (unix_sk(sk)->peer)
 
 static inline int unix_our_peer(struct sock *sk, struct sock *osk)
@@ -214,6 +240,22 @@ struct sock *unix_peer_get(struct sock *s)
 }
 EXPORT_SYMBOL_GPL(unix_peer_get);
 
+static struct unix_address *unix_create_addr(struct sockaddr_un *sunaddr,
+					     int addr_len)
+{
+	struct unix_address *addr;
+
+	addr = kmalloc(sizeof(*addr) + addr_len, GFP_KERNEL);
+	if (!addr)
+		return NULL;
+
+	refcount_set(&addr->refcnt, 1);
+	addr->len = addr_len;
+	memcpy(addr->name, sunaddr, addr_len);
+
+	return addr;
+}
+
 static inline void unix_release_addr(struct unix_address *addr)
 {
 	if (refcount_dec_and_test(&addr->refcnt))
@@ -227,29 +269,29 @@ static inline void unix_release_addr(struct unix_address *addr)
  *		- if started by zero, it is abstract name.
  */
 
-static int unix_mkname(struct sockaddr_un *sunaddr, int len, unsigned int *hashp)
+static int unix_validate_addr(struct sockaddr_un *sunaddr, int addr_len)
 {
-	*hashp = 0;
-
-	if (len <= sizeof(short) || len > sizeof(*sunaddr))
+	if (addr_len <= offsetof(struct sockaddr_un, sun_path) ||
+	    addr_len > sizeof(*sunaddr))
 		return -EINVAL;
-	if (!sunaddr || sunaddr->sun_family != AF_UNIX)
-		return -EINVAL;
-	if (sunaddr->sun_path[0]) {
-		/*
-		 * This may look like an off by one error but it is a bit more
-		 * subtle. 108 is the longest valid AF_UNIX path for a binding.
-		 * sun_path[108] doesn't as such exist.  However in kernel space
-		 * we are guaranteed that it is a valid memory location in our
-		 * kernel address buffer.
-		 */
-		((char *)sunaddr)[len] = 0;
-		len = strlen(sunaddr->sun_path)+1+sizeof(short);
-		return len;
-	}
 
-	*hashp = unix_hash_fold(csum_partial(sunaddr, len, 0));
-	return len;
+	if (sunaddr->sun_family != AF_UNIX)
+		return -EINVAL;
+
+	return 0;
+}
+
+static void unix_mkname_bsd(struct sockaddr_un *sunaddr, int addr_len)
+{
+	/* This may look like an off by one error but it is a bit more
+	 * subtle.  108 is the longest valid AF_UNIX path for a binding.
+	 * sun_path[108] doesn't as such exist.  However in kernel space
+	 * we are guaranteed that it is a valid memory location in our
+	 * kernel address buffer because syscall functions always pass
+	 * a pointer of struct sockaddr_storage which has a bigger buffer
+	 * than 108.
+	 */
+	((char *)sunaddr)[addr_len] = 0;
 }
 
 static void __unix_remove_socket(struct sock *sk)
@@ -257,32 +299,34 @@ static void __unix_remove_socket(struct sock *sk)
 	sk_del_node_init(sk);
 }
 
-static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
+static void __unix_insert_socket(struct sock *sk)
 {
 	WARN_ON(!sk_unhashed(sk));
-	sk_add_node(sk, list);
+	sk_add_node(sk, &unix_socket_table[sk->sk_hash]);
 }
 
-static void __unix_set_addr(struct sock *sk, struct unix_address *addr,
-			    unsigned hash)
+static void __unix_set_addr_hash(struct sock *sk, struct unix_address *addr,
+				 unsigned int hash)
 {
 	__unix_remove_socket(sk);
 	smp_store_release(&unix_sk(sk)->addr, addr);
-	__unix_insert_socket(&unix_socket_table[hash], sk);
+
+	sk->sk_hash = hash;
+	__unix_insert_socket(sk);
 }
 
-static inline void unix_remove_socket(struct sock *sk)
+static void unix_remove_socket(struct sock *sk)
 {
-	spin_lock(&unix_table_lock);
+	spin_lock(&unix_table_locks[sk->sk_hash]);
 	__unix_remove_socket(sk);
-	spin_unlock(&unix_table_lock);
+	spin_unlock(&unix_table_locks[sk->sk_hash]);
 }
 
