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 | |
fee781e6 | 29 | #include "internal.h" |
1da177e4 | 30 | |
8267952b | 31 | static void proc_evict_inode(struct inode *inode) |
1da177e4 | 32 | { |
dfef6dcd | 33 | struct ctl_table_header *head; |
71448011 | 34 | struct proc_inode *ei = PROC_I(inode); |
1da177e4 | 35 | |
91b0abe3 | 36 | truncate_inode_pages_final(&inode->i_data); |
dbd5768f | 37 | clear_inode(inode); |
fef26658 | 38 | |
99f89551 | 39 | /* Stop tracking associated processes */ |
47458802 | 40 | if (ei->pid) |
7bc3e6e5 | 41 | proc_pid_evict_inode(ei); |
d6cffbbe | 42 | |
71448011 | 43 | head = ei->sysctl; |
dfef6dcd | 44 | if (head) { |
71448011 | 45 | RCU_INIT_POINTER(ei->sysctl, NULL); |
d6cffbbe | 46 | proc_sys_evict_inode(inode, head); |
dfef6dcd | 47 | } |
1da177e4 LT |
48 | } |
49 | ||
efb1a57d | 50 | static struct kmem_cache *proc_inode_cachep __ro_after_init; |
195b8cf0 | 51 | static struct kmem_cache *pde_opener_cache __ro_after_init; |
1da177e4 LT |
52 | |
53 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
54 | { | |
55 | struct proc_inode *ei; | |
1da177e4 | 56 | |
fd60b288 | 57 | ei = alloc_inode_sb(sb, proc_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
58 | if (!ei) |
59 | return NULL; | |
13b41b09 | 60 | ei->pid = NULL; |
aed7a6c4 | 61 | ei->fd = 0; |
1da177e4 LT |
62 | ei->op.proc_get_link = NULL; |
63 | ei->pde = NULL; | |
9043476f AV |
64 | ei->sysctl = NULL; |
65 | ei->sysctl_entry = NULL; | |
0afa5ca8 | 66 | INIT_HLIST_NODE(&ei->sibling_inodes); |
3d3d35b1 | 67 | ei->ns_ops = NULL; |
230f72e9 | 68 | return &ei->vfs_inode; |
1da177e4 LT |
69 | } |
70 | ||
4aa6b55c | 71 | static void proc_free_inode(struct inode *inode) |
1da177e4 | 72 | { |
47458802 AV |
73 | struct proc_inode *ei = PROC_I(inode); |
74 | ||
75 | if (ei->pid) | |
76 | put_pid(ei->pid); | |
77 | /* Let go of any associated proc directory entry */ | |
78 | if (ei->pde) | |
79 | pde_put(ei->pde); | |
1da177e4 LT |
80 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); |
81 | } | |
82 | ||
51cc5068 | 83 | static void init_once(void *foo) |
1da177e4 LT |
84 | { |
85 | struct proc_inode *ei = (struct proc_inode *) foo; | |
86 | ||
a35afb83 | 87 | inode_init_once(&ei->vfs_inode); |
1da177e4 | 88 | } |
20c2df83 | 89 | |
195b8cf0 | 90 | void __init proc_init_kmemcache(void) |
1da177e4 LT |
91 | { |
92 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
93 | sizeof(struct proc_inode), | |
fffb60f9 | 94 | 0, (SLAB_RECLAIM_ACCOUNT| |
c762b979 | 95 | SLAB_ACCOUNT| |
5d097056 | 96 | SLAB_PANIC), |
20c2df83 | 97 | init_once); |
195b8cf0 AD |
98 | pde_opener_cache = |
99 | kmem_cache_create("pde_opener", sizeof(struct pde_opener), 0, | |
2acddbe8 | 100 | SLAB_ACCOUNT|SLAB_PANIC, NULL); |
b4884f23 | 101 | proc_dir_entry_cache = kmem_cache_create_usercopy( |
2d6e4e82 AD |
102 | "proc_dir_entry", SIZEOF_PDE, 0, SLAB_PANIC, |
103 | offsetof(struct proc_dir_entry, inline_name), | |
104 | SIZEOF_PDE_INLINE_NAME, NULL); | |
105 | BUILD_BUG_ON(sizeof(struct proc_dir_entry) >= SIZEOF_PDE); | |
1da177e4 LT |
106 | } |
107 | ||
