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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/proc/inode.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7#include <linux/time.h>
8#include <linux/proc_fs.h>
9#include <linux/kernel.h>
Vasiliy Kulikov97412952012-01-10 15:11:27 -080010#include <linux/pid_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/mm.h>
12#include <linux/string.h>
13#include <linux/stat.h>
Alexey Dobriyan786d7e12007-07-15 23:39:00 -070014#include <linux/completion.h>
Alexey Dobriyandd23aae2007-09-11 15:23:55 -070015#include <linux/poll.h>
Andrew Morton87ebdc02013-02-27 17:03:16 -080016#include <linux/printk.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/file.h>
18#include <linux/limits.h>
19#include <linux/init.h>
20#include <linux/module.h>
Al Viro9043476f2008-07-15 08:54:06 -040021#include <linux/sysctl.h>
Vasiliy Kulikov97412952012-01-10 15:11:27 -080022#include <linux/seq_file.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Vasiliy Kulikov97412952012-01-10 15:11:27 -080024#include <linux/mount.h>
David Howells303eb7e2013-04-11 23:55:54 +010025#include <linux/magic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <asm/uaccess.h>
28
Adrian Bunkfee781e2006-01-08 01:04:16 -080029#include "internal.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Al Viro82679522010-06-04 22:17:56 -040031static void proc_evict_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032{
33 struct proc_dir_entry *de;
Al Virodfef6dcd32011-03-08 01:25:28 -050034 struct ctl_table_header *head;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Johannes Weiner91b0abe2014-04-03 14:47:49 -070036 truncate_inode_pages_final(&inode->i_data);
Jan Karadbd57682012-05-03 14:48:02 +020037 clear_inode(inode);
Mark Fashehfef26652005-09-09 13:01:31 -070038
Eric W. Biederman99f89552006-06-26 00:25:55 -070039 /* Stop tracking associated processes */
Eric W. Biederman13b41b02006-06-26 00:25:56 -070040 put_pid(PROC_I(inode)->pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42 /* Let go of any associated proc directory entry */
Alexander Kuleshov6bee55f2015-02-12 15:01:03 -080043 de = PDE(inode);
Alexey Dobriyan99b76232009-03-25 22:48:06 +030044 if (de)
Alexey Dobriyan135d5652009-12-15 16:45:39 -080045 pde_put(de);
Al Virodfef6dcd32011-03-08 01:25:28 -050046 head = PROC_I(inode)->sysctl;
47 if (head) {
Monam Agarwal1c44dbc2014-04-07 15:38:35 -070048 RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
Al Virodfef6dcd32011-03-08 01:25:28 -050049 sysctl_head_put(head);
50 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070051}
52
Christoph Lametere18b8902006-12-06 20:33:20 -080053static struct kmem_cache * proc_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55static struct inode *proc_alloc_inode(struct super_block *sb)
56{
57 struct proc_inode *ei;
58 struct inode *inode;
59
Christoph Lametere94b1762006-12-06 20:33:17 -080060 ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 if (!ei)
62 return NULL;
Eric W. Biederman13b41b02006-06-26 00:25:56 -070063 ei->pid = NULL;
Eric W. Biedermanaed7a6c2006-06-26 00:25:44 -070064 ei->fd = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 ei->op.proc_get_link = NULL;
66 ei->pde = NULL;
Al Viro9043476f2008-07-15 08:54:06 -040067 ei->sysctl = NULL;
68 ei->sysctl_entry = NULL;
Al Viro3d3d35b2014-11-01 11:10:28 -040069 ei->ns_ops = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 inode = &ei->vfs_inode;
71 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
72 return inode;
73}
74
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +110075static void proc_i_callback(struct rcu_head *head)
76{
77 struct inode *inode = container_of(head, struct inode, i_rcu);
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +110078 kmem_cache_free(proc_inode_cachep, PROC_I(inode));
