Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/socket.c b/net/socket.c
index 390a8ec..d7a1060 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * NET		An implementation of the SOCKET network access protocol.
  *
@@ -45,13 +46,6 @@
  *		Tigran Aivazian	:	Made listen(2) backlog sanity checks
  *					protocol-independent
  *
- *
- *		This program is free software; you can redistribute it and/or
- *		modify it under the terms of the GNU General Public License
- *		as published by the Free Software Foundation; either version
- *		2 of the License, or (at your option) any later version.
- *
- *
  *	This module is effectively the top level interface to the BSD socket
  *	paradigm.
  *
@@ -79,6 +73,7 @@
 #include <linux/module.h>
 #include <linux/highmem.h>
 #include <linux/mount.h>
+#include <linux/pseudo_fs.h>
 #include <linux/security.h>
 #include <linux/syscalls.h>
 #include <linux/compat.h>
@@ -90,6 +85,7 @@
 #include <linux/slab.h>
 #include <linux/xattr.h>
 #include <linux/nospec.h>
+#include <linux/indirect_call_wrapper.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -239,20 +235,13 @@
 static struct inode *sock_alloc_inode(struct super_block *sb)
 {
 	struct socket_alloc *ei;
-	struct socket_wq *wq;
 
 	ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
-	wq = kmalloc(sizeof(*wq), GFP_KERNEL);
-	if (!wq) {
-		kmem_cache_free(sock_inode_cachep, ei);
-		return NULL;
-	}
-	init_waitqueue_head(&wq->wait);
-	wq->fasync_list = NULL;
-	wq->flags = 0;
-	ei->socket.wq = wq;
+	init_waitqueue_head(&ei->socket.wq.wait);
+	ei->socket.wq.fasync_list = NULL;
+	ei->socket.wq.flags = 0;
 
 	ei->socket.state = SS_UNCONNECTED;
 	ei->socket.flags = 0;
@@ -263,12 +252,11 @@
 	return &ei->vfs_inode;
 }
 
-static void sock_destroy_inode(struct inode *inode)
+static void sock_free_inode(struct inode *inode)
 {
 	struct socket_alloc *ei;
 
 	ei = container_of(inode, struct socket_alloc, vfs_inode);
-	kfree_rcu(ei->socket.wq, rcu);
 	kmem_cache_free(sock_inode_cachep, ei);
 }
 
@@ -293,7 +281,7 @@
 
 static const struct super_operations sockfs_ops = {
 	.alloc_inode	= sock_alloc_inode,
-	.destroy_inode	= sock_destroy_inode,
+	.free_inode	= sock_free_inode,
 	.statfs		= simple_statfs,
 };
 
@@ -351,19 +339,22 @@
 	NULL
 };
 
-static struct dentry *sockfs_mount(struct file_system_type *fs_type,
-			 int flags, const char *dev_name, void *data)
+static int sockfs_init_fs_context(struct fs_context *fc)
 {
-	return mount_pseudo_xattr(fs_type, "socket:", &sockfs_ops,
-				  sockfs_xattr_handlers,
-				  &sockfs_dentry_operations, SOCKFS_MAGIC);
+	struct pseudo_fs_context *ctx = init_pseudo(fc, SOCKFS_MAGIC);
+	if (!ctx)
+		return -ENOMEM;
+	ctx->ops = &sockfs_ops;
+	ctx->dops = &sockfs_dentry_operations;
+	ctx->xattr = sockfs_xattr_handlers;
+	return 0;
 }
 
 static struct vfsmount *sock_mnt __read_mostly;
 
 static struct file_system_type sock_fs_type = {
 	.name =		"sockfs",
-	.mount =	sockfs_mount,
+	.init_fs_context = sockfs_init_fs_context,
 	.kill_sb =	kill_anon_super,
 };
 
@@ -384,6 +375,18 @@
  *	but we take care of internal coherence yet.
  */
 
+/**
+ *	sock_alloc_file - Bind a &socket to a &file
+ *	@sock: socket
+ *	@flags: file status flags
+ *	@dname: protocol name
+ *
+ *	Returns the &file bound with @sock, implicitly storing it
+ *	in sock->file. If dname is %NULL, sets to "".
+ *	On failure the return is a ERR pointer (see linux/err.h).
+ *	This function uses GFP_KERNEL internally.
+ */
+
 struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname)
 {
 	struct file *file;
@@ -415,7 +418,7 @@
 	}
 
 	newfile = sock_alloc_file(sock, flags, NULL);
-	if (likely(!IS_ERR(newfile))) {
+	if (!IS_ERR(newfile)) {
 		fd_install(fd, newfile);
 		return fd;
 	}
@@ -424,6 +427,14 @@
 	return PTR_ERR(newfile);
 }
 
+/**
+ *	sock_from_file - Return the &socket bounded to @file.
+ *	@file: file
+ *	@err: pointer to an error code return
+ *
+ *	On failure returns %NULL and assigns -ENOTSOCK to @err.
+ */
+
 struct socket *sock_from_file(struct file *file, int *err)
 {
 	if (file->f_op == &socket_file_ops)
@@ -532,11 +543,11 @@
 };
 
 /**
- *	sock_alloc	-	allocate a socket
+ *	sock_alloc - allocate a socket
  *
  *	Allocate a new inode and socket object. The two are bound together
  *	and initialised. The socket is then returned. If we are out of inodes
- *	NULL is returned.
+ *	NULL is returned. This functions uses GFP_KERNEL internally.
  */
 
 struct socket *sock_alloc(void)
@@ -561,7 +572,7 @@
 EXPORT_SYMBOL(sock_alloc);
 
 /**
- *	sock_release	-	close a socket
+ *	sock_release - close a socket
  *	@sock: socket to close
  *
  *	The socket is released from the protocol stack if it has a release
@@ -577,13 +588,14 @@
 		if (inode)
 			inode_lock(inode);
 		sock->ops->release(sock);
+		sock->sk = NULL;
 		if (inode)
 			inode_unlock(inode);
 		sock->ops = NULL;
 		module_put(owner);
 	}
 
