diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 8ad93c2..affd665 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2007
  *
  *  Author: Eric Biederman <ebiederm@xmision.com>
- *
- *  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, version 2 of the
- *  License.
  */
 
 #include <linux/module.h>
@@ -88,17 +84,38 @@
 	return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
 }
 
+static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
+	void __user *buffer, size_t *lenp, loff_t *ppos)
+{
+	int ret, semmni;
+	struct ipc_namespace *ns = current->nsproxy->ipc_ns;
+
+	semmni = ns->sem_ctls[3];
+	ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
+
+	if (!ret)
+		ret = sem_check_semmni(current->nsproxy->ipc_ns);
+
+	/*
+	 * Reset the semmni value if an error happens.
+	 */
+	if (ret)
+		ns->sem_ctls[3] = semmni;
+	return ret;
+}
+
 #else
 #define proc_ipc_doulongvec_minmax NULL
 #define proc_ipc_dointvec	   NULL
 #define proc_ipc_dointvec_minmax   NULL
 #define proc_ipc_dointvec_minmax_orphans   NULL
 #define proc_ipc_auto_msgmni	   NULL
+#define proc_ipc_sem_dointvec	   NULL
 #endif
 
-static int zero;
-static int one = 1;
-static int int_max = INT_MAX;
+int ipc_mni = IPCMNI;
+int ipc_mni_shift = IPCMNI_SHIFT;
+int ipc_min_cycle = RADIX_TREE_MAP_SIZE;
 
 static struct ctl_table ipc_kern_table[] = {
 	{
@@ -120,7 +137,9 @@
 		.data		= &init_ipc_ns.shm_ctlmni,
 		.maxlen		= sizeof(init_ipc_ns.shm_ctlmni),
 		.mode		= 0644,
-		.proc_handler	= proc_ipc_dointvec,
+		.proc_handler	= proc_ipc_dointvec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &ipc_mni,
 	},
 	{
 		.procname	= "shm_rmid_forced",
@@ -128,8 +147,8 @@
 		.maxlen		= sizeof(init_ipc_ns.shm_rmid_forced),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax_orphans,
-		.extra1		= &zero,
-		.extra2		= &one,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
 	},
 	{
 		.procname	= "msgmax",
@@ -137,8 +156,8 @@
 		.maxlen		= sizeof(init_ipc_ns.msg_ctlmax),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &int_max,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 	{
 		.procname	= "msgmni",
@@ -146,8 +165,8 @@
 		.maxlen		= sizeof(init_ipc_ns.msg_ctlmni),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &int_max,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= &ipc_mni,
 	},
 	{
 		.procname	= "auto_msgmni",
@@ -155,8 +174,8 @@
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_auto_msgmni,
-		.extra1		= &zero,
-		.extra2		= &one,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
 	},
 	{
 		.procname	=  "msgmnb",
@@ -164,15 +183,15 @@
 		.maxlen		= sizeof(init_ipc_ns.msg_ctlmnb),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &int_max,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 	{
 		.procname	= "sem",
 		.data		= &init_ipc_ns.sem_ctls,
 		.maxlen		= 4*sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_ipc_dointvec,
+		.proc_handler	= proc_ipc_sem_dointvec,
 	},
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	{
@@ -181,8 +200,8 @@
 		.maxlen		= sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &int_max,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 	{
 		.procname	= "msg_next_id",
@@ -190,8 +209,8 @@
 		.maxlen		= sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &int_max,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 	{
 		.procname	= "shm_next_id",
@@ -199,8 +218,8 @@
 		.maxlen		= sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id),
 		.mode		= 0644,
 		.proc_handler	= proc_ipc_dointvec_minmax,
-		.extra1		= &zero,
-		.extra2		= &int_max,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_INT_MAX,
 	},
 #endif
 	{}
@@ -222,3 +241,13 @@
 }
 
 device_initcall(ipc_sysctl_init);
+
+static int __init ipc_mni_extend(char *str)
+{
+	ipc_mni = IPCMNI_EXTEND;
+	ipc_mni_shift = IPCMNI_EXTEND_SHIFT;
+	ipc_min_cycle = IPCMNI_EXTEND_MIN_CYCLE;
+	pr_info("IPCMNI extended to %d.\n", ipc_mni);
+	return 0;
+}
+early_param("ipcmni_extend", ipc_mni_extend);
diff --git a/ipc/mq_sysctl.c b/ipc/mq_sysctl.c
index 68d4e95..7c00f28 100644
--- a/ipc/mq_sysctl.c
+++ b/ipc/mq_sysctl.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Copyright (C) 2007 IBM Corporation
  *
  *  Author: Cedric Le Goater <clg@fr.ibm.com>
- *
- *  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, version 2 of the
- *  License.
  */
 
 #include <linux/nsproxy.h>
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index c0d58f3..3d920ff 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -18,6 +18,7 @@
 #include <linux/pagemap.h>
 #include <linux/file.h>
 #include <linux/mount.h>
+#include <linux/fs_context.h>
 #include <linux/namei.h>
 #include <linux/sysctl.h>
 #include <linux/poll.h>
@@ -42,6 +43,10 @@
 #include <net/sock.h>
 #include "util.h"
 
+struct mqueue_fs_context {
+	struct ipc_namespace	*ipc_ns;
+};
+
 #define MQUEUE_MAGIC	0x19800202
 #define DIRENT_SIZE	20
 #define FILENT_SIZE	80
@@ -71,6 +76,7 @@
 	wait_queue_head_t wait_q;
 
 	struct rb_root msg_tree;
+	struct rb_node *msg_tree_rightmost;
 	struct posix_msg_tree_node *node_cache;
 	struct mq_attr attr;
 
