Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/fs/proc/inode.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | */ | |
7 | ||
efb1a57d | 8 | #include <linux/cache.h> |
1da177e4 LT |
9 | #include <linux/time.h> |
10 | #include <linux/proc_fs.h> | |
11 | #include <linux/kernel.h> | |
97412950 | 12 | #include <linux/pid_namespace.h> |
1da177e4 LT |
13 | #include <linux/mm.h> |
14 | #include <linux/string.h> | |
15 | #include <linux/stat.h> | |
786d7e16 | 16 | #include <linux/completion.h> |
dd23aae4 | 17 | #include <linux/poll.h> |
87ebdc00 | 18 | #include <linux/printk.h> |
1da177e4 LT |
19 | #include <linux/file.h> |
20 | #include <linux/limits.h> | |
21 | #include <linux/init.h> | |
22 | #include <linux/module.h> | |
9043476f | 23 | #include <linux/sysctl.h> |
97412950 | 24 | #include <linux/seq_file.h> |
5a0e3ad6 | 25 | #include <linux/slab.h> |
97412950 | 26 | #include <linux/mount.h> |
1c6c4d11 | 27 | #include <linux/bug.h> |
1da177e4 | 28 | |
7c0f6ba6 | 29 | #include <linux/uaccess.h> |
1da177e4 | 30 | |
fee781e6 | 31 | #include "internal.h" |
1da177e4 | 32 | |
8267952b | 33 | static void proc_evict_inode(struct inode *inode) |
1da177e4 LT |
34 | { |
35 | struct proc_dir_entry *de; | |
dfef6dcd | 36 | struct ctl_table_header *head; |
71448011 | 37 | struct proc_inode *ei = PROC_I(inode); |
1da177e4 | 38 | |
91b0abe3 | 39 | truncate_inode_pages_final(&inode->i_data); |
dbd5768f | 40 | clear_inode(inode); |
fef26658 | 41 | |
99f89551 | 42 | /* Stop tracking associated processes */ |
71448011 | 43 | if (ei->pid) { |
7bc3e6e5 | 44 | proc_pid_evict_inode(ei); |
71448011 EB |
45 | ei->pid = NULL; |
46 | } | |
1da177e4 LT |
47 | |
48 | /* Let go of any associated proc directory entry */ | |
71448011 EB |
49 | de = ei->pde; |
50 | if (de) { | |
135d5655 | 51 | pde_put(de); |
71448011 EB |
52 | ei->pde = NULL; |
53 | } | |
d6cffbbe | 54 | |
71448011 | 55 | head = ei->sysctl; |
dfef6dcd | 56 | if (head) { |
71448011 | 57 | RCU_INIT_POINTER(ei->sysctl, NULL); |
d6cffbbe | 58 | proc_sys_evict_inode(inode, head); |
dfef6dcd | 59 | } |
1da177e4 LT |
60 | } |
61 | ||
efb1a57d | 62 | static struct kmem_cache *proc_inode_cachep __ro_after_init; |
195b8cf0 | 63 | static struct kmem_cache *pde_opener_cache __ro_after_init; |
1da177e4 LT |
64 | |
65 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
66 | { | |
67 | struct proc_inode *ei; | |
1da177e4 | 68 | |
f245e1c1 | 69 | ei = kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
70 | if (!ei) |
71 | return NULL; | |
13b41b09 | 72 | ei->pid = NULL; |
aed7a6c4 | 73 | ei->fd = 0; |
1da177e4 LT |
74 | ei->op.proc_get_link = NULL; |
75 | ei->pde = NULL; | |
9043476f AV |
76 | ei->sysctl = NULL; |
77 | ei->sysctl_entry = NULL; | |
0afa5ca8 | 78 | INIT_HLIST_NODE(&ei->sibling_inodes); |
3d3d35b1 | 79 | ei->ns_ops = NULL; |
230f72e9 | 80 | return &ei->vfs_inode; |
1da177e4 LT |
81 | } |
82 | ||
4aa6b55c | 83 | static void proc_free_inode(struct inode *inode) |
1da177e4 LT |
84 | { |
85 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); | |
86 | } | |
87 | ||
51cc5068 | 88 | static void init_once(void *foo) |
1da177e4 LT |
89 | { |
90 | struct proc_inode *ei = (struct proc_inode *) foo; | |
91 | ||
a35afb83 | 92 | inode_init_once(&ei->vfs_inode); |
1da177e4 | 93 | } |
20c2df83 | 94 | |
