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1/*
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>
10#include <linux/pid_namespace.h>
11#include <linux/mm.h>
12#include <linux/string.h>
13#include <linux/stat.h>
14#include <linux/completion.h>
15#include <linux/poll.h>
16#include <linux/printk.h>
17#include <linux/file.h>
18#include <linux/limits.h>
19#include <linux/init.h>
20#include <linux/module.h>
21#include <linux/sysctl.h>
22#include <linux/seq_file.h>
23#include <linux/slab.h>
24#include <linux/mount.h>
25#include <linux/magic.h>
26
27#include <asm/uaccess.h>
28
29#include "internal.h"
30
31static void proc_evict_inode(struct inode *inode)
32{
33 struct proc_dir_entry *de;
34 struct ctl_table_header *head;
35
36 truncate_inode_pages_final(&inode->i_data);
37 clear_inode(inode);
38
39 /* Stop tracking associated processes */
40 put_pid(PROC_I(inode)->pid);
41
42 /* Let go of any associated proc directory entry */
43 de = PDE(inode);
44 if (de)
45 pde_put(de);
46 head = PROC_I(inode)->sysctl;
47 if (head) {
48 RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
49 sysctl_head_put(head);
50 }
51}
52
53static struct kmem_cache * proc_inode_cachep;
54
55static struct inode *proc_alloc_inode(struct super_block *sb)
56{
57 struct proc_inode *ei;
58 struct inode *inode;
59
60 ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
61 if (!ei)
62 return NULL;
63 ei->pid = NULL;
64 ei->fd = 0;
65 ei->op.proc_get_link = NULL;
66 ei->pde = NULL;
67 ei->sysctl = NULL;
68 ei->sysctl_entry = NULL;
69 ei->ns_ops = NULL;
70 inode = &ei->vfs_inode;
71 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
72 return inode;
73}
74
75static void proc_i_callback(struct rcu_head *head)
76{
77 struct inode *inode = container_of(head, struct inode, i_rcu);
78 kmem_cache_free(proc_inode_cachep, PROC_I(inode));
79}
80
81static void proc_destroy_inode(struct inode *inode)
82{
83 call_rcu(&inode->i_rcu, proc_i_callback);
84}
85
86static void init_once(void *foo)
87{
88 struct proc_inode *ei = (struct proc_inode *) foo;
89
90 inode_init_once(&ei->vfs_inode);
91}
92
93void __init proc_init_inodecache(void)
94{
95 proc_inode_cachep = kmem_cache_create("proc_inode_cache",
96 sizeof(struct proc_inode),
97 0, (SLAB_RECLAIM_ACCOUNT|
98 SLAB_MEM_SPREAD|SLAB_ACCOUNT|
99 SLAB_PANIC),
100 init_once);
101}
102
103static int proc_show_options(struct seq_file *seq, struct dentry *root)
104{
105 struct super_block *sb = root->d_sb;
106 struct pid_namespace *pid = sb->s_fs_info;
107
108 if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
109 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
110 if (pid->hide_pid != 0)
111 seq_printf(seq, ",hidepid=%u", pid->hide_pid);
112
113 return 0;
114}
115
116static const struct super_operations proc_sops = {
117 .alloc_inode = proc_alloc_inode,
118 .destroy_inode = proc_destroy_inode,
119 .drop_inode = generic_delete_inode,
120 .evict_inode = proc_evict_inode,
121 .statfs = simple_statfs,
122 .remount_fs = proc_remount,
123 .show_options = proc_show_options,
124};
125
126enum {BIAS = -1U<<31};
127
128static inline int use_pde(struct proc_dir_entry *pde)
129{
130 return atomic_inc_unless_negative(&pde->in_use);
131}
132
133static void unuse_pde(struct proc_dir_entry *pde)
134{
135 if (atomic_dec_return(&pde->in_use) == BIAS)
136 complete(pde->pde_unload_completion);
137}
138
139/* pde is locked */
140static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
141{
142 if (pdeo->closing) {
143 /* somebody else is doing that, just wait */
144 DECLARE_COMPLETION_ONSTACK(c);
145 pdeo->c = &c;
146 spin_unlock(&pde->pde_unload_lock);
147 wait_for_completion(&c);
148 spin_lock(&pde->pde_unload_lock);
149 } else {
150 struct file *file;
151 pdeo->closing = 1;
152 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);
157 if (pdeo->c)
158 complete(pdeo->c);
159 kfree(pdeo);
160 }
161}
162
163void proc_entry_rundown(struct proc_dir_entry *de)
164{
