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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[];
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
983static struct ctl_table_header *s390dbf_sysctl_header;
984
985/**
986 * debug_stop_all() - stops the debug feature if stopping is allowed.
987 *
988 * Return:
989 * - none
990 *
991 * Currently used in case of a kernel oops.
992 */
993void debug_stop_all(void)
994{
995 if (debug_stoppable)
996 debug_active = 0;
997}
998EXPORT_SYMBOL(debug_stop_all);
999
1000/**
1001 * debug_set_critical() - event/exception functions try lock instead of spin.
1002 *
1003 * Return:
1004 * - none
1005 *
1006 * Currently used in case of stopping all CPUs but the current one.
1007 * Once in this state, functions to write a debug entry for an
1008 * event or exception no longer spin on the debug area lock,
1009 * but only try to get it and fail if they do not get the lock.
1010 */
1011void debug_set_critical(void)
1012{
1013 debug_critical = 1;
1014}
1015
1016/*
1017 * debug_event_common:
1018 * - write debug entry with given size
1019 */
1020debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
1021 int len)
1022{
1023 debug_entry_t *active;
1024 unsigned long flags;
1025
1026 if (!debug_active || !id->areas)
1027 return NULL;
1028 if (debug_critical) {
1029 if (!spin_trylock_irqsave(&id->lock, flags))
1030 return NULL;
1031 } else {
1032 spin_lock_irqsave(&id->lock, flags);
1033 }
1034 do {
1035 active = get_active_entry(id);
1036 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1037 if (len < id->buf_size)
1038 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1039 debug_finish_entry(id, active, level, 0);
1040 len -= id->buf_size;
1041 buf += id->buf_size;
1042 } while (len > 0);
1043
1044 spin_unlock_irqrestore(&id->lock, flags);
1045 return active;
1046}
1047EXPORT_SYMBOL(debug_event_common);
1048
1049/*
1050 * debug_exception_common:
1051 * - write debug entry with given size and switch to next debug area
1052 */
1053debug_entry_t *debug_exception_common(debug_info_t *id, int level,
1054 const void *buf, int len)
1055{
1056 debug_entry_t *active;
1057 unsigned long flags;
1058
1059 if (!debug_active || !id->areas)
1060 return NULL;
1061 if (debug_critical) {
1062 if (!spin_trylock_irqsave(&id->lock, flags))
1063 return NULL;
1064 } else {
1065 spin_lock_irqsave(&id->lock, flags);
1066 }
1067 do {
1068 active = get_active_entry(id);
1069 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
1070 if (len < id->buf_size)
1071 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
1072 debug_finish_entry(id, active, level, len <= id->buf_size);
1073 len -= id->buf_size;
1074 buf += id->buf_size;
1075 } while (len > 0);
1076
1077 spin_unlock_irqrestore(&id->lock, flags);
1078 return active;
1079}
1080EXPORT_SYMBOL(debug_exception_common);
1081
1082/*
1083 * counts arguments in format string for sprintf view
1084 */
1085static inline int debug_count_numargs(char *string)
1086{
1087 int numargs = 0;
1088
1089 while (*string) {
1090 if (*string++ == '%')
1091 numargs++;
1092 }
1093 return numargs;
1094}
1095
1096/*
1097 * debug_sprintf_event:
1098 */
1099debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1100{
1101 debug_sprintf_entry_t *curr_event;
1102 debug_entry_t *active;
1103 unsigned long flags;
1104 int numargs, idx;
1105 va_list ap;
1106
1107 if (!debug_active || !id->areas)
1108 return NULL;
1109 numargs = debug_count_numargs(string);
1110
1111 if (debug_critical) {
1112 if (!spin_trylock_irqsave(&id->lock, flags))
1113 return NULL;
1114 } else {
1115 spin_lock_irqsave(&id->lock, flags);
1116 }
1117 active = get_active_entry(id);
1118 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1119 va_start(ap, string);
1120 curr_event->string = string;
1121 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1122 curr_event->args[idx] = va_arg(ap, long);
1123 va_end(ap);
1124 debug_finish_entry(id, active, level, 0);
1125 spin_unlock_irqrestore(&id->lock, flags);
1126
1127 return active;
1128}
1129EXPORT_SYMBOL(__debug_sprintf_event);
1130
1131/*
1132 * debug_sprintf_exception:
1133 */
1134debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1135{
1136 debug_sprintf_entry_t *curr_event;
1137 debug_entry_t *active;
1138 unsigned long flags;
1139 int numargs, idx;
1140 va_list ap;
1141
1142 if (!debug_active || !id->areas)
1143 return NULL;
1144
1145 numargs = debug_count_numargs(string);
1146
1147 if (debug_critical) {
1148 if (!spin_trylock_irqsave(&id->lock, flags))
1149 return NULL;
1150 } else {
1151 spin_lock_irqsave(&id->lock, flags);
1152 }
1153 active = get_active_entry(id);
1154 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1155 va_start(ap, string);
1156 curr_event->string = string;
1157 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1158 curr_event->args[idx] = va_arg(ap, long);
1159 va_end(ap);
1160 debug_finish_entry(id, active, level, 1);
1161 spin_unlock_irqrestore(&id->lock, flags);
1162
1163 return active;
1164}
1165EXPORT_SYMBOL(__debug_sprintf_exception);
1166
1167/**
1168 * debug_register_view() - registers new debug view and creates debugfs
1169 * dir entry
1170 *
1171 * @id: handle for debug log
1172 * @view: pointer to debug view struct
1173 *
1174 * Return:
1175 * - 0 : ok
1176 * - < 0: Error
1177 */
1178int debug_register_view(debug_info_t *id, struct debug_view *view)
1179{
1180 unsigned long flags;
1181 struct dentry *pde;
1182 umode_t mode;
1183 int rc = 0;
1184 int i;
1185
1186 if (!id)
1187 goto out;
1188 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1189 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1190 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1191 if (!view->input_proc)
1192 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1193 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1194 id, &debug_file_ops);
1195 spin_lock_irqsave(&id->lock, flags);
1196 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1197 if (!id->views[i])
1198 break;
1199 }
1200 if (i == DEBUG_MAX_VIEWS) {
1201 rc = -1;
1202 } else {
1203 id->views[i] = view;
1204 id->debugfs_entries[i] = pde;
1205 }
1206 spin_unlock_irqrestore(&id->lock, flags);
1207 if (rc) {
1208 pr_err("Registering view %s/%s would exceed the maximum "
1209 "number of views %i\n", id->name, view->name, i);
1210 debugfs_remove(pde);
1211 }
1212out:
1213 return rc;
1214}
1215EXPORT_SYMBOL(debug_register_view);
1216
1217/**
1218 * debug_unregister_view() - unregisters debug view and removes debugfs
1219 * dir entry
1220 *
1221 * @id: handle for debug log
1222 * @view: pointer to debug view struct
1223 *
1224 * Return:
1225 * - 0 : ok
1226 * - < 0: Error
1227 */
1228int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1229{
1230 struct dentry *dentry = NULL;
1231 unsigned long flags;
1232 int i, rc = 0;
1233
