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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2020
6 *
7 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
8 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
9 *
10 * Bugreports to: <Linux390@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "s390dbf"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/ctype.h>
21#include <linux/string.h>
22#include <linux/sysctl.h>
23#include <linux/uaccess.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/minmax.h>
28#include <linux/debugfs.h>
29
30#include <asm/debug.h>
31
32#define DEBUG_PROLOG_ENTRY -1
33
34#define ALL_AREAS 0 /* copy all debug areas */
35#define NO_AREAS 1 /* copy no debug areas */
36
37/* typedefs */
38
39typedef struct file_private_info {
40 loff_t offset; /* offset of last read in file */
41 int act_area; /* number of last formatted area */
42 int act_page; /* act page in given area */
43 int act_entry; /* last formatted entry (offset */
44 /* relative to beginning of last */
45 /* formatted page) */
46 size_t act_entry_offset; /* up to this offset we copied */
47 /* in last read the last formatted */
48 /* entry to userland */
49 char temp_buf[2048]; /* buffer for output */
50 debug_info_t *debug_info_org; /* original debug information */
51 debug_info_t *debug_info_snap; /* snapshot of debug information */
52 struct debug_view *view; /* used view of debug info */
53} file_private_info_t;
54
55typedef struct {
56 char *string;
57 /*
58 * This assumes that all args are converted into longs
59 * on L/390 this is the case for all types of parameter
60 * except of floats, and long long (32 bit)
61 *
62 */
63 long args[];
64} debug_sprintf_entry_t;
65
66/* internal function prototypes */
67
68static int debug_init(void);
69static ssize_t debug_output(struct file *file, char __user *user_buf,
70 size_t user_len, loff_t *offset);
71static ssize_t debug_input(struct file *file, const char __user *user_buf,
72 size_t user_len, loff_t *offset);
73static int debug_open(struct inode *inode, struct file *file);
74static int debug_close(struct inode *inode, struct file *file);
75static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76 int nr_areas, int buf_size, umode_t mode);
77static void debug_info_get(debug_info_t *);
78static void debug_info_put(debug_info_t *);
79static int debug_prolog_level_fn(debug_info_t *id,
80 struct debug_view *view, char *out_buf,
81 size_t out_buf_size);
82static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
83 struct file *file, const char __user *user_buf,
84 size_t user_buf_size, loff_t *offset);
85static int debug_prolog_pages_fn(debug_info_t *id,
86 struct debug_view *view, char *out_buf,
87 size_t out_buf_size);
88static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
89 struct file *file, const char __user *user_buf,
90 size_t user_buf_size, loff_t *offset);
91static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
92 struct file *file, const char __user *user_buf,
93 size_t user_buf_size, loff_t *offset);
94static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
95 char *out_buf, size_t out_buf_size,
96 const char *in_buf);
97static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
98 char *out_buf, size_t out_buf_size,
99 const char *inbuf);
100static void debug_areas_swap(debug_info_t *a, debug_info_t *b);
101static void debug_events_append(debug_info_t *dest, debug_info_t *src);
102
103/* globals */
104
105struct debug_view debug_hex_ascii_view = {
106 "hex_ascii",
107 NULL,
108 &debug_dflt_header_fn,
109 &debug_hex_ascii_format_fn,
110 NULL,
111 NULL
112};
113EXPORT_SYMBOL(debug_hex_ascii_view);
114
115static struct debug_view debug_level_view = {
116 "level",
117 &debug_prolog_level_fn,
118 NULL,
119 NULL,
120 &debug_input_level_fn,
121 NULL
122};
123
124static struct debug_view debug_pages_view = {
125 "pages",
126 &debug_prolog_pages_fn,
127 NULL,
128 NULL,
129 &debug_input_pages_fn,
130 NULL
131};
132
133static struct debug_view debug_flush_view = {
134 "flush",
135 NULL,
136 NULL,
137 NULL,
138 &debug_input_flush_fn,
139 NULL
140};
141
142struct debug_view debug_sprintf_view = {
143 "sprintf",
144 NULL,
145 &debug_dflt_header_fn,
146 &debug_sprintf_format_fn,
147 NULL,
148 NULL
149};
150EXPORT_SYMBOL(debug_sprintf_view);
151
152/* used by dump analysis tools to determine version of debug feature */
153static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
154
155/* static globals */
156
157static debug_info_t *debug_area_first;
158static debug_info_t *debug_area_last;
159static DEFINE_MUTEX(debug_mutex);
160
161static int initialized;
162static int debug_critical;
163
164static const struct file_operations debug_file_ops = {
165 .owner = THIS_MODULE,
166 .read = debug_output,
167 .write = debug_input,
168 .open = debug_open,
169 .release = debug_close,
170};
171
172static struct dentry *debug_debugfs_root_entry;
173
174/* functions */
175
176/*
177 * debug_areas_alloc
178 * - Debug areas are implemented as a threedimensonal array:
179 * areas[areanumber][pagenumber][pageoffset]
180 */
181
182static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
183{
184 debug_entry_t ***areas;
185 int i, j;
186
187 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL);
188 if (!areas)
189 goto fail_malloc_areas;
190 for (i = 0; i < nr_areas; i++) {
191 /* GFP_NOWARN to avoid user triggerable WARN, we handle fails */
192 areas[i] = kmalloc_array(pages_per_area,
193 sizeof(debug_entry_t *),
194 GFP_KERNEL | __GFP_NOWARN);
195 if (!areas[i])
196 goto fail_malloc_areas2;
197 for (j = 0; j < pages_per_area; j++) {
198 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
199 if (!areas[i][j]) {
200 for (j--; j >= 0 ; j--)
201 kfree(areas[i][j]);
202 kfree(areas[i]);
203 goto fail_malloc_areas2;
204 }
205 }
206 }
207 return areas;
208
209fail_malloc_areas2:
210 for (i--; i >= 0; i--) {
211 for (j = 0; j < pages_per_area; j++)
212 kfree(areas[i][j]);
213 kfree(areas[i]);
214 }
215 kfree(areas);
216fail_malloc_areas:
217 return NULL;
218}
219
220/*
221 * debug_info_alloc
222 * - alloc new debug-info
223 */
224static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
225 int nr_areas, int buf_size, int level,
226 int mode)
227{
228 debug_info_t *rc;
229
230 /* alloc everything */
231 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
232 if (!rc)
233 goto fail_malloc_rc;
234 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
235 if (!rc->active_entries)
236 goto fail_malloc_active_entries;
237 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
238 if (!rc->active_pages)
239 goto fail_malloc_active_pages;
240 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
241 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
242 if (!rc->areas)
243 goto fail_malloc_areas;
244 } else {
245 rc->areas = NULL;
246 }
247
248 /* initialize members */
249 spin_lock_init(&rc->lock);
250 rc->pages_per_area = pages_per_area;
251 rc->nr_areas = nr_areas;
252 rc->active_area = 0;
253 rc->level = level;
254 rc->buf_size = buf_size;
255 rc->entry_size = sizeof(debug_entry_t) + buf_size;
256 strscpy(rc->name, name, sizeof(rc->name));
257 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
258 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
259 refcount_set(&(rc->ref_count), 0);
260
261 return rc;
262
263fail_malloc_areas:
264 kfree(rc->active_pages);
265fail_malloc_active_pages:
266 kfree(rc->active_entries);
267fail_malloc_active_entries:
268 kfree(rc);
269fail_malloc_rc:
270 return NULL;
271}
272
273/*
274 * debug_areas_free
275 * - free all debug areas
276 */
277static void debug_areas_free(debug_info_t *db_info)
278{
279 int i, j;
280
281 if (!db_info->areas)
282 return;
283 for (i = 0; i < db_info->nr_areas; i++) {
284 for (j = 0; j < db_info->pages_per_area; j++)
285 kfree(db_info->areas[i][j]);
286 kfree(db_info->areas[i]);
287 }
288 kfree(db_info->areas);
289 db_info->areas = NULL;
290}
291
292/*
293 * debug_info_free
294 * - free memory debug-info
295 */
296static void debug_info_free(debug_info_t *db_info)
297{
298 debug_areas_free(db_info);
299 kfree(db_info->active_entries);
300 kfree(db_info->active_pages);
301 kfree(db_info);
302}
303
304/*
305 * debug_info_create
306 * - create new debug-info
307 */
308
309static debug_info_t *debug_info_create(const char *name, int pages_per_area,
310 int nr_areas, int buf_size, umode_t mode)
311{
312 debug_info_t *rc;
313
314 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
315 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
316 if (!rc)
317 goto out;
318
319 rc->mode = mode & ~S_IFMT;
320 refcount_set(&rc->ref_count, 1);
321out:
322 return rc;
323}
324
325/*
326 * debug_info_copy
327 * - copy debug-info
328 */
329static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
330{
331 unsigned long flags;
332 debug_info_t *rc;
333 int i, j;
334
335 /* get a consistent copy of the debug areas */
336 do {
337 rc = debug_info_alloc(in->name, in->pages_per_area,
338 in->nr_areas, in->buf_size, in->level, mode);
339 spin_lock_irqsave(&in->lock, flags);
340 if (!rc)
341 goto out;
342 /* has something changed in the meantime ? */
343 if ((rc->pages_per_area == in->pages_per_area) &&
344 (rc->nr_areas == in->nr_areas)) {
345 break;
346 }
347 spin_unlock_irqrestore(&in->lock, flags);
348 debug_info_free(rc);
349 } while (1);
350
351 if (mode == NO_AREAS)
352 goto out;
353
354 for (i = 0; i < in->nr_areas; i++) {
355 for (j = 0; j < in->pages_per_area; j++)
356 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
357 }
358out:
359 spin_unlock_irqrestore(&in->lock, flags);
360 return rc;
361}
362
363/*
364 * debug_info_get
365 * - increments reference count for debug-info
366 */
367static void debug_info_get(debug_info_t *db_info)
368{
369 if (db_info)
370 refcount_inc(&db_info->ref_count);
371}
372
373/*
374 * debug_info_put:
375 * - decreases reference count for debug-info and frees it if necessary
376 */
377static void debug_info_put(debug_info_t *db_info)
378{
379 if (!db_info)
380 return;
381 if (refcount_dec_and_test(&db_info->ref_count))
382 debug_info_free(db_info);
383}
384
385/*
386 * debug_format_entry:
387 * - format one debug entry and return size of formatted data
388 */
389static int debug_format_entry(file_private_info_t *p_info)
390{
391 debug_info_t *id_snap = p_info->debug_info_snap;
392 struct debug_view *view = p_info->view;
393 debug_entry_t *act_entry;
394 size_t len = 0;
395
396 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
397 /* print prolog */
398 if (view->prolog_proc) {
399 len += view->prolog_proc(id_snap, view, p_info->temp_buf,
400 sizeof(p_info->temp_buf));
401 }
402 goto out;
403 }
404 if (!id_snap->areas) /* this is true, if we have a prolog only view */
405 goto out; /* or if 'pages_per_area' is 0 */
406 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
