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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 * arch/s390/kernel/debug.c
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2012
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 <asm/uaccess.h>
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/debugfs.h>
28
29#include <asm/debug.h>
30
31#define DEBUG_PROLOG_ENTRY -1
32
33#define ALL_AREAS 0 /* copy all debug areas */
34#define NO_AREAS 1 /* copy no debug areas */
35
36/* typedefs */
37
38typedef struct file_private_info {
39 loff_t offset; /* offset of last read in file */
40 int act_area; /* number of last formated area */
41 int act_page; /* act page in given area */
42 int act_entry; /* last formated entry (offset */
43 /* relative to beginning of last */
44 /* formated page) */
45 size_t act_entry_offset; /* up to this offset we copied */
46 /* in last read the last formated */
47 /* entry to userland */
48 char temp_buf[2048]; /* buffer for output */
49 debug_info_t *debug_info_org; /* original debug information */
50 debug_info_t *debug_info_snap; /* snapshot of debug information */
51 struct debug_view *view; /* used view of debug info */
52} file_private_info_t;
53
54typedef struct
55{
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[0];
64} debug_sprintf_entry_t;
65
66
67/* internal function prototyes */
68
69static int debug_init(void);
70static ssize_t debug_output(struct file *file, char __user *user_buf,
71 size_t user_len, loff_t * offset);
72static ssize_t debug_input(struct file *file, const char __user *user_buf,
73 size_t user_len, loff_t * offset);
74static int debug_open(struct inode *inode, struct file *file);
75static int debug_close(struct inode *inode, struct file *file);
76static debug_info_t *debug_info_create(const char *name, int pages_per_area,
77 int nr_areas, int buf_size, umode_t mode);
78static void debug_info_get(debug_info_t *);
79static void debug_info_put(debug_info_t *);
80static int debug_prolog_level_fn(debug_info_t * id,
81 struct debug_view *view, char *out_buf);
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);
87static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
88 struct file *file, const char __user *user_buf,
89 size_t user_buf_size, loff_t * offset);
90static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
91 struct file *file, const char __user *user_buf,
92 size_t user_buf_size, loff_t * offset);
93static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
94 char *out_buf, const char *in_buf);
95static int debug_raw_format_fn(debug_info_t * id,
96 struct debug_view *view, char *out_buf,
97 const char *in_buf);
98static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
99 int area, debug_entry_t * entry, char *out_buf);
100
101static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
102 char *out_buf, debug_sprintf_entry_t *curr_event);
103
104/* globals */
105
106struct debug_view debug_raw_view = {
107 "raw",
108 NULL,
109 &debug_raw_header_fn,
110 &debug_raw_format_fn,
111 NULL,
112 NULL
113};
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};
123
124static struct debug_view debug_level_view = {
125 "level",
126 &debug_prolog_level_fn,
127 NULL,
128 NULL,
129 &debug_input_level_fn,
130 NULL
131};
132
133static struct debug_view debug_pages_view = {
134 "pages",
135 &debug_prolog_pages_fn,
136 NULL,
137 NULL,
138 &debug_input_pages_fn,
139 NULL
140};
141
142static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149};
150
151struct debug_view debug_sprintf_view = {
152 "sprintf",
153 NULL,
154 &debug_dflt_header_fn,
155 (debug_format_proc_t*)&debug_sprintf_format_fn,
156 NULL,
157 NULL
158};
159
160/* used by dump analysis tools to determine version of debug feature */
161static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
162
163/* static globals */
164
165static debug_info_t *debug_area_first = NULL;
166static debug_info_t *debug_area_last = NULL;
167static DEFINE_MUTEX(debug_mutex);
168
169static int initialized;
170static int debug_critical;
171
172static const struct file_operations debug_file_ops = {
173 .owner = THIS_MODULE,
174 .read = debug_output,
175 .write = debug_input,
176 .open = debug_open,
177 .release = debug_close,
178 .llseek = no_llseek,
179};
180
181static struct dentry *debug_debugfs_root_entry;
182
183/* functions */
184
185/*
186 * debug_areas_alloc
187 * - Debug areas are implemented as a threedimensonal array:
188 * areas[areanumber][pagenumber][pageoffset]
189 */
190
191static debug_entry_t***
192debug_areas_alloc(int pages_per_area, int nr_areas)
193{
194 debug_entry_t*** areas;
195 int i,j;
196
197 areas = kmalloc(nr_areas *
198 sizeof(debug_entry_t**),
199 GFP_KERNEL);
200 if (!areas)
201 goto fail_malloc_areas;
202 for (i = 0; i < nr_areas; i++) {
203 areas[i] = kmalloc(pages_per_area *
204 sizeof(debug_entry_t*),GFP_KERNEL);
205 if (!areas[i]) {
206 goto fail_malloc_areas2;
207 }
208 for(j = 0; j < pages_per_area; j++) {
209 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
210 if(!areas[i][j]) {
211 for(j--; j >=0 ; j--) {
212 kfree(areas[i][j]);
213 }
214 kfree(areas[i]);
215 goto fail_malloc_areas2;
216 }
217 }
218 }
219 return areas;
220
221fail_malloc_areas2:
222 for(i--; i >= 0; i--){
223 for(j=0; j < pages_per_area;j++){
224 kfree(areas[i][j]);
225 }