-	if (sock->wq->fasync_list)
+	if (sock->wq.fasync_list)
 		pr_err("%s: fasync list not empty!\n", __func__);
 
 	if (!sock->file) {
@@ -616,13 +628,27 @@
 }
 EXPORT_SYMBOL(__sock_tx_timestamp);
 
+INDIRECT_CALLABLE_DECLARE(int inet_sendmsg(struct socket *, struct msghdr *,
+					   size_t));
+INDIRECT_CALLABLE_DECLARE(int inet6_sendmsg(struct socket *, struct msghdr *,
+					    size_t));
 static inline int sock_sendmsg_nosec(struct socket *sock, struct msghdr *msg)
 {
-	int ret = sock->ops->sendmsg(sock, msg, msg_data_left(msg));
+	int ret = INDIRECT_CALL_INET(sock->ops->sendmsg, inet6_sendmsg,
+				     inet_sendmsg, sock, msg,
+				     msg_data_left(msg));
 	BUG_ON(ret == -EIOCBQUEUED);
 	return ret;
 }
 
+/**
+ *	sock_sendmsg - send a message through @sock
+ *	@sock: socket
+ *	@msg: message to send
+ *
+ *	Sends @msg through @sock, passing through LSM.
+ *	Returns the number of bytes sent, or an error code.
+ */
 int sock_sendmsg(struct socket *sock, struct msghdr *msg)
 {
 	int err = security_socket_sendmsg(sock, msg,
@@ -632,14 +658,39 @@
 }
 EXPORT_SYMBOL(sock_sendmsg);
 
+/**
+ *	kernel_sendmsg - send a message through @sock (kernel-space)
+ *	@sock: socket
+ *	@msg: message header
+ *	@vec: kernel vec
+ *	@num: vec array length
+ *	@size: total message data size
+ *
+ *	Builds the message data with @vec and sends it through @sock.
+ *	Returns the number of bytes sent, or an error code.
+ */
+
 int kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 		   struct kvec *vec, size_t num, size_t size)
 {
-	iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
 	return sock_sendmsg(sock, msg);
 }
 EXPORT_SYMBOL(kernel_sendmsg);
 
+/**
+ *	kernel_sendmsg_locked - send a message through @sock (kernel-space)
+ *	@sk: sock
+ *	@msg: message header
+ *	@vec: output s/g array
+ *	@num: output s/g array length
+ *	@size: total message data size
+ *
+ *	Builds the message data with @vec and sends it through @sock.
+ *	Returns the number of bytes sent, or an error code.
+ *	Caller must hold @sk.
+ */
+
 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
 			  struct kvec *vec, size_t num, size_t size)
 {
@@ -648,7 +699,7 @@
 	if (!sock->ops->sendmsg_locked)
 		return sock_no_sendmsg_locked(sk, msg, size);
 
-	iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, WRITE, vec, num, size);
 
 	return sock->ops->sendmsg_locked(sk, msg, msg_data_left(msg));
 }
@@ -669,7 +720,7 @@
  * before the software timestamp is received, a hardware TX timestamp may be
  * returned only if there is no software TX timestamp. Ignore false software
  * timestamps, which may be made in the __sock_recv_timestamp() call when the
- * option SO_TIMESTAMP(NS) is enabled on the socket, even when the skb has a
+ * option SO_TIMESTAMP_OLD(NS) is enabled on the socket, even when the skb has a
  * hardware timestamp.
  */
 static bool skb_is_swtx_tstamp(const struct sk_buff *skb, int false_tstamp)
@@ -705,7 +756,9 @@
 	struct sk_buff *skb)
 {
 	int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
-	struct scm_timestamping tss;
+	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
+	struct scm_timestamping_internal tss;
+
 	int empty = 1, false_tstamp = 0;
 	struct skb_shared_hwtstamps *shhwtstamps =
 		skb_hwtstamps(skb);
@@ -719,34 +772,54 @@
 
 	if (need_software_tstamp) {
 		if (!sock_flag(sk, SOCK_RCVTSTAMPNS)) {
-			struct timeval tv;
-			skb_get_timestamp(skb, &tv);
-			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
-				 sizeof(tv), &tv);
+			if (new_tstamp) {
+				struct __kernel_sock_timeval tv;
+
+				skb_get_new_timestamp(skb, &tv);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
+					 sizeof(tv), &tv);
+			} else {
+				struct __kernel_old_timeval tv;
+
+				skb_get_timestamp(skb, &tv);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
+					 sizeof(tv), &tv);
+			}
 		} else {
-			struct timespec ts;
-			skb_get_timestampns(skb, &ts);
-			put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
-				 sizeof(ts), &ts);
+			if (new_tstamp) {
+				struct __kernel_timespec ts;
+
+				skb_get_new_timestampns(skb, &ts);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
+					 sizeof(ts), &ts);
+			} else {
+				struct timespec ts;
+
+				skb_get_timestampns(skb, &ts);
+				put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
+					 sizeof(ts), &ts);
+			}
 		}
 	}
 
 	memset(&tss, 0, sizeof(tss));
 	if ((sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) &&
-	    ktime_to_timespec_cond(skb->tstamp, tss.ts + 0))
+	    ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
 		empty = 0;
 	if (shhwtstamps &&
 	    (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
 	    !skb_is_swtx_tstamp(skb, false_tstamp) &&
-	    ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2)) {
+	    ktime_to_timespec64_cond(shhwtstamps->hwtstamp, tss.ts + 2)) {
 		empty = 0;
 		if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
 		    !skb_is_err_queue(skb))
 			put_ts_pktinfo(msg, skb);
 	}
 	if (!empty) {
-		put_cmsg(msg, SOL_SOCKET,
-			 SCM_TIMESTAMPING, sizeof(tss), &tss);
+		if (sock_flag(sk, SOCK_TSTAMP_NEW))
+			put_cmsg_scm_timestamping64(msg, &tss);
+		else
+			put_cmsg_scm_timestamping(msg, &tss);
 
 		if (skb_is_err_queue(skb) && skb->len &&
 		    SKB_EXT_ERR(skb)->opt_stats)
@@ -788,12 +861,27 @@
 }
 EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
 
