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1// SPDX-License-Identifier: GPL-2.0
2/*
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 <linux/uaccess.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/debugfs.h>
28
29#include <asm/debug.h>
30
31#define DEBUG_PROLOG_ENTRY -1
32
33#define ALL_AREAS 0 /* copy all debug areas */
34#define NO_AREAS 1 /* copy no debug areas */
35
36/* typedefs */
37
38typedef struct file_private_info {
39 loff_t offset; /* offset of last read in file */
40 int act_area; /* number of last formated area */
41 int act_page; /* act page in given area */
42 int act_entry; /* last formated entry (offset */
43 /* relative to beginning of last */
44 /* formated page) */
45 size_t act_entry_offset; /* up to this offset we copied */
46 /* in last read the last formated */
47 /* entry to userland */
48 char temp_buf[2048]; /* buffer for output */
49 debug_info_t *debug_info_org; /* original debug information */
50 debug_info_t *debug_info_snap; /* snapshot of debug information */
51 struct debug_view *view; /* used view of debug info */
52} file_private_info_t;
53
54typedef struct {
55 char *string;
56 /*
57 * This assumes that all args are converted into longs
58 * on L/390 this is the case for all types of parameter
59 * except of floats, and long long (32 bit)
60 *
61 */
62 long args[0];
63} debug_sprintf_entry_t;
64
65/* internal function prototyes */
66
67static int debug_init(void);
68static ssize_t debug_output(struct file *file, char __user *user_buf,
69 size_t user_len, loff_t *offset);
70static ssize_t debug_input(struct file *file, const char __user *user_buf,
71 size_t user_len, loff_t *offset);
72static int debug_open(struct inode *inode, struct file *file);
73static int debug_close(struct inode *inode, struct file *file);
74static debug_info_t *debug_info_create(const char *name, int pages_per_area,
75 int nr_areas, int buf_size, umode_t mode);
76static void debug_info_get(debug_info_t *);
77static void debug_info_put(debug_info_t *);
78static int debug_prolog_level_fn(debug_info_t *id,
79 struct debug_view *view, char *out_buf);
80static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
81 struct file *file, const char __user *user_buf,
82 size_t user_buf_size, loff_t *offset);
83static int debug_prolog_pages_fn(debug_info_t *id,
84 struct debug_view *view, char *out_buf);
85static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
86 struct file *file, const char __user *user_buf,
87 size_t user_buf_size, loff_t *offset);
88static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
89 struct file *file, const char __user *user_buf,
90 size_t user_buf_size, loff_t *offset);
91static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
92 char *out_buf, const char *in_buf);
93static int debug_raw_format_fn(debug_info_t *id,
94 struct debug_view *view, char *out_buf,
95 const char *in_buf);
96static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
97 int area, debug_entry_t *entry, char *out_buf);
98
99static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
100 char *out_buf, debug_sprintf_entry_t *curr_event);
101
102/* globals */
103
104struct debug_view debug_raw_view = {
105 "raw",
106 NULL,
107 &debug_raw_header_fn,
108 &debug_raw_format_fn,
109 NULL,
110 NULL
111};
112EXPORT_SYMBOL(debug_raw_view);
113
114struct debug_view debug_hex_ascii_view = {
115 "hex_ascii",
116 NULL,
117 &debug_dflt_header_fn,
118 &debug_hex_ascii_format_fn,
119 NULL,
120 NULL
121};
122EXPORT_SYMBOL(debug_hex_ascii_view);
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};
159EXPORT_SYMBOL(debug_sprintf_view);
160
161/* used by dump analysis tools to determine version of debug feature */
162static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
163
164/* static globals */
165
166static debug_info_t *debug_area_first;
167static debug_info_t *debug_area_last;
168static DEFINE_MUTEX(debug_mutex);
169
170static int initialized;
171static int debug_critical;
172
173static const struct file_operations debug_file_ops = {
174 .owner = THIS_MODULE,
175 .read = debug_output,
176 .write = debug_input,
177 .open = debug_open,
178 .release = debug_close,
179 .llseek = no_llseek,
180};
181
182static struct dentry *debug_debugfs_root_entry;
183
184/* functions */
185
186/*
187 * debug_areas_alloc
188 * - Debug areas are implemented as a threedimensonal array:
189 * areas[areanumber][pagenumber][pageoffset]
190 */
191
192static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
193{
194 debug_entry_t ***areas;
195 int i, j;
196
197 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL);
198 if (!areas)
199 goto fail_malloc_areas;
200 for (i = 0; i < nr_areas; i++) {
201 areas[i] = kmalloc_array(pages_per_area,
202 sizeof(debug_entry_t *),
203 GFP_KERNEL);
204 if (!areas[i])
205 goto fail_malloc_areas2;
206 for (j = 0; j < pages_per_area; j++) {
207 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
208 if (!areas[i][j]) {
209 for (j--; j >= 0 ; j--)
210 kfree(areas[i][j]);
211 kfree(areas[i]);
212 goto fail_malloc_areas2;
213 }
214 }
215 }
216 return areas;
217
218fail_malloc_areas2:
219 for (i--; i >= 0; i--) {
220 for (j = 0; j < pages_per_area; j++)
221 kfree(areas[i][j]);
222 kfree(areas[i]);
223 }
224 kfree(areas);
225fail_malloc_areas:
226 return NULL;
227}
228
229/*
230 * debug_info_alloc
231 * - alloc new debug-info
232 */
233static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
234 int nr_areas, int buf_size, int level,
235 int mode)
236{
237 debug_info_t *rc;
238
239 /* alloc everything */
240 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
241 if (!rc)
242 goto fail_malloc_rc;
243 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
244 if (!rc->active_entries)
245 goto fail_malloc_active_entries;
246 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
247 if (!rc->active_pages)
248 goto fail_malloc_active_pages;
249 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
250 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
251 if (!rc->areas)
252 goto fail_malloc_areas;
253 } else {
254 rc->areas = NULL;
255 }
256
257 /* initialize members */
258 spin_lock_init(&rc->lock);
259 rc->pages_per_area = pages_per_area;
260 rc->nr_areas = nr_areas;
261 rc->active_area = 0;
262 rc->level = level;
263 rc->buf_size = buf_size;
264 rc->entry_size = sizeof(debug_entry_t) + buf_size;
265 strlcpy(rc->name, name, sizeof(rc->name));
266 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
267 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
268 refcount_set(&(rc->ref_count), 0);
269
270 return rc;
271
272fail_malloc_areas:
273 kfree(rc->active_pages);
274fail_malloc_active_pages:
275 kfree(rc->active_entries);
276fail_malloc_active_entries:
277 kfree(rc);
278fail_malloc_rc:
279 return NULL;
280}
281
282/*
283 * debug_areas_free
284 * - free all debug areas
285 */
286static void debug_areas_free(debug_info_t *db_info)
287{
288 int i, j;
289
290 if (!db_info->areas)
291 return;
292 for (i = 0; i < db_info->nr_areas; i++) {
293 for (j = 0; j < db_info->pages_per_area; j++)
294 kfree(db_info->areas[i][j]);
295 kfree(db_info->areas[i]);
296 }
297 kfree(db_info->areas);
298 db_info->areas = NULL;
299}
300
301/*
302 * debug_info_free
303 * - free memory debug-info
304 */
305static void debug_info_free(debug_info_t *db_info)
306{
307 debug_areas_free(db_info);
308 kfree(db_info->active_entries);
309 kfree(db_info->active_pages);
310 kfree(db_info);
311}
312
313/*
314 * debug_info_create
315 * - create new debug-info
316 */
317
318static debug_info_t *debug_info_create(const char *name, int pages_per_area,
319 int nr_areas, int buf_size, umode_t mode)
320{
321 debug_info_t *rc;
322
323 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
324 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
325 if (!rc)
326 goto out;
327
328 rc->mode = mode & ~S_IFMT;
329
330 /* create root directory */
331 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
332 debug_debugfs_root_entry);
333
334 /* append new element to linked list */
335 if (!debug_area_first) {
336 /* first element in list */
337 debug_area_first = rc;
338 rc->prev = NULL;
339 } else {
340 /* append element to end of list */
341 debug_area_last->next = rc;
342 rc->prev = debug_area_last;
343 }
344 debug_area_last = rc;
345 rc->next = NULL;
346
347 refcount_set(&rc->ref_count, 1);
348out:
349 return rc;
350}
351
352/*
353 * debug_info_copy
354 * - copy debug-info
355 */
356static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
357{
358 unsigned long flags;
359 debug_info_t *rc;
360 int i, j;
361
362 /* get a consistent copy of the debug areas */
363 do {
364 rc = debug_info_alloc(in->name, in->pages_per_area,
365 in->nr_areas, in->buf_size, in->level, mode);
366 spin_lock_irqsave(&in->lock, flags);
367 if (!rc)
368 goto out;
369 /* has something changed in the meantime ? */
370 if ((rc->pages_per_area == in->pages_per_area) &&
371 (rc->nr_areas == in->nr_areas)) {
372 break;
373 }
374 spin_unlock_irqrestore(&in->lock, flags);
375 debug_info_free(rc);
376 } while (1);
377
378 if (mode == NO_AREAS)
379 goto out;
380
381 for (i = 0; i < in->nr_areas; i++) {
382 for (j = 0; j < in->pages_per_area; j++)
383 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
384 }
385out:
386 spin_unlock_irqrestore(&in->lock, flags);
387 return rc;
388}
389
390/*
391 * debug_info_get
392 * - increments reference count for debug-info
393 */
394static void debug_info_get(debug_info_t *db_info)
395{
396 if (db_info)
397 refcount_inc(&db_info->ref_count);
398}
399
400/*
401 * debug_info_put:
402 * - decreases reference count for debug-info and frees it if necessary
403 */
404static void debug_info_put(debug_info_t *db_info)
405{
406 int i;
407
408 if (!db_info)
409 return;
410 if (refcount_dec_and_test(&db_info->ref_count)) {
411 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
412 if (!db_info->views[i])
413 continue;
414 debugfs_remove(db_info->debugfs_entries[i]);
415 }
416 debugfs_remove(db_info->debugfs_root_entry);
417 if (db_info == debug_area_first)
418 debug_area_first = db_info->next;
419 if (db_info == debug_area_last)
420 debug_area_last = db_info->prev;
421 if (db_info->prev)
422 db_info->prev->next = db_info->next;