-static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
+static void unix_insert_unbound_socket(struct sock *sk)
 {
-	spin_lock(&unix_table_lock);
-	__unix_insert_socket(list, sk);
-	spin_unlock(&unix_table_lock);
+	spin_lock(&unix_table_locks[sk->sk_hash]);
+	__unix_insert_socket(sk);
+	spin_unlock(&unix_table_locks[sk->sk_hash]);
 }
 
 static struct sock *__unix_find_socket_byname(struct net *net,
@@ -310,32 +354,31 @@ static inline struct sock *unix_find_socket_byname(struct net *net,
 {
 	struct sock *s;
 
-	spin_lock(&unix_table_lock);
+	spin_lock(&unix_table_locks[hash]);
 	s = __unix_find_socket_byname(net, sunname, len, hash);
 	if (s)
 		sock_hold(s);
-	spin_unlock(&unix_table_lock);
+	spin_unlock(&unix_table_locks[hash]);
 	return s;
 }
 
 static struct sock *unix_find_socket_byinode(struct inode *i)
 {
+	unsigned int hash = unix_bsd_hash(i);
 	struct sock *s;
 
-	spin_lock(&unix_table_lock);
-	sk_for_each(s,
-		    &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
+	spin_lock(&unix_table_locks[hash]);
+	sk_for_each(s, &unix_socket_table[hash]) {
 		struct dentry *dentry = unix_sk(s)->path.dentry;
 
 		if (dentry && d_backing_inode(dentry) == i) {
 			sock_hold(s);
-			goto found;
+			spin_unlock(&unix_table_locks[hash]);
+			return s;
 		}
 	}
-	s = NULL;
-found:
-	spin_unlock(&unix_table_lock);
-	return s;
+	spin_unlock(&unix_table_locks[hash]);
+	return NULL;
 }
 
 /* Support code for asymmetrically connected dgram sockets
@@ -872,6 +915,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern,
 
 	sock_init_data(sock, sk);
 
+	sk->sk_hash		= unix_unbound_hash(sk);
 	sk->sk_allocation	= GFP_KERNEL_ACCOUNT;
 	sk->sk_write_space	= unix_write_space;
 	sk->sk_max_ack_backlog	= net->unx.sysctl_max_dgram_qlen;
@@ -887,7 +931,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern,
 	init_waitqueue_head(&u->peer_wait);
 	init_waitqueue_func_entry(&u->peer_wake, unix_dgram_peer_wake_relay);
 	memset(&u->scm_stat, 0, sizeof(struct scm_stat));
-	unix_insert_socket(unix_sockets_unbound(sk), sk);
+	unix_insert_unbound_socket(sk);
 
 	local_bh_disable();
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
@@ -952,15 +996,90 @@ static int unix_release(struct socket *sock)
 	return 0;
 }
 
