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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, const char *inbuf);
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_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 strscpy(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/**
696 * debug_register_static() - registers a static debug area
697 *
698 * @id: Handle for static debug area
699 * @pages_per_area: Number of pages per area
700 * @nr_areas: Number of debug areas
701 *
702 * Register debug_info_t defined using DEFINE_STATIC_DEBUG_INFO.
703 *
704 * Note: This function is called automatically via an initcall generated by
705 * DEFINE_STATIC_DEBUG_INFO.
706 */
707void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas)
708{
709 unsigned long flags;
710 debug_info_t *copy;
711
712 if (!initialized) {
713 pr_err("Tried to register debug feature %s too early\n",
714 id->name);
715 return;
716 }
717
718 copy = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
719 id->level, ALL_AREAS);
720 if (!copy) {
721 pr_err("Registering debug feature %s failed\n", id->name);
722
723 /* Clear pointers to prevent tracing into released initdata. */
724 spin_lock_irqsave(&id->lock, flags);
725 id->areas = NULL;
726 id->active_pages = NULL;
727 id->active_entries = NULL;
728 spin_unlock_irqrestore(&id->lock, flags);
729
730 return;
731 }
732
733 /* Replace static trace area with dynamic copy. */
734 spin_lock_irqsave(&id->lock, flags);
735 debug_events_append(copy, id);
736 debug_areas_swap(id, copy);
737 spin_unlock_irqrestore(&id->lock, flags);
738
739 /* Clear pointers to initdata and discard copy. */
740 copy->areas = NULL;
741 copy->active_pages = NULL;
742 copy->active_entries = NULL;
743 debug_info_free(copy);
744
745 mutex_lock(&debug_mutex);
746 _debug_register(id);
747 mutex_unlock(&debug_mutex);
748}
749
750/* Remove debugfs entries and remove from internal list. */
751static void _debug_unregister(debug_info_t *id)
752{
753 int i;
754
755 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
756 if (!id->views[i])
757 continue;
758 debugfs_remove(id->debugfs_entries[i]);
759 }
760 debugfs_remove(id->debugfs_root_entry);
761 if (id == debug_area_first)
762 debug_area_first = id->next;
763 if (id == debug_area_last)
764 debug_area_last = id->prev;
765 if (id->prev)
766 id->prev->next = id->next;
767 if (id->next)
768 id->next->prev = id->prev;
769}
770
771/**
772 * debug_unregister() - give back debug area.
773 *
774 * @id: handle for debug log
775 *
776 * Return:
777 * none
778 */
779void debug_unregister(debug_info_t *id)
780{
781 if (!id)
782 return;
783 mutex_lock(&debug_mutex);
784 _debug_unregister(id);
785 mutex_unlock(&debug_mutex);
786
787 debug_info_put(id);
788}
789EXPORT_SYMBOL(debug_unregister);
790
791/*
792 * debug_set_size:
793 * - set area size (number of pages) and number of areas
794 */
795static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
796{
797 debug_info_t *new_id;
798 unsigned long flags;
799
800 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
801 return -EINVAL;
802
803 new_id = debug_info_alloc("", pages_per_area, nr_areas, id->buf_size,
804 id->level, ALL_AREAS);
805 if (!new_id) {
806 pr_info("Allocating memory for %i pages failed\n",
807 pages_per_area);
808 return -ENOMEM;
809 }
810
811 spin_lock_irqsave(&id->lock, flags);
812 debug_events_append(new_id, id);
813 debug_areas_swap(new_id, id);
814 debug_info_free(new_id);
815 spin_unlock_irqrestore(&id->lock, flags);
816 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
817
818 return 0;
819}
820
821/**
822 * debug_set_level() - Sets new actual debug level if new_level is valid.