423 if (db_info->next)
424 db_info->next->prev = db_info->prev;
425 debug_info_free(db_info);
426 }
427}
428
429/*
430 * debug_format_entry:
431 * - format one debug entry and return size of formated data
432 */
433static int debug_format_entry(file_private_info_t *p_info)
434{
435 debug_info_t *id_snap = p_info->debug_info_snap;
436 struct debug_view *view = p_info->view;
437 debug_entry_t *act_entry;
438 size_t len = 0;
439
440 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
441 /* print prolog */
442 if (view->prolog_proc)
443 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
444 goto out;
445 }
446 if (!id_snap->areas) /* this is true, if we have a prolog only view */
447 goto out; /* or if 'pages_per_area' is 0 */
448 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
449 [p_info->act_page] + p_info->act_entry);
450
451 if (act_entry->id.stck == 0LL)
452 goto out; /* empty entry */
453 if (view->header_proc)
454 len += view->header_proc(id_snap, view, p_info->act_area,
455 act_entry, p_info->temp_buf + len);
456 if (view->format_proc)
457 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
458 DEBUG_DATA(act_entry));
459out:
460 return len;
461}
462
463/*
464 * debug_next_entry:
465 * - goto next entry in p_info
466 */
467static inline int debug_next_entry(file_private_info_t *p_info)
468{
469 debug_info_t *id;
470
471 id = p_info->debug_info_snap;
472 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
473 p_info->act_entry = 0;
474 p_info->act_page = 0;
475 goto out;
476 }
477 if (!id->areas)
478 return 1;
479 p_info->act_entry += id->entry_size;
480 /* switch to next page, if we reached the end of the page */
481 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
482 /* next page */
483 p_info->act_entry = 0;
484 p_info->act_page += 1;
485 if ((p_info->act_page % id->pages_per_area) == 0) {
486 /* next area */
487 p_info->act_area++;
488 p_info->act_page = 0;
489 }
490 if (p_info->act_area >= id->nr_areas)
491 return 1;
492 }
493out:
494 return 0;
495}
496
497/*
498 * debug_output:
499 * - called for user read()
500 * - copies formated debug entries to the user buffer
501 */
502static ssize_t debug_output(struct file *file, /* file descriptor */
503 char __user *user_buf, /* user buffer */
504 size_t len, /* length of buffer */
505 loff_t *offset) /* offset in the file */
506{
507 size_t count = 0;
508 size_t entry_offset;
509 file_private_info_t *p_info;
510
511 p_info = (file_private_info_t *) file->private_data;
512 if (*offset != p_info->offset)
513 return -EPIPE;
514 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
515 return 0;
516 entry_offset = p_info->act_entry_offset;
517 while (count < len) {
518 int formatted_line_residue;
519 int formatted_line_size;
520 int user_buf_residue;
521 size_t copy_size;
522
523 formatted_line_size = debug_format_entry(p_info);
524 formatted_line_residue = formatted_line_size - entry_offset;
525 user_buf_residue = len-count;
526 copy_size = min(user_buf_residue, formatted_line_residue);
527 if (copy_size) {
528 if (copy_to_user(user_buf + count, p_info->temp_buf
529 + entry_offset, copy_size))
530 return -EFAULT;
531 count += copy_size;
532 entry_offset += copy_size;
533 }
534 if (copy_size == formatted_line_residue) {
535 entry_offset = 0;
536 if (debug_next_entry(p_info))
537 goto out;
538 }
539 }
540out:
541 p_info->offset = *offset + count;
542 p_info->act_entry_offset = entry_offset;
543 *offset = p_info->offset;
544 return count;
545}
546
547/*
548 * debug_input:
549 * - called for user write()
550 * - calls input function of view
551 */
552static ssize_t debug_input(struct file *file, const char __user *user_buf,
553 size_t length, loff_t *offset)
554{
555 file_private_info_t *p_info;
556 int rc = 0;
557
558 mutex_lock(&debug_mutex);
559 p_info = ((file_private_info_t *) file->private_data);
560 if (p_info->view->input_proc) {
561 rc = p_info->view->input_proc(p_info->debug_info_org,
562 p_info->view, file, user_buf,
563 length, offset);
564 } else {
565 rc = -EPERM;
566 }
567 mutex_unlock(&debug_mutex);
568 return rc; /* number of input characters */
569}
570
571/*
572 * debug_open:
573 * - called for user open()
574 * - copies formated output to private_data area of the file
575 * handle
576 */
577static int debug_open(struct inode *inode, struct file *file)
578{
579 debug_info_t *debug_info, *debug_info_snapshot;
580 file_private_info_t *p_info;
581 int i, rc = 0;
582
583 mutex_lock(&debug_mutex);
584 debug_info = file_inode(file)->i_private;
585 /* find debug view */
586 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
587 if (!debug_info->views[i])
588 continue;
589 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
590 goto found; /* found view ! */
591 }
592 /* no entry found */
593 rc = -EINVAL;
594 goto out;
595
596found:
597
598 /* Make snapshot of current debug areas to get it consistent. */
599 /* To copy all the areas is only needed, if we have a view which */
600 /* formats the debug areas. */
601
602 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
603 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
604 else
605 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
606
607 if (!debug_info_snapshot) {
608 rc = -ENOMEM;
609 goto out;
610 }
611 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
612 if (!p_info) {
613 debug_info_free(debug_info_snapshot);
614 rc = -ENOMEM;
615 goto out;
616 }
617 p_info->offset = 0;
618 p_info->debug_info_snap = debug_info_snapshot;
619 p_info->debug_info_org = debug_info;
620 p_info->view = debug_info->views[i];
621 p_info->act_area = 0;
622 p_info->act_page = 0;
623 p_info->act_entry = DEBUG_PROLOG_ENTRY;
624 p_info->act_entry_offset = 0;
625 file->private_data = p_info;
626 debug_info_get(debug_info);
627 nonseekable_open(inode, file);
628out:
629 mutex_unlock(&debug_mutex);
630 return rc;
631}
632
633/*
634 * debug_close:
635 * - called for user close()
636 * - deletes private_data area of the file handle
637 */
638static int debug_close(struct inode *inode, struct file *file)
639{
640 file_private_info_t *p_info;
641
642 p_info = (file_private_info_t *) file->private_data;
643 if (p_info->debug_info_snap)
644 debug_info_free(p_info->debug_info_snap);
645 debug_info_put(p_info->debug_info_org);
646 kfree(file->private_data);
647 return 0; /* success */
648}
649
650/**
651 * debug_register_mode() - creates and initializes debug area.
652 *
653 * @name: Name of debug log (e.g. used for debugfs entry)
654 * @pages_per_area: Number of pages, which will be allocated per area
655 * @nr_areas: Number of debug areas
656 * @buf_size: Size of data area in each debug entry
657 * @mode: File mode for debugfs files. E.g. S_IRWXUGO
658 * @uid: User ID for debugfs files. Currently only 0 is supported.
659 * @gid: Group ID for debugfs files. Currently only 0 is supported.
660 *
661 * Return:
662 * - Handle for generated debug area
663 * - %NULL if register failed
664 *
665 * Allocates memory for a debug log.
666 * Must not be called within an interrupt handler.
667 */
668debug_info_t *debug_register_mode(const char *name, int pages_per_area,
669 int nr_areas, int buf_size, umode_t mode,
670 uid_t uid, gid_t gid)
671{
672 debug_info_t *rc = NULL;
673
674 /* Since debugfs currently does not support uid/gid other than root, */
675 /* we do not allow gid/uid != 0 until we get support for that. */
676 if ((uid != 0) || (gid != 0))
677 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
678 BUG_ON(!initialized);
679 mutex_lock(&debug_mutex);
680
681 /* create new debug_info */
682 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
683 if (!rc)
684 goto out;
685 debug_register_view(rc, &debug_level_view);
686 debug_register_view(rc, &debug_flush_view);
687 debug_register_view(rc, &debug_pages_view);
688out:
689 if (!rc)
690 pr_err("Registering debug feature %s failed\n", name);
691 mutex_unlock(&debug_mutex);
692 return rc;
693}
694EXPORT_SYMBOL(debug_register_mode);
695
696/**
697 * debug_register() - creates and initializes debug area with default file mode.
698 *
699 * @name: Name of debug log (e.g. used for debugfs entry)
700 * @pages_per_area: Number of pages, which will be allocated per area
701 * @nr_areas: Number of debug areas
702 * @buf_size: Size of data area in each debug entry
703 *
704 * Return:
705 * - Handle for generated debug area
706 * - %NULL if register failed
707 *
708 * Allocates memory for a debug log.
709 * The debugfs file mode access permissions are read and write for user.
710 * Must not be called within an interrupt handler.
711 */
712debug_info_t *debug_register(const char *name, int pages_per_area,
713 int nr_areas, int buf_size)
714{
715 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
716 S_IRUSR | S_IWUSR, 0, 0);
717}
718EXPORT_SYMBOL(debug_register);
719
720/**
721 * debug_unregister() - give back debug area.
722 *
723 * @id: handle for debug log
724 *
725 * Return:
726 * none
727 */
728void debug_unregister(debug_info_t *id)
729{
730 if (!id)
731 return;
732 mutex_lock(&debug_mutex);
733 debug_info_put(id);
734 mutex_unlock(&debug_mutex);
735}
736EXPORT_SYMBOL(debug_unregister);
737
738/*
739 * debug_set_size:
740 * - set area size (number of pages) and number of areas
741 */
742static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
743{
744 debug_entry_t ***new_areas;
745 unsigned long flags;
746 int rc = 0;
747
748 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
749 return -EINVAL;
750 if (pages_per_area > 0) {
751 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
752 if (!new_areas) {
753 pr_info("Allocating memory for %i pages failed\n",
754 pages_per_area);
755 rc = -ENOMEM;
756 goto out;
757 }
758 } else {
759 new_areas = NULL;
760 }
761 spin_lock_irqsave(&id->lock, flags);
762 debug_areas_free(id);
763 id->areas = new_areas;
764 id->nr_areas = nr_areas;
765 id->pages_per_area = pages_per_area;
766 id->active_area = 0;
767 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
768 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
769 spin_unlock_irqrestore(&id->lock, flags);
770 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
771out:
772 return rc;
773}
774
775/**
776 * debug_set_level() - Sets new actual debug level if new_level is valid.
