/* * 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/printk.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 <linux/magic.h> #include <linux/uaccess.h> #include "internal.h" static void proc_evict_inode(struct inode *inode){ struct proc_dir_entry *de; struct ctl_table_header *head; truncate_inode_pages_final(&inode->i_data); clear_inode(inode); /* Stop tracking associated processes */ put_pid(PROC_I(inode)->pid); /* Let go of any associated proc directory entry */ de = PDE(inode); if (de) pde_put(de); head = PROC_I(inode)->sysctl; if (head) { RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL); proc_sys_evict_inode(inode, head); }} 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 = 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_ops = NULL; inode = &ei->vfs_inode; 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_ACCOUNT| 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 (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); if (pid->hide_pid != HIDEPID_OFF) 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,}; enum {BIAS = -1U<<31}; static inline int use_pde(struct proc_dir_entry *pde){ return atomic_inc_unless_negative(&pde->in_use);} static void unuse_pde(struct proc_dir_entry *pde){ if (atomic_dec_return(&pde->in_use) == BIAS) complete(pde->pde_unload_completion);} /* pde is locked */static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo){ /* * close() (proc_reg_release()) can't delete an entry and proceed: * ->release hook needs to be available at the right moment. * * rmmod (remove_proc_entry() et al) can't delete an entry and proceed: * "struct file" needs to be available at the right moment. * * Therefore, first process to enter this function does ->release() and * signals its completion to the other process which does nothing. */ if (pdeo->closing) { /* somebody else is doing that, just wait */ DECLARE_COMPLETION_ONSTACK(c); pdeo->c = &c; spin_unlock(&pde->pde_unload_lock); wait_for_completion(&c); spin_lock(&pde->pde_unload_lock); } else { struct file *file; pdeo->closing = true; spin_unlock(&pde->pde_unload_lock); file = pdeo->file; pde->proc_fops->release(file_inode(file), file); spin_lock(&pde->pde_unload_lock); /* After ->release. */ list_del(&pdeo->lh); if (pdeo->c) complete(pdeo->c); kfree(pdeo); }} void proc_entry_rundown(struct proc_dir_entry *de){ DECLARE_COMPLETION_ONSTACK(c); /* Wait until all existing callers into module are done. */ de->pde_unload_completion = &c; if (atomic_add_return(BIAS, &de->in_use) != BIAS) wait_for_completion(&c); /* ->pde_openers list can't grow from now on. */ spin_lock(&de->pde_unload_lock); while (!list_empty(&de->pde_openers)) { struct pde_opener *pdeo; pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); close_pdeo(de, pdeo); } spin_unlock(&de->pde_unload_lock);} static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence){ 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); llseek = pde->proc_fops->llseek; if (!llseek) llseek = default_llseek; rv = llseek(file, offset, whence); unuse_pde(pde); } return rv;} 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)) { read = pde->proc_fops->read; if (read) rv = read(file, buf, count, ppos); unuse_pde(pde); } return rv;} 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)) { write = pde->proc_fops->write; if (write) rv = write(file, buf, count, ppos); unuse_pde(pde); } return rv;} static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts){ struct proc_dir_entry *pde = PDE(file_inode(file)); unsigned int rv = DEFAULT_POLLMASK; unsigned int (*poll)(struct file *, struct poll_table_struct *); if (use_pde(pde)) { poll = pde->proc_fops->poll; if (poll) rv = poll(file, pts); unuse_pde(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_inode(file)); long rv = -ENOTTY; long (*ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { ioctl = pde->proc_fops->unlocked_ioctl; if (ioctl) rv = ioctl(file, cmd, arg); unuse_pde(pde); } return rv;} #ifdef CONFIG_COMPATstatic long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg){ 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)) { compat_ioctl = pde->proc_fops->compat_ioctl; if (compat_ioctl) rv = compat_ioctl(file, cmd, arg); unuse_pde(pde); } return rv;}#endif static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma){ struct proc_dir_entry *pde = PDE(file_inode(file)); int rv = -EIO; int (*mmap)(struct file *, struct vm_area_struct *); if (use_pde(pde)) { mmap = pde->proc_fops->mmap; if (mmap) rv = mmap(file, vma); unuse_pde(pde); } return rv;} static unsigned longproc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags){ struct proc_dir_entry *pde = PDE(file_inode(file)); unsigned long rv = -EIO; if (use_pde(pde)) { typeof(proc_reg_get_unmapped_area) *get_area; get_area = pde->proc_fops->get_unmapped_area;#ifdef CONFIG_MMU if (!get_area) get_area = current->mm->get_unmapped_area;#endif if (get_area) rv = get_area(file, orig_addr, len, pgoff, flags); else rv = orig_addr; unuse_pde(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; /* * Ensure