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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/proc/inode.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/cache.h>
9#include <linux/time.h>
10#include <linux/proc_fs.h>
11#include <linux/kernel.h>
12#include <linux/pid_namespace.h>
13#include <linux/mm.h>
14#include <linux/string.h>
15#include <linux/stat.h>
16#include <linux/completion.h>
17#include <linux/poll.h>
18#include <linux/printk.h>
19#include <linux/file.h>
20#include <linux/limits.h>
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/sysctl.h>
24#include <linux/seq_file.h>
25#include <linux/slab.h>
26#include <linux/mount.h>
27#include <linux/magic.h>
28
29#include <linux/uaccess.h>
30
31#include "internal.h"
32
33static void proc_evict_inode(struct inode *inode)
34{
35 struct proc_dir_entry *de;
36 struct ctl_table_header *head;
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 = PDE(inode);
46 if (de)
47 pde_put(de);
48
49 head = PROC_I(inode)->sysctl;
50 if (head) {
51 RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
52 proc_sys_evict_inode(inode, head);
53 }
54}
55
56static struct kmem_cache *proc_inode_cachep __ro_after_init;
57static struct kmem_cache *pde_opener_cache __ro_after_init;
58
59static struct inode *proc_alloc_inode(struct super_block *sb)
60{
61 struct proc_inode *ei;
62 struct inode *inode;
63
64 ei = kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
65 if (!ei)
66 return NULL;
67 ei->pid = NULL;
68 ei->fd = 0;
69 ei->op.proc_get_link = NULL;
70 ei->pde = NULL;
71 ei->sysctl = NULL;
72 ei->sysctl_entry = NULL;
73 ei->ns_ops = NULL;
74 inode = &ei->vfs_inode;
75 return inode;
76}
77
78static void proc_i_callback(struct rcu_head *head)
79{
80 struct inode *inode = container_of(head, struct inode, i_rcu);
81 kmem_cache_free(proc_inode_cachep, PROC_I(inode));
82}
83
84static void proc_destroy_inode(struct inode *inode)
85{
86 call_rcu(&inode->i_rcu, proc_i_callback);
87}
88
89static void init_once(void *foo)
90{
91 struct proc_inode *ei = (struct proc_inode *) foo;
92
93 inode_init_once(&ei->vfs_inode);
94}
95
96void __init proc_init_kmemcache(void)
97{
98 proc_inode_cachep = kmem_cache_create("proc_inode_cache",
99 sizeof(struct proc_inode),
100 0, (SLAB_RECLAIM_ACCOUNT|
101 SLAB_MEM_SPREAD|SLAB_ACCOUNT|
102 SLAB_PANIC),
103 init_once);
104 pde_opener_cache =
105 kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0,
106 SLAB_ACCOUNT|SLAB_PANIC, NULL);
107 proc_dir_entry_cache = kmem_cache_create_usercopy(
108 "proc_dir_entry", sizeof(struct proc_dir_entry), 0, SLAB_PANIC,
109 offsetof(struct proc_dir_entry, inline_name),
110 sizeof_field(struct proc_dir_entry, inline_name), NULL);
111}
112
113static int proc_show_options(struct seq_file *seq, struct dentry *root)
114{
115 struct super_block *sb = root->d_sb;
116 struct pid_namespace *pid = sb->s_fs_info;
117
118 if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
119 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
120 if (pid->hide_pid != HIDEPID_OFF)
121 seq_printf(seq, ",hidepid=%u", pid->hide_pid);
122
123 return 0;
124}
125
126static const struct super_operations proc_sops = {
127 .alloc_inode = proc_alloc_inode,
128 .destroy_inode = proc_destroy_inode,
129 .drop_inode = generic_delete_inode,
130 .evict_inode = proc_evict_inode,
131 .statfs = simple_statfs,
132 .remount_fs = proc_remount,
133 .show_options = proc_show_options,
134};
135
136enum {BIAS = -1U<<31};
137
138static inline int use_pde(struct proc_dir_entry *pde)
139{
140 return likely(atomic_inc_unless_negative(&pde->in_use));
141}
142
143static void unuse_pde(struct proc_dir_entry *pde)
144{
145 if (unlikely(atomic_dec_return(&pde->in_use) == BIAS))
146 complete(pde->pde_unload_completion);
147}
148
149/* pde is locked on entry, unlocked on exit */
150static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
151{
152 /*
153 * close() (proc_reg_release()) can't delete an entry and proceed:
154 * ->release hook needs to be available at the right moment.