777 *
778 * @id: handle for debug log
779 * @new_level: new debug level
780 *
781 * Return:
782 * none
783 */
784void debug_set_level(debug_info_t *id, int new_level)
785{
786 unsigned long flags;
787
788 if (!id)
789 return;
790 spin_lock_irqsave(&id->lock, flags);
791 if (new_level == DEBUG_OFF_LEVEL) {
792 id->level = DEBUG_OFF_LEVEL;
793 pr_info("%s: switched off\n", id->name);
794 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
795 pr_info("%s: level %i is out of range (%i - %i)\n",
796 id->name, new_level, 0, DEBUG_MAX_LEVEL);
797 } else {
798 id->level = new_level;
799 }
800 spin_unlock_irqrestore(&id->lock, flags);
801}
802EXPORT_SYMBOL(debug_set_level);
803
804/*
805 * proceed_active_entry:
806 * - set active entry to next in the ring buffer
807 */
808static inline void proceed_active_entry(debug_info_t *id)
809{
810 if ((id->active_entries[id->active_area] += id->entry_size)
811 > (PAGE_SIZE - id->entry_size)) {
812 id->active_entries[id->active_area] = 0;
813 id->active_pages[id->active_area] =
814 (id->active_pages[id->active_area] + 1) %
815 id->pages_per_area;
816 }
817}
818
819/*
820 * proceed_active_area:
821 * - set active area to next in the ring buffer
822 */
823static inline void proceed_active_area(debug_info_t *id)
824{
825 id->active_area++;
826 id->active_area = id->active_area % id->nr_areas;
827}
828
829/*
830 * get_active_entry:
831 */
832static inline debug_entry_t *get_active_entry(debug_info_t *id)
833{
834 return (debug_entry_t *) (((char *) id->areas[id->active_area]
835 [id->active_pages[id->active_area]]) +
836 id->active_entries[id->active_area]);
837}
838
839/*
840 * debug_finish_entry:
841 * - set timestamp, caller address, cpu number etc.
842 */
843
844static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
845 int level, int exception)
846{
847 active->id.stck = get_tod_clock_fast() -
848 *(unsigned long long *) &tod_clock_base[1];
849 active->id.fields.cpuid = smp_processor_id();
850 active->caller = __builtin_return_address(0);
851 active->id.fields.exception = exception;
852 active->id.fields.level = level;
853 proceed_active_entry(id);
854 if (exception)
855 proceed_active_area(id);
856}
857
858static int debug_stoppable = 1;
859static int debug_active = 1;
860
861#define CTL_S390DBF_STOPPABLE 5678
862#define CTL_S390DBF_ACTIVE 5679
863
864/*
865 * proc handler for the running debug_active sysctl
866 * always allow read, allow write only if debug_stoppable is set or
867 * if debug_active is already off
868 */
869static int s390dbf_procactive(struct ctl_table *table, int write,
870 void __user *buffer, size_t *lenp, loff_t *ppos)
871{
872 if (!write || debug_stoppable || !debug_active)
873 return proc_dointvec(table, write, buffer, lenp, ppos);
874 else
875 return 0;
876}
877
878static struct ctl_table s390dbf_table[] = {
879 {
880 .procname = "debug_stoppable",
881 .data = &debug_stoppable,
882 .maxlen = sizeof(int),
883 .mode = S_IRUGO | S_IWUSR,
884 .proc_handler = proc_dointvec,
885 },
886 {
887 .procname = "debug_active",
888 .data = &debug_active,
889 .maxlen = sizeof(int),
890 .mode = S_IRUGO | S_IWUSR,
891 .proc_handler = s390dbf_procactive,
892 },
893 { }
894};
895
896static struct ctl_table s390dbf_dir_table[] = {
897 {
898 .procname = "s390dbf",
899 .maxlen = 0,
900 .mode = S_IRUGO | S_IXUGO,
901 .child = s390dbf_table,
902 },
903 { }
904};
905
906static struct ctl_table_header *s390dbf_sysctl_header;
907
908/**
909 * debug_stop_all() - stops the debug feature if stopping is allowed.
910 *
911 * Return:
912 * - none
913 *
914 * Currently used in case of a kernel oops.
915 */
916void debug_stop_all(void)
917{
918 if (debug_stoppable)
919 debug_active = 0;
920}
921EXPORT_SYMBOL(debug_stop_all);
922
923/**
924 * debug_set_critical() - event/exception functions try lock instead of spin.
925 *
926 * Return:
927 * - none
928 *
929 * Currently used in case of stopping all CPUs but the current one.
930 * Once in this state, functions to write a debug entry for an
931 * event or exception no longer spin on the debug area lock,
932 * but only try to get it and fail if they do not get the lock.
933 */
934void debug_set_critical(void)
935{
936 debug_critical = 1;
937}
938
939/*
940 * debug_event_common:
941 * - write debug entry with given size
942 */
943debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
944 int len)
945{
946 debug_entry_t *active;
947 unsigned long flags;
948
949 if (!debug_active || !id->areas)
950 return NULL;
951 if (debug_critical) {
952 if (!spin_trylock_irqsave(&id->lock, flags))
953 return NULL;
954 } else {
955 spin_lock_irqsave(&id->lock, flags);
956 }
957 do {
958 active = get_active_entry(id);
959 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
960 if (len < id->buf_size)
961 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
962 debug_finish_entry(id, active, level, 0);
963 len -= id->buf_size;
964 buf += id->buf_size;
965 } while (len > 0);
966
967 spin_unlock_irqrestore(&id->lock, flags);
968 return active;
969}
970EXPORT_SYMBOL(debug_event_common);
971
972/*
973 * debug_exception_common:
974 * - write debug entry with given size and switch to next debug area
975 */
976debug_entry_t *debug_exception_common(debug_info_t *id, int level,
977 const void *buf, int len)
978{
979 debug_entry_t *active;
980 unsigned long flags;
981
982 if (!debug_active || !id->areas)
983 return NULL;
984 if (debug_critical) {
985 if (!spin_trylock_irqsave(&id->lock, flags))
986 return NULL;
987 } else {
988 spin_lock_irqsave(&id->lock, flags);
989 }
990 do {
991 active = get_active_entry(id);
992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
993 if (len < id->buf_size)
994 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
995 debug_finish_entry(id, active, level, len <= id->buf_size);
996 len -= id->buf_size;
997 buf += id->buf_size;
998 } while (len > 0);
999
1000 spin_unlock_irqrestore(&id->lock, flags);
1001 return active;
1002}
1003EXPORT_SYMBOL(debug_exception_common);
1004
1005/*
1006 * counts arguments in format string for sprintf view
1007 */
1008static inline int debug_count_numargs(char *string)
1009{
1010 int numargs = 0;
1011
1012 while (*string) {
1013 if (*string++ == '%')
1014 numargs++;
1015 }
1016 return numargs;
1017}
1018
1019/*
1020 * debug_sprintf_event:
1021 */
1022debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1023{
1024 debug_sprintf_entry_t *curr_event;
1025 debug_entry_t *active;
1026 unsigned long flags;
1027 int numargs, idx;
1028 va_list ap;
1029
1030 if (!debug_active || !id->areas)
1031 return NULL;
1032 numargs = debug_count_numargs(string);
1033
1034 if (debug_critical) {
1035 if (!spin_trylock_irqsave(&id->lock, flags))
1036 return NULL;
1037 } else {
1038 spin_lock_irqsave(&id->lock, flags);
1039 }
1040 active = get_active_entry(id);
1041 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1042 va_start(ap, string);
1043 curr_event->string = string;
1044 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1045 curr_event->args[idx] = va_arg(ap, long);
1046 va_end(ap);
1047 debug_finish_entry(id, active, level, 0);
1048 spin_unlock_irqrestore(&id->lock, flags);
1049
1050 return active;
1051}
1052EXPORT_SYMBOL(__debug_sprintf_event);
1053
1054/*
1055 * debug_sprintf_exception:
1056 */
1057debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1058{
1059 debug_sprintf_entry_t *curr_event;
1060 debug_entry_t *active;
1061 unsigned long flags;
1062 int numargs, idx;
1063 va_list ap;
1064
1065 if (!debug_active || !id->areas)
1066 return NULL;
1067
1068 numargs = debug_count_numargs(string);
1069
1070 if (debug_critical) {
1071 if (!spin_trylock_irqsave(&id->lock, flags))
1072 return NULL;
1073 } else {
1074 spin_lock_irqsave(&id->lock, flags);
1075 }
1076 active = get_active_entry(id);
1077 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1078 va_start(ap, string);
1079 curr_event->string = string;
1080 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1081 curr_event->args[idx] = va_arg(ap, long);
1082 va_end(ap);
1083 debug_finish_entry(id, active, level, 1);
1084 spin_unlock_irqrestore(&id->lock, flags);
1085
1086 return active;
1087}
1088EXPORT_SYMBOL(__debug_sprintf_exception);
1089
1090/**
1091 * debug_register_view() - registers new debug view and creates debugfs
1092 * dir entry
1093 *
1094 * @id: handle for debug log
1095 * @view: pointer to debug view struct
1096 *
1097 * Return:
1098 * - 0 : ok
1099 * - < 0: Error
1100 */
1101int debug_register_view(debug_info_t *id, struct debug_view *view)
1102{
1103 unsigned long flags;
1104 struct dentry *pde;
1105 umode_t mode;
1106 int rc = 0;
1107 int i;
1108
1109 if (!id)
1110 goto out;
1111 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1112 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1113 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1114 if (!view->input_proc)
1115 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1116 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1117 id, &debug_file_ops);
1118 spin_lock_irqsave(&id->lock, flags);
1119 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1120 if (!id->views[i])
1121 break;
1122 }
1123 if (i == DEBUG_MAX_VIEWS) {
1124 pr_err("Registering view %s/%s would exceed the maximum "
1125 "number of views %i\n", id->name, view->name, i);
1126 rc = -1;
1127 } else {
1128 id->views[i] = view;
1129 id->debugfs_entries[i] = pde;
1130 }
1131 spin_unlock_irqrestore(&id->lock, flags);
1132 if (rc)
1133 debugfs_remove(pde);
1134out:
1135 return rc;
1136}
1137EXPORT_SYMBOL(debug_register_view);
1138
1139/**
1140 * debug_unregister_view() - unregisters debug view and removes debugfs
1141 * dir entry
1142 *
1143 * @id: handle for debug log
1144 * @view: pointer to debug view struct
1145 *
1146 * Return:
1147 * - 0 : ok
1148 * - < 0: Error
1149 */
1150int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1151{
1152 struct dentry *dentry = NULL;
1153 unsigned long flags;
1154 int i, rc = 0;
1155
1156 if (!id)
1157 goto out;
1158 spin_lock_irqsave(&id->lock, flags);
1159 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1160 if (id->views[i] == view)
1161 break;
1162 }
1163 if (i == DEBUG_MAX_VIEWS) {
1164 rc = -1;
1165 } else {
1166 dentry = id->debugfs_entries[i];
1167 id->views[i] = NULL;
1168 id->debugfs_entries[i] = NULL;
1169 }
1170 spin_unlock_irqrestore(&id->lock, flags);
1171 debugfs_remove(dentry);
1172out:
1173 return rc;