79}
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081static void proc_destroy_inode(struct inode *inode)
82{
Nick Pigginfa0d7e3d2011-01-07 17:49:49 +110083 call_rcu(&inode->i_rcu, proc_i_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084}
85
Alexey Dobriyan51cc5062008-07-25 19:45:34 -070086static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
88 struct proc_inode *ei = (struct proc_inode *) foo;
89
Christoph Lametera35afb82007-05-16 22:10:57 -070090 inode_init_once(&ei->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091}
Paul Mundt20c2df82007-07-20 10:11:58 +090092
Alexey Dobriyan5bcd7ff2008-10-17 03:43:55 +040093void __init proc_init_inodecache(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
95 proc_inode_cachep = kmem_cache_create("proc_inode_cache",
96 sizeof(struct proc_inode),
Paul Jacksonfffb60f2006-03-24 03:16:06 -080097 0, (SLAB_RECLAIM_ACCOUNT|
Vladimir Davydov5d097052016-01-14 15:18:21 -080098 SLAB_MEM_SPREAD|SLAB_ACCOUNT|
99 SLAB_PANIC),
Paul Mundt20c2df82007-07-20 10:11:58 +0900100 init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101}
102
Vasiliy Kulikov97412952012-01-10 15:11:27 -0800103static int proc_show_options(struct seq_file *seq, struct dentry *root)
104{
Vasiliy Kulikov04996802012-01-10 15:11:31 -0800105 struct super_block *sb = root->d_sb;
106 struct pid_namespace *pid = sb->s_fs_info;
107
Eric W. Biedermandcb0f222012-02-09 08:48:21 -0800108 if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
109 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
Vasiliy Kulikov04996802012-01-10 15:11:31 -0800110 if (pid->hide_pid != 0)
111 seq_printf(seq, ",hidepid=%u", pid->hide_pid);
112
Vasiliy Kulikov97412952012-01-10 15:11:27 -0800113 return 0;
114}
115
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800116static const struct super_operations proc_sops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 .alloc_inode = proc_alloc_inode,
118 .destroy_inode = proc_destroy_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 .drop_inode = generic_delete_inode,
Al Viro82679522010-06-04 22:17:56 -0400120 .evict_inode = proc_evict_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 .statfs = simple_statfs,
Vasiliy Kulikov97412952012-01-10 15:11:27 -0800122 .remount_fs = proc_remount,
123 .show_options = proc_show_options,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124};
125
Al Viro866ad9a2013-04-03 19:07:30 -0400126enum {BIAS = -1U<<31};
127
128static inline int use_pde(struct proc_dir_entry *pde)
129{
Al Viro05c0ae22013-04-04 16:28:47 -0400130 return atomic_inc_unless_negative(&pde->in_use);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700131}
132
Al Viro866ad9a2013-04-03 19:07:30 -0400133static void unuse_pde(struct proc_dir_entry *pde)
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700134{
Al Viro05c0ae22013-04-04 16:28:47 -0400135 if (atomic_dec_return(&pde->in_use) == BIAS)
136 complete(pde->pde_unload_completion);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700137}
138
Al Viroca469f32013-04-03 19:57:00 -0400139/* pde is locked */
140static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
141{
Al Viro05c0ae22013-04-04 16:28:47 -0400142 if (pdeo->closing) {
Al Viroca469f32013-04-03 19:57:00 -0400143 /* somebody else is doing that, just wait */
Al Viro05c0ae22013-04-04 16:28:47 -0400144 DECLARE_COMPLETION_ONSTACK(c);
145 pdeo->c = &c;
Al Viroca469f32013-04-03 19:57:00 -0400146 spin_unlock(&pde->pde_unload_lock);
Al Viro05c0ae22013-04-04 16:28:47 -0400147 wait_for_completion(&c);
Al Viroca469f32013-04-03 19:57:00 -0400148 spin_lock(&pde->pde_unload_lock);
Al Viroca469f32013-04-03 19:57:00 -0400149 } else {
150 struct file *file;
Al Viro05c0ae22013-04-04 16:28:47 -0400151 pdeo->closing = 1;