226 kfree(areas[i]);
227 }
228 kfree(areas);
229fail_malloc_areas:
230 return NULL;
231
232}
233
234
235/*
236 * debug_info_alloc
237 * - alloc new debug-info
238 */
239
240static debug_info_t*
241debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
242 int buf_size, int level, int mode)
243{
244 debug_info_t* rc;
245
246 /* alloc everything */
247
248 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
249 if(!rc)
250 goto fail_malloc_rc;
251 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
252 if(!rc->active_entries)
253 goto fail_malloc_active_entries;
254 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
255 if(!rc->active_pages)
256 goto fail_malloc_active_pages;
257 if((mode == ALL_AREAS) && (pages_per_area != 0)){
258 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
259 if(!rc->areas)
260 goto fail_malloc_areas;
261 } else {
262 rc->areas = NULL;
263 }
264
265 /* initialize members */
266
267 spin_lock_init(&rc->lock);
268 rc->pages_per_area = pages_per_area;
269 rc->nr_areas = nr_areas;
270 rc->active_area = 0;
271 rc->level = level;
272 rc->buf_size = buf_size;
273 rc->entry_size = sizeof(debug_entry_t) + buf_size;
274 strlcpy(rc->name, name, sizeof(rc->name));
275 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
276 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
277 sizeof(struct dentry*));
278 atomic_set(&(rc->ref_count), 0);
279
280 return rc;
281
282fail_malloc_areas:
283 kfree(rc->active_pages);
284fail_malloc_active_pages:
285 kfree(rc->active_entries);
286fail_malloc_active_entries:
287 kfree(rc);
288fail_malloc_rc:
289 return NULL;
290}
291
292/*
293 * debug_areas_free
294 * - free all debug areas
295 */
296
297static void
298debug_areas_free(debug_info_t* db_info)
299{
300 int i,j;
301
302 if(!db_info->areas)
303 return;
304 for (i = 0; i < db_info->nr_areas; i++) {
305 for(j = 0; j < db_info->pages_per_area; j++) {
306 kfree(db_info->areas[i][j]);
307 }
308 kfree(db_info->areas[i]);
309 }
310 kfree(db_info->areas);
311 db_info->areas = NULL;
312}
313
314/*
315 * debug_info_free
316 * - free memory debug-info
317 */
318
319static void
320debug_info_free(debug_info_t* db_info){
321 debug_areas_free(db_info);
322 kfree(db_info->active_entries);
323 kfree(db_info->active_pages);
324 kfree(db_info);
325}
326
327/*
328 * debug_info_create
329 * - create new debug-info
330 */
331
332static debug_info_t*
333debug_info_create(const char *name, int pages_per_area, int nr_areas,
334 int buf_size, umode_t mode)
335{
336 debug_info_t* rc;
337
338 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
339 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
340 if(!rc)
341 goto out;
342
343 rc->mode = mode & ~S_IFMT;
344
345 /* create root directory */
346 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
347 debug_debugfs_root_entry);
348
349 /* append new element to linked list */
350 if (!debug_area_first) {
351 /* first element in list */
352 debug_area_first = rc;
353 rc->prev = NULL;
354 } else {
355 /* append element to end of list */
356 debug_area_last->next = rc;
357 rc->prev = debug_area_last;
358 }
359 debug_area_last = rc;
360 rc->next = NULL;
361
362 debug_info_get(rc);
363out:
364 return rc;
365}
366
367/*
368 * debug_info_copy
369 * - copy debug-info
370 */
371
372static debug_info_t*
373debug_info_copy(debug_info_t* in, int mode)
374{
375 int i,j;
376 debug_info_t* rc;
377 unsigned long flags;
378
379 /* get a consistent copy of the debug areas */
380 do {
381 rc = debug_info_alloc(in->name, in->pages_per_area,
382 in->nr_areas, in->buf_size, in->level, mode);
383 spin_lock_irqsave(&in->lock, flags);
384 if(!rc)
385 goto out;
386 /* has something changed in the meantime ? */
387 if((rc->pages_per_area == in->pages_per_area) &&
388 (rc->nr_areas == in->nr_areas)) {
389 break;
390 }
391 spin_unlock_irqrestore(&in->lock, flags);
392 debug_info_free(rc);
393 } while (1);
394
395 if (mode == NO_AREAS)
396 goto out;
397
398 for(i = 0; i < in->nr_areas; i++){
399 for(j = 0; j < in->pages_per_area; j++) {
400 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
401 }
402 }
403out:
404 spin_unlock_irqrestore(&in->lock, flags);
405 return rc;
406}
407
408/*
409 * debug_info_get
410 * - increments reference count for debug-info
411 */
412
413static void
414debug_info_get(debug_info_t * db_info)
415{
416 if (db_info)
417 atomic_inc(&db_info->ref_count);
418}
419
420/*
421 * debug_info_put:
422 * - decreases reference count for debug-info and frees it if necessary
423 */
424
425static void
426debug_info_put(debug_info_t *db_info)
427{
428 int i;
429
430 if (!db_info)
431 return;
432 if (atomic_dec_and_test(&db_info->ref_count)) {
433 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
434 if (!db_info->views[i])
435 continue;
436 debugfs_remove(db_info->debugfs_entries[i]);
437 }
438 debugfs_remove(db_info->debugfs_root_entry);
439 if(db_info == debug_area_first)
440 debug_area_first = db_info->next;
441 if(db_info == debug_area_last)
442 debug_area_last = db_info->prev;
443 if(db_info->prev) db_info->prev->next = db_info->next;
444 if(db_info->next) db_info->next->prev = db_info->prev;
445 debug_info_free(db_info);
446 }
447}
448
449/*
450 * debug_format_entry:
451 * - format one debug entry and return size of formated data
452 */
453
454static int