407 [p_info->act_page] + p_info->act_entry);
408
409 if (act_entry->clock == 0LL)
410 goto out; /* empty entry */
411 if (view->header_proc) {
412 len += view->header_proc(id_snap, view, p_info->act_area,
413 act_entry, p_info->temp_buf + len,
414 sizeof(p_info->temp_buf) - len);
415 }
416 if (view->format_proc) {
417 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
418 sizeof(p_info->temp_buf) - len,
419 DEBUG_DATA(act_entry));
420 }
421out:
422 return len;
423}
424
425/*
426 * debug_next_entry:
427 * - goto next entry in p_info
428 */
429static inline int debug_next_entry(file_private_info_t *p_info)
430{
431 debug_info_t *id;
432
433 id = p_info->debug_info_snap;
434 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
435 p_info->act_entry = 0;
436 p_info->act_page = 0;
437 goto out;
438 }
439 if (!id->areas)
440 return 1;
441 p_info->act_entry += id->entry_size;
442 /* switch to next page, if we reached the end of the page */
443 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
444 /* next page */
445 p_info->act_entry = 0;
446 p_info->act_page += 1;
447 if ((p_info->act_page % id->pages_per_area) == 0) {
448 /* next area */
449 p_info->act_area++;
450 p_info->act_page = 0;
451 }
452 if (p_info->act_area >= id->nr_areas)
453 return 1;
454 }
455out:
456 return 0;
457}
458
459/*
460 * debug_output:
461 * - called for user read()
462 * - copies formatted debug entries to the user buffer
463 */
464static ssize_t debug_output(struct file *file, /* file descriptor */
465 char __user *user_buf, /* user buffer */
466 size_t len, /* length of buffer */
467 loff_t *offset) /* offset in the file */
468{
469 size_t count = 0;
470 size_t entry_offset;
471 file_private_info_t *p_info;
472
473 p_info = (file_private_info_t *) file->private_data;
474 if (*offset != p_info->offset)
475 return -EPIPE;
476 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
477 return 0;
478 entry_offset = p_info->act_entry_offset;
479 while (count < len) {
480 int formatted_line_residue;
481 int formatted_line_size;
482 int user_buf_residue;
483 size_t copy_size;
484
485 formatted_line_size = debug_format_entry(p_info);
486 formatted_line_residue = formatted_line_size - entry_offset;
487 user_buf_residue = len-count;
488 copy_size = min(user_buf_residue, formatted_line_residue);
489 if (copy_size) {
490 if (copy_to_user(user_buf + count, p_info->temp_buf
491 + entry_offset, copy_size))
492 return -EFAULT;
493 count += copy_size;
494 entry_offset += copy_size;
495 }
496 if (copy_size == formatted_line_residue) {
497 entry_offset = 0;
498 if (debug_next_entry(p_info))
499 goto out;
500 }
501 }
502out:
503 p_info->offset = *offset + count;
504 p_info->act_entry_offset = entry_offset;
505 *offset = p_info->offset;
506 return count;
507}
508
509/*
510 * debug_input:
511 * - called for user write()
512 * - calls input function of view
513 */
514static ssize_t debug_input(struct file *file, const char __user *user_buf,
515 size_t length, loff_t *offset)
516{
517 file_private_info_t *p_info;
518 int rc = 0;
519
520 mutex_lock(&debug_mutex);
521 p_info = ((file_private_info_t *) file->private_data);
522 if (p_info->view->input_proc) {
523 rc = p_info->view->input_proc(p_info->debug_info_org,
524 p_info->view, file, user_buf,
525 length, offset);
526 } else {
527 rc = -EPERM;
528 }
529 mutex_unlock(&debug_mutex);
530 return rc; /* number of input characters */
531}
532
533/*
534 * debug_open:
535 * - called for user open()
536 * - copies formatted output to private_data area of the file
537 * handle
538 */
539static int debug_open(struct inode *inode, struct file *file)
540{
541 debug_info_t *debug_info, *debug_info_snapshot;
542 file_private_info_t *p_info;
543 int i, rc = 0;
544
545 mutex_lock(&debug_mutex);
546 debug_info = file_inode(file)->i_private;
547 /* find debug view */
548 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
549 if (!debug_info->views[i])
550 continue;
551 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
552 goto found; /* found view ! */
553 }
554 /* no entry found */
555 rc = -EINVAL;
556 goto out;
557
558found:
559
560 /* Make snapshot of current debug areas to get it consistent. */
561 /* To copy all the areas is only needed, if we have a view which */
562 /* formats the debug areas. */
563
564 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
565 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
566 else
567 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
568
569 if (!debug_info_snapshot) {
570 rc = -ENOMEM;
571 goto out;
572 }
573 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
574 if (!p_info) {
575 debug_info_free(debug_info_snapshot);
576 rc = -ENOMEM;
577 goto out;
578 }
579 p_info->offset = 0;
580 p_info->debug_info_snap = debug_info_snapshot;
581 p_info->debug_info_org = debug_info;
582 p_info->view = debug_info->views[i];
583 p_info->act_area = 0;
584 p_info->act_page = 0;
585 p_info->act_entry = DEBUG_PROLOG_ENTRY;
586 p_info->act_entry_offset = 0;
587 file->private_data = p_info;
588 debug_info_get(debug_info);
589 nonseekable_open(inode, file);
590out:
591 mutex_unlock(&debug_mutex);
592 return rc;
593}
594
595/*
596 * debug_close:
597 * - called for user close()
598 * - deletes private_data area of the file handle
599 */
600static int debug_close(struct inode *inode, struct file *file)
601{
602 file_private_info_t *p_info;
603
604 p_info = (file_private_info_t *) file->private_data;
605 if (p_info->debug_info_snap)
606 debug_info_free(p_info->debug_info_snap);
607 debug_info_put(p_info->debug_info_org);
608 kfree(file->private_data);
609 return 0; /* success */
610}
611
612/* Create debugfs entries and add to internal list. */
613static void _debug_register(debug_info_t *id)
614{
615 /* create root directory */
616 id->debugfs_root_entry = debugfs_create_dir(id->name,
617 debug_debugfs_root_entry);
618
619 /* append new element to linked list */
620 if (!debug_area_first) {
621 /* first element in list */
622 debug_area_first = id;
623 id->prev = NULL;
624 } else {
625 /* append element to end of list */
626 debug_area_last->next = id;
627 id->prev = debug_area_last;
628 }
629 debug_area_last = id;
630 id->next = NULL;
631
632 debug_register_view(id, &debug_level_view);
633 debug_register_view(id, &debug_flush_view);
634 debug_register_view(id, &debug_pages_view);
635}
636
637/**
638 * debug_register_mode() - creates and initializes debug area.
639 *
640 * @name: Name of debug log (e.g. used for debugfs entry)
641 * @pages_per_area: Number of pages, which will be allocated per area
642 * @nr_areas: Number of debug areas
643 * @buf_size: Size of data area in each debug entry
644 * @mode: File mode for debugfs files. E.g. S_IRWXUGO
645 * @uid: User ID for debugfs files. Currently only 0 is supported.
646 * @gid: Group ID for debugfs files. Currently only 0 is supported.
647 *
648 * Return:
649 * - Handle for generated debug area
650 * - %NULL if register failed
651 *
652 * Allocates memory for a debug log.
653 * Must not be called within an interrupt handler.
654 */
655debug_info_t *debug_register_mode(const char *name, int pages_per_area,
656 int nr_areas, int buf_size, umode_t mode,
657 uid_t uid, gid_t gid)
658{
659 debug_info_t *rc = NULL;
660
661 /* Since debugfs currently does not support uid/gid other than root, */
662 /* we do not allow gid/uid != 0 until we get support for that. */
663 if ((uid != 0) || (gid != 0))
664 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
665 BUG_ON(!initialized);
666
667 /* create new debug_info */
668 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
669 if (rc) {
670 mutex_lock(&debug_mutex);
671 _debug_register(rc);
672 mutex_unlock(&debug_mutex);
673 } else {
674 pr_err("Registering debug feature %s failed\n", name);
675 }
676 return rc;
677}
678EXPORT_SYMBOL(debug_register_mode);
679
680/**
681 * debug_register() - creates and initializes debug area with default file mode.
682 *
683 * @name: Name of debug log (e.g. used for debugfs entry)
684 * @pages_per_area: Number of pages, which will be allocated per area
685 * @nr_areas: Number of debug areas
686 * @buf_size: Size of data area in each debug entry
687 *
688 * Return:
689 * - Handle for generated debug area
690 * - %NULL if register failed
691 *
692 * Allocates memory for a debug log.
693 * The debugfs file mode access permissions are read and write for user.
694 * Must not be called within an interrupt handler.
695 */
696debug_info_t *debug_register(const char *name, int pages_per_area,
697 int nr_areas, int buf_size)
698{
699 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
700 S_IRUSR | S_IWUSR, 0, 0);
701}
702EXPORT_SYMBOL(debug_register);
703
704/**
705 * debug_register_static() - registers a static debug area
706 *
707 * @id: Handle for static debug area
708 * @pages_per_area: Number of pages per area
709 * @nr_areas: Number of debug areas
710 *
711 * Register debug_info_t defined using DEFINE_STATIC_DEBUG_INFO.
712 *
713 * Note: This function is called automatically via an initcall generated by
714 * DEFINE_STATIC_DEBUG_INFO.
715 */
716void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas)
717{
718 unsigned long flags;
719 debug_info_t *copy;
720
721 if (!initialized) {
722 pr_err("Tried to register debug feature %s too early\n",
723 id->name);
724 return;
725 }
726
727 copy = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
728 id->level, ALL_AREAS);
729 if (!copy) {
730 pr_err("Registering debug feature %s failed\n", id->name);
731
732 /* Clear pointers to prevent tracing into released initdata. */
733 spin_lock_irqsave(&id->lock, flags);
734 id->areas = NULL;
735 id->active_pages = NULL;
736 id->active_entries = NULL;
737 spin_unlock_irqrestore(&id->lock, flags);
738
739 return;
740 }
741
742 /* Replace static trace area with dynamic copy. */
743 spin_lock_irqsave(&id->lock, flags);
744 debug_events_append(copy, id);
745 debug_areas_swap(id, copy);
746 spin_unlock_irqrestore(&id->lock, flags);
747
748 /* Clear pointers to initdata and discard copy. */
749 copy->areas = NULL;
750 copy->active_pages = NULL;
751 copy->active_entries = NULL;
752 debug_info_free(copy);
753
754 mutex_lock(&debug_mutex);
755 _debug_register(id);
756 mutex_unlock(&debug_mutex);
757}
758
759/* Remove debugfs entries and remove from internal list. */
760static void _debug_unregister(debug_info_t *id)
761{
762 int i;
763
764 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
765 if (!id->views[i])
766 continue;
767 debugfs_remove(id->debugfs_entries[i]);
768 }
769 debugfs_remove(id->debugfs_root_entry);
770 if (id == debug_area_first)
771 debug_area_first = id->next;
772 if (id == debug_area_last)
773 debug_area_last = id->prev;
774 if (id->prev)
775 id->prev->next = id->next;
776 if (id->next)
777 id->next->prev = id->prev;
778}
779
780/**
781 * debug_unregister() - give back debug area.