Al Viroca469f32013-04-03 19:57:00 -0400152 spin_unlock(&pde->pde_unload_lock);
153 file = pdeo->file;
154 pde->proc_fops->release(file_inode(file), file);
155 spin_lock(&pde->pde_unload_lock);
156 list_del_init(&pdeo->lh);
Al Viro05c0ae22013-04-04 16:28:47 -0400157 if (pdeo->c)
158 complete(pdeo->c);
Al Viroca469f32013-04-03 19:57:00 -0400159 kfree(pdeo);
Al Viro05c0ae22013-04-04 16:28:47 -0400160 }
Al Viroca469f32013-04-03 19:57:00 -0400161}
162
Al Viro866ad9a2013-04-03 19:07:30 -0400163void proc_entry_rundown(struct proc_dir_entry *de)
164{
Al Viro05c0ae22013-04-04 16:28:47 -0400165 DECLARE_COMPLETION_ONSTACK(c);
Al Viro866ad9a2013-04-03 19:07:30 -0400166 /* Wait until all existing callers into module are done. */
Al Viro05c0ae22013-04-04 16:28:47 -0400167 de->pde_unload_completion = &c;
168 if (atomic_add_return(BIAS, &de->in_use) != BIAS)
169 wait_for_completion(&c);
Al Viro866ad9a2013-04-03 19:07:30 -0400170
Al Viro05c0ae22013-04-04 16:28:47 -0400171 spin_lock(&de->pde_unload_lock);
Al Viro866ad9a2013-04-03 19:07:30 -0400172 while (!list_empty(&de->pde_openers)) {
173 struct pde_opener *pdeo;
Al Viro866ad9a2013-04-03 19:07:30 -0400174 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
Al Viroca469f32013-04-03 19:57:00 -0400175 close_pdeo(de, pdeo);
Al Viro866ad9a2013-04-03 19:07:30 -0400176 }
177 spin_unlock(&de->pde_unload_lock);
178}
179
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700180static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
181{
Al Viro496ad9a2013-01-23 17:07:38 -0500182 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700183 loff_t rv = -EINVAL;
Al Viro866ad9a2013-04-03 19:07:30 -0400184 if (use_pde(pde)) {
185 loff_t (*llseek)(struct file *, loff_t, int);
186 llseek = pde->proc_fops->llseek;
187 if (!llseek)
188 llseek = default_llseek;
189 rv = llseek(file, offset, whence);
190 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700191 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700192 return rv;
193}
194
195static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
196{
Al Viro866ad9a2013-04-03 19:07:30 -0400197 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
Al Viro496ad9a2013-01-23 17:07:38 -0500198 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700199 ssize_t rv = -EIO;
Al Viro866ad9a2013-04-03 19:07:30 -0400200 if (use_pde(pde)) {
201 read = pde->proc_fops->read;
202 if (read)
203 rv = read(file, buf, count, ppos);
204 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700205 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700206 return rv;
207}
208
209static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
210{
Al Viro866ad9a2013-04-03 19:07:30 -0400211 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
Al Viro496ad9a2013-01-23 17:07:38 -0500212 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700213 ssize_t rv = -EIO;
Al Viro866ad9a2013-04-03 19:07:30 -0400214 if (use_pde(pde)) {
215 write = pde->proc_fops->write;
216 if (write)
217 rv = write(file, buf, count, ppos);
218 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700219 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700220 return rv;
221}
222
223static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
224{
Al Viro496ad9a2013-01-23 17:07:38 -0500225 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyandd23aae2007-09-11 15:23:55 -0700226 unsigned int rv = DEFAULT_POLLMASK;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700227 unsigned int (*poll)(struct file *, struct poll_table_struct *);
Al Viro866ad9a2013-04-03 19:07:30 -0400228 if (use_pde(pde)) {
229 poll = pde->proc_fops->poll;
230 if (poll)
231 rv = poll(file, pts);
232 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700233 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700234 return rv;
235}
236