165 DECLARE_COMPLETION_ONSTACK(c);
166 /* Wait until all existing callers into module are done. */
167 de->pde_unload_completion = &c;
168 if (atomic_add_return(BIAS, &de->in_use) != BIAS)
169 wait_for_completion(&c);
170
171 spin_lock(&de->pde_unload_lock);
172 while (!list_empty(&de->pde_openers)) {
173 struct pde_opener *pdeo;
174 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
175 close_pdeo(de, pdeo);
176 }
177 spin_unlock(&de->pde_unload_lock);
178}
179
180static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
181{
182 struct proc_dir_entry *pde = PDE(file_inode(file));
183 loff_t rv = -EINVAL;
184 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);
191 }
192 return rv;
193}
194
195static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
196{
197 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
198 struct proc_dir_entry *pde = PDE(file_inode(file));
199 ssize_t rv = -EIO;
200 if (use_pde(pde)) {
201 read = pde->proc_fops->read;
202 if (read)
203 rv = read(file, buf, count, ppos);
204 unuse_pde(pde);
205 }
206 return rv;
207}
208
209static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
210{
211 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
212 struct proc_dir_entry *pde = PDE(file_inode(file));
213 ssize_t rv = -EIO;
214 if (use_pde(pde)) {
215 write = pde->proc_fops->write;
216 if (write)
217 rv = write(file, buf, count, ppos);
218 unuse_pde(pde);
219 }
220 return rv;
221}
222
223static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
224{
225 struct proc_dir_entry *pde = PDE(file_inode(file));
226 unsigned int rv = DEFAULT_POLLMASK;
227 unsigned int (*poll)(struct file *, struct poll_table_struct *);
228 if (use_pde(pde)) {
229 poll = pde->proc_fops->poll;
230 if (poll)
231 rv = poll(file, pts);
232 unuse_pde(pde);
233 }
234 return rv;
235}
236
237static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
238{
239 struct proc_dir_entry *pde = PDE(file_inode(file));
240 long rv = -ENOTTY;
241 long (*ioctl)(struct file *, unsigned int, unsigned long);
242 if (use_pde(pde)) {
243 ioctl = pde->proc_fops->unlocked_ioctl;
244 if (ioctl)
245 rv = ioctl(file, cmd, arg);
246 unuse_pde(pde);
247 }
248 return rv;
249}
250
251#ifdef CONFIG_COMPAT
252static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
253{
254 struct proc_dir_entry *pde = PDE(file_inode(file));
255 long rv = -ENOTTY;
256 long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
257 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);
262 }
263 return rv;
264}
265#endif
266
267static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
268{
269 struct proc_dir_entry *pde = PDE(file_inode(file));
270 int rv = -EIO;
271 int (*mmap)(struct file *, struct vm_area_struct *);
272 if (use_pde(pde)) {
273 mmap = pde->proc_fops->mmap;
274 if (mmap)
275 rv = mmap(file, vma);
276 unuse_pde(pde);
277 }
278 return rv;
279}
280
281static 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)
285{
286 struct proc_dir_entry *pde = PDE(file_inode(file));
287 unsigned long rv = -EIO;
288
289 if (use_pde(pde)) {
290 typeof(proc_reg_get_unmapped_area) *get_area;
291
292 get_area = pde->proc_fops->get_unmapped_area;
293#ifdef CONFIG_MMU
294 if (!get_area)
295 get_area = current->mm->get_unmapped_area;
296#endif
297
298 if (get_area)
299 rv = get_area(file, orig_addr, len, pgoff, flags);
300 else
301 rv = orig_addr;
302 unuse_pde(pde);
303 }
304 return rv;
305}
306
307static 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 *);
312 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 */
325 pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL);
326 if (!pdeo)
327 return -ENOMEM;
328
329 if (!use_pde(pde)) {
330 kfree(pdeo);
331 return -ENOENT;
332 }
333 open = pde->proc_fops->open;
334 release = pde->proc_fops->release;
335
336 if (open)
337 rv = open(inode, file);
338
339 if (rv == 0 && release) {
340 /* To know what to release. */
341 pdeo->file = file;
