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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * file.c - part of debugfs, a tiny little debug file system
4 *
5 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (C) 2004 IBM Inc.
7 *
8 * debugfs is for people to use instead of /proc or /sys.
9 * See Documentation/filesystems/ for more details.
10 */
11
12#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/seq_file.h>
15#include <linux/pagemap.h>
16#include <linux/debugfs.h>
17#include <linux/io.h>
18#include <linux/slab.h>
19#include <linux/atomic.h>
20#include <linux/device.h>
21#include <linux/poll.h>
22#include <linux/security.h>
23
24#include "internal.h"
25
26struct poll_table_struct;
27
28static ssize_t default_read_file(struct file *file, char __user *buf,
29 size_t count, loff_t *ppos)
30{
31 return 0;
32}
33
34static ssize_t default_write_file(struct file *file, const char __user *buf,
35 size_t count, loff_t *ppos)
36{
37 return count;
38}
39
40const struct file_operations debugfs_noop_file_operations = {
41 .read = default_read_file,
42 .write = default_write_file,
43 .open = simple_open,
44 .llseek = noop_llseek,
45};
46
47#define F_DENTRY(filp) ((filp)->f_path.dentry)
48
49const struct file_operations *debugfs_real_fops(const struct file *filp)
50{
51 struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
52
53 if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
54 /*
55 * Urgh, we've been called w/o a protecting
56 * debugfs_file_get().
57 */
58 WARN_ON(1);
59 return NULL;
60 }
61
62 return fsd->real_fops;
63}
64EXPORT_SYMBOL_GPL(debugfs_real_fops);
65
66/**
67 * debugfs_file_get - mark the beginning of file data access
68 * @dentry: the dentry object whose data is being accessed.
69 *
70 * Up to a matching call to debugfs_file_put(), any successive call
71 * into the file removing functions debugfs_remove() and
72 * debugfs_remove_recursive() will block. Since associated private
73 * file data may only get freed after a successful return of any of
74 * the removal functions, you may safely access it after a successful
75 * call to debugfs_file_get() without worrying about lifetime issues.
76 *
77 * If -%EIO is returned, the file has already been removed and thus,
78 * it is not safe to access any of its data. If, on the other hand,
79 * it is allowed to access the file data, zero is returned.
80 */
81int debugfs_file_get(struct dentry *dentry)
82{
83 struct debugfs_fsdata *fsd;
84 void *d_fsd;
85
86 d_fsd = READ_ONCE(dentry->d_fsdata);
87 if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
88 fsd = d_fsd;
89 } else {
90 fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
91 if (!fsd)
92 return -ENOMEM;
93
94 fsd->real_fops = (void *)((unsigned long)d_fsd &
95 ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
96 refcount_set(&fsd->active_users, 1);
97 init_completion(&fsd->active_users_drained);
98 if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
99 kfree(fsd);
100 fsd = READ_ONCE(dentry->d_fsdata);
101 }
102 }
103
104 /*
105 * In case of a successful cmpxchg() above, this check is
106 * strictly necessary and must follow it, see the comment in
107 * __debugfs_remove_file().
108 * OTOH, if the cmpxchg() hasn't been executed or wasn't
109 * successful, this serves the purpose of not starving
110 * removers.
111 */
112 if (d_unlinked(dentry))
113 return -EIO;
114
115 if (!refcount_inc_not_zero(&fsd->active_users))
116 return -EIO;
117
118 return 0;
119}
120EXPORT_SYMBOL_GPL(debugfs_file_get);
121
122/**
123 * debugfs_file_put - mark the end of file data access
124 * @dentry: the dentry object formerly passed to
125 * debugfs_file_get().
126 *
127 * Allow any ongoing concurrent call into debugfs_remove() or
128 * debugfs_remove_recursive() blocked by a former call to
129 * debugfs_file_get() to proceed and return to its caller.
130 */
131void debugfs_file_put(struct dentry *dentry)
132{
133 struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
134
135 if (refcount_dec_and_test(&fsd->active_users))
136 complete(&fsd->active_users_drained);
137}
138EXPORT_SYMBOL_GPL(debugfs_file_put);
139
140/*
141 * Only permit access to world-readable files when the kernel is locked down.
142 * We also need to exclude any file that has ways to write or alter it as root
143 * can bypass the permissions check.
144 */
145static bool debugfs_is_locked_down(struct inode *inode,
146 struct file *filp,
147 const struct file_operations *real_fops)
148{
149 if ((inode->i_mode & 07777) == 0444 &&
150 !(filp->f_mode & FMODE_WRITE) &&
151 !real_fops->unlocked_ioctl &&
152 !real_fops->compat_ioctl &&
153 !real_fops->mmap)
154 return false;
155
156 return security_locked_down(LOCKDOWN_DEBUGFS);
157}
158
159static int open_proxy_open(struct inode *inode, struct file *filp)
160{
161 struct dentry *dentry = F_DENTRY(filp);
162 const struct file_operations *real_fops = NULL;
163 int r;
164
165 r = debugfs_file_get(dentry);
166 if (r)
167 return r == -EIO ? -ENOENT : r;
168
169 real_fops = debugfs_real_fops(filp);
170
171 r = debugfs_is_locked_down(inode, filp, real_fops);
172 if (r)
173 goto out;
174
175 real_fops = fops_get(real_fops);
176 if (!real_fops) {
177 /* Huh? Module did not clean up after itself at exit? */
178 WARN(1, "debugfs file owner did not clean up at exit: %pd",
179 dentry);
180 r = -ENXIO;
181 goto out;
182 }
183 replace_fops(filp, real_fops);
184
185 if (real_fops->open)
186 r = real_fops->open(inode, filp);
187
188out:
189 debugfs_file_put(dentry);
190 return r;
191}
192
193const struct file_operations debugfs_open_proxy_file_operations = {
194 .open = open_proxy_open,
195};
196
197#define PROTO(args...) args
198#define ARGS(args...) args
199
200#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
201static ret_type full_proxy_ ## name(proto) \
202{ \
203 struct dentry *dentry = F_DENTRY(filp); \
204 const struct file_operations *real_fops; \
205 ret_type r; \
206 \
207 r = debugfs_file_get(dentry); \
208 if (unlikely(r)) \
209 return r; \
210 real_fops = debugfs_real_fops(filp); \
211 r = real_fops->name(args); \
212 debugfs_file_put(dentry); \
213 return r; \
214}
215
216FULL_PROXY_FUNC(llseek, loff_t, filp,
217 PROTO(struct file *filp, loff_t offset, int whence),
218 ARGS(filp, offset, whence));
219
220FULL_PROXY_FUNC(read, ssize_t, filp,
221 PROTO(struct file *filp, char __user *buf, size_t size,
222 loff_t *ppos),
223 ARGS(filp, buf, size, ppos));
224
225FULL_PROXY_FUNC(write, ssize_t, filp,
226 PROTO(struct file *filp, const char __user *buf, size_t size,
227 loff_t *ppos),
228 ARGS(filp, buf, size, ppos));
229
230FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
231 PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
232 ARGS(filp, cmd, arg));
233
234static __poll_t full_proxy_poll(struct file *filp,
235 struct poll_table_struct *wait)
236{
237 struct dentry *dentry = F_DENTRY(filp);
238 __poll_t r = 0;
239 const struct file_operations *real_fops;
240
241 if (debugfs_file_get(dentry))
242 return EPOLLHUP;
243
244 real_fops = debugfs_real_fops(filp);
245 r = real_fops->poll(filp, wait);
246 debugfs_file_put(dentry);
247 return r;
248}
249
250static int full_proxy_release(struct inode *inode, struct file *filp)
251{
252 const struct dentry *dentry = F_DENTRY(filp);
253 const struct file_operations *real_fops = debugfs_real_fops(filp);
254 const struct file_operations *proxy_fops = filp->f_op;
255 int r = 0;
256
257 /*
258 * We must not protect this against removal races here: the
259 * original releaser should be called unconditionally in order
260 * not to leak any resources. Releasers must not assume that
261 * ->i_private is still being meaningful here.
