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