342 /* Strictly for "too late" ->release in proc_reg_release(). */
343 spin_lock(&pde->pde_unload_lock);
344 list_add(&pdeo->lh, &pde->pde_openers);
345 spin_unlock(&pde->pde_unload_lock);
346 } else
347 kfree(pdeo);
348
349 unuse_pde(pde);
350 return rv;
351}
352
353static int proc_reg_release(struct inode *inode, struct file *file)
354{
355 struct proc_dir_entry *pde = PDE(inode);
356 struct pde_opener *pdeo;
357 spin_lock(&pde->pde_unload_lock);
358 list_for_each_entry(pdeo, &pde->pde_openers, lh) {
359 if (pdeo->file == file) {
360 close_pdeo(pde, pdeo);
361 break;
362 }
363 }
364 spin_unlock(&pde->pde_unload_lock);
365 return 0;
366}
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,
378 .get_unmapped_area = proc_reg_get_unmapped_area,
379 .open = proc_reg_open,
380 .release = proc_reg_release,
381};
382
383#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,
391 .get_unmapped_area = proc_reg_get_unmapped_area,
392 .open = proc_reg_open,
393 .release = proc_reg_release,
394};
395#endif
396
397static void proc_put_link(void *p)
398{
399 unuse_pde(p);
400}
401
402static const char *proc_get_link(struct dentry *dentry,
403 struct inode *inode,
404 struct delayed_call *done)
405{
406 struct proc_dir_entry *pde = PDE(inode);
407 if (unlikely(!use_pde(pde)))
408 return ERR_PTR(-EINVAL);
409 set_delayed_call(done, proc_put_link, pde);
410 return pde->data;
411}
412
413const struct inode_operations proc_link_inode_operations = {
414 .readlink = generic_readlink,
415 .get_link = proc_get_link,
416};
417
418struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
419{
420 struct inode *inode = new_inode_pseudo(sb);
421
422 if (inode) {
423 inode->i_ino = de->low_ino;
424 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
425 PROC_I(inode)->pde = de;
426
427 if (is_empty_pde(de)) {
428 make_empty_dir_inode(inode);
429 return inode;
430 }
431 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)
439 set_nlink(inode, de->nlink);
440 WARN_ON(!de->proc_iops);
441 inode->i_op = de->proc_iops;
442 if (de->proc_fops) {
443 if (S_ISREG(inode->i_mode)) {
444#ifdef CONFIG_COMPAT
445 if (!de->proc_fops->compat_ioctl)
446 inode->i_fop =
447 &proc_reg_file_ops_no_compat;
448 else
449#endif
450 inode->i_fop = &proc_reg_file_ops;
451 } else {
452 inode->i_fop = de->proc_fops;
453 }
454 }
455 } else
456 pde_put(de);
457 return inode;
458}
459
460int proc_fill_super(struct super_block *s)
461{
462 struct inode *root_inode;
463 int ret;
464
465 s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
466 s->s_blocksize = 1024;
467 s->s_blocksize_bits = 10;
468 s->s_magic = PROC_SUPER_MAGIC;
469 s->s_op = &proc_sops;
470 s->s_time_gran = 1;
471
472 pde_get(&proc_root);
473 root_inode = proc_get_inode(s, &proc_root);
474 if (!root_inode) {
475 pr_err("proc_fill_super: get root inode failed\n");
476 return -ENOMEM;
477 }
478
479 s->s_root = d_make_root(root_inode);
480 if (!s->s_root) {
481 pr_err("proc_fill_super: allocate dentry failed\n");
482 return -ENOMEM;
483 }
484
485 ret = proc_setup_self(s);
486 if (ret) {
487 return ret;
488 }
489 return proc_setup_thread_self(s);
490}
1/*
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>
10#include <linux/pid_namespace.h>
11#include <linux/mm.h>
12#include <linux/string.h>
13#include <linux/stat.h>
14#include <linux/completion.h>
15#include <linux/poll.h>
16#include <linux/printk.h>
17#include <linux/file.h>
18#include <linux/limits.h>
19#include <linux/init.h>
20#include <linux/module.h>
21#include <linux/sysctl.h>
22#include <linux/seq_file.h>
23#include <linux/slab.h>
24#include <linux/mount.h>
25#include <linux/magic.h>
26
27#include <asm/uaccess.h>
28
29#include "internal.h"
30
31static void proc_evict_inode(struct inode *inode)
32{
33 struct proc_dir_entry *de;
34 struct ctl_table_header *head;
35 const struct proc_ns_operations *ns_ops;
36 void *ns;
37
38 truncate_inode_pages_final(&inode->i_data);
39 clear_inode(inode);
40