262 */
263 if (real_fops->release)
264 r = real_fops->release(inode, filp);
265
266 replace_fops(filp, d_inode(dentry)->i_fop);
267 kfree((void *)proxy_fops);
268 fops_put(real_fops);
269 return r;
270}
271
272static void __full_proxy_fops_init(struct file_operations *proxy_fops,
273 const struct file_operations *real_fops)
274{
275 proxy_fops->release = full_proxy_release;
276 if (real_fops->llseek)
277 proxy_fops->llseek = full_proxy_llseek;
278 if (real_fops->read)
279 proxy_fops->read = full_proxy_read;
280 if (real_fops->write)
281 proxy_fops->write = full_proxy_write;
282 if (real_fops->poll)
283 proxy_fops->poll = full_proxy_poll;
284 if (real_fops->unlocked_ioctl)
285 proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
286}
287
288static int full_proxy_open(struct inode *inode, struct file *filp)
289{
290 struct dentry *dentry = F_DENTRY(filp);
291 const struct file_operations *real_fops = NULL;
292 struct file_operations *proxy_fops = NULL;
293 int r;
294
295 r = debugfs_file_get(dentry);
296 if (r)
297 return r == -EIO ? -ENOENT : r;
298
299 real_fops = debugfs_real_fops(filp);
300
301 r = debugfs_is_locked_down(inode, filp, real_fops);
302 if (r)
303 goto out;
304
305 real_fops = fops_get(real_fops);
306 if (!real_fops) {
307 /* Huh? Module did not cleanup after itself at exit? */
308 WARN(1, "debugfs file owner did not clean up at exit: %pd",
309 dentry);
310 r = -ENXIO;
311 goto out;
312 }
313
314 proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
315 if (!proxy_fops) {
316 r = -ENOMEM;
317 goto free_proxy;
318 }
319 __full_proxy_fops_init(proxy_fops, real_fops);
320 replace_fops(filp, proxy_fops);
321
322 if (real_fops->open) {
323 r = real_fops->open(inode, filp);
324 if (r) {
325 replace_fops(filp, d_inode(dentry)->i_fop);
326 goto free_proxy;
327 } else if (filp->f_op != proxy_fops) {
328 /* No protection against file removal anymore. */
329 WARN(1, "debugfs file owner replaced proxy fops: %pd",
330 dentry);
331 goto free_proxy;
332 }
333 }
334
335 goto out;
336free_proxy:
337 kfree(proxy_fops);
338 fops_put(real_fops);
339out:
340 debugfs_file_put(dentry);
341 return r;
342}
343
344const struct file_operations debugfs_full_proxy_file_operations = {
345 .open = full_proxy_open,
346};
347
348ssize_t debugfs_attr_read(struct file *file, char __user *buf,
349 size_t len, loff_t *ppos)
350{
351 struct dentry *dentry = F_DENTRY(file);
352 ssize_t ret;
353
354 ret = debugfs_file_get(dentry);
355 if (unlikely(ret))
356 return ret;
357 ret = simple_attr_read(file, buf, len, ppos);
358 debugfs_file_put(dentry);
359 return ret;
360}
361EXPORT_SYMBOL_GPL(debugfs_attr_read);
362
363ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
364 size_t len, loff_t *ppos)
365{
366 struct dentry *dentry = F_DENTRY(file);
367 ssize_t ret;
368
369 ret = debugfs_file_get(dentry);
370 if (unlikely(ret))
371 return ret;
372 ret = simple_attr_write(file, buf, len, ppos);
373 debugfs_file_put(dentry);
374 return ret;
375}
376EXPORT_SYMBOL_GPL(debugfs_attr_write);
377
378static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
379 struct dentry *parent, void *value,
380 const struct file_operations *fops,
381 const struct file_operations *fops_ro,
382 const struct file_operations *fops_wo)
383{
384 /* if there are no write bits set, make read only */
385 if (!(mode & S_IWUGO))
386 return debugfs_create_file_unsafe(name, mode, parent, value,
387 fops_ro);
388 /* if there are no read bits set, make write only */
389 if (!(mode & S_IRUGO))
390 return debugfs_create_file_unsafe(name, mode, parent, value,
391 fops_wo);
392
393 return debugfs_create_file_unsafe(name, mode, parent, value, fops);
394}
395
396static int debugfs_u8_set(void *data, u64 val)
397{
398 *(u8 *)data = val;
399 return 0;
400}
401static int debugfs_u8_get(void *data, u64 *val)
402{
403 *val = *(u8 *)data;
404 return 0;
405}
406DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
407DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
408DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
409
410/**
411 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
412 * @name: a pointer to a string containing the name of the file to create.
413 * @mode: the permission that the file should have
414 * @parent: a pointer to the parent dentry for this file. This should be a
415 * directory dentry if set. If this parameter is %NULL, then the
416 * file will be created in the root of the debugfs filesystem.
417 * @value: a pointer to the variable that the file should read to and write
418 * from.
419 *
420 * This function creates a file in debugfs with the given name that
421 * contains the value of the variable @value. If the @mode variable is so
422 * set, it can be read from, and written to.
423 *
424 * This function will return a pointer to a dentry if it succeeds. This
425 * pointer must be passed to the debugfs_remove() function when the file is
426 * to be removed (no automatic cleanup happens if your module is unloaded,
427 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
428 * returned.
429 *
430 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
431 * be returned.
432 */
433struct dentry *debugfs_create_u8(const char *name, umode_t mode,
434 struct dentry *parent, u8 *value)
435{
436 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
437 &fops_u8_ro, &fops_u8_wo);
438}
439EXPORT_SYMBOL_GPL(debugfs_create_u8);
440
441static int debugfs_u16_set(void *data, u64 val)
442{
443 *(u16 *)data = val;
444 return 0;
445}
446static int debugfs_u16_get(void *data, u64 *val)
447{
448 *val = *(u16 *)data;
449 return 0;
450}
451DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
452DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
453DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
454
455/**
456 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
457 * @name: a pointer to a string containing the name of the file to create.
458 * @mode: the permission that the file should have
459 * @parent: a pointer to the parent dentry for this file. This should be a
460 * directory dentry if set. If this parameter is %NULL, then the
461 * file will be created in the root of the debugfs filesystem.
462 * @value: a pointer to the variable that the file should read to and write
463 * from.
464 *
465 * This function creates a file in debugfs with the given name that
466 * contains the value of the variable @value. If the @mode variable is so
467 * set, it can be read from, and written to.
468 *
469 * This function will return a pointer to a dentry if it succeeds. This
470 * pointer must be passed to the debugfs_remove() function when the file is
471 * to be removed (no automatic cleanup happens if your module is unloaded,
472 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
473 * returned.
474 *
475 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
476 * be returned.
477 */
478struct dentry *debugfs_create_u16(const char *name, umode_t mode,
479 struct dentry *parent, u16 *value)
480{
481 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
482 &fops_u16_ro, &fops_u16_wo);
483}
484EXPORT_SYMBOL_GPL(debugfs_create_u16);
485
486static int debugfs_u32_set(void *data, u64 val)
487{
488 *(u32 *)data = val;
489 return 0;
490}
491static int debugfs_u32_get(void *data, u64 *val)
492{
493 *val = *(u32 *)data;
494 return 0;
495}
496DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
497DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
498DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
499
500/**
501 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
502 * @name: a pointer to a string containing the name of the file to create.
503 * @mode: the permission that the file should have
504 * @parent: a pointer to the parent dentry for this file. This should be a
505 * directory dentry if set. If this parameter is %NULL, then the
506 * file will be created in the root of the debugfs filesystem.
507 * @value: a pointer to the variable that the file should read to and write
508 * from.
509 *
510 * This function creates a file in debugfs with the given name that
511 * contains the value of the variable @value. If the @mode variable is so
512 * set, it can be read from, and written to.
513 *
514 * This function will return a pointer to a dentry if it succeeds. This
515 * pointer must be passed to the debugfs_remove() function when the file is
516 * to be removed (no automatic cleanup happens if your module is unloaded,
517 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
518 * returned.
519 *
520 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
521 * be returned.
522 */
523struct dentry *debugfs_create_u32(const char *name, umode_t mode,
524 struct dentry *parent, u32 *value)
525{
526 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
527 &fops_u32_ro, &fops_u32_wo);
528}
529EXPORT_SYMBOL_GPL(debugfs_create_u32);
530
531static int debugfs_u64_set(void *data, u64 val)
532{
533 *(u64 *)data = val;
534 return 0;
535}
536
537static int debugfs_u64_get(void *data, u64 *val)
538{
539 *val = *(u64 *)data;
540 return 0;
541}
542DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
543DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
544DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
545
546/**
547 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
548 * @name: a pointer to a string containing the name of the file to create.
549 * @mode: the permission that the file should have
550 * @parent: a pointer to the parent dentry for this file. This should be a
551 * directory dentry if set. If this parameter is %NULL, then the
552 * file will be created in the root of the debugfs filesystem.
553 * @value: a pointer to the variable that the file should read to and write
554 * from.
555 *
556 * This function creates a file in debugfs with the given name that
557 * contains the value of the variable @value. If the @mode variable is so
558 * set, it can be read from, and written to.
559 *
560 * This function will return a pointer to a dentry if it succeeds. This
561 * pointer must be passed to the debugfs_remove() function when the file is
562 * to be removed (no automatic cleanup happens if your module is unloaded,
563 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
564 * returned.
565 *
566 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
567 * be returned.
568 */
569struct dentry *debugfs_create_u64(const char *name, umode_t mode,
570 struct dentry *parent, u64 *value)
571{
572 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
573 &fops_u64_ro, &fops_u64_wo);
574}
575EXPORT_SYMBOL_GPL(debugfs_create_u64);
576
577static int debugfs_ulong_set(void *data, u64 val)
578{
579 *(unsigned long *)data = val;
580 return 0;
581}
582
583static int debugfs_ulong_get(void *data, u64 *val)
584{
585 *val = *(unsigned long *)data;
586 return 0;
587}
588DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
589 "%llu\n");
590DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
591DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
592
593/**
594 * debugfs_create_ulong - create a debugfs file that is used to read and write
595 * an unsigned long value.
596 * @name: a pointer to a string containing the name of the file to create.
597 * @mode: the permission that the file should have
598 * @parent: a pointer to the parent dentry for this file. This should be a
599 * directory dentry if set. If this parameter is %NULL, then the
600 * file will be created in the root of the debugfs filesystem.
601 * @value: a pointer to the variable that the file should read to and write
602 * from.
603 *
604 * This function creates a file in debugfs with the given name that
605 * contains the value of the variable @value. If the @mode variable is so
606 * set, it can be read from, and written to.
607 *
608 * This function will return a pointer to a dentry if it succeeds. This
609 * pointer must be passed to the debugfs_remove() function when the file is
610 * to be removed (no automatic cleanup happens if your module is unloaded,
611 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
612 * returned.
613 *
614 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
615 * be returned.