@@ -87,9 +93,11 @@
 	unsigned long qsize; /* size of queue in memory (sum of all msgs) */
 };
 
+static struct file_system_type mqueue_fs_type;
 static const struct inode_operations mqueue_dir_inode_operations;
 static const struct file_operations mqueue_file_operations;
 static const struct super_operations mqueue_super_ops;
+static const struct fs_context_operations mqueue_fs_context_ops;
 static void remove_notification(struct mqueue_inode_info *info);
 
 static struct kmem_cache *mqueue_inode_cachep;
@@ -124,6 +132,7 @@
 {
 	struct rb_node **p, *parent = NULL;
 	struct posix_msg_tree_node *leaf;
+	bool rightmost = true;
 
 	p = &info->msg_tree.rb_node;
 	while (*p) {
@@ -132,9 +141,10 @@
 
 		if (likely(leaf->priority == msg->m_type))
 			goto insert_msg;
-		else if (msg->m_type < leaf->priority)
+		else if (msg->m_type < leaf->priority) {
 			p = &(*p)->rb_left;
-		else
+			rightmost = false;
+		} else
 			p = &(*p)->rb_right;
 	}
 	if (info->node_cache) {
@@ -147,6 +157,10 @@
 		INIT_LIST_HEAD(&leaf->msg_list);
 	}
 	leaf->priority = msg->m_type;
+
+	if (rightmost)
+		info->msg_tree_rightmost = &leaf->rb_node;
+
 	rb_link_node(&leaf->rb_node, parent, p);
 	rb_insert_color(&leaf->rb_node, &info->msg_tree);
 insert_msg:
@@ -156,23 +170,35 @@
 	return 0;
 }
 
+static inline void msg_tree_erase(struct posix_msg_tree_node *leaf,
+				  struct mqueue_inode_info *info)
+{
+	struct rb_node *node = &leaf->rb_node;
+
+	if (info->msg_tree_rightmost == node)
+		info->msg_tree_rightmost = rb_prev(node);
+
+	rb_erase(node, &info->msg_tree);
+	if (info->node_cache) {
+		kfree(leaf);
+	} else {
+		info->node_cache = leaf;
+	}
+}
+
 static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
 {
-	struct rb_node **p, *parent = NULL;
+	struct rb_node *parent = NULL;
 	struct posix_msg_tree_node *leaf;
 	struct msg_msg *msg;
 
 try_again:
-	p = &info->msg_tree.rb_node;
-	while (*p) {
-		parent = *p;
-		/*
-		 * During insert, low priorities go to the left and high to the
-		 * right.  On receive, we want the highest priorities first, so
-		 * walk all the way to the right.
-		 */
-		p = &(*p)->rb_right;
-	}
+	/*
+	 * During insert, low priorities go to the left and high to the
+	 * right.  On receive, we want the highest priorities first, so
+	 * walk all the way to the right.
+	 */
+	parent = info->msg_tree_rightmost;
 	if (!parent) {
 		if (info->attr.mq_curmsgs) {
 			pr_warn_once("Inconsistency in POSIX message queue, "
@@ -187,24 +213,14 @@
 		pr_warn_once("Inconsistency in POSIX message queue, "
 			     "empty leaf node but we haven't implemented "
 			     "lazy leaf delete!\n");
-		rb_erase(&leaf->rb_node, &info->msg_tree);
-		if (info->node_cache) {
-			kfree(leaf);
-		} else {
-			info->node_cache = leaf;
-		}
+		msg_tree_erase(leaf, info);
 		goto try_again;
 	} else {
 		msg = list_first_entry(&leaf->msg_list,
 				       struct msg_msg, m_list);
 		list_del(&msg->m_list);
 		if (list_empty(&leaf->msg_list)) {
-			rb_erase(&leaf->rb_node, &info->msg_tree);
-			if (info->node_cache) {
-				kfree(leaf);
-			} else {
-				info->node_cache = leaf;
-			}
+			msg_tree_erase(leaf, info);
 		}
 	}
 	info->attr.mq_curmsgs--;
@@ -247,6 +263,7 @@
 		info->qsize = 0;
 		info->user = NULL;	/* set when all is ok */
 		info->msg_tree = RB_ROOT;
+		info->msg_tree_rightmost = NULL;
 		info->node_cache = NULL;
 		memset(&info->attr, 0, sizeof(info->attr));
 		info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
@@ -322,7 +339,7 @@
 	return ERR_PTR(ret);
 }
 
-static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
+static int mqueue_fill_super(struct super_block *sb, struct fs_context *fc)
 {
 	struct inode *inode;
 	struct ipc_namespace *ns = sb->s_fs_info;
@@ -343,18 +360,56 @@
 	return 0;
 }
 