1174}
1175EXPORT_SYMBOL(debug_unregister_view);
1176
1177static inline char *debug_get_user_string(const char __user *user_buf,
1178 size_t user_len)
1179{
1180 char *buffer;
1181
1182 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1183 if (!buffer)
1184 return ERR_PTR(-ENOMEM);
1185 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1186 kfree(buffer);
1187 return ERR_PTR(-EFAULT);
1188 }
1189 /* got the string, now strip linefeed. */
1190 if (buffer[user_len - 1] == '\n')
1191 buffer[user_len - 1] = 0;
1192 else
1193 buffer[user_len] = 0;
1194 return buffer;
1195}
1196
1197static inline int debug_get_uint(char *buf)
1198{
1199 int rc;
1200
1201 buf = skip_spaces(buf);
1202 rc = simple_strtoul(buf, &buf, 10);
1203 if (*buf)
1204 rc = -EINVAL;
1205 return rc;
1206}
1207
1208/*
1209 * functions for debug-views
1210 ***********************************
1211*/
1212
1213/*
1214 * prints out actual debug level
1215 */
1216
1217static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1218 char *out_buf)
1219{
1220 return sprintf(out_buf, "%i\n", id->pages_per_area);
1221}
1222
1223/*
1224 * reads new size (number of pages per debug area)
1225 */
1226
1227static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1228 struct file *file, const char __user *user_buf,
1229 size_t user_len, loff_t *offset)
1230{
1231 int rc, new_pages;
1232 char *str;
1233
1234 if (user_len > 0x10000)
1235 user_len = 0x10000;
1236 if (*offset != 0) {
1237 rc = -EPIPE;
1238 goto out;
1239 }
1240 str = debug_get_user_string(user_buf, user_len);
1241 if (IS_ERR(str)) {
1242 rc = PTR_ERR(str);
1243 goto out;
1244 }
1245 new_pages = debug_get_uint(str);
1246 if (new_pages < 0) {
1247 rc = -EINVAL;
1248 goto free_str;
1249 }
1250 rc = debug_set_size(id, id->nr_areas, new_pages);
1251 if (rc != 0) {
1252 rc = -EINVAL;
1253 goto free_str;
1254 }
1255 rc = user_len;
1256free_str:
1257 kfree(str);
1258out:
1259 *offset += user_len;
1260 return rc; /* number of input characters */
1261}
1262
1263/*
1264 * prints out actual debug level
1265 */
1266static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1267 char *out_buf)
1268{
1269 int rc = 0;
1270
1271 if (id->level == DEBUG_OFF_LEVEL)
1272 rc = sprintf(out_buf, "-\n");
1273 else
1274 rc = sprintf(out_buf, "%i\n", id->level);
1275 return rc;
1276}
1277
1278/*
1279 * reads new debug level
1280 */
1281static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1282 struct file *file, const char __user *user_buf,
1283 size_t user_len, loff_t *offset)
1284{
1285 int rc, new_level;
1286 char *str;
1287
1288 if (user_len > 0x10000)
1289 user_len = 0x10000;
1290 if (*offset != 0) {
1291 rc = -EPIPE;
1292 goto out;
1293 }
1294 str = debug_get_user_string(user_buf, user_len);
1295 if (IS_ERR(str)) {
1296 rc = PTR_ERR(str);
1297 goto out;
1298 }
1299 if (str[0] == '-') {
1300 debug_set_level(id, DEBUG_OFF_LEVEL);
1301 rc = user_len;
1302 goto free_str;
1303 } else {
1304 new_level = debug_get_uint(str);
1305 }
1306 if (new_level < 0) {
1307 pr_warn("%s is not a valid level for a debug feature\n", str);
1308 rc = -EINVAL;
1309 } else {
1310 debug_set_level(id, new_level);
1311 rc = user_len;
1312 }
1313free_str:
1314 kfree(str);
1315out:
1316 *offset += user_len;
1317 return rc; /* number of input characters */
1318}
1319
1320/*
1321 * flushes debug areas
1322 */
1323static void debug_flush(debug_info_t *id, int area)
1324{
1325 unsigned long flags;
1326 int i, j;
1327
1328 if (!id || !id->areas)
1329 return;
1330 spin_lock_irqsave(&id->lock, flags);
1331 if (area == DEBUG_FLUSH_ALL) {
1332 id->active_area = 0;
1333 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1334 for (i = 0; i < id->nr_areas; i++) {
1335 id->active_pages[i] = 0;
1336 for (j = 0; j < id->pages_per_area; j++)
1337 memset(id->areas[i][j], 0, PAGE_SIZE);
1338 }
1339 } else if (area >= 0 && area < id->nr_areas) {
1340 id->active_entries[area] = 0;
1341 id->active_pages[area] = 0;
1342 for (i = 0; i < id->pages_per_area; i++)
1343 memset(id->areas[area][i], 0, PAGE_SIZE);
1344 }
1345 spin_unlock_irqrestore(&id->lock, flags);
1346}
1347
1348/*
1349 * view function: flushes debug areas
1350 */
1351static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1352 struct file *file, const char __user *user_buf,
1353 size_t user_len, loff_t *offset)
1354{
1355 char input_buf[1];
1356 int rc = user_len;
1357
1358 if (user_len > 0x10000)
1359 user_len = 0x10000;
1360 if (*offset != 0) {
1361 rc = -EPIPE;
1362 goto out;
1363 }
1364 if (copy_from_user(input_buf, user_buf, 1)) {
1365 rc = -EFAULT;
1366 goto out;
1367 }
1368 if (input_buf[0] == '-') {
1369 debug_flush(id, DEBUG_FLUSH_ALL);
1370 goto out;
1371 }
1372 if (isdigit(input_buf[0])) {
1373 int area = ((int) input_buf[0] - (int) '0');
1374
1375 debug_flush(id, area);
1376 goto out;
1377 }
1378
1379 pr_info("Flushing debug data failed because %c is not a valid "
1380 "area\n", input_buf[0]);
1381
1382out:
1383 *offset += user_len;
1384 return rc; /* number of input characters */
1385}
1386
1387/*
1388 * prints debug header in raw format
1389 */
1390static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1391 int area, debug_entry_t *entry, char *out_buf)
1392{
1393 int rc;
1394
1395 rc = sizeof(debug_entry_t);
1396 memcpy(out_buf, entry, sizeof(debug_entry_t));
1397 return rc;
1398}
1399
1400/*
1401 * prints debug data in raw format
1402 */
1403static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1404 char *out_buf, const char *in_buf)
1405{
1406 int rc;
1407
1408 rc = id->buf_size;
1409 memcpy(out_buf, in_buf, id->buf_size);
1410 return rc;
1411}
1412
1413/*
1414 * prints debug data in hex/ascii format
1415 */
1416static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1417 char *out_buf, const char *in_buf)
1418{
1419 int i, rc = 0;
1420
1421 for (i = 0; i < id->buf_size; i++)
1422 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1423 rc += sprintf(out_buf + rc, "| ");
1424 for (i = 0; i < id->buf_size; i++) {
1425 unsigned char c = in_buf[i];
1426
1427 if (isascii(c) && isprint(c))
1428 rc += sprintf(out_buf + rc, "%c", c);
1429 else
1430 rc += sprintf(out_buf + rc, ".");
1431 }
1432 rc += sprintf(out_buf + rc, "\n");
1433 return rc;
1434}
1435
1436/*
1437 * prints header for debug entry
1438 */
1439int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1440 int area, debug_entry_t *entry, char *out_buf)
1441{
1442 unsigned long base, sec, usec;
1443 unsigned long caller;
1444 unsigned int level;
1445 char *except_str;
1446 int rc = 0;
1447
1448 level = entry->id.fields.level;
1449 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1450 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1451 usec = do_div(sec, USEC_PER_SEC);
1452
1453 if (entry->id.fields.exception)
1454 except_str = "*";
1455 else
1456 except_str = "-";
1457 caller = (unsigned long) entry->caller;
1458 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1459 area, sec, usec, level, except_str,
1460 entry->id.fields.cpuid, (void *)caller);
1461 return rc;
1462}
1463EXPORT_SYMBOL(debug_dflt_header_fn);
1464
1465/*
1466 * prints debug data sprintf-formated:
1467 * debug_sprinf_event/exception calls must be used together with this view
1468 */
1469
1470#define DEBUG_SPRINTF_MAX_ARGS 10
1471
1472static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1473 char *out_buf, debug_sprintf_entry_t *curr_event)
1474{
1475 int num_longs, num_used_args = 0, i, rc = 0;
1476 int index[DEBUG_SPRINTF_MAX_ARGS];
1477
1478 /* count of longs fit into one entry */
1479 num_longs = id->buf_size / sizeof(long);
1480
1481 if (num_longs < 1)
1482 goto out; /* bufsize of entry too small */
1483 if (num_longs == 1) {
1484 /* no args, we use only the string */
1485 strcpy(out_buf, curr_event->string);
1486 rc = strlen(curr_event->string);
1487 goto out;
1488 }
1489
1490 /* number of arguments used for sprintf (without the format string) */
1491 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1492
1493 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1494
1495 for (i = 0; i < num_used_args; i++)
1496 index[i] = i;
1497
1498 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1499 curr_event->args[index[1]], curr_event->args[index[2]],
1500 curr_event->args[index[3]], curr_event->args[index[4]],
1501 curr_event->args[index[5]], curr_event->args[index[6]],
1502 curr_event->args[index[7]], curr_event->args[index[8]],
1503 curr_event->args[index[9]]);
1504out:
1505 return rc;
1506}
1507
1508/*
1509 * debug_init:
1510 * - is called exactly once to initialize the debug feature
1511 */
1512static int __init debug_init(void)
1513{
1514 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1515 mutex_lock(&debug_mutex);
1516 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1517 initialized = 1;
1518 mutex_unlock(&debug_mutex);
1519 return 0;
1520}
1521postcore_initcall(debug_init);
1/*
2 * S/390 debug facility
3 *
4 * Copyright IBM Corp. 1999, 2012
5 *
6 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
7 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
8 *
9 * Bugreports to: <Linux390@de.ibm.com>
10 */
11
12#define KMSG_COMPONENT "s390dbf"
13#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14
15#include <linux/stddef.h>
16#include <linux/kernel.h>
17#include <linux/errno.h>
18#include <linux/slab.h>
19#include <linux/ctype.h>
20#include <linux/string.h>
21#include <linux/sysctl.h>
22#include <asm/uaccess.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/fs.h>
26#include <linux/debugfs.h>
27
28#include <asm/debug.h>
29
30#define DEBUG_PROLOG_ENTRY -1
31
32#define ALL_AREAS 0 /* copy all debug areas */
33#define NO_AREAS 1 /* copy no debug areas */
34
35/* typedefs */
36
37typedef struct file_private_info {
38 loff_t offset; /* offset of last read in file */
39 int act_area; /* number of last formated area */
40 int act_page; /* act page in given area */
41 int act_entry; /* last formated entry (offset */
42 /* relative to beginning of last */
43 /* formated page) */
44 size_t act_entry_offset; /* up to this offset we copied */
45 /* in last read the last formated */
46 /* entry to userland */
47 char temp_buf[2048]; /* buffer for output */
48 debug_info_t *debug_info_org; /* original debug information */
49 debug_info_t *debug_info_snap; /* snapshot of debug information */
50 struct debug_view *view; /* used view of debug info */
51} file_private_info_t;