155 *
156 * rmmod (remove_proc_entry() et al) can't delete an entry and proceed:
157 * "struct file" needs to be available at the right moment.
158 *
159 * Therefore, first process to enter this function does ->release() and
160 * signals its completion to the other process which does nothing.
161 */
162 if (pdeo->closing) {
163 /* somebody else is doing that, just wait */
164 DECLARE_COMPLETION_ONSTACK(c);
165 pdeo->c = &c;
166 spin_unlock(&pde->pde_unload_lock);
167 wait_for_completion(&c);
168 } else {
169 struct file *file;
170 struct completion *c;
171
172 pdeo->closing = true;
173 spin_unlock(&pde->pde_unload_lock);
174 file = pdeo->file;
175 pde->proc_fops->release(file_inode(file), file);
176 spin_lock(&pde->pde_unload_lock);
177 /* After ->release. */
178 list_del(&pdeo->lh);
179 c = pdeo->c;
180 spin_unlock(&pde->pde_unload_lock);
181 if (unlikely(c))
182 complete(c);
183 kmem_cache_free(pde_opener_cache, pdeo);
184 }
185}
186
187void proc_entry_rundown(struct proc_dir_entry *de)
188{
189 DECLARE_COMPLETION_ONSTACK(c);
190 /* Wait until all existing callers into module are done. */
191 de->pde_unload_completion = &c;
192 if (atomic_add_return(BIAS, &de->in_use) != BIAS)
193 wait_for_completion(&c);
194
195 /* ->pde_openers list can't grow from now on. */
196
197 spin_lock(&de->pde_unload_lock);
198 while (!list_empty(&de->pde_openers)) {
199 struct pde_opener *pdeo;
200 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
201 close_pdeo(de, pdeo);
202 spin_lock(&de->pde_unload_lock);
203 }
204 spin_unlock(&de->pde_unload_lock);
205}
206
207static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
208{
209 struct proc_dir_entry *pde = PDE(file_inode(file));
210 loff_t rv = -EINVAL;
211 if (use_pde(pde)) {
212 loff_t (*llseek)(struct file *, loff_t, int);
213 llseek = pde->proc_fops->llseek;
214 if (!llseek)
215 llseek = default_llseek;
216 rv = llseek(file, offset, whence);
217 unuse_pde(pde);
218 }
219 return rv;
220}
221
222static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
223{
224 ssize_t (*read)(struct file *, char __user *, size_t, loff_t *);
225 struct proc_dir_entry *pde = PDE(file_inode(file));
226 ssize_t rv = -EIO;
227 if (use_pde(pde)) {
228 read = pde->proc_fops->read;
229 if (read)
230 rv = read(file, buf, count, ppos);
231 unuse_pde(pde);
232 }
233 return rv;
234}
235
236static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
237{
238 ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *);
239 struct proc_dir_entry *pde = PDE(file_inode(file));
240 ssize_t rv = -EIO;
241 if (use_pde(pde)) {
242 write = pde->proc_fops->write;
243 if (write)
244 rv = write(file, buf, count, ppos);
245 unuse_pde(pde);
246 }
247 return rv;
248}
249
250static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts)