1234 if (!id)
1235 goto out;
1236 spin_lock_irqsave(&id->lock, flags);
1237 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1238 if (id->views[i] == view)
1239 break;
1240 }
1241 if (i == DEBUG_MAX_VIEWS) {
1242 rc = -1;
1243 } else {
1244 dentry = id->debugfs_entries[i];
1245 id->views[i] = NULL;
1246 id->debugfs_entries[i] = NULL;
1247 }
1248 spin_unlock_irqrestore(&id->lock, flags);
1249 debugfs_remove(dentry);
1250out:
1251 return rc;
1252}
1253EXPORT_SYMBOL(debug_unregister_view);
1254
1255static inline char *debug_get_user_string(const char __user *user_buf,
1256 size_t user_len)
1257{
1258 char *buffer;
1259
1260 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1261 if (!buffer)
1262 return ERR_PTR(-ENOMEM);
1263 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1264 kfree(buffer);
1265 return ERR_PTR(-EFAULT);
1266 }
1267 /* got the string, now strip linefeed. */
1268 if (buffer[user_len - 1] == '\n')
1269 buffer[user_len - 1] = 0;
1270 else
1271 buffer[user_len] = 0;
1272 return buffer;
1273}
1274
1275static inline int debug_get_uint(char *buf)
1276{
1277 int rc;
1278
1279 buf = skip_spaces(buf);
1280 rc = simple_strtoul(buf, &buf, 10);
1281 if (*buf)
1282 rc = -EINVAL;
1283 return rc;
1284}
1285
1286/*
1287 * functions for debug-views
1288 ***********************************
1289*/
1290
1291/*
1292 * prints out actual debug level
1293 */
1294
1295static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1296 char *out_buf)
1297{
1298 return sprintf(out_buf, "%i\n", id->pages_per_area);
1299}
1300
1301/*
1302 * reads new size (number of pages per debug area)
1303 */
1304
1305static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1306 struct file *file, const char __user *user_buf,
1307 size_t user_len, loff_t *offset)
1308{
1309 int rc, new_pages;
1310 char *str;
1311
1312 if (user_len > 0x10000)
1313 user_len = 0x10000;
1314 if (*offset != 0) {
1315 rc = -EPIPE;
1316 goto out;
1317 }
1318 str = debug_get_user_string(user_buf, user_len);
1319 if (IS_ERR(str)) {
1320 rc = PTR_ERR(str);
1321 goto out;
1322 }
1323 new_pages = debug_get_uint(str);
1324 if (new_pages < 0) {
1325 rc = -EINVAL;
1326 goto free_str;
1327 }
1328 rc = debug_set_size(id, id->nr_areas, new_pages);
1329 if (rc != 0) {
1330 rc = -EINVAL;
1331 goto free_str;
1332 }
1333 rc = user_len;
1334free_str:
1335 kfree(str);
1336out:
1337 *offset += user_len;
1338 return rc; /* number of input characters */
1339}
1340
1341/*
1342 * prints out actual debug level
1343 */
1344static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1345 char *out_buf)
1346{
1347 int rc = 0;
1348
1349 if (id->level == DEBUG_OFF_LEVEL)
1350 rc = sprintf(out_buf, "-\n");
1351 else
1352 rc = sprintf(out_buf, "%i\n", id->level);
1353 return rc;
1354}
1355
1356/*
1357 * reads new debug level
1358 */
1359static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1360 struct file *file, const char __user *user_buf,
1361 size_t user_len, loff_t *offset)
1362{
1363 int rc, new_level;
1364 char *str;
1365
1366 if (user_len > 0x10000)
1367 user_len = 0x10000;
1368 if (*offset != 0) {
1369 rc = -EPIPE;
1370 goto out;
1371 }
1372 str = debug_get_user_string(user_buf, user_len);
1373 if (IS_ERR(str)) {
1374 rc = PTR_ERR(str);
1375 goto out;
1376 }
1377 if (str[0] == '-') {
1378 debug_set_level(id, DEBUG_OFF_LEVEL);
1379 rc = user_len;
1380 goto free_str;
1381 } else {
1382 new_level = debug_get_uint(str);
1383 }
1384 if (new_level < 0) {
1385 pr_warn("%s is not a valid level for a debug feature\n", str);
1386 rc = -EINVAL;
1387 } else {
1388 debug_set_level(id, new_level);
1389 rc = user_len;
1390 }
1391free_str:
1392 kfree(str);
1393out:
1394 *offset += user_len;
1395 return rc; /* number of input characters */
1396}
1397
1398/*
1399 * flushes debug areas
1400 */
1401static void debug_flush(debug_info_t *id, int area)
1402{
1403 unsigned long flags;
1404 int i, j;
1405
1406 if (!id || !id->areas)
1407 return;
1408 spin_lock_irqsave(&id->lock, flags);
1409 if (area == DEBUG_FLUSH_ALL) {
1410 id->active_area = 0;
1411 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1412 for (i = 0; i < id->nr_areas; i++) {
1413 id->active_pages[i] = 0;
1414 for (j = 0; j < id->pages_per_area; j++)
1415 memset(id->areas[i][j], 0, PAGE_SIZE);
1416 }
1417 } else if (area >= 0 && area < id->nr_areas) {
1418 id->active_entries[area] = 0;
1419 id->active_pages[area] = 0;
1420 for (i = 0; i < id->pages_per_area; i++)
1421 memset(id->areas[area][i], 0, PAGE_SIZE);
1422 }
1423 spin_unlock_irqrestore(&id->lock, flags);
1424}
1425
1426/*
1427 * view function: flushes debug areas
1428 */
1429static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1430 struct file *file, const char __user *user_buf,
1431 size_t user_len, loff_t *offset)
1432{
1433 char input_buf[1];
1434 int rc = user_len;
1435
1436 if (user_len > 0x10000)
1437 user_len = 0x10000;
1438 if (*offset != 0) {
1439 rc = -EPIPE;
1440 goto out;
1441 }
1442 if (copy_from_user(input_buf, user_buf, 1)) {
1443 rc = -EFAULT;
1444 goto out;
1445 }
1446 if (input_buf[0] == '-') {
1447 debug_flush(id, DEBUG_FLUSH_ALL);
1448 goto out;
1449 }
1450 if (isdigit(input_buf[0])) {
1451 int area = ((int) input_buf[0] - (int) '0');
1452
1453 debug_flush(id, area);
1454 goto out;
1455 }
1456
1457 pr_info("Flushing debug data failed because %c is not a valid "
1458 "area\n", input_buf[0]);
1459
1460out:
1461 *offset += user_len;
1462 return rc; /* number of input characters */
1463}
1464
1465/*
1466 * prints debug data in hex/ascii format
1467 */
1468static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1469 char *out_buf, const char *in_buf)
1470{
1471 int i, rc = 0;
1472
1473 for (i = 0; i < id->buf_size; i++)
1474 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1475 rc += sprintf(out_buf + rc, "| ");
1476 for (i = 0; i < id->buf_size; i++) {
1477 unsigned char c = in_buf[i];
1478
1479 if (isascii(c) && isprint(c))
1480 rc += sprintf(out_buf + rc, "%c", c);
1481 else
1482 rc += sprintf(out_buf + rc, ".");
1483 }
1484 rc += sprintf(out_buf + rc, "\n");
1485 return rc;
1486}
1487
1488/*
1489 * prints header for debug entry
1490 */
1491int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1492 int area, debug_entry_t *entry, char *out_buf)
1493{
1494 unsigned long sec, usec;
1495 unsigned long caller;
1496 unsigned int level;
1497 char *except_str;
1498 int rc = 0;
1499
1500 level = entry->level;
1501 sec = entry->clock;
1502 usec = do_div(sec, USEC_PER_SEC);
1503
1504 if (entry->exception)
1505 except_str = "*";
1506 else
1507 except_str = "-";
1508 caller = (unsigned long) entry->caller;
1509 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %04u %px ",
1510 area, sec, usec, level, except_str,
1511 entry->cpu, (void *)caller);
1512 return rc;
1513}
1514EXPORT_SYMBOL(debug_dflt_header_fn);
1515
1516/*