782 *
783 * @id: handle for debug log
784 *
785 * Return:
786 * none
787 */
788void debug_unregister(debug_info_t *id)
789{
790 if (!id)
791 return;
792 mutex_lock(&debug_mutex);
793 _debug_unregister(id);
794 mutex_unlock(&debug_mutex);
795
796 debug_info_put(id);
797}
798EXPORT_SYMBOL(debug_unregister);
799
800/*
801 * debug_set_size:
802 * - set area size (number of pages) and number of areas
803 */
804static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
805{
806 debug_info_t *new_id;
807 unsigned long flags;
808
809 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
810 return -EINVAL;
811
812 new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
813 id->level, ALL_AREAS);
814 if (!new_id) {
815 pr_info("Allocating memory for %i pages failed\n",
816 pages_per_area);
817 return -ENOMEM;
818 }
819
820 spin_lock_irqsave(&id->lock, flags);
821 debug_events_append(new_id, id);
822 debug_areas_swap(new_id, id);
823 debug_info_free(new_id);
824 spin_unlock_irqrestore(&id->lock, flags);
825 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
826
827 return 0;
828}
829
830/**
831 * debug_set_level() - Sets new actual debug level if new_level is valid.
832 *
833 * @id: handle for debug log
834 * @new_level: new debug level
835 *
836 * Return:
837 * none
838 */
839void debug_set_level(debug_info_t *id, int new_level)
840{
841 unsigned long flags;
842
843 if (!id)
844 return;
845
846 if (new_level == DEBUG_OFF_LEVEL) {
847 pr_info("%s: switched off\n", id->name);
848 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
849 pr_info("%s: level %i is out of range (%i - %i)\n",
850 id->name, new_level, 0, DEBUG_MAX_LEVEL);
851 return;
852 }
853
854 spin_lock_irqsave(&id->lock, flags);
855 id->level = new_level;
856 spin_unlock_irqrestore(&id->lock, flags);
857}
858EXPORT_SYMBOL(debug_set_level);
859
860/*
861 * proceed_active_entry:
862 * - set active entry to next in the ring buffer
863 */
864static inline void proceed_active_entry(debug_info_t *id)
865{
866 if ((id->active_entries[id->active_area] += id->entry_size)
867 > (PAGE_SIZE - id->entry_size)) {
868 id->active_entries[id->active_area] = 0;
869 id->active_pages[id->active_area] =
870 (id->active_pages[id->active_area] + 1) %
871 id->pages_per_area;
872 }
873}
874
875/*
876 * proceed_active_area:
877 * - set active area to next in the ring buffer
878 */
879static inline void proceed_active_area(debug_info_t *id)
880{
881 id->active_area++;
882 id->active_area = id->active_area % id->nr_areas;
883}
884
885/*
886 * get_active_entry:
887 */
888static inline debug_entry_t *get_active_entry(debug_info_t *id)
889{
890 return (debug_entry_t *) (((char *) id->areas[id->active_area]
891 [id->active_pages[id->active_area]]) +
892 id->active_entries[id->active_area]);
893}
894
895/* Swap debug areas of a and b. */
896static void debug_areas_swap(debug_info_t *a, debug_info_t *b)
897{
898 swap(a->nr_areas, b->nr_areas);
899 swap(a->pages_per_area, b->pages_per_area);
900 swap(a->areas, b->areas);
901 swap(a->active_area, b->active_area);
902 swap(a->active_pages, b->active_pages);
903 swap(a->active_entries, b->active_entries);
904}
905
906/* Append all debug events in active area from source to destination log. */
907static void debug_events_append(debug_info_t *dest, debug_info_t *src)
908{
909 debug_entry_t *from, *to, *last;
910
911 if (!src->areas || !dest->areas)
912 return;
913
914 /* Loop over all entries in src, starting with oldest. */
915 from = get_active_entry(src);
916 last = from;
917 do {
918 if (from->clock != 0LL) {
919 to = get_active_entry(dest);
920 memset(to, 0, dest->entry_size);
921 memcpy(to, from, min(src->entry_size,
922 dest->entry_size));
923 proceed_active_entry(dest);
924 }
925
926 proceed_active_entry(src);
927 from = get_active_entry(src);
928 } while (from != last);
929}
930
931/*
932 * debug_finish_entry:
933 * - set timestamp, caller address, cpu number etc.
934 */
935
936static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
937 int level, int exception)
938{
939 unsigned long timestamp;
940 union tod_clock clk;
941
942 store_tod_clock_ext(&clk);
943 timestamp = clk.us;
944 timestamp -= TOD_UNIX_EPOCH >> 12;
945 active->clock = timestamp;
946 active->cpu = smp_processor_id();
947 active->caller = __builtin_return_address(0);
948 active->exception = exception;
949 active->level = level;
950 proceed_active_entry(id);
951 if (exception)
952 proceed_active_area(id);
953}
954
955static int debug_stoppable = 1;
956static int debug_active = 1;
957
958#define CTL_S390DBF_STOPPABLE 5678
959#define CTL_S390DBF_ACTIVE 5679
960
961/*
962 * proc handler for the running debug_active sysctl
963 * always allow read, allow write only if debug_stoppable is set or
964 * if debug_active is already off
965 */
966static int s390dbf_procactive(const struct ctl_table *table, int write,
967 void *buffer, size_t *lenp, loff_t *ppos)
968{
969 if (!write || debug_stoppable || !debug_active)
970 return proc_dointvec(table, write, buffer, lenp, ppos);
971 else
972 return 0;
973}
974
975static struct ctl_table s390dbf_table[] = {
976 {
977 .procname = "debug_stoppable",
978 .data = &debug_stoppable,
979 .maxlen = sizeof(int),
980 .mode = S_IRUGO | S_IWUSR,
981 .proc_handler = proc_dointvec,
982 },
983 {
984 .procname = "debug_active",
985 .data = &debug_active,
986 .maxlen = sizeof(int),
987 .mode = S_IRUGO | S_IWUSR,
988 .proc_handler = s390dbf_procactive,
989 },
990};
991
992static struct ctl_table_header *s390dbf_sysctl_header;
993
994/**
995 * debug_stop_all() - stops the debug feature if stopping is allowed.
996 *
997 * Return:
998 * - none
999 *
1000 * Currently used in case of a kernel oops.
1001 */
1002void debug_stop_all(void)
1003{
1004 if (debug_stoppable)
1005 debug_active = 0;
1006}
1007EXPORT_SYMBOL(debug_stop_all);
1008
1009/**
1010 * debug_set_critical() - event/exception functions try lock instead of spin.
1011 *
1012 * Return:
1013 * - none
1014 *
1015 * Currently used in case of stopping all CPUs but the current one.
1016 * Once in this state, functions to write a debug entry for an
1017 * event or exception no longer spin on the debug area lock,
1018 * but only try to get it and fail if they do not get the lock.
1019 */
1020void debug_set_critical(void)
1021{
1022 debug_critical = 1;
1023}
1024
1025/*
1026 * debug_event_common:
1027 * - write debug entry with given size
1028 */
1029debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
1030 int len)
1031{
1032 debug_entry_t *active;
1033 unsigned long flags;
1034
1035 if (!debug_active || !id->areas)
1036 return NULL;
1037 if (debug_critical) {
1038 if (!spin_trylock_irqsave(&id->lock, flags))
1039 return NULL;
1040 } else {
1041 spin_lock_irqsave(&id->lock, flags);
1042 }
1043 do {
1044 active = get_active_entry(id);
1045 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1046 if (len < id->buf_size)
1047 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1048 debug_finish_entry(id, active, level, 0);
1049 len -= id->buf_size;
1050 buf += id->buf_size;
1051 } while (len > 0);
1052
1053 spin_unlock_irqrestore(&id->lock, flags);
1054 return active;
1055}
1056EXPORT_SYMBOL(debug_event_common);
1057
1058/*
1059 * debug_exception_common:
1060 * - write debug entry with given size and switch to next debug area
1061 */
1062debug_entry_t *debug_exception_common(debug_info_t *id, int level,
1063 const void *buf, int len)
1064{
1065 debug_entry_t *active;
1066 unsigned long flags;
1067
1068 if (!debug_active || !id->areas)
1069 return NULL;
1070 if (debug_critical) {
1071 if (!spin_trylock_irqsave(&id->lock, flags))
1072 return NULL;
1073 } else {
1074 spin_lock_irqsave(&id->lock, flags);
1075 }
1076 do {
1077 active = get_active_entry(id);
1078 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1079 if (len < id->buf_size)
1080 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1081 debug_finish_entry(id, active, level, len <= id->buf_size);
1082 len -= id->buf_size;
1083 buf += id->buf_size;
1084 } while (len > 0);
1085
1086 spin_unlock_irqrestore(&id->lock, flags);
1087 return active;
1088}
1089EXPORT_SYMBOL(debug_exception_common);
1090
1091/*
1092 * counts arguments in format string for sprintf view
1093 */
1094static inline int debug_count_numargs(char *string)
1095{
1096 int numargs = 0;
1097
1098 while (*string) {
1099 if (*string++ == '%')
1100 numargs++;
1101 }
1102 return numargs;
1103}
1104
1105/*
1106 * debug_sprintf_event:
1107 */
1108debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1109{
1110 debug_sprintf_entry_t *curr_event;
1111 debug_entry_t *active;
1112 unsigned long flags;
1113 int numargs, idx;
1114 va_list ap;
1115
1116 if (!debug_active || !id->areas)
1117 return NULL;
1118 numargs = debug_count_numargs(string);
1119
1120 if (debug_critical) {
1121 if (!spin_trylock_irqsave(&id->lock, flags))
1122 return NULL;
1123 } else {
1124 spin_lock_irqsave(&id->lock, flags);
1125 }
1126 active = get_active_entry(id);
1127 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1128 va_start(ap, string);
1129 curr_event->string = string;
1130 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1131 curr_event->args[idx] = va_arg(ap, long);
1132 va_end(ap);
1133 debug_finish_entry(id, active, level, 0);
1134 spin_unlock_irqrestore(&id->lock, flags);
1135
1136 return active;
1137}
1138EXPORT_SYMBOL(__debug_sprintf_event);
1139
1140/*
1141 * debug_sprintf_exception:
1142 */
1143debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1144{
1145 debug_sprintf_entry_t *curr_event;
1146 debug_entry_t *active;
1147 unsigned long flags;
1148 int numargs, idx;
1149 va_list ap;
1150
1151 if (!debug_active || !id->areas)
1152 return NULL;
1153
1154 numargs = debug_count_numargs(string);
1155
1156 if (debug_critical) {
1157 if (!spin_trylock_irqsave(&id->lock, flags))
1158 return NULL;
1159 } else {
1160 spin_lock_irqsave(&id->lock, flags);
1161 }
1162 active = get_active_entry(id);
1163 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1164 va_start(ap, string);
1165 curr_event->string = string;
1166 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1167 curr_event->args[idx] = va_arg(ap, long);
1168 va_end(ap);
1169 debug_finish_entry(id, active, level, 1);
1170 spin_unlock_irqrestore(&id->lock, flags);
1171
1172 return active;
1173}
1174EXPORT_SYMBOL(__debug_sprintf_exception);
1175
1176/**
1177 * debug_register_view() - registers new debug view and creates debugfs
1178 * dir entry
1179 *
1180 * @id: handle for debug log
1181 * @view: pointer to debug view struct
1182 *
1183 * Return:
1184 * - 0 : ok
1185 * - < 0: Error
1186 */
1187int debug_register_view(debug_info_t *id, struct debug_view *view)
1188{
1189 unsigned long flags;
1190 struct dentry *pde;
1191 umode_t mode;
1192 int rc = 0;
1193 int i;
1194
1195 if (!id)
1196 goto out;