455debug_format_entry(file_private_info_t *p_info)
456{
457 debug_info_t *id_snap = p_info->debug_info_snap;
458 struct debug_view *view = p_info->view;
459 debug_entry_t *act_entry;
460 size_t len = 0;
461 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
462 /* print prolog */
463 if (view->prolog_proc)
464 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
465 goto out;
466 }
467 if (!id_snap->areas) /* this is true, if we have a prolog only view */
468 goto out; /* or if 'pages_per_area' is 0 */
469 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
470 [p_info->act_page] + p_info->act_entry);
471
472 if (act_entry->id.stck == 0LL)
473 goto out; /* empty entry */
474 if (view->header_proc)
475 len += view->header_proc(id_snap, view, p_info->act_area,
476 act_entry, p_info->temp_buf + len);
477 if (view->format_proc)
478 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
479 DEBUG_DATA(act_entry));
480out:
481 return len;
482}
483
484/*
485 * debug_next_entry:
486 * - goto next entry in p_info
487 */
488
489static inline int
490debug_next_entry(file_private_info_t *p_info)
491{
492 debug_info_t *id;
493
494 id = p_info->debug_info_snap;
495 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
496 p_info->act_entry = 0;
497 p_info->act_page = 0;
498 goto out;
499 }
500 if(!id->areas)
501 return 1;
502 p_info->act_entry += id->entry_size;
503 /* switch to next page, if we reached the end of the page */
504 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
505 /* next page */
506 p_info->act_entry = 0;
507 p_info->act_page += 1;
508 if((p_info->act_page % id->pages_per_area) == 0) {
509 /* next area */
510 p_info->act_area++;
511 p_info->act_page=0;
512 }
513 if(p_info->act_area >= id->nr_areas)
514 return 1;
515 }
516out:
517 return 0;
518}
519
520/*
521 * debug_output:
522 * - called for user read()
523 * - copies formated debug entries to the user buffer
524 */
525
526static ssize_t
527debug_output(struct file *file, /* file descriptor */
528 char __user *user_buf, /* user buffer */
529 size_t len, /* length of buffer */
530 loff_t *offset) /* offset in the file */
531{
532 size_t count = 0;
533 size_t entry_offset;
534 file_private_info_t *p_info;
535
536 p_info = ((file_private_info_t *) file->private_data);
537 if (*offset != p_info->offset)
538 return -EPIPE;
539 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
540 return 0;
541 entry_offset = p_info->act_entry_offset;
542 while(count < len){
543 int formatted_line_size;
544 int formatted_line_residue;
545 int user_buf_residue;
546 size_t copy_size;
547
548 formatted_line_size = debug_format_entry(p_info);
549 formatted_line_residue = formatted_line_size - entry_offset;
550 user_buf_residue = len-count;
551 copy_size = min(user_buf_residue, formatted_line_residue);
552 if(copy_size){
553 if (copy_to_user(user_buf + count, p_info->temp_buf
554 + entry_offset, copy_size))
555 return -EFAULT;
556 count += copy_size;
557 entry_offset += copy_size;
558 }
559 if(copy_size == formatted_line_residue){
560 entry_offset = 0;
561 if(debug_next_entry(p_info))
562 goto out;
563 }
564 }
565out:
566 p_info->offset = *offset + count;
567 p_info->act_entry_offset = entry_offset;
568 *offset = p_info->offset;
569 return count;
570}
571
572/*
573 * debug_input:
574 * - called for user write()
575 * - calls input function of view
576 */
577
578static ssize_t
579debug_input(struct file *file, const char __user *user_buf, size_t length,
580 loff_t *offset)
581{
582 int rc = 0;
583 file_private_info_t *p_info;
584
585 mutex_lock(&debug_mutex);
586 p_info = ((file_private_info_t *) file->private_data);
587 if (p_info->view->input_proc)
588 rc = p_info->view->input_proc(p_info->debug_info_org,
589 p_info->view, file, user_buf,
590 length, offset);
591 else
592 rc = -EPERM;
593 mutex_unlock(&debug_mutex);
594 return rc; /* number of input characters */
595}
596
597/*
598 * debug_open:
599 * - called for user open()
600 * - copies formated output to private_data area of the file
601 * handle
602 */
603
604static int
605debug_open(struct inode *inode, struct file *file)
606{
607 int i, rc = 0;
608 file_private_info_t *p_info;
609 debug_info_t *debug_info, *debug_info_snapshot;
610
611 mutex_lock(&debug_mutex);
612 debug_info = file->f_path.dentry->d_inode->i_private;
613 /* find debug view */
614 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
615 if (!debug_info->views[i])
616 continue;
617 else if (debug_info->debugfs_entries[i] ==
618 file->f_path.dentry) {
619 goto found; /* found view ! */
620 }
621 }
622 /* no entry found */
623 rc = -EINVAL;
624 goto out;
625
626found:
627
628 /* Make snapshot of current debug areas to get it consistent. */
629 /* To copy all the areas is only needed, if we have a view which */
630 /* formats the debug areas. */
631
632 if(!debug_info->views[i]->format_proc &&
633 !debug_info->views[i]->header_proc){
634 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
635 } else {
636 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
637 }
638
639 if(!debug_info_snapshot){
640 rc = -ENOMEM;
641 goto out;
642 }
643 p_info = kmalloc(sizeof(file_private_info_t),
644 GFP_KERNEL);
645 if(!p_info){
646 debug_info_free(debug_info_snapshot);
647 rc = -ENOMEM;
648 goto out;
649 }
650 p_info->offset = 0;
651 p_info->debug_info_snap = debug_info_snapshot;