823 *
824 * @id: handle for debug log
825 * @new_level: new debug level
826 *
827 * Return:
828 * none
829 */
830void debug_set_level(debug_info_t *id, int new_level)
831{
832 unsigned long flags;
833
834 if (!id)
835 return;
836
837 if (new_level == DEBUG_OFF_LEVEL) {
838 pr_info("%s: switched off\n", id->name);
839 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
840 pr_info("%s: level %i is out of range (%i - %i)\n",
841 id->name, new_level, 0, DEBUG_MAX_LEVEL);
842 return;
843 }
844
845 spin_lock_irqsave(&id->lock, flags);
846 id->level = new_level;
847 spin_unlock_irqrestore(&id->lock, flags);
848}
849EXPORT_SYMBOL(debug_set_level);
850
851/*
852 * proceed_active_entry:
853 * - set active entry to next in the ring buffer
854 */
855static inline void proceed_active_entry(debug_info_t *id)
856{
857 if ((id->active_entries[id->active_area] += id->entry_size)
858 > (PAGE_SIZE - id->entry_size)) {
859 id->active_entries[id->active_area] = 0;
860 id->active_pages[id->active_area] =
861 (id->active_pages[id->active_area] + 1) %
862 id->pages_per_area;
863 }
864}
865
866/*
867 * proceed_active_area:
868 * - set active area to next in the ring buffer
869 */
870static inline void proceed_active_area(debug_info_t *id)
871{
872 id->active_area++;
873 id->active_area = id->active_area % id->nr_areas;
874}
875
876/*
877 * get_active_entry:
878 */
879static inline debug_entry_t *get_active_entry(debug_info_t *id)
880{
881 return (debug_entry_t *) (((char *) id->areas[id->active_area]
882 [id->active_pages[id->active_area]]) +
883 id->active_entries[id->active_area]);
884}
885
886/* Swap debug areas of a and b. */
887static void debug_areas_swap(debug_info_t *a, debug_info_t *b)
888{
889 swap(a->nr_areas, b->nr_areas);
890 swap(a->pages_per_area, b->pages_per_area);
891 swap(a->areas, b->areas);
892 swap(a->active_area, b->active_area);
893 swap(a->active_pages, b->active_pages);
894 swap(a->active_entries, b->active_entries);
895}
896
897/* Append all debug events in active area from source to destination log. */
898static void debug_events_append(debug_info_t *dest, debug_info_t *src)
899{
900 debug_entry_t *from, *to, *last;
901
902 if (!src->areas || !dest->areas)
903 return;
904
905 /* Loop over all entries in src, starting with oldest. */
906 from = get_active_entry(src);
907 last = from;
908 do {
909 if (from->clock != 0LL) {
910 to = get_active_entry(dest);
911 memset(to, 0, dest->entry_size);
912 memcpy(to, from, min(src->entry_size,
913 dest->entry_size));
914 proceed_active_entry(dest);
915 }
916
917 proceed_active_entry(src);
918 from = get_active_entry(src);
919 } while (from != last);
920}
921
922/*
923 * debug_finish_entry:
924 * - set timestamp, caller address, cpu number etc.
925 */
926
927static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
928 int level, int exception)
929{
930 unsigned long timestamp;
931 union tod_clock clk;
932
933 store_tod_clock_ext(&clk);
934 timestamp = clk.us;
935 timestamp -= TOD_UNIX_EPOCH >> 12;
936 active->clock = timestamp;
937 active->cpu = smp_processor_id();
938 active->caller = __builtin_return_address(0);
939 active->exception = exception;
940 active->level = level;
941 proceed_active_entry(id);
942 if (exception)
943 proceed_active_area(id);
944}
945
946static int debug_stoppable = 1;
947static int debug_active = 1;
948
949#define CTL_S390DBF_STOPPABLE 5678
950#define CTL_S390DBF_ACTIVE 5679
951
952/*
953 * proc handler for the running debug_active sysctl
954 * always allow read, allow write only if debug_stoppable is set or
955 * if debug_active is already off
956 */
957static int s390dbf_procactive(struct ctl_table *table, int write,
958 void *buffer, size_t *lenp, loff_t *ppos)
959{
960 if (!write || debug_stoppable || !debug_active)
961 return proc_dointvec(table, write, buffer, lenp, ppos);
962 else
963 return 0;
964}
965
966static struct ctl_table s390dbf_table[] = {
967 {
968 .procname = "debug_stoppable",
969 .data = &debug_stoppable,
970 .maxlen = sizeof(int),
971 .mode = S_IRUGO | S_IWUSR,
972 .proc_handler = proc_dointvec,
973 },
974 {
975 .procname = "debug_active",
976 .data = &debug_active,
977 .maxlen = sizeof(int),
978 .mode = S_IRUGO | S_IWUSR,
979 .proc_handler = s390dbf_procactive,
980 },
981 { }
982};
983
984static struct ctl_table s390dbf_dir_table[] = {
985 {
986 .procname = "s390dbf",
987 .maxlen = 0,
988 .mode = S_IRUGO | S_IXUGO,
989 .child = s390dbf_table,
990 },
991 { }
992};
993
994static struct ctl_table_header *s390dbf_sysctl_header;
995
996/**
997 * debug_stop_all() - stops the debug feature if stopping is allowed.