195b8cf0 | 95 | void __init proc_init_kmemcache(void) |
1da177e4 LT |
96 | { |
97 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
98 | sizeof(struct proc_inode), | |
fffb60f9 | 99 | 0, (SLAB_RECLAIM_ACCOUNT| |
5d097056 VD |
100 | SLAB_MEM_SPREAD|SLAB_ACCOUNT| |
101 | SLAB_PANIC), | |
20c2df83 | 102 | init_once); |
195b8cf0 AD |
103 | pde_opener_cache = |
104 | kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0, | |
2acddbe8 | 105 | SLAB_ACCOUNT|SLAB_PANIC, NULL); |
b4884f23 | 106 | proc_dir_entry_cache = kmem_cache_create_usercopy( |
2d6e4e82 AD |
107 | "proc_dir_entry", SIZEOF_PDE, 0, SLAB_PANIC, |
108 | offsetof(struct proc_dir_entry, inline_name), | |
109 | SIZEOF_PDE_INLINE_NAME, NULL); | |
110 | BUILD_BUG_ON(sizeof(struct proc_dir_entry) >= SIZEOF_PDE); | |
1da177e4 LT |
111 | } |
112 | ||
f90f3caf | 113 | void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock) |
26dbc60f EB |
114 | { |
115 | struct inode *inode; | |
116 | struct proc_inode *ei; | |
117 | struct hlist_node *node; | |
080f6276 | 118 | struct super_block *old_sb = NULL; |
26dbc60f EB |
119 | |
120 | rcu_read_lock(); | |
121 | for (;;) { | |
080f6276 | 122 | struct super_block *sb; |
26dbc60f EB |
123 | node = hlist_first_rcu(inodes); |
124 | if (!node) | |
125 | break; | |
126 | ei = hlist_entry(node, struct proc_inode, sibling_inodes); | |
127 | spin_lock(lock); | |
128 | hlist_del_init_rcu(&ei->sibling_inodes); | |
129 | spin_unlock(lock); | |
130 | ||
131 | inode = &ei->vfs_inode; | |
132 | sb = inode->i_sb; | |
080f6276 | 133 | if ((sb != old_sb) && !atomic_inc_not_zero(&sb->s_active)) |
26dbc60f EB |
134 | continue; |
135 | inode = igrab(inode); | |
136 | rcu_read_unlock(); | |
080f6276 EB |
137 | if (sb != old_sb) { |
138 | if (old_sb) | |
139 | deactivate_super(old_sb); | |
140 | old_sb = sb; | |
141 | } | |
26dbc60f | 142 | if (unlikely(!inode)) { |
26dbc60f EB |
143 | rcu_read_lock(); |
144 | continue; | |
145 | } | |
146 | ||
f90f3caf EB |
147 | if (S_ISDIR(inode->i_mode)) { |
148 | struct dentry *dir = d_find_any_alias(inode); | |
149 | if (dir) { | |
150 | d_invalidate(dir); | |
151 | dput(dir); | |
152 | } | |
153 | } else { | |
154 | struct dentry *dentry; | |
155 | while ((dentry = d_find_alias(inode))) { | |
156 | d_invalidate(dentry); | |
157 | dput(dentry); | |
158 | } | |
159 | } | |
26dbc60f | 160 | iput(inode); |
26dbc60f EB |
161 | |
162 | rcu_read_lock(); | |
163 | } | |
164 | rcu_read_unlock(); | |
080f6276 EB |
165 | if (old_sb) |
166 | deactivate_super(old_sb); | |
26dbc60f EB |
167 | } |
168 | ||
e61bb8b3 | 169 | static inline const char *hidepid2str(enum proc_hidepid v) |
1c6c4d11 AG |
170 | { |
171 | switch (v) { | |
172 | case HIDEPID_OFF: return "off"; | |
173 | case HIDEPID_NO_ACCESS: return "noaccess"; | |
174 | case HIDEPID_INVISIBLE: return "invisible"; | |
175 | case HIDEPID_NOT_PTRACEABLE: return "ptraceable"; | |
176 | } | |
177 | WARN_ONCE(1, "bad hide_pid value: %d\n", v); | |
178 | return "unknown"; | |
179 | } | |
180 | ||
97412950 VK |
181 | static int proc_show_options(struct seq_file *seq, struct dentry *root) |
182 | { | |
fa10fed3 | 183 | struct proc_fs_info *fs_info = proc_sb_info(root->d_sb); |
0499680a | 184 | |
fa10fed3 AG |
185 | if (!gid_eq(fs_info->pid_gid, GLOBAL_ROOT_GID)) |