616 */
617struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
618 struct dentry *parent, unsigned long *value)
619{
620 return debugfs_create_mode_unsafe(name, mode, parent, value,
621 &fops_ulong, &fops_ulong_ro,
622 &fops_ulong_wo);
623}
624EXPORT_SYMBOL_GPL(debugfs_create_ulong);
625
626DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
627DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
628DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
629
630DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
631 "0x%04llx\n");
632DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
633DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
634
635DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
636 "0x%08llx\n");
637DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
638DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
639
640DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
641 "0x%016llx\n");
642DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
643DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
644
645/*
646 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
647 *
648 * These functions are exactly the same as the above functions (but use a hex
649 * output for the decimal challenged). For details look at the above unsigned
650 * decimal functions.
651 */
652
653/**
654 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
655 * @name: a pointer to a string containing the name of the file to create.
656 * @mode: the permission that the file should have
657 * @parent: a pointer to the parent dentry for this file. This should be a
658 * directory dentry if set. If this parameter is %NULL, then the
659 * file will be created in the root of the debugfs filesystem.
660 * @value: a pointer to the variable that the file should read to and write
661 * from.
662 */
663struct dentry *debugfs_create_x8(const char *name, umode_t mode,
664 struct dentry *parent, u8 *value)
665{
666 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
667 &fops_x8_ro, &fops_x8_wo);
668}
669EXPORT_SYMBOL_GPL(debugfs_create_x8);
670
671/**
672 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
673 * @name: a pointer to a string containing the name of the file to create.
674 * @mode: the permission that the file should have
675 * @parent: a pointer to the parent dentry for this file. This should be a
676 * directory dentry if set. If this parameter is %NULL, then the
677 * file will be created in the root of the debugfs filesystem.
678 * @value: a pointer to the variable that the file should read to and write
679 * from.
680 */
681struct dentry *debugfs_create_x16(const char *name, umode_t mode,
682 struct dentry *parent, u16 *value)
683{
684 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
685 &fops_x16_ro, &fops_x16_wo);
686}
687EXPORT_SYMBOL_GPL(debugfs_create_x16);
688
689/**
690 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
691 * @name: a pointer to a string containing the name of the file to create.
692 * @mode: the permission that the file should have
693 * @parent: a pointer to the parent dentry for this file. This should be a
694 * directory dentry if set. If this parameter is %NULL, then the
695 * file will be created in the root of the debugfs filesystem.
696 * @value: a pointer to the variable that the file should read to and write
697 * from.
698 */
699struct dentry *debugfs_create_x32(const char *name, umode_t mode,
700 struct dentry *parent, u32 *value)
701{
702 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
703 &fops_x32_ro, &fops_x32_wo);
704}
705EXPORT_SYMBOL_GPL(debugfs_create_x32);
706
707/**
708 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
709 * @name: a pointer to a string containing the name of the file to create.
710 * @mode: the permission that the file should have
711 * @parent: a pointer to the parent dentry for this file. This should be a
712 * directory dentry if set. If this parameter is %NULL, then the
713 * file will be created in the root of the debugfs filesystem.
714 * @value: a pointer to the variable that the file should read to and write
715 * from.
716 */
717struct dentry *debugfs_create_x64(const char *name, umode_t mode,
718 struct dentry *parent, u64 *value)
719{
720 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64,
721 &fops_x64_ro, &fops_x64_wo);
722}
723EXPORT_SYMBOL_GPL(debugfs_create_x64);
724
725
726static int debugfs_size_t_set(void *data, u64 val)
727{
728 *(size_t *)data = val;
729 return 0;
730}
731static int debugfs_size_t_get(void *data, u64 *val)
732{
733 *val = *(size_t *)data;
734 return 0;
735}
736DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
737 "%llu\n"); /* %llu and %zu are more or less the same */
738DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
739DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
740
741/**
742 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
743 * @name: a pointer to a string containing the name of the file to create.
744 * @mode: the permission that the file should have
745 * @parent: a pointer to the parent dentry for this file. This should be a
746 * directory dentry if set. If this parameter is %NULL, then the
747 * file will be created in the root of the debugfs filesystem.
748 * @value: a pointer to the variable that the file should read to and write
749 * from.
750 */
751struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
752 struct dentry *parent, size_t *value)
753{
754 return debugfs_create_mode_unsafe(name, mode, parent, value,
755 &fops_size_t, &fops_size_t_ro,
756 &fops_size_t_wo);
757}
758EXPORT_SYMBOL_GPL(debugfs_create_size_t);
759
760static int debugfs_atomic_t_set(void *data, u64 val)
761{
762 atomic_set((atomic_t *)data, val);
763 return 0;
764}
765static int debugfs_atomic_t_get(void *data, u64 *val)
766{
767 *val = atomic_read((atomic_t *)data);
768 return 0;
769}
770DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
771 debugfs_atomic_t_set, "%lld\n");
772DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
773 "%lld\n");
774DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
775 "%lld\n");
776
777/**
778 * debugfs_create_atomic_t - create a debugfs file that is used to read and
779 * write an atomic_t value
780 * @name: a pointer to a string containing the name of the file to create.
781 * @mode: the permission that the file should have
782 * @parent: a pointer to the parent dentry for this file. This should be a
783 * directory dentry if set. If this parameter is %NULL, then the
784 * file will be created in the root of the debugfs filesystem.
785 * @value: a pointer to the variable that the file should read to and write
786 * from.
787 */
788struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
789 struct dentry *parent, atomic_t *value)
790{
791 return debugfs_create_mode_unsafe(name, mode, parent, value,
792 &fops_atomic_t, &fops_atomic_t_ro,
793 &fops_atomic_t_wo);
794}
795EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
796
797ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
798 size_t count, loff_t *ppos)
799{
800 char buf[3];
801 bool val;
802 int r;
803 struct dentry *dentry = F_DENTRY(file);
804
805 r = debugfs_file_get(dentry);
806 if (unlikely(r))
807 return r;
808 val = *(bool *)file->private_data;
809 debugfs_file_put(dentry);
810
811 if (val)
812 buf[0] = 'Y';
813 else
814 buf[0] = 'N';
815 buf[1] = '\n';
816 buf[2] = 0x00;
817 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
818}
819EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
820
821ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
822 size_t count, loff_t *ppos)
823{
824 bool bv;
825 int r;
826 bool *val = file->private_data;
827 struct dentry *dentry = F_DENTRY(file);
828
829 r = kstrtobool_from_user(user_buf, count, &bv);
830 if (!r) {
831 r = debugfs_file_get(dentry);
832 if (unlikely(r))
833 return r;
834 *val = bv;
835 debugfs_file_put(dentry);
836 }
837
838 return count;
839}
840EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
841
842static const struct file_operations fops_bool = {
843 .read = debugfs_read_file_bool,
844 .write = debugfs_write_file_bool,
845 .open = simple_open,
846 .llseek = default_llseek,
847};
848
849static const struct file_operations fops_bool_ro = {
850 .read = debugfs_read_file_bool,
851 .open = simple_open,
852 .llseek = default_llseek,
853};
854
855static const struct file_operations fops_bool_wo = {
856 .write = debugfs_write_file_bool,
857 .open = simple_open,
858 .llseek = default_llseek,
859};
860
861/**
862 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
863 * @name: a pointer to a string containing the name of the file to create.
864 * @mode: the permission that the file should have
865 * @parent: a pointer to the parent dentry for this file. This should be a
866 * directory dentry if set. If this parameter is %NULL, then the
867 * file will be created in the root of the debugfs filesystem.
868 * @value: a pointer to the variable that the file should read to and write
869 * from.
870 *
871 * This function creates a file in debugfs with the given name that
872 * contains the value of the variable @value. If the @mode variable is so
873 * set, it can be read from, and written to.
874 *
875 * This function will return a pointer to a dentry if it succeeds. This
876 * pointer must be passed to the debugfs_remove() function when the file is
877 * to be removed (no automatic cleanup happens if your module is unloaded,
878 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
879 * returned.
880 *
881 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
882 * be returned.
883 */
884struct dentry *debugfs_create_bool(const char *name, umode_t mode,
885 struct dentry *parent, bool *value)
886{
887 return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
888 &fops_bool_ro, &fops_bool_wo);
889}
890EXPORT_SYMBOL_GPL(debugfs_create_bool);
891
892static ssize_t read_file_blob(struct file *file, char __user *user_buf,
893 size_t count, loff_t *ppos)
894{
895 struct debugfs_blob_wrapper *blob = file->private_data;
896 struct dentry *dentry = F_DENTRY(file);
897 ssize_t r;
898
899 r = debugfs_file_get(dentry);
900 if (unlikely(r))
901 return r;
902 r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
903 blob->size);
904 debugfs_file_put(dentry);
905 return r;
906}
907
908static const struct file_operations fops_blob = {
909 .read = read_file_blob,
910 .open = simple_open,
911 .llseek = default_llseek,
912};
913
914/**
915 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
916 * @name: a pointer to a string containing the name of the file to create.
917 * @mode: the permission that the file should have
918 * @parent: a pointer to the parent dentry for this file. This should be a
919 * directory dentry if set. If this parameter is %NULL, then the
920 * file will be created in the root of the debugfs filesystem.
921 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
922 * to the blob data and the size of the data.
923 *
924 * This function creates a file in debugfs with the given name that exports
925 * @blob->data as a binary blob. If the @mode variable is so set it can be
926 * read from. Writing is not supported.
927 *
928 * This function will return a pointer to a dentry if it succeeds. This
929 * pointer must be passed to the debugfs_remove() function when the file is
930 * to be removed (no automatic cleanup happens if your module is unloaded,
931 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
932 * returned.
933 *
934 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
935 * be returned.