237static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
238{
Al Viro496ad9a2013-01-23 17:07:38 -0500239 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700240 long rv = -ENOTTY;
Arnd Bergmannb19dd422010-07-04 00:15:10 +0200241 long (*ioctl)(struct file *, unsigned int, unsigned long);
Al Viro866ad9a2013-04-03 19:07:30 -0400242 if (use_pde(pde)) {
243 ioctl = pde->proc_fops->unlocked_ioctl;
244 if (ioctl)
245 rv = ioctl(file, cmd, arg);
246 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700247 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700248 return rv;
249}
250
251#ifdef CONFIG_COMPAT
252static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
253{
Al Viro496ad9a2013-01-23 17:07:38 -0500254 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700255 long rv = -ENOTTY;
256 long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
Al Viro866ad9a2013-04-03 19:07:30 -0400257 if (use_pde(pde)) {
258 compat_ioctl = pde->proc_fops->compat_ioctl;
259 if (compat_ioctl)
260 rv = compat_ioctl(file, cmd, arg);
261 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700262 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700263 return rv;
264}
265#endif
266
267static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
268{
Al Viro496ad9a2013-01-23 17:07:38 -0500269 struct proc_dir_entry *pde = PDE(file_inode(file));
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700270 int rv = -EIO;
271 int (*mmap)(struct file *, struct vm_area_struct *);
Al Viro866ad9a2013-04-03 19:07:30 -0400272 if (use_pde(pde)) {
273 mmap = pde->proc_fops->mmap;
274 if (mmap)
275 rv = mmap(file, vma);
276 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700277 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700278 return rv;
279}
280
HATAYAMA Daisuke5721cf82013-11-12 15:11:15 -0800281static unsigned long
282proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr,
283 unsigned long len, unsigned long pgoff,
284 unsigned long flags)
Alexey Dobriyanc4fe2442013-08-20 22:17:24 +0300285{
286 struct proc_dir_entry *pde = PDE(file_inode(file));
HATAYAMA Daisuke2cbe3b02013-10-16 13:47:04 -0700287 unsigned long rv = -EIO;
Jan Beulichae5758a2013-12-12 17:12:22 -0800288
Alexey Dobriyanc4fe2442013-08-20 22:17:24 +0300289 if (use_pde(pde)) {
Jan Beulichae5758a2013-12-12 17:12:22 -0800290 typeof(proc_reg_get_unmapped_area) *get_area;
291
292 get_area = pde->proc_fops->get_unmapped_area;
HATAYAMA Daisukefad1a862013-10-16 13:47:05 -0700293#ifdef CONFIG_MMU
Jan Beulichae5758a2013-12-12 17:12:22 -0800294 if (!get_area)
295 get_area = current->mm->get_unmapped_area;
HATAYAMA Daisukefad1a862013-10-16 13:47:05 -0700296#endif
Jan Beulichae5758a2013-12-12 17:12:22 -0800297
HATAYAMA Daisuke5721cf82013-11-12 15:11:15 -0800298 if (get_area)
299 rv = get_area(file, orig_addr, len, pgoff, flags);
Jan Beulichae5758a2013-12-12 17:12:22 -0800300 else
301 rv = orig_addr;
Alexey Dobriyanc4fe2442013-08-20 22:17:24 +0300302 unuse_pde(pde);
303 }
304 return rv;
305}
306
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700307static int proc_reg_open(struct inode *inode, struct file *file)
308{
309 struct proc_dir_entry *pde = PDE(inode);
310 int rv = 0;
311 int (*open)(struct inode *, struct file *);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700312 int (*release)(struct inode *, struct file *);
313 struct pde_opener *pdeo;
314
315 /*
316 * What for, you ask? Well, we can have open, rmmod, remove_proc_entry
317 * sequence. ->release won't be called because ->proc_fops will be
318 * cleared. Depending on complexity of ->release, consequences vary.
319 *
320 * We can't wait for mercy when close will be done for real, it's
321 * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release
322 * by hand in remove_proc_entry(). For this, save opener's credentials
323 * for later.