1197 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1198 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1199 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1200 if (!view->input_proc)
1201 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1202 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1203 id, &debug_file_ops);
1204 spin_lock_irqsave(&id->lock, flags);
1205 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1206 if (!id->views[i])
1207 break;
1208 }
1209 if (i == DEBUG_MAX_VIEWS) {
1210 rc = -1;
1211 } else {
1212 id->views[i] = view;
1213 id->debugfs_entries[i] = pde;
1214 }
1215 spin_unlock_irqrestore(&id->lock, flags);
1216 if (rc) {
1217 pr_err("Registering view %s/%s would exceed the maximum "
1218 "number of views %i\n", id->name, view->name, i);
1219 debugfs_remove(pde);
1220 }
1221out:
1222 return rc;
1223}
1224EXPORT_SYMBOL(debug_register_view);
1225
1226/**
1227 * debug_unregister_view() - unregisters debug view and removes debugfs
1228 * dir entry
1229 *
1230 * @id: handle for debug log
1231 * @view: pointer to debug view struct
1232 *
1233 * Return:
1234 * - 0 : ok
1235 * - < 0: Error
1236 */
1237int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1238{
1239 struct dentry *dentry = NULL;
1240 unsigned long flags;
1241 int i, rc = 0;
1242
1243 if (!id)
1244 goto out;
1245 spin_lock_irqsave(&id->lock, flags);
1246 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1247 if (id->views[i] == view)
1248 break;
1249 }
1250 if (i == DEBUG_MAX_VIEWS) {
1251 rc = -1;
1252 } else {
1253 dentry = id->debugfs_entries[i];
1254 id->views[i] = NULL;
1255 id->debugfs_entries[i] = NULL;
1256 }
1257 spin_unlock_irqrestore(&id->lock, flags);
1258 debugfs_remove(dentry);
1259out:
1260 return rc;
1261}
1262EXPORT_SYMBOL(debug_unregister_view);
1263
1264static inline char *debug_get_user_string(const char __user *user_buf,
1265 size_t user_len)
1266{
1267 char *buffer;
1268
1269 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1270 if (!buffer)
1271 return ERR_PTR(-ENOMEM);
1272 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1273 kfree(buffer);
1274 return ERR_PTR(-EFAULT);
1275 }
1276 /* got the string, now strip linefeed. */
1277 if (buffer[user_len - 1] == '\n')
1278 buffer[user_len - 1] = 0;
1279 else
1280 buffer[user_len] = 0;
1281 return buffer;
1282}
1283
1284static inline int debug_get_uint(char *buf)
1285{
1286 int rc;
1287
1288 buf = skip_spaces(buf);
1289 rc = simple_strtoul(buf, &buf, 10);
1290 if (*buf)
1291 rc = -EINVAL;
1292 return rc;
1293}
1294
1295/*
1296 * functions for debug-views
1297 ***********************************
1298*/
1299
1300/*
1301 * prints out actual debug level
1302 */
1303
1304static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1305 char *out_buf, size_t out_buf_size)
1306{
1307 return scnprintf(out_buf, out_buf_size, "%i\n", id->pages_per_area);
1308}
1309
1310/*
1311 * reads new size (number of pages per debug area)
1312 */
1313
1314static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1315 struct file *file, const char __user *user_buf,
1316 size_t user_len, loff_t *offset)
1317{
1318 int rc, new_pages;
1319 char *str;
1320
1321 if (user_len > 0x10000)
1322 user_len = 0x10000;
1323 if (*offset != 0) {
1324 rc = -EPIPE;
1325 goto out;
1326 }
1327 str = debug_get_user_string(user_buf, user_len);
1328 if (IS_ERR(str)) {
1329 rc = PTR_ERR(str);
1330 goto out;
1331 }
1332 new_pages = debug_get_uint(str);
1333 if (new_pages < 0) {
1334 rc = -EINVAL;
1335 goto free_str;
1336 }
1337 rc = debug_set_size(id, id->nr_areas, new_pages);
1338 if (rc != 0) {
1339 rc = -EINVAL;
1340 goto free_str;
1341 }
1342 rc = user_len;
1343free_str:
1344 kfree(str);
1345out:
1346 *offset += user_len;
1347 return rc; /* number of input characters */
1348}
1349
1350/*
1351 * prints out actual debug level
1352 */
1353static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1354 char *out_buf, size_t out_buf_size)
1355{
1356 int rc = 0;
1357
1358 if (id->level == DEBUG_OFF_LEVEL)
1359 rc = scnprintf(out_buf, out_buf_size, "-\n");
1360 else
1361 rc = scnprintf(out_buf, out_buf_size, "%i\n", id->level);
1362 return rc;
1363}
1364
1365/*
1366 * reads new debug level
1367 */
1368static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1369 struct file *file, const char __user *user_buf,
1370 size_t user_len, loff_t *offset)
1371{
1372 int rc, new_level;
1373 char *str;
1374
1375 if (user_len > 0x10000)
1376 user_len = 0x10000;
1377 if (*offset != 0) {
1378 rc = -EPIPE;
1379 goto out;
1380 }
1381 str = debug_get_user_string(user_buf, user_len);
1382 if (IS_ERR(str)) {
1383 rc = PTR_ERR(str);
1384 goto out;
1385 }
1386 if (str[0] == '-') {
1387 debug_set_level(id, DEBUG_OFF_LEVEL);
1388 rc = user_len;
1389 goto free_str;
1390 } else {
1391 new_level = debug_get_uint(str);
1392 }
1393 if (new_level < 0) {
1394 pr_warn("%s is not a valid level for a debug feature\n", str);
1395 rc = -EINVAL;
1396 } else {
1397 debug_set_level(id, new_level);
1398 rc = user_len;
1399 }
1400free_str:
1401 kfree(str);
1402out:
1403 *offset += user_len;
1404 return rc; /* number of input characters */
1405}
1406
1407/*
1408 * flushes debug areas
1409 */
1410static void debug_flush(debug_info_t *id, int area)
1411{
1412 unsigned long flags;
1413 int i, j;
1414
1415 if (!id || !id->areas)
1416 return;
1417 spin_lock_irqsave(&id->lock, flags);
1418 if (area == DEBUG_FLUSH_ALL) {
1419 id->active_area = 0;
1420 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1421 for (i = 0; i < id->nr_areas; i++) {
1422 id->active_pages[i] = 0;
1423 for (j = 0; j < id->pages_per_area; j++)
1424 memset(id->areas[i][j], 0, PAGE_SIZE);
1425 }
1426 } else if (area >= 0 && area < id->nr_areas) {
1427 id->active_entries[area] = 0;
1428 id->active_pages[area] = 0;
1429 for (i = 0; i < id->pages_per_area; i++)
1430 memset(id->areas[area][i], 0, PAGE_SIZE);
1431 }
1432 spin_unlock_irqrestore(&id->lock, flags);
1433}
1434
1435/*
1436 * view function: flushes debug areas
1437 */
1438static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1439 struct file *file, const char __user *user_buf,
1440 size_t user_len, loff_t *offset)
1441{
1442 char input_buf[1];
1443 int rc = user_len;
1444
1445 if (user_len > 0x10000)
1446 user_len = 0x10000;
1447 if (*offset != 0) {
1448 rc = -EPIPE;
1449 goto out;
1450 }
1451 if (copy_from_user(input_buf, user_buf, 1)) {
1452 rc = -EFAULT;
1453 goto out;
1454 }
1455 if (input_buf[0] == '-') {
1456 debug_flush(id, DEBUG_FLUSH_ALL);
1457 goto out;
1458 }
1459 if (isdigit(input_buf[0])) {
1460 int area = ((int) input_buf[0] - (int) '0');
1461
1462 debug_flush(id, area);
1463 goto out;
1464 }
1465
1466 pr_info("Flushing debug data failed because %c is not a valid "
1467 "area\n", input_buf[0]);
1468
1469out:
1470 *offset += user_len;
1471 return rc; /* number of input characters */
1472}
1473
1474/*
1475 * prints debug data in hex/ascii format
1476 */
1477static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1478 char *out_buf, size_t out_buf_size, const char *in_buf)
1479{
1480 int i, rc = 0;
1481
1482 for (i = 0; i < id->buf_size; i++) {
1483 rc += scnprintf(out_buf + rc, out_buf_size - rc,
1484 "%02x ", ((unsigned char *)in_buf)[i]);
1485 }
1486 rc += scnprintf(out_buf + rc, out_buf_size - rc, "| ");
1487 for (i = 0; i < id->buf_size; i++) {
1488 unsigned char c = in_buf[i];
1489
1490 if (isascii(c) && isprint(c))
1491 rc += scnprintf(out_buf + rc, out_buf_size - rc, "%c", c);
1492 else
1493 rc += scnprintf(out_buf + rc, out_buf_size - rc, ".");
1494 }
1495 rc += scnprintf(out_buf + rc, out_buf_size - rc, "\n");
1496 return rc;
1497}
1498
1499/*
1500 * prints header for debug entry
1501 */
1502int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1503 int area, debug_entry_t *entry, char *out_buf,
1504 size_t out_buf_size)
1505{
1506 unsigned long sec, usec;
1507 unsigned long caller;
1508 unsigned int level;
1509 char *except_str;
1510 int rc = 0;
1511
1512 level = entry->level;
1513 sec = entry->clock;
1514 usec = do_div(sec, USEC_PER_SEC);
1515
1516 if (entry->exception)
1517 except_str = "*";
1518 else
1519 except_str = "-";
1520 caller = (unsigned long) entry->caller;
1521 rc += scnprintf(out_buf, out_buf_size, "%02i %011ld:%06lu %1u %1s %04u %px ",
1522 area, sec, usec, level, except_str,
1523 entry->cpu, (void *)caller);
1524 return rc;
1525}
1526EXPORT_SYMBOL(debug_dflt_header_fn);
1527
1528/*
1529 * prints debug data sprintf-formatted:
1530 * debug_sprinf_event/exception calls must be used together with this view
1531 */
1532
1533#define DEBUG_SPRINTF_MAX_ARGS 10
1534
1535static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1536 char *out_buf, size_t out_buf_size, const char *inbuf)
1537{
1538 debug_sprintf_entry_t *curr_event = (debug_sprintf_entry_t *)inbuf;
1539 int num_longs, num_used_args = 0, i, rc = 0;
1540 int index[DEBUG_SPRINTF_MAX_ARGS];
1541
1542 /* count of longs fit into one entry */
1543 num_longs = id->buf_size / sizeof(long);
1544
1545 if (num_longs < 1)
1546 goto out; /* bufsize of entry too small */
1547 if (num_longs == 1) {
1548 /* no args, we use only the string */
1549 rc = strscpy(out_buf, curr_event->string, out_buf_size);
1550 if (rc == -E2BIG)
1551 rc = out_buf_size;
1552 goto out;
1553 }
1554
1555 /* number of arguments used for sprintf (without the format string) */
1556 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1557
1558 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1559
1560 for (i = 0; i < num_used_args; i++)
1561 index[i] = i;
1562
1563 rc = scnprintf(out_buf, out_buf_size,
1564 curr_event->string, curr_event->args[index[0]],
1565 curr_event->args[index[1]], curr_event->args[index[2]],
1566 curr_event->args[index[3]], curr_event->args[index[4]],
1567 curr_event->args[index[5]], curr_event->args[index[6]],
1568 curr_event->args[index[7]], curr_event->args[index[8]],
1569 curr_event->args[index[9]]);
1570out:
1571 return rc;
1572}
1573
1574/*
1575 * debug_init:
1576 * - is called exactly once to initialize the debug feature
1577 */
1578static int __init debug_init(void)
1579{
1580 s390dbf_sysctl_header = register_sysctl("s390dbf", s390dbf_table);
1581 mutex_lock(&debug_mutex);
1582 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1583 initialized = 1;
1584 mutex_unlock(&debug_mutex);
1585 return 0;
1586}
1587postcore_initcall(debug_init);
1/*
2 * S/390 debug facility
3 *
4 * Copyright IBM Corp. 1999, 2012
5 *
6 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
7 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
8 *
9 * Bugreports to: <Linux390@de.ibm.com>
10 */
11
12#define KMSG_COMPONENT "s390dbf"
13#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14
15#include <linux/stddef.h>
16#include <linux/kernel.h>
17#include <linux/errno.h>
18#include <linux/slab.h>
19#include <linux/ctype.h>
20#include <linux/string.h>
21#include <linux/sysctl.h>