-static int unix_autobind(struct socket *sock)
+static struct sock *unix_find_bsd(struct net *net, struct sockaddr_un *sunaddr,
+				  int addr_len, int type)
 {
-	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
-	struct unix_sock *u = unix_sk(sk);
-	static u32 ordernum = 1;
-	struct unix_address *addr;
+	struct inode *inode;
+	struct path path;
+	struct sock *sk;
+	int err;
+
+	unix_mkname_bsd(sunaddr, addr_len);
+	err = kern_path(sunaddr->sun_path, LOOKUP_FOLLOW, &path);
+	if (err)
+		goto fail;
+
+	err = path_permission(&path, MAY_WRITE);
+	if (err)
+		goto path_put;
+
+	err = -ECONNREFUSED;
+	inode = d_backing_inode(path.dentry);
+	if (!S_ISSOCK(inode->i_mode))
+		goto path_put;
+
+	sk = unix_find_socket_byinode(inode);
+	if (!sk)
+		goto path_put;
+
+	err = -EPROTOTYPE;
+	if (sk->sk_type == type)
+		touch_atime(&path);
+	else
+		goto sock_put;
+
+	path_put(&path);
+
+	return sk;
+
+sock_put:
+	sock_put(sk);
+path_put:
+	path_put(&path);
+fail:
+	return ERR_PTR(err);
+}
+
+static struct sock *unix_find_abstract(struct net *net,
+				       struct sockaddr_un *sunaddr,
+				       int addr_len, int type)
+{
+	unsigned int hash = unix_abstract_hash(sunaddr, addr_len, type);
+	struct dentry *dentry;
+	struct sock *sk;
+
+	sk = unix_find_socket_byname(net, sunaddr, addr_len, hash);
+	if (!sk)
+		return ERR_PTR(-ECONNREFUSED);
+
+	dentry = unix_sk(sk)->path.dentry;
+	if (dentry)
+		touch_atime(&unix_sk(sk)->path);
+
+	return sk;
+}
+
+static struct sock *unix_find_other(struct net *net,
+				    struct sockaddr_un *sunaddr,
+				    int addr_len, int type)
+{
+	struct sock *sk;
+
+	if (sunaddr->sun_path[0])
+		sk = unix_find_bsd(net, sunaddr, addr_len, type);
+	else
+		sk = unix_find_abstract(net, sunaddr, addr_len, type);
+
+	return sk;
+}
+
+static int unix_autobind(struct sock *sk)
+{
+	unsigned int new_hash, old_hash = sk->sk_hash;
+	struct unix_sock *u = unix_sk(sk);
+	struct unix_address *addr;
+	u32 lastnum, ordernum;
 	int err;
-	unsigned int retries = 0;
 
 	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
@@ -970,141 +1089,103 @@ static int unix_autobind(struct socket *sock)
 		goto out;
 
 	err = -ENOMEM;
-	addr = kzalloc(sizeof(*addr) + sizeof(short) + 16, GFP_KERNEL);
+	addr = kzalloc(sizeof(*addr) +
+		       offsetof(struct sockaddr_un, sun_path) + 16, GFP_KERNEL);
 	if (!addr)
 		goto out;
 
+	addr->len = offsetof(struct sockaddr_un, sun_path) + 6;
 	addr->name->sun_family = AF_UNIX;
 	refcount_set(&addr->refcnt, 1);
 
+	ordernum = prandom_u32();
+	lastnum = ordernum & 0xFFFFF;
 retry:
-	addr->len = sprintf(addr->name->sun_path+1, "%05x", ordernum) + 1 + sizeof(short);
-	addr->hash = unix_hash_fold(csum_partial(addr->name, addr->len, 0));
-	addr->hash ^= sk->sk_type;
+	ordernum = (ordernum + 1) & 0xFFFFF;
+	sprintf(addr->name->sun_path + 1, "%05x", ordernum);
 
-	spin_lock(&unix_table_lock);
-	ordernum = (ordernum+1)&0xFFFFF;
+	new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type);
+	unix_table_double_lock(old_hash, new_hash);
 
-	if (__unix_find_socket_byname(net, addr->name, addr->len, addr->hash)) {
-		spin_unlock(&unix_table_lock);
-		/*
-		 * __unix_find_socket_byname() may take long time if many names
+	if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
+				      new_hash)) {
+		unix_table_double_unlock(old_hash, new_hash);
+
+		/* __unix_find_socket_byname() may take long time if many names
 		 * are already in use.
 		 */
 		cond_resched();
-		/* Give up if all names seems to be in use. */
-		if (retries++ == 0xFFFFF) {
+
+		if (ordernum == lastnum) {
+			/* Give up if all names seems to be in use. */
 			err = -ENOSPC;
-			kfree(addr);
+			unix_release_addr(addr);
 			goto out;
 		}
+
 		goto retry;
 	}
 