+INDIRECT_CALLABLE_DECLARE(int inet_recvmsg(struct socket *, struct msghdr *,
+					   size_t, int));
+INDIRECT_CALLABLE_DECLARE(int inet6_recvmsg(struct socket *, struct msghdr *,
+					    size_t, int));
 static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
 				     int flags)
 {
-	return sock->ops->recvmsg(sock, msg, msg_data_left(msg), flags);
+	return INDIRECT_CALL_INET(sock->ops->recvmsg, inet6_recvmsg,
+				  inet_recvmsg, sock, msg, msg_data_left(msg),
+				  flags);
 }
 
+/**
+ *	sock_recvmsg - receive a message from @sock
+ *	@sock: socket
+ *	@msg: message to receive
+ *	@flags: message flags
+ *
+ *	Receives @msg from @sock, passing through LSM. Returns the total number
+ *	of bytes received, or an error.
+ */
 int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
 {
 	int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
@@ -803,27 +891,28 @@
 EXPORT_SYMBOL(sock_recvmsg);
 
 /**
- * kernel_recvmsg - Receive a message from a socket (kernel space)
- * @sock:       The socket to receive the message from
- * @msg:        Received message
- * @vec:        Input s/g array for message data
- * @num:        Size of input s/g array
- * @size:       Number of bytes to read
- * @flags:      Message flags (MSG_DONTWAIT, etc...)
+ *	kernel_recvmsg - Receive a message from a socket (kernel space)
+ *	@sock: The socket to receive the message from
+ *	@msg: Received message
+ *	@vec: Input s/g array for message data
+ *	@num: Size of input s/g array
+ *	@size: Number of bytes to read
+ *	@flags: Message flags (MSG_DONTWAIT, etc...)
  *
- * On return the msg structure contains the scatter/gather array passed in the
- * vec argument. The array is modified so that it consists of the unfilled
- * portion of the original array.
+ *	On return the msg structure contains the scatter/gather array passed in the
+ *	vec argument. The array is modified so that it consists of the unfilled
+ *	portion of the original array.
  *
- * The returned value is the total number of bytes received, or an error.
+ *	The returned value is the total number of bytes received, or an error.
  */
+
 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
 		   struct kvec *vec, size_t num, size_t size, int flags)
 {
 	mm_segment_t oldfs = get_fs();
 	int result;
 
-	iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size);
+	iov_iter_kvec(&msg->msg_iter, READ, vec, num, size);
 	set_fs(KERNEL_DS);
 	result = sock_recvmsg(sock, msg, flags);
 	set_fs(oldfs);
@@ -853,7 +942,7 @@
 	struct socket *sock = file->private_data;
 
 	if (unlikely(!sock->ops->splice_read))
-		return -EINVAL;
+		return generic_file_splice_read(file, ppos, pipe, len, flags);
 
 	return sock->ops->splice_read(sock, ppos, pipe, len, flags);
 }
@@ -941,8 +1030,7 @@
 EXPORT_SYMBOL(dlci_ioctl_set);
 
 static long sock_do_ioctl(struct net *net, struct socket *sock,
-			  unsigned int cmd, unsigned long arg,
-			  unsigned int ifreq_size)
+			  unsigned int cmd, unsigned long arg)
 {
 	int err;
 	void __user *argp = (void __user *)arg;
@@ -968,11 +1056,11 @@
 	} else {
 		struct ifreq ifr;
 		bool need_copyout;
-		if (copy_from_user(&ifr, argp, ifreq_size))
+		if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
 			return -EFAULT;
 		err = dev_ioctl(net, cmd, &ifr, &need_copyout);
 		if (!err && need_copyout)
-			if (copy_to_user(argp, &ifr, ifreq_size))
+			if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
 				return -EFAULT;
 	}
 	return err;
@@ -983,6 +1071,13 @@
  *	what to do with it - that's up to the protocol still.
  */
 
+/**
+ *	get_net_ns - increment the refcount of the network namespace
+ *	@ns: common namespace (net)
+ *
+ *	Returns the net's common namespace.
+ */
+
 struct ns_common *get_net_ns(struct ns_common *ns)
 {
 	return &get_net(container_of(ns, struct net, ns))->ns;
@@ -1070,14 +1165,46 @@
 
 			err = open_related_ns(&net->ns, get_net_ns);
 			break;
+		case SIOCGSTAMP_OLD:
+		case SIOCGSTAMPNS_OLD:
+			if (!sock->ops->gettstamp) {
+				err = -ENOIOCTLCMD;
+				break;
+			}
+			err = sock->ops->gettstamp(sock, argp,
+						   cmd == SIOCGSTAMP_OLD,
+						   !IS_ENABLED(CONFIG_64BIT));
+			break;
+		case SIOCGSTAMP_NEW:
+		case SIOCGSTAMPNS_NEW:
+			if (!sock->ops->gettstamp) {
+				err = -ENOIOCTLCMD;
+				break;
+			}
+			err = sock->ops->gettstamp(sock, argp,
+						   cmd == SIOCGSTAMP_NEW,
+						   false);
+			break;
 		default:
-			err = sock_do_ioctl(net, sock, cmd, arg,
-					    sizeof(struct ifreq));
+			err = sock_do_ioctl(net, sock, cmd, arg);
 			break;
 		}
 	return err;
 }
 
+/**
+ *	sock_create_lite - creates a socket
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *
+ *	Creates a new socket and assigns it to @res, passing through LSM.
+ *	The new socket initialization is not complete, see kernel_accept().
+ *	Returns 0 or an error. On failure @res is set to %NULL.
+ *	This function internally uses GFP_KERNEL.
+ */
+
 int sock_create_lite(int family, int type, int protocol, struct socket **res)
 {
 	int err;
@@ -1157,13 +1284,12 @@
 {
 	struct socket *sock = filp->private_data;
 	struct sock *sk = sock->sk;
-	struct socket_wq *wq;
+	struct socket_wq *wq = &sock->wq;
 
 	if (sk == NULL)
 		return -EINVAL;
 
 	lock_sock(sk);
-	wq = sock->wq;
 	fasync_helper(fd, filp, on, &wq->fasync_list);
 
 	if (!wq->fasync_list)
@@ -1203,6 +1329,21 @@
 }
 EXPORT_SYMBOL(sock_wake_async);
 