186 | seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, fs_info->pid_gid)); | |
187 | if (fs_info->hide_pid != HIDEPID_OFF) | |
1c6c4d11 | 188 | seq_printf(seq, ",hidepid=%s", hidepid2str(fs_info->hide_pid)); |
6814ef2d AG |
189 | if (fs_info->pidonly != PROC_PIDONLY_OFF) |
190 | seq_printf(seq, ",subset=pid"); | |
0499680a | 191 | |
97412950 VK |
192 | return 0; |
193 | } | |
194 | ||
60a3c3a5 | 195 | const struct super_operations proc_sops = { |
1da177e4 | 196 | .alloc_inode = proc_alloc_inode, |
4aa6b55c | 197 | .free_inode = proc_free_inode, |
1da177e4 | 198 | .drop_inode = generic_delete_inode, |
8267952b | 199 | .evict_inode = proc_evict_inode, |
1da177e4 | 200 | .statfs = simple_statfs, |
97412950 | 201 | .show_options = proc_show_options, |
1da177e4 LT |
202 | }; |
203 | ||
866ad9a7 AV |
204 | enum {BIAS = -1U<<31}; |
205 | ||
206 | static inline int use_pde(struct proc_dir_entry *pde) | |
207 | { | |
15b158b4 | 208 | return likely(atomic_inc_unless_negative(&pde->in_use)); |
881adb85 AD |
209 | } |
210 | ||
866ad9a7 | 211 | static void unuse_pde(struct proc_dir_entry *pde) |
881adb85 | 212 | { |
15b158b4 | 213 | if (unlikely(atomic_dec_return(&pde->in_use) == BIAS)) |
05c0ae21 | 214 | complete(pde->pde_unload_completion); |
786d7e16 AD |
215 | } |
216 | ||
2f897424 | 217 | /* pde is locked on entry, unlocked on exit */ |
ca469f35 | 218 | static void close_pdeo(struct proc_dir_entry *pde, struct pde_opener *pdeo) |
904f394e | 219 | __releases(&pde->pde_unload_lock) |
ca469f35 | 220 | { |
492b2da6 AD |
221 | /* |
222 | * close() (proc_reg_release()) can't delete an entry and proceed: | |
223 | * ->release hook needs to be available at the right moment. | |
224 | * | |
225 | * rmmod (remove_proc_entry() et al) can't delete an entry and proceed: | |
226 | * "struct file" needs to be available at the right moment. | |
227 | * | |
228 | * Therefore, first process to enter this function does ->release() and | |
229 | * signals its completion to the other process which does nothing. | |
230 | */ | |
05c0ae21 | 231 | if (pdeo->closing) { |
ca469f35 | 232 | /* somebody else is doing that, just wait */ |
05c0ae21 AV |
233 | DECLARE_COMPLETION_ONSTACK(c); |
234 | pdeo->c = &c; | |
ca469f35 | 235 | spin_unlock(&pde->pde_unload_lock); |
05c0ae21 | 236 | wait_for_completion(&c); |
ca469f35 AV |
237 | } else { |
238 | struct file *file; | |
2f897424 AD |
239 | struct completion *c; |
240 | ||
f5887c71 | 241 | pdeo->closing = true; |
ca469f35 AV |
242 | spin_unlock(&pde->pde_unload_lock); |
243 | file = pdeo->file; | |
d56c0d45 | 244 | pde->proc_ops->proc_release(file_inode(file), file); |
ca469f35 | 245 | spin_lock(&pde->pde_unload_lock); |
492b2da6 | 246 | /* After ->release. */ |
06a0c417 | 247 | list_del(&pdeo->lh); |
2f897424 AD |
248 | c = pdeo->c; |
249 | spin_unlock(&pde->pde_unload_lock); | |
250 | if (unlikely(c)) | |
251 | complete(c); | |
195b8cf0 | 252 | kmem_cache_free(pde_opener_cache, pdeo); |
05c0ae21 | 253 | } |
ca469f35 AV |
254 | } |
255 | ||
866ad9a7 | 256 | void proc_entry_rundown(struct proc_dir_entry *de) |
786d7e16 | 257 | { |
05c0ae21 | 258 | DECLARE_COMPLETION_ONSTACK(c); |
866ad9a7 | 259 | /* Wait until all existing callers into module are done. */ |
05c0ae21 AV |
260 | de->pde_unload_completion = &c; |
261 | if (atomic_add_return(BIAS, &de->in_use) != BIAS) | |