-	__unix_set_addr(sk, addr, addr->hash);
-	spin_unlock(&unix_table_lock);
+	__unix_set_addr_hash(sk, addr, new_hash);
+	unix_table_double_unlock(old_hash, new_hash);
 	err = 0;
 
 out:	mutex_unlock(&u->bindlock);
 	return err;
 }
 
-static struct sock *unix_find_other(struct net *net,
-				    struct sockaddr_un *sunname, int len,
-				    int type, unsigned int hash, int *error)
+static int unix_bind_bsd(struct sock *sk, struct sockaddr_un *sunaddr,
+			 int addr_len)
 {
-	struct sock *u;
-	struct path path;
-	int err = 0;
-
-	if (sunname->sun_path[0]) {
-		struct inode *inode;
-		err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
-		if (err)
-			goto fail;
-		inode = d_backing_inode(path.dentry);
-		err = path_permission(&path, MAY_WRITE);
-		if (err)
-			goto put_fail;
-
-		err = -ECONNREFUSED;
-		if (!S_ISSOCK(inode->i_mode))
-			goto put_fail;
-		u = unix_find_socket_byinode(inode);
-		if (!u)
-			goto put_fail;
-
-		if (u->sk_type == type)
-			touch_atime(&path);
-
-		path_put(&path);
-
-		err = -EPROTOTYPE;
-		if (u->sk_type != type) {
-			sock_put(u);
-			goto fail;
-		}
-	} else {
-		err = -ECONNREFUSED;
-		u = unix_find_socket_byname(net, sunname, len, type ^ hash);
-		if (u) {
-			struct dentry *dentry;
-			dentry = unix_sk(u)->path.dentry;
-			if (dentry)
-				touch_atime(&unix_sk(u)->path);
-		} else
-			goto fail;
-	}
-	return u;
-
-put_fail:
-	path_put(&path);
-fail:
-	*error = err;
-	return NULL;
-}
-
-static int unix_bind_bsd(struct sock *sk, struct unix_address *addr)
-{
-	struct unix_sock *u = unix_sk(sk);
 	umode_t mode = S_IFSOCK |
 	       (SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask());
+	unsigned int new_hash, old_hash = sk->sk_hash;
+	struct unix_sock *u = unix_sk(sk);
 	struct user_namespace *ns; // barf...
-	struct path parent;
+	struct unix_address *addr;
 	struct dentry *dentry;
-	unsigned int hash;
+	struct path parent;
 	int err;
 
+	unix_mkname_bsd(sunaddr, addr_len);
+	addr_len = strlen(sunaddr->sun_path) +
+		offsetof(struct sockaddr_un, sun_path) + 1;
+
+	addr = unix_create_addr(sunaddr, addr_len);
+	if (!addr)
+		return -ENOMEM;
+
 	/*
 	 * Get the parent directory, calculate the hash for last
 	 * component.
 	 */
 	dentry = kern_path_create(AT_FDCWD, addr->name->sun_path, &parent, 0);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
-	ns = mnt_user_ns(parent.mnt);
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
+		goto out;
+	}
 
 	/*
 	 * All right, let's create it.
 	 */
+	ns = mnt_user_ns(parent.mnt);
 	err = security_path_mknod(&parent, dentry, mode, 0);
 	if (!err)
 		err = vfs_mknod(ns, d_inode(parent.dentry), dentry, mode, 0);
 	if (err)
-		goto out;
+		goto out_path;
 	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
 		goto out_unlink;
 	if (u->addr)
 		goto out_unlock;
 
-	addr->hash = UNIX_HASH_SIZE;
-	hash = d_backing_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
-	spin_lock(&unix_table_lock);
+	new_hash = unix_bsd_hash(d_backing_inode(dentry));
+	unix_table_double_lock(old_hash, new_hash);
 	u->path.mnt = mntget(parent.mnt);
 	u->path.dentry = dget(dentry);
-	__unix_set_addr(sk, addr, hash);
-	spin_unlock(&unix_table_lock);
+	__unix_set_addr_hash(sk, addr, new_hash);
+	unix_table_double_unlock(old_hash, new_hash);
 	mutex_unlock(&u->bindlock);
 	done_path_create(&parent, dentry);
 	return 0;
@@ -1115,74 +1196,76 @@ static int unix_bind_bsd(struct sock *sk, struct unix_address *addr)
 out_unlink:
 	/* failed after successful mknod?  unlink what we'd created... */
 	vfs_unlink(ns, d_inode(parent.dentry), dentry, NULL);
-out:
+out_path:
 	done_path_create(&parent, dentry);
-	return err;
+out:
+	unix_release_addr(addr);
+	return err == -EEXIST ? -EADDRINUSE : err;
 }
 