998 *
999 * Return:
1000 * - none
1001 *
1002 * Currently used in case of a kernel oops.
1003 */
1004void debug_stop_all(void)
1005{
1006 if (debug_stoppable)
1007 debug_active = 0;
1008}
1009EXPORT_SYMBOL(debug_stop_all);
1010
1011/**
1012 * debug_set_critical() - event/exception functions try lock instead of spin.
1013 *
1014 * Return:
1015 * - none
1016 *
1017 * Currently used in case of stopping all CPUs but the current one.
1018 * Once in this state, functions to write a debug entry for an
1019 * event or exception no longer spin on the debug area lock,
1020 * but only try to get it and fail if they do not get the lock.
1021 */
1022void debug_set_critical(void)
1023{
1024 debug_critical = 1;
1025}
1026
1027/*
1028 * debug_event_common:
1029 * - write debug entry with given size
1030 */
1031debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
1032 int len)
1033{
1034 debug_entry_t *active;
1035 unsigned long flags;
1036
1037 if (!debug_active || !id->areas)
1038 return NULL;
1039 if (debug_critical) {
1040 if (!spin_trylock_irqsave(&id->lock, flags))
1041 return NULL;
1042 } else {
1043 spin_lock_irqsave(&id->lock, flags);
1044 }
1045 do {
1046 active = get_active_entry(id);
1047 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1048 if (len < id->buf_size)
1049 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1050 debug_finish_entry(id, active, level, 0);
1051 len -= id->buf_size;
1052 buf += id->buf_size;
1053 } while (len > 0);
1054
1055 spin_unlock_irqrestore(&id->lock, flags);
1056 return active;
1057}
1058EXPORT_SYMBOL(debug_event_common);
1059
1060/*
1061 * debug_exception_common:
1062 * - write debug entry with given size and switch to next debug area
1063 */
1064debug_entry_t *debug_exception_common(debug_info_t *id, int level,
1065 const void *buf, int len)
1066{
1067 debug_entry_t *active;
1068 unsigned long flags;
1069
1070 if (!debug_active || !id->areas)
1071 return NULL;
1072 if (debug_critical) {
1073 if (!spin_trylock_irqsave(&id->lock, flags))
1074 return NULL;
1075 } else {
1076 spin_lock_irqsave(&id->lock, flags);
1077 }
1078 do {
1079 active = get_active_entry(id);
1080 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1081 if (len < id->buf_size)
1082 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1083 debug_finish_entry(id, active, level, len <= id->buf_size);
1084 len -= id->buf_size;
1085 buf += id->buf_size;
1086 } while (len > 0);
1087
1088 spin_unlock_irqrestore(&id->lock, flags);
1089 return active;
1090}
1091EXPORT_SYMBOL(debug_exception_common);
1092
1093/*
1094 * counts arguments in format string for sprintf view
1095 */
1096static inline int debug_count_numargs(char *string)
1097{
1098 int numargs = 0;
1099
1100 while (*string) {
1101 if (*string++ == '%')
1102 numargs++;
1103 }
1104 return numargs;
1105}
1106
1107/*
1108 * debug_sprintf_event:
1109 */
1110debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1111{
1112 debug_sprintf_entry_t *curr_event;
1113 debug_entry_t *active;
1114 unsigned long flags;
1115 int numargs, idx;
1116 va_list ap;
1117
1118 if (!debug_active || !id->areas)
1119 return NULL;
1120 numargs = debug_count_numargs(string);
1121
1122 if (debug_critical) {
1123 if (!spin_trylock_irqsave(&id->lock, flags))
1124 return NULL;
1125 } else {
1126 spin_lock_irqsave(&id->lock, flags);
1127 }
1128 active = get_active_entry(id);
1129 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1130 va_start(ap, string);
1131 curr_event->string = string;
1132 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1133 curr_event->args[idx] = va_arg(ap, long);
1134 va_end(ap);
1135 debug_finish_entry(id, active, level, 0);
1136 spin_unlock_irqrestore(&id->lock, flags);
1137
1138 return active;
1139}
1140EXPORT_SYMBOL(__debug_sprintf_event);
1141
1142/*
1143 * debug_sprintf_exception:
1144 */
1145debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1146{
1147 debug_sprintf_entry_t *curr_event;
1148 debug_entry_t *active;
1149 unsigned long flags;
1150 int numargs, idx;
1151 va_list ap;
1152
1153 if (!debug_active || !id->areas)
1154 return NULL;
1155
1156 numargs = debug_count_numargs(string);
1157
1158 if (debug_critical) {
1159 if (!spin_trylock_irqsave(&id->lock, flags))
1160 return NULL;
1161 } else {
1162 spin_lock_irqsave(&id->lock, flags);
1163 }
1164 active = get_active_entry(id);
1165 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1166 va_start(ap, string);
1167 curr_event->string = string;
1168 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1169 curr_event->args[idx] = va_arg(ap, long);
1170 va_end(ap);
1171 debug_finish_entry(id, active, level, 1);
1172 spin_unlock_irqrestore(&id->lock, flags);
1173
1174 return active;
1175}
1176EXPORT_SYMBOL(__debug_sprintf_exception);
1177
1178/**
1179 * debug_register_view() - registers new debug view and creates debugfs
1180 * dir entry
1181 *
1182 * @id: handle for debug log
1183 * @view: pointer to debug view struct
1184 *
1185 * Return:
1186 * - 0 : ok
1187 * - < 0: Error
1188 */
1189int debug_register_view(debug_info_t *id, struct debug_view *view)
1190{
1191 unsigned long flags;
1192 struct dentry *pde;
1193 umode_t mode;
1194 int rc = 0;
1195 int i;
1196
1197 if (!id)
1198 goto out;
1199 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1200 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1201 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1202 if (!view->input_proc)
1203 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1204 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1205 id, &debug_file_ops);
1206 spin_lock_irqsave(&id->lock, flags);
1207 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1208 if (!id->views[i])
1209 break;
1210 }
1211 if (i == DEBUG_MAX_VIEWS) {
1212 rc = -1;
1213 } else {
1214 id->views[i] = view;
1215 id->debugfs_entries[i] = pde;
1216 }
1217 spin_unlock_irqrestore(&id->lock, flags);
1218 if (rc) {
1219 pr_err("Registering view %s/%s would exceed the maximum "
1220 "number of views %i\n", id->name, view->name, i);
1221 debugfs_remove(pde);
1222 }
1223out:
1224 return rc;
1225}
1226EXPORT_SYMBOL(debug_register_view);
1227
1228/**
1229 * debug_unregister_view() - unregisters debug view and removes debugfs
1230 * dir entry
1231 *
1232 * @id: handle for debug log
1233 * @view: pointer to debug view struct
1234 *
1235 * Return:
1236 * - 0 : ok
1237 * - < 0: Error
1238 */
1239int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1240{
1241 struct dentry *dentry = NULL;
1242 unsigned long flags;
1243 int i, rc = 0;
1244
1245 if (!id)
1246 goto out;
1247 spin_lock_irqsave(&id->lock, flags);
1248 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1249 if (id->views[i] == view)
1250 break;
1251 }
1252 if (i == DEBUG_MAX_VIEWS) {
1253 rc = -1;
1254 } else {
1255 dentry = id->debugfs_entries[i];
1256 id->views[i] = NULL;
1257 id->debugfs_entries[i] = NULL;
1258 }
1259 spin_unlock_irqrestore(&id->lock, flags);
1260 debugfs_remove(dentry);
1261out:
1262 return rc;
1263}
1264EXPORT_SYMBOL(debug_unregister_view);
1265
1266static inline char *debug_get_user_string(const char __user *user_buf,
1267 size_t user_len)
1268{
1269 char *buffer;
1270
1271 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1272 if (!buffer)
1273 return ERR_PTR(-ENOMEM);
1274 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1275 kfree(buffer);
1276 return ERR_PTR(-EFAULT);
1277 }
1278 /* got the string, now strip linefeed. */
1279 if (buffer[user_len - 1] == '\n')
1280 buffer[user_len - 1] = 0;
1281 else
1282 buffer[user_len] = 0;
1283 return buffer;
1284}
1285
1286static inline int debug_get_uint(char *buf)