41 /* Stop tracking associated processes */
42 put_pid(PROC_I(inode)->pid);
43
44 /* Let go of any associated proc directory entry */
45 de = PROC_I(inode)->pde;
46 if (de)
47 pde_put(de);
48 head = PROC_I(inode)->sysctl;
49 if (head) {
50 RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
51 sysctl_head_put(head);
52 }
53 /* Release any associated namespace */
54 ns_ops = PROC_I(inode)->ns.ns_ops;
55 ns = PROC_I(inode)->ns.ns;
56 if (ns_ops && ns)
57 ns_ops->put(ns);
58}
59
60static struct kmem_cache * proc_inode_cachep;
61
62static struct inode *proc_alloc_inode(struct super_block *sb)
63{
64 struct proc_inode *ei;
65 struct inode *inode;
66
67 ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
68 if (!ei)
69 return NULL;
70 ei->pid = NULL;
71 ei->fd = 0;
72 ei->op.proc_get_link = NULL;
73 ei->pde = NULL;
74 ei->sysctl = NULL;
75 ei->sysctl_entry = NULL;
76 ei->ns.ns = NULL;
77 ei->ns.ns_ops = NULL;
78 inode = &ei->vfs_inode;
79 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
80 return inode;
81}
82
83static void proc_i_callback(struct rcu_head *head)
84{
85 struct inode *inode = container_of(head, struct inode, i_rcu);
86 kmem_cache_free(proc_inode_cachep, PROC_I(inode));
87}
88
89static void proc_destroy_inode(struct inode *inode)
90{
91 call_rcu(&inode->i_rcu, proc_i_callback);
92}
93
94static void init_once(void *foo)
95{
96 struct proc_inode *ei = (struct proc_inode *) foo;
97
98 inode_init_once(&ei->vfs_inode);
99}
100
101void __init proc_init_inodecache(void)
102{
103 proc_inode_cachep = kmem_cache_create("proc_inode_cache",
104 sizeof(struct proc_inode),
105 0, (SLAB_RECLAIM_ACCOUNT|
106 SLAB_MEM_SPREAD|SLAB_PANIC),
107 init_once);
108}
109
110static int proc_show_options(struct seq_file *seq, struct dentry *root)
111{
112 struct super_block *sb = root->d_sb;
113 struct pid_namespace *pid = sb->s_fs_info;
114
115 if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
116 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
117 if (pid->hide_pid != 0)
118 seq_printf(seq, ",hidepid=%u", pid->hide_pid);
119
120 return 0;
121}
122
123static const struct super_operations proc_sops = {
124 .alloc_inode = proc_alloc_inode,
125 .destroy_inode = proc_destroy_inode,
126 .drop_inode = generic_delete_inode,
127 .evict_inode = proc_evict_inode,
128 .statfs = simple_statfs,
129 .remount_fs = proc_remount,
130 .show_options = proc_show_options,
131};
132
133enum {BIAS = -1U<<31};
134
135static inline int use_pde(struct proc_dir_entry *pde)
136{
137 return atomic_inc_unless_negative(&pde->in_use);
138}
139
140static void unuse_pde(struct proc_dir_entry *pde)
141{
142 if (atomic_dec_return(&pde->in_use) == BIAS)
143 complete(pde->pde_unload_completion);
144}
145
146/* pde is locked */
147static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
148{
149 if (pdeo->closing) {
150 /* somebody else is doing that, just wait */
151 DECLARE_COMPLETION_ONSTACK(c);
152 pdeo->c = &c;
153 spin_unlock(&pde->pde_unload_lock);
154 wait_for_completion(&c);
155 spin_lock(&pde->pde_unload_lock);
156 } else {
157 struct file *file;
158 pdeo->closing = 1;
159 spin_unlock(&pde->pde_unload_lock);
160 file = pdeo->file;
161 pde->proc_fops->release(file_inode(file), file);
162 spin_lock(&pde->pde_unload_lock);
163 list_del_init(&pdeo->lh);
164 if (pdeo->c)
165 complete(pdeo->c);
166 kfree(pdeo);
167 }
168}
169
170void proc_entry_rundown(struct proc_dir_entry *de)
171{
172 DECLARE_COMPLETION_ONSTACK(c);
173 /* Wait until all existing callers into module are done. */
174 de->pde_unload_completion = &c;
175 if (atomic_add_return(BIAS, &de->in_use) != BIAS)
176 wait_for_completion(&c);
177
178 spin_lock(&de->pde_unload_lock);
179 while (!list_empty(&de->pde_openers)) {
180 struct pde_opener *pdeo;
181 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
182 close_pdeo(de, pdeo);
183 }
184 spin_unlock(&de->pde_unload_lock);
185}
186
187static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
188{