324 */
Al Viro05c0ae22013-04-04 16:28:47 -0400325 pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700326 if (!pdeo)
327 return -ENOMEM;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700328
Al Viro866ad9a2013-04-03 19:07:30 -0400329 if (!use_pde(pde)) {
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700330 kfree(pdeo);
Daisuke Oginod2857e72011-07-26 16:08:37 -0700331 return -ENOENT;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700332 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700333 open = pde->proc_fops->open;
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700334 release = pde->proc_fops->release;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700335
336 if (open)
337 rv = open(inode, file);
338
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700339 if (rv == 0 && release) {
340 /* To know what to release. */
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700341 pdeo->file = file;
342 /* Strictly for "too late" ->release in proc_reg_release(). */
Al Viro05c0ae22013-04-04 16:28:47 -0400343 spin_lock(&pde->pde_unload_lock);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700344 list_add(&pdeo->lh, &pde->pde_openers);
Al Viro05c0ae22013-04-04 16:28:47 -0400345 spin_unlock(&pde->pde_unload_lock);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700346 } else
347 kfree(pdeo);
Al Viro05c0ae22013-04-04 16:28:47 -0400348
349 unuse_pde(pde);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700350 return rv;
351}
352
353static int proc_reg_release(struct inode *inode, struct file *file)
354{
355 struct proc_dir_entry *pde = PDE(inode);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700356 struct pde_opener *pdeo;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700357 spin_lock(&pde->pde_unload_lock);
Al Viroca469f32013-04-03 19:57:00 -0400358 list_for_each_entry(pdeo, &pde->pde_openers, lh) {
359 if (pdeo->file == file) {
360 close_pdeo(pde, pdeo);
361 break;
362 }
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700363 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700364 spin_unlock(&pde->pde_unload_lock);
Al Viroca469f32013-04-03 19:57:00 -0400365 return 0;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700366}
367
368static const struct file_operations proc_reg_file_ops = {
369 .llseek = proc_reg_llseek,
370 .read = proc_reg_read,
371 .write = proc_reg_write,
372 .poll = proc_reg_poll,
373 .unlocked_ioctl = proc_reg_unlocked_ioctl,
374#ifdef CONFIG_COMPAT
375 .compat_ioctl = proc_reg_compat_ioctl,
376#endif
377 .mmap = proc_reg_mmap,
Alexey Dobriyanc4fe2442013-08-20 22:17:24 +0300378 .get_unmapped_area = proc_reg_get_unmapped_area,
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700379 .open = proc_reg_open,
380 .release = proc_reg_release,
381};
382
David Miller778f3dd2007-07-27 22:58:37 -0700383#ifdef CONFIG_COMPAT
384static const struct file_operations proc_reg_file_ops_no_compat = {
385 .llseek = proc_reg_llseek,
386 .read = proc_reg_read,
387 .write = proc_reg_write,
388 .poll = proc_reg_poll,
389 .unlocked_ioctl = proc_reg_unlocked_ioctl,
390 .mmap = proc_reg_mmap,
Alexey Dobriyanc4fe2442013-08-20 22:17:24 +0300391 .get_unmapped_area = proc_reg_get_unmapped_area,
David Miller778f3dd2007-07-27 22:58:37 -0700392 .open = proc_reg_open,
393 .release = proc_reg_release,
394};
395#endif
396
Al Virofceef392015-12-29 15:58:39 -0500397static void proc_put_link(void *p)
398{
399 unuse_pde(p);
400}
401
Al Viro6b255392015-11-17 10:20:54 -0500402static const char *proc_get_link(struct dentry *dentry,
Al Virofceef392015-12-29 15:58:39 -0500403 struct inode *inode,
404 struct delayed_call *done)
Al Viro7e0e9532015-02-21 22:16:11 -0500405{
Al Viro6b255392015-11-17 10:20:54 -0500406 struct proc_dir_entry *pde = PDE(inode);
Al Viro7e0e9532015-02-21 22:16:11 -0500407 if (unlikely(!use_pde(pde)))
408 return ERR_PTR(-EINVAL);
Al Virofceef392015-12-29 15:58:39 -0500409 set_delayed_call(done, proc_put_link, pde);
Al Viro680baac2015-05-02 13:32:22 -0400410 return pde->data;
Al Viro7e0e9532015-02-21 22:16:11 -0500411}
412
Al Viro7e0e9532015-02-21 22:16:11 -0500413const struct inode_operations proc_link_inode_operations = {
414 .readlink = generic_readlink,
Al Viro6b255392015-11-17 10:20:54 -0500415 .get_link = proc_get_link,