f90f3caf | 108 | void proc_invalidate_siblings_dcache(struct hlist_head *inodes, spinlock_t *lock) |
26dbc60f | 109 | { |
26dbc60f | 110 | struct hlist_node *node; |
080f6276 | 111 | struct super_block *old_sb = NULL; |
26dbc60f EB |
112 | |
113 | rcu_read_lock(); | |
ead5a727 AD |
114 | while ((node = hlist_first_rcu(inodes))) { |
115 | struct proc_inode *ei = hlist_entry(node, struct proc_inode, sibling_inodes); | |
080f6276 | 116 | struct super_block *sb; |
ead5a727 AD |
117 | struct inode *inode; |
118 | ||
26dbc60f EB |
119 | spin_lock(lock); |
120 | hlist_del_init_rcu(&ei->sibling_inodes); | |
121 | spin_unlock(lock); | |
122 | ||
123 | inode = &ei->vfs_inode; | |
124 | sb = inode->i_sb; | |
080f6276 | 125 | if ((sb != old_sb) && !atomic_inc_not_zero(&sb->s_active)) |
26dbc60f EB |
126 | continue; |
127 | inode = igrab(inode); | |
128 | rcu_read_unlock(); | |
080f6276 EB |
129 | if (sb != old_sb) { |
130 | if (old_sb) | |
131 | deactivate_super(old_sb); | |
132 | old_sb = sb; | |
133 | } | |
26dbc60f | 134 | if (unlikely(!inode)) { |
26dbc60f EB |
135 | rcu_read_lock(); |
136 | continue; | |
137 | } | |
138 | ||
f90f3caf EB |
139 | if (S_ISDIR(inode->i_mode)) { |
140 | struct dentry *dir = d_find_any_alias(inode); | |
141 | if (dir) { | |
142 | d_invalidate(dir); | |
143 | dput(dir); | |
144 | } | |
145 | } else { | |
146 | struct dentry *dentry; | |
147 | while ((dentry = d_find_alias(inode))) { | |
148 | d_invalidate(dentry); | |
149 | dput(dentry); | |
150 | } | |
151 | } | |
26dbc60f | 152 | iput(inode); |
26dbc60f EB |
153 | |
154 | rcu_read_lock(); | |
155 | } | |
156 | rcu_read_unlock(); | |
080f6276 EB |
157 | if (old_sb) |
158 | deactivate_super(old_sb); | |
26dbc60f EB |
159 | } |
160 | ||
e61bb8b3 | 161 | static inline const char *hidepid2str(enum proc_hidepid v) |
1c6c4d11 AG |
162 | { |
163 | switch (v) { | |
164 | case HIDEPID_OFF: return "off"; | |
165 | case HIDEPID_NO_ACCESS: return "noaccess"; | |
166 | case HIDEPID_INVISIBLE: return "invisible"; | |
167 | case HIDEPID_NOT_PTRACEABLE: return "ptraceable"; | |
168 | } | |
169 | WARN_ONCE(1, "bad hide_pid value: %d\n", v); | |
170 | return "unknown"; | |
171 | } | |
172 | ||
97412950 VK |
173 | static int proc_show_options(struct seq_file *seq, struct dentry *root) |
174 | { | |
fa10fed3 | 175 | struct proc_fs_info *fs_info = proc_sb_info(root->d_sb); |
0499680a | 176 | |
fa10fed3 AG |
177 | if (!gid_eq(fs_info->pid_gid, GLOBAL_ROOT_GID)) |
178 | seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, fs_info->pid_gid)); | |
179 | if (fs_info->hide_pid != HIDEPID_OFF) | |
1c6c4d11 | 180 | seq_printf(seq, ",hidepid=%s", hidepid2str(fs_info->hide_pid)); |
6814ef2d AG |
181 | if (fs_info->pidonly != PROC_PIDONLY_OFF) |
182 | seq_printf(seq, ",subset=pid"); | |
0499680a | 183 | |
97412950 VK |
184 | return 0; |
185 | } | |
186 | ||
60a3c3a5 | 187 | const struct super_operations proc_sops = { |
1da177e4 | 188 | .alloc_inode = proc_alloc_inode, |
4aa6b55c | 189 | .free_inode = proc_free_inode, |
1da177e4 | 190 | .drop_inode = generic_delete_inode, |
8267952b | 191 | .evict_inode = proc_evict_inode, |
