You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
474 lines
10 KiB
474 lines
10 KiB
/*
|
|
* linux/fs/proc/inode.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*/
|
|
|
|
#include <linux/time.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/string.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/completion.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/file.h>
|
|
#include <linux/limits.h>
|
|
#include <linux/init.h>
|
|
#include <linux/module.h>
|
|
#include <linux/smp_lock.h>
|
|
|
|
#include <asm/system.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
#include "internal.h"
|
|
|
|
struct proc_dir_entry *de_get(struct proc_dir_entry *de)
|
|
{
|
|
if (de)
|
|
atomic_inc(&de->count);
|
|
return de;
|
|
}
|
|
|
|
/*
|
|
* Decrements the use count and checks for deferred deletion.
|
|
*/
|
|
void de_put(struct proc_dir_entry *de)
|
|
{
|
|
if (de) {
|
|
lock_kernel();
|
|
if (!atomic_read(&de->count)) {
|
|
printk("de_put: entry %s already free!\n", de->name);
|
|
unlock_kernel();
|
|
return;
|
|
}
|
|
|
|
if (atomic_dec_and_test(&de->count))
|
|
free_proc_entry(de);
|
|
unlock_kernel();
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Decrement the use count of the proc_dir_entry.
|
|
*/
|
|
static void proc_delete_inode(struct inode *inode)
|
|
{
|
|
struct proc_dir_entry *de;
|
|
|
|
truncate_inode_pages(&inode->i_data, 0);
|
|
|
|
/* Stop tracking associated processes */
|
|
put_pid(PROC_I(inode)->pid);
|
|
|
|
/* Let go of any associated proc directory entry */
|
|
de = PROC_I(inode)->pde;
|
|
if (de) {
|
|
if (de->owner)
|
|
module_put(de->owner);
|
|
de_put(de);
|
|
}
|
|
clear_inode(inode);
|
|
}
|
|
|
|
struct vfsmount *proc_mnt;
|
|
|
|
static void proc_read_inode(struct inode * inode)
|
|
{
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
|
|
}
|
|
|
|
static struct kmem_cache * proc_inode_cachep;
|
|
|
|
static struct inode *proc_alloc_inode(struct super_block *sb)
|
|
{
|
|
struct proc_inode *ei;
|
|
struct inode *inode;
|
|
|
|
ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
|
|
if (!ei)
|
|
return NULL;
|
|
ei->pid = NULL;
|
|
ei->fd = 0;
|
|
ei->op.proc_get_link = NULL;
|
|
ei->pde = NULL;
|
|
inode = &ei->vfs_inode;
|
|
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
|
|
return inode;
|
|
}
|
|
|
|
static void proc_destroy_inode(struct inode *inode)
|
|
{
|
|
kmem_cache_free(proc_inode_cachep, PROC_I(inode));
|
|
}
|
|
|
|
static void init_once(struct kmem_cache * cachep, void *foo)
|
|
{
|
|
struct proc_inode *ei = (struct proc_inode *) foo;
|
|
|
|
inode_init_once(&ei->vfs_inode);
|
|
}
|
|
|
|
int __init proc_init_inodecache(void)
|
|
{
|
|
proc_inode_cachep = kmem_cache_create("proc_inode_cache",
|
|
sizeof(struct proc_inode),
|
|
0, (SLAB_RECLAIM_ACCOUNT|
|
|
SLAB_MEM_SPREAD|SLAB_PANIC),
|
|
init_once);
|
|
return 0;
|
|
}
|
|
|
|
static int proc_remount(struct super_block *sb, int *flags, char *data)
|
|
{
|
|
*flags |= MS_NODIRATIME;
|
|
return 0;
|
|
}
|
|
|
|
static const struct super_operations proc_sops = {
|
|
.alloc_inode = proc_alloc_inode,
|
|
.destroy_inode = proc_destroy_inode,
|
|
.read_inode = proc_read_inode,
|
|
.drop_inode = generic_delete_inode,
|
|
.delete_inode = proc_delete_inode,
|
|
.statfs = simple_statfs,
|
|
.remount_fs = proc_remount,
|
|
};
|
|
|
|
static void pde_users_dec(struct proc_dir_entry *pde)
|
|
{
|
|
spin_lock(&pde->pde_unload_lock);
|
|
pde->pde_users--;
|
|
if (pde->pde_unload_completion && pde->pde_users == 0)
|
|
complete(pde->pde_unload_completion);
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
}
|
|
|
|
static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
loff_t rv = -EINVAL;
|
|
loff_t (*llseek)(struct file *, loff_t, int);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
/*
|
|
* remove_proc_entry() is going to delete PDE (as part of module
|
|
* cleanup sequence). No new callers into module allowed.
|
|
*/
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
/*
|
|
* Bump refcount so that remove_proc_entry will wail for ->llseek to
|
|
* complete.
|
|
*/
|
|
pde->pde_users++;
|
|
/*
|
|
* Save function pointer under lock, to protect against ->proc_fops
|
|
* NULL'ifying right after ->pde_unload_lock is dropped.