1517 * prints debug data sprintf-formated:
1518 * debug_sprinf_event/exception calls must be used together with this view
1519 */
1520
1521#define DEBUG_SPRINTF_MAX_ARGS 10
1522
1523static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1524 char *out_buf, const char *inbuf)
1525{
1526 debug_sprintf_entry_t *curr_event = (debug_sprintf_entry_t *)inbuf;
1527 int num_longs, num_used_args = 0, i, rc = 0;
1528 int index[DEBUG_SPRINTF_MAX_ARGS];
1529
1530 /* count of longs fit into one entry */
1531 num_longs = id->buf_size / sizeof(long);
1532
1533 if (num_longs < 1)
1534 goto out; /* bufsize of entry too small */
1535 if (num_longs == 1) {
1536 /* no args, we use only the string */
1537 strcpy(out_buf, curr_event->string);
1538 rc = strlen(curr_event->string);
1539 goto out;
1540 }
1541
1542 /* number of arguments used for sprintf (without the format string) */
1543 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1544
1545 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1546
1547 for (i = 0; i < num_used_args; i++)
1548 index[i] = i;
1549
1550 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1551 curr_event->args[index[1]], curr_event->args[index[2]],
1552 curr_event->args[index[3]], curr_event->args[index[4]],
1553 curr_event->args[index[5]], curr_event->args[index[6]],
1554 curr_event->args[index[7]], curr_event->args[index[8]],
1555 curr_event->args[index[9]]);
1556out:
1557 return rc;
1558}
1559
1560/*
1561 * debug_init:
1562 * - is called exactly once to initialize the debug feature
1563 */
1564static int __init debug_init(void)
1565{
1566 s390dbf_sysctl_header = register_sysctl("s390dbf", s390dbf_table);
1567 mutex_lock(&debug_mutex);
1568 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1569 initialized = 1;
1570 mutex_unlock(&debug_mutex);
1571 return 0;
1572}
1573postcore_initcall(debug_init);
1/*
2 * arch/s390/kernel/debug.c
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2012
6 *
7 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
8 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
9 *
10 * Bugreports to: <Linux390@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "s390dbf"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/ctype.h>
21#include <linux/string.h>
22#include <linux/sysctl.h>
23#include <asm/uaccess.h>
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/debugfs.h>
28
29#include <asm/debug.h>
30
31#define DEBUG_PROLOG_ENTRY -1
32
33#define ALL_AREAS 0 /* copy all debug areas */
34#define NO_AREAS 1 /* copy no debug areas */
35
36/* typedefs */
37
38typedef struct file_private_info {
39 loff_t offset; /* offset of last read in file */
40 int act_area; /* number of last formated area */
41 int act_page; /* act page in given area */
42 int act_entry; /* last formated entry (offset */
43 /* relative to beginning of last */
44 /* formated page) */
45 size_t act_entry_offset; /* up to this offset we copied */
46 /* in last read the last formated */
47 /* entry to userland */
48 char temp_buf[2048]; /* buffer for output */
49 debug_info_t *debug_info_org; /* original debug information */
50 debug_info_t *debug_info_snap; /* snapshot of debug information */
51 struct debug_view *view; /* used view of debug info */
52} file_private_info_t;
53
54typedef struct
55{
56 char *string;
57 /*
58 * This assumes that all args are converted into longs
59 * on L/390 this is the case for all types of parameter
60 * except of floats, and long long (32 bit)
61 *
62 */
63 long args[0];
64} debug_sprintf_entry_t;
65
66
67/* internal function prototyes */
68
69static int debug_init(void);
70static ssize_t debug_output(struct file *file, char __user *user_buf,
71 size_t user_len, loff_t * offset);
72static ssize_t debug_input(struct file *file, const char __user *user_buf,
73 size_t user_len, loff_t * offset);
74static int debug_open(struct inode *inode, struct file *file);
75static int debug_close(struct inode *inode, struct file *file);
76static debug_info_t *debug_info_create(const char *name, int pages_per_area,
77 int nr_areas, int buf_size, umode_t mode);
78static void debug_info_get(debug_info_t *);
79static void debug_info_put(debug_info_t *);
80static int debug_prolog_level_fn(debug_info_t * id,
81 struct debug_view *view, char *out_buf);
82static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
83 struct file *file, const char __user *user_buf,
84 size_t user_buf_size, loff_t * offset);
85static int debug_prolog_pages_fn(debug_info_t * id,
86 struct debug_view *view, char *out_buf);
87static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
88 struct file *file, const char __user *user_buf,
89 size_t user_buf_size, loff_t * offset);
90static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
91 struct file *file, const char __user *user_buf,
92 size_t user_buf_size, loff_t * offset);
93static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
94 char *out_buf, const char *in_buf);
95static int debug_raw_format_fn(debug_info_t * id,
96 struct debug_view *view, char *out_buf,
97 const char *in_buf);
98static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
99 int area, debug_entry_t * entry, char *out_buf);
100
101static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
102 char *out_buf, debug_sprintf_entry_t *curr_event);
103
104/* globals */
105
106struct debug_view debug_raw_view = {
107 "raw",
108 NULL,
109 &debug_raw_header_fn,
110 &debug_raw_format_fn,
111 NULL,
112 NULL
113};
114
115struct debug_view debug_hex_ascii_view = {
116 "hex_ascii",
117 NULL,
118 &debug_dflt_header_fn,
119 &debug_hex_ascii_format_fn,
120 NULL,
121 NULL
122};
123
124static struct debug_view debug_level_view = {
125 "level",
126 &debug_prolog_level_fn,
127 NULL,
128 NULL,
129 &debug_input_level_fn,
130 NULL
131};
132
133static struct debug_view debug_pages_view = {
134 "pages",
135 &debug_prolog_pages_fn,
136 NULL,
137 NULL,
138 &debug_input_pages_fn,
139 NULL
140};
141
142static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149};
150
151struct debug_view debug_sprintf_view = {
152 "sprintf",
153 NULL,
154 &debug_dflt_header_fn,
155 (debug_format_proc_t*)&debug_sprintf_format_fn,
156 NULL,
157 NULL
158};
159
160/* used by dump analysis tools to determine version of debug feature */
161static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
162
163/* static globals */
164
165static debug_info_t *debug_area_first = NULL;
166static debug_info_t *debug_area_last = NULL;
167static DEFINE_MUTEX(debug_mutex);
168
169static int initialized;
170static int debug_critical;
171
172static const struct file_operations debug_file_ops = {
173 .owner = THIS_MODULE,
174 .read = debug_output,
175 .write = debug_input,
176 .open = debug_open,
177 .release = debug_close,
178 .llseek = no_llseek,
179};
180
181static struct dentry *debug_debugfs_root_entry;