22#include <asm/uaccess.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/fs.h>
26#include <linux/debugfs.h>
27
28#include <asm/debug.h>
29
30#define DEBUG_PROLOG_ENTRY -1
31
32#define ALL_AREAS 0 /* copy all debug areas */
33#define NO_AREAS 1 /* copy no debug areas */
34
35/* typedefs */
36
37typedef struct file_private_info {
38 loff_t offset; /* offset of last read in file */
39 int act_area; /* number of last formated area */
40 int act_page; /* act page in given area */
41 int act_entry; /* last formated entry (offset */
42 /* relative to beginning of last */
43 /* formated page) */
44 size_t act_entry_offset; /* up to this offset we copied */
45 /* in last read the last formated */
46 /* entry to userland */
47 char temp_buf[2048]; /* buffer for output */
48 debug_info_t *debug_info_org; /* original debug information */
49 debug_info_t *debug_info_snap; /* snapshot of debug information */
50 struct debug_view *view; /* used view of debug info */
51} file_private_info_t;
52
53typedef struct
54{
55 char *string;
56 /*
57 * This assumes that all args are converted into longs
58 * on L/390 this is the case for all types of parameter
59 * except of floats, and long long (32 bit)
60 *
61 */
62 long args[0];
63} debug_sprintf_entry_t;
64
65
66/* internal function prototyes */
67
68static int debug_init(void);
69static ssize_t debug_output(struct file *file, char __user *user_buf,
70 size_t user_len, loff_t * offset);
71static ssize_t debug_input(struct file *file, const char __user *user_buf,
72 size_t user_len, loff_t * offset);
73static int debug_open(struct inode *inode, struct file *file);
74static int debug_close(struct inode *inode, struct file *file);
75static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76 int nr_areas, int buf_size, umode_t mode);
77static void debug_info_get(debug_info_t *);
78static void debug_info_put(debug_info_t *);
79static int debug_prolog_level_fn(debug_info_t * id,
80 struct debug_view *view, char *out_buf);
81static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
82 struct file *file, const char __user *user_buf,
83 size_t user_buf_size, loff_t * offset);
84static int debug_prolog_pages_fn(debug_info_t * id,
85 struct debug_view *view, char *out_buf);
86static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
87 struct file *file, const char __user *user_buf,
88 size_t user_buf_size, loff_t * offset);
89static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
90 struct file *file, const char __user *user_buf,
91 size_t user_buf_size, loff_t * offset);
92static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93 char *out_buf, const char *in_buf);
94static int debug_raw_format_fn(debug_info_t * id,
95 struct debug_view *view, char *out_buf,
96 const char *in_buf);
97static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98 int area, debug_entry_t * entry, char *out_buf);
99
100static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
101 char *out_buf, debug_sprintf_entry_t *curr_event);
102
103/* globals */
104
105struct debug_view debug_raw_view = {
106 "raw",
107 NULL,
108 &debug_raw_header_fn,
109 &debug_raw_format_fn,
110 NULL,
111 NULL
112};
113EXPORT_SYMBOL(debug_raw_view);
114
115struct debug_view debug_hex_ascii_view = {
116 "hex_ascii",
117 NULL,
118 &debug_dflt_header_fn,
119 &debug_hex_ascii_format_fn,
120 NULL,
121 NULL
122};
123EXPORT_SYMBOL(debug_hex_ascii_view);
124
125static struct debug_view debug_level_view = {
126 "level",
127 &debug_prolog_level_fn,
128 NULL,
129 NULL,
130 &debug_input_level_fn,
131 NULL
132};
133
134static struct debug_view debug_pages_view = {
135 "pages",
136 &debug_prolog_pages_fn,
137 NULL,
138 NULL,
139 &debug_input_pages_fn,
140 NULL
141};
142
143static struct debug_view debug_flush_view = {
144 "flush",
145 NULL,
146 NULL,
147 NULL,
148 &debug_input_flush_fn,
149 NULL
150};
151
152struct debug_view debug_sprintf_view = {
153 "sprintf",
154 NULL,
155 &debug_dflt_header_fn,
156 (debug_format_proc_t*)&debug_sprintf_format_fn,
157 NULL,
158 NULL
159};
160EXPORT_SYMBOL(debug_sprintf_view);
161
162/* used by dump analysis tools to determine version of debug feature */
163static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
164
165/* static globals */
166
167static debug_info_t *debug_area_first = NULL;
168static debug_info_t *debug_area_last = NULL;
169static DEFINE_MUTEX(debug_mutex);
170
171static int initialized;
172static int debug_critical;
173
174static const struct file_operations debug_file_ops = {
175 .owner = THIS_MODULE,
176 .read = debug_output,
177 .write = debug_input,
178 .open = debug_open,
179 .release = debug_close,
180 .llseek = no_llseek,
181};
182
183static struct dentry *debug_debugfs_root_entry;
184
185/* functions */
186
187/*
188 * debug_areas_alloc
189 * - Debug areas are implemented as a threedimensonal array:
190 * areas[areanumber][pagenumber][pageoffset]
191 */
192
193static debug_entry_t***
194debug_areas_alloc(int pages_per_area, int nr_areas)
195{
196 debug_entry_t*** areas;
197 int i,j;
198
199 areas = kmalloc(nr_areas *
200 sizeof(debug_entry_t**),
201 GFP_KERNEL);
202 if (!areas)
203 goto fail_malloc_areas;
204 for (i = 0; i < nr_areas; i++) {
205 areas[i] = kmalloc(pages_per_area *
206 sizeof(debug_entry_t*),GFP_KERNEL);
207 if (!areas[i]) {
208 goto fail_malloc_areas2;
209 }
210 for(j = 0; j < pages_per_area; j++) {
211 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
212 if(!areas[i][j]) {
213 for(j--; j >=0 ; j--) {
214 kfree(areas[i][j]);
215 }
216 kfree(areas[i]);
217 goto fail_malloc_areas2;
218 }
219 }
220 }
221 return areas;
222
223fail_malloc_areas2:
224 for(i--; i >= 0; i--){
225 for(j=0; j < pages_per_area;j++){
226 kfree(areas[i][j]);
227 }
228 kfree(areas[i]);
229 }
230 kfree(areas);
231fail_malloc_areas:
232 return NULL;
233
234}
235
236
237/*
238 * debug_info_alloc
239 * - alloc new debug-info
240 */
241
242static debug_info_t*
243debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
244 int buf_size, int level, int mode)
245{
246 debug_info_t* rc;
247
248 /* alloc everything */
249
250 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
251 if(!rc)
252 goto fail_malloc_rc;
253 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254 if(!rc->active_entries)
255 goto fail_malloc_active_entries;
256 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
257 if(!rc->active_pages)
258 goto fail_malloc_active_pages;
259 if((mode == ALL_AREAS) && (pages_per_area != 0)){
260 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
261 if(!rc->areas)
262 goto fail_malloc_areas;
263 } else {
264 rc->areas = NULL;
265 }
266
267 /* initialize members */
268
269 spin_lock_init(&rc->lock);
270 rc->pages_per_area = pages_per_area;
271 rc->nr_areas = nr_areas;
272 rc->active_area = 0;
273 rc->level = level;
274 rc->buf_size = buf_size;
275 rc->entry_size = sizeof(debug_entry_t) + buf_size;
276 strlcpy(rc->name, name, sizeof(rc->name));
277 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
278 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
279 sizeof(struct dentry*));
280 atomic_set(&(rc->ref_count), 0);
281
282 return rc;
283
284fail_malloc_areas:
285 kfree(rc->active_pages);
286fail_malloc_active_pages:
287 kfree(rc->active_entries);
288fail_malloc_active_entries:
289 kfree(rc);
290fail_malloc_rc:
291 return NULL;
292}
293
294/*
295 * debug_areas_free
296 * - free all debug areas
297 */
298
299static void
300debug_areas_free(debug_info_t* db_info)
301{
302 int i,j;
303
304 if(!db_info->areas)
305 return;
306 for (i = 0; i < db_info->nr_areas; i++) {
307 for(j = 0; j < db_info->pages_per_area; j++) {
308 kfree(db_info->areas[i][j]);
309 }
310 kfree(db_info->areas[i]);
311 }
312 kfree(db_info->areas);
313 db_info->areas = NULL;
314}
315
316/*
317 * debug_info_free
318 * - free memory debug-info
319 */
320
321static void
322debug_info_free(debug_info_t* db_info){
323 debug_areas_free(db_info);
324 kfree(db_info->active_entries);
325 kfree(db_info->active_pages);
326 kfree(db_info);
327}
328
329/*
330 * debug_info_create
331 * - create new debug-info
332 */
333
334static debug_info_t*
335debug_info_create(const char *name, int pages_per_area, int nr_areas,
336 int buf_size, umode_t mode)
337{
338 debug_info_t* rc;
339
340 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
341 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
342 if(!rc)
343 goto out;
344
345 rc->mode = mode & ~S_IFMT;
346
347 /* create root directory */
348 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
349 debug_debugfs_root_entry);
350
351 /* append new element to linked list */
352 if (!debug_area_first) {
353 /* first element in list */
354 debug_area_first = rc;
355 rc->prev = NULL;
356 } else {
357 /* append element to end of list */
358 debug_area_last->next = rc;
359 rc->prev = debug_area_last;
360 }
361 debug_area_last = rc;
362 rc->next = NULL;
363
364 debug_info_get(rc);
365out:
366 return rc;
367}
368
369/*
370 * debug_info_copy
371 * - copy debug-info
372 */
373
374static debug_info_t*
375debug_info_copy(debug_info_t* in, int mode)
376{
377 int i,j;
378 debug_info_t* rc;
379 unsigned long flags;
380
381 /* get a consistent copy of the debug areas */
382 do {
383 rc = debug_info_alloc(in->name, in->pages_per_area,
384 in->nr_areas, in->buf_size, in->level, mode);
385 spin_lock_irqsave(&in->lock, flags);
386 if(!rc)
387 goto out;
388 /* has something changed in the meantime ? */
389 if((rc->pages_per_area == in->pages_per_area) &&
390 (rc->nr_areas == in->nr_areas)) {
391 break;
392 }
393 spin_unlock_irqrestore(&in->lock, flags);
394 debug_info_free(rc);
395 } while (1);
396
397 if (mode == NO_AREAS)
398 goto out;
399
400 for(i = 0; i < in->nr_areas; i++){
401 for(j = 0; j < in->pages_per_area; j++) {
402 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
403 }
404 }
405out:
406 spin_unlock_irqrestore(&in->lock, flags);
407 return rc;
408}
409
410/*
411 * debug_info_get
412 * - increments reference count for debug-info
413 */
414
415static void
416debug_info_get(debug_info_t * db_info)
417{
418 if (db_info)
419 atomic_inc(&db_info->ref_count);
420}
421
422/*
423 * debug_info_put:
424 * - decreases reference count for debug-info and frees it if necessary
425 */
426
427static void
428debug_info_put(debug_info_t *db_info)
429{
430 int i;
431
432 if (!db_info)
433 return;
434 if (atomic_dec_and_test(&db_info->ref_count)) {
435 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
436 if (!db_info->views[i])
437 continue;
438 debugfs_remove(db_info->debugfs_entries[i]);
439 }
440 debugfs_remove(db_info->debugfs_root_entry);
441 if(db_info == debug_area_first)
442 debug_area_first = db_info->next;
443 if(db_info == debug_area_last)
444 debug_area_last = db_info->prev;
445 if(db_info->prev) db_info->prev->next = db_info->next;
446 if(db_info->next) db_info->next->prev = db_info->prev;
447 debug_info_free(db_info);
448 }