652 p_info->debug_info_org = debug_info;
653 p_info->view = debug_info->views[i];
654 p_info->act_area = 0;
655 p_info->act_page = 0;
656 p_info->act_entry = DEBUG_PROLOG_ENTRY;
657 p_info->act_entry_offset = 0;
658 file->private_data = p_info;
659 debug_info_get(debug_info);
660 nonseekable_open(inode, file);
661out:
662 mutex_unlock(&debug_mutex);
663 return rc;
664}
665
666/*
667 * debug_close:
668 * - called for user close()
669 * - deletes private_data area of the file handle
670 */
671
672static int
673debug_close(struct inode *inode, struct file *file)
674{
675 file_private_info_t *p_info;
676 p_info = (file_private_info_t *) file->private_data;
677 if(p_info->debug_info_snap)
678 debug_info_free(p_info->debug_info_snap);
679 debug_info_put(p_info->debug_info_org);
680 kfree(file->private_data);
681 return 0; /* success */
682}
683
684/*
685 * debug_register_mode:
686 * - Creates and initializes debug area for the caller
687 * The mode parameter allows to specify access rights for the s390dbf files
688 * - Returns handle for debug area
689 */
690
691debug_info_t *debug_register_mode(const char *name, int pages_per_area,
692 int nr_areas, int buf_size, umode_t mode,
693 uid_t uid, gid_t gid)
694{
695 debug_info_t *rc = NULL;
696
697 /* Since debugfs currently does not support uid/gid other than root, */
698 /* we do not allow gid/uid != 0 until we get support for that. */
699 if ((uid != 0) || (gid != 0))
700 pr_warning("Root becomes the owner of all s390dbf files "
701 "in sysfs\n");
702 BUG_ON(!initialized);
703 mutex_lock(&debug_mutex);
704
705 /* create new debug_info */
706
707 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
708 if(!rc)
709 goto out;
710 debug_register_view(rc, &debug_level_view);
711 debug_register_view(rc, &debug_flush_view);
712 debug_register_view(rc, &debug_pages_view);
713out:
714 if (!rc){
715 pr_err("Registering debug feature %s failed\n", name);
716 }
717 mutex_unlock(&debug_mutex);
718 return rc;
719}
720EXPORT_SYMBOL(debug_register_mode);
721
722/*
723 * debug_register:
724 * - creates and initializes debug area for the caller
725 * - returns handle for debug area
726 */
727
728debug_info_t *debug_register(const char *name, int pages_per_area,
729 int nr_areas, int buf_size)
730{
731 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
732 S_IRUSR | S_IWUSR, 0, 0);
733}
734
735/*
736 * debug_unregister:
737 * - give back debug area
738 */
739
740void
741debug_unregister(debug_info_t * id)
742{
743 if (!id)
744 goto out;
745 mutex_lock(&debug_mutex);
746 debug_info_put(id);
747 mutex_unlock(&debug_mutex);
748
749out:
750 return;
751}
752
753/*
754 * debug_set_size:
755 * - set area size (number of pages) and number of areas
756 */
757static int
758debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
759{
760 unsigned long flags;
761 debug_entry_t *** new_areas;
762 int rc=0;
763
764 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
765 return -EINVAL;
766 if(pages_per_area > 0){
767 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
768 if(!new_areas) {
769 pr_info("Allocating memory for %i pages failed\n",
770 pages_per_area);
771 rc = -ENOMEM;
772 goto out;
773 }
774 } else {
775 new_areas = NULL;
776 }
777 spin_lock_irqsave(&id->lock,flags);
778 debug_areas_free(id);
779 id->areas = new_areas;
780 id->nr_areas = nr_areas;
781 id->pages_per_area = pages_per_area;
782 id->active_area = 0;
783 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
784 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
785 spin_unlock_irqrestore(&id->lock,flags);
786 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
787out:
788 return rc;
789}
790
791/*
792 * debug_set_level:
793 * - set actual debug level
794 */
795
796void
797debug_set_level(debug_info_t* id, int new_level)
798{
799 unsigned long flags;
800 if(!id)
801 return;
802 spin_lock_irqsave(&id->lock,flags);
803 if(new_level == DEBUG_OFF_LEVEL){
804 id->level = DEBUG_OFF_LEVEL;
805 pr_info("%s: switched off\n",id->name);
806 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
807 pr_info("%s: level %i is out of range (%i - %i)\n",
808 id->name, new_level, 0, DEBUG_MAX_LEVEL);
809 } else {
810 id->level = new_level;
811 }
812 spin_unlock_irqrestore(&id->lock,flags);
813}
814
815
816/*
817 * proceed_active_entry:
818 * - set active entry to next in the ring buffer
819 */
820
821static inline void
822proceed_active_entry(debug_info_t * id)
823{
824 if ((id->active_entries[id->active_area] += id->entry_size)
825 > (PAGE_SIZE - id->entry_size)){
826 id->active_entries[id->active_area] = 0;
827 id->active_pages[id->active_area] =
828 (id->active_pages[id->active_area] + 1) %
829 id->pages_per_area;
830 }
831}
832
833/*
834 * proceed_active_area:
835 * - set active area to next in the ring buffer
836 */
837
838static inline void
839proceed_active_area(debug_info_t * id)
840{
841 id->active_area++;
842 id->active_area = id->active_area % id->nr_areas;
843}
844
845/*
846 * get_active_entry:
847 */
848
849static inline debug_entry_t*
850get_active_entry(debug_info_t * id)
851{
852 return (debug_entry_t *) (((char *) id->areas[id->active_area]
853 [id->active_pages[id->active_area]]) +
854 id->active_entries[id->active_area]);
855}
856
857/*
858 * debug_finish_entry:
859 * - set timestamp, caller address, cpu number etc.