182
183/* functions */
184
185/*
186 * debug_areas_alloc
187 * - Debug areas are implemented as a threedimensonal array:
188 * areas[areanumber][pagenumber][pageoffset]
189 */
190
191static debug_entry_t***
192debug_areas_alloc(int pages_per_area, int nr_areas)
193{
194 debug_entry_t*** areas;
195 int i,j;
196
197 areas = kmalloc(nr_areas *
198 sizeof(debug_entry_t**),
199 GFP_KERNEL);
200 if (!areas)
201 goto fail_malloc_areas;
202 for (i = 0; i < nr_areas; i++) {
203 areas[i] = kmalloc(pages_per_area *
204 sizeof(debug_entry_t*),GFP_KERNEL);
205 if (!areas[i]) {
206 goto fail_malloc_areas2;
207 }
208 for(j = 0; j < pages_per_area; j++) {
209 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
210 if(!areas[i][j]) {
211 for(j--; j >=0 ; j--) {
212 kfree(areas[i][j]);
213 }
214 kfree(areas[i]);
215 goto fail_malloc_areas2;
216 }
217 }
218 }
219 return areas;
220
221fail_malloc_areas2:
222 for(i--; i >= 0; i--){
223 for(j=0; j < pages_per_area;j++){
224 kfree(areas[i][j]);
225 }
226 kfree(areas[i]);
227 }
228 kfree(areas);
229fail_malloc_areas:
230 return NULL;
231
232}
233
234
235/*
236 * debug_info_alloc
237 * - alloc new debug-info
238 */
239
240static debug_info_t*
241debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
242 int buf_size, int level, int mode)
243{
244 debug_info_t* rc;
245
246 /* alloc everything */
247
248 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
249 if(!rc)
250 goto fail_malloc_rc;
251 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
252 if(!rc->active_entries)
253 goto fail_malloc_active_entries;
254 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
255 if(!rc->active_pages)
256 goto fail_malloc_active_pages;
257 if((mode == ALL_AREAS) && (pages_per_area != 0)){
258 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
259 if(!rc->areas)
260 goto fail_malloc_areas;
261 } else {
262 rc->areas = NULL;
263 }
264
265 /* initialize members */
266
267 spin_lock_init(&rc->lock);
268 rc->pages_per_area = pages_per_area;
269 rc->nr_areas = nr_areas;
270 rc->active_area = 0;
271 rc->level = level;
272 rc->buf_size = buf_size;
273 rc->entry_size = sizeof(debug_entry_t) + buf_size;
274 strlcpy(rc->name, name, sizeof(rc->name));
275 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
276 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
277 sizeof(struct dentry*));
278 atomic_set(&(rc->ref_count), 0);
279
280 return rc;
281
282fail_malloc_areas:
283 kfree(rc->active_pages);
284fail_malloc_active_pages:
285 kfree(rc->active_entries);
286fail_malloc_active_entries:
287 kfree(rc);
288fail_malloc_rc:
289 return NULL;
290}
291
292/*
293 * debug_areas_free
294 * - free all debug areas
295 */
296
297static void
298debug_areas_free(debug_info_t* db_info)
299{
300 int i,j;
301
302 if(!db_info->areas)
303 return;
304 for (i = 0; i < db_info->nr_areas; i++) {
305 for(j = 0; j < db_info->pages_per_area; j++) {
306 kfree(db_info->areas[i][j]);
307 }
308 kfree(db_info->areas[i]);
309 }
310 kfree(db_info->areas);
311 db_info->areas = NULL;
312}
313
314/*
315 * debug_info_free
316 * - free memory debug-info
317 */
318
319static void
320debug_info_free(debug_info_t* db_info){
321 debug_areas_free(db_info);
322 kfree(db_info->active_entries);
323 kfree(db_info->active_pages);
324 kfree(db_info);
325}
326
327/*
328 * debug_info_create
329 * - create new debug-info
330 */
331
332static debug_info_t*
333debug_info_create(const char *name, int pages_per_area, int nr_areas,
334 int buf_size, umode_t mode)
335{
336 debug_info_t* rc;
337
338 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
339 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
340 if(!rc)
341 goto out;
342
343 rc->mode = mode & ~S_IFMT;
344
345 /* create root directory */
346 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
347 debug_debugfs_root_entry);
348
349 /* append new element to linked list */
350 if (!debug_area_first) {
351 /* first element in list */
352 debug_area_first = rc;
353 rc->prev = NULL;
354 } else {
355 /* append element to end of list */
356 debug_area_last->next = rc;
357 rc->prev = debug_area_last;
358 }
359 debug_area_last = rc;
360 rc->next = NULL;
361
362 debug_info_get(rc);
363out:
364 return rc;
365}
366
367/*
368 * debug_info_copy
369 * - copy debug-info
370 */
371
372static debug_info_t*
373debug_info_copy(debug_info_t* in, int mode)
374{
375 int i,j;
376 debug_info_t* rc;
377 unsigned long flags;
378
379 /* get a consistent copy of the debug areas */
380 do {
381 rc = debug_info_alloc(in->name, in->pages_per_area,
382 in->nr_areas, in->buf_size, in->level, mode);
383 spin_lock_irqsave(&in->lock, flags);
384 if(!rc)
385 goto out;
386 /* has something changed in the meantime ? */
387 if((rc->pages_per_area == in->pages_per_area) &&
388 (rc->nr_areas == in->nr_areas)) {
389 break;
390 }
391 spin_unlock_irqrestore(&in->lock, flags);
392 debug_info_free(rc);
393 } while (1);
394
395 if (mode == NO_AREAS)
396 goto out;
397
398 for(i = 0; i < in->nr_areas; i++){
399 for(j = 0; j < in->pages_per_area; j++) {
400 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
401 }
402 }
403out:
404 spin_unlock_irqrestore(&in->lock, flags);
405 return rc;
406}
407
408/*
409 * debug_info_get
410 * - increments reference count for debug-info
411 */
412
413static void
414debug_info_get(debug_info_t * db_info)
415{
416 if (db_info)
417 atomic_inc(&db_info->ref_count);
418}
419
420/*
421 * debug_info_put:
422 * - decreases reference count for debug-info and frees it if necessary
423 */
424
425static void
426debug_info_put(debug_info_t *db_info)
427{
428 int i;
429
430 if (!db_info)
431 return;
432 if (atomic_dec_and_test(&db_info->ref_count)) {
433 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
434 if (!db_info->views[i])
435 continue;
436 debugfs_remove(db_info->debugfs_entries[i]);
437 }
438 debugfs_remove(db_info->debugfs_root_entry);
439 if(db_info == debug_area_first)
440 debug_area_first = db_info->next;
441 if(db_info == debug_area_last)
442 debug_area_last = db_info->prev;
443 if(db_info->prev) db_info->prev->next = db_info->next;
444 if(db_info->next) db_info->next->prev = db_info->prev;
445 debug_info_free(db_info);
446 }
447}
448
449/*
450 * debug_format_entry:
451 * - format one debug entry and return size of formated data
452 */
453
454static int
455debug_format_entry(file_private_info_t *p_info)
456{
457 debug_info_t *id_snap = p_info->debug_info_snap;
458 struct debug_view *view = p_info->view;
459 debug_entry_t *act_entry;
460 size_t len = 0;
461 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
462 /* print prolog */
463 if (view->prolog_proc)
464 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
465 goto out;
466 }
467 if (!id_snap->areas) /* this is true, if we have a prolog only view */
468 goto out; /* or if 'pages_per_area' is 0 */