1da177e4 | 192 | .statfs = simple_statfs, |
97412950 | 193 | .show_options = proc_show_options, |
1da177e4 LT |
194 | }; |
195 | ||
866ad9a7 AV |
196 | enum {BIAS = -1U<<31}; |
197 | ||
198 | static inline int use_pde(struct proc_dir_entry *pde) | |
199 | { | |
15b158b4 | 200 | return likely(atomic_inc_unless_negative(&pde->in_use)); |
881adb85 AD |
201 | } |
202 | ||
866ad9a7 | 203 | static void unuse_pde(struct proc_dir_entry *pde) |
881adb85 | 204 | { |
15b158b4 | 205 | if (unlikely(atomic_dec_return(&pde->in_use) == BIAS)) |
05c0ae21 | 206 | complete(pde->pde_unload_completion); |
786d7e16 AD |
207 | } |
208 | ||
ed8fb78d AD |
209 | /* |
210 | * At most 2 contexts can enter this function: the one doing the last | |
211 | * close on the descriptor and whoever is deleting PDE itself. | |
212 | * | |
213 | * First to enter calls ->proc_release hook and signals its completion | |
214 | * to the second one which waits and then does nothing. | |
215 | * | |
216 | * PDE is locked on entry, unlocked on exit. | |
217 | */ | |
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. | |
492b2da6 | 227 | */ |
05c0ae21 | 228 | if (pdeo->closing) { |
ca469f35 | 229 | /* somebody else is doing that, just wait */ |
05c0ae21 AV |
230 | DECLARE_COMPLETION_ONSTACK(c); |
231 | pdeo->c = &c; | |
ca469f35 | 232 | spin_unlock(&pde->pde_unload_lock); |
05c0ae21 | 233 | wait_for_completion(&c); |
ca469f35 AV |
234 | } else { |
235 | struct file *file; | |
2f897424 AD |
236 | struct completion *c; |
237 | ||
f5887c71 | 238 | pdeo->closing = true; |
ca469f35 | 239 | spin_unlock(&pde->pde_unload_lock); |
ed8fb78d | 240 | |
ca469f35 | 241 | file = pdeo->file; |
d56c0d45 | 242 | pde->proc_ops->proc_release(file_inode(file), file); |
ed8fb78d | 243 | |
ca469f35 | 244 | spin_lock(&pde->pde_unload_lock); |
ed8fb78d | 245 | /* Strictly after ->proc_release, see above. */ |
06a0c417 | 246 | list_del(&pdeo->lh); |
2f897424 AD |
247 | c = pdeo->c; |
248 | spin_unlock(&pde->pde_unload_lock); | |
249 | if (unlikely(c)) | |
250 | complete(c); | |
195b8cf0 | 251 | kmem_cache_free(pde_opener_cache, pdeo); |
05c0ae21 | 252 | } |
ca469f35 AV |
253 | } |
254 | ||
866ad9a7 | 255 | void proc_entry_rundown(struct proc_dir_entry *de) |
786d7e16 | 256 | { |
05c0ae21 | 257 | DECLARE_COMPLETION_ONSTACK(c); |
866ad9a7 | 258 | /* Wait until all existing callers into module are done. */ |
05c0ae21 AV |
259 | de->pde_unload_completion = &c; |
260 | if (atomic_add_return(BIAS, &de->in_use) != BIAS) | |
261 | wait_for_completion(&c); | |
786d7e16 | 262 | |
492b2da6 AD |
263 | /* ->pde_openers list can't grow from now on. */ |
264 | ||
05c0ae21 | 265 | spin_lock(&de->pde_unload_lock); |
866ad9a7 AV |
266 | while (!list_empty(&de->pde_openers)) { |
267 | struct pde_opener *pdeo; | |
866ad9a7 | 268 | pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); |
ca469f35 | 269 | close_pdeo(de, pdeo); |
2f897424 | 270 | spin_lock(&de->pde_unload_lock); |
866ad9a7 AV |
271 | } |
272 | spin_unlock(&de->pde_unload_lock); | |
786d7e16 AD |
273 | } |
274 | ||
866ad9a7 AV |
