Commit | Line | Data |
---|---|---|
1da177e4 LT |
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> | |
97412950 | 10 | #include <linux/pid_namespace.h> |
1da177e4 LT |
11 | #include <linux/mm.h> |
12 | #include <linux/string.h> | |
13 | #include <linux/stat.h> | |
786d7e16 | 14 | #include <linux/completion.h> |
dd23aae4 | 15 | #include <linux/poll.h> |
87ebdc00 | 16 | #include <linux/printk.h> |
1da177e4 LT |
17 | #include <linux/file.h> |
18 | #include <linux/limits.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/module.h> | |
9043476f | 21 | #include <linux/sysctl.h> |
97412950 | 22 | #include <linux/seq_file.h> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
97412950 | 24 | #include <linux/mount.h> |
303eb7e2 | 25 | #include <linux/magic.h> |
1da177e4 | 26 | |
1da177e4 LT |
27 | #include <asm/uaccess.h> |
28 | ||
fee781e6 | 29 | #include "internal.h" |
1da177e4 | 30 | |
8267952b | 31 | static void proc_evict_inode(struct inode *inode) |
1da177e4 LT |
32 | { |
33 | struct proc_dir_entry *de; | |
dfef6dcd | 34 | struct ctl_table_header *head; |
64964528 | 35 | struct ns_common *ns; |
1da177e4 | 36 | |
91b0abe3 | 37 | truncate_inode_pages_final(&inode->i_data); |
dbd5768f | 38 | clear_inode(inode); |
fef26658 | 39 | |
99f89551 | 40 | /* Stop tracking associated processes */ |
13b41b09 | 41 | put_pid(PROC_I(inode)->pid); |
1da177e4 LT |
42 | |
43 | /* Let go of any associated proc directory entry */ | |
44 | de = PROC_I(inode)->pde; | |
99b76233 | 45 | if (de) |
135d5655 | 46 | pde_put(de); |
dfef6dcd AV |
47 | head = PROC_I(inode)->sysctl; |
48 | if (head) { | |
1c44dbc8 | 49 | RCU_INIT_POINTER(PROC_I(inode)->sysctl, NULL); |
dfef6dcd AV |
50 | sysctl_head_put(head); |
51 | } | |
6b4e306a | 52 | /* Release any associated namespace */ |
0bb80f24 | 53 | ns = PROC_I(inode)->ns.ns; |
33c42940 AV |
54 | if (ns && ns->ops) |
55 | ns->ops->put(ns); | |
1da177e4 LT |
56 | } |
57 | ||
e18b890b | 58 | static struct kmem_cache * proc_inode_cachep; |
1da177e4 LT |
59 | |
60 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
61 | { | |
62 | struct proc_inode *ei; | |
63 | struct inode *inode; | |
64 | ||
e94b1766 | 65 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
66 | if (!ei) |
67 | return NULL; | |
13b41b09 | 68 | ei->pid = NULL; |
aed7a6c4 | 69 | ei->fd = 0; |
1da177e4 LT |
70 | ei->op.proc_get_link = NULL; |
71 | ei->pde = NULL; | |
9043476f AV |
72 | ei->sysctl = NULL; |
73 | ei->sysctl_entry = NULL; | |
0bb80f24 DH |
74 | ei->ns.ns = NULL; |
75 | ei->ns.ns_ops = NULL; | |
1da177e4 LT |
76 | inode = &ei->vfs_inode; |
77 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
78 | return inode; | |
79 | } | |
80 | ||
fa0d7e3d | 81 | static void proc_i_callback(struct rcu_head *head) |
1da177e4 | 82 | { |
fa0d7e3d | 83 | struct inode *inode = container_of(head, struct inode, i_rcu); |
1da177e4 LT |
84 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); |
85 | } | |
86 | ||
fa0d7e3d NP |
87 | static void proc_destroy_inode(struct inode *inode) |
88 | { | |
89 | call_rcu(&inode->i_rcu, proc_i_callback); | |
90 | } | |
91 | ||
51cc5068 | 92 | static void init_once(void *foo) |
1da177e4 LT |
93 | { |
94 | struct proc_inode *ei = (struct proc_inode *) foo; | |
95 | ||
a35afb83 | 96 | inode_init_once(&ei->vfs_inode); |
1da177e4 | 97 | } |
20c2df83 | 98 | |
5bcd7ff9 | 99 | void __init proc_init_inodecache(void) |
1da177e4 LT |
100 | { |
101 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