-static struct dentry *mqueue_mount(struct file_system_type *fs_type,
-			 int flags, const char *dev_name,
-			 void *data)
+static int mqueue_get_tree(struct fs_context *fc)
 {
-	struct ipc_namespace *ns;
-	if (flags & SB_KERNMOUNT) {
-		ns = data;
-		data = NULL;
-	} else {
-		ns = current->nsproxy->ipc_ns;
-	}
-	return mount_ns(fs_type, flags, data, ns, ns->user_ns, mqueue_fill_super);
+	struct mqueue_fs_context *ctx = fc->fs_private;
+
+	return get_tree_keyed(fc, mqueue_fill_super, ctx->ipc_ns);
+}
+
+static void mqueue_fs_context_free(struct fs_context *fc)
+{
+	struct mqueue_fs_context *ctx = fc->fs_private;
+
+	put_ipc_ns(ctx->ipc_ns);
+	kfree(ctx);
+}
+
+static int mqueue_init_fs_context(struct fs_context *fc)
+{
+	struct mqueue_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(struct mqueue_fs_context), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns);
+	put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns);
+	fc->fs_private = ctx;
+	fc->ops = &mqueue_fs_context_ops;
+	return 0;
+}
+
+static struct vfsmount *mq_create_mount(struct ipc_namespace *ns)
+{
+	struct mqueue_fs_context *ctx;
+	struct fs_context *fc;
+	struct vfsmount *mnt;
+
+	fc = fs_context_for_mount(&mqueue_fs_type, SB_KERNMOUNT);
+	if (IS_ERR(fc))
+		return ERR_CAST(fc);
+
+	ctx = fc->fs_private;
+	put_ipc_ns(ctx->ipc_ns);
+	ctx->ipc_ns = get_ipc_ns(ns);
+	put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns);
+
+	mnt = fc_mount(fc);
+	put_fs_context(fc);
+	return mnt;
 }
 
 static void init_once(void *foo)
@@ -374,24 +429,18 @@
 	return &ei->vfs_inode;
 }
 
-static void mqueue_i_callback(struct rcu_head *head)
+static void mqueue_free_inode(struct inode *inode)
 {
-	struct inode *inode = container_of(head, struct inode, i_rcu);
 	kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
 }
 
-static void mqueue_destroy_inode(struct inode *inode)
-{
-	call_rcu(&inode->i_rcu, mqueue_i_callback);
-}
-
 static void mqueue_evict_inode(struct inode *inode)
 {
 	struct mqueue_inode_info *info;
 	struct user_struct *user;
-	unsigned long mq_bytes, mq_treesize;
 	struct ipc_namespace *ipc_ns;
-	struct msg_msg *msg;
+	struct msg_msg *msg, *nmsg;
+	LIST_HEAD(tmp_msg);
 
 	clear_inode(inode);
 
@@ -402,20 +451,27 @@
 	info = MQUEUE_I(inode);
 	spin_lock(&info->lock);
 	while ((msg = msg_get(info)) != NULL)
-		free_msg(msg);
+		list_add_tail(&msg->m_list, &tmp_msg);
 	kfree(info->node_cache);
 	spin_unlock(&info->lock);
 
-	/* Total amount of bytes accounted for the mqueue */
-	mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
-		min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
-		sizeof(struct posix_msg_tree_node);
-
-	mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
-				  info->attr.mq_msgsize);
+	list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) {
+		list_del(&msg->m_list);
+		free_msg(msg);
+	}
 
 	user = info->user;
 	if (user) {
+		unsigned long mq_bytes, mq_treesize;
+
+		/* Total amount of bytes accounted for the mqueue */
+		mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
+			min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
+			sizeof(struct posix_msg_tree_node);
+
+		mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
+					  info->attr.mq_msgsize);
+
 		spin_lock(&mq_lock);
 		user->mq_bytes -= mq_bytes;
 		/*
@@ -566,8 +622,6 @@
 {
 	struct ext_wait_queue *walk;
 
-	ewp->task = current;
-
 	list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
 		if (walk->task->prio <= current->prio) {
 			list_add_tail(&ewp->list, &walk->list);
@@ -655,7 +709,7 @@
 	 * synchronously. */
 	if (info->notify_owner &&
 	    info->attr.mq_curmsgs == 1) {
-		struct siginfo sig_i;
+		struct kernel_siginfo sig_i;
 		switch (info->notify.sigev_notify) {
 		case SIGEV_NONE:
 			break;
@@ -1186,15 +1240,14 @@
 
 			/* create the notify skb */
 			nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
-			if (!nc) {
-				ret = -ENOMEM;
-				goto out;
-			}
+			if (!nc)
+				return -ENOMEM;
+
 			if (copy_from_user(nc->data,
 					notification->sigev_value.sival_ptr,
 					NOTIFY_COOKIE_LEN)) {
 				ret = -EFAULT;
-				goto out;
+				goto free_skb;
 			}
 
 			/* TODO: add a header? */
@@ -1210,8 +1263,7 @@
 			fdput(f);
 			if (IS_ERR(sock)) {
 				ret = PTR_ERR(sock);
-				sock = NULL;
-				goto out;
+				goto free_skb;
 			}
 
 			timeo = MAX_SCHEDULE_TIMEOUT;
@@ -1220,11 +1272,8 @@
 				sock = NULL;
 				goto retry;
 			}
-			if (ret) {
-				sock = NULL;
-				nc = NULL;
-				goto out;
-			}
+			if (ret)
+				return ret;
 		}
 	}
 
@@ -1279,7 +1328,8 @@
 out:
 	if (sock)
 		netlink_detachskb(sock, nc);
-	else if (nc)
+	else
+free_skb:
 		dev_kfree_skb(nc);
 
 	return ret;
@@ -1461,20 +1511,20 @@
 #endif
 
 #ifdef CONFIG_COMPAT_32BIT_TIME
-static int compat_prepare_timeout(const struct compat_timespec __user *p,
+static int compat_prepare_timeout(const struct old_timespec32 __user *p,
 				   struct timespec64 *ts)
 {
-	if (compat_get_timespec64(ts, p))
+	if (get_old_timespec32(ts, p))
 		return -EFAULT;
 	if (!timespec64_valid(ts))
 		return -EINVAL;
 	return 0;
 }
 
