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From: Al Viro <viro@zeniv.linux.org.uk>
To: Denis Kirjanov <kda@linux-powerpc.org>
Cc: Christoph Hellwig <hch@infradead.org>,
	linux-kernel@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
	linux-fsdevel@vger.kernel.org
Subject: [PATCH 2/8] unix_bind(): allocate addr earlier
Date: Fri, 19 Feb 2021 04:20:38 +0000	[thread overview]
Message-ID: <YC88ln5Bhls27YqV@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <YC86WeSTkYZqRlJY@zeniv-ca.linux.org.uk>

From 24439dbb7b78cb301c73254b364020e6a3f31902 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 18 Feb 2021 15:52:53 -0500
Subject: [PATCH 2/8] unix_bind(): allocate addr earlier

makes it easier to massage; we do pay for that by extra work
(kmalloc+memcpy+kfree) in some error cases, but those are not
on the hot paths anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 net/unix/af_unix.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 179b4fe837e6..451d81f405c0 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1039,6 +1039,15 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	if (err < 0)
 		goto out;
 	addr_len = err;
+	err = -ENOMEM;
+	addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
+	if (!addr)
+		goto out;
+
+	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]) {
 		umode_t mode = S_IFSOCK |
@@ -1047,7 +1056,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		if (err) {
 			if (err == -EEXIST)
 				err = -EADDRINUSE;
-			goto out;
+			goto out_addr;
 		}
 	}
 
@@ -1059,16 +1068,6 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	if (u->addr)
 		goto out_up;
 
-	err = -ENOMEM;
-	addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
-	if (!addr)
-		goto out_up;
-
-	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]) {
 		addr->hash = UNIX_HASH_SIZE;
 		hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
@@ -1080,19 +1079,22 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		if (__unix_find_socket_byname(net, sunaddr, addr_len,
 					      sk->sk_type, hash)) {
 			spin_unlock(&unix_table_lock);
-			unix_release_addr(addr);
 			goto out_up;
 		}
 		hash = addr->hash;
 	}
 
 	__unix_set_addr(sk, addr, hash);
+	addr = NULL;
 	err = 0;
 out_up:
 	mutex_unlock(&u->bindlock);
 out_put:
 	if (err)
 		path_put(&path);
+out_addr:
+	if (addr)
+		unix_release_addr(addr);
 out:
 	return err;
 }
-- 
2.11.0


  parent reply	other threads:[~2021-02-19  4:21 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210125154937.26479-1-kda@linux-powerpc.org>
     [not found] ` <20210127175742.GA1744861@infradead.org>
     [not found]   ` <CAOJe8K0MC-TCURE2Gpci1SLnLXCbUkE7q6SS0fznzBA+Pf-B8Q@mail.gmail.com>
     [not found]     ` <20210129082524.GA2282796@infradead.org>
     [not found]       ` <CAOJe8K0iG91tm8YBRmE_rdMMMbc4iRsMGYNxJk0p9vEedNHEkg@mail.gmail.com>
     [not found]         ` <20210129131855.GA2346744@infradead.org>
2021-02-14 18:17           ` [PATCH] fs: export kern_path_locked Al Viro
2021-02-16 14:31             ` Denis Kirjanov
2021-02-16 18:00               ` Al Viro
2021-02-19  4:11                 ` Al Viro
2021-02-19  4:19                   ` [PATCH 1/8] af_unix: take address assignment/hash insertion into a new helper Al Viro
2021-02-20 19:12                     ` Cong Wang
2021-02-20 19:32                       ` Al Viro
2021-02-20 20:31                         ` Cong Wang
2021-02-20 21:08                           ` Al Viro
2021-02-22 19:06                             ` [PATCHSET] making unix_bind() undo mknod on failure Al Viro
2021-02-22 19:12                               ` [PATCH 1/8] af_unix: take address assignment/hash insertion into a new helper Al Viro
2021-02-22 19:12                                 ` [PATCH 2/8] unix_bind(): allocate addr earlier Al Viro
2021-02-22 19:12                                 ` [PATCH 3/8] unix_bind(): separate BSD and abstract cases Al Viro
2021-02-22 19:12                                 ` [PATCH 4/8] unix_bind(): take BSD and abstract address cases into new helpers Al Viro
2021-02-22 19:12                                 ` [PATCH 5/8] fold unix_mknod() into unix_bind_bsd() Al Viro
2021-02-22 19:12                                 ` [PATCH 6/8] unix_bind_bsd(): move done_path_create() call after dealing with ->bindlock Al Viro
2021-02-22 19:12                                 ` [PATCH 7/8] unix_bind_bsd(): unlink if we fail after successful mknod Al Viro
2021-02-22 19:12                                 ` [PATCH 8/8] __unix_find_socket_byname(): don't pass hash and type separately Al Viro
2021-02-22 19:12                               ` [PATCHSET] making unix_bind() undo mknod on failure Al Viro
2021-02-22 19:24                                 ` Al Viro
2021-02-24  0:40                               ` Jakub Kicinski
2021-02-19  4:20                   ` Al Viro [this message]
2021-02-19  4:21                   ` [PATCH 3/8] unix_bind(): separate BSD and abstract cases Al Viro
2021-02-19  4:21                   ` [PATCH 4/8] unix_bind(): take BSD and abstract address cases into new helpers Al Viro
2021-02-19  4:22                   ` [PATCH 5/8] fold unix_mknod() into unix_bind_bsd() Al Viro
2021-02-19  4:22                   ` [PATCH 6/8] unix_bind_bsd(): move done_path_create() call after dealing with ->bindlock Al Viro
2021-02-19  4:23                   ` [PATCH 7/8] unix_bind_bsd(): unlink if we fail after successful mknod Al Viro
2021-02-19  4:23                   ` [PATCH 8/8] __unix_find_socket_byname(): don't pass hash and type separately Al Viro

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