102 | sizeof(struct proc_inode), | |
fffb60f9 | 103 | 0, (SLAB_RECLAIM_ACCOUNT| |
040b5c6f | 104 | SLAB_MEM_SPREAD|SLAB_PANIC), |
20c2df83 | 105 | init_once); |
1da177e4 LT |
106 | } |
107 | ||
97412950 VK |
108 | static int proc_show_options(struct seq_file *seq, struct dentry *root) |
109 | { | |
0499680a VK |
110 | struct super_block *sb = root->d_sb; |
111 | struct pid_namespace *pid = sb->s_fs_info; | |
112 | ||
dcb0f222 EB |
113 | if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID)) |
114 | seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid)); | |
0499680a VK |
115 | if (pid->hide_pid != 0) |
116 | seq_printf(seq, ",hidepid=%u", pid->hide_pid); | |
117 | ||
97412950 VK |
118 | return 0; |
119 | } | |
120 | ||
ee9b6d61 | 121 | static const struct super_operations proc_sops = { |
1da177e4 LT |
122 | .alloc_inode = proc_alloc_inode, |
123 | .destroy_inode = proc_destroy_inode, | |
1da177e4 | 124 | .drop_inode = generic_delete_inode, |
8267952b | 125 | .evict_inode = proc_evict_inode, |
1da177e4 | 126 | .statfs = simple_statfs, |
97412950 VK |
127 | .remount_fs = proc_remount, |
128 | .show_options = proc_show_options, | |
1da177e4 LT |
129 | }; |
130 | ||
866ad9a7 AV |
131 | enum {BIAS = -1U<<31}; |
132 | ||
133 | static inline int use_pde(struct proc_dir_entry *pde) | |
134 | { | |
05c0ae21 | 135 | return atomic_inc_unless_negative(&pde->in_use); |
881adb85 AD |
136 | } |
137 | ||
866ad9a7 | 138 | static void unuse_pde(struct proc_dir_entry *pde) |
881adb85 | 139 | { |
05c0ae21 AV |
140 | if (atomic_dec_return(&pde->in_use) == BIAS) |
141 | complete(pde->pde_unload_completion); | |
786d7e16 AD |
142 | } |
143 | ||
ca469f35 AV |
144 | /* pde is locked */ |
145 | static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo) | |
146 | { | |
05c0ae21 | 147 | if (pdeo->closing) { |
ca469f35 | 148 | /* somebody else is doing that, just wait */ |
05c0ae21 AV |
149 | DECLARE_COMPLETION_ONSTACK(c); |
150 | pdeo->c = &c; | |
ca469f35 | 151 | spin_unlock(&pde->pde_unload_lock); |
05c0ae21 | 152 | wait_for_completion(&c); |
ca469f35 | 153 | spin_lock(&pde->pde_unload_lock); |
ca469f35 AV |
154 | } else { |
155 | struct file *file; | |
05c0ae21 | 156 | pdeo->closing = 1; |
ca469f35 AV |
157 | spin_unlock(&pde->pde_unload_lock); |
158 | file = pdeo->file; | |
159 | pde->proc_fops->release(file_inode(file), file); | |
160 | spin_lock(&pde->pde_unload_lock); | |
161 | list_del_init(&pdeo->lh); | |
05c0ae21 AV |
162 | if (pdeo->c) |
163 | complete(pdeo->c); | |
ca469f35 | 164 | kfree(pdeo); |
05c0ae21 | 165 | } |
ca469f35 AV |
166 | } |
167 | ||
866ad9a7 | 168 | void proc_entry_rundown(struct proc_dir_entry *de) |
786d7e16 | 169 | { |
05c0ae21 | 170 | DECLARE_COMPLETION_ONSTACK(c); |
866ad9a7 | 171 | /* Wait until all existing callers into module are done. */ |
05c0ae21 AV |
172 | de->pde_unload_completion = &c; |
173 | if (atomic_add_return(BIAS, &de->in_use) != BIAS) | |
174 | wait_for_completion(&c); | |
786d7e16 | 175 | |
05c0ae21 | 176 | spin_lock(&de->pde_unload_lock); |
866ad9a7 AV |
177 | while (!list_empty(&de->pde_openers)) { |
178 | struct pde_opener *pdeo; | |
866ad9a7 | 179 | pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); |
ca469f35 | 180 | close_pdeo(de, pdeo); |
866ad9a7 AV |
181 | } |
182 | spin_unlock(&de->pde_unload_lock); | |
786d7e16 AD |
183 | } |
184 | ||
866ad9a7 AV |
185 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) |