52
53typedef struct
54{
55 char *string;
56 /*
57 * This assumes that all args are converted into longs
58 * on L/390 this is the case for all types of parameter
59 * except of floats, and long long (32 bit)
60 *
61 */
62 long args[0];
63} debug_sprintf_entry_t;
64
65
66/* internal function prototyes */
67
68static int debug_init(void);
69static ssize_t debug_output(struct file *file, char __user *user_buf,
70 size_t user_len, loff_t * offset);
71static ssize_t debug_input(struct file *file, const char __user *user_buf,
72 size_t user_len, loff_t * offset);
73static int debug_open(struct inode *inode, struct file *file);
74static int debug_close(struct inode *inode, struct file *file);
75static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76 int nr_areas, int buf_size, umode_t mode);
77static void debug_info_get(debug_info_t *);
78static void debug_info_put(debug_info_t *);
79static int debug_prolog_level_fn(debug_info_t * id,
80 struct debug_view *view, char *out_buf);
81static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
82 struct file *file, const char __user *user_buf,
83 size_t user_buf_size, loff_t * offset);
84static int debug_prolog_pages_fn(debug_info_t * id,
85 struct debug_view *view, char *out_buf);
86static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
87 struct file *file, const char __user *user_buf,
88 size_t user_buf_size, loff_t * offset);
89static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
90 struct file *file, const char __user *user_buf,
91 size_t user_buf_size, loff_t * offset);
92static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93 char *out_buf, const char *in_buf);
94static int debug_raw_format_fn(debug_info_t * id,
95 struct debug_view *view, char *out_buf,
96 const char *in_buf);
97static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98 int area, debug_entry_t * entry, char *out_buf);
99
100static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
101 char *out_buf, debug_sprintf_entry_t *curr_event);
102
103/* globals */
104
105struct debug_view debug_raw_view = {
106 "raw",
107 NULL,
108 &debug_raw_header_fn,
109 &debug_raw_format_fn,
110 NULL,
111 NULL
112};
113EXPORT_SYMBOL(debug_raw_view);
114
115struct debug_view debug_hex_ascii_view = {
116 "hex_ascii",
117 NULL,
118 &debug_dflt_header_fn,
119 &debug_hex_ascii_format_fn,
120 NULL,
121 NULL
122};
123EXPORT_SYMBOL(debug_hex_ascii_view);
124
125static struct debug_view debug_level_view = {
126 "level",
127 &debug_prolog_level_fn,
128 NULL,
129 NULL,
130 &debug_input_level_fn,
131 NULL
132};
133
134static struct debug_view debug_pages_view = {
135 "pages",
136 &debug_prolog_pages_fn,
137 NULL,
138 NULL,
139 &debug_input_pages_fn,
140 NULL
141};
142
143static struct debug_view debug_flush_view = {
144 "flush",
145 NULL,
146 NULL,
147 NULL,
148 &debug_input_flush_fn,
149 NULL
150};
151
152struct debug_view debug_sprintf_view = {
153 "sprintf",
154 NULL,
155 &debug_dflt_header_fn,
156 (debug_format_proc_t*)&debug_sprintf_format_fn,
157 NULL,
158 NULL
159};
160EXPORT_SYMBOL(debug_sprintf_view);
161
162/* used by dump analysis tools to determine version of debug feature */
163static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
164
165/* static globals */
166
167static debug_info_t *debug_area_first = NULL;
168static debug_info_t *debug_area_last = NULL;
169static DEFINE_MUTEX(debug_mutex);
170
171static int initialized;
172static int debug_critical;
173
174static const struct file_operations debug_file_ops = {
175 .owner = THIS_MODULE,
176 .read = debug_output,
177 .write = debug_input,
178 .open = debug_open,
179 .release = debug_close,
180 .llseek = no_llseek,
181};
182
183static struct dentry *debug_debugfs_root_entry;
184
185/* functions */
186
187/*
188 * debug_areas_alloc
189 * - Debug areas are implemented as a threedimensonal array:
190 * areas[areanumber][pagenumber][pageoffset]
191 */
192
193static debug_entry_t***
194debug_areas_alloc(int pages_per_area, int nr_areas)
195{
196 debug_entry_t*** areas;
197 int i,j;
198
199 areas = kmalloc(nr_areas *
200 sizeof(debug_entry_t**),
201 GFP_KERNEL);
202 if (!areas)
203 goto fail_malloc_areas;
204 for (i = 0; i < nr_areas; i++) {
205 areas[i] = kmalloc(pages_per_area *
206 sizeof(debug_entry_t*),GFP_KERNEL);
207 if (!areas[i]) {
208 goto fail_malloc_areas2;
209 }
210 for(j = 0; j < pages_per_area; j++) {
211 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
212 if(!areas[i][j]) {
213 for(j--; j >=0 ; j--) {
214 kfree(areas[i][j]);
215 }
216 kfree(areas[i]);
217 goto fail_malloc_areas2;
218 }
219 }
220 }
221 return areas;
222
223fail_malloc_areas2:
224 for(i--; i >= 0; i--){
225 for(j=0; j < pages_per_area;j++){
226 kfree(areas[i][j]);
227 }
228 kfree(areas[i]);
229 }
230 kfree(areas);
231fail_malloc_areas:
232 return NULL;
233
234}
235
236
237/*
238 * debug_info_alloc
239 * - alloc new debug-info
240 */
241
242static debug_info_t*
243debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
244 int buf_size, int level, int mode)
245{
246 debug_info_t* rc;
247
248 /* alloc everything */
249
250 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
251 if(!rc)
252 goto fail_malloc_rc;
253 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254 if(!rc->active_entries)
255 goto fail_malloc_active_entries;
256 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
257 if(!rc->active_pages)
258 goto fail_malloc_active_pages;
259 if((mode == ALL_AREAS) && (pages_per_area != 0)){
260 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
261 if(!rc->areas)
262 goto fail_malloc_areas;
263 } else {
264 rc->areas = NULL;
265 }
266
267 /* initialize members */
268
269 spin_lock_init(&rc->lock);
270 rc->pages_per_area = pages_per_area;
271 rc->nr_areas = nr_areas;
272 rc->active_area = 0;
273 rc->level = level;
274 rc->buf_size = buf_size;
275 rc->entry_size = sizeof(debug_entry_t) + buf_size;
276 strlcpy(rc->name, name, sizeof(rc->name));
277 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
278 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
279 sizeof(struct dentry*));
280 atomic_set(&(rc->ref_count), 0);
281
282 return rc;
283
284fail_malloc_areas:
285 kfree(rc->active_pages);
286fail_malloc_active_pages:
287 kfree(rc->active_entries);
288fail_malloc_active_entries:
289 kfree(rc);
290fail_malloc_rc:
291 return NULL;
292}
293
294/*
295 * debug_areas_free
296 * - free all debug areas
297 */
298
299static void
300debug_areas_free(debug_info_t* db_info)
301{
302 int i,j;
303
304 if(!db_info->areas)
305 return;
306 for (i = 0; i < db_info->nr_areas; i++) {
307 for(j = 0; j < db_info->pages_per_area; j++) {
308 kfree(db_info->areas[i][j]);
309 }
310 kfree(db_info->areas[i]);
311 }
312 kfree(db_info->areas);
313 db_info->areas = NULL;
314}
315
316/*
317 * debug_info_free
318 * - free memory debug-info
319 */
320
321static void
322debug_info_free(debug_info_t* db_info){
323 debug_areas_free(db_info);
324 kfree(db_info->active_entries);
325 kfree(db_info->active_pages);
326 kfree(db_info);
327}
328
329/*
330 * debug_info_create
331 * - create new debug-info
332 */
333
334static debug_info_t*
335debug_info_create(const char *name, int pages_per_area, int nr_areas,
336 int buf_size, umode_t mode)
337{
338 debug_info_t* rc;
339
340 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
341 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
342 if(!rc)
343 goto out;
344
345 rc->mode = mode & ~S_IFMT;
346
347 /* create root directory */
348 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
349 debug_debugfs_root_entry);
350
351 /* append new element to linked list */
352 if (!debug_area_first) {
353 /* first element in list */
354 debug_area_first = rc;
355 rc->prev = NULL;
356 } else {
357 /* append element to end of list */
358 debug_area_last->next = rc;
359 rc->prev = debug_area_last;
360 }
361 debug_area_last = rc;
362 rc->next = NULL;
363
364 debug_info_get(rc);
365out:
366 return rc;
367}
368
369/*
370 * debug_info_copy
371 * - copy debug-info
372 */
373
374static debug_info_t*
375debug_info_copy(debug_info_t* in, int mode)
376{
377 int i,j;
378 debug_info_t* rc;
379 unsigned long flags;
380
381 /* get a consistent copy of the debug areas */
382 do {
383 rc = debug_info_alloc(in->name, in->pages_per_area,
384 in->nr_areas, in->buf_size, in->level, mode);
385 spin_lock_irqsave(&in->lock, flags);
386 if(!rc)
387 goto out;
388 /* has something changed in the meantime ? */
389 if((rc->pages_per_area == in->pages_per_area) &&
390 (rc->nr_areas == in->nr_areas)) {
391 break;
392 }
393 spin_unlock_irqrestore(&in->lock, flags);
394 debug_info_free(rc);
395 } while (1);
396
397 if (mode == NO_AREAS)
398 goto out;
399
400 for(i = 0; i < in->nr_areas; i++){
401 for(j = 0; j < in->pages_per_area; j++) {
402 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
403 }
404 }
405out:
406 spin_unlock_irqrestore(&in->lock, flags);
407 return rc;
408}
409
410/*
411 * debug_info_get
412 * - increments reference count for debug-info
413 */
414
415static void
416debug_info_get(debug_info_t * db_info)
417{
418 if (db_info)
419 atomic_inc(&db_info->ref_count);
420}
421
422/*
423 * debug_info_put:
424 * - decreases reference count for debug-info and frees it if necessary
425 */
426
427static void
428debug_info_put(debug_info_t *db_info)
429{
430 int i;
431
432 if (!db_info)
433 return;
434 if (atomic_dec_and_test(&db_info->ref_count)) {
435 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
436 if (!db_info->views[i])
437 continue;
438 debugfs_remove(db_info->debugfs_entries[i]);
439 }
440 debugfs_remove(db_info->debugfs_root_entry);
441 if(db_info == debug_area_first)
442 debug_area_first = db_info->next;
443 if(db_info == debug_area_last)
444 debug_area_last = db_info->prev;
445 if(db_info->prev) db_info->prev->next = db_info->next;
446 if(db_info->next) db_info->next->prev = db_info->prev;
447 debug_info_free(db_info);
448 }
449}
450
451/*
452 * debug_format_entry:
453 * - format one debug entry and return size of formated data
454 */
455
456static int
457debug_format_entry(file_private_info_t *p_info)
458{
459 debug_info_t *id_snap = p_info->debug_info_snap;
460 struct debug_view *view = p_info->view;
461 debug_entry_t *act_entry;
462 size_t len = 0;
463 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
464 /* print prolog */
465 if (view->prolog_proc)
466 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