-static int unix_bind_abstract(struct sock *sk, struct unix_address *addr)
+static int unix_bind_abstract(struct sock *sk, struct sockaddr_un *sunaddr,
+			      int addr_len)
 {
+	unsigned int new_hash, old_hash = sk->sk_hash;
 	struct unix_sock *u = unix_sk(sk);
+	struct unix_address *addr;
 	int err;
 
+	addr = unix_create_addr(sunaddr, addr_len);
+	if (!addr)
+		return -ENOMEM;
+
 	err = mutex_lock_interruptible(&u->bindlock);
 	if (err)
-		return err;
+		goto out;
 
 	if (u->addr) {
-		mutex_unlock(&u->bindlock);
-		return -EINVAL;
+		err = -EINVAL;
+		goto out_mutex;
 	}
 
-	spin_lock(&unix_table_lock);
+	new_hash = unix_abstract_hash(addr->name, addr->len, sk->sk_type);
+	unix_table_double_lock(old_hash, new_hash);
+
 	if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
-				      addr->hash)) {
-		spin_unlock(&unix_table_lock);
-		mutex_unlock(&u->bindlock);
-		return -EADDRINUSE;
-	}
-	__unix_set_addr(sk, addr, addr->hash);
-	spin_unlock(&unix_table_lock);
+				      new_hash))
+		goto out_spin;
+
+	__unix_set_addr_hash(sk, addr, new_hash);
+	unix_table_double_unlock(old_hash, new_hash);
 	mutex_unlock(&u->bindlock);
 	return 0;
+
+out_spin:
+	unix_table_double_unlock(old_hash, new_hash);
+	err = -EADDRINUSE;
+out_mutex:
+	mutex_unlock(&u->bindlock);
+out:
+	unix_release_addr(addr);
+	return err;
 }
 
 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
-	struct sock *sk = sock->sk;
 	struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
-	char *sun_path = sunaddr->sun_path;
+	struct sock *sk = sock->sk;
 	int err;
-	unsigned int hash;
-	struct unix_address *addr;
 
-	if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
-	    sunaddr->sun_family != AF_UNIX)
-		return -EINVAL;
+	if (addr_len == offsetof(struct sockaddr_un, sun_path) &&
+	    sunaddr->sun_family == AF_UNIX)
+		return unix_autobind(sk);
 
-	if (addr_len == sizeof(short))
-		return unix_autobind(sock);
-
-	err = unix_mkname(sunaddr, addr_len, &hash);
-	if (err < 0)
-		return err;
-	addr_len = err;
-	addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
-	if (!addr)
-		return -ENOMEM;
-
-	memcpy(addr->name, sunaddr, addr_len);
-	addr->len = addr_len;
-	addr->hash = hash ^ sk->sk_type;
-	refcount_set(&addr->refcnt, 1);
-
-	if (sun_path[0])
-		err = unix_bind_bsd(sk, addr);
-	else
-		err = unix_bind_abstract(sk, addr);
+	err = unix_validate_addr(sunaddr, addr_len);
 	if (err)
-		unix_release_addr(addr);
-	return err == -EEXIST ? -EADDRINUSE : err;
+		return err;
+
+	if (sunaddr->sun_path[0])
+		err = unix_bind_bsd(sk, sunaddr, addr_len);
+	else
+		err = unix_bind_abstract(sk, sunaddr, addr_len);
+
+	return err;
 }
 
 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
@@ -1217,7 +1300,6 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 	struct net *net = sock_net(sk);
 	struct sockaddr_un *sunaddr = (struct sockaddr_un *)addr;
 	struct sock *other;
-	unsigned int hash;
 	int err;
 
 	err = -EINVAL;
@@ -1225,19 +1307,23 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
 		goto out;
 
 	if (addr->sa_family != AF_UNSPEC) {
-		err = unix_mkname(sunaddr, alen, &hash);
-		if (err < 0)
+		err = unix_validate_addr(sunaddr, alen);
+		if (err)
 			goto out;
-		alen = err;
 
 		if (test_bit(SOCK_PASSCRED, &sock->flags) &&
-		    !unix_sk(sk)->addr && (err = unix_autobind(sock)) != 0)
-			goto out;
+		    !unix_sk(sk)->addr) {
+			err = unix_autobind(sk);
+			if (err)
+				goto out;
+		}
 
 restart:
-		other = unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
-		if (!other)
+		other = unix_find_other(net, sunaddr, alen, sock->type);
+		if (IS_ERR(other)) {
+			err = PTR_ERR(other);
 			goto out;
+		}
 
 		unix_state_double_lock(sk, other);
 