262 | wait_for_completion(&c); | |
786d7e16 | 263 | |
492b2da6 AD |
264 | /* ->pde_openers list can't grow from now on. */ |
265 | ||
05c0ae21 | 266 | spin_lock(&de->pde_unload_lock); |
866ad9a7 AV |
267 | while (!list_empty(&de->pde_openers)) { |
268 | struct pde_opener *pdeo; | |
866ad9a7 | 269 | pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); |
ca469f35 | 270 | close_pdeo(de, pdeo); |
2f897424 | 271 | spin_lock(&de->pde_unload_lock); |
866ad9a7 AV |
272 | } |
273 | spin_unlock(&de->pde_unload_lock); | |
786d7e16 AD |
274 | } |
275 | ||
d919b33d AD |
276 | static loff_t pde_lseek(struct proc_dir_entry *pde, struct file *file, loff_t offset, int whence) |
277 | { | |
278 | typeof_member(struct proc_ops, proc_lseek) lseek; | |
279 | ||
280 | lseek = pde->proc_ops->proc_lseek; | |
281 | if (!lseek) | |
282 | lseek = default_llseek; | |
283 | return lseek(file, offset, whence); | |
284 | } | |
285 | ||
866ad9a7 AV |
286 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) |
287 | { | |
288 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
289 | loff_t rv = -EINVAL; | |
9af27b28 | 290 | |
d919b33d AD |
291 | if (pde_is_permanent(pde)) { |
292 | return pde_lseek(pde, file, offset, whence); | |
293 | } else if (use_pde(pde)) { | |
294 | rv = pde_lseek(pde, file, offset, whence); | |
866ad9a7 AV |
295 | unuse_pde(pde); |
296 | } | |
786d7e16 AD |
297 | return rv; |
298 | } | |
299 | ||
fd5a13f4 CH |
300 | static ssize_t proc_reg_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
301 | { | |
302 | struct proc_dir_entry *pde = PDE(file_inode(iocb->ki_filp)); | |
303 | ssize_t ret; | |
304 | ||
305 | if (pde_is_permanent(pde)) | |
306 | return pde->proc_ops->proc_read_iter(iocb, iter); | |
307 | ||
308 | if (!use_pde(pde)) | |
309 | return -EIO; | |
310 | ret = pde->proc_ops->proc_read_iter(iocb, iter); | |
311 | unuse_pde(pde); | |
312 | return ret; | |
313 | } | |
314 | ||
d919b33d AD |
315 | static ssize_t pde_read(struct proc_dir_entry *pde, struct file *file, char __user *buf, size_t count, loff_t *ppos) |
316 | { | |
317 | typeof_member(struct proc_ops, proc_read) read; | |
318 | ||
319 | read = pde->proc_ops->proc_read; | |
320 | if (read) | |
321 | return read(file, buf, count, ppos); | |
322 | return -EIO; | |
323 | } | |
324 | ||
866ad9a7 | 325 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
786d7e16 | 326 | { |
496ad9aa | 327 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 328 | ssize_t rv = -EIO; |
9af27b28 | 329 | |
d919b33d AD |
330 | if (pde_is_permanent(pde)) { |
331 | return pde_read(pde, file, buf, count, ppos); | |
332 | } else if (use_pde(pde)) { | |
333 | rv = pde_read(pde, file, buf, count, ppos); | |
866ad9a7 | 334 | unuse_pde(pde); |
786d7e16 | 335 | } |
866ad9a7 AV |
336 | return rv; |
337 | } | |
786d7e16 | 338 | |
d919b33d AD |
339 | static ssize_t pde_write(struct proc_dir_entry *pde, struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
340 | { | |
341 | typeof_member(struct proc_ops, proc_write) write; | |
342 | ||
343 | write = pde->proc_ops->proc_write; | |
344 | if (write) | |
345 | return write(file, buf, count, ppos); | |
346 | return -EIO; | |
347 | } | |
348 | ||
866ad9a7 AV |
349 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
350 | { | |
866ad9a7 AV |