1287{
1288 int rc;
1289
1290 buf = skip_spaces(buf);
1291 rc = simple_strtoul(buf, &buf, 10);
1292 if (*buf)
1293 rc = -EINVAL;
1294 return rc;
1295}
1296
1297/*
1298 * functions for debug-views
1299 ***********************************
1300*/
1301
1302/*
1303 * prints out actual debug level
1304 */
1305
1306static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1307 char *out_buf)
1308{
1309 return sprintf(out_buf, "%i\n", id->pages_per_area);
1310}
1311
1312/*
1313 * reads new size (number of pages per debug area)
1314 */
1315
1316static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1317 struct file *file, const char __user *user_buf,
1318 size_t user_len, loff_t *offset)
1319{
1320 int rc, new_pages;
1321 char *str;
1322
1323 if (user_len > 0x10000)
1324 user_len = 0x10000;
1325 if (*offset != 0) {
1326 rc = -EPIPE;
1327 goto out;
1328 }
1329 str = debug_get_user_string(user_buf, user_len);
1330 if (IS_ERR(str)) {
1331 rc = PTR_ERR(str);
1332 goto out;
1333 }
1334 new_pages = debug_get_uint(str);
1335 if (new_pages < 0) {
1336 rc = -EINVAL;
1337 goto free_str;
1338 }
1339 rc = debug_set_size(id, id->nr_areas, new_pages);
1340 if (rc != 0) {
1341 rc = -EINVAL;
1342 goto free_str;
1343 }
1344 rc = user_len;
1345free_str:
1346 kfree(str);
1347out:
1348 *offset += user_len;
1349 return rc; /* number of input characters */
1350}
1351
1352/*
1353 * prints out actual debug level
1354 */
1355static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1356 char *out_buf)
1357{
1358 int rc = 0;
1359
1360 if (id->level == DEBUG_OFF_LEVEL)
1361 rc = sprintf(out_buf, "-\n");
1362 else
1363 rc = sprintf(out_buf, "%i\n", id->level);
1364 return rc;
1365}
1366
1367/*
1368 * reads new debug level
1369 */
1370static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1371 struct file *file, const char __user *user_buf,
1372 size_t user_len, loff_t *offset)
1373{
1374 int rc, new_level;
1375 char *str;
1376
1377 if (user_len > 0x10000)
1378 user_len = 0x10000;
1379 if (*offset != 0) {
1380 rc = -EPIPE;
1381 goto out;
1382 }
1383 str = debug_get_user_string(user_buf, user_len);
1384 if (IS_ERR(str)) {
1385 rc = PTR_ERR(str);
1386 goto out;
1387 }
1388 if (str[0] == '-') {
1389 debug_set_level(id, DEBUG_OFF_LEVEL);
1390 rc = user_len;
1391 goto free_str;
1392 } else {
1393 new_level = debug_get_uint(str);
1394 }
1395 if (new_level < 0) {
1396 pr_warn("%s is not a valid level for a debug feature\n", str);
1397 rc = -EINVAL;
1398 } else {
1399 debug_set_level(id, new_level);
1400 rc = user_len;
1401 }
1402free_str:
1403 kfree(str);
1404out:
1405 *offset += user_len;
1406 return rc; /* number of input characters */
1407}
1408
1409/*
1410 * flushes debug areas
1411 */
1412static void debug_flush(debug_info_t *id, int area)
1413{
1414 unsigned long flags;
1415 int i, j;
1416
1417 if (!id || !id->areas)
1418 return;
1419 spin_lock_irqsave(&id->lock, flags);
1420 if (area == DEBUG_FLUSH_ALL) {
1421 id->active_area = 0;
1422 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1423 for (i = 0; i < id->nr_areas; i++) {
1424 id->active_pages[i] = 0;
1425 for (j = 0; j < id->pages_per_area; j++)
1426 memset(id->areas[i][j], 0, PAGE_SIZE);
1427 }
1428 } else if (area >= 0 && area < id->nr_areas) {
1429 id->active_entries[area] = 0;
1430 id->active_pages[area] = 0;
1431 for (i = 0; i < id->pages_per_area; i++)
1432 memset(id->areas[area][i], 0, PAGE_SIZE);
1433 }
1434 spin_unlock_irqrestore(&id->lock, flags);
1435}
1436
1437/*
1438 * view function: flushes debug areas
1439 */
1440static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1441 struct file *file, const char __user *user_buf,
1442 size_t user_len, loff_t *offset)
1443{
1444 char input_buf[1];
1445 int rc = user_len;
1446
1447 if (user_len > 0x10000)
1448 user_len = 0x10000;
1449 if (*offset != 0) {