-COMPAT_SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes,
-		       const char __user *, u_msg_ptr,
-		       compat_size_t, msg_len, unsigned int, msg_prio,
-		       const struct compat_timespec __user *, u_abs_timeout)
+SYSCALL_DEFINE5(mq_timedsend_time32, mqd_t, mqdes,
+		const char __user *, u_msg_ptr,
+		unsigned int, msg_len, unsigned int, msg_prio,
+		const struct old_timespec32 __user *, u_abs_timeout)
 {
 	struct timespec64 ts, *p = NULL;
 	if (u_abs_timeout) {
@@ -1486,10 +1536,10 @@
 	return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
 }
 
-COMPAT_SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes,
-		       char __user *, u_msg_ptr,
-		       compat_size_t, msg_len, unsigned int __user *, u_msg_prio,
-		       const struct compat_timespec __user *, u_abs_timeout)
+SYSCALL_DEFINE5(mq_timedreceive_time32, mqd_t, mqdes,
+		char __user *, u_msg_ptr,
+		unsigned int, msg_len, unsigned int __user *, u_msg_prio,
+		const struct old_timespec32 __user *, u_abs_timeout)
 {
 	struct timespec64 ts, *p = NULL;
 	if (u_abs_timeout) {
@@ -1517,20 +1567,27 @@
 
 static const struct super_operations mqueue_super_ops = {
 	.alloc_inode = mqueue_alloc_inode,
-	.destroy_inode = mqueue_destroy_inode,
+	.free_inode = mqueue_free_inode,
 	.evict_inode = mqueue_evict_inode,
 	.statfs = simple_statfs,
 };
 
+static const struct fs_context_operations mqueue_fs_context_ops = {
+	.free		= mqueue_fs_context_free,
+	.get_tree	= mqueue_get_tree,
+};
+
 static struct file_system_type mqueue_fs_type = {
-	.name = "mqueue",
-	.mount = mqueue_mount,
-	.kill_sb = kill_litter_super,
-	.fs_flags = FS_USERNS_MOUNT,
+	.name			= "mqueue",
+	.init_fs_context	= mqueue_init_fs_context,
+	.kill_sb		= kill_litter_super,
+	.fs_flags		= FS_USERNS_MOUNT,
 };
 
 int mq_init_ns(struct ipc_namespace *ns)
 {
+	struct vfsmount *m;
+
 	ns->mq_queues_count  = 0;
 	ns->mq_queues_max    = DFLT_QUEUESMAX;
 	ns->mq_msg_max       = DFLT_MSGMAX;
@@ -1538,12 +1595,10 @@
 	ns->mq_msg_default   = DFLT_MSG;
 	ns->mq_msgsize_default  = DFLT_MSGSIZE;
 
-	ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
-	if (IS_ERR(ns->mq_mnt)) {
-		int err = PTR_ERR(ns->mq_mnt);
-		ns->mq_mnt = NULL;
-		return err;
-	}
+	m = mq_create_mount(ns);
+	if (IS_ERR(m))
+		return PTR_ERR(m);
+	ns->mq_mnt = m;
 	return 0;
 }
 
diff --git a/ipc/msg.c b/ipc/msg.c
index 883642c..8dec945 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -567,9 +567,8 @@
 	return err;
 }
 
-long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
+static long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf, int version)
 {
-	int version;
 	struct ipc_namespace *ns;
 	struct msqid64_ds msqid64;
 	int err;
@@ -577,7 +576,6 @@
 	if (msqid < 0 || cmd < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -613,18 +611,32 @@
 
 SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
 {
-	return ksys_msgctl(msqid, cmd, buf);
+	return ksys_msgctl(msqid, cmd, buf, IPC_64);
 }
 
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_msgctl(msqid, cmd, buf, version);
+}
+
+SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
+{
+	return ksys_old_msgctl(msqid, cmd, buf);
+}
+#endif
+
 #ifdef CONFIG_COMPAT
 
 struct compat_msqid_ds {
 	struct compat_ipc_perm msg_perm;
 	compat_uptr_t msg_first;
 	compat_uptr_t msg_last;
-	compat_time_t msg_stime;
-	compat_time_t msg_rtime;
-	compat_time_t msg_ctime;
+	old_time32_t msg_stime;
+	old_time32_t msg_rtime;
+	old_time32_t msg_ctime;
 	compat_ulong_t msg_lcbytes;
 	compat_ulong_t msg_lqbytes;
 	unsigned short msg_cbytes;
@@ -689,12 +701,11 @@
 	}
 }
 
-long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr)
+static long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr, int version)
 {
 	struct ipc_namespace *ns;
 	int err;
 	struct msqid64_ds msqid64;
-	int version = compat_ipc_parse_version(&cmd);
 
 	ns = current->nsproxy->ipc_ns;
 
@@ -734,8 +745,22 @@
 
 COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
 {
-	return compat_ksys_msgctl(msqid, cmd, uptr);
+	return compat_ksys_msgctl(msqid, cmd, uptr, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_msgctl(msqid, cmd, uptr, version);
+}
+
+COMPAT_SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, void __user *, uptr)
+{
+	return compat_ksys_old_msgctl(msqid, cmd, uptr);
+}
+#endif
 #endif
 
 static int testmsg(struct msg_msg *msg, long type, int mode)
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index 8459802..3149b4a 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * linux/ipc/msgutil.c
  * Copyright (C) 1999, 2004 Manfred Spraul
- *
- * This file is released under GNU General Public Licence version 2 or
- * (at your option) any later version.
- *
- * See the file COPYING for more details.
  */
 