351 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
352 | ssize_t rv = -EIO; | |
9af27b28 | 353 | |
d919b33d AD |
354 | if (pde_is_permanent(pde)) { |
355 | return pde_write(pde, file, buf, count, ppos); | |
356 | } else if (use_pde(pde)) { | |
357 | rv = pde_write(pde, file, buf, count, ppos); | |
866ad9a7 AV |
358 | unuse_pde(pde); |
359 | } | |
786d7e16 AD |
360 | return rv; |
361 | } | |
362 | ||
d919b33d AD |
363 | static __poll_t pde_poll(struct proc_dir_entry *pde, struct file *file, struct poll_table_struct *pts) |
364 | { | |
365 | typeof_member(struct proc_ops, proc_poll) poll; | |
366 | ||
367 | poll = pde->proc_ops->proc_poll; | |
368 | if (poll) | |
369 | return poll(file, pts); | |
370 | return DEFAULT_POLLMASK; | |
371 | } | |
372 | ||
076ccb76 | 373 | static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts) |
786d7e16 | 374 | { |
496ad9aa | 375 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
e6c8adca | 376 | __poll_t rv = DEFAULT_POLLMASK; |
9af27b28 | 377 | |
d919b33d AD |
378 | if (pde_is_permanent(pde)) { |
379 | return pde_poll(pde, file, pts); | |
380 | } else if (use_pde(pde)) { | |
381 | rv = pde_poll(pde, file, pts); | |
866ad9a7 | 382 | unuse_pde(pde); |
786d7e16 | 383 | } |
786d7e16 AD |
384 | return rv; |
385 | } | |
386 | ||
d919b33d AD |
387 | static long pde_ioctl(struct proc_dir_entry *pde, struct file *file, unsigned int cmd, unsigned long arg) |
388 | { | |
389 | typeof_member(struct proc_ops, proc_ioctl) ioctl; | |
390 | ||
391 | ioctl = pde->proc_ops->proc_ioctl; | |
392 | if (ioctl) | |
393 | return ioctl(file, cmd, arg); | |
394 | return -ENOTTY; | |
395 | } | |
396 | ||
786d7e16 AD |
397 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
398 | { | |
496ad9aa | 399 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 400 | long rv = -ENOTTY; |
9af27b28 | 401 | |
d919b33d AD |
402 | if (pde_is_permanent(pde)) { |
403 | return pde_ioctl(pde, file, cmd, arg); | |
404 | } else if (use_pde(pde)) { | |
405 | rv = pde_ioctl(pde, file, cmd, arg); | |
866ad9a7 | 406 | unuse_pde(pde); |
786d7e16 | 407 | } |
786d7e16 AD |
408 | return rv; |
409 | } | |
410 | ||
411 | #ifdef CONFIG_COMPAT | |
d919b33d AD |
412 | static long pde_compat_ioctl(struct proc_dir_entry *pde, struct file *file, unsigned int cmd, unsigned long arg) |
413 | { | |
414 | typeof_member(struct proc_ops, proc_compat_ioctl) compat_ioctl; | |
415 | ||
416 | compat_ioctl = pde->proc_ops->proc_compat_ioctl; | |
417 | if (compat_ioctl) | |
418 | return compat_ioctl(file, cmd, arg); | |
419 | return -ENOTTY; | |
420 | } | |
421 | ||
786d7e16 AD |
422 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
423 | { | |
496ad9aa | 424 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 425 | long rv = -ENOTTY; |
d919b33d AD |
426 | if (pde_is_permanent(pde)) { |
427 | return pde_compat_ioctl(pde, file, cmd, arg); | |
428 | } else if (use_pde(pde)) { | |
429 | rv = pde_compat_ioctl(pde, file, cmd, arg); | |
866ad9a7 | 430 | unuse_pde(pde); |
786d7e16 | 431 | } |
786d7e16 AD |
432 | return rv; |
433 | } | |
434 | #endif | |
435 | ||
d919b33d AD |
436 | static int pde_mmap(struct proc_dir_entry *pde, struct file *file, struct vm_area_struct *vma) |
437 | { | |
438 | typeof_member(struct proc_ops, proc_mmap) mmap; | |
439 | ||