469 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
470 [p_info->act_page] + p_info->act_entry);
471
472 if (act_entry->id.stck == 0LL)
473 goto out; /* empty entry */
474 if (view->header_proc)
475 len += view->header_proc(id_snap, view, p_info->act_area,
476 act_entry, p_info->temp_buf + len);
477 if (view->format_proc)
478 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
479 DEBUG_DATA(act_entry));
480out:
481 return len;
482}
483
484/*
485 * debug_next_entry:
486 * - goto next entry in p_info
487 */
488
489static inline int
490debug_next_entry(file_private_info_t *p_info)
491{
492 debug_info_t *id;
493
494 id = p_info->debug_info_snap;
495 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
496 p_info->act_entry = 0;
497 p_info->act_page = 0;
498 goto out;
499 }
500 if(!id->areas)
501 return 1;
502 p_info->act_entry += id->entry_size;
503 /* switch to next page, if we reached the end of the page */
504 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
505 /* next page */
506 p_info->act_entry = 0;
507 p_info->act_page += 1;
508 if((p_info->act_page % id->pages_per_area) == 0) {
509 /* next area */
510 p_info->act_area++;
511 p_info->act_page=0;
512 }
513 if(p_info->act_area >= id->nr_areas)
514 return 1;
515 }
516out:
517 return 0;
518}
519
520/*
521 * debug_output:
522 * - called for user read()
523 * - copies formated debug entries to the user buffer
524 */
525
526static ssize_t
527debug_output(struct file *file, /* file descriptor */
528 char __user *user_buf, /* user buffer */
529 size_t len, /* length of buffer */
530 loff_t *offset) /* offset in the file */
531{
532 size_t count = 0;
533 size_t entry_offset;
534 file_private_info_t *p_info;
535
536 p_info = ((file_private_info_t *) file->private_data);
537 if (*offset != p_info->offset)
538 return -EPIPE;
539 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
540 return 0;
541 entry_offset = p_info->act_entry_offset;
542 while(count < len){
543 int formatted_line_size;
544 int formatted_line_residue;
545 int user_buf_residue;
546 size_t copy_size;
547
548 formatted_line_size = debug_format_entry(p_info);
549 formatted_line_residue = formatted_line_size - entry_offset;
550 user_buf_residue = len-count;
551 copy_size = min(user_buf_residue, formatted_line_residue);
552 if(copy_size){
553 if (copy_to_user(user_buf + count, p_info->temp_buf
554 + entry_offset, copy_size))
555 return -EFAULT;
556 count += copy_size;
557 entry_offset += copy_size;
558 }
559 if(copy_size == formatted_line_residue){
560 entry_offset = 0;
561 if(debug_next_entry(p_info))
562 goto out;
563 }
564 }
565out:
566 p_info->offset = *offset + count;
567 p_info->act_entry_offset = entry_offset;
568 *offset = p_info->offset;
569 return count;
570}
571
572/*
573 * debug_input:
574 * - called for user write()
575 * - calls input function of view
576 */
577
578static ssize_t
579debug_input(struct file *file, const char __user *user_buf, size_t length,
580 loff_t *offset)
581{
582 int rc = 0;
583 file_private_info_t *p_info;
584
585 mutex_lock(&debug_mutex);
586 p_info = ((file_private_info_t *) file->private_data);
587 if (p_info->view->input_proc)
588 rc = p_info->view->input_proc(p_info->debug_info_org,
589 p_info->view, file, user_buf,
590 length, offset);
591 else
592 rc = -EPERM;
593 mutex_unlock(&debug_mutex);
594 return rc; /* number of input characters */
595}
596
597/*
598 * debug_open:
599 * - called for user open()
600 * - copies formated output to private_data area of the file
601 * handle
602 */
603
604static int
605debug_open(struct inode *inode, struct file *file)
606{
607 int i, rc = 0;
608 file_private_info_t *p_info;
609 debug_info_t *debug_info, *debug_info_snapshot;
610
611 mutex_lock(&debug_mutex);
612 debug_info = file->f_path.dentry->d_inode->i_private;
613 /* find debug view */
614 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
615 if (!debug_info->views[i])
616 continue;
617 else if (debug_info->debugfs_entries[i] ==
618 file->f_path.dentry) {
619 goto found; /* found view ! */
620 }
621 }
622 /* no entry found */
623 rc = -EINVAL;
624 goto out;
625
626found:
627
628 /* Make snapshot of current debug areas to get it consistent. */
629 /* To copy all the areas is only needed, if we have a view which */
630 /* formats the debug areas. */
631
632 if(!debug_info->views[i]->format_proc &&
633 !debug_info->views[i]->header_proc){
634 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
635 } else {
636 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
637 }
638
639 if(!debug_info_snapshot){
640 rc = -ENOMEM;
641 goto out;
642 }
643 p_info = kmalloc(sizeof(file_private_info_t),
644 GFP_KERNEL);
645 if(!p_info){
646 debug_info_free(debug_info_snapshot);
647 rc = -ENOMEM;
648 goto out;
649 }
650 p_info->offset = 0;
651 p_info->debug_info_snap = debug_info_snapshot;
652 p_info->debug_info_org = debug_info;
653 p_info->view = debug_info->views[i];
654 p_info->act_area = 0;
655 p_info->act_page = 0;
656 p_info->act_entry = DEBUG_PROLOG_ENTRY;
657 p_info->act_entry_offset = 0;
658 file->private_data = p_info;
659 debug_info_get(debug_info);
660 nonseekable_open(inode, file);
661out:
662 mutex_unlock(&debug_mutex);
663 return rc;
664}
665
666/*
667 * debug_close:
668 * - called for user close()
669 * - deletes private_data area of the file handle
670 */
671
672static int
673debug_close(struct inode *inode, struct file *file)
674{
675 file_private_info_t *p_info;
676 p_info = (file_private_info_t *) file->private_data;
677 if(p_info->debug_info_snap)
678 debug_info_free(p_info->debug_info_snap);
679 debug_info_put(p_info->debug_info_org);
680 kfree(file->private_data);
681 return 0; /* success */
682}
683
684/*
685 * debug_register_mode:
686 * - Creates and initializes debug area for the caller
687 * The mode parameter allows to specify access rights for the s390dbf files
688 * - Returns handle for debug area
689 */
690
691debug_info_t *debug_register_mode(const char *name, int pages_per_area,
692 int nr_areas, int buf_size, umode_t mode,
693 uid_t uid, gid_t gid)
694{
695 debug_info_t *rc = NULL;
696
697 /* Since debugfs currently does not support uid/gid other than root, */
698 /* we do not allow gid/uid != 0 until we get support for that. */
699 if ((uid != 0) || (gid != 0))
700 pr_warning("Root becomes the owner of all s390dbf files "
701 "in sysfs\n");
702 BUG_ON(!initialized);
703 mutex_lock(&debug_mutex);
704
705 /* create new debug_info */
706
707 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
708 if(!rc)
709 goto out;
710 debug_register_view(rc, &debug_level_view);
711 debug_register_view(rc, &debug_flush_view);
712 debug_register_view(rc, &debug_pages_view);
713out:
714 if (!rc){
715 pr_err("Registering debug feature %s failed\n", name);
716 }
717 mutex_unlock(&debug_mutex);
718 return rc;
719}
720EXPORT_SYMBOL(debug_register_mode);
