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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(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(pages_per_area * sizeof(debug_entry_t *), GFP_KERNEL);
202 if (!areas[i])
203 goto fail_malloc_areas2;
204 for (j = 0; j < pages_per_area; j++) {
205 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
206 if (!areas[i][j]) {
207 for (j--; j >= 0 ; j--)
208 kfree(areas[i][j]);
209 kfree(areas[i]);
210 goto fail_malloc_areas2;
211 }
212 }
213 }
214 return areas;
215
216fail_malloc_areas2:
217 for (i--; i >= 0; i--) {
218 for (j = 0; j < pages_per_area; j++)
219 kfree(areas[i][j]);
220 kfree(areas[i]);
221 }
222 kfree(areas);
223fail_malloc_areas:
224 return NULL;
225}
226
227/*
228 * debug_info_alloc
229 * - alloc new debug-info
230 */
231static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
232 int nr_areas, int buf_size, int level,
233 int mode)
234{
235 debug_info_t *rc;
236
237 /* alloc everything */
238 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
239 if (!rc)
240 goto fail_malloc_rc;
241 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
242 if (!rc->active_entries)
243 goto fail_malloc_active_entries;
244 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
245 if (!rc->active_pages)
246 goto fail_malloc_active_pages;
247 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
248 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
249 if (!rc->areas)
250 goto fail_malloc_areas;
251 } else {
252 rc->areas = NULL;
253 }
254
255 /* initialize members */
256 spin_lock_init(&rc->lock);
257 rc->pages_per_area = pages_per_area;
258 rc->nr_areas = nr_areas;
259 rc->active_area = 0;
260 rc->level = level;
261 rc->buf_size = buf_size;
262 rc->entry_size = sizeof(debug_entry_t) + buf_size;
263 strlcpy(rc->name, name, sizeof(rc->name));
264 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
265 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
266 refcount_set(&(rc->ref_count), 0);
267
268 return rc;
269
270fail_malloc_areas:
271 kfree(rc->active_pages);
272fail_malloc_active_pages:
273 kfree(rc->active_entries);
274fail_malloc_active_entries:
275 kfree(rc);
276fail_malloc_rc:
277 return NULL;
278}
279
280/*
281 * debug_areas_free
282 * - free all debug areas
283 */
284static void debug_areas_free(debug_info_t *db_info)
285{
286 int i, j;
287
288 if (!db_info->areas)
289 return;
290 for (i = 0; i < db_info->nr_areas; i++) {
291 for (j = 0; j < db_info->pages_per_area; j++)
292 kfree(db_info->areas[i][j]);
293 kfree(db_info->areas[i]);
294 }
295 kfree(db_info->areas);
296 db_info->areas = NULL;
297}
298
299/*
300 * debug_info_free
301 * - free memory debug-info
302 */
303static void debug_info_free(debug_info_t *db_info)
304{
305 debug_areas_free(db_info);
306 kfree(db_info->active_entries);
307 kfree(db_info->active_pages);
308 kfree(db_info);
309}
310
311/*
312 * debug_info_create
313 * - create new debug-info
314 */
315
316static debug_info_t *debug_info_create(const char *name, int pages_per_area,
317 int nr_areas, int buf_size, umode_t mode)
318{
319 debug_info_t *rc;
320
321 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
322 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
323 if (!rc)
324 goto out;
325
326 rc->mode = mode & ~S_IFMT;
327
328 /* create root directory */
329 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
330 debug_debugfs_root_entry);
331
332 /* append new element to linked list */
333 if (!debug_area_first) {
334 /* first element in list */
335 debug_area_first = rc;
336 rc->prev = NULL;
337 } else {
338 /* append element to end of list */
339 debug_area_last->next = rc;
340 rc->prev = debug_area_last;
341 }
342 debug_area_last = rc;
343 rc->next = NULL;
344
345 refcount_set(&rc->ref_count, 1);
346out:
347 return rc;
348}
349
350/*
351 * debug_info_copy
352 * - copy debug-info
353 */
354static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
355{
356 unsigned long flags;
357 debug_info_t *rc;
358 int i, j;
359
360 /* get a consistent copy of the debug areas */
361 do {
362 rc = debug_info_alloc(in->name, in->pages_per_area,
363 in->nr_areas, in->buf_size, in->level, mode);
364 spin_lock_irqsave(&in->lock, flags);
365 if (!rc)
366 goto out;
367 /* has something changed in the meantime ? */
368 if ((rc->pages_per_area == in->pages_per_area) &&
369 (rc->nr_areas == in->nr_areas)) {
370 break;
371 }
372 spin_unlock_irqrestore(&in->lock, flags);
373 debug_info_free(rc);
374 } while (1);
375
376 if (mode == NO_AREAS)
377 goto out;
378
379 for (i = 0; i < in->nr_areas; i++) {
380 for (j = 0; j < in->pages_per_area; j++)
381 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
382 }
383out:
384 spin_unlock_irqrestore(&in->lock, flags);
385 return rc;
386}
387
388/*
389 * debug_info_get
390 * - increments reference count for debug-info
391 */
392static void debug_info_get(debug_info_t *db_info)
393{
394 if (db_info)
395 refcount_inc(&db_info->ref_count);
396}
397
398/*
399 * debug_info_put:
400 * - decreases reference count for debug-info and frees it if necessary
401 */
402static void debug_info_put(debug_info_t *db_info)
403{
404 int i;
405
406 if (!db_info)
407 return;
408 if (refcount_dec_and_test(&db_info->ref_count)) {
409 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
410 if (!db_info->views[i])
411 continue;
412 debugfs_remove(db_info->debugfs_entries[i]);
413 }
414 debugfs_remove(db_info->debugfs_root_entry);
415 if (db_info == debug_area_first)
416 debug_area_first = db_info->next;
417 if (db_info == debug_area_last)
418 debug_area_last = db_info->prev;
419 if (db_info->prev)
420 db_info->prev->next = db_info->next;
421 if (db_info->next)
422 db_info->next->prev = db_info->prev;
423 debug_info_free(db_info);
424 }
425}
426
427/*
428 * debug_format_entry:
429 * - format one debug entry and return size of formated data
430 */
431static int debug_format_entry(file_private_info_t *p_info)
432{
433 debug_info_t *id_snap = p_info->debug_info_snap;
434 struct debug_view *view = p_info->view;
435 debug_entry_t *act_entry;
436 size_t len = 0;
437
438 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
439 /* print prolog */
440 if (view->prolog_proc)
441 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
442 goto out;
443 }
444 if (!id_snap->areas) /* this is true, if we have a prolog only view */
445 goto out; /* or if 'pages_per_area' is 0 */
446 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
447 [p_info->act_page] + p_info->act_entry);
448
449 if (act_entry->id.stck == 0LL)
450 goto out; /* empty entry */
451 if (view->header_proc)