440 | mmap = pde->proc_ops->proc_mmap; | |
441 | if (mmap) | |
442 | return mmap(file, vma); | |
443 | return -EIO; | |
444 | } | |
445 | ||
786d7e16 AD |
446 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) |
447 | { | |
496ad9aa | 448 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 449 | int rv = -EIO; |
9af27b28 | 450 | |
d919b33d AD |
451 | if (pde_is_permanent(pde)) { |
452 | return pde_mmap(pde, file, vma); | |
453 | } else if (use_pde(pde)) { | |
454 | rv = pde_mmap(pde, file, vma); | |
866ad9a7 | 455 | unuse_pde(pde); |
786d7e16 | 456 | } |
786d7e16 AD |
457 | return rv; |
458 | } | |
459 | ||
5721cf84 | 460 | static unsigned long |
d919b33d | 461 | pde_get_unmapped_area(struct proc_dir_entry *pde, struct file *file, unsigned long orig_addr, |
5721cf84 HD |
462 | unsigned long len, unsigned long pgoff, |
463 | unsigned long flags) | |
c4fe2448 | 464 | { |
d919b33d | 465 | typeof_member(struct proc_ops, proc_get_unmapped_area) get_area; |
ae5758a1 | 466 | |
d919b33d | 467 | get_area = pde->proc_ops->proc_get_unmapped_area; |
fad1a86e | 468 | #ifdef CONFIG_MMU |
d919b33d AD |
469 | if (!get_area) |
470 | get_area = current->mm->get_unmapped_area; | |
fad1a86e | 471 | #endif |
d919b33d AD |
472 | if (get_area) |
473 | return get_area(file, orig_addr, len, pgoff, flags); | |
474 | return orig_addr; | |
475 | } | |
476 | ||
477 | static unsigned long | |
478 | proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, | |
479 | unsigned long len, unsigned long pgoff, | |
480 | unsigned long flags) | |
481 | { | |
482 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
483 | unsigned long rv = -EIO; | |
ae5758a1 | 484 | |
d919b33d AD |
485 | if (pde_is_permanent(pde)) { |
486 | return pde_get_unmapped_area(pde, file, orig_addr, len, pgoff, flags); | |
487 | } else if (use_pde(pde)) { | |
488 | rv = pde_get_unmapped_area(pde, file, orig_addr, len, pgoff, flags); | |
c4fe2448 AD |
489 | unuse_pde(pde); |
490 | } | |
491 | return rv; | |
492 | } | |
493 | ||
786d7e16 AD |
494 | static int proc_reg_open(struct inode *inode, struct file *file) |
495 | { | |
6814ef2d | 496 | struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb); |
786d7e16 AD |
497 | struct proc_dir_entry *pde = PDE(inode); |
498 | int rv = 0; | |
d56c0d45 AD |
499 | typeof_member(struct proc_ops, proc_open) open; |
500 | typeof_member(struct proc_ops, proc_release) release; | |
881adb85 AD |
501 | struct pde_opener *pdeo; |
502 | ||
d919b33d AD |
503 | if (pde_is_permanent(pde)) { |
504 | open = pde->proc_ops->proc_open; | |
505 | if (open) | |
506 | rv = open(inode, file); | |
507 | return rv; | |
508 | } | |
509 | ||
6814ef2d AG |
510 | if (fs_info->pidonly == PROC_PIDONLY_ON) |
511 | return -ENOENT; | |
512 | ||
881adb85 | 513 | /* |
492b2da6 AD |
514 | * Ensure that |
515 | * 1) PDE's ->release hook will be called no matter what | |
516 | * either normally by close()/->release, or forcefully by | |
517 | * rmmod/remove_proc_entry. | |
518 | * | |
519 | * 2) rmmod isn't blocked by opening file in /proc and sitting on | |
520 | * the descriptor (including "rmmod foo </proc/foo" scenario). | |
881adb85 | 521 | * |
492b2da6 | 522 | * Save every "struct file" with custom ->release hook. |
881adb85 | 523 | */ |
e7a6e291 | 524 | if (!use_pde(pde)) |
d2857e79 | 525 | return -ENOENT; |