467 goto out;
468 }
469 if (!id_snap->areas) /* this is true, if we have a prolog only view */
470 goto out; /* or if 'pages_per_area' is 0 */
471 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
472 [p_info->act_page] + p_info->act_entry);
473
474 if (act_entry->id.stck == 0LL)
475 goto out; /* empty entry */
476 if (view->header_proc)
477 len += view->header_proc(id_snap, view, p_info->act_area,
478 act_entry, p_info->temp_buf + len);
479 if (view->format_proc)
480 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
481 DEBUG_DATA(act_entry));
482out:
483 return len;
484}
485
486/*
487 * debug_next_entry:
488 * - goto next entry in p_info
489 */
490
491static inline int
492debug_next_entry(file_private_info_t *p_info)
493{
494 debug_info_t *id;
495
496 id = p_info->debug_info_snap;
497 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
498 p_info->act_entry = 0;
499 p_info->act_page = 0;
500 goto out;
501 }
502 if(!id->areas)
503 return 1;
504 p_info->act_entry += id->entry_size;
505 /* switch to next page, if we reached the end of the page */
506 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
507 /* next page */
508 p_info->act_entry = 0;
509 p_info->act_page += 1;
510 if((p_info->act_page % id->pages_per_area) == 0) {
511 /* next area */
512 p_info->act_area++;
513 p_info->act_page=0;
514 }
515 if(p_info->act_area >= id->nr_areas)
516 return 1;
517 }
518out:
519 return 0;
520}
521
522/*
523 * debug_output:
524 * - called for user read()
525 * - copies formated debug entries to the user buffer
526 */
527
528static ssize_t
529debug_output(struct file *file, /* file descriptor */
530 char __user *user_buf, /* user buffer */
531 size_t len, /* length of buffer */
532 loff_t *offset) /* offset in the file */
533{
534 size_t count = 0;
535 size_t entry_offset;
536 file_private_info_t *p_info;
537
538 p_info = ((file_private_info_t *) file->private_data);
539 if (*offset != p_info->offset)
540 return -EPIPE;
541 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
542 return 0;
543 entry_offset = p_info->act_entry_offset;
544 while(count < len){
545 int formatted_line_size;
546 int formatted_line_residue;
547 int user_buf_residue;
548 size_t copy_size;
549
550 formatted_line_size = debug_format_entry(p_info);
551 formatted_line_residue = formatted_line_size - entry_offset;
552 user_buf_residue = len-count;
553 copy_size = min(user_buf_residue, formatted_line_residue);
554 if(copy_size){
555 if (copy_to_user(user_buf + count, p_info->temp_buf
556 + entry_offset, copy_size))
557 return -EFAULT;
558 count += copy_size;
559 entry_offset += copy_size;
560 }
561 if(copy_size == formatted_line_residue){
562 entry_offset = 0;
563 if(debug_next_entry(p_info))
564 goto out;
565 }
566 }
567out:
568 p_info->offset = *offset + count;
569 p_info->act_entry_offset = entry_offset;
570 *offset = p_info->offset;
571 return count;
572}
573
574/*
575 * debug_input:
576 * - called for user write()
577 * - calls input function of view
578 */
579
580static ssize_t
581debug_input(struct file *file, const char __user *user_buf, size_t length,
582 loff_t *offset)
583{
584 int rc = 0;
585 file_private_info_t *p_info;
586
587 mutex_lock(&debug_mutex);
588 p_info = ((file_private_info_t *) file->private_data);
589 if (p_info->view->input_proc)
590 rc = p_info->view->input_proc(p_info->debug_info_org,
591 p_info->view, file, user_buf,
592 length, offset);
593 else
594 rc = -EPERM;
595 mutex_unlock(&debug_mutex);
596 return rc; /* number of input characters */
597}
598
599/*
600 * debug_open:
601 * - called for user open()
602 * - copies formated output to private_data area of the file
603 * handle
604 */
605
606static int
607debug_open(struct inode *inode, struct file *file)
608{
609 int i, rc = 0;
610 file_private_info_t *p_info;
611 debug_info_t *debug_info, *debug_info_snapshot;
612
613 mutex_lock(&debug_mutex);
614 debug_info = file_inode(file)->i_private;
615 /* find debug view */
616 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
617 if (!debug_info->views[i])
618 continue;
619 else if (debug_info->debugfs_entries[i] ==
620 file->f_path.dentry) {
621 goto found; /* found view ! */
622 }
623 }
624 /* no entry found */
625 rc = -EINVAL;
626 goto out;
627
628found:
629
630 /* Make snapshot of current debug areas to get it consistent. */
631 /* To copy all the areas is only needed, if we have a view which */
632 /* formats the debug areas. */
633
634 if(!debug_info->views[i]->format_proc &&
635 !debug_info->views[i]->header_proc){
636 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
637 } else {
638 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
639 }
640
641 if(!debug_info_snapshot){
642 rc = -ENOMEM;
643 goto out;
644 }
645 p_info = kmalloc(sizeof(file_private_info_t),
646 GFP_KERNEL);
647 if(!p_info){
648 debug_info_free(debug_info_snapshot);
649 rc = -ENOMEM;
650 goto out;
651 }
652 p_info->offset = 0;
653 p_info->debug_info_snap = debug_info_snapshot;
654 p_info->debug_info_org = debug_info;
655 p_info->view = debug_info->views[i];
656 p_info->act_area = 0;
657 p_info->act_page = 0;
658 p_info->act_entry = DEBUG_PROLOG_ENTRY;
659 p_info->act_entry_offset = 0;
660 file->private_data = p_info;
661 debug_info_get(debug_info);
662 nonseekable_open(inode, file);
663out:
664 mutex_unlock(&debug_mutex);
665 return rc;
666}
667
668/*
669 * debug_close:
670 * - called for user close()
671 * - deletes private_data area of the file handle
672 */
673
674static int
675debug_close(struct inode *inode, struct file *file)
676{
677 file_private_info_t *p_info;
678 p_info = (file_private_info_t *) file->private_data;
679 if(p_info->debug_info_snap)
680 debug_info_free(p_info->debug_info_snap);
681 debug_info_put(p_info->debug_info_org);
682 kfree(file->private_data);
683 return 0; /* success */
684}
685
686/*
687 * debug_register_mode:
688 * - Creates and initializes debug area for the caller
689 * The mode parameter allows to specify access rights for the s390dbf files
690 * - Returns handle for debug area
691 */
692
693debug_info_t *debug_register_mode(const char *name, int pages_per_area,
694 int nr_areas, int buf_size, umode_t mode,
695 uid_t uid, gid_t gid)
696{
697 debug_info_t *rc = NULL;
698
699 /* Since debugfs currently does not support uid/gid other than root, */
700 /* we do not allow gid/uid != 0 until we get support for that. */
701 if ((uid != 0) || (gid != 0))
702 pr_warning("Root becomes the owner of all s390dbf files "
703 "in sysfs\n");
704 BUG_ON(!initialized);
705 mutex_lock(&debug_mutex);
706
707 /* create new debug_info */
708
709 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
710 if(!rc)
711 goto out;
712 debug_register_view(rc, &debug_level_view);
713 debug_register_view(rc, &debug_flush_view);
714 debug_register_view(rc, &debug_pages_view);
715out:
716 if (!rc){
717 pr_err("Registering debug feature %s failed\n", name);
718 }
719 mutex_unlock(&debug_mutex);
720 return rc;
721}
722EXPORT_SYMBOL(debug_register_mode);
723
724/*
725 * debug_register:
726 * - creates and initializes debug area for the caller
727 * - returns handle for debug area
728 */
729
730debug_info_t *debug_register(const char *name, int pages_per_area,
731 int nr_areas, int buf_size)
732{
733 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
734 S_IRUSR | S_IWUSR, 0, 0);
735}
736EXPORT_SYMBOL(debug_register);
737
738/*
739 * debug_unregister:
740 * - give back debug area
741 */
742
743void
744debug_unregister(debug_info_t * id)
745{
746 if (!id)
747 goto out;
748 mutex_lock(&debug_mutex);
749 debug_info_put(id);
750 mutex_unlock(&debug_mutex);
751
752out:
753 return;
754}
755EXPORT_SYMBOL(debug_unregister);
756
757/*
758 * debug_set_size:
759 * - set area size (number of pages) and number of areas
760 */
761static int
762debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
763{
764 unsigned long flags;
765 debug_entry_t *** new_areas;
766 int rc=0;
767
768 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
769 return -EINVAL;
770 if(pages_per_area > 0){
771 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
772 if(!new_areas) {
773 pr_info("Allocating memory for %i pages failed\n",
774 pages_per_area);
775 rc = -ENOMEM;
776 goto out;
777 }
778 } else {
779 new_areas = NULL;
780 }
781 spin_lock_irqsave(&id->lock,flags);
782 debug_areas_free(id);
783 id->areas = new_areas;
784 id->nr_areas = nr_areas;
785 id->pages_per_area = pages_per_area;
786 id->active_area = 0;
787 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
788 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
789 spin_unlock_irqrestore(&id->lock,flags);
790 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
791out:
792 return rc;
793}
794
795/*
796 * debug_set_level:
797 * - set actual debug level
798 */
799
800void
801debug_set_level(debug_info_t* id, int new_level)
802{
803 unsigned long flags;
804 if(!id)
805 return;
806 spin_lock_irqsave(&id->lock,flags);
807 if(new_level == DEBUG_OFF_LEVEL){
808 id->level = DEBUG_OFF_LEVEL;
809 pr_info("%s: switched off\n",id->name);
810 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
811 pr_info("%s: level %i is out of range (%i - %i)\n",
812 id->name, new_level, 0, DEBUG_MAX_LEVEL);
813 } else {
814 id->level = new_level;
815 }
816 spin_unlock_irqrestore(&id->lock,flags);
817}
818EXPORT_SYMBOL(debug_set_level);
819
820/*
821 * proceed_active_entry:
822 * - set active entry to next in the ring buffer
823 */
824
825static inline void
826proceed_active_entry(debug_info_t * id)
827{
828 if ((id->active_entries[id->active_area] += id->entry_size)
829 > (PAGE_SIZE - id->entry_size)){
830 id->active_entries[id->active_area] = 0;
831 id->active_pages[id->active_area] =
832 (id->active_pages[id->active_area] + 1) %
833 id->pages_per_area;
834 }
835}
836
837/*
838 * proceed_active_area:
839 * - set active area to next in the ring buffer
840 */
841
842static inline void
843proceed_active_area(debug_info_t * id)
844{
845 id->active_area++;
846 id->active_area = id->active_area % id->nr_areas;
847}
848
849/*
850 * get_active_entry:
851 */
852
853static inline debug_entry_t*
854get_active_entry(debug_info_t * id)
855{
856 return (debug_entry_t *) (((char *) id->areas[id->active_area]
857 [id->active_pages[id->active_area]]) +
858 id->active_entries[id->active_area]);
859}
860
861/*
862 * debug_finish_entry:
863 * - set timestamp, caller address, cpu number etc.