that * 1) PDE's ->release hook will be called no matter what * either normally by close()/->release, or forcefully by * rmmod/remove_proc_entry. * * 2) rmmod isn't blocked by opening file in /proc and sitting on * the descriptor (including "rmmod foo </proc/foo" scenario). * * Save every "struct file" with custom ->release hook. */ pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL); if (!pdeo) return -ENOMEM; if (!use_pde(pde)) { kfree(pdeo); return -ENOENT; } open = pde->proc_fops->open; release = pde->proc_fops->release; if (open) rv = open(inode, file); if (rv == 0 && release) { /* To know what to release. */ pdeo->file = file; pdeo->closing = false; pdeo->c = NULL; spin_lock(&pde->pde_unload_lock); list_add(&pdeo->lh, &pde->pde_openers); spin_unlock(&pde->pde_unload_lock); } else kfree(pdeo); unuse_pde(pde); return rv;} static int proc_reg_release(struct inode *inode, struct file *file){ struct proc_dir_entry *pde = PDE(inode); struct pde_opener *pdeo; spin_lock(&pde->pde_unload_lock); list_for_each_entry(pdeo, &pde->pde_openers, lh) { if (pdeo->file == file) { close_pdeo(pde, pdeo); break; } } spin_unlock(&pde->pde_unload_lock); return 0;} 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, .get_unmapped_area = proc_reg_get_unmapped_area, .open = proc_reg_open, .release = proc_reg_release,}; #ifdef CONFIG_COMPATstatic 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, .get_unmapped_area = proc_reg_get_unmapped_area, .open = proc_reg_open, .release = proc_reg_release,};#endif static void proc_put_link(void *p){ unuse_pde(p);} static const char *proc_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done){ struct proc_dir_entry *pde = PDE(inode); if (unlikely(!use_pde(pde))) return ERR_PTR(-EINVAL); set_delayed_call(done, proc_put_link, pde); return pde->data;} const struct inode_operations proc_link_inode_operations = { .get_link = proc_get_link,}; struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de){ struct inode *inode = new_inode_pseudo(sb); if (inode) { inode->i_ino = de->low_ino; inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); PROC_I(inode)->pde = de; if (is_empty_pde(de)) { make_empty_dir_inode(inode); return inode; } 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); WARN_ON(!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; } } } else 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 |= 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; /* * 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);Lines 1–500 of 517. 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/* * 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/printk.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 <linux/magic.h> #include <linux/uaccess.h> #include "internal.h" static void proc_evict_inode(struct inode *inode) { struct proc_dir_entry *de; struct ctl_table_header *head; truncate_inode_pages_final(&inode->i_data); clear_inode(inode); /* Stop tracking associated processes */ put_pid(PROC_I(inode)->pid); /* Let go of any associated proc directory entry */ de = PDE(inode); if (de) pde_put(de); head = PROC_I(inode)->sysctl; if (head) { RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL); proc_sys_evict_inode(inode, head); } } 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 = 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_ops = NULL; inode = &ei->vfs_inode; 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_ACCOUNT| 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 (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); if (pid->hide_pid != HIDEPID_OFF) 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, }; enum {BIAS = -1U<<31}; static inline int use_pde(struct proc_dir_entry *pde) { return atomic_inc_unless_negative(&pde->in_use); } static void unuse_pde(struct proc_dir_entry *pde) { if (atomic_dec_return(&pde->in_use) == BIAS) complete(pde->pde_unload_completion); } /* pde is locked */ static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo) { /* * close() (proc_reg_release()) can't delete an entry and proceed: * ->release hook needs to be available at the right moment. * * rmmod (remove_proc_entry() et al) can't delete an entry and proceed: * "struct file" needs to be available at the right moment. * * Therefore, first process to enter this function does ->release() and * signals its completion to the other process which does nothing. */ if (pdeo->closing) { /* somebody else is doing that, just wait */ DECLARE_COMPLETION_ONSTACK(c); pdeo->c = &c; spin_unlock(&pde->pde_unload_lock); wait_for_completion(&c); spin_lock(&pde->pde_unload_lock); } else { struct file *file; pdeo->closing = true; spin_unlock(&pde->pde_unload_lock); file = pdeo->file; pde->proc_fops->release(file_inode(file), file); spin_lock(&pde->pde_unload_lock); /* After ->release. */ list_del(&pdeo->lh); if (pdeo->c) complete(pdeo->c); kfree(pdeo); } } void proc_entry_rundown(struct proc_dir_entry *de) { DECLARE_COMPLETION_ONSTACK(c); /* Wait until all existing callers into module are done. */ de->pde_unload_completion = &c; if (atomic_add_return(BIAS, &de->in_use) != BIAS) wait_for_completion(&c); /* ->pde_openers list can't grow from now on. */ spin_lock(&de->pde_unload_lock); while (!list_empty(&de->pde_openers)) { struct pde_opener *pdeo; pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); close_pdeo(de, pdeo); } spin_unlock(&de->pde_unload_lock); } static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) { 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); llseek = pde->proc_fops->llseek; if (!llseek) llseek = default_llseek; rv = llseek(file, offset, whence); unuse_pde(pde); } return rv; } 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)) { read = pde->proc_fops->read; if (read) rv = read(file, buf, count, ppos); unuse_pde(pde); } return rv; } 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)) { write = pde->proc_fops->write; if (write) rv = write(file, buf, count, ppos); unuse_pde(pde); } return rv; } static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts) { struct proc_dir_entry *pde = PDE(file_inode(file)); unsigned int rv = DEFAULT_POLLMASK; unsigned int (*poll)(struct file *, struct poll_table_struct *); if (use_pde(pde)) { poll = pde->proc_fops->poll; if (poll) rv = poll(file, pts); unuse_pde(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_inode(file)); long rv = -ENOTTY; long (*ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { ioctl = pde->proc_fops->unlocked_ioctl; if (ioctl) rv = ioctl(file, cmd, arg); unuse_pde(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_inode(file)); long rv = -ENOTTY; long (*compat_ioctl)(struct file *, unsigned int, unsigned long); if (use_pde(pde)) { compat_ioctl = pde->proc_fops->compat_ioctl; if (compat_ioctl) rv = compat_ioctl(file, cmd, arg); unuse_pde(pde); } return rv; } #endif static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) { struct proc_dir_entry *pde = PDE(file_inode(file)); int rv = -EIO; int (*mmap)(struct file *, struct vm_area_struct *); if (use_pde(pde)) { mmap = pde->proc_fops->mmap; if (mmap) rv = mmap(file, vma); unuse_pde(pde); } return rv; } static unsigned long proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct proc_dir_entry *pde = PDE(file_inode(file)); unsigned long rv = -EIO; if (use_pde(pde)) { typeof(proc_reg_get_unmapped_area) *get_area; get_area = pde->proc_fops->get_unmapped_area; #ifdef CONFIG_MMU if (!get_area) get_area = current->mm->get_unmapped_area; #endif if (get_area) rv = get_area(file, orig_addr, len, pgoff, flags); else rv = orig_addr; unuse_pde(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; /* * Ensure that * 1) PDE's ->release hook will be called no matter what * either normally by close()/->release, or forcefully by * rmmod/remove_proc_entry. * * 2) rmmod isn't blocked by opening file in /proc and sitting on * the descriptor (including "rmmod foo </proc/foo" scenario). * * Save every "struct file" with custom ->release hook. */ pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL); if (!pdeo) return -ENOMEM; if (!use_pde(pde)) { kfree(pdeo); return -ENOENT; } open = pde->proc_fops->open; release = pde->proc_fops->release; if (open) rv = open(inode, file); if (rv == 0 && release) { /* To know what to release. */ pdeo->file = file; pdeo->closing = false; pdeo->c = NULL; spin_lock(&pde->pde_unload_lock); list_add(&pdeo->lh, &pde->pde_openers); spin_unlock(&pde->pde_unload_lock); } else kfree(pdeo); unuse_pde(pde); return rv; } static int proc_reg_release(struct inode *inode, struct file *file) { struct proc_dir_entry *pde = PDE(inode); struct pde_opener *pdeo; spin_lock(&pde->pde_unload_lock); list_for_each_entry(pdeo, &pde->pde_openers, lh) { if (pdeo->file == file) { close_pdeo(pde, pdeo); break; } } spin_unlock(&pde->pde_unload_lock); return 0; } 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, .get_unmapped_area = proc_reg_get_unmapped_area, .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, .get_unmapped_area = proc_reg_get_unmapped_area, .open = proc_reg_open, .release = proc_reg_release, }; #endif static void proc_put_link(void *p) { unuse_pde(p); } static const char *proc_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { struct proc_dir_entry *pde = PDE(inode); if (unlikely(!use_pde(pde))) return ERR_PTR(-EINVAL); set_delayed_call(done, proc_put_link, pde); return pde->data; } const struct inode_operations proc_link_inode_operations = { .get_link = proc_get_link, }; struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) { struct inode *inode = new_inode_pseudo(sb); if (inode) { inode->i_ino = de->low_ino; inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); PROC_I(inode)->pde = de; if (is_empty_pde(de)) { make_empty_dir_inode(inode); return inode; } 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); WARN_ON(!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; } } } else 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 |= 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; /* * 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);