@@ -1327,19 +1413,19 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 	struct sock *newsk = NULL;
 	struct sock *other = NULL;
 	struct sk_buff *skb = NULL;
-	unsigned int hash;
 	int st;
 	int err;
 	long timeo;
 
-	err = unix_mkname(sunaddr, addr_len, &hash);
-	if (err < 0)
+	err = unix_validate_addr(sunaddr, addr_len);
+	if (err)
 		goto out;
-	addr_len = err;
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr &&
-	    (err = unix_autobind(sock)) != 0)
-		goto out;
+	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
+		err = unix_autobind(sk);
+		if (err)
+			goto out;
+	}
 
 	timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 
@@ -1365,9 +1451,12 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 
 restart:
 	/*  Find listening sock. */
-	other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
-	if (!other)
+	other = unix_find_other(net, sunaddr, addr_len, sk->sk_type);
+	if (IS_ERR(other)) {
+		err = PTR_ERR(other);
+		other = NULL;
 		goto out;
+	}
 
 	/* Latch state of peer */
 	unix_state_lock(other);
@@ -1455,9 +1544,9 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
 	 *
 	 * The contents of *(otheru->addr) and otheru->path
 	 * are seen fully set up here, since we have found
-	 * otheru in hash under unix_table_lock.  Insertion
+	 * otheru in hash under unix_table_locks.  Insertion
 	 * into the hash chain we'd found it in had been done
-	 * in an earlier critical area protected by unix_table_lock,
+	 * in an earlier critical area protected by unix_table_locks,
 	 * the same one where we'd set *(otheru->addr) contents,
 	 * as well as otheru->path and otheru->addr itself.
 	 *
@@ -1604,7 +1693,7 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
 	if (!addr) {
 		sunaddr->sun_family = AF_UNIX;
 		sunaddr->sun_path[0] = 0;
-		err = sizeof(short);
+		err = offsetof(struct sockaddr_un, sun_path);
 	} else {
 		err = addr->len;
 		memcpy(sunaddr, addr->name, addr->len);
@@ -1760,9 +1849,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 	struct unix_sock *u = unix_sk(sk);
 	DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
 	struct sock *other = NULL;
-	int namelen = 0; /* fake GCC */
 	int err;
-	unsigned int hash;
 	struct sk_buff *skb;
 	long timeo;
 	struct scm_cookie scm;
@@ -1779,10 +1866,9 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 		goto out;
 
 	if (msg->msg_namelen) {
-		err = unix_mkname(sunaddr, msg->msg_namelen, &hash);
-		if (err < 0)
+		err = unix_validate_addr(sunaddr, msg->msg_namelen);
+		if (err)
 			goto out;
-		namelen = err;
 	} else {
 		sunaddr = NULL;
 		err = -ENOTCONN;
@@ -1791,9 +1877,11 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 			goto out;
 	}
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr
-	    && (err = unix_autobind(sock)) != 0)
-		goto out;
+	if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) {
+		err = unix_autobind(sk);
+		if (err)
+			goto out;
+	}
 
 	err = -EMSGSIZE;
 	if (len > sk->sk_sndbuf - 32)
@@ -1833,10 +1921,13 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
 		if (sunaddr == NULL)
 			goto out_free;
 
-		other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
-					hash, &err);
-		if (other == NULL)
+		other = unix_find_other(net, sunaddr, msg->msg_namelen,
+					sk->sk_type);
+		if (IS_ERR(other)) {
+			err = PTR_ERR(other);
+			other = NULL;
 			goto out_free;
+		}
 	}
 
 	if (sk_filter(other, skb) < 0) {
@@ -3132,7 +3223,7 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock,
 #define BUCKET_SPACE (BITS_PER_LONG - (UNIX_HASH_BITS + 1) - 1)
 