189 struct proc_dir_entry *pde = PDE(file_inode(file));
190 loff_t rv = -EINVAL;
191 if (use_pde(pde)) {
192 loff_t (*llseek)(struct file *, loff_t, int);
193 llseek = pde->proc_fops->llseek;
194 if (!llseek)
195 llseek = default_llseek;
196 rv = llseek(file, offset, whence);
197 unuse_pde(pde);
198 }
199 return rv;
200}
201
202static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
203{
204 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
205 struct proc_dir_entry *pde = PDE(file_inode(file));
206 ssize_t rv = -EIO;
207 if (use_pde(pde)) {
208 read = pde->proc_fops->read;
209 if (read)
210 rv = read(file, buf, count, ppos);
211 unuse_pde(pde);
212 }
213 return rv;
214}
215
216static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
217{
218 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
219 struct proc_dir_entry *pde = PDE(file_inode(file));
220 ssize_t rv = -EIO;
221 if (use_pde(pde)) {
222 write = pde->proc_fops->write;
223 if (write)
224 rv = write(file, buf, count, ppos);
225 unuse_pde(pde);
226 }
227 return rv;
228}
229
230static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts)
231{
232 struct proc_dir_entry *pde = PDE(file_inode(file));
233 unsigned int rv = DEFAULT_POLLMASK;
234 unsigned int (*poll)(struct file *, struct poll_table_struct *);
235 if (use_pde(pde)) {
236 poll = pde->proc_fops->poll;
237 if (poll)
238 rv = poll(file, pts);
239 unuse_pde(pde);
240 }
241 return rv;
242}
243
244static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
245{
246 struct proc_dir_entry *pde = PDE(file_inode(file));
247 long rv = -ENOTTY;
248 long (*ioctl)(struct file *, unsigned int, unsigned long);
249 if (use_pde(pde)) {
250 ioctl = pde->proc_fops->unlocked_ioctl;
251 if (ioctl)
252 rv = ioctl(file, cmd, arg);
253 unuse_pde(pde);
254 }
255 return rv;
256}
257
258#ifdef CONFIG_COMPAT
259static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
260{
261 struct proc_dir_entry *pde = PDE(file_inode(file));
262 long rv = -ENOTTY;
263 long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
264 if (use_pde(pde)) {
265 compat_ioctl = pde->proc_fops->compat_ioctl;
266 if (compat_ioctl)
267 rv = compat_ioctl(file, cmd, arg);
268 unuse_pde(pde);
269 }
270 return rv;
271}
272#endif
273
274static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
275{
276 struct proc_dir_entry *pde = PDE(file_inode(file));
277 int rv = -EIO;
278 int (*mmap)(struct file *, struct vm_area_struct *);
279 if (use_pde(pde)) {
280 mmap = pde->proc_fops->mmap;
281 if (mmap)
282 rv = mmap(file, vma);
283 unuse_pde(pde);
284 }
285 return rv;
286}
287
288static unsigned long
289proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr,
290 unsigned long len, unsigned long pgoff,
291 unsigned long flags)
292{
293 struct proc_dir_entry *pde = PDE(file_inode(file));
294 unsigned long rv = -EIO;
295
296 if (use_pde(pde)) {
297 typeof(proc_reg_get_unmapped_area) *get_area;
298
299 get_area = pde->proc_fops->get_unmapped_area;
300#ifdef CONFIG_MMU
301 if (!get_area)
302 get_area = current->mm->get_unmapped_area;
303#endif
304
305 if (get_area)
306 rv = get_area(file, orig_addr, len, pgoff, flags);
307 else
308 rv = orig_addr;
309 unuse_pde(pde);
310 }
311 return rv;
312}
313
314static int proc_reg_open(struct inode *inode, struct file *file)
315{
316 struct proc_dir_entry *pde = PDE(inode);
317 int rv = 0;
318 int (*open)(struct inode *, struct file *);
319 int (*release)(struct inode *, struct file *);
320 struct pde_opener *pdeo;
321
322 /*
323 * What for, you ask? Well, we can have open, rmmod, remove_proc_entry
324 * sequence. ->release won't be called because ->proc_fops will be
325 * cleared. Depending on complexity of ->release, consequences vary.
326 *
327 * We can't wait for mercy when close will be done for real, it's
328 * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release
329 * by hand in remove_proc_entry(). For this, save opener's credentials
330 * for later.