+/**
+ *	__sock_create - creates a socket
+ *	@net: net namespace
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *	@kern: boolean for kernel space sockets
+ *
+ *	Creates a new socket and assigns it to @res, passing through LSM.
+ *	Returns 0 or an error. On failure @res is set to %NULL. @kern must
+ *	be set to true if the socket resides in kernel space.
+ *	This function internally uses GFP_KERNEL.
+ */
+
 int __sock_create(struct net *net, int family, int type, int protocol,
 			 struct socket **res, int kern)
 {
@@ -1312,12 +1453,35 @@
 }
 EXPORT_SYMBOL(__sock_create);
 
+/**
+ *	sock_create - creates a socket
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *
+ *	A wrapper around __sock_create().
+ *	Returns 0 or an error. This function internally uses GFP_KERNEL.
+ */
+
 int sock_create(int family, int type, int protocol, struct socket **res)
 {
 	return __sock_create(current->nsproxy->net_ns, family, type, protocol, res, 0);
 }
 EXPORT_SYMBOL(sock_create);
 
+/**
+ *	sock_create_kern - creates a socket (kernel space)
+ *	@net: net namespace
+ *	@family: protocol family (AF_INET, ...)
+ *	@type: communication type (SOCK_STREAM, ...)
+ *	@protocol: protocol (0, ...)
+ *	@res: new socket
+ *
+ *	A wrapper around __sock_create().
+ *	Returns 0 or an error. This function internally uses GFP_KERNEL.
+ */
+
 int sock_create_kern(struct net *net, int family, int type, int protocol, struct socket **res)
 {
 	return __sock_create(net, family, type, protocol, res, 1);
@@ -1475,7 +1639,7 @@
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (sock) {
 		err = move_addr_to_kernel(umyaddr, addrlen, &address);
-		if (err >= 0) {
+		if (!err) {
 			err = security_socket_bind(sock,
 						   (struct sockaddr *)&address,
 						   addrlen);
@@ -1881,6 +2045,8 @@
 static int __sys_setsockopt(int fd, int level, int optname,
 			    char __user *optval, int optlen)
 {
+	mm_segment_t oldfs = get_fs();
+	char *kernel_optval = NULL;
 	int err, fput_needed;
 	struct socket *sock;
 
@@ -1893,6 +2059,22 @@
 		if (err)
 			goto out_put;
 
+		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level,
+						     &optname, optval, &optlen,
+						     &kernel_optval);
+
+		if (err < 0) {
+			goto out_put;
+		} else if (err > 0) {
+			err = 0;
+			goto out_put;
+		}
+
+		if (kernel_optval) {
+			set_fs(KERNEL_DS);
+			optval = (char __user __force *)kernel_optval;
+		}
+
 		if (level == SOL_SOCKET)
 			err =
 			    sock_setsockopt(sock, level, optname, optval,
@@ -1901,6 +2083,11 @@
 			err =
 			    sock->ops->setsockopt(sock, level, optname, optval,
 						  optlen);
+
+		if (kernel_optval) {
+			set_fs(oldfs);
+			kfree(kernel_optval);
+		}
 out_put:
 		fput_light(sock->file, fput_needed);
 	}
@@ -1923,6 +2110,7 @@
 {
 	int err, fput_needed;
 	struct socket *sock;
+	int max_optlen;
 
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (sock != NULL) {
@@ -1930,6 +2118,8 @@
 		if (err)
 			goto out_put;
 
+		max_optlen = BPF_CGROUP_GETSOCKOPT_MAX_OPTLEN(optlen);
+
 		if (level == SOL_SOCKET)
 			err =
 			    sock_getsockopt(sock, level, optname, optval,
@@ -1938,6 +2128,10 @@
 			err =
 			    sock->ops->getsockopt(sock, level, optname, optval,
 						  optlen);
+
+		err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, optname,
+						     optval, optlen,
+						     max_optlen, err);
 out_put:
 		fput_light(sock->file, fput_needed);
 	}
@@ -2032,20 +2226,16 @@
 
 	kmsg->msg_iocb = NULL;
 
-	return import_iovec(save_addr ? READ : WRITE,
+	err = import_iovec(save_addr ? READ : WRITE,
 			    msg.msg_iov, msg.msg_iovlen,
 			    UIO_FASTIOV, iov, &kmsg->msg_iter);
+	return err < 0 ? err : 0;
 }
 
-static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
-			 struct msghdr *msg_sys, unsigned int flags,
-			 struct used_address *used_address,
-			 unsigned int allowed_msghdr_flags)
+static int ____sys_sendmsg(struct socket *sock, struct msghdr *msg_sys,
+			   unsigned int flags, struct used_address *used_address,
+			   unsigned int allowed_msghdr_flags)
 {
-	struct compat_msghdr __user *msg_compat =
-	    (struct compat_msghdr __user *)msg;
-	struct sockaddr_storage address;
-	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
 	unsigned char ctl[sizeof(struct cmsghdr) + 20]
 				__aligned(sizeof(__kernel_size_t));
 	/* 20 is size of ipv6_pktinfo */
@@ -2053,19 +2243,10 @@
 	int ctl_len;
 	ssize_t err;
 
-	msg_sys->msg_name = &address;
-
-	if (MSG_CMSG_COMPAT & flags)
-		err = get_compat_msghdr(msg_sys, msg_compat, NULL, &iov);
-	else
-		err = copy_msghdr_from_user(msg_sys, msg, NULL, &iov);
-	if (err < 0)
-		return err;
-
 	err = -ENOBUFS;
 
