diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/proc/inode.c')
-rw-r--r-- | ANDROID_3.4.5/fs/proc/inode.c | 503 |
1 files changed, 503 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/proc/inode.c b/ANDROID_3.4.5/fs/proc/inode.c new file mode 100644 index 00000000..205c9228 --- /dev/null +++ b/ANDROID_3.4.5/fs/proc/inode.c @@ -0,0 +1,503 @@ +/* + * 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/pid_namespace.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/sysctl.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/mount.h> + +#include <asm/uaccess.h> + +#include "internal.h" + +static void proc_evict_inode(struct inode *inode) +{ + struct proc_dir_entry *de; + struct ctl_table_header *head; + const struct proc_ns_operations *ns_ops; + + truncate_inode_pages(&inode->i_data, 0); + end_writeback(inode); + + /* 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) + pde_put(de); + head = PROC_I(inode)->sysctl; + if (head) { + rcu_assign_pointer(PROC_I(inode)->sysctl, NULL); + sysctl_head_put(head); + } + /* Release any associated namespace */ + ns_ops = PROC_I(inode)->ns_ops; + if (ns_ops && ns_ops->put) + ns_ops->put(PROC_I(inode)->ns); +} + +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; + ei->sysctl = NULL; + ei->sysctl_entry = NULL; + ei->ns = NULL; + ei->ns_ops = NULL; + inode = &ei->vfs_inode; + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; + return inode; +} + +static void proc_i_callback(struct rcu_head *head) +{ + 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; + + inode_init_once(&ei->vfs_inode); +} + +void __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); +} + +static int proc_show_options(struct seq_file *seq, struct dentry *root) +{ + struct super_block *sb = root->d_sb; + struct pid_namespace *pid = sb->s_fs_info; + + if (pid->pid_gid) + seq_printf(seq, ",gid=%lu", (unsigned long)pid->pid_gid); + if (pid->hide_pid != 0) + seq_printf(seq, ",hidepid=%u", pid->hide_pid); + + return 0; +} + +static const struct super_operations proc_sops = { + .alloc_inode = proc_alloc_inode, + .destroy_inode = proc_destroy_inode, + .drop_inode = generic_delete_inode, + .evict_inode = proc_evict_inode, + .statfs = simple_statfs, + .remount_fs = proc_remount, + .show_options = proc_show_options, +}; + +static void __pde_users_dec(struct proc_dir_entry *pde) +{ + pde->pde_users--; + if (pde->pde_unload_completion && pde->pde_users == 0) + complete(pde->pde_unload_completion); +} + +void pde_users_dec(struct proc_dir_entry *pde) +{ + spin_lock(&pde->pde_unload_lock); + __pde_users_dec(pde); + 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 (*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++; + ioctl = pde->proc_fops->unlocked_ioctl; + spin_unlock(&pde->pde_unload_lock); + + if (ioctl) + rv = ioctl(file, cmd, arg); + + 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 *); + int (*release)(struct inode *, struct file *); + struct pde_opener *pdeo; + + /* + * What for, you ask? Well, we can have open, rmmod, remove_proc_entry + * sequence. ->release won't be called because ->proc_fops will be + * cleared. Depending on complexity of ->release, consequences vary. + * + * We can't wait for mercy when close will be done for real, it's + * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release + * by hand in remove_proc_entry(). For this, save opener's credentials + * for later. + */ + pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL); + if (!pdeo) + return -ENOMEM; + + spin_lock(&pde->pde_unload_lock); + if (!pde->proc_fops) { + spin_unlock(&pde->pde_unload_lock); + kfree(pdeo); + return -ENOENT; + } + pde->pde_users++; + open = pde->proc_fops->open; + release = pde->proc_fops->release; + spin_unlock(&pde->pde_unload_lock); + + if (open) + rv = open(inode, file); + + spin_lock(&pde->pde_unload_lock); + if (rv == 0 && release) { + /* To know what to release. */ + pdeo->inode = inode; + pdeo->file = file; + /* Strictly for "too late" ->release in proc_reg_release(). */ + pdeo->release = release; + list_add(&pdeo->lh, &pde->pde_openers); + } else + kfree(pdeo); + __pde_users_dec(pde); + spin_unlock(&pde->pde_unload_lock); + return rv; +} + +static struct pde_opener *find_pde_opener(struct proc_dir_entry *pde, + struct inode *inode, struct file *file) +{ + struct pde_opener *pdeo; + + list_for_each_entry(pdeo, &pde->pde_openers, lh) { + if (pdeo->inode == inode && pdeo->file == file) + return pdeo; + } + return NULL; +} + +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 *); + struct pde_opener *pdeo; + + spin_lock(&pde->pde_unload_lock); + pdeo = find_pde_opener(pde, inode, file); + if (!pde->proc_fops) { + /* + * Can't simply exit, __fput() will think that everything is OK, + * and move on to freeing struct file. remove_proc_entry() will + * find slacker in opener's list and will try to do non-trivial + * things with struct file. Therefore, remove opener from list. + * + * But if opener is removed from list, who will ->release it? + */ + if (pdeo) { + list_del(&pdeo->lh); + spin_unlock(&pde->pde_unload_lock); + rv = pdeo->release(inode, file); + kfree(pdeo); + } else + spin_unlock(&pde->pde_unload_lock); + return rv; + } + pde->pde_users++; + release = pde->proc_fops->release; + if (pdeo) { + list_del(&pdeo->lh); + kfree(pdeo); + } + 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, struct proc_dir_entry *de) +{ + struct inode * inode; + + inode = iget_locked(sb, de->low_ino); + if (!inode) + return NULL; + if (inode->i_state & I_NEW) { + inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; + PROC_I(inode)->fd = 0; + PROC_I(inode)->pde = 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) + set_nlink(inode, 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; + } + } + unlock_new_inode(inode); + } else + pde_put(de); + return inode; +} + +int proc_fill_super(struct super_block *s) +{ + 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; + + pde_get(&proc_root); + s->s_root = d_make_root(proc_get_inode(s, &proc_root)); + if (s->s_root) + return 0; + + printk("proc_read_super: get root inode failed\n"); + pde_put(&proc_root); + return -ENOMEM; +} |