452 len += view->header_proc(id_snap, view, p_info->act_area,
453 act_entry, p_info->temp_buf + len);
454 if (view->format_proc)
455 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
456 DEBUG_DATA(act_entry));
457out:
458 return len;
459}
460
461/*
462 * debug_next_entry:
463 * - goto next entry in p_info
464 */
465static inline int debug_next_entry(file_private_info_t *p_info)
466{
467 debug_info_t *id;
468
469 id = p_info->debug_info_snap;
470 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
471 p_info->act_entry = 0;
472 p_info->act_page = 0;
473 goto out;
474 }
475 if (!id->areas)
476 return 1;
477 p_info->act_entry += id->entry_size;
478 /* switch to next page, if we reached the end of the page */
479 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
480 /* next page */
481 p_info->act_entry = 0;
482 p_info->act_page += 1;
483 if ((p_info->act_page % id->pages_per_area) == 0) {
484 /* next area */
485 p_info->act_area++;
486 p_info->act_page = 0;
487 }
488 if (p_info->act_area >= id->nr_areas)
489 return 1;
490 }
491out:
492 return 0;
493}
494
495/*
496 * debug_output:
497 * - called for user read()
498 * - copies formated debug entries to the user buffer
499 */
500static ssize_t debug_output(struct file *file, /* file descriptor */
501 char __user *user_buf, /* user buffer */
502 size_t len, /* length of buffer */
503 loff_t *offset) /* offset in the file */
504{
505 size_t count = 0;
506 size_t entry_offset;
507 file_private_info_t *p_info;
508
509 p_info = (file_private_info_t *) file->private_data;
510 if (*offset != p_info->offset)
511 return -EPIPE;
512 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
513 return 0;
514 entry_offset = p_info->act_entry_offset;
515 while (count < len) {
516 int formatted_line_residue;
517 int formatted_line_size;
518 int user_buf_residue;
519 size_t copy_size;
520
521 formatted_line_size = debug_format_entry(p_info);
522 formatted_line_residue = formatted_line_size - entry_offset;
523 user_buf_residue = len-count;
524 copy_size = min(user_buf_residue, formatted_line_residue);
525 if (copy_size) {
526 if (copy_to_user(user_buf + count, p_info->temp_buf
527 + entry_offset, copy_size))
528 return -EFAULT;
529 count += copy_size;
530 entry_offset += copy_size;
531 }
532 if (copy_size == formatted_line_residue) {
533 entry_offset = 0;
534 if (debug_next_entry(p_info))
535 goto out;
536 }
537 }
538out:
539 p_info->offset = *offset + count;
540 p_info->act_entry_offset = entry_offset;
541 *offset = p_info->offset;
542 return count;
543}
544
545/*
546 * debug_input:
547 * - called for user write()
548 * - calls input function of view
549 */
550static ssize_t debug_input(struct file *file, const char __user *user_buf,
551 size_t length, loff_t *offset)
552{
553 file_private_info_t *p_info;
554 int rc = 0;
555
556 mutex_lock(&debug_mutex);
557 p_info = ((file_private_info_t *) file->private_data);
558 if (p_info->view->input_proc) {
559 rc = p_info->view->input_proc(p_info->debug_info_org,
560 p_info->view, file, user_buf,
561 length, offset);
562 } else {
563 rc = -EPERM;
564 }
565 mutex_unlock(&debug_mutex);
566 return rc; /* number of input characters */
567}
568
569/*
570 * debug_open:
571 * - called for user open()
572 * - copies formated output to private_data area of the file
573 * handle
574 */
575static int debug_open(struct inode *inode, struct file *file)
576{
577 debug_info_t *debug_info, *debug_info_snapshot;
578 file_private_info_t *p_info;
579 int i, rc = 0;
580
581 mutex_lock(&debug_mutex);
582 debug_info = file_inode(file)->i_private;
583 /* find debug view */
584 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
585 if (!debug_info->views[i])
586 continue;
587 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
588 goto found; /* found view ! */
589 }
590 /* no entry found */
591 rc = -EINVAL;
592 goto out;
593
594found:
595
596 /* Make snapshot of current debug areas to get it consistent. */
597 /* To copy all the areas is only needed, if we have a view which */
598 /* formats the debug areas. */
599
600 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
601 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
602 else
603 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
604
605 if (!debug_info_snapshot) {
606 rc = -ENOMEM;
607 goto out;
608 }
609 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
610 if (!p_info) {
611 debug_info_free(debug_info_snapshot);
612 rc = -ENOMEM;
613 goto out;
614 }
615 p_info->offset = 0;
616 p_info->debug_info_snap = debug_info_snapshot;
617 p_info->debug_info_org = debug_info;
618 p_info->view = debug_info->views[i];
619 p_info->act_area = 0;
620 p_info->act_page = 0;
621 p_info->act_entry = DEBUG_PROLOG_ENTRY;
622 p_info->act_entry_offset = 0;
623 file->private_data = p_info;
624 debug_info_get(debug_info);
625 nonseekable_open(inode, file);
626out:
627 mutex_unlock(&debug_mutex);
628 return rc;
629}
630
631/*
632 * debug_close:
633 * - called for user close()
634 * - deletes private_data area of the file handle
635 */
636static int debug_close(struct inode *inode, struct file *file)
637{
638 file_private_info_t *p_info;
639
640 p_info = (file_private_info_t *) file->private_data;
641 if (p_info->debug_info_snap)
642 debug_info_free(p_info->debug_info_snap);
643 debug_info_put(p_info->debug_info_org);
644 kfree(file->private_data);
645 return 0; /* success */
646}
647
648/*
649 * debug_register_mode:
650 * - Creates and initializes debug area for the caller
651 * The mode parameter allows to specify access rights for the s390dbf files
652 * - Returns handle for debug area
653 */
654debug_info_t *debug_register_mode(const char *name, int pages_per_area,
655 int nr_areas, int buf_size, umode_t mode,
656 uid_t uid, gid_t gid)
657{
658 debug_info_t *rc = NULL;
659
660 /* Since debugfs currently does not support uid/gid other than root, */
661 /* we do not allow gid/uid != 0 until we get support for that. */
662 if ((uid != 0) || (gid != 0))
663 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
664 BUG_ON(!initialized);
665 mutex_lock(&debug_mutex);
666
667 /* create new debug_info */
668 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
669 if (!rc)
670 goto out;
671 debug_register_view(rc, &debug_level_view);
672 debug_register_view(rc, &debug_flush_view);
673 debug_register_view(rc, &debug_pages_view);
674out:
675 if (!rc)
676 pr_err("Registering debug feature %s failed\n", name);
677 mutex_unlock(&debug_mutex);
678 return rc;
679}
680EXPORT_SYMBOL(debug_register_mode);
681
682/*
683 * debug_register:
684 * - creates and initializes debug area for the caller