936 */
937struct dentry *debugfs_create_blob(const char *name, umode_t mode,
938 struct dentry *parent,
939 struct debugfs_blob_wrapper *blob)
940{
941 return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob);
942}
943EXPORT_SYMBOL_GPL(debugfs_create_blob);
944
945struct array_data {
946 void *array;
947 u32 elements;
948};
949
950static size_t u32_format_array(char *buf, size_t bufsize,
951 u32 *array, int array_size)
952{
953 size_t ret = 0;
954
955 while (--array_size >= 0) {
956 size_t len;
957 char term = array_size ? ' ' : '\n';
958
959 len = snprintf(buf, bufsize, "%u%c", *array++, term);
960 ret += len;
961
962 buf += len;
963 bufsize -= len;
964 }
965 return ret;
966}
967
968static int u32_array_open(struct inode *inode, struct file *file)
969{
970 struct array_data *data = inode->i_private;
971 int size, elements = data->elements;
972 char *buf;
973
974 /*
975 * Max size:
976 * - 10 digits + ' '/'\n' = 11 bytes per number
977 * - terminating NUL character
978 */
979 size = elements*11;
980 buf = kmalloc(size+1, GFP_KERNEL);
981 if (!buf)
982 return -ENOMEM;
983 buf[size] = 0;
984
985 file->private_data = buf;
986 u32_format_array(buf, size, data->array, data->elements);
987
988 return nonseekable_open(inode, file);
989}
990
991static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
992 loff_t *ppos)
993{
994 size_t size = strlen(file->private_data);
995
996 return simple_read_from_buffer(buf, len, ppos,
997 file->private_data, size);
998}
999
1000static int u32_array_release(struct inode *inode, struct file *file)
1001{
1002 kfree(file->private_data);
1003
1004 return 0;
1005}
1006
1007static const struct file_operations u32_array_fops = {
1008 .owner = THIS_MODULE,
1009 .open = u32_array_open,
1010 .release = u32_array_release,
1011 .read = u32_array_read,
1012 .llseek = no_llseek,
1013};
1014
1015/**
1016 * debugfs_create_u32_array - create a debugfs file that is used to read u32
1017 * array.
1018 * @name: a pointer to a string containing the name of the file to create.
1019 * @mode: the permission that the file should have.
1020 * @parent: a pointer to the parent dentry for this file. This should be a
1021 * directory dentry if set. If this parameter is %NULL, then the
1022 * file will be created in the root of the debugfs filesystem.
1023 * @array: u32 array that provides data.
1024 * @elements: total number of elements in the array.
1025 *
1026 * This function creates a file in debugfs with the given name that exports
1027 * @array as data. If the @mode variable is so set it can be read from.
1028 * Writing is not supported. Seek within the file is also not supported.
1029 * Once array is created its size can not be changed.
1030 */
1031void debugfs_create_u32_array(const char *name, umode_t mode,
1032 struct dentry *parent, u32 *array, u32 elements)
1033{
1034 struct array_data *data = kmalloc(sizeof(*data), GFP_KERNEL);
1035
1036 if (data == NULL)
1037 return;
1038
1039 data->array = array;
1040 data->elements = elements;
1041
1042 debugfs_create_file_unsafe(name, mode, parent, data, &u32_array_fops);
1043}
1044EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
1045
1046#ifdef CONFIG_HAS_IOMEM
1047
1048/*
1049 * The regset32 stuff is used to print 32-bit registers using the
1050 * seq_file utilities. We offer printing a register set in an already-opened
1051 * sequential file or create a debugfs file that only prints a regset32.
1052 */
1053
1054/**
1055 * debugfs_print_regs32 - use seq_print to describe a set of registers
1056 * @s: the seq_file structure being used to generate output
1057 * @regs: an array if struct debugfs_reg32 structures
1058 * @nregs: the length of the above array
1059 * @base: the base address to be used in reading the registers
1060 * @prefix: a string to be prefixed to every output line
1061 *
1062 * This function outputs a text block describing the current values of
1063 * some 32-bit hardware registers. It is meant to be used within debugfs
1064 * files based on seq_file that need to show registers, intermixed with other
1065 * information. The prefix argument may be used to specify a leading string,
1066 * because some peripherals have several blocks of identical registers,
1067 * for example configuration of dma channels
1068 */
1069void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
1070 int nregs, void __iomem *base, char *prefix)
1071{
1072 int i;
1073
1074 for (i = 0; i < nregs; i++, regs++) {
1075 if (prefix)
1076 seq_printf(s, "%s", prefix);
1077 seq_printf(s, "%s = 0x%08x\n", regs->name,
1078 readl(base + regs->offset));
1079 if (seq_has_overflowed(s))
1080 break;
1081 }
1082}
1083EXPORT_SYMBOL_GPL(debugfs_print_regs32);
1084
1085static int debugfs_show_regset32(struct seq_file *s, void *data)
1086{
1087 struct debugfs_regset32 *regset = s->private;
1088
1089 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
1090 return 0;
1091}
1092
1093static int debugfs_open_regset32(struct inode *inode, struct file *file)
1094{
1095 return single_open(file, debugfs_show_regset32, inode->i_private);
1096}
1097
1098static const struct file_operations fops_regset32 = {
1099 .open = debugfs_open_regset32,
1100 .read = seq_read,
1101 .llseek = seq_lseek,
1102 .release = single_release,
1103};
1104
1105/**
1106 * debugfs_create_regset32 - create a debugfs file that returns register values
1107 * @name: a pointer to a string containing the name of the file to create.
1108 * @mode: the permission that the file should have
1109 * @parent: a pointer to the parent dentry for this file. This should be a
1110 * directory dentry if set. If this parameter is %NULL, then the
1111 * file will be created in the root of the debugfs filesystem.
1112 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
1113 * to an array of register definitions, the array size and the base
1114 * address where the register bank is to be found.
1115 *
1116 * This function creates a file in debugfs with the given name that reports
1117 * the names and values of a set of 32-bit registers. If the @mode variable
1118 * is so set it can be read from. Writing is not supported.
1119 *
1120 * This function will return a pointer to a dentry if it succeeds. This
1121 * pointer must be passed to the debugfs_remove() function when the file is
1122 * to be removed (no automatic cleanup happens if your module is unloaded,
1123 * you are responsible here.) If an error occurs, %ERR_PTR(-ERROR) will be
1124 * returned.
1125 *
1126 * If debugfs is not enabled in the kernel, the value %ERR_PTR(-ENODEV) will
1127 * be returned.
1128 */
1129struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
1130 struct dentry *parent,
1131 struct debugfs_regset32 *regset)
1132{
1133 return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
1134}
1135EXPORT_SYMBOL_GPL(debugfs_create_regset32);
1136
1137#endif /* CONFIG_HAS_IOMEM */
1138
1139struct debugfs_devm_entry {
1140 int (*read)(struct seq_file *seq, void *data);
1141 struct device *dev;
1142};
1143
1144static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
1145{
1146 struct debugfs_devm_entry *entry = inode->i_private;
1147
1148 return single_open(f, entry->read, entry->dev);
1149}
1150
1151static const struct file_operations debugfs_devm_entry_ops = {
1152 .owner = THIS_MODULE,
1153 .open = debugfs_devm_entry_open,
1154 .release = single_release,
1155 .read = seq_read,
1156 .llseek = seq_lseek
1157};
1158
1159/**
1160 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
1161 *
1162 * @dev: device related to this debugfs file.
1163 * @name: name of the debugfs file.
1164 * @parent: a pointer to the parent dentry for this file. This should be a
1165 * directory dentry if set. If this parameter is %NULL, then the
1166 * file will be created in the root of the debugfs filesystem.
1167 * @read_fn: function pointer called to print the seq_file content.
1168 */
1169struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
1170 struct dentry *parent,
1171 int (*read_fn)(struct seq_file *s,
1172 void *data))
1173{
1174 struct debugfs_devm_entry *entry;
1175
1176 if (IS_ERR(parent))
1177 return ERR_PTR(-ENOENT);
1178
1179 entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
1180 if (!entry)
1181 return ERR_PTR(-ENOMEM);
1182
1183 entry->read = read_fn;
1184 entry->dev = dev;
1185
1186 return debugfs_create_file(name, S_IRUGO, parent, entry,
1187 &debugfs_devm_entry_ops);
1188}
1189EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
1190
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * file.c - part of debugfs, a tiny little debug file system
4 *
5 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (C) 2004 IBM Inc.
7 *
8 * debugfs is for people to use instead of /proc or /sys.
9 * See Documentation/filesystems/ for more details.
10 */
11
12#include <linux/module.h>
13#include <linux/fs.h>
14#include <linux/seq_file.h>
15#include <linux/pagemap.h>
16#include <linux/debugfs.h>
17#include <linux/io.h>
18#include <linux/slab.h>
19#include <linux/atomic.h>
20#include <linux/device.h>
21#include <linux/pm_runtime.h>
22#include <linux/poll.h>
23#include <linux/security.h>
24
25#include "internal.h"
26
27struct poll_table_struct;
28
29static ssize_t default_read_file(struct file *file, char __user *buf,
30 size_t count, loff_t *ppos)
31{
32 return 0;
33}
34
35static ssize_t default_write_file(struct file *file, const char __user *buf,
36 size_t count, loff_t *ppos)
37{
38 return count;
39}
40
41const struct file_operations debugfs_noop_file_operations = {
42 .read = default_read_file,
43 .write = default_write_file,
44 .open = simple_open,
45 .llseek = noop_llseek,
46};
47
48#define F_DENTRY(filp) ((filp)->f_path.dentry)
49
50const struct file_operations *debugfs_real_fops(const struct file *filp)
51{
52 struct debugfs_fsdata *fsd = F_DENTRY(filp)->d_fsdata;
53
54 if ((unsigned long)fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT) {
55 /*
56 * Urgh, we've been called w/o a protecting
57 * debugfs_file_get().