275 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) |
276 | { | |
277 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
278 | loff_t rv = -EINVAL; | |
9af27b28 | 279 | |
d919b33d | 280 | if (pde_is_permanent(pde)) { |
d4455fac | 281 | return pde->proc_ops->proc_lseek(file, offset, whence); |
d919b33d | 282 | } else if (use_pde(pde)) { |
d4455fac | 283 | rv = pde->proc_ops->proc_lseek(file, offset, whence); |
866ad9a7 AV |
284 | unuse_pde(pde); |
285 | } | |
786d7e16 AD |
286 | return rv; |
287 | } | |
288 | ||
fd5a13f4 CH |
289 | static ssize_t proc_reg_read_iter(struct kiocb *iocb, struct iov_iter *iter) |
290 | { | |
291 | struct proc_dir_entry *pde = PDE(file_inode(iocb->ki_filp)); | |
292 | ssize_t ret; | |
293 | ||
294 | if (pde_is_permanent(pde)) | |
295 | return pde->proc_ops->proc_read_iter(iocb, iter); | |
296 | ||
297 | if (!use_pde(pde)) | |
298 | return -EIO; | |
299 | ret = pde->proc_ops->proc_read_iter(iocb, iter); | |
300 | unuse_pde(pde); | |
301 | return ret; | |
302 | } | |
303 | ||
d919b33d AD |
304 | static ssize_t pde_read(struct proc_dir_entry *pde, struct file *file, char __user *buf, size_t count, loff_t *ppos) |
305 | { | |
306 | typeof_member(struct proc_ops, proc_read) read; | |
307 | ||
308 | read = pde->proc_ops->proc_read; | |
309 | if (read) | |
310 | return read(file, buf, count, ppos); | |
311 | return -EIO; | |
312 | } | |
313 | ||
866ad9a7 | 314 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
786d7e16 | 315 | { |
496ad9aa | 316 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 317 | ssize_t rv = -EIO; |
9af27b28 | 318 | |
d919b33d AD |
319 | if (pde_is_permanent(pde)) { |
320 | return pde_read(pde, file, buf, count, ppos); | |
321 | } else if (use_pde(pde)) { | |
322 | rv = pde_read(pde, file, buf, count, ppos); | |
866ad9a7 | 323 | unuse_pde(pde); |
786d7e16 | 324 | } |
866ad9a7 AV |
325 | return rv; |
326 | } | |
786d7e16 | 327 | |
d919b33d AD |
328 | static ssize_t pde_write(struct proc_dir_entry *pde, struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
329 | { | |
330 | typeof_member(struct proc_ops, proc_write) write; | |
331 | ||
332 | write = pde->proc_ops->proc_write; | |
333 | if (write) | |
334 | return write(file, buf, count, ppos); | |
335 | return -EIO; | |
336 | } | |
337 | ||
866ad9a7 AV |
338 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
339 | { | |
866ad9a7 AV |
340 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
341 | ssize_t rv = -EIO; | |
9af27b28 | 342 | |
d919b33d AD |
343 | if (pde_is_permanent(pde)) { |
344 | return pde_write(pde, file, buf, count, ppos); | |
345 | } else if (use_pde(pde)) { | |
346 | rv = pde_write(pde, file, buf, count, ppos); | |
866ad9a7 AV |
347 | unuse_pde(pde); |
348 | } | |
786d7e16 AD |
349 | return rv; |
350 | } | |
351 | ||
d919b33d AD |
352 | static __poll_t pde_poll(struct proc_dir_entry *pde, struct file *file, struct poll_table_struct *pts) |
353 | { | |
354 | typeof_member(struct proc_ops, proc_poll) poll; | |
355 | ||
356 | poll = pde->proc_ops->proc_poll; | |
357 | if (poll) | |
358 | return poll(file, pts); | |