860 */
861
862static inline void
863debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
864 int exception)
865{
866 active->id.stck = get_clock();
867 active->id.fields.cpuid = smp_processor_id();
868 active->caller = __builtin_return_address(0);
869 active->id.fields.exception = exception;
870 active->id.fields.level = level;
871 proceed_active_entry(id);
872 if(exception)
873 proceed_active_area(id);
874}
875
876static int debug_stoppable=1;
877static int debug_active=1;
878
879#define CTL_S390DBF_STOPPABLE 5678
880#define CTL_S390DBF_ACTIVE 5679
881
882/*
883 * proc handler for the running debug_active sysctl
884 * always allow read, allow write only if debug_stoppable is set or
885 * if debug_active is already off
886 */
887static int
888s390dbf_procactive(ctl_table *table, int write,
889 void __user *buffer, size_t *lenp, loff_t *ppos)
890{
891 if (!write || debug_stoppable || !debug_active)
892 return proc_dointvec(table, write, buffer, lenp, ppos);
893 else
894 return 0;
895}
896
897
898static struct ctl_table s390dbf_table[] = {
899 {
900 .procname = "debug_stoppable",
901 .data = &debug_stoppable,
902 .maxlen = sizeof(int),
903 .mode = S_IRUGO | S_IWUSR,
904 .proc_handler = proc_dointvec,
905 },
906 {
907 .procname = "debug_active",
908 .data = &debug_active,
909 .maxlen = sizeof(int),
910 .mode = S_IRUGO | S_IWUSR,
911 .proc_handler = s390dbf_procactive,
912 },
913 { }
914};
915
916static struct ctl_table s390dbf_dir_table[] = {
917 {
918 .procname = "s390dbf",
919 .maxlen = 0,
920 .mode = S_IRUGO | S_IXUGO,
921 .child = s390dbf_table,
922 },
923 { }
924};
925
926static struct ctl_table_header *s390dbf_sysctl_header;
927
928void
929debug_stop_all(void)
930{
931 if (debug_stoppable)
932 debug_active = 0;
933}
934
935
936void debug_set_critical(void)
937{
938 debug_critical = 1;
939}
940
941/*
942 * debug_event_common:
943 * - write debug entry with given size
944 */
945
946debug_entry_t*
947debug_event_common(debug_info_t * id, int level, const void *buf, int len)
948{
949 unsigned long flags;
950 debug_entry_t *active;
951
952 if (!debug_active || !id->areas)
953 return NULL;
954 if (debug_critical) {
955 if (!spin_trylock_irqsave(&id->lock, flags))
956 return NULL;
957 } else
958 spin_lock_irqsave(&id->lock, flags);
959 active = get_active_entry(id);
960 memset(DEBUG_DATA(active), 0, id->buf_size);
961 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
962 debug_finish_entry(id, active, level, 0);
963 spin_unlock_irqrestore(&id->lock, flags);
964
965 return active;
966}
967
968/*
969 * debug_exception_common:
970 * - write debug entry with given size and switch to next debug area
971 */
972
973debug_entry_t
974*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
975{
976 unsigned long flags;
977 debug_entry_t *active;
978
979 if (!debug_active || !id->areas)
980 return NULL;
981 if (debug_critical) {
982 if (!spin_trylock_irqsave(&id->lock, flags))
983 return NULL;
984 } else
985 spin_lock_irqsave(&id->lock, flags);
986 active = get_active_entry(id);
987 memset(DEBUG_DATA(active), 0, id->buf_size);
988 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
989 debug_finish_entry(id, active, level, 1);
990 spin_unlock_irqrestore(&id->lock, flags);
991
992 return active;
993}
994
995/*
996 * counts arguments in format string for sprintf view
997 */
998
999static inline int
1000debug_count_numargs(char *string)
1001{
1002 int numargs=0;
1003
1004 while(*string) {
1005 if(*string++=='%')
1006 numargs++;
1007 }
1008 return(numargs);
1009}
1010
1011/*
1012 * debug_sprintf_event:
1013 */
1014
1015debug_entry_t*
1016debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1017{
1018 va_list ap;
1019 int numargs,idx;
1020 unsigned long flags;
1021 debug_sprintf_entry_t *curr_event;
1022 debug_entry_t *active;
1023
1024 if((!id) || (level > id->level))
1025 return NULL;
1026 if (!debug_active || !id->areas)
1027 return NULL;
1028 numargs=debug_count_numargs(string);
1029
1030 if (debug_critical) {
1031 if (!spin_trylock_irqsave(&id->lock, flags))
1032 return NULL;
1033 } else
1034 spin_lock_irqsave(&id->lock, flags);
1035 active = get_active_entry(id);
1036 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1037 va_start(ap,string);
1038 curr_event->string=string;