58 */
59 WARN_ON(1);
60 return NULL;
61 }
62
63 return fsd->real_fops;
64}
65EXPORT_SYMBOL_GPL(debugfs_real_fops);
66
67/**
68 * debugfs_file_get - mark the beginning of file data access
69 * @dentry: the dentry object whose data is being accessed.
70 *
71 * Up to a matching call to debugfs_file_put(), any successive call
72 * into the file removing functions debugfs_remove() and
73 * debugfs_remove_recursive() will block. Since associated private
74 * file data may only get freed after a successful return of any of
75 * the removal functions, you may safely access it after a successful
76 * call to debugfs_file_get() without worrying about lifetime issues.
77 *
78 * If -%EIO is returned, the file has already been removed and thus,
79 * it is not safe to access any of its data. If, on the other hand,
80 * it is allowed to access the file data, zero is returned.
81 */
82int debugfs_file_get(struct dentry *dentry)
83{
84 struct debugfs_fsdata *fsd;
85 void *d_fsd;
86
87 d_fsd = READ_ONCE(dentry->d_fsdata);
88 if (!((unsigned long)d_fsd & DEBUGFS_FSDATA_IS_REAL_FOPS_BIT)) {
89 fsd = d_fsd;
90 } else {
91 fsd = kmalloc(sizeof(*fsd), GFP_KERNEL);
92 if (!fsd)
93 return -ENOMEM;
94
95 fsd->real_fops = (void *)((unsigned long)d_fsd &
96 ~DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
97 refcount_set(&fsd->active_users, 1);
98 init_completion(&fsd->active_users_drained);
99 if (cmpxchg(&dentry->d_fsdata, d_fsd, fsd) != d_fsd) {
100 kfree(fsd);
101 fsd = READ_ONCE(dentry->d_fsdata);
102 }
103 }
104
105 /*
106 * In case of a successful cmpxchg() above, this check is
107 * strictly necessary and must follow it, see the comment in
108 * __debugfs_remove_file().
109 * OTOH, if the cmpxchg() hasn't been executed or wasn't
110 * successful, this serves the purpose of not starving
111 * removers.
112 */
113 if (d_unlinked(dentry))
114 return -EIO;
115
116 if (!refcount_inc_not_zero(&fsd->active_users))
117 return -EIO;
118
119 return 0;
120}
121EXPORT_SYMBOL_GPL(debugfs_file_get);
122
123/**
124 * debugfs_file_put - mark the end of file data access
125 * @dentry: the dentry object formerly passed to
126 * debugfs_file_get().
127 *
128 * Allow any ongoing concurrent call into debugfs_remove() or
129 * debugfs_remove_recursive() blocked by a former call to
130 * debugfs_file_get() to proceed and return to its caller.
131 */
132void debugfs_file_put(struct dentry *dentry)
133{
134 struct debugfs_fsdata *fsd = READ_ONCE(dentry->d_fsdata);
135
136 if (refcount_dec_and_test(&fsd->active_users))
137 complete(&fsd->active_users_drained);
138}
139EXPORT_SYMBOL_GPL(debugfs_file_put);
140
141/*
142 * Only permit access to world-readable files when the kernel is locked down.
143 * We also need to exclude any file that has ways to write or alter it as root
144 * can bypass the permissions check.
145 */
146static int debugfs_locked_down(struct inode *inode,
147 struct file *filp,
148 const struct file_operations *real_fops)
149{
150 if ((inode->i_mode & 07777 & ~0444) == 0 &&
151 !(filp->f_mode & FMODE_WRITE) &&
152 !real_fops->unlocked_ioctl &&
153 !real_fops->compat_ioctl &&
154 !real_fops->mmap)
155 return 0;
156
157 if (security_locked_down(LOCKDOWN_DEBUGFS))
158 return -EPERM;
159
160 return 0;
161}
162
163static int open_proxy_open(struct inode *inode, struct file *filp)
164{
165 struct dentry *dentry = F_DENTRY(filp);
166 const struct file_operations *real_fops = NULL;
167 int r;
168
169 r = debugfs_file_get(dentry);
170 if (r)
171 return r == -EIO ? -ENOENT : r;
172
173 real_fops = debugfs_real_fops(filp);
174
175 r = debugfs_locked_down(inode, filp, real_fops);
176 if (r)
177 goto out;
178
179 if (!fops_get(real_fops)) {
180#ifdef CONFIG_MODULES
181 if (real_fops->owner &&
182 real_fops->owner->state == MODULE_STATE_GOING) {
183 r = -ENXIO;
184 goto out;
185 }
186#endif
187
188 /* Huh? Module did not clean up after itself at exit? */
189 WARN(1, "debugfs file owner did not clean up at exit: %pd",
190 dentry);
191 r = -ENXIO;
192 goto out;
193 }
194 replace_fops(filp, real_fops);
195
196 if (real_fops->open)
197 r = real_fops->open(inode, filp);
198
199out:
200 debugfs_file_put(dentry);
201 return r;
202}
203
204const struct file_operations debugfs_open_proxy_file_operations = {
205 .open = open_proxy_open,
206};
207
208#define PROTO(args...) args
209#define ARGS(args...) args
210
211#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
212static ret_type full_proxy_ ## name(proto) \
213{ \
214 struct dentry *dentry = F_DENTRY(filp); \
215 const struct file_operations *real_fops; \
216 ret_type r; \
217 \
218 r = debugfs_file_get(dentry); \
219 if (unlikely(r)) \
220 return r; \
221 real_fops = debugfs_real_fops(filp); \
222 r = real_fops->name(args); \
223 debugfs_file_put(dentry); \
224 return r; \
225}
226
227FULL_PROXY_FUNC(llseek, loff_t, filp,
228 PROTO(struct file *filp, loff_t offset, int whence),
229 ARGS(filp, offset, whence));
230
231FULL_PROXY_FUNC(read, ssize_t, filp,
232 PROTO(struct file *filp, char __user *buf, size_t size,
233 loff_t *ppos),
234 ARGS(filp, buf, size, ppos));
235
236FULL_PROXY_FUNC(write, ssize_t, filp,
237 PROTO(struct file *filp, const char __user *buf, size_t size,
238 loff_t *ppos),
239 ARGS(filp, buf, size, ppos));
240
241FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
242 PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
243 ARGS(filp, cmd, arg));
244
245static __poll_t full_proxy_poll(struct file *filp,
246 struct poll_table_struct *wait)
247{
248 struct dentry *dentry = F_DENTRY(filp);
249 __poll_t r = 0;
250 const struct file_operations *real_fops;
251
252 if (debugfs_file_get(dentry))
253 return EPOLLHUP;
254
255 real_fops = debugfs_real_fops(filp);
256 r = real_fops->poll(filp, wait);
257 debugfs_file_put(dentry);
258 return r;
259}
260
261static int full_proxy_release(struct inode *inode, struct file *filp)
262{
263 const struct dentry *dentry = F_DENTRY(filp);
264 const struct file_operations *real_fops = debugfs_real_fops(filp);
265 const struct file_operations *proxy_fops = filp->f_op;
266 int r = 0;
267
268 /*
269 * We must not protect this against removal races here: the
270 * original releaser should be called unconditionally in order
271 * not to leak any resources. Releasers must not assume that
272 * ->i_private is still being meaningful here.