e7a6e291 | 526 | |
d56c0d45 | 527 | release = pde->proc_ops->proc_release; |
e7a6e291 | 528 | if (release) { |
195b8cf0 | 529 | pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL); |
e7a6e291 AD |
530 | if (!pdeo) { |
531 | rv = -ENOMEM; | |
532 | goto out_unuse; | |
533 | } | |
534 | } | |
786d7e16 | 535 | |
d56c0d45 | 536 | open = pde->proc_ops->proc_open; |
786d7e16 AD |
537 | if (open) |
538 | rv = open(inode, file); | |
539 | ||
e7a6e291 AD |
540 | if (release) { |
541 | if (rv == 0) { | |
542 | /* To know what to release. */ | |
543 | pdeo->file = file; | |
544 | pdeo->closing = false; | |
545 | pdeo->c = NULL; | |
546 | spin_lock(&pde->pde_unload_lock); | |
547 | list_add(&pdeo->lh, &pde->pde_openers); | |
548 | spin_unlock(&pde->pde_unload_lock); | |
549 | } else | |
195b8cf0 | 550 | kmem_cache_free(pde_opener_cache, pdeo); |
e7a6e291 | 551 | } |
05c0ae21 | 552 | |
e7a6e291 | 553 | out_unuse: |
05c0ae21 | 554 | unuse_pde(pde); |
786d7e16 AD |
555 | return rv; |
556 | } | |
557 | ||
558 | static int proc_reg_release(struct inode *inode, struct file *file) | |
559 | { | |
560 | struct proc_dir_entry *pde = PDE(inode); | |
881adb85 | 561 | struct pde_opener *pdeo; |
d919b33d AD |
562 | |
563 | if (pde_is_permanent(pde)) { | |
564 | typeof_member(struct proc_ops, proc_release) release; | |
565 | ||
566 | release = pde->proc_ops->proc_release; | |
567 | if (release) { | |
568 | return release(inode, file); | |
569 | } | |
570 | return 0; | |
571 | } | |
572 | ||
786d7e16 | 573 | spin_lock(&pde->pde_unload_lock); |
ca469f35 AV |
574 | list_for_each_entry(pdeo, &pde->pde_openers, lh) { |
575 | if (pdeo->file == file) { | |
576 | close_pdeo(pde, pdeo); | |
2f897424 | 577 | return 0; |
ca469f35 | 578 | } |
881adb85 | 579 | } |
786d7e16 | 580 | spin_unlock(&pde->pde_unload_lock); |
ca469f35 | 581 | return 0; |
786d7e16 AD |
582 | } |
583 | ||
584 | static const struct file_operations proc_reg_file_ops = { | |
585 | .llseek = proc_reg_llseek, | |
586 | .read = proc_reg_read, | |
587 | .write = proc_reg_write, | |
588 | .poll = proc_reg_poll, | |
589 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
786d7e16 | 590 | .mmap = proc_reg_mmap, |
c4fe2448 | 591 | .get_unmapped_area = proc_reg_get_unmapped_area, |
786d7e16 AD |
592 | .open = proc_reg_open, |
593 | .release = proc_reg_release, | |
594 | }; | |
595 | ||
fd5a13f4 CH |
596 | static const struct file_operations proc_iter_file_ops = { |
597 | .llseek = proc_reg_llseek, | |
598 | .read_iter = proc_reg_read_iter, | |
599 | .write = proc_reg_write, | |
fe33850f | 600 | .splice_read = generic_file_splice_read, |
fd5a13f4 CH |
601 | .poll = proc_reg_poll, |
602 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
603 | .mmap = proc_reg_mmap, | |
604 | .get_unmapped_area = proc_reg_get_unmapped_area, | |
605 | .open = proc_reg_open, | |
606 | .release = proc_reg_release, | |
607 | }; | |
608 | ||
778f3dd5 | 609 | #ifdef CONFIG_COMPAT |
906146f4 | 610 | static const struct file_operations proc_reg_file_ops_compat = { |
778f3dd5 DM |
611 | .llseek = proc_reg_llseek, |
612 | .read = proc_reg_read, | |
613 | .write = proc_reg_write, | |
614 | .poll = proc_reg_poll, | |
615 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
906146f4 | 616 | .compat_ioctl = proc_reg_compat_ioctl, |
