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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2020
6 *
7 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
8 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
9 *
10 * Bugreports to: <Linux390@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "s390dbf"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/ctype.h>
21#include <linux/string.h>
22#include <linux/sysctl.h>
23#include <linux/uaccess.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/minmax.h>
28#include <linux/debugfs.h>
29
30#include <asm/debug.h>
31
32#define DEBUG_PROLOG_ENTRY -1
33
34#define ALL_AREAS 0 /* copy all debug areas */
35#define NO_AREAS 1 /* copy no debug areas */
36
37/* typedefs */
38
39typedef struct file_private_info {
40 loff_t offset; /* offset of last read in file */
41 int act_area; /* number of last formated area */
42 int act_page; /* act page in given area */
43 int act_entry; /* last formated entry (offset */
44 /* relative to beginning of last */
45 /* formated page) */
46 size_t act_entry_offset; /* up to this offset we copied */
47 /* in last read the last formated */
48 /* entry to userland */
49 char temp_buf[2048]; /* buffer for output */
50 debug_info_t *debug_info_org; /* original debug information */
51 debug_info_t *debug_info_snap; /* snapshot of debug information */
52 struct debug_view *view; /* used view of debug info */
53} file_private_info_t;
54
55typedef struct {
56 char *string;
57 /*
58 * This assumes that all args are converted into longs
59 * on L/390 this is the case for all types of parameter
60 * except of floats, and long long (32 bit)
61 *
62 */
63 long args[0];
64} debug_sprintf_entry_t;
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_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
95 char *out_buf, debug_sprintf_entry_t *curr_event);
96static void debug_areas_swap(debug_info_t *a, debug_info_t *b);
97static void debug_events_append(debug_info_t *dest, debug_info_t *src);
98
99/* globals */
100
101struct debug_view debug_hex_ascii_view = {
102 "hex_ascii",
103 NULL,
104 &debug_dflt_header_fn,
105 &debug_hex_ascii_format_fn,
106 NULL,
107 NULL
108};
109EXPORT_SYMBOL(debug_hex_ascii_view);
110
111static struct debug_view debug_level_view = {
112 "level",
113 &debug_prolog_level_fn,
114 NULL,
115 NULL,
116 &debug_input_level_fn,
117 NULL
118};
119
120static struct debug_view debug_pages_view = {
121 "pages",
122 &debug_prolog_pages_fn,
123 NULL,
124 NULL,
125 &debug_input_pages_fn,
126 NULL
127};
128
129static struct debug_view debug_flush_view = {
130 "flush",
131 NULL,
132 NULL,
133 NULL,
134 &debug_input_flush_fn,
135 NULL
136};
137
138struct debug_view debug_sprintf_view = {
139 "sprintf",
140 NULL,
141 &debug_dflt_header_fn,
142 (debug_format_proc_t *)&debug_sprintf_format_fn,
143 NULL,
144 NULL
145};
146EXPORT_SYMBOL(debug_sprintf_view);
147
148/* used by dump analysis tools to determine version of debug feature */
149static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
150
151/* static globals */
152
153static debug_info_t *debug_area_first;
154static debug_info_t *debug_area_last;
155static DEFINE_MUTEX(debug_mutex);
156
157static int initialized;
158static int debug_critical;
159
160static const struct file_operations debug_file_ops = {
161 .owner = THIS_MODULE,
162 .read = debug_output,
163 .write = debug_input,
164 .open = debug_open,
165 .release = debug_close,
166 .llseek = no_llseek,
167};
168
169static struct dentry *debug_debugfs_root_entry;
170
171/* functions */
172
173/*
174 * debug_areas_alloc
175 * - Debug areas are implemented as a threedimensonal array:
176 * areas[areanumber][pagenumber][pageoffset]
177 */
178
179static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
180{
181 debug_entry_t ***areas;
182 int i, j;
183
184 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL);
185 if (!areas)
186 goto fail_malloc_areas;
187 for (i = 0; i < nr_areas; i++) {
188 /* GFP_NOWARN to avoid user triggerable WARN, we handle fails */
189 areas[i] = kmalloc_array(pages_per_area,
190 sizeof(debug_entry_t *),
191 GFP_KERNEL | __GFP_NOWARN);
192 if (!areas[i])
193 goto fail_malloc_areas2;
194 for (j = 0; j < pages_per_area; j++) {
195 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
196 if (!areas[i][j]) {
197 for (j--; j >= 0 ; j--)
198 kfree(areas[i][j]);
199 kfree(areas[i]);
200 goto fail_malloc_areas2;
201 }
202 }
203 }
204 return areas;
205
206fail_malloc_areas2:
207 for (i--; i >= 0; i--) {
208 for (j = 0; j < pages_per_area; j++)
209 kfree(areas[i][j]);
210 kfree(areas[i]);
211 }
212 kfree(areas);
213fail_malloc_areas:
214 return NULL;
215}
216
217/*
218 * debug_info_alloc
219 * - alloc new debug-info
220 */
221static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
222 int nr_areas, int buf_size, int level,
223 int mode)
224{
225 debug_info_t *rc;
226
227 /* alloc everything */
228 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
229 if (!rc)
230 goto fail_malloc_rc;
231 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
232 if (!rc->active_entries)
233 goto fail_malloc_active_entries;
234 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
235 if (!rc->active_pages)
236 goto fail_malloc_active_pages;
237 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
238 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
239 if (!rc->areas)
240 goto fail_malloc_areas;
241 } else {
242 rc->areas = NULL;
243 }
244
245 /* initialize members */
246 spin_lock_init(&rc->lock);
247 rc->pages_per_area = pages_per_area;
248 rc->nr_areas = nr_areas;
249 rc->active_area = 0;
250 rc->level = level;
251 rc->buf_size = buf_size;
252 rc->entry_size = sizeof(debug_entry_t) + buf_size;
253 strlcpy(rc->name, name, sizeof(rc->name));
254 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
255 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
256 refcount_set(&(rc->ref_count), 0);
257
258 return rc;
259
260fail_malloc_areas:
261 kfree(rc->active_pages);
262fail_malloc_active_pages:
263 kfree(rc->active_entries);
264fail_malloc_active_entries:
265 kfree(rc);
266fail_malloc_rc:
267 return NULL;
268}
269
270/*
271 * debug_areas_free
272 * - free all debug areas
273 */
274static void debug_areas_free(debug_info_t *db_info)
275{
276 int i, j;
277
278 if (!db_info->areas)
279 return;
280 for (i = 0; i < db_info->nr_areas; i++) {
281 for (j = 0; j < db_info->pages_per_area; j++)
282 kfree(db_info->areas[i][j]);
283 kfree(db_info->areas[i]);
284 }
285 kfree(db_info->areas);
286 db_info->areas = NULL;
287}
288
289/*
290 * debug_info_free
291 * - free memory debug-info
292 */
293static void debug_info_free(debug_info_t *db_info)
294{
295 debug_areas_free(db_info);
296 kfree(db_info->active_entries);
297 kfree(db_info->active_pages);
298 kfree(db_info);
299}
300
301/*
302 * debug_info_create
303 * - create new debug-info
304 */
305
306static debug_info_t *debug_info_create(const char *name, int pages_per_area,
307 int nr_areas, int buf_size, umode_t mode)
308{
309 debug_info_t *rc;
310
311 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
312 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
313 if (!rc)
314 goto out;
315
316 rc->mode = mode & ~S_IFMT;
317 refcount_set(&rc->ref_count, 1);
318out:
319 return rc;
320}
321
322/*
323 * debug_info_copy
324 * - copy debug-info
325 */
326static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
327{
328 unsigned long flags;
329 debug_info_t *rc;
330 int i, j;
331
332 /* get a consistent copy of the debug areas */
333 do {
334 rc = debug_info_alloc(in->name, in->pages_per_area,
335 in->nr_areas, in->buf_size, in->level, mode);
336 spin_lock_irqsave(&in->lock, flags);
337 if (!rc)
338 goto out;
339 /* has something changed in the meantime ? */
340 if ((rc->pages_per_area == in->pages_per_area) &&
341 (rc->nr_areas == in->nr_areas)) {
342 break;
343 }
344 spin_unlock_irqrestore(&in->lock, flags);
345 debug_info_free(rc);
346 } while (1);
347
348 if (mode == NO_AREAS)
349 goto out;
350
351 for (i = 0; i < in->nr_areas; i++) {
352 for (j = 0; j < in->pages_per_area; j++)
353 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
354 }
355out:
356 spin_unlock_irqrestore(&in->lock, flags);
357 return rc;
358}
359
360/*
361 * debug_info_get
362 * - increments reference count for debug-info
363 */
364static void debug_info_get(debug_info_t *db_info)
365{
366 if (db_info)
367 refcount_inc(&db_info->ref_count);
368}
369
370/*
371 * debug_info_put:
372 * - decreases reference count for debug-info and frees it if necessary
373 */
374static void debug_info_put(debug_info_t *db_info)
375{
376 if (!db_info)
377 return;
378 if (refcount_dec_and_test(&db_info->ref_count))
379 debug_info_free(db_info);
380}
381
382/*
383 * debug_format_entry:
384 * - format one debug entry and return size of formated data
385 */
386static int debug_format_entry(file_private_info_t *p_info)
387{
388 debug_info_t *id_snap = p_info->debug_info_snap;
389 struct debug_view *view = p_info->view;
390 debug_entry_t *act_entry;
391 size_t len = 0;
392
393 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
394 /* print prolog */
395 if (view->prolog_proc)
396 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
397 goto out;
398 }
399 if (!id_snap->areas) /* this is true, if we have a prolog only view */
400 goto out; /* or if 'pages_per_area' is 0 */
401 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
402 [p_info->act_page] + p_info->act_entry);
403
404 if (act_entry->clock == 0LL)
405 goto out; /* empty entry */
406 if (view->header_proc)
407 len += view->header_proc(id_snap, view, p_info->act_area,
408 act_entry, p_info->temp_buf + len);
409 if (view->format_proc)
410 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
411 DEBUG_DATA(act_entry));
412out:
413 return len;
414}
415
416/*
417 * debug_next_entry:
418 * - goto next entry in p_info
419 */