449}
450
451/*
452 * debug_format_entry:
453 * - format one debug entry and return size of formated data
454 */
455
456static int
457debug_format_entry(file_private_info_t *p_info)
458{
459 debug_info_t *id_snap = p_info->debug_info_snap;
460 struct debug_view *view = p_info->view;
461 debug_entry_t *act_entry;
462 size_t len = 0;
463 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
464 /* print prolog */
465 if (view->prolog_proc)
466 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
467 goto out;
468 }
469 if (!id_snap->areas) /* this is true, if we have a prolog only view */
470 goto out; /* or if 'pages_per_area' is 0 */
471 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
472 [p_info->act_page] + p_info->act_entry);
473
474 if (act_entry->id.stck == 0LL)
475 goto out; /* empty entry */
476 if (view->header_proc)
477 len += view->header_proc(id_snap, view, p_info->act_area,
478 act_entry, p_info->temp_buf + len);
479 if (view->format_proc)
480 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
481 DEBUG_DATA(act_entry));
482out:
483 return len;
484}
485
486/*
487 * debug_next_entry:
488 * - goto next entry in p_info
489 */
490
491static inline int
492debug_next_entry(file_private_info_t *p_info)
493{
494 debug_info_t *id;
495
496 id = p_info->debug_info_snap;
497 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
498 p_info->act_entry = 0;
499 p_info->act_page = 0;
500 goto out;
501 }
502 if(!id->areas)
503 return 1;
504 p_info->act_entry += id->entry_size;
505 /* switch to next page, if we reached the end of the page */
506 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
507 /* next page */
508 p_info->act_entry = 0;
509 p_info->act_page += 1;
510 if((p_info->act_page % id->pages_per_area) == 0) {
511 /* next area */
512 p_info->act_area++;
513 p_info->act_page=0;
514 }
515 if(p_info->act_area >= id->nr_areas)
516 return 1;
517 }
518out:
519 return 0;
520}
521
522/*
523 * debug_output:
524 * - called for user read()
525 * - copies formated debug entries to the user buffer
526 */
527
528static ssize_t
529debug_output(struct file *file, /* file descriptor */
530 char __user *user_buf, /* user buffer */
531 size_t len, /* length of buffer */
532 loff_t *offset) /* offset in the file */
533{
534 size_t count = 0;
535 size_t entry_offset;
536 file_private_info_t *p_info;
537
538 p_info = ((file_private_info_t *) file->private_data);
539 if (*offset != p_info->offset)
540 return -EPIPE;
541 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
542 return 0;
543 entry_offset = p_info->act_entry_offset;
544 while(count < len){
545 int formatted_line_size;
546 int formatted_line_residue;
547 int user_buf_residue;
548 size_t copy_size;
549
550 formatted_line_size = debug_format_entry(p_info);
551 formatted_line_residue = formatted_line_size - entry_offset;
552 user_buf_residue = len-count;
553 copy_size = min(user_buf_residue, formatted_line_residue);
554 if(copy_size){
555 if (copy_to_user(user_buf + count, p_info->temp_buf
556 + entry_offset, copy_size))
557 return -EFAULT;
558 count += copy_size;
559 entry_offset += copy_size;
560 }
561 if(copy_size == formatted_line_residue){
562 entry_offset = 0;
563 if(debug_next_entry(p_info))
564 goto out;
565 }
566 }
567out:
568 p_info->offset = *offset + count;
569 p_info->act_entry_offset = entry_offset;
570 *offset = p_info->offset;
571 return count;
572}
573
574/*
575 * debug_input:
576 * - called for user write()
577 * - calls input function of view
578 */
579
580static ssize_t
581debug_input(struct file *file, const char __user *user_buf, size_t length,
582 loff_t *offset)
583{
584 int rc = 0;
585 file_private_info_t *p_info;
586
587 mutex_lock(&debug_mutex);
588 p_info = ((file_private_info_t *) file->private_data);
589 if (p_info->view->input_proc)
590 rc = p_info->view->input_proc(p_info->debug_info_org,
591 p_info->view, file, user_buf,
592 length, offset);
593 else
594 rc = -EPERM;
595 mutex_unlock(&debug_mutex);
596 return rc; /* number of input characters */
597}
598
599/*
600 * debug_open:
601 * - called for user open()
602 * - copies formated output to private_data area of the file
603 * handle
604 */
605
606static int
607debug_open(struct inode *inode, struct file *file)
608{
609 int i, rc = 0;
610 file_private_info_t *p_info;
611 debug_info_t *debug_info, *debug_info_snapshot;
612
613 mutex_lock(&debug_mutex);
614 debug_info = file_inode(file)->i_private;
615 /* find debug view */
616 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
617 if (!debug_info->views[i])
618 continue;
619 else if (debug_info->debugfs_entries[i] ==
620 file->f_path.dentry) {
621 goto found; /* found view ! */
622 }
623 }
624 /* no entry found */
625 rc = -EINVAL;
626 goto out;
627
628found:
629
630 /* Make snapshot of current debug areas to get it consistent. */
631 /* To copy all the areas is only needed, if we have a view which */
632 /* formats the debug areas. */
633
634 if(!debug_info->views[i]->format_proc &&
635 !debug_info->views[i]->header_proc){
636 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
637 } else {
638 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
639 }
640
641 if(!debug_info_snapshot){
642 rc = -ENOMEM;
643 goto out;
644 }
645 p_info = kmalloc(sizeof(file_private_info_t),
646 GFP_KERNEL);
647 if(!p_info){
648 debug_info_free(debug_info_snapshot);
649 rc = -ENOMEM;
650 goto out;
651 }
652 p_info->offset = 0;
653 p_info->debug_info_snap = debug_info_snapshot;
654 p_info->debug_info_org = debug_info;
655 p_info->view = debug_info->views[i];
656 p_info->act_area = 0;
657 p_info->act_page = 0;
658 p_info->act_entry = DEBUG_PROLOG_ENTRY;
659 p_info->act_entry_offset = 0;
660 file->private_data = p_info;
661 debug_info_get(debug_info);
662 nonseekable_open(inode, file);
663out:
664 mutex_unlock(&debug_mutex);
665 return rc;
666}
667
668/*
669 * debug_close:
670 * - called for user close()
671 * - deletes private_data area of the file handle
672 */
673
674static int
675debug_close(struct inode *inode, struct file *file)
676{
677 file_private_info_t *p_info;
678 p_info = (file_private_info_t *) file->private_data;
679 if(p_info->debug_info_snap)
680 debug_info_free(p_info->debug_info_snap);
681 debug_info_put(p_info->debug_info_org);
682 kfree(file->private_data);
683 return 0; /* success */
684}
685
686/*
687 * debug_register_mode:
688 * - Creates and initializes debug area for the caller
689 * The mode parameter allows to specify access rights for the s390dbf files
690 * - Returns handle for debug area
691 */
692
693debug_info_t *debug_register_mode(const char *name, int pages_per_area,
694 int nr_areas, int buf_size, umode_t mode,
695 uid_t uid, gid_t gid)
696{
697 debug_info_t *rc = NULL;
698
699 /* Since debugfs currently does not support uid/gid other than root, */
700 /* we do not allow gid/uid != 0 until we get support for that. */
701 if ((uid != 0) || (gid != 0))
702 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
703 BUG_ON(!initialized);
704 mutex_lock(&debug_mutex);
705
706 /* create new debug_info */
707
708 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
709 if(!rc)
710 goto out;
711 debug_register_view(rc, &debug_level_view);
712 debug_register_view(rc, &debug_flush_view);
713 debug_register_view(rc, &debug_pages_view);
714out:
715 if (!rc){
716 pr_err("Registering debug feature %s failed\n", name);
717 }
718 mutex_unlock(&debug_mutex);
719 return rc;
720}
721EXPORT_SYMBOL(debug_register_mode);
722
723/*
724 * debug_register:
725 * - creates and initializes debug area for the caller
726 * - returns handle for debug area
727 */
728
729debug_info_t *debug_register(const char *name, int pages_per_area,
730 int nr_areas, int buf_size)
731{
732 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
733 S_IRUSR | S_IWUSR, 0, 0);
734}
735EXPORT_SYMBOL(debug_register);
736
737/*
738 * debug_unregister:
739 * - give back debug area
740 */
741
742void
743debug_unregister(debug_info_t * id)
744{
745 if (!id)
746 goto out;
747 mutex_lock(&debug_mutex);
748 debug_info_put(id);
749 mutex_unlock(&debug_mutex);
750
751out:
752 return;
753}
754EXPORT_SYMBOL(debug_unregister);
755
756/*
757 * debug_set_size:
758 * - set area size (number of pages) and number of areas
759 */
760static int
761debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
762{
763 unsigned long flags;
764 debug_entry_t *** new_areas;
765 int rc=0;
766
767 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
768 return -EINVAL;
769 if(pages_per_area > 0){
770 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
771 if(!new_areas) {
772 pr_info("Allocating memory for %i pages failed\n",
773 pages_per_area);
774 rc = -ENOMEM;
775 goto out;
776 }
777 } else {
778 new_areas = NULL;
779 }
780 spin_lock_irqsave(&id->lock,flags);
781 debug_areas_free(id);
782 id->areas = new_areas;
783 id->nr_areas = nr_areas;
784 id->pages_per_area = pages_per_area;
785 id->active_area = 0;
786 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
787 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
788 spin_unlock_irqrestore(&id->lock,flags);
789 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
790out:
791 return rc;
792}
793
794/*
795 * debug_set_level:
796 * - set actual debug level
797 */
798
799void
800debug_set_level(debug_info_t* id, int new_level)
801{
802 unsigned long flags;
803 if(!id)
804 return;
805 spin_lock_irqsave(&id->lock,flags);
806 if(new_level == DEBUG_OFF_LEVEL){
807 id->level = DEBUG_OFF_LEVEL;
808 pr_info("%s: switched off\n",id->name);
809 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
810 pr_info("%s: level %i is out of range (%i - %i)\n",
811 id->name, new_level, 0, DEBUG_MAX_LEVEL);
812 } else {
813 id->level = new_level;
814 }
815 spin_unlock_irqrestore(&id->lock,flags);
816}
817EXPORT_SYMBOL(debug_set_level);
818
819/*
820 * proceed_active_entry:
821 * - set active entry to next in the ring buffer
822 */
823
824static inline void
825proceed_active_entry(debug_info_t * id)
826{
827 if ((id->active_entries[id->active_area] += id->entry_size)
828 > (PAGE_SIZE - id->entry_size)){
829 id->active_entries[id->active_area] = 0;
830 id->active_pages[id->active_area] =
831 (id->active_pages[id->active_area] + 1) %
832 id->pages_per_area;
833 }
834}
835
836/*
837 * proceed_active_area:
838 * - set active area to next in the ring buffer
839 */
840
841static inline void
842proceed_active_area(debug_info_t * id)
843{
844 id->active_area++;
845 id->active_area = id->active_area % id->nr_areas;
846}
847
848/*
849 * get_active_entry:
850 */
851
852static inline debug_entry_t*
853get_active_entry(debug_info_t * id)
854{
855 return (debug_entry_t *) (((char *) id->areas[id->active_area]
856 [id->active_pages[id->active_area]]) +
857 id->active_entries[id->active_area]);
858}
859
860/*
861 * debug_finish_entry:
862 * - set timestamp, caller address, cpu number etc.