186 | { | |
187 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
188 | loff_t rv = -EINVAL; | |
189 | if (use_pde(pde)) { | |
190 | loff_t (*llseek)(struct file *, loff_t, int); | |
191 | llseek = pde->proc_fops->llseek; | |
192 | if (!llseek) | |
193 | llseek = default_llseek; | |
194 | rv = llseek(file, offset, whence); | |
195 | unuse_pde(pde); | |
196 | } | |
786d7e16 AD |
197 | return rv; |
198 | } | |
199 | ||
866ad9a7 | 200 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
786d7e16 | 201 | { |
866ad9a7 | 202 | ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); |
496ad9aa | 203 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 204 | ssize_t rv = -EIO; |
866ad9a7 AV |
205 | if (use_pde(pde)) { |
206 | read = pde->proc_fops->read; | |
207 | if (read) | |
208 | rv = read(file, buf, count, ppos); | |
209 | unuse_pde(pde); | |
786d7e16 | 210 | } |
866ad9a7 AV |
211 | return rv; |
212 | } | |
786d7e16 | 213 | |
866ad9a7 AV |
214 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
215 | { | |
216 | ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); | |
217 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
218 | ssize_t rv = -EIO; | |
219 | if (use_pde(pde)) { | |
220 | write = pde->proc_fops->write; | |
221 | if (write) | |
222 | rv = write(file, buf, count, ppos); | |
223 | unuse_pde(pde); | |
224 | } | |
786d7e16 AD |
225 | return rv; |
226 | } | |
227 | ||
228 | static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts) | |
229 | { | |
496ad9aa | 230 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
dd23aae4 | 231 | unsigned int rv = DEFAULT_POLLMASK; |
786d7e16 | 232 | unsigned int (*poll)(struct file *, struct poll_table_struct *); |
866ad9a7 AV |
233 | if (use_pde(pde)) { |
234 | poll = pde->proc_fops->poll; | |
235 | if (poll) | |
236 | rv = poll(file, pts); | |
237 | unuse_pde(pde); | |
786d7e16 | 238 | } |
786d7e16 AD |
239 | return rv; |
240 | } | |
241 | ||
242 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
243 | { | |
496ad9aa | 244 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 245 | long rv = -ENOTTY; |
b19dd42f | 246 | long (*ioctl)(struct file *, unsigned int, unsigned long); |
866ad9a7 AV |
247 | if (use_pde(pde)) { |
248 | ioctl = pde->proc_fops->unlocked_ioctl; | |
249 | if (ioctl) | |
250 | rv = ioctl(file, cmd, arg); | |
251 | unuse_pde(pde); | |
786d7e16 | 252 | } |
786d7e16 AD |
253 | return rv; |
254 | } | |
255 | ||
256 | #ifdef CONFIG_COMPAT | |
257 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
258 | { | |
496ad9aa | 259 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 AD |
260 | long rv = -ENOTTY; |
261 | long (*compat_ioctl)(struct file *, unsigned int, unsigned long); | |
866ad9a7 AV |
262 | if (use_pde(pde)) { |
263 | compat_ioctl = pde->proc_fops->compat_ioctl; | |
264 | if (compat_ioctl) | |
265 | rv = compat_ioctl(file, cmd, arg); | |
266 | unuse_pde(pde); | |
786d7e16 | 267 | } |
786d7e16 AD |
268 | return rv; |
269 | } | |
270 | #endif | |
271 | ||
272 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) | |
273 | { | |
496ad9aa | 274 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 AD |
275 | int rv = -EIO; |
276 | int (*mmap)(struct file *, struct vm_area_struct *); | |
866ad9a7 AV |
277 | if (use_pde(pde)) { |
278 | mmap = pde->proc_fops->mmap; | |
279 | if (mmap) | |
280 | rv = mmap(file, vma); | |
281 | unuse_pde(pde); | |
786d7e16 | 282 | } |
786d7e16 AD |
283 | return rv; |
