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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/*
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);