863 */
864
865static inline void
866debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
867 int exception)
868{
869 active->id.stck = get_tod_clock_fast();
870 active->id.fields.cpuid = smp_processor_id();
871 active->caller = __builtin_return_address(0);
872 active->id.fields.exception = exception;
873 active->id.fields.level = level;
874 proceed_active_entry(id);
875 if(exception)
876 proceed_active_area(id);
877}
878
879static int debug_stoppable=1;
880static int debug_active=1;
881
882#define CTL_S390DBF_STOPPABLE 5678
883#define CTL_S390DBF_ACTIVE 5679
884
885/*
886 * proc handler for the running debug_active sysctl
887 * always allow read, allow write only if debug_stoppable is set or
888 * if debug_active is already off
889 */
890static int
891s390dbf_procactive(struct ctl_table *table, int write,
892 void __user *buffer, size_t *lenp, loff_t *ppos)
893{
894 if (!write || debug_stoppable || !debug_active)
895 return proc_dointvec(table, write, buffer, lenp, ppos);
896 else
897 return 0;
898}
899
900
901static struct ctl_table s390dbf_table[] = {
902 {
903 .procname = "debug_stoppable",
904 .data = &debug_stoppable,
905 .maxlen = sizeof(int),
906 .mode = S_IRUGO | S_IWUSR,
907 .proc_handler = proc_dointvec,
908 },
909 {
910 .procname = "debug_active",
911 .data = &debug_active,
912 .maxlen = sizeof(int),
913 .mode = S_IRUGO | S_IWUSR,
914 .proc_handler = s390dbf_procactive,
915 },
916 { }
917};
918
919static struct ctl_table s390dbf_dir_table[] = {
920 {
921 .procname = "s390dbf",
922 .maxlen = 0,
923 .mode = S_IRUGO | S_IXUGO,
924 .child = s390dbf_table,
925 },
926 { }
927};
928
929static struct ctl_table_header *s390dbf_sysctl_header;
930
931void
932debug_stop_all(void)
933{
934 if (debug_stoppable)
935 debug_active = 0;
936}
937EXPORT_SYMBOL(debug_stop_all);
938
939void debug_set_critical(void)
940{
941 debug_critical = 1;
942}
943
944/*
945 * debug_event_common:
946 * - write debug entry with given size
947 */
948
949debug_entry_t*
950debug_event_common(debug_info_t * id, int level, const void *buf, int len)
951{
952 unsigned long flags;
953 debug_entry_t *active;
954
955 if (!debug_active || !id->areas)
956 return NULL;
957 if (debug_critical) {
958 if (!spin_trylock_irqsave(&id->lock, flags))
959 return NULL;
960 } else
961 spin_lock_irqsave(&id->lock, flags);
962 active = get_active_entry(id);
963 memset(DEBUG_DATA(active), 0, id->buf_size);
964 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
965 debug_finish_entry(id, active, level, 0);
966 spin_unlock_irqrestore(&id->lock, flags);
967
968 return active;
969}
970EXPORT_SYMBOL(debug_event_common);
971
972/*
973 * debug_exception_common:
974 * - write debug entry with given size and switch to next debug area
975 */
976
977debug_entry_t
978*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
979{
980 unsigned long flags;
981 debug_entry_t *active;
982
983 if (!debug_active || !id->areas)
984 return NULL;
985 if (debug_critical) {
986 if (!spin_trylock_irqsave(&id->lock, flags))
987 return NULL;
988 } else
989 spin_lock_irqsave(&id->lock, flags);
990 active = get_active_entry(id);
991 memset(DEBUG_DATA(active), 0, id->buf_size);
992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
993 debug_finish_entry(id, active, level, 1);
994 spin_unlock_irqrestore(&id->lock, flags);
995
996 return active;
997}
998EXPORT_SYMBOL(debug_exception_common);
999
1000/*
1001 * counts arguments in format string for sprintf view
1002 */
1003
1004static inline int
1005debug_count_numargs(char *string)
1006{
1007 int numargs=0;
1008
1009 while(*string) {
1010 if(*string++=='%')
1011 numargs++;
1012 }
1013 return(numargs);
1014}
1015
1016/*
1017 * debug_sprintf_event:
1018 */
1019
1020debug_entry_t*
1021__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1022{
1023 va_list ap;
1024 int numargs,idx;
1025 unsigned long flags;
1026 debug_sprintf_entry_t *curr_event;
1027 debug_entry_t *active;
1028
1029 if (!debug_active || !id->areas)
1030 return NULL;
1031 numargs=debug_count_numargs(string);
1032
1033 if (debug_critical) {
1034 if (!spin_trylock_irqsave(&id->lock, flags))
1035 return NULL;
1036 } else
1037 spin_lock_irqsave(&id->lock, flags);
1038 active = get_active_entry(id);
1039 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1040 va_start(ap,string);
1041 curr_event->string=string;
1042 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1043 curr_event->args[idx]=va_arg(ap,long);
1044 va_end(ap);
1045 debug_finish_entry(id, active, level, 0);
1046 spin_unlock_irqrestore(&id->lock, flags);
1047
1048 return active;
1049}
1050EXPORT_SYMBOL(__debug_sprintf_event);
1051
1052/*
1053 * debug_sprintf_exception:
1054 */
1055
1056debug_entry_t*
1057__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1058{
1059 va_list ap;
1060 int numargs,idx;
1061 unsigned long flags;
1062 debug_sprintf_entry_t *curr_event;
1063 debug_entry_t *active;
1064
1065 if (!debug_active || !id->areas)
1066 return NULL;
1067
1068 numargs=debug_count_numargs(string);
1069
1070 if (debug_critical) {
1071 if (!spin_trylock_irqsave(&id->lock, flags))
1072 return NULL;
1073 } else
1074 spin_lock_irqsave(&id->lock, flags);
1075 active = get_active_entry(id);
1076 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1077 va_start(ap,string);
1078 curr_event->string=string;
1079 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1080 curr_event->args[idx]=va_arg(ap,long);
1081 va_end(ap);
1082 debug_finish_entry(id, active, level, 1);
1083 spin_unlock_irqrestore(&id->lock, flags);
1084
1085 return active;
1086}
1087EXPORT_SYMBOL(__debug_sprintf_exception);
1088
1089/*
1090 * debug_register_view:
1091 */
1092
1093int
1094debug_register_view(debug_info_t * id, struct debug_view *view)
1095{
1096 int rc = 0;
1097 int i;
1098 unsigned long flags;
1099 umode_t mode;
1100 struct dentry *pde;
1101
1102 if (!id)
1103 goto out;
1104 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1105 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1106 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1107 if (!view->input_proc)
1108 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1109 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1110 id , &debug_file_ops);
1111 if (!pde){
1112 pr_err("Registering view %s/%s failed due to out of "
1113 "memory\n", id->name,view->name);
1114 rc = -1;
1115 goto out;
1116 }
1117 spin_lock_irqsave(&id->lock, flags);
1118 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1119 if (!id->views[i])
1120 break;
1121 }
1122 if (i == DEBUG_MAX_VIEWS) {
1123 pr_err("Registering view %s/%s would exceed the maximum "
1124 "number of views %i\n", id->name, view->name, i);
1125 rc = -1;
1126 } else {
1127 id->views[i] = view;
1128 id->debugfs_entries[i] = pde;
1129 }
1130 spin_unlock_irqrestore(&id->lock, flags);
1131 if (rc)
1132 debugfs_remove(pde);
1133out:
1134 return rc;
1135}
1136EXPORT_SYMBOL(debug_register_view);
1137
1138/*
1139 * debug_unregister_view:
1140 */
1141
1142int
1143debug_unregister_view(debug_info_t * id, struct debug_view *view)
1144{
1145 struct dentry *dentry = NULL;
1146 unsigned long flags;
1147 int i, rc = 0;
1148
1149 if (!id)
1150 goto out;
1151 spin_lock_irqsave(&id->lock, flags);
1152 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1153 if (id->views[i] == view)
1154 break;
1155 }
1156 if (i == DEBUG_MAX_VIEWS)
1157 rc = -1;
1158 else {
1159 dentry = id->debugfs_entries[i];
1160 id->views[i] = NULL;
1161 id->debugfs_entries[i] = NULL;
1162 }
1163 spin_unlock_irqrestore(&id->lock, flags);
1164 debugfs_remove(dentry);
1165out:
1166 return rc;
1167}
1168EXPORT_SYMBOL(debug_unregister_view);
1169
1170static inline char *
1171debug_get_user_string(const char __user *user_buf, size_t user_len)
1172{
1173 char* buffer;
1174
1175 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1176 if (!buffer)
1177 return ERR_PTR(-ENOMEM);
1178 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1179 kfree(buffer);
1180 return ERR_PTR(-EFAULT);
1181 }
1182 /* got the string, now strip linefeed. */
1183 if (buffer[user_len - 1] == '\n')
1184 buffer[user_len - 1] = 0;
1185 else
1186 buffer[user_len] = 0;
1187 return buffer;
1188}
1189
1190static inline int
1191debug_get_uint(char *buf)
1192{
1193 int rc;
1194
1195 buf = skip_spaces(buf);
1196 rc = simple_strtoul(buf, &buf, 10);