284 | } | |
285 | ||
5721cf84 HD |
286 | static unsigned long |
287 | proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, | |
288 | unsigned long len, unsigned long pgoff, | |
289 | unsigned long flags) | |
c4fe2448 AD |
290 | { |
291 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
2cbe3b0a | 292 | unsigned long rv = -EIO; |
ae5758a1 | 293 | |
c4fe2448 | 294 | if (use_pde(pde)) { |
ae5758a1 JB |
295 | typeof(proc_reg_get_unmapped_area) *get_area; |
296 | ||
297 | get_area = pde->proc_fops->get_unmapped_area; | |
fad1a86e | 298 | #ifdef CONFIG_MMU |
ae5758a1 JB |
299 | if (!get_area) |
300 | get_area = current->mm->get_unmapped_area; | |
fad1a86e | 301 | #endif |
ae5758a1 | 302 | |
5721cf84 HD |
303 | if (get_area) |
304 | rv = get_area(file, orig_addr, len, pgoff, flags); | |
ae5758a1 JB |
305 | else |
306 | rv = orig_addr; | |
c4fe2448 AD |
307 | unuse_pde(pde); |
308 | } | |
309 | return rv; | |
310 | } | |
311 | ||
786d7e16 AD |
312 | static int proc_reg_open(struct inode *inode, struct file *file) |
313 | { | |
314 | struct proc_dir_entry *pde = PDE(inode); | |
315 | int rv = 0; | |
316 | int (*open)(struct inode *, struct file *); | |
881adb85 AD |
317 | int (*release)(struct inode *, struct file *); |
318 | struct pde_opener *pdeo; | |
319 | ||
320 | /* | |
321 | * What for, you ask? Well, we can have open, rmmod, remove_proc_entry | |
322 | * sequence. ->release won't be called because ->proc_fops will be | |
323 | * cleared. Depending on complexity of ->release, consequences vary. | |
324 | * | |
325 | * We can't wait for mercy when close will be done for real, it's | |
326 | * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release | |
327 | * by hand in remove_proc_entry(). For this, save opener's credentials | |
328 | * for later. | |
329 | */ | |
05c0ae21 | 330 | pdeo = kzalloc(sizeof(struct pde_opener), GFP_KERNEL); |
881adb85 AD |
331 | if (!pdeo) |
332 | return -ENOMEM; | |
786d7e16 | 333 | |
866ad9a7 | 334 | if (!use_pde(pde)) { |
881adb85 | 335 | kfree(pdeo); |
d2857e79 | 336 | return -ENOENT; |
786d7e16 | 337 | } |
786d7e16 | 338 | open = pde->proc_fops->open; |
881adb85 | 339 | release = pde->proc_fops->release; |
786d7e16 AD |
340 | |
341 | if (open) | |
342 | rv = open(inode, file); | |
343 | ||
881adb85 AD |
344 | if (rv == 0 && release) { |
345 | /* To know what to release. */ | |
881adb85 AD |
346 | pdeo->file = file; |
347 | /* Strictly for "too late" ->release in proc_reg_release(). */ | |
05c0ae21 | 348 | spin_lock(&pde->pde_unload_lock); |
881adb85 | 349 | list_add(&pdeo->lh, &pde->pde_openers); |
05c0ae21 | 350 | spin_unlock(&pde->pde_unload_lock); |
881adb85 AD |
351 | } else |
352 | kfree(pdeo); | |
05c0ae21 AV |
353 | |
354 | unuse_pde(pde); | |
786d7e16 AD |
355 | return rv; |
356 | } | |
357 | ||
358 | static int proc_reg_release(struct inode *inode, struct file *file) | |
359 | { | |
360 | struct proc_dir_entry *pde = PDE(inode); | |
881adb85 | 361 | struct pde_opener *pdeo; |
786d7e16 | 362 | spin_lock(&pde->pde_unload_lock); |
ca469f35 AV |
363 | list_for_each_entry(pdeo, &pde->pde_openers, lh) { |
364 | if (pdeo->file == file) { | |
365 | close_pdeo(pde, pdeo); | |
366 | break; | |
367 | } | |
881adb85 | 368 | } |
786d7e16 | 369 | spin_unlock(&pde->pde_unload_lock); |
ca469f35 | 370 | return 0; |
786d7e16 AD |
371 | } |
372 | ||
373 | static const struct file_operations proc_reg_file_ops = { | |
374 | .llseek = proc_reg_llseek, | |
