Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index fc5306a..dbe43a5 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -24,7 +24,6 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/mount.h>
-#include <linux/magic.h>
 
 #include <linux/uaccess.h>
 
@@ -59,7 +58,6 @@
 static struct inode *proc_alloc_inode(struct super_block *sb)
 {
 	struct proc_inode *ei;
-	struct inode *inode;
 
 	ei = kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
 	if (!ei)
@@ -71,21 +69,14 @@
 	ei->sysctl = NULL;
 	ei->sysctl_entry = NULL;
 	ei->ns_ops = NULL;
-	inode = &ei->vfs_inode;
-	return inode;
+	return &ei->vfs_inode;
 }
 
-static void proc_i_callback(struct rcu_head *head)
+static void proc_free_inode(struct inode *inode)
 {
-	struct inode *inode = container_of(head, struct inode, i_rcu);
 	kmem_cache_free(proc_inode_cachep, PROC_I(inode));
 }
 
-static void proc_destroy_inode(struct inode *inode)
-{
-	call_rcu(&inode->i_rcu, proc_i_callback);
-}
-
 static void init_once(void *foo)
 {
 	struct proc_inode *ei = (struct proc_inode *) foo;
@@ -124,13 +115,12 @@
 	return 0;
 }
 
-static const struct super_operations proc_sops = {
+const struct super_operations proc_sops = {
 	.alloc_inode	= proc_alloc_inode,
-	.destroy_inode	= proc_destroy_inode,
+	.free_inode	= proc_free_inode,
 	.drop_inode	= generic_delete_inode,
 	.evict_inode	= proc_evict_inode,
 	.statfs		= simple_statfs,
-	.remount_fs	= proc_remount,
 	.show_options	= proc_show_options,
 };
 
@@ -210,7 +200,8 @@
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	loff_t rv = -EINVAL;
 	if (use_pde(pde)) {
-		loff_t (*llseek)(struct file *, loff_t, int);
+		typeof_member(struct file_operations, llseek) llseek;
+
 		llseek = pde->proc_fops->llseek;
 		if (!llseek)
 			llseek = default_llseek;
@@ -222,10 +213,11 @@
 
 static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 {
-	ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	ssize_t rv = -EIO;
 	if (use_pde(pde)) {
+		typeof_member(struct file_operations, read) read;
+
 		read = pde->proc_fops->read;
 		if (read)
 			rv = read(file, buf, count, ppos);
@@ -236,10 +228,11 @@
 
 static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
 {
-	ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	ssize_t rv = -EIO;
 	if (use_pde(pde)) {
+		typeof_member(struct file_operations, write) write;
+
 		write = pde->proc_fops->write;
 		if (write)
 			rv = write(file, buf, count, ppos);
@@ -252,8 +245,9 @@
 {
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	__poll_t rv = DEFAULT_POLLMASK;
-	__poll_t (*poll)(struct file *, struct poll_table_struct *);
 	if (use_pde(pde)) {
+		typeof_member(struct file_operations, poll) poll;
+
 		poll = pde->proc_fops->poll;
 		if (poll)
 			rv = poll(file, pts);
@@ -266,8 +260,9 @@
 {
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	long rv = -ENOTTY;
-	long (*ioctl)(struct file *, unsigned int, unsigned long);
 	if (use_pde(pde)) {
+		typeof_member(struct file_operations, unlocked_ioctl) ioctl;
+
 		ioctl = pde->proc_fops->unlocked_ioctl;
 		if (ioctl)
 			rv = ioctl(file, cmd, arg);
@@ -281,8 +276,9 @@
 {
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	long rv = -ENOTTY;
-	long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
 	if (use_pde(pde)) {
+		typeof_member(struct file_operations, compat_ioctl) compat_ioctl;
+
 		compat_ioctl = pde->proc_fops->compat_ioctl;
 		if (compat_ioctl)
 			rv = compat_ioctl(file, cmd, arg);
@@ -296,8 +292,9 @@
 {
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	int rv = -EIO;
-	int (*mmap)(struct file *, struct vm_area_struct *);
 	if (use_pde(pde)) {
+		typeof_member(struct file_operations, mmap) mmap;
+
 		mmap = pde->proc_fops->mmap;
 		if (mmap)
 			rv = mmap(file, vma);
@@ -315,7 +312,7 @@
 	unsigned long rv = -EIO;
 
 	if (use_pde(pde)) {
-		typeof(proc_reg_get_unmapped_area) *get_area;
+		typeof_member(struct file_operations, get_unmapped_area) get_area;
 
 		get_area = pde->proc_fops->get_unmapped_area;
 #ifdef CONFIG_MMU
@@ -336,8 +333,8 @@
 {
 	struct proc_dir_entry *pde = PDE(inode);
 	int rv = 0;
-	int (*open)(struct inode *, struct file *);
-	int (*release)(struct inode *, struct file *);
+	typeof_member(struct file_operations, open) open;
+	typeof_member(struct file_operations, release) release;
 	struct pde_opener *pdeo;
 
 	/*
@@ -490,48 +487,3 @@
 	       pde_put(de);
 	return inode;
 }
-
-int proc_fill_super(struct super_block *s, void *data, int silent)
-{
-	struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
-	struct inode *root_inode;
-	int ret;
-
-	if (!proc_parse_options(data, ns))
-		return -EINVAL;
-
-	/* User space would break if executables or devices appear on proc */
-	s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
-	s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC;
-	s->s_blocksize = 1024;
-	s->s_blocksize_bits = 10;
-	s->s_magic = PROC_SUPER_MAGIC;
-	s->s_op = &proc_sops;
-	s->s_time_gran = 1;
-
-	/*
-	 * procfs isn't actually a stacking filesystem; however, there is
-	 * too much magic going on inside it to permit stacking things on
-	 * top of it
-	 */
-	s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
-	
-	pde_get(&proc_root);
-	root_inode = proc_get_inode(s, &proc_root);
-	if (!root_inode) {
-		pr_err("proc_fill_super: get root inode failed\n");
-		return -ENOMEM;
-	}
-
-	s->s_root = d_make_root(root_inode);
-	if (!s->s_root) {
-		pr_err("proc_fill_super: allocate dentry failed\n");
-		return -ENOMEM;
-	}
-
-	ret = proc_setup_self(s);
-	if (ret) {
-		return ret;
-	}
-	return proc_setup_thread_self(s);
-}