864 */
865
866static inline void
867debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
868 int exception)
869{
870 active->id.stck = get_tod_clock_fast();
871 active->id.fields.cpuid = smp_processor_id();
872 active->caller = __builtin_return_address(0);
873 active->id.fields.exception = exception;
874 active->id.fields.level = level;
875 proceed_active_entry(id);
876 if(exception)
877 proceed_active_area(id);
878}
879
880static int debug_stoppable=1;
881static int debug_active=1;
882
883#define CTL_S390DBF_STOPPABLE 5678
884#define CTL_S390DBF_ACTIVE 5679
885
886/*
887 * proc handler for the running debug_active sysctl
888 * always allow read, allow write only if debug_stoppable is set or
889 * if debug_active is already off
890 */
891static int
892s390dbf_procactive(struct ctl_table *table, int write,
893 void __user *buffer, size_t *lenp, loff_t *ppos)
894{
895 if (!write || debug_stoppable || !debug_active)
896 return proc_dointvec(table, write, buffer, lenp, ppos);
897 else
898 return 0;
899}
900
901
902static struct ctl_table s390dbf_table[] = {
903 {
904 .procname = "debug_stoppable",
905 .data = &debug_stoppable,
906 .maxlen = sizeof(int),
907 .mode = S_IRUGO | S_IWUSR,
908 .proc_handler = proc_dointvec,
909 },
910 {
911 .procname = "debug_active",
912 .data = &debug_active,
913 .maxlen = sizeof(int),
914 .mode = S_IRUGO | S_IWUSR,
915 .proc_handler = s390dbf_procactive,
916 },
917 { }
918};
919
920static struct ctl_table s390dbf_dir_table[] = {
921 {
922 .procname = "s390dbf",
923 .maxlen = 0,
924 .mode = S_IRUGO | S_IXUGO,
925 .child = s390dbf_table,
926 },
927 { }
928};
929
930static struct ctl_table_header *s390dbf_sysctl_header;
931
932void
933debug_stop_all(void)
934{
935 if (debug_stoppable)
936 debug_active = 0;
937}
938EXPORT_SYMBOL(debug_stop_all);
939
940void debug_set_critical(void)
941{
942 debug_critical = 1;
943}
944
945/*
946 * debug_event_common:
947 * - write debug entry with given size
948 */
949
950debug_entry_t*
951debug_event_common(debug_info_t * id, int level, const void *buf, int len)
952{
953 unsigned long flags;
954 debug_entry_t *active;
955
956 if (!debug_active || !id->areas)
957 return NULL;
958 if (debug_critical) {
959 if (!spin_trylock_irqsave(&id->lock, flags))
960 return NULL;
961 } else
962 spin_lock_irqsave(&id->lock, flags);
963 active = get_active_entry(id);
964 memset(DEBUG_DATA(active), 0, id->buf_size);
965 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
966 debug_finish_entry(id, active, level, 0);
967 spin_unlock_irqrestore(&id->lock, flags);
968
969 return active;
970}
971EXPORT_SYMBOL(debug_event_common);
972
973/*
974 * debug_exception_common:
975 * - write debug entry with given size and switch to next debug area
976 */
977
978debug_entry_t
979*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
980{
981 unsigned long flags;
982 debug_entry_t *active;
983
984 if (!debug_active || !id->areas)
985 return NULL;
986 if (debug_critical) {
987 if (!spin_trylock_irqsave(&id->lock, flags))
988 return NULL;
989 } else
990 spin_lock_irqsave(&id->lock, flags);
991 active = get_active_entry(id);
992 memset(DEBUG_DATA(active), 0, id->buf_size);
993 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
994 debug_finish_entry(id, active, level, 1);
995 spin_unlock_irqrestore(&id->lock, flags);
996
997 return active;
998}
999EXPORT_SYMBOL(debug_exception_common);
1000
1001/*
1002 * counts arguments in format string for sprintf view
1003 */
1004
1005static inline int
1006debug_count_numargs(char *string)
1007{
1008 int numargs=0;
1009
1010 while(*string) {
1011 if(*string++=='%')
1012 numargs++;
1013 }
1014 return(numargs);
1015}
1016
1017/*
1018 * debug_sprintf_event:
1019 */
1020
1021debug_entry_t*
1022debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1023{
1024 va_list ap;
1025 int numargs,idx;
1026 unsigned long flags;
1027 debug_sprintf_entry_t *curr_event;
1028 debug_entry_t *active;
1029
1030 if((!id) || (level > id->level))
1031 return NULL;
1032 if (!debug_active || !id->areas)
1033 return NULL;
1034 numargs=debug_count_numargs(string);
1035
1036 if (debug_critical) {
1037 if (!spin_trylock_irqsave(&id->lock, flags))
1038 return NULL;
1039 } else
1040 spin_lock_irqsave(&id->lock, flags);
1041 active = get_active_entry(id);
1042 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1043 va_start(ap,string);
1044 curr_event->string=string;
1045 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1046 curr_event->args[idx]=va_arg(ap,long);
1047 va_end(ap);
1048 debug_finish_entry(id, active, level, 0);
1049 spin_unlock_irqrestore(&id->lock, flags);
1050
1051 return active;
1052}
1053EXPORT_SYMBOL(debug_sprintf_event);
1054
1055/*
1056 * debug_sprintf_exception:
1057 */
1058
1059debug_entry_t*
1060debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1061{
1062 va_list ap;
1063 int numargs,idx;
1064 unsigned long flags;
1065 debug_sprintf_entry_t *curr_event;
1066 debug_entry_t *active;
1067
1068 if((!id) || (level > id->level))
1069 return NULL;
1070 if (!debug_active || !id->areas)
1071 return NULL;
1072
1073 numargs=debug_count_numargs(string);
1074
1075 if (debug_critical) {
1076 if (!spin_trylock_irqsave(&id->lock, flags))
1077 return NULL;
1078 } else
1079 spin_lock_irqsave(&id->lock, flags);
1080 active = get_active_entry(id);
1081 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1082 va_start(ap,string);
1083 curr_event->string=string;
1084 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1085 curr_event->args[idx]=va_arg(ap,long);
1086 va_end(ap);
1087 debug_finish_entry(id, active, level, 1);
1088 spin_unlock_irqrestore(&id->lock, flags);
1089
1090 return active;
1091}
1092EXPORT_SYMBOL(debug_sprintf_exception);
1093
1094/*
1095 * debug_register_view:
1096 */
1097
1098int
1099debug_register_view(debug_info_t * id, struct debug_view *view)
1100{
1101 int rc = 0;
1102 int i;
1103 unsigned long flags;
1104 umode_t mode;
1105 struct dentry *pde;
1106
1107 if (!id)
1108 goto out;
1109 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1110 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1111 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1112 if (!view->input_proc)
1113 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1114 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1115 id , &debug_file_ops);
1116 if (!pde){
1117 pr_err("Registering view %s/%s failed due to out of "
1118 "memory\n", id->name,view->name);
1119 rc = -1;
1120 goto out;
1121 }
1122 spin_lock_irqsave(&id->lock, flags);
1123 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1124 if (!id->views[i])
1125 break;
1126 }
1127 if (i == DEBUG_MAX_VIEWS) {
1128 pr_err("Registering view %s/%s would exceed the maximum "
1129 "number of views %i\n", id->name, view->name, i);
1130 rc = -1;
1131 } else {
1132 id->views[i] = view;
1133 id->debugfs_entries[i] = pde;
1134 }
1135 spin_unlock_irqrestore(&id->lock, flags);
1136 if (rc)
1137 debugfs_remove(pde);
1138out:
1139 return rc;
1140}
1141EXPORT_SYMBOL(debug_register_view);
1142
1143/*
1144 * debug_unregister_view:
1145 */
1146
1147int
1148debug_unregister_view(debug_info_t * id, struct debug_view *view)
1149{
1150 struct dentry *dentry = NULL;
1151 unsigned long flags;
1152 int i, rc = 0;
1153
1154 if (!id)
1155 goto out;
1156 spin_lock_irqsave(&id->lock, flags);
1157 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1158 if (id->views[i] == view)
1159 break;
1160 }
1161 if (i == DEBUG_MAX_VIEWS)
1162 rc = -1;
1163 else {
1164 dentry = id->debugfs_entries[i];
1165 id->views[i] = NULL;
1166 id->debugfs_entries[i] = NULL;
1167 }
1168 spin_unlock_irqrestore(&id->lock, flags);
1169 debugfs_remove(dentry);
1170out:
1171 return rc;
1172}
1173EXPORT_SYMBOL(debug_unregister_view);
1174
1175static inline char *
1176debug_get_user_string(const char __user *user_buf, size_t user_len)
1177{
1178 char* buffer;
1179
1180 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1181 if (!buffer)
1182 return ERR_PTR(-ENOMEM);
1183 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1184 kfree(buffer);
1185 return ERR_PTR(-EFAULT);
1186 }
1187 /* got the string, now strip linefeed. */
1188 if (buffer[user_len - 1] == '\n')
1189 buffer[user_len - 1] = 0;
1190 else
1191 buffer[user_len] = 0;
1192 return buffer;
1193}
1194
1195static inline int
1196debug_get_uint(char *buf)
1197{
1198 int rc;
