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