|
|
*/
|
|
llseek = pde->proc_fops->llseek;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (!llseek)
|
|
llseek = default_llseek;
|
|
rv = llseek(file, offset, whence);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
ssize_t rv = -EIO;
|
|
ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
read = pde->proc_fops->read;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (read)
|
|
rv = read(file, buf, count, ppos);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
ssize_t rv = -EIO;
|
|
ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
write = pde->proc_fops->write;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (write)
|
|
rv = write(file, buf, count, ppos);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
unsigned int rv = DEFAULT_POLLMASK;
|
|
unsigned int (*poll)(struct file *, struct poll_table_struct *);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
poll = pde->proc_fops->poll;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (poll)
|
|
rv = poll(file, pts);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
long rv = -ENOTTY;
|
|
long (*unlocked_ioctl)(struct file *, unsigned int, unsigned long);
|
|
int (*ioctl)(struct inode *, struct file *, unsigned int, unsigned long);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
unlocked_ioctl = pde->proc_fops->unlocked_ioctl;
|
|
ioctl = pde->proc_fops->ioctl;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (unlocked_ioctl) {
|
|
rv = unlocked_ioctl(file, cmd, arg);
|
|
if (rv == -ENOIOCTLCMD)
|
|
rv = -EINVAL;
|
|
} else if (ioctl) {
|
|
lock_kernel();
|
|
rv = ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
|
|
unlock_kernel();
|
|
}
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
long rv = -ENOTTY;
|
|
long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
compat_ioctl = pde->proc_fops->compat_ioctl;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (compat_ioctl)
|
|
rv = compat_ioctl(file, cmd, arg);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
#endif
|
|
|
|
static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
|
|
int rv = -EIO;
|
|
int (*mmap)(struct file *, struct vm_area_struct *);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
mmap = pde->proc_fops->mmap;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (mmap)
|
|
rv = mmap(file, vma);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static int proc_reg_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(inode);
|
|
int rv = 0;
|
|
int (*open)(struct inode *, struct file *);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
open = pde->proc_fops->open;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (open)
|
|
rv = open(inode, file);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static int proc_reg_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct proc_dir_entry *pde = PDE(inode);
|
|
int rv = 0;
|
|
int (*release)(struct inode *, struct file *);
|
|
|
|
spin_lock(&pde->pde_unload_lock);
|
|
if (!pde->proc_fops) {
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
return rv;
|
|
}
|
|
pde->pde_users++;
|
|
release = pde->proc_fops->release;
|
|
spin_unlock(&pde->pde_unload_lock);
|
|
|
|
if (release)
|
|
rv = release(inode, file);
|
|
|
|
pde_users_dec(pde);
|
|
return rv;
|
|
}
|
|
|
|
static const struct file_operations proc_reg_file_ops = {
|
|
.llseek = proc_reg_llseek,
|
|
.read = proc_reg_read,
|
|
.write = proc_reg_write,
|
|
.poll = proc_reg_poll,
|
|
.unlocked_ioctl = proc_reg_unlocked_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = proc_reg_compat_ioctl,
|
|
#endif
|
|
.mmap = proc_reg_mmap,
|
|
.open = proc_reg_open,
|
|
.release = proc_reg_release,
|
|
};
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
static const struct file_operations proc_reg_file_ops_no_compat = {
|
|
.llseek = proc_reg_llseek,
|
|
.read = proc_reg_read,
|
|
.write = proc_reg_write,
|
|
.poll = proc_reg_poll,
|
|
.unlocked_ioctl = proc_reg_unlocked_ioctl,
|
|
.mmap = proc_reg_mmap,
|
|
.open = proc_reg_open,
|
|
.release = proc_reg_release,
|
|
};
|
|
#endif
|
|
|
|
struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
|
|
struct proc_dir_entry *de)
|
|
{
|
|
struct inode * inode;
|
|
|
|
if (de != NULL && !try_module_get(de->owner))
|
|
goto out_mod;
|
|
|
|
inode = iget(sb, ino);
|
|
if (!inode)
|
|
goto out_ino;
|
|
|
|
PROC_I(inode)->fd = 0;
|
|
PROC_I(inode)->pde = de;
|
|
if (de) {
|
|
if (de->mode) {
|
|
inode->i_mode = de->mode;
|
|
inode->i_uid = de->uid;
|
|
inode->i_gid = de->gid;
|
|
}
|
|
if (de->size)
|
|
inode->i_size = de->size;
|
|
if (de->nlink)
|
|
inode->i_nlink = de->nlink;
|
|
if (de->proc_iops)
|
|
inode->i_op = de->proc_iops;
|
|
if (de->proc_fops) {
|
|
if (S_ISREG(inode->i_mode)) {
|
|
#ifdef CONFIG_COMPAT
|
|
if (!de->proc_fops->compat_ioctl)
|
|
inode->i_fop =
|
|
&proc_reg_file_ops_no_compat;
|
|
else
|
|
#endif
|
|
inode->i_fop = &proc_reg_file_ops;
|
|
}
|
|
else
|
|
inode->i_fop = de->proc_fops;
|
|
}
|
|
}
|
|
|
|
return inode;
|
|
|
|
out_ino:
|
|
if (de != NULL)
|
|
module_put(de->owner);
|
|
out_mod:
|
|
return NULL;
|
|
}
|
|
|
|
int proc_fill_super(struct super_block *s)
|
|
{
|
|
struct inode * root_inode;
|
|
|
|
s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_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;
|
|
|
|
de_get(&proc_root);
|
|
root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root);
|
|
if (!root_inode)
|
|
goto out_no_root;
|
|
root_inode->i_uid = 0;
|
|
root_inode->i_gid = 0;
|
|
s->s_root = d_alloc_root(root_inode);
|
|
if (!s->s_root)
|
|
goto out_no_root;
|
|
return 0;
|
|
|
|
out_no_root:
|
|
printk("proc_read_super: get root inode failed\n");
|
|
iput(root_inode);
|
|
de_put(&proc_root);
|
|
return -ENOMEM;
|
|
}
|
|
MODULE_LICENSE("GPL");
|
|
|