685 * - returns handle for debug area
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_unregister:
697 * - give back debug area
698 */
699void debug_unregister(debug_info_t *id)
700{
701 if (!id)
702 return;
703 mutex_lock(&debug_mutex);
704 debug_info_put(id);
705 mutex_unlock(&debug_mutex);
706}
707EXPORT_SYMBOL(debug_unregister);
708
709/*
710 * debug_set_size:
711 * - set area size (number of pages) and number of areas
712 */
713static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
714{
715 debug_entry_t ***new_areas;
716 unsigned long flags;
717 int rc = 0;
718
719 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
720 return -EINVAL;
721 if (pages_per_area > 0) {
722 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
723 if (!new_areas) {
724 pr_info("Allocating memory for %i pages failed\n",
725 pages_per_area);
726 rc = -ENOMEM;
727 goto out;
728 }
729 } else {
730 new_areas = NULL;
731 }
732 spin_lock_irqsave(&id->lock, flags);
733 debug_areas_free(id);
734 id->areas = new_areas;
735 id->nr_areas = nr_areas;
736 id->pages_per_area = pages_per_area;
737 id->active_area = 0;
738 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
739 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
740 spin_unlock_irqrestore(&id->lock, flags);
741 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
742out:
743 return rc;
744}
745
746/*
747 * debug_set_level:
748 * - set actual debug level
749 */
750void debug_set_level(debug_info_t *id, int new_level)
751{
752 unsigned long flags;
753
754 if (!id)
755 return;
756 spin_lock_irqsave(&id->lock, flags);
757 if (new_level == DEBUG_OFF_LEVEL) {
758 id->level = DEBUG_OFF_LEVEL;
759 pr_info("%s: switched off\n", id->name);
760 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
761 pr_info("%s: level %i is out of range (%i - %i)\n",
762 id->name, new_level, 0, DEBUG_MAX_LEVEL);
763 } else {
764 id->level = new_level;
765 }
766 spin_unlock_irqrestore(&id->lock, flags);
767}
768EXPORT_SYMBOL(debug_set_level);
769
770/*
771 * proceed_active_entry:
772 * - set active entry to next in the ring buffer
773 */
774static inline void proceed_active_entry(debug_info_t *id)
775{
776 if ((id->active_entries[id->active_area] += id->entry_size)
777 > (PAGE_SIZE - id->entry_size)) {
778 id->active_entries[id->active_area] = 0;
779 id->active_pages[id->active_area] =
780 (id->active_pages[id->active_area] + 1) %
781 id->pages_per_area;
782 }
783}
784
785/*
786 * proceed_active_area:
787 * - set active area to next in the ring buffer
788 */
789static inline void proceed_active_area(debug_info_t *id)
790{
791 id->active_area++;
792 id->active_area = id->active_area % id->nr_areas;
793}
794
795/*
796 * get_active_entry:
797 */
798static inline debug_entry_t *get_active_entry(debug_info_t *id)
799{
800 return (debug_entry_t *) (((char *) id->areas[id->active_area]
801 [id->active_pages[id->active_area]]) +
802 id->active_entries[id->active_area]);
803}
804
805/*
806 * debug_finish_entry:
807 * - set timestamp, caller address, cpu number etc.
808 */
809
810static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
811 int level, int exception)
812{
813 active->id.stck = get_tod_clock_fast() -
814 *(unsigned long long *) &tod_clock_base[1];
815 active->id.fields.cpuid = smp_processor_id();
816 active->caller = __builtin_return_address(0);
817 active->id.fields.exception = exception;
818 active->id.fields.level = level;
819 proceed_active_entry(id);
820 if (exception)
821 proceed_active_area(id);
822}
823
824static int debug_stoppable = 1;
825static int debug_active = 1;
826
827#define CTL_S390DBF_STOPPABLE 5678
828#define CTL_S390DBF_ACTIVE 5679
829
830/*
831 * proc handler for the running debug_active sysctl
832 * always allow read, allow write only if debug_stoppable is set or
833 * if debug_active is already off
834 */
835static int s390dbf_procactive(struct ctl_table *table, int write,
836 void __user *buffer, size_t *lenp, loff_t *ppos)
837{
838 if (!write || debug_stoppable || !debug_active)
839 return proc_dointvec(table, write, buffer, lenp, ppos);
840 else
841 return 0;
842}
843
844static struct ctl_table s390dbf_table[] = {
845 {
846 .procname = "debug_stoppable",
847 .data = &debug_stoppable,
848 .maxlen = sizeof(int),
849 .mode = S_IRUGO | S_IWUSR,
850 .proc_handler = proc_dointvec,
851 },
852 {
853 .procname = "debug_active",
854 .data = &debug_active,
855 .maxlen = sizeof(int),
856 .mode = S_IRUGO | S_IWUSR,
857 .proc_handler = s390dbf_procactive,
858 },
859 { }
860};
861
862static struct ctl_table s390dbf_dir_table[] = {
863 {
864 .procname = "s390dbf",
865 .maxlen = 0,
866 .mode = S_IRUGO | S_IXUGO,
867 .child = s390dbf_table,
868 },
869 { }
870};
871
872static struct ctl_table_header *s390dbf_sysctl_header;
873
874void debug_stop_all(void)
875{
876 if (debug_stoppable)
877 debug_active = 0;
878}
879EXPORT_SYMBOL(debug_stop_all);
880
881void debug_set_critical(void)
882{
883 debug_critical = 1;
884}
885
886/*
887 * debug_event_common:
888 * - write debug entry with given size
889 */
890debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
891 int len)
892{
893 debug_entry_t *active;
894 unsigned long flags;
895
896 if (!debug_active || !id->areas)
897 return NULL;
898 if (debug_critical) {
899 if (!spin_trylock_irqsave(&id->lock, flags))
900 return NULL;
901 } else {
902 spin_lock_irqsave(&id->lock, flags);
903 }
904 do {
905 active = get_active_entry(id);
906 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
907 if (len < id->buf_size)
908 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
909 debug_finish_entry(id, active, level, 0);
910 len -= id->buf_size;
911 buf += id->buf_size;
912 } while (len > 0);
913
914 spin_unlock_irqrestore(&id->lock, flags);
915 return active;
916}
917EXPORT_SYMBOL(debug_event_common);
918
919/*
920 * debug_exception_common:
921 * - write debug entry with given size and switch to next debug area
922 */
923debug_entry_t *debug_exception_common(debug_info_t *id, int level,
924 const void *buf, int len)
925{
926 debug_entry_t *active;
927 unsigned long flags;
928
929 if (!debug_active || !id->areas)
930 return NULL;
931 if (debug_critical) {
932 if (!spin_trylock_irqsave(&id->lock, flags))
933 return NULL;
934 } else {
935 spin_lock_irqsave(&id->lock, flags);
936 }
937 do {
938 active = get_active_entry(id);
939 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
940 if (len < id->buf_size)
941 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
942 debug_finish_entry(id, active, level, len <= id->buf_size);
943 len -= id->buf_size;
944 buf += id->buf_size;
945 } while (len > 0);
946