359 | return DEFAULT_POLLMASK; | |
360 | } | |
361 | ||
076ccb76 | 362 | static __poll_t proc_reg_poll(struct file *file, struct poll_table_struct *pts) |
786d7e16 | 363 | { |
496ad9aa | 364 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
e6c8adca | 365 | __poll_t rv = DEFAULT_POLLMASK; |
9af27b28 | 366 | |
d919b33d AD |
367 | if (pde_is_permanent(pde)) { |
368 | return pde_poll(pde, file, pts); | |
369 | } else if (use_pde(pde)) { | |
370 | rv = pde_poll(pde, file, pts); | |
866ad9a7 | 371 | unuse_pde(pde); |
786d7e16 | 372 | } |
786d7e16 AD |
373 | return rv; |
374 | } | |
375 | ||
d919b33d AD |
376 | static long pde_ioctl(struct proc_dir_entry *pde, struct file *file, unsigned int cmd, unsigned long arg) |
377 | { | |
378 | typeof_member(struct proc_ops, proc_ioctl) ioctl; | |
379 | ||
380 | ioctl = pde->proc_ops->proc_ioctl; | |
381 | if (ioctl) | |
382 | return ioctl(file, cmd, arg); | |
383 | return -ENOTTY; | |
384 | } | |
385 | ||
786d7e16 AD |
386 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
387 | { | |
496ad9aa | 388 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 389 | long rv = -ENOTTY; |
9af27b28 | 390 | |
d919b33d AD |
391 | if (pde_is_permanent(pde)) { |
392 | return pde_ioctl(pde, file, cmd, arg); | |
393 | } else if (use_pde(pde)) { | |
394 | rv = pde_ioctl(pde, file, cmd, arg); | |
866ad9a7 | 395 | unuse_pde(pde); |
786d7e16 | 396 | } |
786d7e16 AD |
397 | return rv; |
398 | } | |
399 | ||
400 | #ifdef CONFIG_COMPAT | |
d919b33d AD |
401 | static long pde_compat_ioctl(struct proc_dir_entry *pde, struct file *file, unsigned int cmd, unsigned long arg) |
402 | { | |
403 | typeof_member(struct proc_ops, proc_compat_ioctl) compat_ioctl; | |
404 | ||
405 | compat_ioctl = pde->proc_ops->proc_compat_ioctl; | |
406 | if (compat_ioctl) | |
407 | return compat_ioctl(file, cmd, arg); | |
408 | return -ENOTTY; | |
409 | } | |
410 | ||
786d7e16 AD |
411 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
412 | { | |
496ad9aa | 413 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 414 | long rv = -ENOTTY; |
d919b33d AD |
415 | if (pde_is_permanent(pde)) { |
416 | return pde_compat_ioctl(pde, file, cmd, arg); | |
417 | } else if (use_pde(pde)) { | |
418 | rv = pde_compat_ioctl(pde, file, cmd, arg); | |
866ad9a7 | 419 | unuse_pde(pde); |
786d7e16 | 420 | } |
786d7e16 AD |
421 | return rv; |
422 | } | |
423 | #endif | |
424 | ||
d919b33d AD |
425 | static int pde_mmap(struct proc_dir_entry *pde, struct file *file, struct vm_area_struct *vma) |
426 | { | |
427 | typeof_member(struct proc_ops, proc_mmap) mmap; | |
428 | ||
429 | mmap = pde->proc_ops->proc_mmap; | |
430 | if (mmap) | |
431 | return mmap(file, vma); | |
432 | return -EIO; | |
433 | } | |
434 | ||
786d7e16 AD |
435 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) |
436 | { | |
496ad9aa | 437 | struct proc_dir_entry *pde = PDE(file_inode(file)); |
786d7e16 | 438 | int rv = -EIO; |
9af27b28 | 439 | |
d919b33d AD |
440 | if (pde_is_permanent(pde)) { |
441 | return pde_mmap(pde, file, vma); | |
442 | } else if (use_pde(pde)) { | |
443 | rv = pde_mmap(pde, file, vma); | |