420static inline int debug_next_entry(file_private_info_t *p_info)
421{
422 debug_info_t *id;
423
424 id = p_info->debug_info_snap;
425 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
426 p_info->act_entry = 0;
427 p_info->act_page = 0;
428 goto out;
429 }
430 if (!id->areas)
431 return 1;
432 p_info->act_entry += id->entry_size;
433 /* switch to next page, if we reached the end of the page */
434 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
435 /* next page */
436 p_info->act_entry = 0;
437 p_info->act_page += 1;
438 if ((p_info->act_page % id->pages_per_area) == 0) {
439 /* next area */
440 p_info->act_area++;
441 p_info->act_page = 0;
442 }
443 if (p_info->act_area >= id->nr_areas)
444 return 1;
445 }
446out:
447 return 0;
448}
449
450/*
451 * debug_output:
452 * - called for user read()
453 * - copies formated debug entries to the user buffer
454 */
455static ssize_t debug_output(struct file *file, /* file descriptor */
456 char __user *user_buf, /* user buffer */
457 size_t len, /* length of buffer */
458 loff_t *offset) /* offset in the file */
459{
460 size_t count = 0;
461 size_t entry_offset;
462 file_private_info_t *p_info;
463
464 p_info = (file_private_info_t *) file->private_data;
465 if (*offset != p_info->offset)
466 return -EPIPE;
467 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
468 return 0;
469 entry_offset = p_info->act_entry_offset;
470 while (count < len) {
471 int formatted_line_residue;
472 int formatted_line_size;
473 int user_buf_residue;
474 size_t copy_size;
475
476 formatted_line_size = debug_format_entry(p_info);
477 formatted_line_residue = formatted_line_size - entry_offset;
478 user_buf_residue = len-count;
479 copy_size = min(user_buf_residue, formatted_line_residue);
480 if (copy_size) {
481 if (copy_to_user(user_buf + count, p_info->temp_buf
482 + entry_offset, copy_size))
483 return -EFAULT;
484 count += copy_size;
485 entry_offset += copy_size;
486 }
487 if (copy_size == formatted_line_residue) {
488 entry_offset = 0;
489 if (debug_next_entry(p_info))
490 goto out;
491 }
492 }
493out:
494 p_info->offset = *offset + count;
495 p_info->act_entry_offset = entry_offset;
496 *offset = p_info->offset;
497 return count;
498}
499
500/*
501 * debug_input:
502 * - called for user write()
503 * - calls input function of view
504 */
505static ssize_t debug_input(struct file *file, const char __user *user_buf,
506 size_t length, loff_t *offset)
507{
508 file_private_info_t *p_info;
509 int rc = 0;
510
511 mutex_lock(&debug_mutex);
512 p_info = ((file_private_info_t *) file->private_data);
513 if (p_info->view->input_proc) {
514 rc = p_info->view->input_proc(p_info->debug_info_org,
515 p_info->view, file, user_buf,
516 length, offset);
517 } else {
518 rc = -EPERM;
519 }
520 mutex_unlock(&debug_mutex);
521 return rc; /* number of input characters */
522}
523
524/*
525 * debug_open:
526 * - called for user open()
527 * - copies formated output to private_data area of the file
528 * handle
529 */
530static int debug_open(struct inode *inode, struct file *file)
531{
532 debug_info_t *debug_info, *debug_info_snapshot;
533 file_private_info_t *p_info;
534 int i, rc = 0;
535
536 mutex_lock(&debug_mutex);
537 debug_info = file_inode(file)->i_private;
538 /* find debug view */
539 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
540 if (!debug_info->views[i])
541 continue;
542 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
543 goto found; /* found view ! */
544 }
545 /* no entry found */
546 rc = -EINVAL;
547 goto out;
548
549found:
550
551 /* Make snapshot of current debug areas to get it consistent. */
552 /* To copy all the areas is only needed, if we have a view which */
553 /* formats the debug areas. */
554
555 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
556 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
557 else
558 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
559
560 if (!debug_info_snapshot) {
561 rc = -ENOMEM;
562 goto out;
563 }
564 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
565 if (!p_info) {
566 debug_info_free(debug_info_snapshot);
567 rc = -ENOMEM;
568 goto out;
569 }
570 p_info->offset = 0;
571 p_info->debug_info_snap = debug_info_snapshot;
572 p_info->debug_info_org = debug_info;
573 p_info->view = debug_info->views[i];
574 p_info->act_area = 0;
575 p_info->act_page = 0;
576 p_info->act_entry = DEBUG_PROLOG_ENTRY;
577 p_info->act_entry_offset = 0;
578 file->private_data = p_info;
579 debug_info_get(debug_info);
580 nonseekable_open(inode, file);
581out:
582 mutex_unlock(&debug_mutex);
583 return rc;
584}
585
586/*
587 * debug_close:
588 * - called for user close()
589 * - deletes private_data area of the file handle
590 */
591static int debug_close(struct inode *inode, struct file *file)
592{
593 file_private_info_t *p_info;
594
595 p_info = (file_private_info_t *) file->private_data;
596 if (p_info->debug_info_snap)
597 debug_info_free(p_info->debug_info_snap);
598 debug_info_put(p_info->debug_info_org);
599 kfree(file->private_data);
600 return 0; /* success */
601}
602
603/* Create debugfs entries and add to internal list. */
604static void _debug_register(debug_info_t *id)
605{
606 /* create root directory */
607 id->debugfs_root_entry = debugfs_create_dir(id->name,
608 debug_debugfs_root_entry);
609
610 /* append new element to linked list */
611 if (!debug_area_first) {
612 /* first element in list */
613 debug_area_first = id;
614 id->prev = NULL;
615 } else {
616 /* append element to end of list */
617 debug_area_last->next = id;
618 id->prev = debug_area_last;
619 }
620 debug_area_last = id;
621 id->next = NULL;
622
623 debug_register_view(id, &debug_level_view);
624 debug_register_view(id, &debug_flush_view);
625 debug_register_view(id, &debug_pages_view);
626}
627
628/**
629 * debug_register_mode() - creates and initializes debug area.
630 *
631 * @name: Name of debug log (e.g. used for debugfs entry)
632 * @pages_per_area: Number of pages, which will be allocated per area
633 * @nr_areas: Number of debug areas
634 * @buf_size: Size of data area in each debug entry
635 * @mode: File mode for debugfs files. E.g. S_IRWXUGO
636 * @uid: User ID for debugfs files. Currently only 0 is supported.
637 * @gid: Group ID for debugfs files. Currently only 0 is supported.
638 *
639 * Return:
640 * - Handle for generated debug area
641 * - %NULL if register failed
642 *
643 * Allocates memory for a debug log.
644 * Must not be called within an interrupt handler.
645 */
646debug_info_t *debug_register_mode(const char *name, int pages_per_area,
647 int nr_areas, int buf_size, umode_t mode,
648 uid_t uid, gid_t gid)
649{
650 debug_info_t *rc = NULL;
651
652 /* Since debugfs currently does not support uid/gid other than root, */
653 /* we do not allow gid/uid != 0 until we get support for that. */
654 if ((uid != 0) || (gid != 0))
655 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
656 BUG_ON(!initialized);
657
658 /* create new debug_info */
659 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
660 if (rc) {
661 mutex_lock(&debug_mutex);
662 _debug_register(rc);
663 mutex_unlock(&debug_mutex);
664 } else {
665 pr_err("Registering debug feature %s failed\n", name);
666 }
667 return rc;
668}
669EXPORT_SYMBOL(debug_register_mode);
670
671/**
672 * debug_register() - creates and initializes debug area with default file mode.
673 *
674 * @name: Name of debug log (e.g. used for debugfs entry)
675 * @pages_per_area: Number of pages, which will be allocated per area
676 * @nr_areas: Number of debug areas
677 * @buf_size: Size of data area in each debug entry
678 *
679 * Return:
680 * - Handle for generated debug area
681 * - %NULL if register failed
682 *
683 * Allocates memory for a debug log.
684 * The debugfs file mode access permissions are read and write for user.
685 * Must not be called within an interrupt handler.
686 */
687debug_info_t *debug_register(const char *name, int pages_per_area,
688 int nr_areas, int buf_size)
689{
690 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
691 S_IRUSR | S_IWUSR, 0, 0);
692}
693EXPORT_SYMBOL(debug_register);
694
695/* Remove debugfs entries and remove from internal list. */
696static void _debug_unregister(debug_info_t *id)
697{
698 int i;
699
700 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
701 if (!id->views[i])
702 continue;
703 debugfs_remove(id->debugfs_entries[i]);
704 }
705 debugfs_remove(id->debugfs_root_entry);
706 if (id == debug_area_first)
707 debug_area_first = id->next;
708 if (id == debug_area_last)
709 debug_area_last = id->prev;
710 if (id->prev)
711 id->prev->next = id->next;
712 if (id->next)
713 id->next->prev = id->prev;
714}
715
716/**
717 * debug_unregister() - give back debug area.
718 *
719 * @id: handle for debug log
720 *
721 * Return:
722 * none
723 */
724void debug_unregister(debug_info_t *id)
725{
726 if (!id)
727 return;
728 mutex_lock(&debug_mutex);
729 _debug_unregister(id);
730 mutex_unlock(&debug_mutex);
731
732 debug_info_put(id);
733}
734EXPORT_SYMBOL(debug_unregister);
735
736/*
737 * debug_set_size:
738 * - set area size (number of pages) and number of areas
739 */
740static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
741{
742 debug_info_t *new_id;
743 unsigned long flags;
744
745 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
746 return -EINVAL;
747
748 new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
749 id->level, ALL_AREAS);
750 if (!new_id) {
751 pr_info("Allocating memory for %i pages failed\n",
752 pages_per_area);
753 return -ENOMEM;
754 }
755
756 spin_lock_irqsave(&id->lock, flags);
757 debug_events_append(new_id, id);
758 debug_areas_swap(new_id, id);
759 debug_info_free(new_id);
760 spin_unlock_irqrestore(&id->lock, flags);
761 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
762
763 return 0;
764}
765
766/**
767 * debug_set_level() - Sets new actual debug level if new_level is valid.