 #include <linux/spinlock.h>
@@ -18,6 +14,7 @@
 #include <linux/utsname.h>
 #include <linux/proc_ns.h>
 #include <linux/uaccess.h>
+#include <linux/sched.h>
 
 #include "util.h"
 
@@ -64,6 +61,9 @@
 	pseg = &msg->next;
 	while (len > 0) {
 		struct msg_msgseg *seg;
+
+		cond_resched();
+
 		alen = min(len, DATALEN_SEG);
 		seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT);
 		if (seg == NULL)
@@ -176,6 +176,8 @@
 	kfree(msg);
 	while (seg != NULL) {
 		struct msg_msgseg *tmp = seg->next;
+
+		cond_resched();
 		kfree(seg);
 		seg = tmp;
 	}
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 2160779..b3ca147 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -42,7 +42,7 @@
 		goto fail;
 
 	err = -ENOMEM;
-	ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
+	ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
 	if (ns == NULL)
 		goto fail_dec;
 
diff --git a/ipc/sem.c b/ipc/sem.c
index 26f8e37..ec97a70 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -488,18 +488,14 @@
 static struct sem_array *sem_alloc(size_t nsems)
 {
 	struct sem_array *sma;
-	size_t size;
 
 	if (nsems > (INT_MAX - sizeof(*sma)) / sizeof(sma->sems[0]))
 		return NULL;
 
-	size = sizeof(*sma) + nsems * sizeof(sma->sems[0]);
-	sma = kvmalloc(size, GFP_KERNEL);
+	sma = kvzalloc(struct_size(sma, sems, nsems), GFP_KERNEL);
 	if (unlikely(!sma))
 		return NULL;
 
-	memset(sma, 0, size);
-
 	return sma;
 }
 
@@ -1634,9 +1630,8 @@
 	return err;
 }
 
-long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg)
+static long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg, int version)
 {
-	int version;
 	struct ipc_namespace *ns;
 	void __user *p = (void __user *)arg;
 	struct semid64_ds semid64;
@@ -1645,7 +1640,6 @@
 	if (semid < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -1682,6 +1676,7 @@
 	case IPC_SET:
 		if (copy_semid_from_user(&semid64, p, version))
 			return -EFAULT;
+		/* fall through */
 	case IPC_RMID:
 		return semctl_down(ns, semid, cmd, &semid64);
 	default:
@@ -1691,15 +1686,29 @@
 
 SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
 {
-	return ksys_semctl(semid, semnum, cmd, arg);
+	return ksys_semctl(semid, semnum, cmd, arg, IPC_64);
 }
 
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_semctl(int semid, int semnum, int cmd, unsigned long arg)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_semctl(semid, semnum, cmd, arg, version);
+}
+
+SYSCALL_DEFINE4(old_semctl, int, semid, int, semnum, int, cmd, unsigned long, arg)
+{
+	return ksys_old_semctl(semid, semnum, cmd, arg);
+}
+#endif
+
 #ifdef CONFIG_COMPAT
 
 struct compat_semid_ds {
 	struct compat_ipc_perm sem_perm;
-	compat_time_t sem_otime;
-	compat_time_t sem_ctime;
+	old_time32_t sem_otime;
+	old_time32_t sem_ctime;
 	compat_uptr_t sem_base;
 	compat_uptr_t sem_pending;
 	compat_uptr_t sem_pending_last;
@@ -1744,12 +1753,11 @@
 	}
 }
 
-long compat_ksys_semctl(int semid, int semnum, int cmd, int arg)
+static long compat_ksys_semctl(int semid, int semnum, int cmd, int arg, int version)
 {
 	void __user *p = compat_ptr(arg);
 	struct ipc_namespace *ns;
 	struct semid64_ds semid64;
-	int version = compat_ipc_parse_version(&cmd);
 	int err;
 
 	ns = current->nsproxy->ipc_ns;
@@ -1792,8 +1800,22 @@
 
 COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg)
 {
-	return compat_ksys_semctl(semid, semnum, cmd, arg);
+	return compat_ksys_semctl(semid, semnum, cmd, arg, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_semctl(semid, semnum, cmd, arg, version);
+}
+
+COMPAT_SYSCALL_DEFINE4(old_semctl, int, semid, int, semnum, int, cmd, int, arg)
+{
+	return compat_ksys_old_semctl(semid, semnum, cmd, arg);
+}
+#endif
 #endif
 
 /* If the task doesn't already have a undo_list, then allocate one
@@ -1830,7 +1852,8 @@
 {
 	struct sem_undo *un;
 
-	list_for_each_entry_rcu(un, &ulp->list_proc, list_proc) {
+	list_for_each_entry_rcu(un, &ulp->list_proc, list_proc,
+				spin_is_locked(&ulp->lock)) {
 		if (un->semid == semid)
 			return un;
 	}
@@ -2214,20 +2237,20 @@
 #ifdef CONFIG_COMPAT_32BIT_TIME
 long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
 			    unsigned int nsops,
-			    const struct compat_timespec __user *timeout)
+			    const struct old_timespec32 __user *timeout)
 {
 	if (timeout) {
 		struct timespec64 ts;
-		if (compat_get_timespec64(&ts, timeout))
+		if (get_old_timespec32(&ts, timeout))
 			return -EFAULT;
 		return do_semtimedop(semid, tsems, nsops, &ts);
 	}
 	return do_semtimedop(semid, tsems, nsops, NULL);
 }
 
-COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems,
+SYSCALL_DEFINE4(semtimedop_time32, int, semid, struct sembuf __user *, tsems,
 		       unsigned int, nsops,
-		       const struct compat_timespec __user *, timeout)
+		       const struct old_timespec32 __user *, timeout)
 {
 	return compat_ksys_semtimedop(semid, tsems, nsops, timeout);
 }
diff --git a/ipc/shm.c b/ipc/shm.c
index 1c65fb3..ce1ca9f 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1137,16 +1137,15 @@
 	return err;
 }
 
-long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
+static long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf, int version)
 {
-	int err, version;
+	int err;
 	struct ipc_namespace *ns;
 	struct shmid64_ds sem64;
 
 	if (cmd < 0 || shmid < 0)
 		return -EINVAL;
 
-	version = ipc_parse_version(&cmd);
 	ns = current->nsproxy->ipc_ns;
 
 	switch (cmd) {
@@ -1194,17 +1193,31 @@
 
 SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 {
-	return ksys_shmctl(shmid, cmd, buf);
+	return ksys_shmctl(shmid, cmd, buf, IPC_64);
 }
 
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
+long ksys_old_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
+{
+	int version = ipc_parse_version(&cmd);
+
+	return ksys_shmctl(shmid, cmd, buf, version);
+}
+
+SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
+{
+	return ksys_old_shmctl(shmid, cmd, buf);
+}
+#endif
+
 #ifdef CONFIG_COMPAT
 
 struct compat_shmid_ds {
 	struct compat_ipc_perm shm_perm;
 	int shm_segsz;
-	compat_time_t shm_atime;
-	compat_time_t shm_dtime;
-	compat_time_t shm_ctime;
+	old_time32_t shm_atime;
+	old_time32_t shm_dtime;
+	old_time32_t shm_ctime;
 	compat_ipc_pid_t shm_cpid;
 	compat_ipc_pid_t shm_lpid;
 	unsigned short shm_nattch;
@@ -1319,11 +1332,10 @@
 	}
 }
 
-long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr)
+long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr, int version)
 {
 	struct ipc_namespace *ns;
 	struct shmid64_ds sem64;
-	int version = compat_ipc_parse_version(&cmd);
 	int err;
 
 	ns = current->nsproxy->ipc_ns;
@@ -1378,8 +1390,22 @@
 
 COMPAT_SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, void __user *, uptr)
 {
-	return compat_ksys_shmctl(shmid, cmd, uptr);
+	return compat_ksys_shmctl(shmid, cmd, uptr, IPC_64);
 }
+
+#ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
+long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr)
+{
+	int version = compat_ipc_parse_version(&cmd);
+
+	return compat_ksys_shmctl(shmid, cmd, uptr, version);
+}
+
+COMPAT_SYSCALL_DEFINE3(old_shmctl, int, shmid, int, cmd, void __user *, uptr)
+{
+	return compat_ksys_old_shmctl(shmid, cmd, uptr);
+}
+#endif
 #endif
 
 /*
diff --git a/ipc/syscall.c b/ipc/syscall.c
index 65d405f..581bdff 100644
--- a/ipc/syscall.c
+++ b/ipc/syscall.c
@@ -17,8 +17,8 @@
 #include <linux/shm.h>
 #include <linux/uaccess.h>
 
-SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
-		unsigned long, third, void __user *, ptr, long, fifth)
+int ksys_ipc(unsigned int call, int first, unsigned long second,
+	unsigned long third, void __user * ptr, long fifth)
 {
 	int version, ret;
 
@@ -35,7 +35,7 @@
 			        (const struct __kernel_timespec __user *)fifth);
 		else if (IS_ENABLED(CONFIG_COMPAT_32BIT_TIME))
 			return compat_ksys_semtimedop(first, ptr, second,
-			        (const struct compat_timespec __user *)fifth);
+			        (const struct old_timespec32 __user *)fifth);
 		else
 			return -ENOSYS;
 
@@ -47,7 +47,7 @@
 			return -EINVAL;
 		if (get_user(arg, (unsigned long __user *) ptr))
 			return -EFAULT;
-		return ksys_semctl(first, second, third, arg);
+		return ksys_old_semctl(first, second, third, arg);
 	}
 
 	case MSGSND:
@@ -75,7 +75,7 @@
 	case MSGGET:
 		return ksys_msgget((key_t) first, second);
 	case MSGCTL:
-		return ksys_msgctl(first, second,
+		return ksys_old_msgctl(first, second,
 				   (struct msqid_ds __user *)ptr);
 
 	case SHMAT:
@@ -100,12 +100,18 @@
 	case SHMGET:
 		return ksys_shmget(first, second, third);
 	case SHMCTL:
-		return ksys_shmctl(first, second,
+		return ksys_old_shmctl(first, second,
 				   (struct shmid_ds __user *) ptr);
 	default:
 		return -ENOSYS;
 	}
 }
+
+SYSCALL_DEFINE6(ipc, unsigned int, call, int, first, unsigned long, second,
+		unsigned long, third, void __user *, ptr, long, fifth)
+{
+	return ksys_ipc(call, first, second, third, ptr, fifth);
+}
 #endif
 
 #ifdef CONFIG_COMPAT
@@ -121,8 +127,8 @@
 };
 