 	if (msg_sys->msg_controllen > INT_MAX)
-		goto out_freeiov;
+		goto out;
 	flags |= (msg_sys->msg_flags & allowed_msghdr_flags);
 	ctl_len = msg_sys->msg_controllen;
 	if ((MSG_CMSG_COMPAT & flags) && ctl_len) {
@@ -2073,7 +2254,7 @@
 		    cmsghdr_from_user_compat_to_kern(msg_sys, sock->sk, ctl,
 						     sizeof(ctl));
 		if (err)
-			goto out_freeiov;
+			goto out;
 		ctl_buf = msg_sys->msg_control;
 		ctl_len = msg_sys->msg_controllen;
 	} else if (ctl_len) {
@@ -2082,7 +2263,7 @@
 		if (ctl_len > sizeof(ctl)) {
 			ctl_buf = sock_kmalloc(sock->sk, ctl_len, GFP_KERNEL);
 			if (ctl_buf == NULL)
-				goto out_freeiov;
+				goto out;
 		}
 		err = -EFAULT;
 		/*
@@ -2128,7 +2309,47 @@
 out_freectl:
 	if (ctl_buf != ctl)
 		sock_kfree_s(sock->sk, ctl_buf, ctl_len);
-out_freeiov:
+out:
+	return err;
+}
+
+static int sendmsg_copy_msghdr(struct msghdr *msg,
+			       struct user_msghdr __user *umsg, unsigned flags,
+			       struct iovec **iov)
+{
+	int err;
+
+	if (flags & MSG_CMSG_COMPAT) {
+		struct compat_msghdr __user *msg_compat;
+
+		msg_compat = (struct compat_msghdr __user *) umsg;
+		err = get_compat_msghdr(msg, msg_compat, NULL, iov);
+	} else {
+		err = copy_msghdr_from_user(msg, umsg, NULL, iov);
+	}
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int ___sys_sendmsg(struct socket *sock, struct user_msghdr __user *msg,
+			 struct msghdr *msg_sys, unsigned int flags,
+			 struct used_address *used_address,
+			 unsigned int allowed_msghdr_flags)
+{
+	struct sockaddr_storage address;
+	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+	ssize_t err;
+
+	msg_sys->msg_name = &address;
+
+	err = sendmsg_copy_msghdr(msg_sys, msg, flags, &iov);
+	if (err < 0)
+		return err;
+
+	err = ____sys_sendmsg(sock, msg_sys, flags, used_address,
+				allowed_msghdr_flags);
 	kfree(iov);
 	return err;
 }
@@ -2136,6 +2357,28 @@
 /*
  *	BSD sendmsg interface
  */
+long __sys_sendmsg_sock(struct socket *sock, struct user_msghdr __user *umsg,
+			unsigned int flags)
+{
+	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+	struct sockaddr_storage address;
+	struct msghdr msg = { .msg_name = &address };
+	ssize_t err;
+
+	err = sendmsg_copy_msghdr(&msg, umsg, flags, &iov);
+	if (err)
+		return err;
+	/* disallow ancillary data requests from this path */
+	if (msg.msg_control || msg.msg_controllen) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	err = ____sys_sendmsg(sock, &msg, flags, NULL, 0);
+out:
+	kfree(iov);
+	return err;
+}
 
 long __sys_sendmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
 		   bool forbid_cmsg_compat)
@@ -2240,33 +2483,41 @@
 	return __sys_sendmmsg(fd, mmsg, vlen, flags, true);
 }
 
-static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
-			 struct msghdr *msg_sys, unsigned int flags, int nosec)
+static int recvmsg_copy_msghdr(struct msghdr *msg,
+			       struct user_msghdr __user *umsg, unsigned flags,
+			       struct sockaddr __user **uaddr,
+			       struct iovec **iov)
+{
+	ssize_t err;
+
+	if (MSG_CMSG_COMPAT & flags) {
+		struct compat_msghdr __user *msg_compat;
+
+		msg_compat = (struct compat_msghdr __user *) umsg;
+		err = get_compat_msghdr(msg, msg_compat, uaddr, iov);
+	} else {
+		err = copy_msghdr_from_user(msg, umsg, uaddr, iov);
+	}
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int ____sys_recvmsg(struct socket *sock, struct msghdr *msg_sys,
+			   struct user_msghdr __user *msg,
+			   struct sockaddr __user *uaddr,
+			   unsigned int flags, int nosec)
 {
 	struct compat_msghdr __user *msg_compat =
-	    (struct compat_msghdr __user *)msg;
-	struct iovec iovstack[UIO_FASTIOV];
-	struct iovec *iov = iovstack;
+					(struct compat_msghdr __user *) msg;
+	int __user *uaddr_len = COMPAT_NAMELEN(msg);
+	struct sockaddr_storage addr;
 	unsigned long cmsg_ptr;
 	int len;
 	ssize_t err;
 
-	/* kernel mode address */
-	struct sockaddr_storage addr;
-
-	/* user mode address pointers */
-	struct sockaddr __user *uaddr;
-	int __user *uaddr_len = COMPAT_NAMELEN(msg);
-
 	msg_sys->msg_name = &addr;
-
-	if (MSG_CMSG_COMPAT & flags)
-		err = get_compat_msghdr(msg_sys, msg_compat, &uaddr, &iov);
-	else
-		err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov);
-	if (err < 0)
-		return err;
-
 	cmsg_ptr = (unsigned long)msg_sys->msg_control;
 	msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
 
@@ -2277,7 +2528,7 @@
 		flags |= MSG_DONTWAIT;
 	err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys, flags);
 	if (err < 0)
-		goto out_freeiov;
+		goto out;
 	len = err;
 
 	if (uaddr != NULL) {
@@ -2285,12 +2536,12 @@
 					msg_sys->msg_namelen, uaddr,
 					uaddr_len);
 		if (err < 0)
-			goto out_freeiov;
+			goto out;
 	}
 	err = __put_user((msg_sys->msg_flags & ~MSG_CMSG_COMPAT),
 			 COMPAT_FLAGS(msg));
 	if (err)
-		goto out_freeiov;
+		goto out;
 	if (MSG_CMSG_COMPAT & flags)
 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
 				 &msg_compat->msg_controllen);
@@ -2298,10 +2549,25 @@
 		err = __put_user((unsigned long)msg_sys->msg_control - cmsg_ptr,
 				 &msg->msg_controllen);
 	if (err)
-		goto out_freeiov;
+		goto out;
 	err = len;
+out:
+	return err;
+}
 
-out_freeiov:
+static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
+			 struct msghdr *msg_sys, unsigned int flags, int nosec)
+{
+	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+	/* user mode address pointers */
+	struct sockaddr __user *uaddr;
+	ssize_t err;
+
+	err = recvmsg_copy_msghdr(msg_sys, msg, flags, &uaddr, &iov);
+	if (err < 0)
+		return err;
+
+	err = ____sys_recvmsg(sock, msg_sys, msg, uaddr, flags, nosec);
 	kfree(iov);
 	return err;
 }
@@ -2310,6 +2576,30 @@
  *	BSD recvmsg interface
  */
 