251{
252 struct proc_dir_entry *pde = PDE(file_inode(file));
253 __poll_t rv = DEFAULT_POLLMASK;
254 __poll_t (*poll)(struct file *, struct poll_table_struct *);
255 if (use_pde(pde)) {
256 poll = pde->proc_fops->poll;
257 if (poll)
258 rv = poll(file, pts);
259 unuse_pde(pde);
260 }
261 return rv;
262}
263
264static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
265{
266 struct proc_dir_entry *pde = PDE(file_inode(file));
267 long rv = -ENOTTY;
268 long (*ioctl)(struct file *, unsigned int, unsigned long);
269 if (use_pde(pde)) {
270 ioctl = pde->proc_fops->unlocked_ioctl;
271 if (ioctl)
272 rv = ioctl(file, cmd, arg);
273 unuse_pde(pde);
274 }
275 return rv;
276}
277
278#ifdef CONFIG_COMPAT
279static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
280{
281 struct proc_dir_entry *pde = PDE(file_inode(file));
282 long rv = -ENOTTY;
283 long (*compat_ioctl)(struct file *, unsigned int, unsigned long);
284 if (use_pde(pde)) {
285 compat_ioctl = pde->proc_fops->compat_ioctl;
286 if (compat_ioctl)
287 rv = compat_ioctl(file, cmd, arg);
288 unuse_pde(pde);
289 }
290 return rv;
291}
292#endif
293
294static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
295{
296 struct proc_dir_entry *pde = PDE(file_inode(file));
297 int rv = -EIO;
298 int (*mmap)(struct file *, struct vm_area_struct *);
299 if (use_pde(pde)) {
300 mmap = pde->proc_fops->mmap;
301 if (mmap)
302 rv = mmap(file, vma);
303 unuse_pde(pde);
304 }
305 return rv;
306}
307
308static unsigned long
309proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr,
310 unsigned long len, unsigned long pgoff,
311 unsigned long flags)
312{
313 struct proc_dir_entry *pde = PDE(file_inode(file));
314 unsigned long rv = -EIO;
315
316 if (use_pde(pde)) {
317 typeof(proc_reg_get_unmapped_area) *get_area;
318
319 get_area = pde->proc_fops->get_unmapped_area;
320#ifdef CONFIG_MMU
321 if (!get_area)
322 get_area = current->mm->get_unmapped_area;
323#endif
324
325 if (get_area)
326 rv = get_area(file, orig_addr, len, pgoff, flags);
327 else
328 rv = orig_addr;
329 unuse_pde(pde);
330 }
331 return rv;
332}
333
334static int proc_reg_open(struct inode *inode, struct file *file)
335{
336 struct proc_dir_entry *pde = PDE(inode);
337 int rv = 0;
338 int (*open)(struct inode *, struct file *);
339 int (*release)(struct inode *, struct file *);
340 struct pde_opener *pdeo;
341
342 /*
343 * Ensure that
344 * 1) PDE's ->release hook will be called no matter what
345 * either normally by close()/->release, or forcefully by
346 * rmmod/remove_proc_entry.
347 *
348 * 2) rmmod isn't blocked by opening file in /proc and sitting on
349 * the descriptor (including "rmmod foo </proc/foo" scenario).
350 *
351 * Save every "struct file" with custom ->release hook.