375 | .read = proc_reg_read, | |
376 | .write = proc_reg_write, | |
377 | .poll = proc_reg_poll, | |
378 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
379 | #ifdef CONFIG_COMPAT | |
380 | .compat_ioctl = proc_reg_compat_ioctl, | |
381 | #endif | |
382 | .mmap = proc_reg_mmap, | |
c4fe2448 | 383 | .get_unmapped_area = proc_reg_get_unmapped_area, |
786d7e16 AD |
384 | .open = proc_reg_open, |
385 | .release = proc_reg_release, | |
386 | }; | |
387 | ||
778f3dd5 DM |
388 | #ifdef CONFIG_COMPAT |
389 | static const struct file_operations proc_reg_file_ops_no_compat = { | |
390 | .llseek = proc_reg_llseek, | |
391 | .read = proc_reg_read, | |
392 | .write = proc_reg_write, | |
393 | .poll = proc_reg_poll, | |
394 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
395 | .mmap = proc_reg_mmap, | |
c4fe2448 | 396 | .get_unmapped_area = proc_reg_get_unmapped_area, |
778f3dd5 DM |
397 | .open = proc_reg_open, |
398 | .release = proc_reg_release, | |
399 | }; | |
400 | #endif | |
401 | ||
6d1b6e4e | 402 | struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) |
1da177e4 | 403 | { |
51f0885e | 404 | struct inode *inode = new_inode_pseudo(sb); |
1da177e4 | 405 | |
51f0885e LT |
406 | if (inode) { |
407 | inode->i_ino = de->low_ino; | |
a1d4aebb | 408 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
a1d4aebb | 409 | PROC_I(inode)->pde = de; |
5e971dce AD |
410 | |
411 | if (de->mode) { | |
412 | inode->i_mode = de->mode; | |
413 | inode->i_uid = de->uid; | |
414 | inode->i_gid = de->gid; | |
415 | } | |
416 | if (de->size) | |
417 | inode->i_size = de->size; | |
418 | if (de->nlink) | |
bfe86848 | 419 | set_nlink(inode, de->nlink); |
b6cdc731 AV |
420 | WARN_ON(!de->proc_iops); |
421 | inode->i_op = de->proc_iops; | |
5e971dce AD |
422 | if (de->proc_fops) { |
423 | if (S_ISREG(inode->i_mode)) { | |
778f3dd5 | 424 | #ifdef CONFIG_COMPAT |
5e971dce AD |
425 | if (!de->proc_fops->compat_ioctl) |
426 | inode->i_fop = | |
427 | &proc_reg_file_ops_no_compat; | |
428 | else | |
778f3dd5 | 429 | #endif |
5e971dce AD |
430 | inode->i_fop = &proc_reg_file_ops; |
431 | } else { | |
432 | inode->i_fop = de->proc_fops; | |
778f3dd5 | 433 | } |
786d7e16 | 434 | } |
99b76233 | 435 | } else |
135d5655 | 436 | pde_put(de); |
1da177e4 | 437 | return inode; |
d3d009cb | 438 | } |
1da177e4 | 439 | |
07543f5c | 440 | int proc_fill_super(struct super_block *s) |
1da177e4 | 441 | { |
87e0aab3 | 442 | struct inode *root_inode; |
0097875b | 443 | int ret; |
87e0aab3 | 444 | |
92d03285 | 445 | s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC; |
1da177e4 LT |
446 | s->s_blocksize = 1024; |
447 | s->s_blocksize_bits = 10; | |
448 | s->s_magic = PROC_SUPER_MAGIC; | |
449 | s->s_op = &proc_sops; | |
450 | s->s_time_gran = 1; | |
451 | ||
135d5655 | 452 | pde_get(&proc_root); |
87e0aab3 MP |
453 | root_inode = proc_get_inode(s, &proc_root); |
454 | if (!root_inode) { | |
87ebdc00 | 455 | pr_err("proc_fill_super: get root inode failed\n"); |
87e0aab3 MP |
456 | return -ENOMEM; |
457 | } | |
1da177e4 | 458 | |
87e0aab3 MP |
459 | s->s_root = d_make_root(root_inode); |
460 | if (!s->s_root) { | |
87ebdc00 | 461 | pr_err("proc_fill_super: allocate dentry failed\n"); |
87e0aab3 MP |
462 | return -ENOMEM; |
463 | } | |
464 | ||
0097875b EB |
465 | ret = proc_setup_self(s); |
466 | if (ret) { | |
467 | return ret; | |
468 | } | |
469 | return proc_setup_thread_self(s); | |
1da177e4 | 470 | } |