1039 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1040 curr_event->args[idx]=va_arg(ap,long);
1041 va_end(ap);
1042 debug_finish_entry(id, active, level, 0);
1043 spin_unlock_irqrestore(&id->lock, flags);
1044
1045 return active;
1046}
1047
1048/*
1049 * debug_sprintf_exception:
1050 */
1051
1052debug_entry_t*
1053debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1054{
1055 va_list ap;
1056 int numargs,idx;
1057 unsigned long flags;
1058 debug_sprintf_entry_t *curr_event;
1059 debug_entry_t *active;
1060
1061 if((!id) || (level > id->level))
1062 return NULL;
1063 if (!debug_active || !id->areas)
1064 return NULL;
1065
1066 numargs=debug_count_numargs(string);
1067
1068 if (debug_critical) {
1069 if (!spin_trylock_irqsave(&id->lock, flags))
1070 return NULL;
1071 } else
1072 spin_lock_irqsave(&id->lock, flags);
1073 active = get_active_entry(id);
1074 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1075 va_start(ap,string);
1076 curr_event->string=string;
1077 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1078 curr_event->args[idx]=va_arg(ap,long);
1079 va_end(ap);
1080 debug_finish_entry(id, active, level, 1);
1081 spin_unlock_irqrestore(&id->lock, flags);
1082
1083 return active;
1084}
1085
1086/*
1087 * debug_init:
1088 * - is called exactly once to initialize the debug feature
1089 */
1090
1091static int
1092__init debug_init(void)
1093{
1094 int rc = 0;
1095
1096 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1097 mutex_lock(&debug_mutex);
1098 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1099 initialized = 1;
1100 mutex_unlock(&debug_mutex);
1101
1102 return rc;
1103}
1104
1105/*
1106 * debug_register_view:
1107 */
1108
1109int
1110debug_register_view(debug_info_t * id, struct debug_view *view)
1111{
1112 int rc = 0;
1113 int i;
1114 unsigned long flags;
1115 umode_t mode;
1116 struct dentry *pde;
1117
1118 if (!id)
1119 goto out;
1120 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1121 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1122 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1123 if (!view->input_proc)
1124 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1125 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1126 id , &debug_file_ops);
1127 if (!pde){
1128 pr_err("Registering view %s/%s failed due to out of "
1129 "memory\n", id->name,view->name);
1130 rc = -1;
1131 goto out;
1132 }
1133 spin_lock_irqsave(&id->lock, flags);
1134 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1135 if (!id->views[i])
1136 break;
1137 }
1138 if (i == DEBUG_MAX_VIEWS) {
1139 pr_err("Registering view %s/%s would exceed the maximum "
1140 "number of views %i\n", id->name, view->name, i);
1141 debugfs_remove(pde);
1142 rc = -1;
1143 } else {
1144 id->views[i] = view;
1145 id->debugfs_entries[i] = pde;
1146 }
1147 spin_unlock_irqrestore(&id->lock, flags);
1148out:
1149 return rc;
1150}
1151
1152/*
1153 * debug_unregister_view:
1154 */
1155
1156int
1157debug_unregister_view(debug_info_t * id, struct debug_view *view)
1158{
1159 int rc = 0;
1160 int i;
1161 unsigned long flags;
1162
1163 if (!id)
1164 goto out;
1165 spin_lock_irqsave(&id->lock, flags);
1166 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1167 if (id->views[i] == view)
1168 break;
1169 }
1170 if (i == DEBUG_MAX_VIEWS)
1171 rc = -1;
1172 else {
1173 debugfs_remove(id->debugfs_entries[i]);
1174 id->views[i] = NULL;
1175 }
1176 spin_unlock_irqrestore(&id->lock, flags);
1177out:
1178 return rc;
1179}
1180
1181static inline char *
1182debug_get_user_string(const char __user *user_buf, size_t user_len)
1183{
1184 char* buffer;
1185
1186 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1187 if (!buffer)
1188 return ERR_PTR(-ENOMEM);
1189 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1190 kfree(buffer);
1191 return ERR_PTR(-EFAULT);
1192 }
1193 /* got the string, now strip linefeed. */
1194 if (buffer[user_len - 1] == '\n')
1195 buffer[user_len - 1] = 0;
1196 else
1197 buffer[user_len] = 0;
1198 return buffer;
1199}
1200
1201static inline int
1202debug_get_uint(char *buf)
1203{
1204 int rc;
1205
1206 buf = skip_spaces(buf);
1207 rc = simple_strtoul(buf, &buf, 10);
1208 if(*buf){
1209 rc = -EINVAL;
1210 }
1211 return rc;
1212}
1213
1214/*
1215 * functions for debug-views
1216 ***********************************