947 spin_unlock_irqrestore(&id->lock, flags);
948 return active;
949}
950EXPORT_SYMBOL(debug_exception_common);
951
952/*
953 * counts arguments in format string for sprintf view
954 */
955static inline int debug_count_numargs(char *string)
956{
957 int numargs = 0;
958
959 while (*string) {
960 if (*string++ == '%')
961 numargs++;
962 }
963 return numargs;
964}
965
966/*
967 * debug_sprintf_event:
968 */
969debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
970{
971 debug_sprintf_entry_t *curr_event;
972 debug_entry_t *active;
973 unsigned long flags;
974 int numargs, idx;
975 va_list ap;
976
977 if (!debug_active || !id->areas)
978 return NULL;
979 numargs = debug_count_numargs(string);
980
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 }
987 active = get_active_entry(id);
988 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
989 va_start(ap, string);
990 curr_event->string = string;
991 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
992 curr_event->args[idx] = va_arg(ap, long);
993 va_end(ap);
994 debug_finish_entry(id, active, level, 0);
995 spin_unlock_irqrestore(&id->lock, flags);
996
997 return active;
998}
999EXPORT_SYMBOL(__debug_sprintf_event);
1000
1001/*
1002 * debug_sprintf_exception:
1003 */
1004debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1005{
1006 debug_sprintf_entry_t *curr_event;
1007 debug_entry_t *active;
1008 unsigned long flags;
1009 int numargs, idx;
1010 va_list ap;
1011
1012 if (!debug_active || !id->areas)
1013 return NULL;
1014
1015 numargs = debug_count_numargs(string);
1016
1017 if (debug_critical) {
1018 if (!spin_trylock_irqsave(&id->lock, flags))
1019 return NULL;
1020 } else {
1021 spin_lock_irqsave(&id->lock, flags);
1022 }
1023 active = get_active_entry(id);
1024 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1025 va_start(ap, string);
1026 curr_event->string = string;
1027 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1028 curr_event->args[idx] = va_arg(ap, long);
1029 va_end(ap);
1030 debug_finish_entry(id, active, level, 1);
1031 spin_unlock_irqrestore(&id->lock, flags);
1032
1033 return active;
1034}
1035EXPORT_SYMBOL(__debug_sprintf_exception);
1036
1037/*
1038 * debug_register_view:
1039 */
1040int debug_register_view(debug_info_t *id, struct debug_view *view)
1041{
1042 unsigned long flags;
1043 struct dentry *pde;
1044 umode_t mode;
1045 int rc = 0;
1046 int i;
1047
1048 if (!id)
1049 goto out;
1050 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1051 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1052 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1053 if (!view->input_proc)
1054 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1055 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1056 id, &debug_file_ops);
1057 if (!pde) {
1058 pr_err("Registering view %s/%s failed due to out of "
1059 "memory\n", id->name, view->name);
1060 rc = -1;
1061 goto out;
1062 }
1063 spin_lock_irqsave(&id->lock, flags);
1064 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1065 if (!id->views[i])
1066 break;
1067 }
1068 if (i == DEBUG_MAX_VIEWS) {
1069 pr_err("Registering view %s/%s would exceed the maximum "
1070 "number of views %i\n", id->name, view->name, i);
1071 rc = -1;
1072 } else {
1073 id->views[i] = view;
1074 id->debugfs_entries[i] = pde;
1075 }
1076 spin_unlock_irqrestore(&id->lock, flags);
1077 if (rc)
1078 debugfs_remove(pde);
1079out:
1080 return rc;
1081}
1082EXPORT_SYMBOL(debug_register_view);
1083
1084/*
1085 * debug_unregister_view:
1086 */
1087int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1088{
1089 struct dentry *dentry = NULL;
1090 unsigned long flags;
1091 int i, rc = 0;
1092
1093 if (!id)
1094 goto out;
1095 spin_lock_irqsave(&id->lock, flags);
1096 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1097 if (id->views[i] == view)
1098 break;
1099 }
1100 if (i == DEBUG_MAX_VIEWS) {
1101 rc = -1;
1102 } else {
1103 dentry = id->debugfs_entries[i];
1104 id->views[i] = NULL;
1105 id->debugfs_entries[i] = NULL;
1106 }
1107 spin_unlock_irqrestore(&id->lock, flags);
1108 debugfs_remove(dentry);
1109out:
1110 return rc;
1111}
1112EXPORT_SYMBOL(debug_unregister_view);
1113
1114static inline char *debug_get_user_string(const char __user *user_buf,
1115 size_t user_len)
1116{
1117 char *buffer;
1118
1119 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1120 if (!buffer)
1121 return ERR_PTR(-ENOMEM);
1122 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1123 kfree(buffer);
1124 return ERR_PTR(-EFAULT);
1125 }
1126 /* got the string, now strip linefeed. */
1127 if (buffer[user_len - 1] == '\n')
1128 buffer[user_len - 1] = 0;
1129 else
1130 buffer[user_len] = 0;
1131 return buffer;
1132}
1133
1134static inline int debug_get_uint(char *buf)
1135{
1136 int rc;
1137
1138 buf = skip_spaces(buf);
1139 rc = simple_strtoul(buf, &buf, 10);
1140 if (*buf)
1141 rc = -EINVAL;
1142 return rc;
1143}
1144
1145/*
1146 * functions for debug-views
1147 ***********************************
1148*/
1149
1150/*
1151 * prints out actual debug level
1152 */
1153
1154static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1155 char *out_buf)
1156{
1157 return sprintf(out_buf, "%i\n", id->pages_per_area);
1158}
1159
1160/*
1161 * reads new size (number of pages per debug area)
1162 */
1163
1164static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1165 struct file *file, const char __user *user_buf,
1166 size_t user_len, loff_t *offset)
1167{
1168 int rc, new_pages;
1169 char *str;
1170
1171 if (user_len > 0x10000)
1172 user_len = 0x10000;
1173 if (*offset != 0) {
1174 rc = -EPIPE;
1175 goto out;
1176 }
1177 str = debug_get_user_string(user_buf, user_len);
1178 if (IS_ERR(str)) {
1179 rc = PTR_ERR(str);
1180 goto out;
1181 }
1182 new_pages = debug_get_uint(str);
1183 if (new_pages < 0) {
1184 rc = -EINVAL;
1185 goto free_str;
1186 }
1187 rc = debug_set_size(id, id->nr_areas, new_pages);
1188 if (rc != 0) {
1189 rc = -EINVAL;
1190 goto free_str;
1191 }
1192 rc = user_len;
1193free_str:
1194 kfree(str);
1195out:
1196 *offset += user_len;
1197 return rc; /* number of input characters */
1198}
1199
1200/*
1201 * prints out actual debug level
1202 */
1203static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1204 char *out_buf)
1205{
1206 int rc = 0;
1207
1208 if (id->level == DEBUG_OFF_LEVEL)
1209 rc = sprintf(out_buf, "-\n");
1210 else
1211 rc = sprintf(out_buf, "%i\n", id->level);
1212 return rc;
1213}
1214
1215/*
1216 * reads new debug level
1217 */
1218static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1219 struct file *file, const char __user *user_buf,
1220 size_t user_len, loff_t *offset)