+long __sys_recvmsg_sock(struct socket *sock, struct user_msghdr __user *umsg,
+			unsigned int flags)
+{
+	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
+	struct sockaddr_storage address;
+	struct msghdr msg = { .msg_name = &address };
+	struct sockaddr __user *uaddr;
+	ssize_t err;
+
+	err = recvmsg_copy_msghdr(&msg, umsg, flags, &uaddr, &iov);
+	if (err)
+		return err;
+	/* disallow ancillary data requests from this path */
+	if (msg.msg_control || msg.msg_controllen) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	err = ____sys_recvmsg(sock, &msg, umsg, uaddr, flags, 0);
+out:
+	kfree(iov);
+	return err;
+}
+
 long __sys_recvmsg(int fd, struct user_msghdr __user *msg, unsigned int flags,
 		   bool forbid_cmsg_compat)
 {
@@ -2341,8 +2631,9 @@
  *     Linux recvmmsg interface
  */
 
-int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
-		   unsigned int flags, struct timespec *timeout)
+static int do_recvmmsg(int fd, struct mmsghdr __user *mmsg,
+			  unsigned int vlen, unsigned int flags,
+			  struct timespec64 *timeout)
 {
 	int fput_needed, err, datagrams;
 	struct socket *sock;
@@ -2407,8 +2698,7 @@
 
 		if (timeout) {
 			ktime_get_ts64(&timeout64);
-			*timeout = timespec64_to_timespec(
-					timespec64_sub(end_time, timeout64));
+			*timeout = timespec64_sub(end_time, timeout64);
 			if (timeout->tv_sec < 0) {
 				timeout->tv_sec = timeout->tv_nsec = 0;
 				break;
@@ -2452,26 +2742,32 @@
 	return datagrams;
 }
 
-static int do_sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
-			   unsigned int vlen, unsigned int flags,
-			   struct timespec __user *timeout)
+int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg,
+		   unsigned int vlen, unsigned int flags,
+		   struct __kernel_timespec __user *timeout,
+		   struct old_timespec32 __user *timeout32)
 {
 	int datagrams;
-	struct timespec timeout_sys;
+	struct timespec64 timeout_sys;
 
-	if (flags & MSG_CMSG_COMPAT)
-		return -EINVAL;
-
-	if (!timeout)
-		return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL);
-
-	if (copy_from_user(&timeout_sys, timeout, sizeof(timeout_sys)))
+	if (timeout && get_timespec64(&timeout_sys, timeout))
 		return -EFAULT;
 
-	datagrams = __sys_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
+	if (timeout32 && get_old_timespec32(&timeout_sys, timeout32))
+		return -EFAULT;
 
-	if (datagrams > 0 &&
-	    copy_to_user(timeout, &timeout_sys, sizeof(timeout_sys)))
+	if (!timeout && !timeout32)
+		return do_recvmmsg(fd, mmsg, vlen, flags, NULL);
+
+	datagrams = do_recvmmsg(fd, mmsg, vlen, flags, &timeout_sys);
+
+	if (datagrams <= 0)
+		return datagrams;
+
+	if (timeout && put_timespec64(&timeout_sys, timeout))
+		datagrams = -EFAULT;
+
+	if (timeout32 && put_old_timespec32(&timeout_sys, timeout32))
 		datagrams = -EFAULT;
 
 	return datagrams;
@@ -2479,11 +2775,26 @@
 
 SYSCALL_DEFINE5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg,
 		unsigned int, vlen, unsigned int, flags,
-		struct timespec __user *, timeout)
+		struct __kernel_timespec __user *, timeout)
 {
-	return do_sys_recvmmsg(fd, mmsg, vlen, flags, timeout);
+	if (flags & MSG_CMSG_COMPAT)
+		return -EINVAL;
+
+	return __sys_recvmmsg(fd, mmsg, vlen, flags, timeout, NULL);
 }
 
+#ifdef CONFIG_COMPAT_32BIT_TIME
+SYSCALL_DEFINE5(recvmmsg_time32, int, fd, struct mmsghdr __user *, mmsg,
+		unsigned int, vlen, unsigned int, flags,
+		struct old_timespec32 __user *, timeout)
+{
+	if (flags & MSG_CMSG_COMPAT)
+		return -EINVAL;
+
+	return __sys_recvmmsg(fd, mmsg, vlen, flags, NULL, timeout);
+}
+#endif
+
 #ifdef __ARCH_WANT_SYS_SOCKETCALL
 /* Argument list sizes for sys_socketcall */
 #define AL(x) ((x) * sizeof(unsigned long))
@@ -2602,8 +2913,15 @@
 				    a[2], true);
 		break;
 	case SYS_RECVMMSG:
-		err = do_sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2],
-				      a[3], (struct timespec __user *)a[4]);
+		if (IS_ENABLED(CONFIG_64BIT) || !IS_ENABLED(CONFIG_64BIT_TIME))
+			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
+					     a[2], a[3],
+					     (struct __kernel_timespec __user *)a[4],
+					     NULL);
+		else
+			err = __sys_recvmmsg(a0, (struct mmsghdr __user *)a1,
+					     a[2], a[3], NULL,
+					     (struct old_timespec32 __user *)a[4]);
 		break;
 	case SYS_ACCEPT4:
 		err = __sys_accept4(a0, (struct sockaddr __user *)a1,
@@ -2744,40 +3062,6 @@
 #endif				/* CONFIG_PROC_FS */
 