1199
1200 buf = skip_spaces(buf);
1201 rc = simple_strtoul(buf, &buf, 10);
1202 if(*buf){
1203 rc = -EINVAL;
1204 }
1205 return rc;
1206}
1207
1208/*
1209 * functions for debug-views
1210 ***********************************
1211*/
1212
1213/*
1214 * prints out actual debug level
1215 */
1216
1217static int
1218debug_prolog_pages_fn(debug_info_t * id,
1219 struct debug_view *view, char *out_buf)
1220{
1221 return sprintf(out_buf, "%i\n", id->pages_per_area);
1222}
1223
1224/*
1225 * reads new size (number of pages per debug area)
1226 */
1227
1228static int
1229debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1230 struct file *file, const char __user *user_buf,
1231 size_t user_len, loff_t * offset)
1232{
1233 char *str;
1234 int rc,new_pages;
1235
1236 if (user_len > 0x10000)
1237 user_len = 0x10000;
1238 if (*offset != 0){
1239 rc = -EPIPE;
1240 goto out;
1241 }
1242 str = debug_get_user_string(user_buf,user_len);
1243 if(IS_ERR(str)){
1244 rc = PTR_ERR(str);
1245 goto out;
1246 }
1247 new_pages = debug_get_uint(str);
1248 if(new_pages < 0){
1249 rc = -EINVAL;
1250 goto free_str;
1251 }
1252 rc = debug_set_size(id,id->nr_areas, new_pages);
1253 if(rc != 0){
1254 rc = -EINVAL;
1255 goto free_str;
1256 }
1257 rc = user_len;
1258free_str:
1259 kfree(str);
1260out:
1261 *offset += user_len;
1262 return rc; /* number of input characters */
1263}
1264
1265/*
1266 * prints out actual debug level
1267 */
1268
1269static int
1270debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1271{
1272 int rc = 0;
1273
1274 if(id->level == DEBUG_OFF_LEVEL) {
1275 rc = sprintf(out_buf,"-\n");
1276 }
1277 else {
1278 rc = sprintf(out_buf, "%i\n", id->level);
1279 }
1280 return rc;
1281}
1282
1283/*
1284 * reads new debug level
1285 */
1286
1287static int
1288debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1289 struct file *file, const char __user *user_buf,
1290 size_t user_len, loff_t * offset)
1291{
1292 char *str;
1293 int rc,new_level;
1294
1295 if (user_len > 0x10000)
1296 user_len = 0x10000;
1297 if (*offset != 0){
1298 rc = -EPIPE;
1299 goto out;
1300 }
1301 str = debug_get_user_string(user_buf,user_len);
1302 if(IS_ERR(str)){
1303 rc = PTR_ERR(str);
1304 goto out;
1305 }
1306 if(str[0] == '-'){
1307 debug_set_level(id, DEBUG_OFF_LEVEL);
1308 rc = user_len;
1309 goto free_str;
1310 } else {
1311 new_level = debug_get_uint(str);
1312 }
1313 if(new_level < 0) {
1314 pr_warning("%s is not a valid level for a debug "
1315 "feature\n", str);
1316 rc = -EINVAL;
1317 } else {
1318 debug_set_level(id, new_level);
1319 rc = user_len;
1320 }
1321free_str:
1322 kfree(str);
1323out:
1324 *offset += user_len;
1325 return rc; /* number of input characters */
1326}
1327
1328
1329/*
1330 * flushes debug areas
1331 */
1332
1333static void debug_flush(debug_info_t* id, int area)
1334{
1335 unsigned long flags;
1336 int i,j;
1337
1338 if(!id || !id->areas)
1339 return;
1340 spin_lock_irqsave(&id->lock,flags);
1341 if(area == DEBUG_FLUSH_ALL){
1342 id->active_area = 0;
1343 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1344 for (i = 0; i < id->nr_areas; i++) {
1345 id->active_pages[i] = 0;
1346 for(j = 0; j < id->pages_per_area; j++) {
1347 memset(id->areas[i][j], 0, PAGE_SIZE);
1348 }
1349 }
1350 } else if(area >= 0 && area < id->nr_areas) {
1351 id->active_entries[area] = 0;
1352 id->active_pages[area] = 0;
1353 for(i = 0; i < id->pages_per_area; i++) {
1354 memset(id->areas[area][i],0,PAGE_SIZE);
1355 }
1356 }
1357 spin_unlock_irqrestore(&id->lock,flags);
1358}
1359
1360/*
1361 * view function: flushes debug areas
1362 */
1363
1364static int
1365debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1366 struct file *file, const char __user *user_buf,
1367 size_t user_len, loff_t * offset)
1368{
1369 char input_buf[1];
1370 int rc = user_len;
1371
1372 if (user_len > 0x10000)
1373 user_len = 0x10000;
1374 if (*offset != 0){
1375 rc = -EPIPE;
1376 goto out;
1377 }
1378 if (copy_from_user(input_buf, user_buf, 1)){
1379 rc = -EFAULT;
1380 goto out;
1381 }
1382 if(input_buf[0] == '-') {
1383 debug_flush(id, DEBUG_FLUSH_ALL);
1384 goto out;
1385 }
1386 if (isdigit(input_buf[0])) {
1387 int area = ((int) input_buf[0] - (int) '0');
1388 debug_flush(id, area);
1389 goto out;
1390 }
1391
1392 pr_info("Flushing debug data failed because %c is not a valid "
1393 "area\n", input_buf[0]);
1394
1395out:
1396 *offset += user_len;
1397 return rc; /* number of input characters */
1398}
1399
1400/*
1401 * prints debug header in raw format
1402 */
1403
1404static int
1405debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1406 int area, debug_entry_t * entry, char *out_buf)
1407{
1408 int rc;
1409
1410 rc = sizeof(debug_entry_t);
1411 memcpy(out_buf,entry,sizeof(debug_entry_t));
1412 return rc;
1413}
1414
1415/*
1416 * prints debug data in raw format
1417 */
1418
1419static int
1420debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1421 char *out_buf, const char *in_buf)
1422{
1423 int rc;
1424
1425 rc = id->buf_size;
1426 memcpy(out_buf, in_buf, id->buf_size);
1427 return rc;
1428}
1429
1430/*
1431 * prints debug data in hex/ascii format
1432 */
1433
1434static int
1435debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1436 char *out_buf, const char *in_buf)
1437{
1438 int i, rc = 0;
1439
1440 for (i = 0; i < id->buf_size; i++) {
1441 rc += sprintf(out_buf + rc, "%02x ",
1442 ((unsigned char *) in_buf)[i]);
1443 }
1444 rc += sprintf(out_buf + rc, "| ");
1445 for (i = 0; i < id->buf_size; i++) {
1446 unsigned char c = in_buf[i];
1447 if (isascii(c) && isprint(c))
1448 rc += sprintf(out_buf + rc, "%c", c);
1449 else
1450 rc += sprintf(out_buf + rc, ".");
1451 }
1452 rc += sprintf(out_buf + rc, "\n");
1453 return rc;
1454}
1455
1456/*
1457 * prints header for debug entry
1458 */
1459
1460int
1461debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1462 int area, debug_entry_t * entry, char *out_buf)
1463{
1464 struct timespec time_spec;
1465 char *except_str;
1466 unsigned long caller;
1467 int rc = 0;
1468 unsigned int level;
1469
1470 level = entry->id.fields.level;
1471 stck_to_timespec(entry->id.stck, &time_spec);
1472
1473 if (entry->id.fields.exception)
1474 except_str = "*";
1475 else
1476 except_str = "-";
1477 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1478 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1479 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1480 except_str, entry->id.fields.cpuid, (void *) caller);
1481 return rc;
1482}
1483EXPORT_SYMBOL(debug_dflt_header_fn);
1484
1485/*
1486 * prints debug data sprintf-formated:
1487 * debug_sprinf_event/exception calls must be used together with this view
1488 */
1489
1490#define DEBUG_SPRINTF_MAX_ARGS 10
1491
1492static int
1493debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1494 char *out_buf, debug_sprintf_entry_t *curr_event)
1495{
1496 int num_longs, num_used_args = 0,i, rc = 0;
1497 int index[DEBUG_SPRINTF_MAX_ARGS];
1498
1499 /* count of longs fit into one entry */
1500 num_longs = id->buf_size / sizeof(long);
1501
1502 if(num_longs < 1)
1503 goto out; /* bufsize of entry too small */
1504 if(num_longs == 1) {
1505 /* no args, we use only the string */
1506 strcpy(out_buf, curr_event->string);
1507 rc = strlen(curr_event->string);
1508 goto out;
1509 }
1510
1511 /* number of arguments used for sprintf (without the format string) */
1512 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1513
1514 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1515
1516 for(i = 0; i < num_used_args; i++)
1517 index[i] = i;
1518
1519 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1520 curr_event->args[index[1]], curr_event->args[index[2]],
1521 curr_event->args[index[3]], curr_event->args[index[4]],
1522 curr_event->args[index[5]], curr_event->args[index[6]],
1523 curr_event->args[index[7]], curr_event->args[index[8]],
1524 curr_event->args[index[9]]);
1525
1526out:
1527
1528 return rc;
1529}
1530
1531/*
1532 * debug_init:
1533 * - is called exactly once to initialize the debug feature
1534 */
1535static int __init debug_init(void)
1536{
1537 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1538 mutex_lock(&debug_mutex);
1539 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1540 initialized = 1;
1541 mutex_unlock(&debug_mutex);
1542 return 0;
1543}
1544postcore_initcall(debug_init);