721
722/*
723 * debug_register:
724 * - creates and initializes debug area for the caller
725 * - returns handle for debug area
726 */
727
728debug_info_t *debug_register(const char *name, int pages_per_area,
729 int nr_areas, int buf_size)
730{
731 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
732 S_IRUSR | S_IWUSR, 0, 0);
733}
734
735/*
736 * debug_unregister:
737 * - give back debug area
738 */
739
740void
741debug_unregister(debug_info_t * id)
742{
743 if (!id)
744 goto out;
745 mutex_lock(&debug_mutex);
746 debug_info_put(id);
747 mutex_unlock(&debug_mutex);
748
749out:
750 return;
751}
752
753/*
754 * debug_set_size:
755 * - set area size (number of pages) and number of areas
756 */
757static int
758debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
759{
760 unsigned long flags;
761 debug_entry_t *** new_areas;
762 int rc=0;
763
764 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
765 return -EINVAL;
766 if(pages_per_area > 0){
767 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
768 if(!new_areas) {
769 pr_info("Allocating memory for %i pages failed\n",
770 pages_per_area);
771 rc = -ENOMEM;
772 goto out;
773 }
774 } else {
775 new_areas = NULL;
776 }
777 spin_lock_irqsave(&id->lock,flags);
778 debug_areas_free(id);
779 id->areas = new_areas;
780 id->nr_areas = nr_areas;
781 id->pages_per_area = pages_per_area;
782 id->active_area = 0;
783 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
784 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
785 spin_unlock_irqrestore(&id->lock,flags);
786 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
787out:
788 return rc;
789}
790
791/*
792 * debug_set_level:
793 * - set actual debug level
794 */
795
796void
797debug_set_level(debug_info_t* id, int new_level)
798{
799 unsigned long flags;
800 if(!id)
801 return;
802 spin_lock_irqsave(&id->lock,flags);
803 if(new_level == DEBUG_OFF_LEVEL){
804 id->level = DEBUG_OFF_LEVEL;
805 pr_info("%s: switched off\n",id->name);
806 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
807 pr_info("%s: level %i is out of range (%i - %i)\n",
808 id->name, new_level, 0, DEBUG_MAX_LEVEL);
809 } else {
810 id->level = new_level;
811 }
812 spin_unlock_irqrestore(&id->lock,flags);
813}
814
815
816/*
817 * proceed_active_entry:
818 * - set active entry to next in the ring buffer
819 */
820
821static inline void
822proceed_active_entry(debug_info_t * id)
823{
824 if ((id->active_entries[id->active_area] += id->entry_size)
825 > (PAGE_SIZE - id->entry_size)){
826 id->active_entries[id->active_area] = 0;
827 id->active_pages[id->active_area] =
828 (id->active_pages[id->active_area] + 1) %
829 id->pages_per_area;
830 }
831}
832
833/*
834 * proceed_active_area:
835 * - set active area to next in the ring buffer
836 */
837
838static inline void
839proceed_active_area(debug_info_t * id)
840{
841 id->active_area++;
842 id->active_area = id->active_area % id->nr_areas;
843}
844
845/*
846 * get_active_entry:
847 */
848
849static inline debug_entry_t*
850get_active_entry(debug_info_t * id)
851{
852 return (debug_entry_t *) (((char *) id->areas[id->active_area]
853 [id->active_pages[id->active_area]]) +
854 id->active_entries[id->active_area]);
855}
856
857/*
858 * debug_finish_entry:
859 * - set timestamp, caller address, cpu number etc.
860 */
861
862static inline void
863debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
864 int exception)
865{
866 active->id.stck = get_clock();
867 active->id.fields.cpuid = smp_processor_id();
868 active->caller = __builtin_return_address(0);
869 active->id.fields.exception = exception;
870 active->id.fields.level = level;
871 proceed_active_entry(id);
872 if(exception)
873 proceed_active_area(id);
874}
875
876static int debug_stoppable=1;
877static int debug_active=1;
878
879#define CTL_S390DBF_STOPPABLE 5678
880#define CTL_S390DBF_ACTIVE 5679
881
882/*
883 * proc handler for the running debug_active sysctl
884 * always allow read, allow write only if debug_stoppable is set or
885 * if debug_active is already off
886 */
887static int
888s390dbf_procactive(ctl_table *table, int write,
889 void __user *buffer, size_t *lenp, loff_t *ppos)
890{
891 if (!write || debug_stoppable || !debug_active)
892 return proc_dointvec(table, write, buffer, lenp, ppos);
893 else
894 return 0;
895}
896
897
898static struct ctl_table s390dbf_table[] = {
899 {
900 .procname = "debug_stoppable",
901 .data = &debug_stoppable,
902 .maxlen = sizeof(int),
903 .mode = S_IRUGO | S_IWUSR,
904 .proc_handler = proc_dointvec,
905 },
906 {
907 .procname = "debug_active",
908 .data = &debug_active,
909 .maxlen = sizeof(int),
910 .mode = S_IRUGO | S_IWUSR,
911 .proc_handler = s390dbf_procactive,
912 },
913 { }
914};
915
916static struct ctl_table s390dbf_dir_table[] = {
917 {
918 .procname = "s390dbf",
919 .maxlen = 0,
920 .mode = S_IRUGO | S_IXUGO,
921 .child = s390dbf_table,
922 },
923 { }
924};
925
926static struct ctl_table_header *s390dbf_sysctl_header;
927
928void
929debug_stop_all(void)
930{
931 if (debug_stoppable)
932 debug_active = 0;
933}
934
935
936void debug_set_critical(void)
937{
938 debug_critical = 1;
939}
940
941/*
942 * debug_event_common:
943 * - write debug entry with given size
944 */
945
946debug_entry_t*
947debug_event_common(debug_info_t * id, int level, const void *buf, int len)
948{
949 unsigned long flags;
950 debug_entry_t *active;
951
952 if (!debug_active || !id->areas)
953 return NULL;
954 if (debug_critical) {
955 if (!spin_trylock_irqsave(&id->lock, flags))
956 return NULL;
957 } else
958 spin_lock_irqsave(&id->lock, flags);
959 active = get_active_entry(id);
960 memset(DEBUG_DATA(active), 0, id->buf_size);
961 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
962 debug_finish_entry(id, active, level, 0);
963 spin_unlock_irqrestore(&id->lock, flags);
964
965 return active;
966}
967
968/*
969 * debug_exception_common:
970 * - write debug entry with given size and switch to next debug area
971 */
972
973debug_entry_t
974*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
975{
976 unsigned long flags;
977 debug_entry_t *active;
978
979 if (!debug_active || !id->areas)
980 return NULL;
981 if (debug_critical) {
982 if (!spin_trylock_irqsave(&id->lock, flags))
983 return NULL;
984 } else
985 spin_lock_irqsave(&id->lock, flags);
986 active = get_active_entry(id);
987 memset(DEBUG_DATA(active), 0, id->buf_size);
988 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
989 debug_finish_entry(id, active, level, 1);
990 spin_unlock_irqrestore(&id->lock, flags);
991
992 return active;
993}
994
995/*
996 * counts arguments in format string for sprintf view
997 */
998
999static inline int
1000debug_count_numargs(char *string)
1001{
1002 int numargs=0;
1003
1004 while(*string) {
1005 if(*string++=='%')
1006 numargs++;
1007 }
1008 return(numargs);