 #ifdef CONFIG_COMPAT
-static int do_siocgstamp(struct net *net, struct socket *sock,
-			 unsigned int cmd, void __user *up)
-{
-	mm_segment_t old_fs = get_fs();
-	struct timeval ktv;
-	int err;
-
-	set_fs(KERNEL_DS);
-	err = sock_do_ioctl(net, sock, cmd, (unsigned long)&ktv,
-			    sizeof(struct compat_ifreq));
-	set_fs(old_fs);
-	if (!err)
-		err = compat_put_timeval(&ktv, up);
-
-	return err;
-}
-
-static int do_siocgstampns(struct net *net, struct socket *sock,
-			   unsigned int cmd, void __user *up)
-{
-	mm_segment_t old_fs = get_fs();
-	struct timespec kts;
-	int err;
-
-	set_fs(KERNEL_DS);
-	err = sock_do_ioctl(net, sock, cmd, (unsigned long)&kts,
-			    sizeof(struct compat_ifreq));
-	set_fs(old_fs);
-	if (!err)
-		err = compat_put_timespec(&kts, up);
-
-	return err;
-}
-
 static int compat_dev_ifconf(struct net *net, struct compat_ifconf __user *uifc32)
 {
 	struct compat_ifconf ifc32;
@@ -2966,6 +3250,54 @@
 	return dev_ioctl(net, cmd, &ifreq, NULL);
 }
 
+static int compat_ifreq_ioctl(struct net *net, struct socket *sock,
+			      unsigned int cmd,
+			      struct compat_ifreq __user *uifr32)
+{
+	struct ifreq __user *uifr;
+	int err;
+
+	/* Handle the fact that while struct ifreq has the same *layout* on
+	 * 32/64 for everything but ifreq::ifru_ifmap and ifreq::ifru_data,
+	 * which are handled elsewhere, it still has different *size* due to
+	 * ifreq::ifru_ifmap (which is 16 bytes on 32 bit, 24 bytes on 64-bit,
+	 * resulting in struct ifreq being 32 and 40 bytes respectively).
+	 * As a result, if the struct happens to be at the end of a page and
+	 * the next page isn't readable/writable, we get a fault. To prevent
+	 * that, copy back and forth to the full size.
+	 */
+
+	uifr = compat_alloc_user_space(sizeof(*uifr));
+	if (copy_in_user(uifr, uifr32, sizeof(*uifr32)))
+		return -EFAULT;
+
+	err = sock_do_ioctl(net, sock, cmd, (unsigned long)uifr);
+
+	if (!err) {
+		switch (cmd) {
+		case SIOCGIFFLAGS:
+		case SIOCGIFMETRIC:
+		case SIOCGIFMTU:
+		case SIOCGIFMEM:
+		case SIOCGIFHWADDR:
+		case SIOCGIFINDEX:
+		case SIOCGIFADDR:
+		case SIOCGIFBRDADDR:
+		case SIOCGIFDSTADDR:
+		case SIOCGIFNETMASK:
+		case SIOCGIFPFLAGS:
+		case SIOCGIFTXQLEN:
+		case SIOCGMIIPHY:
+		case SIOCGMIIREG:
+		case SIOCGIFNAME:
+			if (copy_in_user(uifr32, uifr, sizeof(*uifr32)))
+				err = -EFAULT;
+			break;
+		}
+	}
+	return err;
+}
+
 static int compat_sioc_ifmap(struct net *net, unsigned int cmd,
 			struct compat_ifreq __user *uifr32)
 {
@@ -3081,8 +3413,7 @@
 	}
 
 	set_fs(KERNEL_DS);
-	ret = sock_do_ioctl(net, sock, cmd, (unsigned long) r,
-			    sizeof(struct compat_ifreq));
+	ret = sock_do_ioctl(net, sock, cmd, (unsigned long) r);
 	set_fs(old_fs);
 
 out:
@@ -3130,10 +3461,13 @@
 	case SIOCADDRT:
 	case SIOCDELRT:
 		return routing_ioctl(net, sock, cmd, argp);
-	case SIOCGSTAMP:
-		return do_siocgstamp(net, sock, cmd, argp);
-	case SIOCGSTAMPNS:
-		return do_siocgstampns(net, sock, cmd, argp);
+	case SIOCGSTAMP_OLD:
+	case SIOCGSTAMPNS_OLD:
+		if (!sock->ops->gettstamp)
+			return -ENOIOCTLCMD;
+		return sock->ops->gettstamp(sock, argp, cmd == SIOCGSTAMP_OLD,
+					    !COMPAT_USE_64BIT_TIME);
+
 	case SIOCBONDSLAVEINFOQUERY:
 	case SIOCBONDINFOQUERY:
 	case SIOCSHWTSTAMP:
@@ -3151,6 +3485,8 @@
 	case SIOCADDDLCI:
 	case SIOCDELDLCI:
 	case SIOCGSKNS:
+	case SIOCGSTAMP_NEW:
+	case SIOCGSTAMPNS_NEW:
 		return sock_ioctl(file, cmd, arg);
 
 	case SIOCGIFFLAGS:
@@ -3182,21 +3518,22 @@
 	case SIOCSIFTXQLEN:
 	case SIOCBRADDIF:
 	case SIOCBRDELIF:
+	case SIOCGIFNAME:
 	case SIOCSIFNAME:
 	case SIOCGMIIPHY:
 	case SIOCGMIIREG:
 	case SIOCSMIIREG:
-	case SIOCSARP:
-	case SIOCGARP:
-	case SIOCDARP:
-	case SIOCATMARK:
 	case SIOCBONDENSLAVE:
 	case SIOCBONDRELEASE:
 	case SIOCBONDSETHWADDR:
 	case SIOCBONDCHANGEACTIVE:
-	case SIOCGIFNAME:
-		return sock_do_ioctl(net, sock, cmd, arg,
-				     sizeof(struct compat_ifreq));
+		return compat_ifreq_ioctl(net, sock, cmd, argp);
+
+	case SIOCSARP:
+	case SIOCGARP:
+	case SIOCDARP:
+	case SIOCATMARK:
+		return sock_do_ioctl(net, sock, cmd, arg);
 	}
 
 	return -ENOIOCTLCMD;
@@ -3227,18 +3564,46 @@
 }
 #endif
 
+/**
+ *	kernel_bind - bind an address to a socket (kernel space)
+ *	@sock: socket
+ *	@addr: address
+ *	@addrlen: length of address
+ *
+ *	Returns 0 or an error.
+ */
+
 int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
 {
 	return sock->ops->bind(sock, addr, addrlen);
 }
 EXPORT_SYMBOL(kernel_bind);
 
