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