778f3dd5 | 617 | .mmap = proc_reg_mmap, |
c4fe2448 | 618 | .get_unmapped_area = proc_reg_get_unmapped_area, |
778f3dd5 DM |
619 | .open = proc_reg_open, |
620 | .release = proc_reg_release, | |
621 | }; | |
fd5a13f4 CH |
622 | |
623 | static const struct file_operations proc_iter_file_ops_compat = { | |
624 | .llseek = proc_reg_llseek, | |
625 | .read_iter = proc_reg_read_iter, | |
fe33850f | 626 | .splice_read = generic_file_splice_read, |
fd5a13f4 CH |
627 | .write = proc_reg_write, |
628 | .poll = proc_reg_poll, | |
629 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
630 | .compat_ioctl = proc_reg_compat_ioctl, | |
631 | .mmap = proc_reg_mmap, | |
632 | .get_unmapped_area = proc_reg_get_unmapped_area, | |
633 | .open = proc_reg_open, | |
634 | .release = proc_reg_release, | |
635 | }; | |
778f3dd5 DM |
636 | #endif |
637 | ||
fceef393 AV |
638 | static void proc_put_link(void *p) |
639 | { | |
640 | unuse_pde(p); | |
641 | } | |
642 | ||
6b255391 | 643 | static const char *proc_get_link(struct dentry *dentry, |
fceef393 AV |
644 | struct inode *inode, |
645 | struct delayed_call *done) | |
7e0e953b | 646 | { |
6b255391 | 647 | struct proc_dir_entry *pde = PDE(inode); |
15b158b4 | 648 | if (!use_pde(pde)) |
7e0e953b | 649 | return ERR_PTR(-EINVAL); |
fceef393 | 650 | set_delayed_call(done, proc_put_link, pde); |
680baacb | 651 | return pde->data; |
7e0e953b AV |
652 | } |
653 | ||
7e0e953b | 654 | const struct inode_operations proc_link_inode_operations = { |
6b255391 | 655 | .get_link = proc_get_link, |
7e0e953b AV |
656 | }; |
657 | ||
6d1b6e4e | 658 | struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) |
1da177e4 | 659 | { |
ef1548ad | 660 | struct inode *inode = new_inode(sb); |
1da177e4 | 661 | |
f6ef7b7b CH |
662 | if (!inode) { |
663 | pde_put(de); | |
664 | return NULL; | |
665 | } | |
666 | ||
667 | inode->i_ino = de->low_ino; | |
668 | inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode); | |
669 | PROC_I(inode)->pde = de; | |
670 | if (is_empty_pde(de)) { | |
671 | make_empty_dir_inode(inode); | |
672 | return inode; | |
673 | } | |
674 | ||
675 | if (de->mode) { | |
676 | inode->i_mode = de->mode; | |
677 | inode->i_uid = de->uid; | |
678 | inode->i_gid = de->gid; | |
679 | } | |
680 | if (de->size) | |
681 | inode->i_size = de->size; | |
682 | if (de->nlink) | |
683 | set_nlink(inode, de->nlink); | |
684 | ||
685 | if (S_ISREG(inode->i_mode)) { | |
686 | inode->i_op = de->proc_iops; | |
fd5a13f4 CH |
687 | if (de->proc_ops->proc_read_iter) |
688 | inode->i_fop = &proc_iter_file_ops; | |
689 | else | |
690 | inode->i_fop = &proc_reg_file_ops; | |
778f3dd5 | 691 | #ifdef CONFIG_COMPAT |
fd5a13f4 CH |
692 | if (de->proc_ops->proc_compat_ioctl) { |
693 | if (de->proc_ops->proc_read_iter) | |
694 | inode->i_fop = &proc_iter_file_ops_compat; | |
695 | else | |
696 | inode->i_fop = &proc_reg_file_ops_compat; | |
697 | } | |
d56c0d45 | 698 | #endif |
f6ef7b7b CH |
699 | } else if (S_ISDIR(inode->i_mode)) { |
700 | inode->i_op = de->proc_iops; | |
701 | inode->i_fop = de->proc_dir_ops; | |
702 | } else if (S_ISLNK(inode->i_mode)) { | |
703 | inode->i_op = de->proc_iops; | |
704 | inode->i_fop = NULL; | |
705 | } else { | |
706 | BUG(); | |
707 | } | |
1da177e4 | 708 | return inode; |
d3d009cb | 709 | } |