768 *
769 * @id: handle for debug log
770 * @new_level: new debug level
771 *
772 * Return:
773 * none
774 */
775void debug_set_level(debug_info_t *id, int new_level)
776{
777 unsigned long flags;
778
779 if (!id)
780 return;
781 spin_lock_irqsave(&id->lock, flags);
782 if (new_level == DEBUG_OFF_LEVEL) {
783 id->level = DEBUG_OFF_LEVEL;
784 pr_info("%s: switched off\n", id->name);
785 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
786 pr_info("%s: level %i is out of range (%i - %i)\n",
787 id->name, new_level, 0, DEBUG_MAX_LEVEL);
788 } else {
789 id->level = new_level;
790 }
791 spin_unlock_irqrestore(&id->lock, flags);
792}
793EXPORT_SYMBOL(debug_set_level);
794
795/*
796 * proceed_active_entry:
797 * - set active entry to next in the ring buffer
798 */
799static inline void proceed_active_entry(debug_info_t *id)
800{
801 if ((id->active_entries[id->active_area] += id->entry_size)
802 > (PAGE_SIZE - id->entry_size)) {
803 id->active_entries[id->active_area] = 0;
804 id->active_pages[id->active_area] =
805 (id->active_pages[id->active_area] + 1) %
806 id->pages_per_area;
807 }
808}
809
810/*
811 * proceed_active_area:
812 * - set active area to next in the ring buffer
813 */
814static inline void proceed_active_area(debug_info_t *id)
815{
816 id->active_area++;
817 id->active_area = id->active_area % id->nr_areas;
818}
819
820/*
821 * get_active_entry:
822 */
823static inline debug_entry_t *get_active_entry(debug_info_t *id)
824{
825 return (debug_entry_t *) (((char *) id->areas[id->active_area]
826 [id->active_pages[id->active_area]]) +
827 id->active_entries[id->active_area]);
828}
829
830/* Swap debug areas of a and b. */
831static void debug_areas_swap(debug_info_t *a, debug_info_t *b)
832{
833 swap(a->nr_areas, b->nr_areas);
834 swap(a->pages_per_area, b->pages_per_area);
835 swap(a->areas, b->areas);
836 swap(a->active_area, b->active_area);
837 swap(a->active_pages, b->active_pages);
838 swap(a->active_entries, b->active_entries);
839}
840
841/* Append all debug events in active area from source to destination log. */
842static void debug_events_append(debug_info_t *dest, debug_info_t *src)
843{
844 debug_entry_t *from, *to, *last;
845
846 if (!src->areas || !dest->areas)
847 return;
848
849 /* Loop over all entries in src, starting with oldest. */
850 from = get_active_entry(src);
851 last = from;
852 do {
853 if (from->clock != 0LL) {
854 to = get_active_entry(dest);
855 memset(to, 0, dest->entry_size);
856 memcpy(to, from, min(src->entry_size,
857 dest->entry_size));
858 proceed_active_entry(dest);
859 }
860
861 proceed_active_entry(src);
862 from = get_active_entry(src);
863 } while (from != last);
864}
865
866/*
867 * debug_finish_entry:
868 * - set timestamp, caller address, cpu number etc.
869 */
870
871static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
872 int level, int exception)
873{
874 unsigned long timestamp;
875 union tod_clock clk;
876
877 store_tod_clock_ext(&clk);
878 timestamp = clk.us;
879 timestamp -= TOD_UNIX_EPOCH >> 12;
880 active->clock = timestamp;
881 active->cpu = smp_processor_id();
882 active->caller = __builtin_return_address(0);
883 active->exception = exception;
884 active->level = level;
885 proceed_active_entry(id);
886 if (exception)
887 proceed_active_area(id);
888}
889
890static int debug_stoppable = 1;
891static int debug_active = 1;
892
893#define CTL_S390DBF_STOPPABLE 5678
894#define CTL_S390DBF_ACTIVE 5679
895
896/*
897 * proc handler for the running debug_active sysctl
898 * always allow read, allow write only if debug_stoppable is set or
899 * if debug_active is already off
900 */
901static int s390dbf_procactive(struct ctl_table *table, int write,
902 void *buffer, size_t *lenp, loff_t *ppos)
903{
904 if (!write || debug_stoppable || !debug_active)
905 return proc_dointvec(table, write, buffer, lenp, ppos);
906 else
907 return 0;
908}
909
910static struct ctl_table s390dbf_table[] = {
911 {
912 .procname = "debug_stoppable",
913 .data = &debug_stoppable,
914 .maxlen = sizeof(int),
915 .mode = S_IRUGO | S_IWUSR,
916 .proc_handler = proc_dointvec,
917 },
918 {
919 .procname = "debug_active",
920 .data = &debug_active,
921 .maxlen = sizeof(int),
922 .mode = S_IRUGO | S_IWUSR,
923 .proc_handler = s390dbf_procactive,
924 },
925 { }
926};
927
928static struct ctl_table s390dbf_dir_table[] = {
929 {
930 .procname = "s390dbf",
931 .maxlen = 0,
932 .mode = S_IRUGO | S_IXUGO,
933 .child = s390dbf_table,
934 },
935 { }
936};
937
938static struct ctl_table_header *s390dbf_sysctl_header;
939
940/**
941 * debug_stop_all() - stops the debug feature if stopping is allowed.
942 *
943 * Return:
944 * - none
945 *
946 * Currently used in case of a kernel oops.
947 */
948void debug_stop_all(void)
949{
950 if (debug_stoppable)
951 debug_active = 0;
952}
953EXPORT_SYMBOL(debug_stop_all);
954
955/**
956 * debug_set_critical() - event/exception functions try lock instead of spin.
957 *
958 * Return:
959 * - none
960 *
961 * Currently used in case of stopping all CPUs but the current one.
962 * Once in this state, functions to write a debug entry for an
963 * event or exception no longer spin on the debug area lock,
964 * but only try to get it and fail if they do not get the lock.
965 */
966void debug_set_critical(void)
967{
968 debug_critical = 1;
969}
970
971/*
972 * debug_event_common:
973 * - write debug entry with given size
974 */
975debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
976 int len)
977{
978 debug_entry_t *active;
979 unsigned long flags;
980
981 if (!debug_active || !id->areas)
982 return NULL;
983 if (debug_critical) {
984 if (!spin_trylock_irqsave(&id->lock, flags))
985 return NULL;
986 } else {
987 spin_lock_irqsave(&id->lock, flags);
988 }
989 do {
990 active = get_active_entry(id);
991 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
992 if (len < id->buf_size)
993 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
994 debug_finish_entry(id, active, level, 0);
995 len -= id->buf_size;
996 buf += id->buf_size;
997 } while (len > 0);
998
999 spin_unlock_irqrestore(&id->lock, flags);
1000 return active;
1001}
1002EXPORT_SYMBOL(debug_event_common);
1003
1004/*
1005 * debug_exception_common:
1006 * - write debug entry with given size and switch to next debug area
1007 */
1008debug_entry_t *debug_exception_common(debug_info_t *id, int level,
1009 const void *buf, int len)
1010{
1011 debug_entry_t *active;
1012 unsigned long flags;
1013
1014 if (!debug_active || !id->areas)
1015 return NULL;
1016 if (debug_critical) {
1017 if (!spin_trylock_irqsave(&id->lock, flags))
1018 return NULL;
1019 } else {
1020 spin_lock_irqsave(&id->lock, flags);
1021 }
1022 do {
1023 active = get_active_entry(id);
1024 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1025 if (len < id->buf_size)
1026 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1027 debug_finish_entry(id, active, level, len <= id->buf_size);
1028 len -= id->buf_size;
1029 buf += id->buf_size;
1030 } while (len > 0);
1031
1032 spin_unlock_irqrestore(&id->lock, flags);
1033 return active;
1034}
1035EXPORT_SYMBOL(debug_exception_common);
1036
1037/*
1038 * counts arguments in format string for sprintf view
1039 */
1040static inline int debug_count_numargs(char *string)
1041{
1042 int numargs = 0;
1043
1044 while (*string) {
1045 if (*string++ == '%')
1046 numargs++;
1047 }
1048 return numargs;
1049}
1050
1051/*
1052 * debug_sprintf_event:
1053 */
1054debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1055{
1056 debug_sprintf_entry_t *curr_event;
1057 debug_entry_t *active;
1058 unsigned long flags;
1059 int numargs, idx;
1060 va_list ap;
1061
1062 if (!debug_active || !id->areas)
1063 return NULL;
1064 numargs = debug_count_numargs(string);
1065
1066 if (debug_critical) {
1067 if (!spin_trylock_irqsave(&id->lock, flags))
1068 return NULL;
1069 } else {
1070 spin_lock_irqsave(&id->lock, flags);
1071 }
1072 active = get_active_entry(id);
1073 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1074 va_start(ap, string);
1075 curr_event->string = string;
1076 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1077 curr_event->args[idx] = va_arg(ap, long);
1078 va_end(ap);
1079 debug_finish_entry(id, active, level, 0);
1080 spin_unlock_irqrestore(&id->lock, flags);
1081
1082 return active;
1083}
1084EXPORT_SYMBOL(__debug_sprintf_event);
1085
1086/*
1087 * debug_sprintf_exception:
1088 */
1089debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1090{
1091 debug_sprintf_entry_t *curr_event;
1092 debug_entry_t *active;
1093 unsigned long flags;
1094 int numargs, idx;
1095 va_list ap;
1096
1097 if (!debug_active || !id->areas)
1098 return NULL;
1099
1100 numargs = debug_count_numargs(string);
1101
1102 if (debug_critical) {
1103 if (!spin_trylock_irqsave(&id->lock, flags))
1104 return NULL;
1105 } else {
1106 spin_lock_irqsave(&id->lock, flags);
1107 }
1108 active = get_active_entry(id);
1109 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1110 va_start(ap, string);
1111 curr_event->string = string;
1112 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1113 curr_event->args[idx] = va_arg(ap, long);
1114 va_end(ap);
1115 debug_finish_entry(id, active, level, 1);
1116 spin_unlock_irqrestore(&id->lock, flags);
1117
1118 return active;
1119}
1120EXPORT_SYMBOL(__debug_sprintf_exception);
