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