866ad9a7 | 444 | unuse_pde(pde); |
786d7e16 | 445 | } |
786d7e16 AD |
446 | return rv; |
447 | } | |
448 | ||
5721cf84 | 449 | static unsigned long |
d919b33d | 450 | pde_get_unmapped_area(struct proc_dir_entry *pde, struct file *file, unsigned long orig_addr, |
5721cf84 HD |
451 | unsigned long len, unsigned long pgoff, |
452 | unsigned long flags) | |
c4fe2448 | 453 | { |
5def1e0f RE |
454 | if (pde->proc_ops->proc_get_unmapped_area) |
455 | return pde->proc_ops->proc_get_unmapped_area(file, orig_addr, len, pgoff, flags); | |
ae5758a1 | 456 | |
fad1a86e | 457 | #ifdef CONFIG_MMU |
529ce23a | 458 | return mm_get_unmapped_area(current->mm, file, orig_addr, len, pgoff, flags); |
fad1a86e | 459 | #endif |
529ce23a | 460 | |
d919b33d AD |
461 | return orig_addr; |
462 | } | |
463 | ||
464 | static unsigned long | |
465 | proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, | |
466 | unsigned long len, unsigned long pgoff, | |
467 | unsigned long flags) | |
468 | { | |
469 | struct proc_dir_entry *pde = PDE(file_inode(file)); | |
470 | unsigned long rv = -EIO; | |
ae5758a1 | 471 | |
d919b33d AD |
472 | if (pde_is_permanent(pde)) { |
473 | return pde_get_unmapped_area(pde, file, orig_addr, len, pgoff, flags); | |
474 | } else if (use_pde(pde)) { | |
475 | rv = pde_get_unmapped_area(pde, file, orig_addr, len, pgoff, flags); | |
c4fe2448 AD |
476 | unuse_pde(pde); |
477 | } | |
478 | return rv; | |
479 | } | |
480 | ||
786d7e16 AD |
481 | static int proc_reg_open(struct inode *inode, struct file *file) |
482 | { | |
483 | struct proc_dir_entry *pde = PDE(inode); | |
484 | int rv = 0; | |
d56c0d45 AD |
485 | typeof_member(struct proc_ops, proc_open) open; |
486 | typeof_member(struct proc_ops, proc_release) release; | |
881adb85 AD |
487 | struct pde_opener *pdeo; |
488 | ||
3f61631d AV |
489 | if (!pde->proc_ops->proc_lseek) |
490 | file->f_mode &= ~FMODE_LSEEK; | |
491 | ||
d919b33d AD |
492 | if (pde_is_permanent(pde)) { |
493 | open = pde->proc_ops->proc_open; | |
494 | if (open) | |
495 | rv = open(inode, file); | |
496 | return rv; | |
497 | } | |
498 | ||
881adb85 | 499 | /* |
492b2da6 AD |
500 | * Ensure that |
501 | * 1) PDE's ->release hook will be called no matter what | |
502 | * either normally by close()/->release, or forcefully by | |
503 | * rmmod/remove_proc_entry. | |
504 | * | |
505 | * 2) rmmod isn't blocked by opening file in /proc and sitting on | |
506 | * the descriptor (including "rmmod foo </proc/foo" scenario). | |
881adb85 | 507 | * |
492b2da6 | 508 | * Save every "struct file" with custom ->release hook. |
881adb85 | 509 | */ |
e7a6e291 | 510 | if (!use_pde(pde)) |
d2857e79 | 511 | return -ENOENT; |
e7a6e291 | 512 | |
d56c0d45 | 513 | release = pde->proc_ops->proc_release; |
e7a6e291 | 514 | if (release) { |
195b8cf0 | 515 | pdeo = kmem_cache_alloc(pde_opener_cache, GFP_KERNEL); |
e7a6e291 AD |
516 | if (!pdeo) { |
517 | rv = -ENOMEM; | |
518 | goto out_unuse; | |
519 | } | |
520 | } | |
786d7e16 | 521 | |
d56c0d45 | 522 | open = pde->proc_ops->proc_open; |
786d7e16 AD |
523 | if (open) |
524 | rv = open(inode, file); | |