1221{
1222 int rc, new_level;
1223 char *str;
1224
1225 if (user_len > 0x10000)
1226 user_len = 0x10000;
1227 if (*offset != 0) {
1228 rc = -EPIPE;
1229 goto out;
1230 }
1231 str = debug_get_user_string(user_buf, user_len);
1232 if (IS_ERR(str)) {
1233 rc = PTR_ERR(str);
1234 goto out;
1235 }
1236 if (str[0] == '-') {
1237 debug_set_level(id, DEBUG_OFF_LEVEL);
1238 rc = user_len;
1239 goto free_str;
1240 } else {
1241 new_level = debug_get_uint(str);
1242 }
1243 if (new_level < 0) {
1244 pr_warn("%s is not a valid level for a debug feature\n", str);
1245 rc = -EINVAL;
1246 } else {
1247 debug_set_level(id, new_level);
1248 rc = user_len;
1249 }
1250free_str:
1251 kfree(str);
1252out:
1253 *offset += user_len;
1254 return rc; /* number of input characters */
1255}
1256
1257/*
1258 * flushes debug areas
1259 */
1260static void debug_flush(debug_info_t *id, int area)
1261{
1262 unsigned long flags;
1263 int i, j;
1264
1265 if (!id || !id->areas)
1266 return;
1267 spin_lock_irqsave(&id->lock, flags);
1268 if (area == DEBUG_FLUSH_ALL) {
1269 id->active_area = 0;
1270 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1271 for (i = 0; i < id->nr_areas; i++) {
1272 id->active_pages[i] = 0;
1273 for (j = 0; j < id->pages_per_area; j++)
1274 memset(id->areas[i][j], 0, PAGE_SIZE);
1275 }
1276 } else if (area >= 0 && area < id->nr_areas) {
1277 id->active_entries[area] = 0;
1278 id->active_pages[area] = 0;
1279 for (i = 0; i < id->pages_per_area; i++)
1280 memset(id->areas[area][i], 0, PAGE_SIZE);
1281 }
1282 spin_unlock_irqrestore(&id->lock, flags);
1283}
1284
1285/*
1286 * view function: flushes debug areas
1287 */
1288static int debug_input_flush_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 input_buf[1];
1293 int rc = user_len;
1294
1295 if (user_len > 0x10000)
1296 user_len = 0x10000;
1297 if (*offset != 0) {
1298 rc = -EPIPE;
1299 goto out;
1300 }
1301 if (copy_from_user(input_buf, user_buf, 1)) {
1302 rc = -EFAULT;
1303 goto out;
1304 }
1305 if (input_buf[0] == '-') {
1306 debug_flush(id, DEBUG_FLUSH_ALL);
1307 goto out;
1308 }
1309 if (isdigit(input_buf[0])) {
1310 int area = ((int) input_buf[0] - (int) '0');
1311
1312 debug_flush(id, area);
1313 goto out;
1314 }
1315
1316 pr_info("Flushing debug data failed because %c is not a valid "
1317 "area\n", input_buf[0]);
1318
1319out:
1320 *offset += user_len;
1321 return rc; /* number of input characters */
1322}
1323
1324/*
1325 * prints debug header in raw format
1326 */
1327static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1328 int area, debug_entry_t *entry, char *out_buf)
1329{
1330 int rc;
1331
1332 rc = sizeof(debug_entry_t);
1333 memcpy(out_buf, entry, sizeof(debug_entry_t));
1334 return rc;
1335}
1336
1337/*
1338 * prints debug data in raw format
1339 */
1340static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1341 char *out_buf, const char *in_buf)
1342{
1343 int rc;
1344
1345 rc = id->buf_size;
1346 memcpy(out_buf, in_buf, id->buf_size);
1347 return rc;
1348}
1349
1350/*
1351 * prints debug data in hex/ascii format
1352 */
1353static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1354 char *out_buf, const char *in_buf)
1355{
1356 int i, rc = 0;
1357
1358 for (i = 0; i < id->buf_size; i++)
1359 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1360 rc += sprintf(out_buf + rc, "| ");
1361 for (i = 0; i < id->buf_size; i++) {
1362 unsigned char c = in_buf[i];
1363
1364 if (isascii(c) && isprint(c))
1365 rc += sprintf(out_buf + rc, "%c", c);
1366 else
1367 rc += sprintf(out_buf + rc, ".");
1368 }
1369 rc += sprintf(out_buf + rc, "\n");
1370 return rc;
1371}
1372
1373/*
1374 * prints header for debug entry
1375 */
1376int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1377 int area, debug_entry_t *entry, char *out_buf)
1378{
1379 unsigned long base, sec, usec;
1380 unsigned long caller;
1381 unsigned int level;
1382 char *except_str;
1383 int rc = 0;
1384
1385 level = entry->id.fields.level;
1386 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1387 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1388 usec = do_div(sec, USEC_PER_SEC);
1389
1390 if (entry->id.fields.exception)
1391 except_str = "*";
1392 else
1393 except_str = "-";
1394 caller = (unsigned long) entry->caller;
1395 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1396 area, sec, usec, level, except_str,
1397 entry->id.fields.cpuid, (void *)caller);
1398 return rc;
1399}
1400EXPORT_SYMBOL(debug_dflt_header_fn);
1401
1402/*
1403 * prints debug data sprintf-formated:
1404 * debug_sprinf_event/exception calls must be used together with this view
1405 */
1406
1407#define DEBUG_SPRINTF_MAX_ARGS 10
1408
1409static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1410 char *out_buf, debug_sprintf_entry_t *curr_event)
1411{
1412 int num_longs, num_used_args = 0, i, rc = 0;
1413 int index[DEBUG_SPRINTF_MAX_ARGS];
1414
1415 /* count of longs fit into one entry */
1416 num_longs = id->buf_size / sizeof(long);
1417
1418 if (num_longs < 1)
1419 goto out; /* bufsize of entry too small */
1420 if (num_longs == 1) {
1421 /* no args, we use only the string */
1422 strcpy(out_buf, curr_event->string);
1423 rc = strlen(curr_event->string);
1424 goto out;
1425 }
1426
1427 /* number of arguments used for sprintf (without the format string) */
1428 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1429
1430 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1431
1432 for (i = 0; i < num_used_args; i++)
1433 index[i] = i;
1434
1435 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1436 curr_event->args[index[1]], curr_event->args[index[2]],
1437 curr_event->args[index[3]], curr_event->args[index[4]],
1438 curr_event->args[index[5]], curr_event->args[index[6]],
1439 curr_event->args[index[7]], curr_event->args[index[8]],
1440 curr_event->args[index[9]]);
1441out:
1442 return rc;
1443}
1444
1445/*
1446 * debug_init:
1447 * - is called exactly once to initialize the debug feature
1448 */
1449static int __init debug_init(void)
1450{
1451 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1452 mutex_lock(&debug_mutex);
1453 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1454 initialized = 1;
1455 mutex_unlock(&debug_mutex);
1456 return 0;
1457}
1458postcore_initcall(debug_init);
1/*
2 * arch/s390/kernel/debug.c
3 * S/390 debug facility
4 *
5 * Copyright (C) 1999, 2000 IBM Deutschland Entwicklung GmbH,
6 * IBM Corporation
7 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
8 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
9 *
10 * Bugreports to: <Linux390@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "s390dbf"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/ctype.h>