1121
1122/**
1123 * debug_register_view() - registers new debug view and creates debugfs
1124 * dir entry
1125 *
1126 * @id: handle for debug log
1127 * @view: pointer to debug view struct
1128 *
1129 * Return:
1130 * - 0 : ok
1131 * - < 0: Error
1132 */
1133int debug_register_view(debug_info_t *id, struct debug_view *view)
1134{
1135 unsigned long flags;
1136 struct dentry *pde;
1137 umode_t mode;
1138 int rc = 0;
1139 int i;
1140
1141 if (!id)
1142 goto out;
1143 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1144 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1145 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1146 if (!view->input_proc)
1147 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1148 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1149 id, &debug_file_ops);
1150 spin_lock_irqsave(&id->lock, flags);
1151 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1152 if (!id->views[i])
1153 break;
1154 }
1155 if (i == DEBUG_MAX_VIEWS) {
1156 pr_err("Registering view %s/%s would exceed the maximum "
1157 "number of views %i\n", id->name, view->name, i);
1158 rc = -1;
1159 } else {
1160 id->views[i] = view;
1161 id->debugfs_entries[i] = pde;
1162 }
1163 spin_unlock_irqrestore(&id->lock, flags);
1164 if (rc)
1165 debugfs_remove(pde);
1166out:
1167 return rc;
1168}
1169EXPORT_SYMBOL(debug_register_view);
1170
1171/**
1172 * debug_unregister_view() - unregisters debug view and removes debugfs
1173 * dir entry
1174 *
1175 * @id: handle for debug log
1176 * @view: pointer to debug view struct
1177 *
1178 * Return:
1179 * - 0 : ok
1180 * - < 0: Error
1181 */
1182int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1183{
1184 struct dentry *dentry = NULL;
1185 unsigned long flags;
1186 int i, rc = 0;
1187
1188 if (!id)
1189 goto out;
1190 spin_lock_irqsave(&id->lock, flags);
1191 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1192 if (id->views[i] == view)
1193 break;
1194 }
1195 if (i == DEBUG_MAX_VIEWS) {
1196 rc = -1;
1197 } else {
1198 dentry = id->debugfs_entries[i];
1199 id->views[i] = NULL;
1200 id->debugfs_entries[i] = NULL;
1201 }
1202 spin_unlock_irqrestore(&id->lock, flags);
1203 debugfs_remove(dentry);
1204out:
1205 return rc;
1206}
1207EXPORT_SYMBOL(debug_unregister_view);
1208
1209static inline char *debug_get_user_string(const char __user *user_buf,
1210 size_t user_len)
1211{
1212 char *buffer;
1213
1214 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1215 if (!buffer)
1216 return ERR_PTR(-ENOMEM);
1217 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1218 kfree(buffer);
1219 return ERR_PTR(-EFAULT);
1220 }
1221 /* got the string, now strip linefeed. */
1222 if (buffer[user_len - 1] == '\n')
1223 buffer[user_len - 1] = 0;
1224 else
1225 buffer[user_len] = 0;
1226 return buffer;
1227}
1228
1229static inline int debug_get_uint(char *buf)
1230{
1231 int rc;
1232
1233 buf = skip_spaces(buf);
1234 rc = simple_strtoul(buf, &buf, 10);
1235 if (*buf)
1236 rc = -EINVAL;
1237 return rc;
1238}
1239
1240/*
1241 * functions for debug-views
1242 ***********************************
1243*/
1244
1245/*
1246 * prints out actual debug level
1247 */
1248
1249static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1250 char *out_buf)
1251{
1252 return sprintf(out_buf, "%i\n", id->pages_per_area);
1253}
1254
1255/*
1256 * reads new size (number of pages per debug area)
1257 */
1258
1259static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1260 struct file *file, const char __user *user_buf,
1261 size_t user_len, loff_t *offset)
1262{
1263 int rc, new_pages;
1264 char *str;
1265
1266 if (user_len > 0x10000)
1267 user_len = 0x10000;
1268 if (*offset != 0) {
1269 rc = -EPIPE;
1270 goto out;
1271 }
1272 str = debug_get_user_string(user_buf, user_len);
1273 if (IS_ERR(str)) {
1274 rc = PTR_ERR(str);
1275 goto out;
1276 }
1277 new_pages = debug_get_uint(str);
1278 if (new_pages < 0) {
1279 rc = -EINVAL;
1280 goto free_str;
1281 }
1282 rc = debug_set_size(id, id->nr_areas, new_pages);
1283 if (rc != 0) {
1284 rc = -EINVAL;
1285 goto free_str;
1286 }
1287 rc = user_len;
1288free_str:
1289 kfree(str);
1290out:
1291 *offset += user_len;
1292 return rc; /* number of input characters */
1293}
1294
1295/*
1296 * prints out actual debug level
1297 */
1298static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1299 char *out_buf)
1300{
1301 int rc = 0;
1302
1303 if (id->level == DEBUG_OFF_LEVEL)
1304 rc = sprintf(out_buf, "-\n");
1305 else
1306 rc = sprintf(out_buf, "%i\n", id->level);
1307 return rc;
1308}
1309
1310/*
1311 * reads new debug level
1312 */
1313static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1314 struct file *file, const char __user *user_buf,
1315 size_t user_len, loff_t *offset)
1316{
1317 int rc, new_level;
1318 char *str;
1319
1320 if (user_len > 0x10000)
1321 user_len = 0x10000;
1322 if (*offset != 0) {
1323 rc = -EPIPE;
1324 goto out;
1325 }
1326 str = debug_get_user_string(user_buf, user_len);
1327 if (IS_ERR(str)) {
1328 rc = PTR_ERR(str);
1329 goto out;
1330 }
1331 if (str[0] == '-') {
1332 debug_set_level(id, DEBUG_OFF_LEVEL);
1333 rc = user_len;
1334 goto free_str;
1335 } else {
1336 new_level = debug_get_uint(str);
1337 }
1338 if (new_level < 0) {
1339 pr_warn("%s is not a valid level for a debug feature\n", str);
1340 rc = -EINVAL;
1341 } else {
1342 debug_set_level(id, new_level);
1343 rc = user_len;
1344 }
1345free_str:
1346 kfree(str);
1347out:
1348 *offset += user_len;
1349 return rc; /* number of input characters */
1350}
1351
1352/*
1353 * flushes debug areas
1354 */
1355static void debug_flush(debug_info_t *id, int area)
1356{
1357 unsigned long flags;
1358 int i, j;
1359
1360 if (!id || !id->areas)
1361 return;
1362 spin_lock_irqsave(&id->lock, flags);
1363 if (area == DEBUG_FLUSH_ALL) {
1364 id->active_area = 0;
1365 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1366 for (i = 0; i < id->nr_areas; i++) {
1367 id->active_pages[i] = 0;
1368 for (j = 0; j < id->pages_per_area; j++)
1369 memset(id->areas[i][j], 0, PAGE_SIZE);
1370 }
1371 } else if (area >= 0 && area < id->nr_areas) {
1372 id->active_entries[area] = 0;
1373 id->active_pages[area] = 0;
1374 for (i = 0; i < id->pages_per_area; i++)
1375 memset(id->areas[area][i], 0, PAGE_SIZE);
1376 }
1377 spin_unlock_irqrestore(&id->lock, flags);
1378}
1379
1380/*
1381 * view function: flushes debug areas
1382 */
1383static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1384 struct file *file, const char __user *user_buf,
1385 size_t user_len, loff_t *offset)
1386{
1387 char input_buf[1];
1388 int rc = user_len;
1389
1390 if (user_len > 0x10000)
1391 user_len = 0x10000;
1392 if (*offset != 0) {
1393 rc = -EPIPE;
1394 goto out;
1395 }
1396 if (copy_from_user(input_buf, user_buf, 1)) {
1397 rc = -EFAULT;
1398 goto out;
1399 }
1400 if (input_buf[0] == '-') {
1401 debug_flush(id, DEBUG_FLUSH_ALL);
1402 goto out;
1403 }
1404 if (isdigit(input_buf[0])) {
1405 int area = ((int) input_buf[0] - (int) '0');
1406
1407 debug_flush(id, area);
1408 goto out;
1409 }
1410
1411 pr_info("Flushing debug data failed because %c is not a valid "
1412 "area\n", input_buf[0]);
1413
1414out:
1415 *offset += user_len;
1416 return rc; /* number of input characters */
1417}
1418
1419/*
1420 * prints debug data in hex/ascii format
1421 */
1422static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1423 char *out_buf, const char *in_buf)
1424{
1425 int i, rc = 0;
1426
1427 for (i = 0; i < id->buf_size; i++)
1428 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1429 rc += sprintf(out_buf + rc, "| ");
1430 for (i = 0; i < id->buf_size; i++) {
1431 unsigned char c = in_buf[i];
1432
1433 if (isascii(c) && isprint(c))
1434 rc += sprintf(out_buf + rc, "%c", c);
1435 else
1436 rc += sprintf(out_buf + rc, ".");
1437 }
1438 rc += sprintf(out_buf + rc, "\n");
1439 return rc;
1440}
1441
1442/*
1443 * prints header for debug entry
1444 */
1445int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1446 int area, debug_entry_t *entry, char *out_buf)
1447{
1448 unsigned long sec, usec;
1449 unsigned long caller;
1450 unsigned int level;
1451 char *except_str;
1452 int rc = 0;
1453
1454 level = entry->level;
1455 sec = entry->clock;
1456 usec = do_div(sec, USEC_PER_SEC);
1457
1458 if (entry->exception)
1459 except_str = "*";
1460 else
1461 except_str = "-";
1462 caller = (unsigned long) entry->caller;
1463 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %04u %px ",
1464 area, sec, usec, level, except_str,
1465 entry->cpu, (void *)caller);
1466 return rc;
1467}
1468EXPORT_SYMBOL(debug_dflt_header_fn);
1469
1470/*
1471 * prints debug data sprintf-formated:
1472 * debug_sprinf_event/exception calls must be used together with this view
1473 */
1474
1475#define DEBUG_SPRINTF_MAX_ARGS 10
1476
1477static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1478 char *out_buf, debug_sprintf_entry_t *curr_event)
1479{
1480 int num_longs, num_used_args = 0, i, rc = 0;
1481 int index[DEBUG_SPRINTF_MAX_ARGS];
1482
1483 /* count of longs fit into one entry */
1484 num_longs = id->buf_size / sizeof(long);
1485
1486 if (num_longs < 1)
1487 goto out; /* bufsize of entry too small */
1488 if (num_longs == 1) {
1489 /* no args, we use only the string */
1490 strcpy(out_buf, curr_event->string);