331 */
332 pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL);
333 if (!pdeo)
334 return -ENOMEM;
335
336 if (!use_pde(pde)) {
337 kfree(pdeo);
338 return -ENOENT;
339 }
340 open = pde->proc_fops->open;
341 release = pde->proc_fops->release;
342
343 if (open)
344 rv = open(inode, file);
345
346 if (rv == 0 && release) {
347 /* To know what to release. */
348 pdeo->file = file;
349 /* Strictly for "too late" ->release in proc_reg_release(). */
350 spin_lock(&pde->pde_unload_lock);
351 list_add(&pdeo->lh, &pde->pde_openers);
352 spin_unlock(&pde->pde_unload_lock);
353 } else
354 kfree(pdeo);
355
356 unuse_pde(pde);
357 return rv;
358}
359
360static int proc_reg_release(struct inode *inode, struct file *file)
361{
362 struct proc_dir_entry *pde = PDE(inode);
363 struct pde_opener *pdeo;
364 spin_lock(&pde->pde_unload_lock);
365 list_for_each_entry(pdeo, &pde->pde_openers, lh) {
366 if (pdeo->file == file) {
367 close_pdeo(pde, pdeo);
368 break;
369 }
370 }
371 spin_unlock(&pde->pde_unload_lock);
372 return 0;
373}
374
375static const struct file_operations proc_reg_file_ops = {
376 .llseek = proc_reg_llseek,
377 .read = proc_reg_read,
378 .write = proc_reg_write,
379 .poll = proc_reg_poll,
380 .unlocked_ioctl = proc_reg_unlocked_ioctl,
381#ifdef CONFIG_COMPAT
382 .compat_ioctl = proc_reg_compat_ioctl,
383#endif
384 .mmap = proc_reg_mmap,
385 .get_unmapped_area = proc_reg_get_unmapped_area,
386 .open = proc_reg_open,
387 .release = proc_reg_release,
388};
389
390#ifdef CONFIG_COMPAT
391static const struct file_operations proc_reg_file_ops_no_compat = {
392 .llseek = proc_reg_llseek,
393 .read = proc_reg_read,
394 .write = proc_reg_write,
395 .poll = proc_reg_poll,
396 .unlocked_ioctl = proc_reg_unlocked_ioctl,
397 .mmap = proc_reg_mmap,
398 .get_unmapped_area = proc_reg_get_unmapped_area,
399 .open = proc_reg_open,
400 .release = proc_reg_release,
401};
402#endif
403
404struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
405{
406 struct inode *inode = new_inode_pseudo(sb);
407
408 if (inode) {
409 inode->i_ino = de->low_ino;
410 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
411 PROC_I(inode)->pde = de;
412
413 if (de->mode) {
414 inode->i_mode = de->mode;
415 inode->i_uid = de->uid;
416 inode->i_gid = de->gid;
417 }
418 if (de->size)
419 inode->i_size = de->size;
420 if (de->nlink)
421 set_nlink(inode, de->nlink);
422 WARN_ON(!de->proc_iops);
423 inode->i_op = de->proc_iops;
424 if (de->proc_fops) {
425 if (S_ISREG(inode->i_mode)) {
426#ifdef CONFIG_COMPAT
427 if (!de->proc_fops->compat_ioctl)
428 inode->i_fop =
429 &proc_reg_file_ops_no_compat;
430 else
431#endif
432 inode->i_fop = &proc_reg_file_ops;
433 } else {
434 inode->i_fop = de->proc_fops;
435 }
436 }
437 } else
438 pde_put(de);
439 return inode;
440}
441
442int proc_fill_super(struct super_block *s)
443{
444 struct inode *root_inode;
445
446 s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC;
447 s->s_blocksize = 1024;
448 s->s_blocksize_bits = 10;
449 s->s_magic = PROC_SUPER_MAGIC;
450 s->s_op = &proc_sops;
451 s->s_time_gran = 1;
452
453 pde_get(&proc_root);
454 root_inode = proc_get_inode(s, &proc_root);
455 if (!root_inode) {
456 pr_err("proc_fill_super: get root inode failed\n");
457 return -ENOMEM;
458 }
459
460 s->s_root = d_make_root(root_inode);
461 if (!s->s_root) {
462 pr_err("proc_fill_super: allocate dentry failed\n");
463 return -ENOMEM;
464 }
465
466 return proc_setup_self(s);
467}