xref: /openbmc/linux/fs/debugfs/file.c (revision cf26e043)
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  
27  struct poll_table_struct;
28  
29  static ssize_t default_read_file(struct file *file, char __user *buf,
30  				 size_t count, loff_t *ppos)
31  {
32  	return 0;
33  }
34  
35  static 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  
41  const 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  
50  const 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  }
65  EXPORT_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   */
82  int 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  }
121  EXPORT_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   */
132  void 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  }
139  EXPORT_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   */
146  static 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  
163  static 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  
199  out:
200  	debugfs_file_put(dentry);
201  	return r;
202  }
203  
204  const 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)		\
212  static 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  
227  FULL_PROXY_FUNC(llseek, loff_t, filp,
228  		PROTO(struct file *filp, loff_t offset, int whence),
229  		ARGS(filp, offset, whence));
230  
231  FULL_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  
236  FULL_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  
241  FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
242  		PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
243  		ARGS(filp, cmd, arg));
244  
245  static __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  
261  static 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  
283  static 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  
299  static 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;
354  free_proxy:
355  	kfree(proxy_fops);
356  	fops_put(real_fops);
357  out:
358  	debugfs_file_put(dentry);
359  	return r;
360  }
361  
362  const struct file_operations debugfs_full_proxy_file_operations = {
363  	.open = full_proxy_open,
364  };
365  
366  ssize_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  }
379  EXPORT_SYMBOL_GPL(debugfs_attr_read);
380  
381  static 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  
398  ssize_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  }
403  EXPORT_SYMBOL_GPL(debugfs_attr_write);
404  
405  ssize_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  }
410  EXPORT_SYMBOL_GPL(debugfs_attr_write_signed);
411  
412  static 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  
430  static int debugfs_u8_set(void *data, u64 val)
431  {
432  	*(u8 *)data = val;
433  	return 0;
434  }
435  static int debugfs_u8_get(void *data, u64 *val)
436  {
437  	*val = *(u8 *)data;
438  	return 0;
439  }
440  DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
441  DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
442  DEFINE_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   */
458  void 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  }
464  EXPORT_SYMBOL_GPL(debugfs_create_u8);
465  
466  static int debugfs_u16_set(void *data, u64 val)
467  {
468  	*(u16 *)data = val;
469  	return 0;
470  }
471  static int debugfs_u16_get(void *data, u64 *val)
472  {
473  	*val = *(u16 *)data;
474  	return 0;
475  }
476  DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
477  DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
478  DEFINE_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   */
494  void 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  }
500  EXPORT_SYMBOL_GPL(debugfs_create_u16);
501  
502  static int debugfs_u32_set(void *data, u64 val)
503  {
504  	*(u32 *)data = val;
505  	return 0;
506  }
507  static int debugfs_u32_get(void *data, u64 *val)
508  {
509  	*val = *(u32 *)data;
510  	return 0;
511  }
512  DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
513  DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
514  DEFINE_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   */
530  void 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  }
536  EXPORT_SYMBOL_GPL(debugfs_create_u32);
537  
538  static int debugfs_u64_set(void *data, u64 val)
539  {
540  	*(u64 *)data = val;
541  	return 0;
542  }
543  
544  static int debugfs_u64_get(void *data, u64 *val)
545  {
546  	*val = *(u64 *)data;
547  	return 0;
548  }
549  DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
550  DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
551  DEFINE_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   */
567  void 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  }
573  EXPORT_SYMBOL_GPL(debugfs_create_u64);
574  
575  static int debugfs_ulong_set(void *data, u64 val)
576  {
577  	*(unsigned long *)data = val;
578  	return 0;
579  }
580  
581  static int debugfs_ulong_get(void *data, u64 *val)
582  {
583  	*val = *(unsigned long *)data;
584  	return 0;
585  }
586  DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
587  			"%llu\n");
588  DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
589  DEFINE_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   */
606  void 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  }
612  EXPORT_SYMBOL_GPL(debugfs_create_ulong);
613  
614  DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
615  DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
616  DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
617  
618  DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
619  			"0x%04llx\n");
620  DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
621  DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
622  
623  DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
624  			"0x%08llx\n");
625  DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
626  DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
627  
628  DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
629  			"0x%016llx\n");
630  DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
631  DEFINE_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   */
651  void 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  }
657  EXPORT_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   */
669  void 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  }
675  EXPORT_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   */
687  void 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  }
693  EXPORT_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   */
705  void 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  }
711  EXPORT_SYMBOL_GPL(debugfs_create_x64);
712  
713  
714  static int debugfs_size_t_set(void *data, u64 val)
715  {
716  	*(size_t *)data = val;
717  	return 0;
718  }
719  static int debugfs_size_t_get(void *data, u64 *val)
720  {
721  	*val = *(size_t *)data;
722  	return 0;
723  }
724  DEFINE_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 */
726  DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
727  DEFINE_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   */
739  void 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  }
745  EXPORT_SYMBOL_GPL(debugfs_create_size_t);
746  
747  static int debugfs_atomic_t_set(void *data, u64 val)
748  {
749  	atomic_set((atomic_t *)data, val);
750  	return 0;
751  }
752  static int debugfs_atomic_t_get(void *data, u64 *val)
753  {
754  	*val = atomic_read((atomic_t *)data);
755  	return 0;
756  }
757  DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t, debugfs_atomic_t_get,
758  			debugfs_atomic_t_set, "%lld\n");
759  DEFINE_DEBUGFS_ATTRIBUTE_SIGNED(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
760  			"%lld\n");
761  DEFINE_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   */
775  void 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  }
781  EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
782  
783  ssize_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  }
804  EXPORT_SYMBOL_GPL(debugfs_read_file_bool);
805  
806  ssize_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  }
825  EXPORT_SYMBOL_GPL(debugfs_write_file_bool);
826  
827  static 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  
834  static const struct file_operations fops_bool_ro = {
835  	.read =		debugfs_read_file_bool,
836  	.open =		simple_open,
837  	.llseek =	default_llseek,
838  };
839  
840  static 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   */
860  void 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  }
866  EXPORT_SYMBOL_GPL(debugfs_create_bool);
867  
868  ssize_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  
903  static 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  
910  static 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  
917  static const struct file_operations fops_str_ro = {
918  	.read =		debugfs_read_file_str,
919  	.open =		simple_open,
920  	.llseek =	default_llseek,
921  };
922  
923  static 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   */
952  void 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  
959  static 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  
975  static 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   */
1005  struct 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  }
1011  EXPORT_SYMBOL_GPL(debugfs_create_blob);
1012  
1013  static 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  
1031  static 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  
1054  static 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  
1063  static int u32_array_release(struct inode *inode, struct file *file)
1064  {
1065  	kfree(file->private_data);
1066  
1067  	return 0;
1068  }
1069  
1070  static 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   */
1093  void 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  }
1099  EXPORT_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   */
1124  void 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  }
1138  EXPORT_SYMBOL_GPL(debugfs_print_regs32);
1139  
1140  static 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  
1155  DEFINE_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   */
1172  void 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  }
1178  EXPORT_SYMBOL_GPL(debugfs_create_regset32);
1179  
1180  #endif /* CONFIG_HAS_IOMEM */
1181  
1182  struct debugfs_devm_entry {
1183  	int (*read)(struct seq_file *seq, void *data);
1184  	struct device *dev;
1185  };
1186  
1187  static 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  
1194  static 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   */
1212  void 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  }
1231  EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);
1232