 #define get_bucket(x) ((x) >> BUCKET_SPACE)
-#define get_offset(x) ((x) & ((1L << BUCKET_SPACE) - 1))
+#define get_offset(x) ((x) & ((1UL << BUCKET_SPACE) - 1))
 #define set_bucket_offset(b, o) ((b) << BUCKET_SPACE | (o))
 
 static struct sock *unix_from_bucket(struct seq_file *seq, loff_t *pos)
@@ -3156,7 +3247,7 @@ static struct sock *unix_next_socket(struct seq_file *seq,
 				     struct sock *sk,
 				     loff_t *pos)
 {
-	unsigned long bucket;
+	unsigned long bucket = get_bucket(*pos);
 
 	while (sk > (struct sock *)SEQ_START_TOKEN) {
 		sk = sk_next(sk);
@@ -3167,12 +3258,13 @@ static struct sock *unix_next_socket(struct seq_file *seq,
 	}
 
 	do {
+		spin_lock(&unix_table_locks[bucket]);
 		sk = unix_from_bucket(seq, pos);
 		if (sk)
 			return sk;
 
 next_bucket:
-		bucket = get_bucket(*pos) + 1;
+		spin_unlock(&unix_table_locks[bucket++]);
 		*pos = set_bucket_offset(bucket, 1);
 	} while (bucket < ARRAY_SIZE(unix_socket_table));
 
@@ -3180,10 +3272,7 @@ static struct sock *unix_next_socket(struct seq_file *seq,
 }
 
 static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
-	__acquires(unix_table_lock)
 {
-	spin_lock(&unix_table_lock);
-
 	if (!*pos)
 		return SEQ_START_TOKEN;
 
@@ -3200,9 +3289,11 @@ static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 }
 
 static void unix_seq_stop(struct seq_file *seq, void *v)
-	__releases(unix_table_lock)
 {
-	spin_unlock(&unix_table_lock);
+	struct sock *sk = v;
+
+	if (sk)
+		spin_unlock(&unix_table_locks[sk->sk_hash]);
 }
 
 static int unix_seq_show(struct seq_file *seq, void *v)
@@ -3227,15 +3318,16 @@ static int unix_seq_show(struct seq_file *seq, void *v)
 			(s->sk_state == TCP_ESTABLISHED ? SS_CONNECTING : SS_DISCONNECTING),
 			sock_i_ino(s));
 
-		if (u->addr) {	// under unix_table_lock here
+		if (u->addr) {	// under unix_table_locks here
 			int i, len;
 			seq_putc(seq, ' ');
 
 			i = 0;
-			len = u->addr->len - sizeof(short);
-			if (!UNIX_ABSTRACT(s))
+			len = u->addr->len -
+				offsetof(struct sockaddr_un, sun_path);
+			if (u->addr->name->sun_path[0]) {
 				len--;
-			else {
+			} else {
 				seq_putc(seq, '@');
 				i++;
 			}
@@ -3385,10 +3477,13 @@ static void __init bpf_iter_register(void)
 
 static int __init af_unix_init(void)
 {
-	int rc = -1;
+	int i, rc = -1;
 
 	BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof_field(struct sk_buff, cb));
 
+	for (i = 0; i < 2 * UNIX_HASH_SIZE; i++)
+		spin_lock_init(&unix_table_locks[i]);
+
 	rc = proto_register(&unix_dgram_proto, 1);
 	if (rc != 0) {
 		pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
diff --git a/net/unix/diag.c b/net/unix/diag.c
index 7e7d7f45685a..bb0b5ea1655f 100644
--- a/net/unix/diag.c
+++ b/net/unix/diag.c
@@ -13,13 +13,14 @@
 
 static int sk_diag_dump_name(struct sock *sk, struct sk_buff *nlskb)
 {
-	/* might or might not have unix_table_lock */
+	/* might or might not have unix_table_locks */
 	struct unix_address *addr = smp_load_acquire(&unix_sk(sk)->addr);
 
 	if (!addr)
 		return 0;
 