1217*/
1218
1219/*
1220 * prints out actual debug level
1221 */
1222
1223static int
1224debug_prolog_pages_fn(debug_info_t * id,
1225 struct debug_view *view, char *out_buf)
1226{
1227 return sprintf(out_buf, "%i\n", id->pages_per_area);
1228}
1229
1230/*
1231 * reads new size (number of pages per debug area)
1232 */
1233
1234static int
1235debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1236 struct file *file, const char __user *user_buf,
1237 size_t user_len, loff_t * offset)
1238{
1239 char *str;
1240 int rc,new_pages;
1241
1242 if (user_len > 0x10000)
1243 user_len = 0x10000;
1244 if (*offset != 0){
1245 rc = -EPIPE;
1246 goto out;
1247 }
1248 str = debug_get_user_string(user_buf,user_len);
1249 if(IS_ERR(str)){
1250 rc = PTR_ERR(str);
1251 goto out;
1252 }
1253 new_pages = debug_get_uint(str);
1254 if(new_pages < 0){
1255 rc = -EINVAL;
1256 goto free_str;
1257 }
1258 rc = debug_set_size(id,id->nr_areas, new_pages);
1259 if(rc != 0){
1260 rc = -EINVAL;
1261 goto free_str;
1262 }
1263 rc = user_len;
1264free_str:
1265 kfree(str);
1266out:
1267 *offset += user_len;
1268 return rc; /* number of input characters */
1269}
1270
1271/*
1272 * prints out actual debug level
1273 */
1274
1275static int
1276debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1277{
1278 int rc = 0;
1279
1280 if(id->level == DEBUG_OFF_LEVEL) {
1281 rc = sprintf(out_buf,"-\n");
1282 }
1283 else {
1284 rc = sprintf(out_buf, "%i\n", id->level);
1285 }
1286 return rc;
1287}
1288
1289/*
1290 * reads new debug level
1291 */
1292
1293static int
1294debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1295 struct file *file, const char __user *user_buf,
1296 size_t user_len, loff_t * offset)
1297{
1298 char *str;
1299 int rc,new_level;
1300
1301 if (user_len > 0x10000)
1302 user_len = 0x10000;
1303 if (*offset != 0){
1304 rc = -EPIPE;
1305 goto out;
1306 }
1307 str = debug_get_user_string(user_buf,user_len);
1308 if(IS_ERR(str)){
1309 rc = PTR_ERR(str);
1310 goto out;
1311 }
1312 if(str[0] == '-'){
1313 debug_set_level(id, DEBUG_OFF_LEVEL);
1314 rc = user_len;
1315 goto free_str;
1316 } else {
1317 new_level = debug_get_uint(str);
1318 }
1319 if(new_level < 0) {
1320 pr_warning("%s is not a valid level for a debug "
1321 "feature\n", str);
1322 rc = -EINVAL;
1323 } else {
1324 debug_set_level(id, new_level);
1325 rc = user_len;
1326 }
1327free_str:
1328 kfree(str);
1329out:
1330 *offset += user_len;
1331 return rc; /* number of input characters */
1332}
1333
1334
1335/*
1336 * flushes debug areas
1337 */
1338
1339static void debug_flush(debug_info_t* id, int area)
1340{
1341 unsigned long flags;
1342 int i,j;
1343
1344 if(!id || !id->areas)
1345 return;
1346 spin_lock_irqsave(&id->lock,flags);
1347 if(area == DEBUG_FLUSH_ALL){
1348 id->active_area = 0;
1349 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1350 for (i = 0; i < id->nr_areas; i++) {
1351 id->active_pages[i] = 0;
1352 for(j = 0; j < id->pages_per_area; j++) {
1353 memset(id->areas[i][j], 0, PAGE_SIZE);
1354 }
1355 }
1356 } else if(area >= 0 && area < id->nr_areas) {
1357 id->active_entries[area] = 0;
1358 id->active_pages[area] = 0;
1359 for(i = 0; i < id->pages_per_area; i++) {
1360 memset(id->areas[area][i],0,PAGE_SIZE);
1361 }
1362 }
1363 spin_unlock_irqrestore(&id->lock,flags);
1364}
1365
1366/*
1367 * view function: flushes debug areas
1368 */
1369
1370static int
1371debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1372 struct file *file, const char __user *user_buf,
1373 size_t user_len, loff_t * offset)
1374{
1375 char input_buf[1];
1376 int rc = user_len;
1377
1378 if (user_len > 0x10000)
1379 user_len = 0x10000;
1380 if (*offset != 0){
1381 rc = -EPIPE;
1382 goto out;
1383 }
1384 if (copy_from_user(input_buf, user_buf, 1)){
1385 rc = -EFAULT;
1386 goto out;
1387 }
1388 if(input_buf[0] == '-') {
1389 debug_flush(id, DEBUG_FLUSH_ALL);
1390 goto out;
1391 }
1392 if (isdigit(input_buf[0])) {
1393 int area = ((int) input_buf[0] - (int) '0');
1394 debug_flush(id, area);
1395 goto out;
1396 }
1397
1398 pr_info("Flushing debug data failed because %c is not a valid "
1399 "area\n", input_buf[0]);
1400
1401out:
1402 *offset += user_len;
1403 return rc; /* number of input characters */
1404}
1405
1406/*
1407 * prints debug header in raw format