1491 rc = strlen(curr_event->string);
1492 goto out;
1493 }
1494
1495 /* number of arguments used for sprintf (without the format string) */
1496 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1497
1498 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1499
1500 for (i = 0; i < num_used_args; i++)
1501 index[i] = i;
1502
1503 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1504 curr_event->args[index[1]], curr_event->args[index[2]],
1505 curr_event->args[index[3]], curr_event->args[index[4]],
1506 curr_event->args[index[5]], curr_event->args[index[6]],
1507 curr_event->args[index[7]], curr_event->args[index[8]],
1508 curr_event->args[index[9]]);
1509out:
1510 return rc;
1511}
1512
1513/*
1514 * debug_init:
1515 * - is called exactly once to initialize the debug feature
1516 */
1517static int __init debug_init(void)
1518{
1519 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1520 mutex_lock(&debug_mutex);
1521 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1522 initialized = 1;
1523 mutex_unlock(&debug_mutex);
1524 return 0;
1525}
1526postcore_initcall(debug_init);
1/*
2 * arch/s390/kernel/debug.c
3 * S/390 debug facility
4 *
5 * Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH,
6 * IBM Corporation
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, mode_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;
170
171static const struct file_operations debug_file_ops = {
172 .owner = THIS_MODULE,
173 .read = debug_output,
174 .write = debug_input,
175 .open = debug_open,
176 .release = debug_close,
177 .llseek = no_llseek,
178};
179
180static struct dentry *debug_debugfs_root_entry;
181
182/* functions */
183
184/*
185 * debug_areas_alloc
186 * - Debug areas are implemented as a threedimensonal array:
187 * areas[areanumber][pagenumber][pageoffset]
188 */
189
190static debug_entry_t***
191debug_areas_alloc(int pages_per_area, int nr_areas)
192{
193 debug_entry_t*** areas;
194 int i,j;
195
196 areas = kmalloc(nr_areas *
197 sizeof(debug_entry_t**),
198 GFP_KERNEL);
199 if (!areas)
200 goto fail_malloc_areas;
201 for (i = 0; i < nr_areas; i++) {
202 areas[i] = kmalloc(pages_per_area *
203 sizeof(debug_entry_t*),GFP_KERNEL);
204 if (!areas[i]) {
205 goto fail_malloc_areas2;
206 }
207 for(j = 0; j < pages_per_area; j++) {
208 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
209 if(!areas[i][j]) {
210 for(j--; j >=0 ; j--) {
211 kfree(areas[i][j]);
212 }
213 kfree(areas[i]);
214 goto fail_malloc_areas2;
215 }
216 }
217 }
218 return areas;
219
220fail_malloc_areas2:
221 for(i--; i >= 0; i--){
222 for(j=0; j < pages_per_area;j++){
223 kfree(areas[i][j]);
224 }
225 kfree(areas[i]);
226 }
227 kfree(areas);
228fail_malloc_areas:
229 return NULL;
230
231}
232
233
234/*
235 * debug_info_alloc
236 * - alloc new debug-info
237 */
238
239static debug_info_t*
240debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
241 int buf_size, int level, int mode)
242{
243 debug_info_t* rc;
244
245 /* alloc everything */
246
247 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
248 if(!rc)
249 goto fail_malloc_rc;
250 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
251 if(!rc->active_entries)
252 goto fail_malloc_active_entries;
253 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254 if(!rc->active_pages)
255 goto fail_malloc_active_pages;
256 if((mode == ALL_AREAS) && (pages_per_area != 0)){
257 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
258 if(!rc->areas)
259 goto fail_malloc_areas;
260 } else {
261 rc->areas = NULL;
262 }
263
264 /* initialize members */
265
266 spin_lock_init(&rc->lock);
267 rc->pages_per_area = pages_per_area;
268 rc->nr_areas = nr_areas;
269 rc->active_area = 0;
270 rc->level = level;
271 rc->buf_size = buf_size;
272 rc->entry_size = sizeof(debug_entry_t) + buf_size;
273 strlcpy(rc->name, name, sizeof(rc->name));
274 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
275 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
276 sizeof(struct dentry*));
277 atomic_set(&(rc->ref_count), 0);
278
279 return rc;
280
281fail_malloc_areas:
282 kfree(rc->active_pages);
283fail_malloc_active_pages:
284 kfree(rc->active_entries);
285fail_malloc_active_entries:
286 kfree(rc);
287fail_malloc_rc:
288 return NULL;
289}
290
291/*
292 * debug_areas_free
293 * - free all debug areas
294 */
295
296static void
297debug_areas_free(debug_info_t* db_info)
298{
299 int i,j;
300
301 if(!db_info->areas)
302 return;
303 for (i = 0; i < db_info->nr_areas; i++) {
304 for(j = 0; j < db_info->pages_per_area; j++) {
305 kfree(db_info->areas[i][j]);
306 }
307 kfree(db_info->areas[i]);
308 }
309 kfree(db_info->areas);
310 db_info->areas = NULL;
311}
312
313/*
314 * debug_info_free
315 * - free memory debug-info
316 */
317
318static void
319debug_info_free(debug_info_t* db_info){
320 debug_areas_free(db_info);
321 kfree(db_info->active_entries);
322 kfree(db_info->active_pages);
323 kfree(db_info);
324}
325
326/*
327 * debug_info_create
328 * - create new debug-info
329 */
330
331static debug_info_t*
332debug_info_create(const char *name, int pages_per_area, int nr_areas,
333 int buf_size, mode_t mode)
334{
335 debug_info_t* rc;
336
337 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
338 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
339 if(!rc)
340 goto out;
341
342 rc->mode = mode & ~S_IFMT;
343
344 /* create root directory */
345 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
346 debug_debugfs_root_entry);
347
348 /* append new element to linked list */
349 if (!debug_area_first) {
350 /* first element in list */
351 debug_area_first = rc;
352 rc->prev = NULL;
353 } else {
354 /* append element to end of list */
355 debug_area_last->next = rc;
356 rc->prev = debug_area_last;
357 }
358 debug_area_last = rc;
359 rc->next = NULL;
360
361 debug_info_get(rc);
362out:
363 return rc;
364}
365
366/*
367 * debug_info_copy
368 * - copy debug-info
369 */
370
371static debug_info_t*
372debug_info_copy(debug_info_t* in, int mode)
373{
374 int i,j;
375 debug_info_t* rc;
376 unsigned long flags;
377
378 /* get a consistent copy of the debug areas */
379 do {
380 rc = debug_info_alloc(in->name, in->pages_per_area,
381 in->nr_areas, in->buf_size, in->level, mode);
382 spin_lock_irqsave(&in->lock, flags);
383 if(!rc)
384 goto out;
385 /* has something changed in the meantime ? */
386 if((rc->pages_per_area == in->pages_per_area) &&
387 (rc->nr_areas == in->nr_areas)) {
388 break;
389 }
390 spin_unlock_irqrestore(&in->lock, flags);
391 debug_info_free(rc);
392 } while (1);
393
394 if (mode == NO_AREAS)
395 goto out;
396
397 for(i = 0; i < in->nr_areas; i++){
398 for(j = 0; j < in->pages_per_area; j++) {
399 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
400 }
401 }
402out:
403 spin_unlock_irqrestore(&in->lock, flags);
404 return rc;
405}
406
407/*
408 * debug_info_get
409 * - increments reference count for debug-info
410 */
411
412static void
413debug_info_get(debug_info_t * db_info)
414{
415 if (db_info)
416 atomic_inc(&db_info->ref_count);
417}
418
419/*
420 * debug_info_put:
421 * - decreases reference count for debug-info and frees it if necessary
422 */
423
424static void
425debug_info_put(debug_info_t *db_info)
426{
427 int i;
428
429 if (!db_info)
430 return;
431 if (atomic_dec_and_test(&db_info->ref_count)) {
432 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
433 if (!db_info->views[i])
434 continue;
435 debugfs_remove(db_info->debugfs_entries[i]);
436 }
437 debugfs_remove(db_info->debugfs_root_entry);
438 if(db_info == debug_area_first)
439 debug_area_first = db_info->next;
440 if(db_info == debug_area_last)
441 debug_area_last = db_info->prev;
442 if(db_info->prev) db_info->prev->next = db_info->next;
443 if(db_info->next) db_info->next->prev = db_info->prev;
444 debug_info_free(db_info);
445 }
446}
447
448/*
449 * debug_format_entry:
450 * - format one debug entry and return size of formated data
451 */
452
453static int
454debug_format_entry(file_private_info_t *p_info)
455{
456 debug_info_t *id_snap = p_info->debug_info_snap;
457 struct debug_view *view = p_info->view;
458 debug_entry_t *act_entry;
459 size_t len = 0;
460 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
461 /* print prolog */
462 if (view->prolog_proc)
463 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
464 goto out;
465 }
466 if (!id_snap->areas) /* this is true, if we have a prolog only view */
467 goto out; /* or if 'pages_per_area' is 0 */
468 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
469 [p_info->act_page] + p_info->act_entry);
470
471 if (act_entry->id.stck == 0LL)
472 goto out; /* empty entry */
473 if (view->header_proc)
474 len += view->header_proc(id_snap, view, p_info->act_area,
475 act_entry, p_info->temp_buf + len);
476 if (view->format_proc)
477 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
478 DEBUG_DATA(act_entry));
479out:
480 return len;
481}
482
483/*
484 * debug_next_entry:
485 * - goto next entry in p_info
486 */
487
488static inline int
489debug_next_entry(file_private_info_t *p_info)
490{
491 debug_info_t *id;
492
493 id = p_info->debug_info_snap;
494 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
495 p_info->act_entry = 0;
496 p_info->act_page = 0;
497 goto out;
498 }
499 if(!id->areas)
500 return 1;
501 p_info->act_entry += id->entry_size;