1009}
1010
1011/*
1012 * debug_sprintf_event:
1013 */
1014
1015debug_entry_t*
1016debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1017{
1018 va_list ap;
1019 int numargs,idx;
1020 unsigned long flags;
1021 debug_sprintf_entry_t *curr_event;
1022 debug_entry_t *active;
1023
1024 if((!id) || (level > id->level))
1025 return NULL;
1026 if (!debug_active || !id->areas)
1027 return NULL;
1028 numargs=debug_count_numargs(string);
1029
1030 if (debug_critical) {
1031 if (!spin_trylock_irqsave(&id->lock, flags))
1032 return NULL;
1033 } else
1034 spin_lock_irqsave(&id->lock, flags);
1035 active = get_active_entry(id);
1036 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1037 va_start(ap,string);
1038 curr_event->string=string;
1039 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1040 curr_event->args[idx]=va_arg(ap,long);
1041 va_end(ap);
1042 debug_finish_entry(id, active, level, 0);
1043 spin_unlock_irqrestore(&id->lock, flags);
1044
1045 return active;
1046}
1047
1048/*
1049 * debug_sprintf_exception:
1050 */
1051
1052debug_entry_t*
1053debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1054{
1055 va_list ap;
1056 int numargs,idx;
1057 unsigned long flags;
1058 debug_sprintf_entry_t *curr_event;
1059 debug_entry_t *active;
1060
1061 if((!id) || (level > id->level))
1062 return NULL;
1063 if (!debug_active || !id->areas)
1064 return NULL;
1065
1066 numargs=debug_count_numargs(string);
1067
1068 if (debug_critical) {
1069 if (!spin_trylock_irqsave(&id->lock, flags))
1070 return NULL;
1071 } else
1072 spin_lock_irqsave(&id->lock, flags);
1073 active = get_active_entry(id);
1074 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1075 va_start(ap,string);
1076 curr_event->string=string;
1077 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1078 curr_event->args[idx]=va_arg(ap,long);
1079 va_end(ap);
1080 debug_finish_entry(id, active, level, 1);
1081 spin_unlock_irqrestore(&id->lock, flags);
1082
1083 return active;
1084}
1085
1086/*
1087 * debug_init:
1088 * - is called exactly once to initialize the debug feature
1089 */
1090
1091static int
1092__init debug_init(void)
1093{
1094 int rc = 0;
1095
1096 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1097 mutex_lock(&debug_mutex);
1098 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1099 initialized = 1;
1100 mutex_unlock(&debug_mutex);
1101
1102 return rc;
1103}
1104
1105/*
1106 * debug_register_view:
1107 */
1108
1109int
1110debug_register_view(debug_info_t * id, struct debug_view *view)
1111{
1112 int rc = 0;
1113 int i;
1114 unsigned long flags;
1115 umode_t mode;
1116 struct dentry *pde;
1117
1118 if (!id)
1119 goto out;
1120 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1121 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1122 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1123 if (!view->input_proc)
1124 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1125 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1126 id , &debug_file_ops);
1127 if (!pde){
1128 pr_err("Registering view %s/%s failed due to out of "
1129 "memory\n", id->name,view->name);
1130 rc = -1;
1131 goto out;
1132 }
1133 spin_lock_irqsave(&id->lock, flags);
1134 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1135 if (!id->views[i])
1136 break;
1137 }
1138 if (i == DEBUG_MAX_VIEWS) {
1139 pr_err("Registering view %s/%s would exceed the maximum "
1140 "number of views %i\n", id->name, view->name, i);
1141 debugfs_remove(pde);
1142 rc = -1;
1143 } else {
1144 id->views[i] = view;
1145 id->debugfs_entries[i] = pde;
1146 }
1147 spin_unlock_irqrestore(&id->lock, flags);
1148out:
1149 return rc;
1150}
1151
1152/*
1153 * debug_unregister_view:
1154 */
1155
1156int
1157debug_unregister_view(debug_info_t * id, struct debug_view *view)
1158{
1159 int rc = 0;
1160 int i;
1161 unsigned long flags;
1162
1163 if (!id)
1164 goto out;
1165 spin_lock_irqsave(&id->lock, flags);
1166 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1167 if (id->views[i] == view)
1168 break;
1169 }
1170 if (i == DEBUG_MAX_VIEWS)
1171 rc = -1;
1172 else {
1173 debugfs_remove(id->debugfs_entries[i]);
1174 id->views[i] = NULL;
1175 }
1176 spin_unlock_irqrestore(&id->lock, flags);
1177out:
1178 return rc;
1179}
1180
1181static inline char *
1182debug_get_user_string(const char __user *user_buf, size_t user_len)
1183{
1184 char* buffer;
1185
1186 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1187 if (!buffer)
1188 return ERR_PTR(-ENOMEM);
1189 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1190 kfree(buffer);
1191 return ERR_PTR(-EFAULT);
1192 }
1193 /* got the string, now strip linefeed. */
1194 if (buffer[user_len - 1] == '\n')
1195 buffer[user_len - 1] = 0;
1196 else
1197 buffer[user_len] = 0;
1198 return buffer;
1199}
1200
1201static inline int
1202debug_get_uint(char *buf)
1203{
1204 int rc;
1205
1206 buf = skip_spaces(buf);
1207 rc = simple_strtoul(buf, &buf, 10);
1208 if(*buf){
1209 rc = -EINVAL;
1210 }
1211 return rc;
1212}
1213
1214/*
1215 * functions for debug-views
1216 ***********************************
1217*/
1218
1219/*
1220 * prints out actual debug level
1221 */
1222
1223static int
1224debug_prolog_pages_fn(debug_info_t * id,
1225 struct debug_view *view, char *out_buf)
1226{
1227 return sprintf(out_buf, "%i\n", id->pages_per_area);
1228}
1229
1230/*
1231 * reads new size (number of pages per debug area)
1232 */
1233
1234static int
1235debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1236 struct file *file, const char __user *user_buf,
1237 size_t user_len, loff_t * offset)
1238{
1239 char *str;
1240 int rc,new_pages;
1241
1242 if (user_len > 0x10000)
1243 user_len = 0x10000;
1244 if (*offset != 0){
1245 rc = -EPIPE;
1246 goto out;
1247 }
1248 str = debug_get_user_string(user_buf,user_len);
1249 if(IS_ERR(str)){
1250 rc = PTR_ERR(str);
1251 goto out;
1252 }
1253 new_pages = debug_get_uint(str);
1254 if(new_pages < 0){
1255 rc = -EINVAL;
1256 goto free_str;
1257 }
1258 rc = debug_set_size(id,id->nr_areas, new_pages);
1259 if(rc != 0){
1260 rc = -EINVAL;
1261 goto free_str;
1262 }
1263 rc = user_len;
1264free_str:
1265 kfree(str);
1266out:
1267 *offset += user_len;
1268 return rc; /* number of input characters */
1269}
1270
1271/*
1272 * prints out actual debug level
1273 */
1274
1275static int
1276debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1277{
1278 int rc = 0;
1279
1280 if(id->level == DEBUG_OFF_LEVEL) {
1281 rc = sprintf(out_buf,"-\n");
1282 }
1283 else {
1284 rc = sprintf(out_buf, "%i\n", id->level);
1285 }
1286 return rc;
1287}
1288
1289/*
1290 * reads new debug level
1291 */
1292
1293static int
1294debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1295 struct file *file, const char __user *user_buf,
1296 size_t user_len, loff_t * offset)
1297{
1298 char *str;
1299 int rc,new_level;