21#include <linux/string.h>
22#include <linux/sysctl.h>
23#include <asm/uaccess.h>
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/debugfs.h>
28
29#include <asm/debug.h>
30
31#define DEBUG_PROLOG_ENTRY -1
32
33#define ALL_AREAS 0 /* copy all debug areas */
34#define NO_AREAS 1 /* copy no debug areas */
35
36/* typedefs */
37
38typedef struct file_private_info {
39 loff_t offset; /* offset of last read in file */
40 int act_area; /* number of last formated area */
41 int act_page; /* act page in given area */
42 int act_entry; /* last formated entry (offset */
43 /* relative to beginning of last */
44 /* formated page) */
45 size_t act_entry_offset; /* up to this offset we copied */
46 /* in last read the last formated */
47 /* entry to userland */
48 char temp_buf[2048]; /* buffer for output */
49 debug_info_t *debug_info_org; /* original debug information */
50 debug_info_t *debug_info_snap; /* snapshot of debug information */
51 struct debug_view *view; /* used view of debug info */
52} file_private_info_t;
53
54typedef struct
55{
56 char *string;
57 /*
58 * This assumes that all args are converted into longs
59 * on L/390 this is the case for all types of parameter
60 * except of floats, and long long (32 bit)
61 *
62 */
63 long args[0];
64} debug_sprintf_entry_t;
65
66
67/* internal function prototyes */
68
69static int debug_init(void);
70static ssize_t debug_output(struct file *file, char __user *user_buf,
71 size_t user_len, loff_t * offset);
72static ssize_t debug_input(struct file *file, const char __user *user_buf,
73 size_t user_len, loff_t * offset);
74static int debug_open(struct inode *inode, struct file *file);
75static int debug_close(struct inode *inode, struct file *file);
76static debug_info_t *debug_info_create(const char *name, int pages_per_area,
77 int nr_areas, int buf_size, mode_t mode);
78static void debug_info_get(debug_info_t *);
79static void debug_info_put(debug_info_t *);
80static int debug_prolog_level_fn(debug_info_t * id,
81 struct debug_view *view, char *out_buf);
82static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
83 struct file *file, const char __user *user_buf,
84 size_t user_buf_size, loff_t * offset);
85static int debug_prolog_pages_fn(debug_info_t * id,
86 struct debug_view *view, char *out_buf);
87static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
88 struct file *file, const char __user *user_buf,
89 size_t user_buf_size, loff_t * offset);
90static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
91 struct file *file, const char __user *user_buf,
92 size_t user_buf_size, loff_t * offset);
93static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
94 char *out_buf, const char *in_buf);
95static int debug_raw_format_fn(debug_info_t * id,
96 struct debug_view *view, char *out_buf,
97 const char *in_buf);
98static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
99 int area, debug_entry_t * entry, char *out_buf);
100
101static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
102 char *out_buf, debug_sprintf_entry_t *curr_event);
103
104/* globals */
105
106struct debug_view debug_raw_view = {
107 "raw",
108 NULL,
109 &debug_raw_header_fn,
110 &debug_raw_format_fn,
111 NULL,
112 NULL
113};
114
115struct debug_view debug_hex_ascii_view = {
116 "hex_ascii",
117 NULL,
118 &debug_dflt_header_fn,
119 &debug_hex_ascii_format_fn,
120 NULL,
121 NULL
122};
123
124static struct debug_view debug_level_view = {
125 "level",
126 &debug_prolog_level_fn,
127 NULL,
128 NULL,
129 &debug_input_level_fn,
130 NULL
131};
132
133static struct debug_view debug_pages_view = {
134 "pages",
135 &debug_prolog_pages_fn,
136 NULL,
137 NULL,
138 &debug_input_pages_fn,
139 NULL
140};
141
142static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149};
150
151struct debug_view debug_sprintf_view = {
152 "sprintf",
153 NULL,
154 &debug_dflt_header_fn,
155 (debug_format_proc_t*)&debug_sprintf_format_fn,
156 NULL,
157 NULL
158};
159
160/* used by dump analysis tools to determine version of debug feature */
161static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
162
163/* static globals */
164
165static debug_info_t *debug_area_first = NULL;
166static debug_info_t *debug_area_last = NULL;
167static DEFINE_MUTEX(debug_mutex);
168
169static int initialized;
170
171static const struct file_operations debug_file_ops = {
172 .owner = THIS_MODULE,
173 .read = debug_output,
174 .write = debug_input,
175 .open = debug_open,
176 .release = debug_close,
177 .llseek = no_llseek,
178};
179
180static struct dentry *debug_debugfs_root_entry;
181
182/* functions */
183
184/*
185 * debug_areas_alloc
186 * - Debug areas are implemented as a threedimensonal array:
187 * areas[areanumber][pagenumber][pageoffset]
188 */
189
190static debug_entry_t***
191debug_areas_alloc(int pages_per_area, int nr_areas)
192{
193 debug_entry_t*** areas;
194 int i,j;
195
196 areas = kmalloc(nr_areas *
197 sizeof(debug_entry_t**),
198 GFP_KERNEL);
199 if (!areas)
200 goto fail_malloc_areas;
201 for (i = 0; i < nr_areas; i++) {
202 areas[i] = kmalloc(pages_per_area *
203 sizeof(debug_entry_t*),GFP_KERNEL);
204 if (!areas[i]) {
205 goto fail_malloc_areas2;
206 }
207 for(j = 0; j < pages_per_area; j++) {
208 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
209 if(!areas[i][j]) {
210 for(j--; j >=0 ; j--) {
211 kfree(areas[i][j]);
212 }
213 kfree(areas[i]);
214 goto fail_malloc_areas2;
215 }
216 }
217 }
218 return areas;
219
220fail_malloc_areas2:
221 for(i--; i >= 0; i--){
222 for(j=0; j < pages_per_area;j++){
223 kfree(areas[i][j]);
224 }
225 kfree(areas[i]);
226 }
227 kfree(areas);
228fail_malloc_areas:
229 return NULL;
230
231}
232
233
234/*
235 * debug_info_alloc
236 * - alloc new debug-info
237 */
238
239static debug_info_t*
240debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
241 int buf_size, int level, int mode)
242{
243 debug_info_t* rc;
244
245 /* alloc everything */
246
247 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
248 if(!rc)
249 goto fail_malloc_rc;
250 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
251 if(!rc->active_entries)
252 goto fail_malloc_active_entries;
253 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254 if(!rc->active_pages)
255 goto fail_malloc_active_pages;
256 if((mode == ALL_AREAS) && (pages_per_area != 0)){
257 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
258 if(!rc->areas)
259 goto fail_malloc_areas;
260 } else {
261 rc->areas = NULL;
262 }
263
264 /* initialize members */
265
266 spin_lock_init(&rc->lock);