273 */
274 if (real_fops->release)
275 r = real_fops->release(inode, filp);
276
277 replace_fops(filp, d_inode(dentry)->i_fop);
278 kfree(proxy_fops);
279 fops_put(real_fops);
280 return r;
281}
282
283static void __full_proxy_fops_init(struct file_operations *proxy_fops,
284 const struct file_operations *real_fops)
285{
286 proxy_fops->release = full_proxy_release;
287 if (real_fops->llseek)
288 proxy_fops->llseek = full_proxy_llseek;
289 if (real_fops->read)
290 proxy_fops->read = full_proxy_read;
291 if (real_fops->write)
292 proxy_fops->write = full_proxy_write;
293 if (real_fops->poll)
294 proxy_fops->poll = full_proxy_poll;
295 if (real_fops->unlocked_ioctl)
296 proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
297}
298
299static int full_proxy_open(struct inode *inode, struct file *filp)
300{
301 struct dentry *dentry = F_DENTRY(filp);
302 const struct file_operations *real_fops = NULL;
303 struct file_operations *proxy_fops = NULL;
304 int r;
305
306 r = debugfs_file_get(dentry);
307 if (r)
308 return r == -EIO ? -ENOENT : r;
309
310 real_fops = debugfs_real_fops(filp);
311
312 r = debugfs_locked_down(inode, filp, real_fops);
313 if (r)
314 goto out;
315
316 if (!fops_get(real_fops)) {
317#ifdef CONFIG_MODULES
318 if (real_fops->owner &&
319 real_fops->owner->state == MODULE_STATE_GOING) {
320 r = -ENXIO;
321 goto out;
322 }
323#endif
324
325 /* Huh? Module did not cleanup after itself at exit? */
326 WARN(1, "debugfs file owner did not clean up at exit: %pd",
327 dentry);
328 r = -ENXIO;
329 goto out;
330 }
331
332 proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
333 if (!proxy_fops) {
334 r = -ENOMEM;
335 goto free_proxy;
336 }
337 __full_proxy_fops_init(proxy_fops, real_fops);
338 replace_fops(filp, proxy_fops);
339
340 if (real_fops->open) {
341 r = real_fops->open(inode, filp);
342 if (r) {
343 replace_fops(filp, d_inode(dentry)->i_fop);
344 goto free_proxy;
345 } else if (filp->f_op != proxy_fops) {
346 /* No protection against file removal anymore. */
347 WARN(1, "debugfs file owner replaced proxy fops: %pd",
348 dentry);
349 goto free_proxy;
350 }
351 }
352
353 goto out;
354free_proxy:
355 kfree(proxy_fops);
356 fops_put(real_fops);
357out:
358 debugfs_file_put(dentry);
359 return r;
360}
361
362const struct file_operations debugfs_full_proxy_file_operations = {
363 .open = full_proxy_open,
364};
365
366ssize_t debugfs_attr_read(struct file *file, char __user *buf,
367 size_t len, loff_t *ppos)
368{
369 struct dentry *dentry = F_DENTRY(file);
370 ssize_t ret;
371
372 ret = debugfs_file_get(dentry);
373 if (unlikely(ret))
374 return ret;
375 ret = simple_attr_read(file, buf, len, ppos);
376 debugfs_file_put(dentry);
377 return ret;
378}
379EXPORT_SYMBOL_GPL(debugfs_attr_read);
380
381static ssize_t debugfs_attr_write_xsigned(struct file *file, const char __user *buf,
382 size_t len, loff_t *ppos, bool is_signed)
383{
384 struct dentry *dentry = F_DENTRY(file);
385 ssize_t ret;
386
387 ret = debugfs_file_get(dentry);
388 if (unlikely(ret))
389 return ret;
390 if (is_signed)
391 ret = simple_attr_write_signed(file, buf, len, ppos);
392 else
393 ret = simple_attr_write(file, buf, len, ppos);
394 debugfs_file_put(dentry);
395 return ret;
396}
397
398ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
399 size_t len, loff_t *ppos)
400{
401 return debugfs_attr_write_xsigned(file, buf, len, ppos, false);
402}
403EXPORT_SYMBOL_GPL(debugfs_attr_write);
404
405ssize_t debugfs_attr_write_signed(struct file *file, const char __user *buf,
406 size_t len, loff_t *ppos)
407{
408 return debugfs_attr_write_xsigned(file, buf, len, ppos, true);
409}
410EXPORT_SYMBOL_GPL(debugfs_attr_write_signed);
411
412static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
413 struct dentry *parent, void *value,
414 const struct file_operations *fops,
415 const struct file_operations *fops_ro,
416 const struct file_operations *fops_wo)
417{
418 /* if there are no write bits set, make read only */
419 if (!(mode & S_IWUGO))
420 return debugfs_create_file_unsafe(name, mode, parent, value,
421 fops_ro);
422 /* if there are no read bits set, make write only */
423 if (!(mode & S_IRUGO))
424 return debugfs_create_file_unsafe(name, mode, parent, value,
425 fops_wo);
426
427 return debugfs_create_file_unsafe(name, mode, parent, value, fops);
428}
429
430static int debugfs_u8_set(void *data, u64 val)
431{
432 *(u8 *)data = val;
433 return 0;
434}
435static int debugfs_u8_get(void *data, u64 *val)
436{
437 *val = *(u8 *)data;
438 return 0;
439}
440DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
441DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
442DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
443
444/**
445 * debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
446 * @name: a pointer to a string containing the name of the file to create.
447 * @mode: the permission that the file should have
448 * @parent: a pointer to the parent dentry for this file. This should be a
449 * directory dentry if set. If this parameter is %NULL, then the
450 * file will be created in the root of the debugfs filesystem.
451 * @value: a pointer to the variable that the file should read to and write
452 * from.
453 *
454 * This function creates a file in debugfs with the given name that
455 * contains the value of the variable @value. If the @mode variable is so
456 * set, it can be read from, and written to.
457 */
458void debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent,
459 u8 *value)
460{
461 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
462 &fops_u8_ro, &fops_u8_wo);
463}
464EXPORT_SYMBOL_GPL(debugfs_create_u8);
465
466static int debugfs_u16_set(void *data, u64 val)
467{
468 *(u16 *)data = val;
469 return 0;
470}
471static int debugfs_u16_get(void *data, u64 *val)
472{
473 *val = *(u16 *)data;
474 return 0;
475}
476DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
477DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
478DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
479
480/**
481 * debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
482 * @name: a pointer to a string containing the name of the file to create.
483 * @mode: the permission that the file should have
484 * @parent: a pointer to the parent dentry for this file. This should be a
485 * directory dentry if set. If this parameter is %NULL, then the
486 * file will be created in the root of the debugfs filesystem.
487 * @value: a pointer to the variable that the file should read to and write
488 * from.
489 *
490 * This function creates a file in debugfs with the given name that
491 * contains the value of the variable @value. If the @mode variable is so
492 * set, it can be read from, and written to.
493 */
494void debugfs_create_u16(const char *name, umode_t mode, struct dentry *parent,
495 u16 *value)
496{
497 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
498 &fops_u16_ro, &fops_u16_wo);
499}
500EXPORT_SYMBOL_GPL(debugfs_create_u16);
501
502static int debugfs_u32_set(void *data, u64 val)
503{
504 *(u32 *)data = val;
505 return 0;
506}
507static int debugfs_u32_get(void *data, u64 *val)
508{
509 *val = *(u32 *)data;
510 return 0;
511}
512DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
513DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
514DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
515
516/**
517 * debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
518 * @name: a pointer to a string containing the name of the file to create.
519 * @mode: the permission that the file should have
520 * @parent: a pointer to the parent dentry for this file. This should be a
521 * directory dentry if set. If this parameter is %NULL, then the
522 * file will be created in the root of the debugfs filesystem.
523 * @value: a pointer to the variable that the file should read to and write
524 * from.
525 *
526 * This function creates a file in debugfs with the given name that
527 * contains the value of the variable @value. If the @mode variable is so
528 * set, it can be read from, and written to.
529 */
530void debugfs_create_u32(const char *name, umode_t mode, struct dentry *parent,
531 u32 *value)
532{
533 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
534 &fops_u32_ro, &fops_u32_wo);
535}
536EXPORT_SYMBOL_GPL(debugfs_create_u32);
537
538static int debugfs_u64_set(void *data, u64 val)
539{
540 *(u64 *)data = val;
541 return 0;
542}
543
544static int debugfs_u64_get(void *data, u64 *val)
545{
546 *val = *(u64 *)data;
547 return 0;
548}
549DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
550DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
551DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
552
553/**
554 * debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
555 * @name: a pointer to a string containing the name of the file to create.
556 * @mode: the permission that the file should have
557 * @parent: a pointer to the parent dentry for this file. This should be a
558 * directory dentry if set. If this parameter is %NULL, then the
559 * file will be created in the root of the debugfs filesystem.
560 * @value: a pointer to the variable that the file should read to and write
561 * from.
562 *
563 * This function creates a file in debugfs with the given name that
564 * contains the value of the variable @value. If the @mode variable is so
565 * set, it can be read from, and written to.
566 */
567void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
568 u64 *value)
569{
570 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
571 &fops_u64_ro, &fops_u64_wo);
572}
573EXPORT_SYMBOL_GPL(debugfs_create_u64);
574
575static int debugfs_ulong_set(void *data, u64 val)
576{
577 *(unsigned long *)data = val;
578 return 0;
579}
580
581static int debugfs_ulong_get(void *data, u64 *val)
582{
583 *val = *(unsigned long *)data;
584 return 0;
585}
586DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
587 "%llu\n");
588DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
589DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
590
591/**
592 * debugfs_create_ulong - create a debugfs file that is used to read and write
593 * an unsigned long value.
594 * @name: a pointer to a string containing the name of the file to create.
595 * @mode: the permission that the file should have
596 * @parent: a pointer to the parent dentry for this file. This should be a
597 * directory dentry if set. If this parameter is %NULL, then the
598 * file will be created in the root of the debugfs filesystem.
599 * @value: a pointer to the variable that the file should read to and write
600 * from.
601 *
602 * This function creates a file in debugfs with the given name that
603 * contains the value of the variable @value. If the @mode variable is so
604 * set, it can be read from, and written to.
605 */
606void debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent,
607 unsigned long *value)
608{
609 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong,
610 &fops_ulong_ro, &fops_ulong_wo);
611}
612EXPORT_SYMBOL_GPL(debugfs_create_ulong);
613
614DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
615DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
616DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
617
618DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
619 "0x%04llx\n");
620DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
621DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
622
623DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
624 "0x%08llx\n");
625DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
626DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
627
628DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
629 "0x%016llx\n");
630DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
631DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
632
633/*
634 * debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
635 *
636 * These functions are exactly the same as the above functions (but use a hex
637 * output for the decimal challenged). For details look at the above unsigned
638 * decimal functions.
639 */
640
641/**
642 * debugfs_create_x8 - create a debugfs file that is used to read and write an unsigned 8-bit value
643 * @name: a pointer to a string containing the name of the file to create.
644 * @mode: the permission that the file should have
645 * @parent: a pointer to the parent dentry for this file. This should be a
646 * directory dentry if set. If this parameter is %NULL, then the
647 * file will be created in the root of the debugfs filesystem.
648 * @value: a pointer to the variable that the file should read to and write
649 * from.
650 */
651void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
652 u8 *value)
653{
654 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
655 &fops_x8_ro, &fops_x8_wo);
656}
657EXPORT_SYMBOL_GPL(debugfs_create_x8);
658
659/**
660 * debugfs_create_x16 - create a debugfs file that is used to read and write an unsigned 16-bit value
661 * @name: a pointer to a string containing the name of the file to create.