352 */
353 if (!use_pde(pde))
354 return -ENOENT;
355
356 release = pde->proc_fops->release;
357 if (release) {
358 pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL);
359 if (!pdeo) {
360 rv = -ENOMEM;
361 goto out_unuse;
362 }
363 }
364
365 open = pde->proc_fops->open;
366 if (open)
367 rv = open(inode, file);
368
369 if (release) {
370 if (rv == 0) {
371 /* To know what to release. */
372 pdeo->file = file;
373 pdeo->closing = false;
374 pdeo->c = NULL;
375 spin_lock(&pde->pde_unload_lock);
376 list_add(&pdeo->lh, &pde->pde_openers);
377 spin_unlock(&pde->pde_unload_lock);
378 } else
379 kmem_cache_free(pde_opener_cache, pdeo);
380 }
381
382out_unuse:
383 unuse_pde(pde);
384 return rv;
385}
386
387static int proc_reg_release(struct inode *inode, struct file *file)
388{
389 struct proc_dir_entry *pde = PDE(inode);
390 struct pde_opener *pdeo;
391 spin_lock(&pde->pde_unload_lock);
392 list_for_each_entry(pdeo, &pde->pde_openers, lh) {
393 if (pdeo->file == file) {
394 close_pdeo(pde, pdeo);
395 return 0;
396 }
397 }
398 spin_unlock(&pde->pde_unload_lock);
399 return 0;
400}
401
402static const struct file_operations proc_reg_file_ops = {
403 .llseek = proc_reg_llseek,
404 .read = proc_reg_read,
405 .write = proc_reg_write,
406 .poll = proc_reg_poll,
407 .unlocked_ioctl = proc_reg_unlocked_ioctl,
408#ifdef CONFIG_COMPAT
409 .compat_ioctl = proc_reg_compat_ioctl,
410#endif
411 .mmap = proc_reg_mmap,
412 .get_unmapped_area = proc_reg_get_unmapped_area,
413 .open = proc_reg_open,
414 .release = proc_reg_release,
415};
416
417#ifdef CONFIG_COMPAT
418static const struct file_operations proc_reg_file_ops_no_compat = {
419 .llseek = proc_reg_llseek,
420 .read = proc_reg_read,
421 .write = proc_reg_write,
422 .poll = proc_reg_poll,
423 .unlocked_ioctl = proc_reg_unlocked_ioctl,
424 .mmap = proc_reg_mmap,
425 .get_unmapped_area = proc_reg_get_unmapped_area,
426 .open = proc_reg_open,
427 .release = proc_reg_release,
428};
429#endif
430
431static void proc_put_link(void *p)
432{
433 unuse_pde(p);
434}
435
436static const char *proc_get_link(struct dentry *dentry,
437 struct inode *inode,
438 struct delayed_call *done)
439{
440 struct proc_dir_entry *pde = PDE(inode);
441 if (!use_pde(pde))
442 return ERR_PTR(-EINVAL);
443 set_delayed_call(done, proc_put_link, pde);
444 return pde->data;
445}
446
447const struct inode_operations proc_link_inode_operations = {
448 .get_link = proc_get_link,
449};
450
451struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
452{
453 struct inode *inode = new_inode_pseudo(sb);
454
455 if (inode) {
456 inode->i_ino = de->low_ino;
457 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
458 PROC_I(inode)->pde = de;
459
460 if (is_empty_pde(de)) {
461 make_empty_dir_inode(inode);
462 return inode;
463 }
464 if (de->mode) {
465 inode->i_mode = de->mode;
466 inode->i_uid = de->uid;
467 inode->i_gid = de->gid;
468 }
469 if (de->size)
470 inode->i_size = de->size;
471 if (de->nlink)
472 set_nlink(inode, de->nlink);
473 WARN_ON(!de->proc_iops);
474 inode->i_op = de->proc_iops;
475 if (de->proc_fops) {
476 if (S_ISREG(inode->i_mode)) {
477#ifdef CONFIG_COMPAT
478 if (!de->proc_fops->compat_ioctl)
479 inode->i_fop =
480 &proc_reg_file_ops_no_compat;
481 else
482#endif
483 inode->i_fop = &proc_reg_file_ops;
484 } else {
485 inode->i_fop = de->proc_fops;
486 }
487 }
488 } else
489 pde_put(de);
490 return inode;
491}
492
493int proc_fill_super(struct super_block *s, void *data, int silent)
494{