 #ifdef CONFIG_ARCH_WANT_OLD_COMPAT_IPC
-COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
-	u32, third, compat_uptr_t, ptr, u32, fifth)
+int compat_ksys_ipc(u32 call, int first, int second,
+	u32 third, compat_uptr_t ptr, u32 fifth)
 {
 	int version;
 	u32 pad;
@@ -146,7 +152,7 @@
 			return -EINVAL;
 		if (get_user(pad, (u32 __user *) compat_ptr(ptr)))
 			return -EFAULT;
-		return compat_ksys_semctl(first, second, third, pad);
+		return compat_ksys_old_semctl(first, second, third, pad);
 
 	case MSGSND:
 		return compat_ksys_msgsnd(first, ptr, second, third);
@@ -171,7 +177,7 @@
 	case MSGGET:
 		return ksys_msgget(first, second);
 	case MSGCTL:
-		return compat_ksys_msgctl(first, second, compat_ptr(ptr));
+		return compat_ksys_old_msgctl(first, second, compat_ptr(ptr));
 
 	case SHMAT: {
 		int err;
@@ -190,10 +196,16 @@
 	case SHMGET:
 		return ksys_shmget(first, (unsigned int)second, third);
 	case SHMCTL:
-		return compat_ksys_shmctl(first, second, compat_ptr(ptr));
+		return compat_ksys_old_shmctl(first, second, compat_ptr(ptr));
 	}
 
 	return -ENOSYS;
 }
+
+COMPAT_SYSCALL_DEFINE6(ipc, u32, call, int, first, int, second,
+	u32, third, compat_uptr_t, ptr, u32, fifth)
+{
+	return compat_ksys_ipc(call, first, second, third, ptr, fifth);
+}
 #endif
 #endif
diff --git a/ipc/util.c b/ipc/util.c
index 0af0575..d126d15 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -101,7 +101,6 @@
 	.head_offset		= offsetof(struct kern_ipc_perm, khtnode),
 	.key_offset		= offsetof(struct kern_ipc_perm, key),
 	.key_len		= FIELD_SIZEOF(struct kern_ipc_perm, key),
-	.locks_mul		= 1,
 	.automatic_shrinking	= true,
 };
 
@@ -110,7 +109,7 @@
  * @ids: ipc identifier set
  *
  * Set up the sequence range to use for the ipc identifier range (limited
- * below IPCMNI) then initialise the keys hashtable and ids idr.
+ * below ipc_mni) then initialise the keys hashtable and ids idr.
  */
 void ipc_init_ids(struct ipc_ids *ids)
 {
@@ -120,6 +119,7 @@
 	rhashtable_init(&ids->key_ht, &ipc_kht_params);
 	idr_init(&ids->ipcs_idr);
 	ids->max_idx = -1;
+	ids->last_idx = -1;
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	ids->next_id = -1;
 #endif
@@ -193,6 +193,10 @@
  *
  * The caller must own kern_ipc_perm.lock.of the new object.
  * On error, the function returns a (negative) error code.
+ *
+ * To conserve sequence number space, especially with extended ipc_mni,
+ * the sequence number is incremented only when the returned ID is less than
+ * the last one.
  */
 static inline int ipc_idr_alloc(struct ipc_ids *ids, struct kern_ipc_perm *new)
 {
@@ -216,17 +220,42 @@
 	 */
 
 	if (next_id < 0) { /* !CHECKPOINT_RESTORE or next_id is unset */
-		new->seq = ids->seq++;
-		if (ids->seq > IPCID_SEQ_MAX)
-			ids->seq = 0;
-		idx = idr_alloc(&ids->ipcs_idr, new, 0, 0, GFP_NOWAIT);
+		int max_idx;
+
+		max_idx = max(ids->in_use*3/2, ipc_min_cycle);
+		max_idx = min(max_idx, ipc_mni);
+
+		/* allocate the idx, with a NULL struct kern_ipc_perm */
+		idx = idr_alloc_cyclic(&ids->ipcs_idr, NULL, 0, max_idx,
+					GFP_NOWAIT);
+
+		if (idx >= 0) {
+			/*
+			 * idx got allocated successfully.
+			 * Now calculate the sequence number and set the
+			 * pointer for real.
+			 */
+			if (idx <= ids->last_idx) {
+				ids->seq++;
+				if (ids->seq >= ipcid_seq_max())
+					ids->seq = 0;
+			}
+			ids->last_idx = idx;
+
+			new->seq = ids->seq;
+			/* no need for smp_wmb(), this is done
+			 * inside idr_replace, as part of
+			 * rcu_assign_pointer
+			 */
+			idr_replace(&ids->ipcs_idr, new, idx);
+		}
 	} else {
 		new->seq = ipcid_to_seqx(next_id);
 		idx = idr_alloc(&ids->ipcs_idr, new, ipcid_to_idx(next_id),
 				0, GFP_NOWAIT);
 	}
 	if (idx >= 0)
-		new->id = SEQ_MULTIPLIER * new->seq + idx;
+		new->id = (new->seq << ipcmni_seq_shift()) + idx;
 	return idx;
 }
 
@@ -254,8 +283,8 @@
 	/* 1) Initialize the refcount so that ipc_rcu_putref works */
 	refcount_set(&new->refcount, 1);
 
-	if (limit > IPCMNI)
-		limit = IPCMNI;
+	if (limit > ipc_mni)
+		limit = ipc_mni;
 
 	if (ids->in_use >= limit)
 		return -ENOSPC;
@@ -738,7 +767,7 @@
 	if (total >= ids->in_use)
 		return NULL;
 
-	for (; pos < IPCMNI; pos++) {
+	for (; pos < ipc_mni; pos++) {
 		ipc = idr_find(&ids->ipcs_idr, pos);
 		if (ipc != NULL) {
 			*new_pos = pos + 1;
diff --git a/ipc/util.h b/ipc/util.h
index 0a159f6..5766c61 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -15,8 +15,37 @@
 #include <linux/err.h>
 #include <linux/ipc_namespace.h>
 