525 | ||
e7a6e291 AD |
526 | if (release) { |
527 | if (rv == 0) { | |
528 | /* To know what to release. */ | |
529 | pdeo->file = file; | |
530 | pdeo->closing = false; | |
531 | pdeo->c = NULL; | |
532 | spin_lock(&pde->pde_unload_lock); | |
533 | list_add(&pdeo->lh, &pde->pde_openers); | |
534 | spin_unlock(&pde->pde_unload_lock); | |
535 | } else | |
195b8cf0 | 536 | kmem_cache_free(pde_opener_cache, pdeo); |
e7a6e291 | 537 | } |
05c0ae21 | 538 | |
e7a6e291 | 539 | out_unuse: |
05c0ae21 | 540 | unuse_pde(pde); |
786d7e16 AD |
541 | return rv; |
542 | } | |
543 | ||
544 | static int proc_reg_release(struct inode *inode, struct file *file) | |
545 | { | |
546 | struct proc_dir_entry *pde = PDE(inode); | |
881adb85 | 547 | struct pde_opener *pdeo; |
d919b33d AD |
548 | |
549 | if (pde_is_permanent(pde)) { | |
550 | typeof_member(struct proc_ops, proc_release) release; | |
551 | ||
552 | release = pde->proc_ops->proc_release; | |
553 | if (release) { | |
554 | return release(inode, file); | |
555 | } | |
556 | return 0; | |
557 | } | |
558 | ||
786d7e16 | 559 | spin_lock(&pde->pde_unload_lock); |
ca469f35 AV |
560 | list_for_each_entry(pdeo, &pde->pde_openers, lh) { |
561 | if (pdeo->file == file) { | |
562 | close_pdeo(pde, pdeo); | |
2f897424 | 563 | return 0; |
ca469f35 | 564 | } |
881adb85 | 565 | } |
786d7e16 | 566 | spin_unlock(&pde->pde_unload_lock); |
ca469f35 | 567 | return 0; |
786d7e16 AD |
568 | } |
569 | ||
570 | static const struct file_operations proc_reg_file_ops = { | |
571 | .llseek = proc_reg_llseek, | |
572 | .read = proc_reg_read, | |
573 | .write = proc_reg_write, | |
574 | .poll = proc_reg_poll, | |
575 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
786d7e16 | 576 | .mmap = proc_reg_mmap, |
c4fe2448 | 577 | .get_unmapped_area = proc_reg_get_unmapped_area, |
786d7e16 AD |
578 | .open = proc_reg_open, |
579 | .release = proc_reg_release, | |
580 | }; | |
581 | ||
fd5a13f4 CH |
582 | static const struct file_operations proc_iter_file_ops = { |
583 | .llseek = proc_reg_llseek, | |
584 | .read_iter = proc_reg_read_iter, | |
585 | .write = proc_reg_write, | |
b0072734 | 586 | .splice_read = copy_splice_read, |
fd5a13f4 CH |
587 | .poll = proc_reg_poll, |
588 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
589 | .mmap = proc_reg_mmap, | |
590 | .get_unmapped_area = proc_reg_get_unmapped_area, | |
591 | .open = proc_reg_open, | |
592 | .release = proc_reg_release, | |
593 | }; | |
594 | ||
778f3dd5 | 595 | #ifdef CONFIG_COMPAT |
906146f4 | 596 | static const struct file_operations proc_reg_file_ops_compat = { |
778f3dd5 DM |
597 | .llseek = proc_reg_llseek, |
598 | .read = proc_reg_read, | |
599 | .write = proc_reg_write, | |
600 | .poll = proc_reg_poll, | |
601 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
906146f4 | 602 | .compat_ioctl = proc_reg_compat_ioctl, |
778f3dd5 | 603 | .mmap = proc_reg_mmap, |
c4fe2448 | 604 | .get_unmapped_area = proc_reg_get_unmapped_area, |
778f3dd5 DM |
605 | .open = proc_reg_open, |
606 | .release = proc_reg_release, | |
607 | }; | |
fd5a13f4 CH |
608 | |