495 struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
496 struct inode *root_inode;
497 int ret;
498
499 if (!proc_parse_options(data, ns))
500 return -EINVAL;
501
502 /* User space would break if executables or devices appear on proc */
503 s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
504 s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC;
505 s->s_blocksize = 1024;
506 s->s_blocksize_bits = 10;
507 s->s_magic = PROC_SUPER_MAGIC;
508 s->s_op = &proc_sops;
509 s->s_time_gran = 1;
510
511 /*
512 * procfs isn't actually a stacking filesystem; however, there is
513 * too much magic going on inside it to permit stacking things on
514 * top of it
515 */
516 s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
517
518 pde_get(&proc_root);
519 root_inode = proc_get_inode(s, &proc_root);
520 if (!root_inode) {
521 pr_err("proc_fill_super: get root inode failed\n");
522 return -ENOMEM;
523 }
524
525 s->s_root = d_make_root(root_inode);
526 if (!s->s_root) {
527 pr_err("proc_fill_super: allocate dentry failed\n");
528 return -ENOMEM;
529 }
530
531 ret = proc_setup_self(s);
532 if (ret) {
533 return ret;
534 }
535 return proc_setup_thread_self(s);
536}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/proc/inode.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/cache.h>
9#include <linux/time.h>
10#include <linux/proc_fs.h>
11#include <linux/kernel.h>
12#include <linux/pid_namespace.h>
13#include <linux/mm.h>
14#include <linux/string.h>
15#include <linux/stat.h>
16#include <linux/completion.h>
17#include <linux/poll.h>
18#include <linux/printk.h>
19#include <linux/file.h>
20#include <linux/limits.h>
21#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/sysctl.h>
24#include <linux/seq_file.h>
25#include <linux/slab.h>
26#include <linux/mount.h>
27
28#include <linux/uaccess.h>
29
30#include "internal.h"
31
32static void proc_evict_inode(struct inode *inode)
33{
34 struct proc_dir_entry *de;
35 struct ctl_table_header *head;
36
37 truncate_inode_pages_final(&inode->i_data);
38 clear_inode(inode);
39
40 /* Stop tracking associated processes */
41 put_pid(PROC_I(inode)->pid);
42
43 /* Let go of any associated proc directory entry */
44 de = PDE(inode);
45 if (de)
46 pde_put(de);
47
48 head = PROC_I(inode)->sysctl;
49 if (head) {
50 RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL);
51 proc_sys_evict_inode(inode, head);
52 }
53}
54
55static struct kmem_cache *proc_inode_cachep __ro_after_init;
56static struct kmem_cache *pde_opener_cache __ro_after_init;
57
58static struct inode *proc_alloc_inode(struct super_block *sb)
59{
60 struct proc_inode *ei;
61
62 ei = kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL);
63 if (!ei)
64 return NULL;
65 ei->pid = NULL;
66 ei->fd = 0;
67 ei->op.proc_get_link = NULL;
68 ei->pde = NULL;
69 ei->sysctl = NULL;
70 ei->sysctl_entry = NULL;
71 ei->ns_ops = NULL;
72 return &ei->vfs_inode;
73}
74
75static void proc_free_inode(struct inode *inode)
76{
77 kmem_cache_free(proc_inode_cachep, PROC_I(inode));
78}
79
80static void init_once(void *foo)
81{
82 struct proc_inode *ei = (struct proc_inode *) foo;
83
84 inode_init_once(&ei->vfs_inode);
85}
86
87void __init proc_init_kmemcache(void)
88{
89 proc_inode_cachep = kmem_cache_create("proc_inode_cache",
90 sizeof(struct proc_inode),
91 0, (SLAB_RECLAIM_ACCOUNT|
92 SLAB_MEM_SPREAD|SLAB_ACCOUNT|
93 SLAB_PANIC),
94 init_once);
95 pde_opener_cache =
96 kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0,
97 SLAB_ACCOUNT|SLAB_PANIC, NULL);