1300
1301 if (user_len > 0x10000)
1302 user_len = 0x10000;
1303 if (*offset != 0){
1304 rc = -EPIPE;
1305 goto out;
1306 }
1307 str = debug_get_user_string(user_buf,user_len);
1308 if(IS_ERR(str)){
1309 rc = PTR_ERR(str);
1310 goto out;
1311 }
1312 if(str[0] == '-'){
1313 debug_set_level(id, DEBUG_OFF_LEVEL);
1314 rc = user_len;
1315 goto free_str;
1316 } else {
1317 new_level = debug_get_uint(str);
1318 }
1319 if(new_level < 0) {
1320 pr_warning("%s is not a valid level for a debug "
1321 "feature\n", str);
1322 rc = -EINVAL;
1323 } else {
1324 debug_set_level(id, new_level);
1325 rc = user_len;
1326 }
1327free_str:
1328 kfree(str);
1329out:
1330 *offset += user_len;
1331 return rc; /* number of input characters */
1332}
1333
1334
1335/*
1336 * flushes debug areas
1337 */
1338
1339static void debug_flush(debug_info_t* id, int area)
1340{
1341 unsigned long flags;
1342 int i,j;
1343
1344 if(!id || !id->areas)
1345 return;
1346 spin_lock_irqsave(&id->lock,flags);
1347 if(area == DEBUG_FLUSH_ALL){
1348 id->active_area = 0;
1349 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1350 for (i = 0; i < id->nr_areas; i++) {
1351 id->active_pages[i] = 0;
1352 for(j = 0; j < id->pages_per_area; j++) {
1353 memset(id->areas[i][j], 0, PAGE_SIZE);
1354 }
1355 }
1356 } else if(area >= 0 && area < id->nr_areas) {
1357 id->active_entries[area] = 0;
1358 id->active_pages[area] = 0;
1359 for(i = 0; i < id->pages_per_area; i++) {
1360 memset(id->areas[area][i],0,PAGE_SIZE);
1361 }
1362 }
1363 spin_unlock_irqrestore(&id->lock,flags);
1364}
1365
1366/*
1367 * view function: flushes debug areas
1368 */
1369
1370static int
1371debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1372 struct file *file, const char __user *user_buf,
1373 size_t user_len, loff_t * offset)
1374{
1375 char input_buf[1];
1376 int rc = user_len;
1377
1378 if (user_len > 0x10000)
1379 user_len = 0x10000;
1380 if (*offset != 0){
1381 rc = -EPIPE;
1382 goto out;
1383 }
1384 if (copy_from_user(input_buf, user_buf, 1)){
1385 rc = -EFAULT;
1386 goto out;
1387 }
1388 if(input_buf[0] == '-') {
1389 debug_flush(id, DEBUG_FLUSH_ALL);
1390 goto out;
1391 }
1392 if (isdigit(input_buf[0])) {
1393 int area = ((int) input_buf[0] - (int) '0');
1394 debug_flush(id, area);
1395 goto out;
1396 }
1397
1398 pr_info("Flushing debug data failed because %c is not a valid "
1399 "area\n", input_buf[0]);
1400
1401out:
1402 *offset += user_len;
1403 return rc; /* number of input characters */
1404}
1405
1406/*
1407 * prints debug header in raw format
1408 */
1409
1410static int
1411debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1412 int area, debug_entry_t * entry, char *out_buf)
1413{
1414 int rc;
1415
1416 rc = sizeof(debug_entry_t);
1417 memcpy(out_buf,entry,sizeof(debug_entry_t));
1418 return rc;
1419}
1420
1421/*
1422 * prints debug data in raw format
1423 */
1424
1425static int
1426debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1427 char *out_buf, const char *in_buf)
1428{
1429 int rc;
1430
1431 rc = id->buf_size;
1432 memcpy(out_buf, in_buf, id->buf_size);
1433 return rc;
1434}
1435
1436/*
1437 * prints debug data in hex/ascii format
1438 */
1439
1440static int
1441debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1442 char *out_buf, const char *in_buf)
1443{
1444 int i, rc = 0;
1445
1446 for (i = 0; i < id->buf_size; i++) {
1447 rc += sprintf(out_buf + rc, "%02x ",
1448 ((unsigned char *) in_buf)[i]);
1449 }
1450 rc += sprintf(out_buf + rc, "| ");
1451 for (i = 0; i < id->buf_size; i++) {
1452 unsigned char c = in_buf[i];
1453 if (isascii(c) && isprint(c))
1454 rc += sprintf(out_buf + rc, "%c", c);
1455 else
1456 rc += sprintf(out_buf + rc, ".");
1457 }
1458 rc += sprintf(out_buf + rc, "\n");
1459 return rc;
1460}
1461
1462/*
1463 * prints header for debug entry
1464 */
1465
1466int
1467debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1468 int area, debug_entry_t * entry, char *out_buf)
1469{
1470 struct timespec time_spec;
1471 char *except_str;
1472 unsigned long caller;
1473 int rc = 0;
1474 unsigned int level;
1475
1476 level = entry->id.fields.level;
1477 stck_to_timespec(entry->id.stck, &time_spec);
1478
1479 if (entry->id.fields.exception)
1480 except_str = "*";
1481 else
1482 except_str = "-";
1483 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1484 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1485 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1486 except_str, entry->id.fields.cpuid, (void *) caller);
1487 return rc;
1488}
1489
1490/*
1491 * prints debug data sprintf-formated:
1492 * debug_sprinf_event/exception calls must be used together with this view
1493 */
1494
1495#define DEBUG_SPRINTF_MAX_ARGS 10
1496
1497static int
1498debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1499 char *out_buf, debug_sprintf_entry_t *curr_event)
1500{
1501 int num_longs, num_used_args = 0,i, rc = 0;
1502 int index[DEBUG_SPRINTF_MAX_ARGS];
1503
1504 /* count of longs fit into one entry */
1505 num_longs = id->buf_size / sizeof(long);
1506
1507 if(num_longs < 1)
1508 goto out; /* bufsize of entry too small */
1509 if(num_longs == 1) {
1510 /* no args, we use only the string */
1511 strcpy(out_buf, curr_event->string);
1512 rc = strlen(curr_event->string);
1513 goto out;
1514 }
1515
1516 /* number of arguments used for sprintf (without the format string) */
1517 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1518
1519 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1520
1521 for(i = 0; i < num_used_args; i++)
1522 index[i] = i;
1523
1524 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1525 curr_event->args[index[1]], curr_event->args[index[2]],
1526 curr_event->args[index[3]], curr_event->args[index[4]],
1527 curr_event->args[index[5]], curr_event->args[index[6]],
1528 curr_event->args[index[7]], curr_event->args[index[8]],
1529 curr_event->args[index[9]]);
1530
1531out:
1532
1533 return rc;
1534}
1535
1536/*
1537 * clean up module
1538 */
1539static void __exit debug_exit(void)
1540{
1541 debugfs_remove(debug_debugfs_root_entry);
1542 unregister_sysctl_table(s390dbf_sysctl_header);
1543 return;
1544}
1545
1546/*
1547 * module definitions
1548 */
1549postcore_initcall(debug_init);
1550module_exit(debug_exit);
1551MODULE_LICENSE("GPL");
1552
1553EXPORT_SYMBOL(debug_register);
1554EXPORT_SYMBOL(debug_unregister);
1555EXPORT_SYMBOL(debug_set_level);
1556EXPORT_SYMBOL(debug_stop_all);
1557EXPORT_SYMBOL(debug_register_view);
1558EXPORT_SYMBOL(debug_unregister_view);
1559EXPORT_SYMBOL(debug_event_common);
1560EXPORT_SYMBOL(debug_exception_common);
1561EXPORT_SYMBOL(debug_hex_ascii_view);
1562EXPORT_SYMBOL(debug_raw_view);
1563EXPORT_SYMBOL(debug_dflt_header_fn);
1564EXPORT_SYMBOL(debug_sprintf_view);
1565EXPORT_SYMBOL(debug_sprintf_exception);
1566EXPORT_SYMBOL(debug_sprintf_event);