267 rc->pages_per_area = pages_per_area;
268 rc->nr_areas = nr_areas;
269 rc->active_area = 0;
270 rc->level = level;
271 rc->buf_size = buf_size;
272 rc->entry_size = sizeof(debug_entry_t) + buf_size;
273 strlcpy(rc->name, name, sizeof(rc->name));
274 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
275 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
276 sizeof(struct dentry*));
277 atomic_set(&(rc->ref_count), 0);
278
279 return rc;
280
281fail_malloc_areas:
282 kfree(rc->active_pages);
283fail_malloc_active_pages:
284 kfree(rc->active_entries);
285fail_malloc_active_entries:
286 kfree(rc);
287fail_malloc_rc:
288 return NULL;
289}
290
291/*
292 * debug_areas_free
293 * - free all debug areas
294 */
295
296static void
297debug_areas_free(debug_info_t* db_info)
298{
299 int i,j;
300
301 if(!db_info->areas)
302 return;
303 for (i = 0; i < db_info->nr_areas; i++) {
304 for(j = 0; j < db_info->pages_per_area; j++) {
305 kfree(db_info->areas[i][j]);
306 }
307 kfree(db_info->areas[i]);
308 }
309 kfree(db_info->areas);
310 db_info->areas = NULL;
311}
312
313/*
314 * debug_info_free
315 * - free memory debug-info
316 */
317
318static void
319debug_info_free(debug_info_t* db_info){
320 debug_areas_free(db_info);
321 kfree(db_info->active_entries);
322 kfree(db_info->active_pages);
323 kfree(db_info);
324}
325
326/*
327 * debug_info_create
328 * - create new debug-info
329 */
330
331static debug_info_t*
332debug_info_create(const char *name, int pages_per_area, int nr_areas,
333 int buf_size, mode_t mode)
334{
335 debug_info_t* rc;
336
337 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
338 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
339 if(!rc)
340 goto out;
341
342 rc->mode = mode & ~S_IFMT;
343
344 /* create root directory */
345 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
346 debug_debugfs_root_entry);
347
348 /* append new element to linked list */
349 if (!debug_area_first) {
350 /* first element in list */
351 debug_area_first = rc;
352 rc->prev = NULL;
353 } else {
354 /* append element to end of list */
355 debug_area_last->next = rc;
356 rc->prev = debug_area_last;
357 }
358 debug_area_last = rc;
359 rc->next = NULL;
360
361 debug_info_get(rc);
362out:
363 return rc;
364}
365
366/*
367 * debug_info_copy
368 * - copy debug-info
369 */
370
371static debug_info_t*
372debug_info_copy(debug_info_t* in, int mode)
373{
374 int i,j;
375 debug_info_t* rc;
376 unsigned long flags;
377
378 /* get a consistent copy of the debug areas */
379 do {
380 rc = debug_info_alloc(in->name, in->pages_per_area,
381 in->nr_areas, in->buf_size, in->level, mode);
382 spin_lock_irqsave(&in->lock, flags);
383 if(!rc)
384 goto out;
385 /* has something changed in the meantime ? */
386 if((rc->pages_per_area == in->pages_per_area) &&
387 (rc->nr_areas == in->nr_areas)) {
388 break;
389 }
390 spin_unlock_irqrestore(&in->lock, flags);
391 debug_info_free(rc);
392 } while (1);
393
394 if (mode == NO_AREAS)
395 goto out;
396
397 for(i = 0; i < in->nr_areas; i++){
398 for(j = 0; j < in->pages_per_area; j++) {
399 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
400 }
401 }
402out:
403 spin_unlock_irqrestore(&in->lock, flags);
404 return rc;
405}
406
407/*
408 * debug_info_get
409 * - increments reference count for debug-info
410 */
411
412static void
413debug_info_get(debug_info_t * db_info)
414{
415 if (db_info)
416 atomic_inc(&db_info->ref_count);
417}
418
419/*
420 * debug_info_put:
421 * - decreases reference count for debug-info and frees it if necessary
422 */
423
424static void
425debug_info_put(debug_info_t *db_info)
426{
427 int i;
428
429 if (!db_info)
430 return;
431 if (atomic_dec_and_test(&db_info->ref_count)) {
432 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
433 if (!db_info->views[i])
434 continue;
435 debugfs_remove(db_info->debugfs_entries[i]);
436 }
437 debugfs_remove(db_info->debugfs_root_entry);
438 if(db_info == debug_area_first)
439 debug_area_first = db_info->next;
440 if(db_info == debug_area_last)
441 debug_area_last = db_info->prev;
442 if(db_info->prev) db_info->prev->next = db_info->next;
443 if(db_info->next) db_info->next->prev = db_info->prev;
444 debug_info_free(db_info);
445 }
446}
447
448/*
449 * debug_format_entry:
450 * - format one debug entry and return size of formated data
451 */
452
453static int
454debug_format_entry(file_private_info_t *p_info)
455{
456 debug_info_t *id_snap = p_info->debug_info_snap;
457 struct debug_view *view = p_info->view;
458 debug_entry_t *act_entry;
459 size_t len = 0;
460 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
461 /* print prolog */
462 if (view->prolog_proc)
463 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
464 goto out;
465 }
466 if (!id_snap->areas) /* this is true, if we have a prolog only view */
467 goto out; /* or if 'pages_per_area' is 0 */
468 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
469 [p_info->act_page] + p_info->act_entry);
470
471 if (act_entry->id.stck == 0LL)
472 goto out; /* empty entry */
473 if (view->header_proc)
474 len += view->header_proc(id_snap, view, p_info->act_area,
475 act_entry, p_info->temp_buf + len);
476 if (view->format_proc)
477 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
478 DEBUG_DATA(act_entry));
479out:
480 return len;
481}
482
483/*
484 * debug_next_entry:
485 * - goto next entry in p_info
486 */
487
488static inline int
489debug_next_entry(file_private_info_t *p_info)
490{
491 debug_info_t *id;
492
493 id = p_info->debug_info_snap;
494 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
495 p_info->act_entry = 0;
496 p_info->act_page = 0;
497 goto out;
498 }
499 if(!id->areas)
500 return 1;
501 p_info->act_entry += id->entry_size;
502 /* switch to next page, if we reached the end of the page */
503 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
504 /* next page */
505 p_info->act_entry = 0;
506 p_info->act_page += 1;
507 if((p_info->act_page % id->pages_per_area) == 0) {
508 /* next area */
509 p_info->act_area++;
510 p_info->act_page=0;
511 }
512 if(p_info->act_area >= id->nr_areas)
513 return 1;
514 }
515out:
516 return 0;
517}
518
519/*
520 * debug_output:
521 * - called for user read()
522 * - copies formated debug entries to the user buffer
523 */
524
525static ssize_t
526debug_output(struct file *file, /* file descriptor */
527 char __user *user_buf, /* user buffer */
528 size_t len, /* length of buffer */
529 loff_t *offset) /* offset in the file */
530{
531 size_t count = 0;
532 size_t entry_offset;
533 file_private_info_t *p_info;
534
535 p_info = ((file_private_info_t *) file->private_data);
536 if (*offset != p_info->offset)