502 /* switch to next page, if we reached the end of the page */
503 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
504 /* next page */
505 p_info->act_entry = 0;
506 p_info->act_page += 1;
507 if((p_info->act_page % id->pages_per_area) == 0) {
508 /* next area */
509 p_info->act_area++;
510 p_info->act_page=0;
511 }
512 if(p_info->act_area >= id->nr_areas)
513 return 1;
514 }
515out:
516 return 0;
517}
518
519/*
520 * debug_output:
521 * - called for user read()
522 * - copies formated debug entries to the user buffer
523 */
524
525static ssize_t
526debug_output(struct file *file, /* file descriptor */
527 char __user *user_buf, /* user buffer */
528 size_t len, /* length of buffer */
529 loff_t *offset) /* offset in the file */
530{
531 size_t count = 0;
532 size_t entry_offset;
533 file_private_info_t *p_info;
534
535 p_info = ((file_private_info_t *) file->private_data);
536 if (*offset != p_info->offset)
537 return -EPIPE;
538 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
539 return 0;
540 entry_offset = p_info->act_entry_offset;
541 while(count < len){
542 int formatted_line_size;
543 int formatted_line_residue;
544 int user_buf_residue;
545 size_t copy_size;
546
547 formatted_line_size = debug_format_entry(p_info);
548 formatted_line_residue = formatted_line_size - entry_offset;
549 user_buf_residue = len-count;
550 copy_size = min(user_buf_residue, formatted_line_residue);
551 if(copy_size){
552 if (copy_to_user(user_buf + count, p_info->temp_buf
553 + entry_offset, copy_size))
554 return -EFAULT;
555 count += copy_size;
556 entry_offset += copy_size;
557 }
558 if(copy_size == formatted_line_residue){
559 entry_offset = 0;
560 if(debug_next_entry(p_info))
561 goto out;
562 }
563 }
564out:
565 p_info->offset = *offset + count;
566 p_info->act_entry_offset = entry_offset;
567 *offset = p_info->offset;
568 return count;
569}
570
571/*
572 * debug_input:
573 * - called for user write()
574 * - calls input function of view
575 */
576
577static ssize_t
578debug_input(struct file *file, const char __user *user_buf, size_t length,
579 loff_t *offset)
580{
581 int rc = 0;
582 file_private_info_t *p_info;
583
584 mutex_lock(&debug_mutex);
585 p_info = ((file_private_info_t *) file->private_data);
586 if (p_info->view->input_proc)
587 rc = p_info->view->input_proc(p_info->debug_info_org,
588 p_info->view, file, user_buf,
589 length, offset);
590 else
591 rc = -EPERM;
592 mutex_unlock(&debug_mutex);
593 return rc; /* number of input characters */
594}
595
596/*
597 * debug_open:
598 * - called for user open()
599 * - copies formated output to private_data area of the file
600 * handle
601 */
602
603static int
604debug_open(struct inode *inode, struct file *file)
605{
606 int i, rc = 0;
607 file_private_info_t *p_info;
608 debug_info_t *debug_info, *debug_info_snapshot;
609
610 mutex_lock(&debug_mutex);
611 debug_info = file->f_path.dentry->d_inode->i_private;
612 /* find debug view */
613 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
614 if (!debug_info->views[i])
615 continue;
616 else if (debug_info->debugfs_entries[i] ==
617 file->f_path.dentry) {
618 goto found; /* found view ! */
619 }
620 }
621 /* no entry found */
622 rc = -EINVAL;
623 goto out;
624
625found:
626
627 /* Make snapshot of current debug areas to get it consistent. */
628 /* To copy all the areas is only needed, if we have a view which */
629 /* formats the debug areas. */
630
631 if(!debug_info->views[i]->format_proc &&
632 !debug_info->views[i]->header_proc){
633 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
634 } else {
635 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
636 }
637
638 if(!debug_info_snapshot){
639 rc = -ENOMEM;
640 goto out;
641 }
642 p_info = kmalloc(sizeof(file_private_info_t),
643 GFP_KERNEL);
644 if(!p_info){
645 debug_info_free(debug_info_snapshot);
646 rc = -ENOMEM;
647 goto out;
648 }
649 p_info->offset = 0;
650 p_info->debug_info_snap = debug_info_snapshot;
651 p_info->debug_info_org = debug_info;
652 p_info->view = debug_info->views[i];
653 p_info->act_area = 0;
654 p_info->act_page = 0;
655 p_info->act_entry = DEBUG_PROLOG_ENTRY;
656 p_info->act_entry_offset = 0;
657 file->private_data = p_info;
658 debug_info_get(debug_info);
659 nonseekable_open(inode, file);
660out:
661 mutex_unlock(&debug_mutex);
662 return rc;
663}
664
665/*
666 * debug_close:
667 * - called for user close()
668 * - deletes private_data area of the file handle
669 */
670
671static int
672debug_close(struct inode *inode, struct file *file)
673{
674 file_private_info_t *p_info;
675 p_info = (file_private_info_t *) file->private_data;
676 if(p_info->debug_info_snap)
677 debug_info_free(p_info->debug_info_snap);
678 debug_info_put(p_info->debug_info_org);
679 kfree(file->private_data);
680 return 0; /* success */
681}
682
683/*
684 * debug_register_mode:
685 * - Creates and initializes debug area for the caller
686 * The mode parameter allows to specify access rights for the s390dbf files
687 * - Returns handle for debug area
688 */
689
690debug_info_t *debug_register_mode(const char *name, int pages_per_area,
691 int nr_areas, int buf_size, mode_t mode,
692 uid_t uid, gid_t gid)
693{
694 debug_info_t *rc = NULL;
695
696 /* Since debugfs currently does not support uid/gid other than root, */
697 /* we do not allow gid/uid != 0 until we get support for that. */
698 if ((uid != 0) || (gid != 0))
699 pr_warning("Root becomes the owner of all s390dbf files "
700 "in sysfs\n");
701 BUG_ON(!initialized);
702 mutex_lock(&debug_mutex);
703
704 /* create new debug_info */
705
706 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
707 if(!rc)
708 goto out;
709 debug_register_view(rc, &debug_level_view);
710 debug_register_view(rc, &debug_flush_view);
711 debug_register_view(rc, &debug_pages_view);
712out:
713 if (!rc){
714 pr_err("Registering debug feature %s failed\n", name);
715 }
716 mutex_unlock(&debug_mutex);
717 return rc;
718}
719EXPORT_SYMBOL(debug_register_mode);
720
721/*
722 * debug_register:
723 * - creates and initializes debug area for the caller
724 * - returns handle for debug area
725 */
726
727debug_info_t *debug_register(const char *name, int pages_per_area,
728 int nr_areas, int buf_size)
729{
730 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
731 S_IRUSR | S_IWUSR, 0, 0);
732}
733
734/*
735 * debug_unregister:
736 * - give back debug area
737 */
738
739void
740debug_unregister(debug_info_t * id)
741{
742 if (!id)
743 goto out;
744 mutex_lock(&debug_mutex);
745 debug_info_put(id);
746 mutex_unlock(&debug_mutex);
747
748out:
749 return;
750}
751
752/*
753 * debug_set_size:
754 * - set area size (number of pages) and number of areas
755 */
756static int
757debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
758{
759 unsigned long flags;
760 debug_entry_t *** new_areas;
761 int rc=0;
762
763 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
764 return -EINVAL;
765 if(pages_per_area > 0){
766 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
767 if(!new_areas) {
768 pr_info("Allocating memory for %i pages failed\n",
769 pages_per_area);
770 rc = -ENOMEM;
771 goto out;
772 }
773 } else {
774 new_areas = NULL;
775 }
776 spin_lock_irqsave(&id->lock,flags);
777 debug_areas_free(id);
778 id->areas = new_areas;
779 id->nr_areas = nr_areas;
780 id->pages_per_area = pages_per_area;
781 id->active_area = 0;
782 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
783 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
784 spin_unlock_irqrestore(&id->lock,flags);
785 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
786out:
787 return rc;
788}
789
790/*
791 * debug_set_level:
792 * - set actual debug level
793 */
794
795void
796debug_set_level(debug_info_t* id, int new_level)
797{
798 unsigned long flags;
799 if(!id)
800 return;
801 spin_lock_irqsave(&id->lock,flags);
802 if(new_level == DEBUG_OFF_LEVEL){
803 id->level = DEBUG_OFF_LEVEL;
804 pr_info("%s: switched off\n",id->name);
805 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
806 pr_info("%s: level %i is out of range (%i - %i)\n",
807 id->name, new_level, 0, DEBUG_MAX_LEVEL);
808 } else {
809 id->level = new_level;
810 }
811 spin_unlock_irqrestore(&id->lock,flags);
812}
813
814
815/*
816 * proceed_active_entry:
817 * - set active entry to next in the ring buffer
818 */
819
820static inline void
821proceed_active_entry(debug_info_t * id)
822{
823 if ((id->active_entries[id->active_area] += id->entry_size)
824 > (PAGE_SIZE - id->entry_size)){
825 id->active_entries[id->active_area] = 0;
826 id->active_pages[id->active_area] =
827 (id->active_pages[id->active_area] + 1) %
828 id->pages_per_area;
829 }
830}
831
832/*
833 * proceed_active_area:
834 * - set active area to next in the ring buffer
835 */
836
837static inline void
838proceed_active_area(debug_info_t * id)
839{
840 id->active_area++;
841 id->active_area = id->active_area % id->nr_areas;
842}
843
844/*
845 * get_active_entry:
846 */
847
848static inline debug_entry_t*
849get_active_entry(debug_info_t * id)
850{
851 return (debug_entry_t *) (((char *) id->areas[id->active_area]
852 [id->active_pages[id->active_area]]) +
853 id->active_entries[id->active_area]);
854}
855
856/*
857 * debug_finish_entry:
858 * - set timestamp, caller address, cpu number etc.