Al Viro7e0e9532015-02-21 22:16:11 -0500416};
417
Alexey Dobriyan6d1b6e42011-01-12 17:00:33 -0800418struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419{
Linus Torvalds51f08852013-03-22 11:44:04 -0700420 struct inode *inode = new_inode_pseudo(sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421
Linus Torvalds51f08852013-03-22 11:44:04 -0700422 if (inode) {
423 inode->i_ino = de->low_ino;
David Howellsa1d4aeb2008-02-07 00:15:45 -0800424 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
David Howellsa1d4aeb2008-02-07 00:15:45 -0800425 PROC_I(inode)->pde = de;
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700426
Eric W. Biedermaneb6d38d2015-05-11 16:44:25 -0500427 if (is_empty_pde(de)) {
428 make_empty_dir_inode(inode);
429 return inode;
430 }
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700431 if (de->mode) {
432 inode->i_mode = de->mode;
433 inode->i_uid = de->uid;
434 inode->i_gid = de->gid;
435 }
436 if (de->size)
437 inode->i_size = de->size;
438 if (de->nlink)
Miklos Szeredibfe86842011-10-28 14:13:29 +0200439 set_nlink(inode, de->nlink);
Al Virob6cdc732013-03-30 21:20:14 -0400440 WARN_ON(!de->proc_iops);
441 inode->i_op = de->proc_iops;
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700442 if (de->proc_fops) {
443 if (S_ISREG(inode->i_mode)) {
David Howellsa1d4aeb2008-02-07 00:15:45 -0800444#ifdef CONFIG_COMPAT
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700445 if (!de->proc_fops->compat_ioctl)
446 inode->i_fop =
447 &proc_reg_file_ops_no_compat;
448 else
David Howellsa1d4aeb2008-02-07 00:15:45 -0800449#endif
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700450 inode->i_fop = &proc_reg_file_ops;
451 } else {
452 inode->i_fop = de->proc_fops;
David Howellsa1d4aeb2008-02-07 00:15:45 -0800453 }
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700454 }
Alexey Dobriyan99b76232009-03-25 22:48:06 +0300455 } else
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800456 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 return inode;
Al Virod3d009c2013-01-25 20:11:22 -0500458}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
Eric W. Biedermane94591d2016-06-09 15:32:10 -0500460int proc_fill_super(struct super_block *s, void *data, int silent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461{
Eric W. Biedermane94591d2016-06-09 15:32:10 -0500462 struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
Maxim Patlasov87e0aab2013-02-20 13:13:32 +1100463 struct inode *root_inode;
Eric W. Biederman00978752014-07-31 03:10:50 -0700464 int ret;
Maxim Patlasov87e0aab2013-02-20 13:13:32 +1100465
Eric W. Biedermane94591d2016-06-09 15:32:10 -0500466 if (!proc_parse_options(data, ns))
467 return -EINVAL;
468
Eric W. Biedermana2982cc2016-06-09 15:34:02 -0500469 /* User space would break if executables or devices appear on proc */
470 s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
Linus Torvalds92d03282006-07-15 12:20:05 -0700471 s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 s->s_blocksize = 1024;
473 s->s_blocksize_bits = 10;
474 s->s_magic = PROC_SUPER_MAGIC;
475 s->s_op = &proc_sops;
476 s->s_time_gran = 1;
Linus Torvaldsa867d732016-07-29 15:54:19 -0700477
478 /*
479 * procfs isn't actually a stacking filesystem; however, there is
480 * too much magic going on inside it to permit stacking things on
481 * top of it
482 */
483 s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800485 pde_get(&proc_root);
Maxim Patlasov87e0aab2013-02-20 13:13:32 +1100486 root_inode = proc_get_inode(s, &proc_root);
487 if (!root_inode) {
Andrew Morton87ebdc02013-02-27 17:03:16 -0800488 pr_err("proc_fill_super: get root inode failed\n");
Maxim Patlasov87e0aab2013-02-20 13:13:32 +1100489 return -ENOMEM;
490 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491
Maxim Patlasov87e0aab2013-02-20 13:13:32 +1100492 s->s_root = d_make_root(root_inode);
493 if (!s->s_root) {
Andrew Morton87ebdc02013-02-27 17:03:16 -0800494 pr_err("proc_fill_super: allocate dentry failed\n");
Maxim Patlasov87e0aab2013-02-20 13:13:32 +1100495 return -ENOMEM;
496 }
497
Eric W. Biederman00978752014-07-31 03:10:50 -0700498 ret = proc_setup_self(s);
499 if (ret) {
500 return ret;
501 }
502 return proc_setup_thread_self(s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503}