+/**
+ *	kernel_listen - move socket to listening state (kernel space)
+ *	@sock: socket
+ *	@backlog: pending connections queue size
+ *
+ *	Returns 0 or an error.
+ */
+
 int kernel_listen(struct socket *sock, int backlog)
 {
 	return sock->ops->listen(sock, backlog);
 }
 EXPORT_SYMBOL(kernel_listen);
 
+/**
+ *	kernel_accept - accept a connection (kernel space)
+ *	@sock: listening socket
+ *	@newsock: new connected socket
+ *	@flags: flags
+ *
+ *	@flags must be SOCK_CLOEXEC, SOCK_NONBLOCK or 0.
+ *	If it fails, @newsock is guaranteed to be %NULL.
+ *	Returns 0 or an error.
+ */
+
 int kernel_accept(struct socket *sock, struct socket **newsock, int flags)
 {
 	struct sock *sk = sock->sk;
@@ -3264,6 +3629,19 @@
 }
 EXPORT_SYMBOL(kernel_accept);
 
+/**
+ *	kernel_connect - connect a socket (kernel space)
+ *	@sock: socket
+ *	@addr: address
+ *	@addrlen: address length
+ *	@flags: flags (O_NONBLOCK, ...)
+ *
+ *	For datagram sockets, @addr is the addres to which datagrams are sent
+ *	by default, and the only address from which datagrams are received.
+ *	For stream sockets, attempts to connect to @addr.
+ *	Returns 0 or an error code.
+ */
+
 int kernel_connect(struct socket *sock, struct sockaddr *addr, int addrlen,
 		   int flags)
 {
@@ -3271,18 +3649,48 @@
 }
 EXPORT_SYMBOL(kernel_connect);
 
+/**
+ *	kernel_getsockname - get the address which the socket is bound (kernel space)
+ *	@sock: socket
+ *	@addr: address holder
+ *
+ * 	Fills the @addr pointer with the address which the socket is bound.
+ *	Returns 0 or an error code.
+ */
+
 int kernel_getsockname(struct socket *sock, struct sockaddr *addr)
 {
 	return sock->ops->getname(sock, addr, 0);
 }
 EXPORT_SYMBOL(kernel_getsockname);
 
+/**
+ *	kernel_peername - get the address which the socket is connected (kernel space)
+ *	@sock: socket
+ *	@addr: address holder
+ *
+ * 	Fills the @addr pointer with the address which the socket is connected.
+ *	Returns 0 or an error code.
+ */
+
 int kernel_getpeername(struct socket *sock, struct sockaddr *addr)
 {
 	return sock->ops->getname(sock, addr, 1);
 }
 EXPORT_SYMBOL(kernel_getpeername);
 
+/**
+ *	kernel_getsockopt - get a socket option (kernel space)
+ *	@sock: socket
+ *	@level: API level (SOL_SOCKET, ...)
+ *	@optname: option tag
+ *	@optval: option value
+ *	@optlen: option length
+ *
+ *	Assigns the option length to @optlen.
+ *	Returns 0 or an error.
+ */
+
 int kernel_getsockopt(struct socket *sock, int level, int optname,
 			char *optval, int *optlen)
 {
@@ -3305,6 +3713,17 @@
 }
 EXPORT_SYMBOL(kernel_getsockopt);
 
+/**
+ *	kernel_setsockopt - set a socket option (kernel space)
+ *	@sock: socket
+ *	@level: API level (SOL_SOCKET, ...)
+ *	@optname: option tag
+ *	@optval: option value
+ *	@optlen: option length
+ *
+ *	Returns 0 or an error.
+ */
+
 int kernel_setsockopt(struct socket *sock, int level, int optname,
 			char *optval, unsigned int optlen)
 {
@@ -3325,6 +3744,17 @@
 }
 EXPORT_SYMBOL(kernel_setsockopt);
 
+/**
+ *	kernel_sendpage - send a &page through a socket (kernel space)
+ *	@sock: socket
+ *	@page: page
+ *	@offset: page offset
+ *	@size: total size in bytes
+ *	@flags: flags (MSG_DONTWAIT, ...)
+ *
+ *	Returns the total amount sent in bytes or an error.
+ */
+
 int kernel_sendpage(struct socket *sock, struct page *page, int offset,
 		    size_t size, int flags)
 {
@@ -3335,6 +3765,18 @@
 }
 EXPORT_SYMBOL(kernel_sendpage);
 
+/**
+ *	kernel_sendpage_locked - send a &page through the locked sock (kernel space)
+ *	@sk: sock
+ *	@page: page
+ *	@offset: page offset
+ *	@size: total size in bytes
+ *	@flags: flags (MSG_DONTWAIT, ...)
+ *
+ *	Returns the total amount sent in bytes or an error.
+ *	Caller must hold @sk.
+ */
+
 int kernel_sendpage_locked(struct sock *sk, struct page *page, int offset,
 			   size_t size, int flags)
 {
@@ -3348,17 +3790,30 @@
 }
 EXPORT_SYMBOL(kernel_sendpage_locked);
 
+/**
+ *	kernel_shutdown - shut down part of a full-duplex connection (kernel space)
+ *	@sock: socket
+ *	@how: connection part
+ *
+ *	Returns 0 or an error.
+ */
+
 int kernel_sock_shutdown(struct socket *sock, enum sock_shutdown_cmd how)
 {
 	return sock->ops->shutdown(sock, how);
 }
 EXPORT_SYMBOL(kernel_sock_shutdown);
 
-/* This routine returns the IP overhead imposed by a socket i.e.
- * the length of the underlying IP header, depending on whether
- * this is an IPv4 or IPv6 socket and the length from IP options turned
- * on at the socket. Assumes that the caller has a lock on the socket.
+/**
+ *	kernel_sock_ip_overhead - returns the IP overhead imposed by a socket
+ *	@sk: socket
+ *
+ *	This routine returns the IP overhead imposed by a socket i.e.
+ *	the length of the underlying IP header, depending on whether
+ *	this is an IPv4 or IPv6 socket and the length from IP options turned
+ *	on at the socket. Assumes that the caller has a lock on the socket.
  */
+
 u32 kernel_sock_ip_overhead(struct sock *sk)
 {
 	struct inet_sock *inet;