-#define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
-#define SEQ_MULTIPLIER	(IPCMNI)
+/*
+ * The IPC ID contains 2 separate numbers - index and sequence number.
+ * By default,
+ *   bits  0-14: index (32k, 15 bits)
+ *   bits 15-30: sequence number (64k, 16 bits)
+ *
+ * When IPCMNI extension mode is turned on, the composition changes:
+ *   bits  0-23: index (16M, 24 bits)
+ *   bits 24-30: sequence number (128, 7 bits)
+ */
+#define IPCMNI_SHIFT		15
+#define IPCMNI_EXTEND_SHIFT	24
+#define IPCMNI_EXTEND_MIN_CYCLE	(RADIX_TREE_MAP_SIZE * RADIX_TREE_MAP_SIZE)
+#define IPCMNI			(1 << IPCMNI_SHIFT)
+#define IPCMNI_EXTEND		(1 << IPCMNI_EXTEND_SHIFT)
+
+#ifdef CONFIG_SYSVIPC_SYSCTL
+extern int ipc_mni;
+extern int ipc_mni_shift;
+extern int ipc_min_cycle;
+
+#define ipcmni_seq_shift()	ipc_mni_shift
+#define IPCMNI_IDX_MASK		((1 << ipc_mni_shift) - 1)
+
+#else /* CONFIG_SYSVIPC_SYSCTL */
+
+#define ipc_mni			IPCMNI
+#define ipc_min_cycle		((int)RADIX_TREE_MAP_SIZE)
+#define ipcmni_seq_shift()	IPCMNI_SHIFT
+#define IPCMNI_IDX_MASK		((1 << IPCMNI_SHIFT) - 1)
+#endif /* CONFIG_SYSVIPC_SYSCTL */
 
 void sem_init(void);
 void msg_init(void);
@@ -96,9 +125,9 @@
 #define IPC_MSG_IDS	1
 #define IPC_SHM_IDS	2
 
-#define ipcid_to_idx(id) ((id) % SEQ_MULTIPLIER)
-#define ipcid_to_seqx(id) ((id) / SEQ_MULTIPLIER)
-#define IPCID_SEQ_MAX min_t(int, INT_MAX/SEQ_MULTIPLIER, USHRT_MAX)
+#define ipcid_to_idx(id)  ((id) & IPCMNI_IDX_MASK)
+#define ipcid_to_seqx(id) ((id) >> ipcmni_seq_shift())
+#define ipcid_seq_max()	  (INT_MAX >> ipcmni_seq_shift())
 
 /* must be called with ids->rwsem acquired for writing */
 int ipc_addid(struct ipc_ids *, struct kern_ipc_perm *, int);
@@ -123,8 +152,8 @@
 	if (ids->in_use == 0)
 		return -1;
 
-	if (ids->in_use == IPCMNI)
-		return IPCMNI - 1;
+	if (ids->in_use == ipc_mni)
+		return ipc_mni - 1;
 
 	return ids->max_idx;
 }
@@ -160,10 +189,7 @@
 	}
 }
 
-#ifndef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
-/* On IA-64, we always use the "64-bit version" of the IPC structures.  */
-# define ipc_parse_version(cmd)	IPC_64
-#else
+#ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
 int ipc_parse_version(int *cmd);
 #endif
 
@@ -217,6 +243,15 @@
 void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
 		void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
 
+static inline int sem_check_semmni(struct ipc_namespace *ns) {
+	/*
+	 * Check semmni range [0, ipc_mni]
+	 * semmni is the last element of sem_ctls[4] array
+	 */
+	return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > ipc_mni))
+		? -ERANGE : 0;
+}
+
 #ifdef CONFIG_COMPAT
 #include <linux/compat.h>
 struct compat_ipc_perm {
@@ -237,44 +272,19 @@
 
 static inline int compat_ipc_parse_version(int *cmd)
 {
-#ifdef	CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
 	int version = *cmd & IPC_64;
 	*cmd &= ~IPC_64;
 	return version;
-#else
-	return IPC_64;
-#endif
 }
-#endif
 
-/* for __ARCH_WANT_SYS_IPC */
-long ksys_semtimedop(int semid, struct sembuf __user *tsops,
-		     unsigned int nsops,
-		     const struct __kernel_timespec __user *timeout);
-long ksys_semget(key_t key, int nsems, int semflg);
-long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg);
-long ksys_msgget(key_t key, int msgflg);
-long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf);
-long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
-		 long msgtyp, int msgflg);
-long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
-		 int msgflg);
-long ksys_shmget(key_t key, size_t size, int shmflg);
-long ksys_shmdt(char __user *shmaddr);
-long ksys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf);
-
-/* for CONFIG_ARCH_WANT_OLD_COMPAT_IPC */
-long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems,
-			    unsigned int nsops,
-			    const struct compat_timespec __user *timeout);
-#ifdef CONFIG_COMPAT
-long compat_ksys_semctl(int semid, int semnum, int cmd, int arg);
-long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr);
+long compat_ksys_old_semctl(int semid, int semnum, int cmd, int arg);
+long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr);
 long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
 			compat_long_t msgtyp, int msgflg);
 long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
 		       compat_ssize_t msgsz, int msgflg);
-long compat_ksys_shmctl(int shmid, int cmd, void __user *uptr);
-#endif /* CONFIG_COMPAT */
+long compat_ksys_old_shmctl(int shmid, int cmd, void __user *uptr);
+
+#endif
 
 #endif