98 proc_dir_entry_cache = kmem_cache_create_usercopy(
99 "proc_dir_entry", SIZEOF_PDE, 0, SLAB_PANIC,
100 offsetof(struct proc_dir_entry, inline_name),
101 SIZEOF_PDE_INLINE_NAME, NULL);
102 BUILD_BUG_ON(sizeof(struct proc_dir_entry) >= SIZEOF_PDE);
103}
104
105static int proc_show_options(struct seq_file *seq, struct dentry *root)
106{
107 struct super_block *sb = root->d_sb;
108 struct pid_namespace *pid = sb->s_fs_info;
109
110 if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
111 seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
112 if (pid->hide_pid != HIDEPID_OFF)
113 seq_printf(seq, ",hidepid=%u", pid->hide_pid);
114
115 return 0;
116}
117
118const struct super_operations proc_sops = {
119 .alloc_inode = proc_alloc_inode,
120 .free_inode = proc_free_inode,
121 .drop_inode = generic_delete_inode,
122 .evict_inode = proc_evict_inode,
123 .statfs = simple_statfs,
124 .show_options = proc_show_options,
125};
126
127enum {BIAS = -1U<<31};
128
129static inline int use_pde(struct proc_dir_entry *pde)
130{
131 return likely(atomic_inc_unless_negative(&pde->in_use));
132}
133
134static void unuse_pde(struct proc_dir_entry *pde)
135{
136 if (unlikely(atomic_dec_return(&pde->in_use) == BIAS))
137 complete(pde->pde_unload_completion);
138}
139
140/* pde is locked on entry, unlocked on exit */
141static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo)
142{
143 /*
144 * close() (proc_reg_release()) can't delete an entry and proceed:
145 * ->release hook needs to be available at the right moment.
146 *
147 * rmmod (remove_proc_entry() et al) can't delete an entry and proceed:
148 * "struct file" needs to be available at the right moment.
149 *
150 * Therefore, first process to enter this function does ->release() and
151 * signals its completion to the other process which does nothing.
152 */
153 if (pdeo->closing) {
154 /* somebody else is doing that, just wait */
155 DECLARE_COMPLETION_ONSTACK(c);
156 pdeo->c = &c;
157 spin_unlock(&pde->pde_unload_lock);
158 wait_for_completion(&c);
159 } else {
160 struct file *file;
161 struct completion *c;
162
163 pdeo->closing = true;
164 spin_unlock(&pde->pde_unload_lock);
165 file = pdeo->file;
166 pde->proc_fops->release(file_inode(file), file);
167 spin_lock(&pde->pde_unload_lock);
168 /* After ->release. */
169 list_del(&pdeo->lh);
170 c = pdeo->c;
171 spin_unlock(&pde->pde_unload_lock);
172 if (unlikely(c))
173 complete(c);
174 kmem_cache_free(pde_opener_cache, pdeo);
175 }
176}
177
178void proc_entry_rundown(struct proc_dir_entry *de)
179{
180 DECLARE_COMPLETION_ONSTACK(c);
181 /* Wait until all existing callers into module are done. */
182 de->pde_unload_completion = &c;
183 if (atomic_add_return(BIAS, &de->in_use) != BIAS)
184 wait_for_completion(&c);
185
186 /* ->pde_openers list can't grow from now on. */
187
188 spin_lock(&de->pde_unload_lock);
189 while (!list_empty(&de->pde_openers)) {
190 struct pde_opener *pdeo;
191 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
192 close_pdeo(de, pdeo);
193 spin_lock(&de->pde_unload_lock);
194 }
195 spin_unlock(&de->pde_unload_lock);
196}
197
198static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
199{
200 struct proc_dir_entry *pde = PDE(file_inode(file));
201 loff_t rv = -EINVAL;
202 if (use_pde(pde)) {
203 typeof_member(struct file_operations, llseek) llseek;
204
205 llseek = pde->proc_fops->llseek;
206 if (!llseek)
207 llseek = default_llseek;
208 rv = llseek(file, offset, whence);
209 unuse_pde(pde);
210 }
211 return rv;
212}
213