859 */
860
861static inline void
862debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
863 int exception)
864{
865 active->id.stck = get_clock();
866 active->id.fields.cpuid = smp_processor_id();
867 active->caller = __builtin_return_address(0);
868 active->id.fields.exception = exception;
869 active->id.fields.level = level;
870 proceed_active_entry(id);
871 if(exception)
872 proceed_active_area(id);
873}
874
875static int debug_stoppable=1;
876static int debug_active=1;
877
878#define CTL_S390DBF_STOPPABLE 5678
879#define CTL_S390DBF_ACTIVE 5679
880
881/*
882 * proc handler for the running debug_active sysctl
883 * always allow read, allow write only if debug_stoppable is set or
884 * if debug_active is already off
885 */
886static int
887s390dbf_procactive(ctl_table *table, int write,
888 void __user *buffer, size_t *lenp, loff_t *ppos)
889{
890 if (!write || debug_stoppable || !debug_active)
891 return proc_dointvec(table, write, buffer, lenp, ppos);
892 else
893 return 0;
894}
895
896
897static struct ctl_table s390dbf_table[] = {
898 {
899 .procname = "debug_stoppable",
900 .data = &debug_stoppable,
901 .maxlen = sizeof(int),
902 .mode = S_IRUGO | S_IWUSR,
903 .proc_handler = proc_dointvec,
904 },
905 {
906 .procname = "debug_active",
907 .data = &debug_active,
908 .maxlen = sizeof(int),
909 .mode = S_IRUGO | S_IWUSR,
910 .proc_handler = s390dbf_procactive,
911 },
912 { }
913};
914
915static struct ctl_table s390dbf_dir_table[] = {
916 {
917 .procname = "s390dbf",
918 .maxlen = 0,
919 .mode = S_IRUGO | S_IXUGO,
920 .child = s390dbf_table,
921 },
922 { }
923};
924
925static struct ctl_table_header *s390dbf_sysctl_header;
926
927void
928debug_stop_all(void)
929{
930 if (debug_stoppable)
931 debug_active = 0;
932}
933
934
935/*
936 * debug_event_common:
937 * - write debug entry with given size
938 */
939
940debug_entry_t*
941debug_event_common(debug_info_t * id, int level, const void *buf, int len)
942{
943 unsigned long flags;
944 debug_entry_t *active;
945
946 if (!debug_active || !id->areas)
947 return NULL;
948 spin_lock_irqsave(&id->lock, flags);
949 active = get_active_entry(id);
950 memset(DEBUG_DATA(active), 0, id->buf_size);
951 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
952 debug_finish_entry(id, active, level, 0);
953 spin_unlock_irqrestore(&id->lock, flags);
954
955 return active;
956}
957
958/*
959 * debug_exception_common:
960 * - write debug entry with given size and switch to next debug area
961 */
962
963debug_entry_t
964*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
965{
966 unsigned long flags;
967 debug_entry_t *active;
968
969 if (!debug_active || !id->areas)
970 return NULL;
971 spin_lock_irqsave(&id->lock, flags);
972 active = get_active_entry(id);
973 memset(DEBUG_DATA(active), 0, id->buf_size);
974 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
975 debug_finish_entry(id, active, level, 1);
976 spin_unlock_irqrestore(&id->lock, flags);
977
978 return active;
979}
980
981/*
982 * counts arguments in format string for sprintf view
983 */
984
985static inline int
986debug_count_numargs(char *string)
987{
988 int numargs=0;
989
990 while(*string) {
991 if(*string++=='%')
992 numargs++;
993 }
994 return(numargs);
995}
996
997/*
998 * debug_sprintf_event:
999 */
1000
1001debug_entry_t*
1002debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1003{
1004 va_list ap;
1005 int numargs,idx;
1006 unsigned long flags;
1007 debug_sprintf_entry_t *curr_event;
1008 debug_entry_t *active;
1009
1010 if((!id) || (level > id->level))
1011 return NULL;
1012 if (!debug_active || !id->areas)
1013 return NULL;
1014 numargs=debug_count_numargs(string);
1015
1016 spin_lock_irqsave(&id->lock, flags);
1017 active = get_active_entry(id);
1018 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1019 va_start(ap,string);
1020 curr_event->string=string;
1021 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1022 curr_event->args[idx]=va_arg(ap,long);
1023 va_end(ap);
1024 debug_finish_entry(id, active, level, 0);
1025 spin_unlock_irqrestore(&id->lock, flags);
1026
1027 return active;
1028}
1029
1030/*
1031 * debug_sprintf_exception:
1032 */
1033
1034debug_entry_t*
1035debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1036{
1037 va_list ap;
1038 int numargs,idx;
1039 unsigned long flags;
1040 debug_sprintf_entry_t *curr_event;
1041 debug_entry_t *active;
1042
1043 if((!id) || (level > id->level))
1044 return NULL;
1045 if (!debug_active || !id->areas)
1046 return NULL;
1047
1048 numargs=debug_count_numargs(string);
1049
1050 spin_lock_irqsave(&id->lock, flags);
1051 active = get_active_entry(id);
1052 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1053 va_start(ap,string);
1054 curr_event->string=string;
1055 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1056 curr_event->args[idx]=va_arg(ap,long);
1057 va_end(ap);
1058 debug_finish_entry(id, active, level, 1);
1059 spin_unlock_irqrestore(&id->lock, flags);
1060
1061 return active;
1062}
1063
1064/*
1065 * debug_init:
1066 * - is called exactly once to initialize the debug feature
1067 */
1068
1069static int
1070__init debug_init(void)
1071{
1072 int rc = 0;
1073
1074 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1075 mutex_lock(&debug_mutex);
1076 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1077 initialized = 1;
1078 mutex_unlock(&debug_mutex);
1079
1080 return rc;
1081}
1082
1083/*
1084 * debug_register_view:
1085 */
1086
1087int
1088debug_register_view(debug_info_t * id, struct debug_view *view)
1089{
1090 int rc = 0;
1091 int i;
1092 unsigned long flags;
1093 mode_t mode;
1094 struct dentry *pde;
1095
1096 if (!id)
1097 goto out;
1098 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1099 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1100 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1101 if (!view->input_proc)
1102 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1103 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1104 id , &debug_file_ops);
1105 if (!pde){
1106 pr_err("Registering view %s/%s failed due to out of "
1107 "memory\n", id->name,view->name);
1108 rc = -1;
1109 goto out;
1110 }
1111 spin_lock_irqsave(&id->lock, flags);
1112 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1113 if (!id->views[i])
1114 break;
1115 }
1116 if (i == DEBUG_MAX_VIEWS) {
1117 pr_err("Registering view %s/%s would exceed the maximum "
1118 "number of views %i\n", id->name, view->name, i);
1119 debugfs_remove(pde);
1120 rc = -1;
1121 } else {
1122 id->views[i] = view;
1123 id->debugfs_entries[i] = pde;
1124 }
1125 spin_unlock_irqrestore(&id->lock, flags);
1126out:
1127 return rc;
1128}
1129
1130/*
1131 * debug_unregister_view:
1132 */
1133
1134int
1135debug_unregister_view(debug_info_t * id, struct debug_view *view)
1136{
1137 int rc = 0;
1138 int i;
1139 unsigned long flags;
1140
1141 if (!id)
1142 goto out;
1143 spin_lock_irqsave(&id->lock, flags);
1144 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1145 if (id->views[i] == view)
1146 break;
1147 }
1148 if (i == DEBUG_MAX_VIEWS)
1149 rc = -1;
1150 else {
1151 debugfs_remove(id->debugfs_entries[i]);
1152 id->views[i] = NULL;
1153 }
1154 spin_unlock_irqrestore(&id->lock, flags);
1155out:
1156 return rc;
1157}
1158
1159static inline char *
1160debug_get_user_string(const char __user *user_buf, size_t user_len)
1161{
1162 char* buffer;
1163
1164 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1165 if (!buffer)
1166 return ERR_PTR(-ENOMEM);
1167 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1168 kfree(buffer);
1169 return ERR_PTR(-EFAULT);
1170 }
1171 /* got the string, now strip linefeed. */
1172 if (buffer[user_len - 1] == '\n')
1173 buffer[user_len - 1] = 0;
1174 else
1175 buffer[user_len] = 0;
1176 return buffer;
1177}
1178
1179static inline int
1180debug_get_uint(char *buf)
1181{
1182 int rc;
1183
1184 buf = skip_spaces(buf);
1185 rc = simple_strtoul(buf, &buf, 10);
1186 if(*buf){
1187 rc = -EINVAL;
1188 }
1189 return rc;
1190}
1191
1192/*
1193 * functions for debug-views
1194 ***********************************
1195*/
1196
1197/*
1198 * prints out actual debug level
1199 */
1200
1201static int
1202debug_prolog_pages_fn(debug_info_t * id,
1203 struct debug_view *view, char *out_buf)
1204{
1205 return sprintf(out_buf, "%i\n", id->pages_per_area);