1450 rc = -EPIPE;
1451 goto out;
1452 }
1453 if (copy_from_user(input_buf, user_buf, 1)) {
1454 rc = -EFAULT;
1455 goto out;
1456 }
1457 if (input_buf[0] == '-') {
1458 debug_flush(id, DEBUG_FLUSH_ALL);
1459 goto out;
1460 }
1461 if (isdigit(input_buf[0])) {
1462 int area = ((int) input_buf[0] - (int) '0');
1463
1464 debug_flush(id, area);
1465 goto out;
1466 }
1467
1468 pr_info("Flushing debug data failed because %c is not a valid "
1469 "area\n", input_buf[0]);
1470
1471out:
1472 *offset += user_len;
1473 return rc; /* number of input characters */
1474}
1475
1476/*
1477 * prints debug data in hex/ascii format
1478 */
1479static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1480 char *out_buf, const char *in_buf)
1481{
1482 int i, rc = 0;
1483
1484 for (i = 0; i < id->buf_size; i++)
1485 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1486 rc += sprintf(out_buf + rc, "| ");
1487 for (i = 0; i < id->buf_size; i++) {
1488 unsigned char c = in_buf[i];
1489
1490 if (isascii(c) && isprint(c))
1491 rc += sprintf(out_buf + rc, "%c", c);
1492 else
1493 rc += sprintf(out_buf + rc, ".");
1494 }
1495 rc += sprintf(out_buf + rc, "\n");
1496 return rc;
1497}
1498
1499/*
1500 * prints header for debug entry
1501 */
1502int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1503 int area, debug_entry_t *entry, char *out_buf)
1504{
1505 unsigned long sec, usec;
1506 unsigned long caller;
1507 unsigned int level;
1508 char *except_str;
1509 int rc = 0;
1510
1511 level = entry->level;
1512 sec = entry->clock;
1513 usec = do_div(sec, USEC_PER_SEC);
1514
1515 if (entry->exception)
1516 except_str = "*";
1517 else
1518 except_str = "-";
1519 caller = (unsigned long) entry->caller;
1520 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %04u %px ",
1521 area, sec, usec, level, except_str,
1522 entry->cpu, (void *)caller);
1523 return rc;
1524}
1525EXPORT_SYMBOL(debug_dflt_header_fn);
1526
1527/*
1528 * prints debug data sprintf-formated:
1529 * debug_sprinf_event/exception calls must be used together with this view
1530 */
1531
1532#define DEBUG_SPRINTF_MAX_ARGS 10
1533
1534static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1535 char *out_buf, const char *inbuf)
1536{
1537 debug_sprintf_entry_t *curr_event = (debug_sprintf_entry_t *)inbuf;
1538 int num_longs, num_used_args = 0, i, rc = 0;
1539 int index[DEBUG_SPRINTF_MAX_ARGS];
1540
1541 /* count of longs fit into one entry */
1542 num_longs = id->buf_size / sizeof(long);
1543
1544 if (num_longs < 1)
1545 goto out; /* bufsize of entry too small */
1546 if (num_longs == 1) {
1547 /* no args, we use only the string */
1548 strcpy(out_buf, curr_event->string);
1549 rc = strlen(curr_event->string);
1550 goto out;
1551 }
1552
1553 /* number of arguments used for sprintf (without the format string) */
1554 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1555
1556 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1557
1558 for (i = 0; i < num_used_args; i++)
1559 index[i] = i;
1560
1561 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1562 curr_event->args[index[1]], curr_event->args[index[2]],
1563 curr_event->args[index[3]], curr_event->args[index[4]],
1564 curr_event->args[index[5]], curr_event->args[index[6]],
1565 curr_event->args[index[7]], curr_event->args[index[8]],
1566 curr_event->args[index[9]]);
1567out:
1568 return rc;
1569}
1570
1571/*
1572 * debug_init:
1573 * - is called exactly once to initialize the debug feature
1574 */
1575static int __init debug_init(void)
1576{
1577 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1578 mutex_lock(&debug_mutex);
1579 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1580 initialized = 1;
1581 mutex_unlock(&debug_mutex);
1582 return 0;
1583}
1584postcore_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);