214static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
215{
216 struct proc_dir_entry *pde = PDE(file_inode(file));
217 ssize_t rv = -EIO;
218 if (use_pde(pde)) {
219 typeof_member(struct file_operations, read) read;
220
221 read = pde->proc_fops->read;
222 if (read)
223 rv = read(file, buf, count, ppos);
224 unuse_pde(pde);
225 }
226 return rv;
227}
228
229static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
230{
231 struct proc_dir_entry *pde = PDE(file_inode(file));
232 ssize_t rv = -EIO;
233 if (use_pde(pde)) {
234 typeof_member(struct file_operations, write) write;
235
236 write = pde->proc_fops->write;
237 if (write)
238 rv = write(file, buf, count, ppos);
239 unuse_pde(pde);
240 }
241 return rv;
242}
243
244static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts)
245{
246 struct proc_dir_entry *pde = PDE(file_inode(file));
247 __poll_t rv = DEFAULT_POLLMASK;
248 if (use_pde(pde)) {
249 typeof_member(struct file_operations, poll) poll;
250
251 poll = pde->proc_fops->poll;
252 if (poll)
253 rv = poll(file, pts);
254 unuse_pde(pde);
255 }
256 return rv;
257}
258
259static long proc_reg_unlocked_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 if (use_pde(pde)) {
264 typeof_member(struct file_operations, unlocked_ioctl) ioctl;
265
266 ioctl = pde->proc_fops->unlocked_ioctl;
267 if (ioctl)
268 rv = ioctl(file, cmd, arg);
269 unuse_pde(pde);
270 }
271 return rv;
272}
273
274#ifdef CONFIG_COMPAT
275static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
276{
277 struct proc_dir_entry *pde = PDE(file_inode(file));
278 long rv = -ENOTTY;
279 if (use_pde(pde)) {
280 typeof_member(struct file_operations, compat_ioctl) compat_ioctl;
281
282 compat_ioctl = pde->proc_fops->compat_ioctl;
283 if (compat_ioctl)
284 rv = compat_ioctl(file, cmd, arg);
285 unuse_pde(pde);
286 }
287 return rv;
288}
289#endif
290
291static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
292{
293 struct proc_dir_entry *pde = PDE(file_inode(file));
294 int rv = -EIO;
295 if (use_pde(pde)) {
296 typeof_member(struct file_operations, mmap) mmap;
297
298 mmap = pde->proc_fops->mmap;
299 if (mmap)
300 rv = mmap(file, vma);
301 unuse_pde(pde);
302 }
303 return rv;
304}
305
306static unsigned long
307proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr,
308 unsigned long len, unsigned long pgoff,
309 unsigned long flags)
310{
311 struct proc_dir_entry *pde = PDE(file_inode(file));
312 unsigned long rv = -EIO;
313
314 if (use_pde(pde)) {
315 typeof_member(struct file_operations, get_unmapped_area) get_area;
316
317 get_area = pde->proc_fops->get_unmapped_area;
318#ifdef CONFIG_MMU
319 if (!get_area)
320 get_area = current->mm->get_unmapped_area;
321#endif
322
323 if (get_area)
324 rv = get_area(file, orig_addr, len, pgoff, flags);
325 else
326 rv = orig_addr;
327 unuse_pde(pde);
328 }
329 return rv;
330}
331
332static int proc_reg_open(struct inode *inode, struct file *file)
333{
334 struct proc_dir_entry *pde = PDE(inode);
335 int rv = 0;
336 typeof_member(struct file_operations, open) open;
337 typeof_member(struct file_operations, release) release;
338 struct pde_opener *pdeo;
339
340 /*
341 * Ensure that
342 * 1) PDE's ->release hook will be called no matter what
343 * either normally by close()/->release, or forcefully by
344 * rmmod/remove_proc_entry.
345 *
346 * 2) rmmod isn't blocked by opening file in /proc and sitting on
347 * the descriptor (including "rmmod foo </proc/foo" scenario).
348 *
349 * Save every "struct file" with custom ->release hook.