662 * @mode: the permission that the file should have
663 * @parent: a pointer to the parent dentry for this file. This should be a
664 * directory dentry if set. If this parameter is %NULL, then the
665 * file will be created in the root of the debugfs filesystem.
666 * @value: a pointer to the variable that the file should read to and write
667 * from.
668 */
669void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
670 u16 *value)
671{
672 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
673 &fops_x16_ro, &fops_x16_wo);
674}
675EXPORT_SYMBOL_GPL(debugfs_create_x16);
676
677/**
678 * debugfs_create_x32 - create a debugfs file that is used to read and write an unsigned 32-bit value
679 * @name: a pointer to a string containing the name of the file to create.
680 * @mode: the permission that the file should have
681 * @parent: a pointer to the parent dentry for this file. This should be a
682 * directory dentry if set. If this parameter is %NULL, then the
683 * file will be created in the root of the debugfs filesystem.
684 * @value: a pointer to the variable that the file should read to and write
685 * from.
686 */
687void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
688 u32 *value)
689{
690 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
691 &fops_x32_ro, &fops_x32_wo);
692}
693EXPORT_SYMBOL_GPL(debugfs_create_x32);
694
695/**
696 * debugfs_create_x64 - create a debugfs file that is used to read and write an unsigned 64-bit value
697 * @name: a pointer to a string containing the name of the file to create.
698 * @mode: the permission that the file should have
699 * @parent: a pointer to the parent dentry for this file. This should be a
700 * directory dentry if set. If this parameter is %NULL, then the
701 * file will be created in the root of the debugfs filesystem.
702 * @value: a pointer to the variable that the file should read to and write
703 * from.
704 */
705void debugfs_create_x64(const char *name, umode_t mode, struct dentry *parent,
706 u64 *value)
707{
708 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64,
709 &fops_x64_ro, &fops_x64_wo);
710}
711EXPORT_SYMBOL_GPL(debugfs_create_x64);
712
713
714static int debugfs_size_t_set(void *data, u64 val)
715{
716 *(size_t *)data = val;
717 return 0;
718}
719static int debugfs_size_t_get(void *data, u64 *val)
720{
721 *val = *(size_t *)data;
722 return 0;
723}
724DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
725 "%llu\n"); /* %llu and %zu are more or less the same */
726DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
727DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
728
729/**
730 * debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
731 * @name: a pointer to a string containing the name of the file to create.
732 * @mode: the permission that the file should have
733 * @parent: a pointer to the parent dentry for this file. This should be a
734 * directory dentry if set. If this parameter is %NULL, then the
735 * file will be created in the root of the debugfs filesystem.
736 * @value: a pointer to the variable that the file should read to and write
737 * from.
738 */
739void debugfs_create_size_t(const char *name, umode_t mode,
740 struct dentry *parent, size_t *value)
741{
742 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_size_t,
743 &fops_size_t_ro, &fops_size_t_wo);
744}
745EXPORT_SYMBOL_GPL(debugfs_create_size_t);
746
747static int debugfs_atomic_t_set(void *data, u64 val)
748{
749 atomic_set((atomic_t *)data, val);
750 return 0;
751}
752static int debugfs_atomic_t_get(void *data, u64 *val)
753{
754 *val = atomic_read((atomic_t *)data);
755 return 0;
756}
757DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get,
758 debugfs_atomic_t_set, "%lld\n");
759DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
760 "%lld\n");
761DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
762 "%lld\n");
763
764/**
765 * debugfs_create_atomic_t - create a debugfs file that is used to read and
766 * write an atomic_t value
767 * @name: a pointer to a string containing the name of the file to create.
768 * @mode: the permission that the file should have
769 * @parent: a pointer to the parent dentry for this file. This should be a
770 * directory dentry if set. If this parameter is %NULL, then the
771 * file will be created in the root of the debugfs filesystem.
772 * @value: a pointer to the variable that the file should read to and write
773 * from.
774 */
775void debugfs_create_atomic_t(const char *name, umode_t mode,
776 struct dentry *parent, atomic_t *value)
777{
778 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_atomic_t,
779 &fops_atomic_t_ro, &fops_atomic_t_wo);
780}
781EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
782
783ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
784 size_t count, loff_t *ppos)
785{
786 char buf[2];
787 bool val;
788 int r;
789 struct dentry *dentry = F_DENTRY(file);
790
791 r = debugfs_file_get(dentry);
792 if (unlikely(r))
793 return r;
794 val = *(bool *)file->private_data;
795 debugfs_file_put(dentry);
796
797 if (val)
798 buf[0] = 'Y';
799 else
800 buf[0] = 'N';
801 buf[1] = '\n';
802 return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
803}
804EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
805
806ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
807 size_t count, loff_t *ppos)
808{
809 bool bv;
810 int r;
811 bool *val = file->private_data;
812 struct dentry *dentry = F_DENTRY(file);
813
814 r = kstrtobool_from_user(user_buf, count, &bv);
815 if (!r) {
816 r = debugfs_file_get(dentry);
817 if (unlikely(r))
818 return r;
819 *val = bv;
820 debugfs_file_put(dentry);
821 }
822
823 return count;
824}
825EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
826
827static const struct file_operations fops_bool = {
828 .read = debugfs_read_file_bool,
829 .write = debugfs_write_file_bool,
830 .open = simple_open,
831 .llseek = default_llseek,
832};
833
834static const struct file_operations fops_bool_ro = {
835 .read = debugfs_read_file_bool,
836 .open = simple_open,
837 .llseek = default_llseek,
838};
839
840static const struct file_operations fops_bool_wo = {
841 .write = debugfs_write_file_bool,
842 .open = simple_open,
843 .llseek = default_llseek,
844};
845
846/**
847 * debugfs_create_bool - create a debugfs file that is used to read and write a boolean value
848 * @name: a pointer to a string containing the name of the file to create.
849 * @mode: the permission that the file should have
850 * @parent: a pointer to the parent dentry for this file. This should be a
851 * directory dentry if set. If this parameter is %NULL, then the
852 * file will be created in the root of the debugfs filesystem.
853 * @value: a pointer to the variable that the file should read to and write
854 * from.
855 *
856 * This function creates a file in debugfs with the given name that
857 * contains the value of the variable @value. If the @mode variable is so
858 * set, it can be read from, and written to.
859 */
860void debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent,
861 bool *value)
862{
863 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
864 &fops_bool_ro, &fops_bool_wo);
865}
866EXPORT_SYMBOL_GPL(debugfs_create_bool);
867
868ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
869 size_t count, loff_t *ppos)
870{
871 struct dentry *dentry = F_DENTRY(file);
872 char *str, *copy = NULL;
873 int copy_len, len;
874 ssize_t ret;
875
876 ret = debugfs_file_get(dentry);
877 if (unlikely(ret))
878 return ret;
879
880 str = *(char **)file->private_data;
881 len = strlen(str) + 1;
882 copy = kmalloc(len, GFP_KERNEL);
883 if (!copy) {
884 debugfs_file_put(dentry);
885 return -ENOMEM;
886 }
887
888 copy_len = strscpy(copy, str, len);
889 debugfs_file_put(dentry);
890 if (copy_len < 0) {
891 kfree(copy);
892 return copy_len;
893 }
894
895 copy[copy_len] = '\n';
896
897 ret = simple_read_from_buffer(user_buf, count, ppos, copy, len);
898 kfree(copy);
899
900 return ret;
901}
902
903static ssize_t debugfs_write_file_str(struct file *file, const char __user *user_buf,
904 size_t count, loff_t *ppos)
905{
906 /* This is really only for read-only strings */
907 return -EINVAL;
908}
909
910static const struct file_operations fops_str = {
911 .read = debugfs_read_file_str,
912 .write = debugfs_write_file_str,
913 .open = simple_open,
914 .llseek = default_llseek,
915};
916
917static const struct file_operations fops_str_ro = {
918 .read = debugfs_read_file_str,
919 .open = simple_open,
920 .llseek = default_llseek,
921};
922
923static const struct file_operations fops_str_wo = {
924 .write = debugfs_write_file_str,
925 .open = simple_open,
926 .llseek = default_llseek,
927};
928
929/**
930 * debugfs_create_str - create a debugfs file that is used to read and write a string value
931 * @name: a pointer to a string containing the name of the file to create.
932 * @mode: the permission that the file should have
933 * @parent: a pointer to the parent dentry for this file. This should be a
934 * directory dentry if set. If this parameter is %NULL, then the
935 * file will be created in the root of the debugfs filesystem.
936 * @value: a pointer to the variable that the file should read to and write
937 * from.
938 *
939 * This function creates a file in debugfs with the given name that
940 * contains the value of the variable @value. If the @mode variable is so
941 * set, it can be read from, and written to.
942 *
943 * This function will return a pointer to a dentry if it succeeds. This
944 * pointer must be passed to the debugfs_remove() function when the file is
945 * to be removed (no automatic cleanup happens if your module is unloaded,
946 * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be
947 * returned.
948 *
949 * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
950 * be returned.