1408 */
1409
1410static int
1411debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1412 int area, debug_entry_t * entry, char *out_buf)
1413{
1414 int rc;
1415
1416 rc = sizeof(debug_entry_t);
1417 memcpy(out_buf,entry,sizeof(debug_entry_t));
1418 return rc;
1419}
1420
1421/*
1422 * prints debug data in raw format
1423 */
1424
1425static int
1426debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1427 char *out_buf, const char *in_buf)
1428{
1429 int rc;
1430
1431 rc = id->buf_size;
1432 memcpy(out_buf, in_buf, id->buf_size);
1433 return rc;
1434}
1435
1436/*
1437 * prints debug data in hex/ascii format
1438 */
1439
1440static int
1441debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1442 char *out_buf, const char *in_buf)
1443{
1444 int i, rc = 0;
1445
1446 for (i = 0; i < id->buf_size; i++) {
1447 rc += sprintf(out_buf + rc, "%02x ",
1448 ((unsigned char *) in_buf)[i]);
1449 }
1450 rc += sprintf(out_buf + rc, "| ");
1451 for (i = 0; i < id->buf_size; i++) {
1452 unsigned char c = in_buf[i];
1453 if (isascii(c) && isprint(c))
1454 rc += sprintf(out_buf + rc, "%c", c);
1455 else
1456 rc += sprintf(out_buf + rc, ".");
1457 }
1458 rc += sprintf(out_buf + rc, "\n");
1459 return rc;
1460}
1461
1462/*
1463 * prints header for debug entry
1464 */
1465
1466int
1467debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1468 int area, debug_entry_t * entry, char *out_buf)
1469{
1470 struct timespec time_spec;
1471 char *except_str;
1472 unsigned long caller;
1473 int rc = 0;
1474 unsigned int level;
1475
1476 level = entry->id.fields.level;
1477 stck_to_timespec(entry->id.stck, &time_spec);
1478
1479 if (entry->id.fields.exception)
1480 except_str = "*";
1481 else
1482 except_str = "-";
1483 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1484 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1485 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1486 except_str, entry->id.fields.cpuid, (void *) caller);
1487 return rc;
1488}
1489
1490/*
1491 * prints debug data sprintf-formated:
1492 * debug_sprinf_event/exception calls must be used together with this view
1493 */
1494
1495#define DEBUG_SPRINTF_MAX_ARGS 10
1496
1497static int
1498debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1499 char *out_buf, debug_sprintf_entry_t *curr_event)
1500{
1501 int num_longs, num_used_args = 0,i, rc = 0;
1502 int index[DEBUG_SPRINTF_MAX_ARGS];
1503
1504 /* count of longs fit into one entry */
1505 num_longs = id->buf_size / sizeof(long);
1506
1507 if(num_longs < 1)
1508 goto out; /* bufsize of entry too small */
1509 if(num_longs == 1) {
1510 /* no args, we use only the string */
1511 strcpy(out_buf, curr_event->string);
1512 rc = strlen(curr_event->string);
1513 goto out;
1514 }
1515
1516 /* number of arguments used for sprintf (without the format string) */
1517 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1518
1519 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1520
1521 for(i = 0; i < num_used_args; i++)
1522 index[i] = i;
1523
1524 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1525 curr_event->args[index[1]], curr_event->args[index[2]],
1526 curr_event->args[index[3]], curr_event->args[index[4]],
1527 curr_event->args[index[5]], curr_event->args[index[6]],
1528 curr_event->args[index[7]], curr_event->args[index[8]],
1529 curr_event->args[index[9]]);
1530
1531out:
1532
1533 return rc;
1534}
1535
1536/*
1537 * clean up module
1538 */
1539static void __exit debug_exit(void)
1540{
1541 debugfs_remove(debug_debugfs_root_entry);
1542 unregister_sysctl_table(s390dbf_sysctl_header);
1543 return;
1544}
1545
1546/*
1547 * module definitions
1548 */
1549postcore_initcall(debug_init);
1550module_exit(debug_exit);
1551MODULE_LICENSE("GPL");
1552
1553EXPORT_SYMBOL(debug_register);
1554EXPORT_SYMBOL(debug_unregister);
1555EXPORT_SYMBOL(debug_set_level);
1556EXPORT_SYMBOL(debug_stop_all);
1557EXPORT_SYMBOL(debug_register_view);
1558EXPORT_SYMBOL(debug_unregister_view);
1559EXPORT_SYMBOL(debug_event_common);
1560EXPORT_SYMBOL(debug_exception_common);
1561EXPORT_SYMBOL(debug_hex_ascii_view);
1562EXPORT_SYMBOL(debug_raw_view);
1563EXPORT_SYMBOL(debug_dflt_header_fn);
1564EXPORT_SYMBOL(debug_sprintf_view);
1565EXPORT_SYMBOL(debug_sprintf_exception);
1566EXPORT_SYMBOL(debug_sprintf_event);