-	return nla_put(nlskb, UNIX_DIAG_NAME, addr->len - sizeof(short),
+	return nla_put(nlskb, UNIX_DIAG_NAME,
+		       addr->len - offsetof(struct sockaddr_un, sun_path),
 		       addr->name->sun_path);
 }
 
@@ -203,13 +204,13 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 	s_slot = cb->args[0];
 	num = s_num = cb->args[1];
 
-	spin_lock(&unix_table_lock);
 	for (slot = s_slot;
 	     slot < ARRAY_SIZE(unix_socket_table);
 	     s_num = 0, slot++) {
 		struct sock *sk;
 
 		num = 0;
+		spin_lock(&unix_table_locks[slot]);
 		sk_for_each(sk, &unix_socket_table[slot]) {
 			if (!net_eq(sock_net(sk), net))
 				continue;
@@ -220,14 +221,16 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 			if (sk_diag_dump(sk, skb, req,
 					 NETLINK_CB(cb->skb).portid,
 					 cb->nlh->nlmsg_seq,
-					 NLM_F_MULTI) < 0)
+					 NLM_F_MULTI) < 0) {
+				spin_unlock(&unix_table_locks[slot]);
 				goto done;
+			}
 next:
 			num++;
 		}
+		spin_unlock(&unix_table_locks[slot]);
 	}
 done:
-	spin_unlock(&unix_table_lock);
 	cb->args[0] = slot;
 	cb->args[1] = num;
 
@@ -236,21 +239,19 @@ static int unix_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 
 static struct sock *unix_lookup_by_ino(unsigned int ino)
 {
-	int i;
 	struct sock *sk;
+	int i;
 
-	spin_lock(&unix_table_lock);
 	for (i = 0; i < ARRAY_SIZE(unix_socket_table); i++) {
+		spin_lock(&unix_table_locks[i]);
 		sk_for_each(sk, &unix_socket_table[i])
 			if (ino == sock_i_ino(sk)) {
 				sock_hold(sk);
-				spin_unlock(&unix_table_lock);
-
+				spin_unlock(&unix_table_locks[i]);
 				return sk;
 			}
+		spin_unlock(&unix_table_locks[i]);
 	}
-
-	spin_unlock(&unix_table_lock);
 	return NULL;
 }
 
diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_unix.c b/tools/testing/selftests/bpf/progs/bpf_iter_unix.c
index 94423902685d..c21e3f545371 100644
--- a/tools/testing/selftests/bpf/progs/bpf_iter_unix.c
+++ b/tools/testing/selftests/bpf/progs/bpf_iter_unix.c
@@ -49,7 +49,7 @@ int dump_unix(struct bpf_iter__unix *ctx)
 		       sock_i_ino(sk));
 
 	if (unix_sk->addr) {
-		if (!UNIX_ABSTRACT(unix_sk)) {
+		if (unix_sk->addr->name->sun_path[0]) {
 			BPF_SEQ_PRINTF(seq, " %s", unix_sk->addr->name->sun_path);
 		} else {
 			/* The name of the abstract UNIX domain socket starts
diff --git a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
index eef5646ddb19..e0f42601be9b 100644
--- a/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
+++ b/tools/testing/selftests/bpf/progs/bpf_tracing_net.h
@@ -6,8 +6,6 @@
 #define AF_INET6		10
 
 #define __SO_ACCEPTCON		(1 << 16)
-#define UNIX_HASH_SIZE		256
-#define UNIX_ABSTRACT(unix_sk)	(unix_sk->addr->hash < UNIX_HASH_SIZE)
 
 #define SOL_TCP			6
 #define TCP_CONGESTION		13
diff --git a/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c b/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c
index a408ec95cba4..eacda9fe07eb 100644
--- a/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c
+++ b/tools/testing/selftests/bpf/progs/test_skc_to_unix_sock.c
@@ -23,7 +23,7 @@ int BPF_PROG(unix_listen, struct socket *sock, int backlog)
 	if (!unix_sk)
 		return 0;
 
-	if (!UNIX_ABSTRACT(unix_sk))
+	if (unix_sk->addr->name->sun_path[0])
 		return 0;
 
 	len = unix_sk->addr->len - sizeof(short);
-- 
2.35.1