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