1206}
1207
1208/*
1209 * reads new size (number of pages per debug area)
1210 */
1211
1212static int
1213debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1214 struct file *file, const char __user *user_buf,
1215 size_t user_len, loff_t * offset)
1216{
1217 char *str;
1218 int rc,new_pages;
1219
1220 if (user_len > 0x10000)
1221 user_len = 0x10000;
1222 if (*offset != 0){
1223 rc = -EPIPE;
1224 goto out;
1225 }
1226 str = debug_get_user_string(user_buf,user_len);
1227 if(IS_ERR(str)){
1228 rc = PTR_ERR(str);
1229 goto out;
1230 }
1231 new_pages = debug_get_uint(str);
1232 if(new_pages < 0){
1233 rc = -EINVAL;
1234 goto free_str;
1235 }
1236 rc = debug_set_size(id,id->nr_areas, new_pages);
1237 if(rc != 0){
1238 rc = -EINVAL;
1239 goto free_str;
1240 }
1241 rc = user_len;
1242free_str:
1243 kfree(str);
1244out:
1245 *offset += user_len;
1246 return rc; /* number of input characters */
1247}
1248
1249/*
1250 * prints out actual debug level
1251 */
1252
1253static int
1254debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1255{
1256 int rc = 0;
1257
1258 if(id->level == DEBUG_OFF_LEVEL) {
1259 rc = sprintf(out_buf,"-\n");
1260 }
1261 else {
1262 rc = sprintf(out_buf, "%i\n", id->level);
1263 }
1264 return rc;
1265}
1266
1267/*
1268 * reads new debug level
1269 */
1270
1271static int
1272debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1273 struct file *file, const char __user *user_buf,
1274 size_t user_len, loff_t * offset)
1275{
1276 char *str;
1277 int rc,new_level;
1278
1279 if (user_len > 0x10000)
1280 user_len = 0x10000;
1281 if (*offset != 0){
1282 rc = -EPIPE;
1283 goto out;
1284 }
1285 str = debug_get_user_string(user_buf,user_len);
1286 if(IS_ERR(str)){
1287 rc = PTR_ERR(str);
1288 goto out;
1289 }
1290 if(str[0] == '-'){
1291 debug_set_level(id, DEBUG_OFF_LEVEL);
1292 rc = user_len;
1293 goto free_str;
1294 } else {
1295 new_level = debug_get_uint(str);
1296 }
1297 if(new_level < 0) {
1298 pr_warning("%s is not a valid level for a debug "
1299 "feature\n", str);
1300 rc = -EINVAL;
1301 } else {
1302 debug_set_level(id, new_level);
1303 rc = user_len;
1304 }
1305free_str:
1306 kfree(str);
1307out:
1308 *offset += user_len;
1309 return rc; /* number of input characters */
1310}
1311
1312
1313/*
1314 * flushes debug areas
1315 */
1316
1317static void debug_flush(debug_info_t* id, int area)
1318{
1319 unsigned long flags;
1320 int i,j;
1321
1322 if(!id || !id->areas)
1323 return;
1324 spin_lock_irqsave(&id->lock,flags);
1325 if(area == DEBUG_FLUSH_ALL){
1326 id->active_area = 0;
1327 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1328 for (i = 0; i < id->nr_areas; i++) {
1329 id->active_pages[i] = 0;
1330 for(j = 0; j < id->pages_per_area; j++) {
1331 memset(id->areas[i][j], 0, PAGE_SIZE);
1332 }
1333 }
1334 } else if(area >= 0 && area < id->nr_areas) {
1335 id->active_entries[area] = 0;
1336 id->active_pages[area] = 0;
1337 for(i = 0; i < id->pages_per_area; i++) {
1338 memset(id->areas[area][i],0,PAGE_SIZE);
1339 }
1340 }
1341 spin_unlock_irqrestore(&id->lock,flags);
1342}
1343
1344/*
1345 * view function: flushes debug areas
1346 */
1347
1348static int
1349debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1350 struct file *file, const char __user *user_buf,
1351 size_t user_len, loff_t * offset)
1352{
1353 char input_buf[1];
1354 int rc = user_len;
1355
1356 if (user_len > 0x10000)
1357 user_len = 0x10000;
1358 if (*offset != 0){
1359 rc = -EPIPE;
1360 goto out;
1361 }
1362 if (copy_from_user(input_buf, user_buf, 1)){
1363 rc = -EFAULT;
1364 goto out;
1365 }
1366 if(input_buf[0] == '-') {
1367 debug_flush(id, DEBUG_FLUSH_ALL);
1368 goto out;
1369 }
1370 if (isdigit(input_buf[0])) {
1371 int area = ((int) input_buf[0] - (int) '0');
1372 debug_flush(id, area);
1373 goto out;
1374 }
1375
1376 pr_info("Flushing debug data failed because %c is not a valid "
1377 "area\n", input_buf[0]);
1378
1379out:
1380 *offset += user_len;
1381 return rc; /* number of input characters */
1382}
1383
1384/*
1385 * prints debug header in raw format
1386 */
1387
1388static int
1389debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1390 int area, debug_entry_t * entry, char *out_buf)
1391{
1392 int rc;
1393
1394 rc = sizeof(debug_entry_t);
1395 memcpy(out_buf,entry,sizeof(debug_entry_t));
1396 return rc;
1397}
1398
1399/*
1400 * prints debug data in raw format
1401 */
1402
1403static int
1404debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1405 char *out_buf, const char *in_buf)
1406{
1407 int rc;
1408
1409 rc = id->buf_size;
1410 memcpy(out_buf, in_buf, id->buf_size);
1411 return rc;
1412}
1413
1414/*
1415 * prints debug data in hex/ascii format
1416 */
1417
1418static int
1419debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1420 char *out_buf, const char *in_buf)
1421{
1422 int i, rc = 0;
1423
1424 for (i = 0; i < id->buf_size; i++) {
1425 rc += sprintf(out_buf + rc, "%02x ",
1426 ((unsigned char *) in_buf)[i]);
1427 }
1428 rc += sprintf(out_buf + rc, "| ");
1429 for (i = 0; i < id->buf_size; i++) {
1430 unsigned char c = in_buf[i];
1431 if (!isprint(c))
1432 rc += sprintf(out_buf + rc, ".");
1433 else
1434 rc += sprintf(out_buf + rc, "%c", c);
1435 }
1436 rc += sprintf(out_buf + rc, "\n");
1437 return rc;
1438}
1439
1440/*
1441 * prints header for debug entry
1442 */
1443
1444int
1445debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1446 int area, debug_entry_t * entry, char *out_buf)
1447{
1448 struct timespec time_spec;
1449 char *except_str;
1450 unsigned long caller;
1451 int rc = 0;
1452 unsigned int level;
1453
1454 level = entry->id.fields.level;
1455 stck_to_timespec(entry->id.stck, &time_spec);
1456
1457 if (entry->id.fields.exception)
1458 except_str = "*";
1459 else
1460 except_str = "-";
1461 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1462 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1463 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1464 except_str, entry->id.fields.cpuid, (void *) caller);
1465 return rc;
1466}
1467
1468/*
1469 * prints debug data sprintf-formated:
1470 * debug_sprinf_event/exception calls must be used together with this view
1471 */
1472
1473#define DEBUG_SPRINTF_MAX_ARGS 10
1474
1475static int
1476debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1477 char *out_buf, debug_sprintf_entry_t *curr_event)
1478{
1479 int num_longs, num_used_args = 0,i, rc = 0;
1480 int index[DEBUG_SPRINTF_MAX_ARGS];
1481
1482 /* count of longs fit into one entry */
1483 num_longs = id->buf_size / sizeof(long);
1484
1485 if(num_longs < 1)
1486 goto out; /* bufsize of entry too small */
1487 if(num_longs == 1) {
1488 /* no args, we use only the string */
1489 strcpy(out_buf, curr_event->string);
1490 rc = strlen(curr_event->string);
1491 goto out;
1492 }
1493
1494 /* number of arguments used for sprintf (without the format string) */
1495 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1496
1497 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1498
1499 for(i = 0; i < num_used_args; i++)
1500 index[i] = i;
1501
1502 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1503 curr_event->args[index[1]], curr_event->args[index[2]],
1504 curr_event->args[index[3]], curr_event->args[index[4]],
1505 curr_event->args[index[5]], curr_event->args[index[6]],
1506 curr_event->args[index[7]], curr_event->args[index[8]],
1507 curr_event->args[index[9]]);
1508
1509out:
1510
1511 return rc;
1512}
1513
1514/*
1515 * clean up module
1516 */
1517static void __exit debug_exit(void)
1518{
1519 debugfs_remove(debug_debugfs_root_entry);
1520 unregister_sysctl_table(s390dbf_sysctl_header);
1521 return;
1522}
1523
1524/*
1525 * module definitions
1526 */
1527postcore_initcall(debug_init);
1528module_exit(debug_exit);
1529MODULE_LICENSE("GPL");
1530
1531EXPORT_SYMBOL(debug_register);
1532EXPORT_SYMBOL(debug_unregister);
1533EXPORT_SYMBOL(debug_set_level);
1534EXPORT_SYMBOL(debug_stop_all);
1535EXPORT_SYMBOL(debug_register_view);
1536EXPORT_SYMBOL(debug_unregister_view);
1537EXPORT_SYMBOL(debug_event_common);
1538EXPORT_SYMBOL(debug_exception_common);
1539EXPORT_SYMBOL(debug_hex_ascii_view);
1540EXPORT_SYMBOL(debug_raw_view);
1541EXPORT_SYMBOL(debug_dflt_header_fn);
1542EXPORT_SYMBOL(debug_sprintf_view);
1543EXPORT_SYMBOL(debug_sprintf_exception);
1544EXPORT_SYMBOL(debug_sprintf_event);