Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
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;
 }