609 | static const struct file_operations proc_iter_file_ops_compat = { | |
610 | .llseek = proc_reg_llseek, | |
611 | .read_iter = proc_reg_read_iter, | |
b0072734 | 612 | .splice_read = copy_splice_read, |
fd5a13f4 CH |
613 | .write = proc_reg_write, |
614 | .poll = proc_reg_poll, | |
615 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
616 | .compat_ioctl = proc_reg_compat_ioctl, | |
617 | .mmap = proc_reg_mmap, | |
618 | .get_unmapped_area = proc_reg_get_unmapped_area, | |
619 | .open = proc_reg_open, | |
620 | .release = proc_reg_release, | |
621 | }; | |
778f3dd5 DM |
622 | #endif |
623 | ||
fceef393 AV |
624 | static void proc_put_link(void *p) |
625 | { | |
626 | unuse_pde(p); | |
627 | } | |
628 | ||
6b255391 | 629 | static const char *proc_get_link(struct dentry *dentry, |
fceef393 AV |
630 | struct inode *inode, |
631 | struct delayed_call *done) | |
7e0e953b | 632 | { |
6b255391 | 633 | struct proc_dir_entry *pde = PDE(inode); |
15b158b4 | 634 | if (!use_pde(pde)) |
7e0e953b | 635 | return ERR_PTR(-EINVAL); |
fceef393 | 636 | set_delayed_call(done, proc_put_link, pde); |
680baacb | 637 | return pde->data; |
7e0e953b AV |
638 | } |
639 | ||
7e0e953b | 640 | const struct inode_operations proc_link_inode_operations = { |
6b255391 | 641 | .get_link = proc_get_link, |
7e0e953b AV |
642 | }; |
643 | ||
6d1b6e4e | 644 | struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) |
1da177e4 | 645 | { |
ef1548ad | 646 | struct inode *inode = new_inode(sb); |
1da177e4 | 647 | |
f6ef7b7b CH |
648 | if (!inode) { |
649 | pde_put(de); | |
650 | return NULL; | |
651 | } | |
652 | ||
6dfbbae1 | 653 | inode->i_private = de->data; |
f6ef7b7b | 654 | inode->i_ino = de->low_ino; |
200d9421 | 655 | simple_inode_init_ts(inode); |
f6ef7b7b CH |
656 | PROC_I(inode)->pde = de; |
657 | if (is_empty_pde(de)) { | |
658 | make_empty_dir_inode(inode); | |
659 | return inode; | |
660 | } | |
661 | ||
662 | if (de->mode) { | |
663 | inode->i_mode = de->mode; | |
664 | inode->i_uid = de->uid; | |
665 | inode->i_gid = de->gid; | |
666 | } | |
667 | if (de->size) | |
668 | inode->i_size = de->size; | |
669 | if (de->nlink) | |
670 | set_nlink(inode, de->nlink); | |
671 | ||
672 | if (S_ISREG(inode->i_mode)) { | |
673 | inode->i_op = de->proc_iops; | |
fd5a13f4 CH |
674 | if (de->proc_ops->proc_read_iter) |
675 | inode->i_fop = &proc_iter_file_ops; | |
676 | else | |
677 | inode->i_fop = &proc_reg_file_ops; | |
778f3dd5 | 678 | #ifdef CONFIG_COMPAT |
fd5a13f4 CH |
679 | if (de->proc_ops->proc_compat_ioctl) { |
680 | if (de->proc_ops->proc_read_iter) | |
681 | inode->i_fop = &proc_iter_file_ops_compat; | |
682 | else | |
683 | inode->i_fop = &proc_reg_file_ops_compat; | |
684 | } | |
d56c0d45 | 685 | #endif |
f6ef7b7b CH |
686 | } else if (S_ISDIR(inode->i_mode)) { |
687 | inode->i_op = de->proc_iops; | |
688 | inode->i_fop = de->proc_dir_ops; | |
689 | } else if (S_ISLNK(inode->i_mode)) { | |
690 | inode->i_op = de->proc_iops; | |
691 | inode->i_fop = NULL; | |
692 | } else { | |
693 | BUG(); | |
694 | } | |
1da177e4 | 695 | return inode; |
d3d009cb | 696 | } |