350 */
351 if (!use_pde(pde))
352 return -ENOENT;
353
354 release = pde->proc_fops->release;
355 if (release) {
356 pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL);
357 if (!pdeo) {
358 rv = -ENOMEM;
359 goto out_unuse;
360 }
361 }
362
363 open = pde->proc_fops->open;
364 if (open)
365 rv = open(inode, file);
366
367 if (release) {
368 if (rv == 0) {
369 /* To know what to release. */
370 pdeo->file = file;
371 pdeo->closing = false;
372 pdeo->c = NULL;
373 spin_lock(&pde->pde_unload_lock);
374 list_add(&pdeo->lh, &pde->pde_openers);
375 spin_unlock(&pde->pde_unload_lock);
376 } else
377 kmem_cache_free(pde_opener_cache, pdeo);
378 }
379
380out_unuse:
381 unuse_pde(pde);
382 return rv;
383}
384
385static int proc_reg_release(struct inode *inode, struct file *file)
386{
387 struct proc_dir_entry *pde = PDE(inode);
388 struct pde_opener *pdeo;
389 spin_lock(&pde->pde_unload_lock);
390 list_for_each_entry(pdeo, &pde->pde_openers, lh) {
391 if (pdeo->file == file) {
392 close_pdeo(pde, pdeo);
393 return 0;
394 }
395 }
396 spin_unlock(&pde->pde_unload_lock);
397 return 0;
398}
399
400static const struct file_operations proc_reg_file_ops = {
401 .llseek = proc_reg_llseek,
402 .read = proc_reg_read,
403 .write = proc_reg_write,
404 .poll = proc_reg_poll,
405 .unlocked_ioctl = proc_reg_unlocked_ioctl,
406#ifdef CONFIG_COMPAT
407 .compat_ioctl = proc_reg_compat_ioctl,
408#endif
409 .mmap = proc_reg_mmap,
410 .get_unmapped_area = proc_reg_get_unmapped_area,
411 .open = proc_reg_open,
412 .release = proc_reg_release,
413};
414
415#ifdef CONFIG_COMPAT
416static const struct file_operations proc_reg_file_ops_no_compat = {
417 .llseek = proc_reg_llseek,
418 .read = proc_reg_read,
419 .write = proc_reg_write,
420 .poll = proc_reg_poll,
421 .unlocked_ioctl = proc_reg_unlocked_ioctl,
422 .mmap = proc_reg_mmap,
423 .get_unmapped_area = proc_reg_get_unmapped_area,
424 .open = proc_reg_open,
425 .release = proc_reg_release,
426};
427#endif
428
429static void proc_put_link(void *p)
430{
431 unuse_pde(p);
432}
433
434static const char *proc_get_link(struct dentry *dentry,
435 struct inode *inode,
436 struct delayed_call *done)
437{
438 struct proc_dir_entry *pde = PDE(inode);
439 if (!use_pde(pde))
440 return ERR_PTR(-EINVAL);
441 set_delayed_call(done, proc_put_link, pde);
442 return pde->data;
443}
444
445const struct inode_operations proc_link_inode_operations = {
446 .get_link = proc_get_link,
447};
448
449struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de)
450{
451 struct inode *inode = new_inode_pseudo(sb);
452
453 if (inode) {
454 inode->i_ino = de->low_ino;
455 inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
456 PROC_I(inode)->pde = de;
457
458 if (is_empty_pde(de)) {
459 make_empty_dir_inode(inode);
460 return inode;
461 }
462 if (de->mode) {
463 inode->i_mode = de->mode;
464 inode->i_uid = de->uid;
465 inode->i_gid = de->gid;
466 }
467 if (de->size)
468 inode->i_size = de->size;
469 if (de->nlink)
470 set_nlink(inode, de->nlink);
471 WARN_ON(!de->proc_iops);
472 inode->i_op = de->proc_iops;
473 if (de->proc_fops) {
474 if (S_ISREG(inode->i_mode)) {
475#ifdef CONFIG_COMPAT
476 if (!de->proc_fops->compat_ioctl)
477 inode->i_fop =
478 &proc_reg_file_ops_no_compat;
479 else
480#endif
481 inode->i_fop = &proc_reg_file_ops;
482 } else {
483 inode->i_fop = de->proc_fops;
484 }
485 }
486 } else
487 pde_put(de);
488 return inode;
489}