951 */
952void debugfs_create_str(const char *name, umode_t mode,
953 struct dentry *parent, char **value)
954{
955 debugfs_create_mode_unsafe(name, mode, parent, value, &fops_str,
956 &fops_str_ro, &fops_str_wo);
957}
958
959static ssize_t read_file_blob(struct file *file, char __user *user_buf,
960 size_t count, loff_t *ppos)
961{
962 struct debugfs_blob_wrapper *blob = file->private_data;
963 struct dentry *dentry = F_DENTRY(file);
964 ssize_t r;
965
966 r = debugfs_file_get(dentry);
967 if (unlikely(r))
968 return r;
969 r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
970 blob->size);
971 debugfs_file_put(dentry);
972 return r;
973}
974
975static const struct file_operations fops_blob = {
976 .read = read_file_blob,
977 .open = simple_open,
978 .llseek = default_llseek,
979};
980
981/**
982 * debugfs_create_blob - create a debugfs file that is used to read a binary blob
983 * @name: a pointer to a string containing the name of the file to create.
984 * @mode: the read permission that the file should have (other permissions are
985 * masked out)
986 * @parent: a pointer to the parent dentry for this file. This should be a
987 * directory dentry if set. If this parameter is %NULL, then the
988 * file will be created in the root of the debugfs filesystem.
989 * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer
990 * to the blob data and the size of the data.
991 *
992 * This function creates a file in debugfs with the given name that exports
993 * @blob->data as a binary blob. If the @mode variable is so set it can be
994 * read from. Writing is not supported.
995 *
996 * This function will return a pointer to a dentry if it succeeds. This
997 * pointer must be passed to the debugfs_remove() function when the file is
998 * to be removed (no automatic cleanup happens if your module is unloaded,
999 * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be
1000 * returned.
1001 *
1002 * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
1003 * be returned.
1004 */
1005struct dentry *debugfs_create_blob(const char *name, umode_t mode,
1006 struct dentry *parent,
1007 struct debugfs_blob_wrapper *blob)
1008{
1009 return debugfs_create_file_unsafe(name, mode & 0444, parent, blob, &fops_blob);
1010}
1011EXPORT_SYMBOL_GPL(debugfs_create_blob);
1012
1013static size_t u32_format_array(char *buf, size_t bufsize,
1014 u32 *array, int array_size)
1015{
1016 size_t ret = 0;
1017
1018 while (--array_size >= 0) {
1019 size_t len;
1020 char term = array_size ? ' ' : '\n';
1021
1022 len = snprintf(buf, bufsize, "%u%c", *array++, term);
1023 ret += len;
1024
1025 buf += len;
1026 bufsize -= len;
1027 }
1028 return ret;
1029}
1030
1031static int u32_array_open(struct inode *inode, struct file *file)
1032{
1033 struct debugfs_u32_array *data = inode->i_private;
1034 int size, elements = data->n_elements;
1035 char *buf;
1036
1037 /*
1038 * Max size:
1039 * - 10 digits + ' '/'\n' = 11 bytes per number
1040 * - terminating NUL character
1041 */
1042 size = elements*11;
1043 buf = kmalloc(size+1, GFP_KERNEL);
1044 if (!buf)
1045 return -ENOMEM;
1046 buf[size] = 0;
1047
1048 file->private_data = buf;
1049 u32_format_array(buf, size, data->array, data->n_elements);
1050
1051 return nonseekable_open(inode, file);
1052}
1053
1054static ssize_t u32_array_read(struct file *file, char __user *buf, size_t len,
1055 loff_t *ppos)
1056{
1057 size_t size = strlen(file->private_data);
1058
1059 return simple_read_from_buffer(buf, len, ppos,
1060 file->private_data, size);
1061}
1062
1063static int u32_array_release(struct inode *inode, struct file *file)
1064{
1065 kfree(file->private_data);
1066
1067 return 0;
1068}
1069
1070static const struct file_operations u32_array_fops = {
1071 .owner = THIS_MODULE,
1072 .open = u32_array_open,
1073 .release = u32_array_release,
1074 .read = u32_array_read,
1075 .llseek = no_llseek,
1076};
1077
1078/**
1079 * debugfs_create_u32_array - create a debugfs file that is used to read u32
1080 * array.
1081 * @name: a pointer to a string containing the name of the file to create.
1082 * @mode: the permission that the file should have.
1083 * @parent: a pointer to the parent dentry for this file. This should be a
1084 * directory dentry if set. If this parameter is %NULL, then the
1085 * file will be created in the root of the debugfs filesystem.
1086 * @array: wrapper struct containing data pointer and size of the array.
1087 *
1088 * This function creates a file in debugfs with the given name that exports
1089 * @array as data. If the @mode variable is so set it can be read from.
1090 * Writing is not supported. Seek within the file is also not supported.
1091 * Once array is created its size can not be changed.
1092 */
1093void debugfs_create_u32_array(const char *name, umode_t mode,
1094 struct dentry *parent,
1095 struct debugfs_u32_array *array)
1096{
1097 debugfs_create_file_unsafe(name, mode, parent, array, &u32_array_fops);
1098}
1099EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
1100
1101#ifdef CONFIG_HAS_IOMEM
1102
1103/*
1104 * The regset32 stuff is used to print 32-bit registers using the
1105 * seq_file utilities. We offer printing a register set in an already-opened
1106 * sequential file or create a debugfs file that only prints a regset32.
1107 */
1108
1109/**
1110 * debugfs_print_regs32 - use seq_print to describe a set of registers
1111 * @s: the seq_file structure being used to generate output
1112 * @regs: an array if struct debugfs_reg32 structures
1113 * @nregs: the length of the above array
1114 * @base: the base address to be used in reading the registers
1115 * @prefix: a string to be prefixed to every output line
1116 *
1117 * This function outputs a text block describing the current values of
1118 * some 32-bit hardware registers. It is meant to be used within debugfs
1119 * files based on seq_file that need to show registers, intermixed with other
1120 * information. The prefix argument may be used to specify a leading string,
1121 * because some peripherals have several blocks of identical registers,
1122 * for example configuration of dma channels
1123 */
1124void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
1125 int nregs, void __iomem *base, char *prefix)
1126{
1127 int i;
1128
1129 for (i = 0; i < nregs; i++, regs++) {
1130 if (prefix)
1131 seq_printf(s, "%s", prefix);
1132 seq_printf(s, "%s = 0x%08x\n", regs->name,
1133 readl(base + regs->offset));
1134 if (seq_has_overflowed(s))
1135 break;
1136 }
1137}
1138EXPORT_SYMBOL_GPL(debugfs_print_regs32);
1139
1140static int debugfs_regset32_show(struct seq_file *s, void *data)
1141{
1142 struct debugfs_regset32 *regset = s->private;
1143
1144 if (regset->dev)
1145 pm_runtime_get_sync(regset->dev);
1146
1147 debugfs_print_regs32(s, regset->regs, regset->nregs, regset->base, "");
1148
1149 if (regset->dev)
1150 pm_runtime_put(regset->dev);
1151
1152 return 0;
1153}
1154
1155DEFINE_SHOW_ATTRIBUTE(debugfs_regset32);
1156
1157/**
1158 * debugfs_create_regset32 - create a debugfs file that returns register values
1159 * @name: a pointer to a string containing the name of the file to create.
1160 * @mode: the permission that the file should have
1161 * @parent: a pointer to the parent dentry for this file. This should be a
1162 * directory dentry if set. If this parameter is %NULL, then the
1163 * file will be created in the root of the debugfs filesystem.
1164 * @regset: a pointer to a struct debugfs_regset32, which contains a pointer
1165 * to an array of register definitions, the array size and the base
1166 * address where the register bank is to be found.
1167 *
1168 * This function creates a file in debugfs with the given name that reports
1169 * the names and values of a set of 32-bit registers. If the @mode variable
1170 * is so set it can be read from. Writing is not supported.
1171 */
1172void debugfs_create_regset32(const char *name, umode_t mode,
1173 struct dentry *parent,
1174 struct debugfs_regset32 *regset)
1175{
1176 debugfs_create_file(name, mode, parent, regset, &debugfs_regset32_fops);
1177}
1178EXPORT_SYMBOL_GPL(debugfs_create_regset32);
1179
1180#endif /* CONFIG_HAS_IOMEM */
1181
1182struct debugfs_devm_entry {
1183 int (*read)(struct seq_file *seq, void *data);
1184 struct device *dev;
1185};
1186
1187static int debugfs_devm_entry_open(struct inode *inode, struct file *f)
1188{
1189 struct debugfs_devm_entry *entry = inode->i_private;
1190
1191 return single_open(f, entry->read, entry->dev);
1192}
1193
1194static const struct file_operations debugfs_devm_entry_ops = {
1195 .owner = THIS_MODULE,
1196 .open = debugfs_devm_entry_open,
1197 .release = single_release,
1198 .read = seq_read,
1199 .llseek = seq_lseek
1200};
1201
1202/**
1203 * debugfs_create_devm_seqfile - create a debugfs file that is bound to device.
1204 *
1205 * @dev: device related to this debugfs file.
1206 * @name: name of the debugfs file.
1207 * @parent: a pointer to the parent dentry for this file. This should be a
1208 * directory dentry if set. If this parameter is %NULL, then the
1209 * file will be created in the root of the debugfs filesystem.
1210 * @read_fn: function pointer called to print the seq_file content.
1211 */
1212void debugfs_create_devm_seqfile(struct device *dev, const char *name,
1213 struct dentry *parent,
1214 int (*read_fn)(struct seq_file *s, void *data))
1215{
1216 struct debugfs_devm_entry *entry;
1217
1218 if (IS_ERR(parent))
1219 return;
1220
1221 entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
1222 if (!entry)
1223 return;
1224
1225 entry->read = read_fn;
1226 entry->dev = dev;
1227
1228 debugfs_create_file(name, S_IRUGO, parent, entry,
1229 &debugfs_devm_entry_ops);
1230}
1231EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);