1197 if(*buf){
1198 rc = -EINVAL;
1199 }
1200 return rc;
1201}
1202
1203/*
1204 * functions for debug-views
1205 ***********************************
1206*/
1207
1208/*
1209 * prints out actual debug level
1210 */
1211
1212static int
1213debug_prolog_pages_fn(debug_info_t * id,
1214 struct debug_view *view, char *out_buf)
1215{
1216 return sprintf(out_buf, "%i\n", id->pages_per_area);
1217}
1218
1219/*
1220 * reads new size (number of pages per debug area)
1221 */
1222
1223static int
1224debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1225 struct file *file, const char __user *user_buf,
1226 size_t user_len, loff_t * offset)
1227{
1228 char *str;
1229 int rc,new_pages;
1230
1231 if (user_len > 0x10000)
1232 user_len = 0x10000;
1233 if (*offset != 0){
1234 rc = -EPIPE;
1235 goto out;
1236 }
1237 str = debug_get_user_string(user_buf,user_len);
1238 if(IS_ERR(str)){
1239 rc = PTR_ERR(str);
1240 goto out;
1241 }
1242 new_pages = debug_get_uint(str);
1243 if(new_pages < 0){
1244 rc = -EINVAL;
1245 goto free_str;
1246 }
1247 rc = debug_set_size(id,id->nr_areas, new_pages);
1248 if(rc != 0){
1249 rc = -EINVAL;
1250 goto free_str;
1251 }
1252 rc = user_len;
1253free_str:
1254 kfree(str);
1255out:
1256 *offset += user_len;
1257 return rc; /* number of input characters */
1258}
1259
1260/*
1261 * prints out actual debug level
1262 */
1263
1264static int
1265debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1266{
1267 int rc = 0;
1268
1269 if(id->level == DEBUG_OFF_LEVEL) {
1270 rc = sprintf(out_buf,"-\n");
1271 }
1272 else {
1273 rc = sprintf(out_buf, "%i\n", id->level);
1274 }
1275 return rc;
1276}
1277
1278/*
1279 * reads new debug level
1280 */
1281
1282static int
1283debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1284 struct file *file, const char __user *user_buf,
1285 size_t user_len, loff_t * offset)
1286{
1287 char *str;
1288 int rc,new_level;
1289
1290 if (user_len > 0x10000)
1291 user_len = 0x10000;
1292 if (*offset != 0){
1293 rc = -EPIPE;
1294 goto out;
1295 }
1296 str = debug_get_user_string(user_buf,user_len);
1297 if(IS_ERR(str)){
1298 rc = PTR_ERR(str);
1299 goto out;
1300 }
1301 if(str[0] == '-'){
1302 debug_set_level(id, DEBUG_OFF_LEVEL);
1303 rc = user_len;
1304 goto free_str;
1305 } else {
1306 new_level = debug_get_uint(str);
1307 }
1308 if(new_level < 0) {
1309 pr_warn("%s is not a valid level for a debug feature\n", str);
1310 rc = -EINVAL;
1311 } else {
1312 debug_set_level(id, new_level);
1313 rc = user_len;
1314 }
1315free_str:
1316 kfree(str);
1317out:
1318 *offset += user_len;
1319 return rc; /* number of input characters */
1320}
1321
1322
1323/*
1324 * flushes debug areas
1325 */
1326
1327static void debug_flush(debug_info_t* id, int area)
1328{
1329 unsigned long flags;
1330 int i,j;
1331
1332 if(!id || !id->areas)
1333 return;
1334 spin_lock_irqsave(&id->lock,flags);
1335 if(area == DEBUG_FLUSH_ALL){
1336 id->active_area = 0;
1337 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1338 for (i = 0; i < id->nr_areas; i++) {
1339 id->active_pages[i] = 0;
1340 for(j = 0; j < id->pages_per_area; j++) {
1341 memset(id->areas[i][j], 0, PAGE_SIZE);
1342 }
1343 }
1344 } else if(area >= 0 && area < id->nr_areas) {
1345 id->active_entries[area] = 0;
1346 id->active_pages[area] = 0;
1347 for(i = 0; i < id->pages_per_area; i++) {
1348 memset(id->areas[area][i],0,PAGE_SIZE);
1349 }
1350 }
1351 spin_unlock_irqrestore(&id->lock,flags);
1352}
1353
1354/*
1355 * view function: flushes debug areas
1356 */
1357
1358static int
1359debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1360 struct file *file, const char __user *user_buf,
1361 size_t user_len, loff_t * offset)
1362{
1363 char input_buf[1];
1364 int rc = user_len;
1365
1366 if (user_len > 0x10000)
1367 user_len = 0x10000;
1368 if (*offset != 0){
1369 rc = -EPIPE;
1370 goto out;
1371 }
1372 if (copy_from_user(input_buf, user_buf, 1)){
1373 rc = -EFAULT;
1374 goto out;
1375 }
1376 if(input_buf[0] == '-') {
1377 debug_flush(id, DEBUG_FLUSH_ALL);
1378 goto out;
1379 }
1380 if (isdigit(input_buf[0])) {
1381 int area = ((int) input_buf[0] - (int) '0');
1382 debug_flush(id, area);
1383 goto out;
1384 }
1385
1386 pr_info("Flushing debug data failed because %c is not a valid "
1387 "area\n", input_buf[0]);
1388
1389out:
1390 *offset += user_len;
1391 return rc; /* number of input characters */
1392}
1393
1394/*
1395 * prints debug header in raw format
1396 */
1397
1398static int
1399debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1400 int area, debug_entry_t * entry, char *out_buf)
1401{
1402 int rc;
1403
1404 rc = sizeof(debug_entry_t);
1405 memcpy(out_buf,entry,sizeof(debug_entry_t));
1406 return rc;
1407}
1408
1409/*
1410 * prints debug data in raw format
1411 */
1412
1413static int
1414debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1415 char *out_buf, const char *in_buf)
1416{
1417 int rc;
1418
1419 rc = id->buf_size;
1420 memcpy(out_buf, in_buf, id->buf_size);
1421 return rc;
1422}
1423
1424/*
1425 * prints debug data in hex/ascii format
1426 */
1427
1428static int
1429debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1430 char *out_buf, const char *in_buf)
1431{
1432 int i, rc = 0;
1433
1434 for (i = 0; i < id->buf_size; i++) {
1435 rc += sprintf(out_buf + rc, "%02x ",
1436 ((unsigned char *) in_buf)[i]);
1437 }
1438 rc += sprintf(out_buf + rc, "| ");
1439 for (i = 0; i < id->buf_size; i++) {
1440 unsigned char c = in_buf[i];
1441 if (isascii(c) && isprint(c))
1442 rc += sprintf(out_buf + rc, "%c", c);
1443 else
1444 rc += sprintf(out_buf + rc, ".");
1445 }
1446 rc += sprintf(out_buf + rc, "\n");
1447 return rc;
1448}
1449
1450/*
1451 * prints header for debug entry
1452 */
1453
1454int
1455debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1456 int area, debug_entry_t * entry, char *out_buf)
1457{
1458 struct timespec64 time_spec;
1459 char *except_str;
1460 unsigned long caller;
1461 int rc = 0;
1462 unsigned int level;
1463
1464 level = entry->id.fields.level;
1465 stck_to_timespec64(entry->id.stck, &time_spec);
1466
1467 if (entry->id.fields.exception)
1468 except_str = "*";
1469 else
1470 except_str = "-";
1471 caller = (unsigned long) entry->caller;
1472 rc += sprintf(out_buf, "%02i %011lld:%06lu %1u %1s %02i %p ",
1473 area, (long long)time_spec.tv_sec,
1474 time_spec.tv_nsec / 1000, level, except_str,
1475 entry->id.fields.cpuid, (void *)caller);
1476 return rc;
1477}
1478EXPORT_SYMBOL(debug_dflt_header_fn);
1479
1480/*
1481 * prints debug data sprintf-formated:
1482 * debug_sprinf_event/exception calls must be used together with this view
1483 */
1484
1485#define DEBUG_SPRINTF_MAX_ARGS 10
1486
1487static int
1488debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1489 char *out_buf, debug_sprintf_entry_t *curr_event)
1490{
1491 int num_longs, num_used_args = 0,i, rc = 0;
1492 int index[DEBUG_SPRINTF_MAX_ARGS];
1493
1494 /* count of longs fit into one entry */
1495 num_longs = id->buf_size / sizeof(long);
1496
1497 if(num_longs < 1)
1498 goto out; /* bufsize of entry too small */
1499 if(num_longs == 1) {
1500 /* no args, we use only the string */
1501 strcpy(out_buf, curr_event->string);
1502 rc = strlen(curr_event->string);
1503 goto out;
1504 }
1505
1506 /* number of arguments used for sprintf (without the format string) */
1507 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1508
1509 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1510
1511 for(i = 0; i < num_used_args; i++)
1512 index[i] = i;
1513
1514 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1515 curr_event->args[index[1]], curr_event->args[index[2]],
1516 curr_event->args[index[3]], curr_event->args[index[4]],
1517 curr_event->args[index[5]], curr_event->args[index[6]],
1518 curr_event->args[index[7]], curr_event->args[index[8]],
1519 curr_event->args[index[9]]);
1520
1521out:
1522
1523 return rc;
1524}
1525
1526/*
1527 * debug_init:
1528 * - is called exactly once to initialize the debug feature
1529 */
1530static int __init debug_init(void)
1531{
1532 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1533 mutex_lock(&debug_mutex);
1534 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1535 initialized = 1;
1536 mutex_unlock(&debug_mutex);
1537 return 0;
1538}
1539postcore_initcall(debug_init);