537 return -EPIPE;
538 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
539 return 0;
540 entry_offset = p_info->act_entry_offset;
541 while(count < len){
542 int formatted_line_size;
543 int formatted_line_residue;
544 int user_buf_residue;
545 size_t copy_size;
546
547 formatted_line_size = debug_format_entry(p_info);
548 formatted_line_residue = formatted_line_size - entry_offset;
549 user_buf_residue = len-count;
550 copy_size = min(user_buf_residue, formatted_line_residue);
551 if(copy_size){
552 if (copy_to_user(user_buf + count, p_info->temp_buf
553 + entry_offset, copy_size))
554 return -EFAULT;
555 count += copy_size;
556 entry_offset += copy_size;
557 }
558 if(copy_size == formatted_line_residue){
559 entry_offset = 0;
560 if(debug_next_entry(p_info))
561 goto out;
562 }
563 }
564out:
565 p_info->offset = *offset + count;
566 p_info->act_entry_offset = entry_offset;
567 *offset = p_info->offset;
568 return count;
569}
570
571/*
572 * debug_input:
573 * - called for user write()
574 * - calls input function of view
575 */
576
577static ssize_t
578debug_input(struct file *file, const char __user *user_buf, size_t length,
579 loff_t *offset)
580{
581 int rc = 0;
582 file_private_info_t *p_info;
583
584 mutex_lock(&debug_mutex);
585 p_info = ((file_private_info_t *) file->private_data);
586 if (p_info->view->input_proc)
587 rc = p_info->view->input_proc(p_info->debug_info_org,
588 p_info->view, file, user_buf,
589 length, offset);
590 else
591 rc = -EPERM;
592 mutex_unlock(&debug_mutex);
593 return rc; /* number of input characters */
594}
595
596/*
597 * debug_open:
598 * - called for user open()
599 * - copies formated output to private_data area of the file
600 * handle
601 */
602
603static int
604debug_open(struct inode *inode, struct file *file)
605{
606 int i, rc = 0;
607 file_private_info_t *p_info;
608 debug_info_t *debug_info, *debug_info_snapshot;
609
610 mutex_lock(&debug_mutex);
611 debug_info = file->f_path.dentry->d_inode->i_private;
612 /* find debug view */
613 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
614 if (!debug_info->views[i])
615 continue;
616 else if (debug_info->debugfs_entries[i] ==
617 file->f_path.dentry) {
618 goto found; /* found view ! */
619 }
620 }
621 /* no entry found */
622 rc = -EINVAL;
623 goto out;
624
625found:
626
627 /* Make snapshot of current debug areas to get it consistent. */
628 /* To copy all the areas is only needed, if we have a view which */
629 /* formats the debug areas. */
630
631 if(!debug_info->views[i]->format_proc &&
632 !debug_info->views[i]->header_proc){
633 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
634 } else {
635 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
636 }
637
638 if(!debug_info_snapshot){
639 rc = -ENOMEM;
640 goto out;
641 }
642 p_info = kmalloc(sizeof(file_private_info_t),
643 GFP_KERNEL);
644 if(!p_info){
645 debug_info_free(debug_info_snapshot);
646 rc = -ENOMEM;
647 goto out;
648 }
649 p_info->offset = 0;
650 p_info->debug_info_snap = debug_info_snapshot;
651 p_info->debug_info_org = debug_info;
652 p_info->view = debug_info->views[i];
653 p_info->act_area = 0;
654 p_info->act_page = 0;
655 p_info->act_entry = DEBUG_PROLOG_ENTRY;
656 p_info->act_entry_offset = 0;
657 file->private_data = p_info;
658 debug_info_get(debug_info);
659 nonseekable_open(inode, file);
660out:
661 mutex_unlock(&debug_mutex);
662 return rc;
663}
664
665/*
666 * debug_close:
667 * - called for user close()
668 * - deletes private_data area of the file handle
669 */
670
671static int
672debug_close(struct inode *inode, struct file *file)
673{
674 file_private_info_t *p_info;
675 p_info = (file_private_info_t *) file->private_data;
676 if(p_info->debug_info_snap)
677 debug_info_free(p_info->debug_info_snap);
678 debug_info_put(p_info->debug_info_org);
679 kfree(file->private_data);
680 return 0; /* success */
681}
682
683/*
684 * debug_register_mode:
685 * - Creates and initializes debug area for the caller
686 * The mode parameter allows to specify access rights for the s390dbf files
687 * - Returns handle for debug area
688 */
689
690debug_info_t *debug_register_mode(const char *name, int pages_per_area,
691 int nr_areas, int buf_size, mode_t mode,
692 uid_t uid, gid_t gid)
693{
694 debug_info_t *rc = NULL;
695
696 /* Since debugfs currently does not support uid/gid other than root, */
697 /* we do not allow gid/uid != 0 until we get support for that. */
698 if ((uid != 0) || (gid != 0))
699 pr_warning("Root becomes the owner of all s390dbf files "
700 "in sysfs\n");
701 BUG_ON(!initialized);
702 mutex_lock(&debug_mutex);
703
704 /* create new debug_info */
705
706 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
707 if(!rc)
708 goto out;
709 debug_register_view(rc, &debug_level_view);
710 debug_register_view(rc, &debug_flush_view);
711 debug_register_view(rc, &debug_pages_view);
712out:
713 if (!rc){
714 pr_err("Registering debug feature %s failed\n", name);
715 }
716 mutex_unlock(&debug_mutex);
717 return rc;
718}
719EXPORT_SYMBOL(debug_register_mode);
720
721/*
722 * debug_register:
723 * - creates and initializes debug area for the caller
724 * - returns handle for debug area
725 */
726
727debug_info_t *debug_register(const char *name, int pages_per_area,
728 int nr_areas, int buf_size)
729{
730 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
731 S_IRUSR | S_IWUSR, 0, 0);
732}
733
734/*
735 * debug_unregister:
736 * - give back debug area
737 */
738
739void
740debug_unregister(debug_info_t * id)
741{
742 if (!id)
743 goto out;
744 mutex_lock(&debug_mutex);
745 debug_info_put(id);
746 mutex_unlock(&debug_mutex);
747
748out:
749 return;
750}
751
752/*
753 * debug_set_size:
754 * - set area size (number of pages) and number of areas
755 */
756static int
757debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
758{
759 unsigned long flags;
760 debug_entry_t *** new_areas;
761 int rc=0;
762
763 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
764 return -EINVAL;
765 if(pages_per_area > 0){
766 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
767 if(!new_areas) {
768 pr_info("Allocating memory for %i pages failed\n",
769 pages_per_area);
770 rc = -ENOMEM;
771 goto out;
772 }
773 } else {
774 new_areas = NULL;
775 }
776 spin_lock_irqsave(&id->lock,flags);
777 debug_areas_free(id);
778 id->areas = new_areas;
779 id->nr_areas = nr_areas;
780 id->pages_per_area = pages_per_area;
781 id->active_area = 0;
782 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
783 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
784 spin_unlock_irqrestore(&id->lock,flags);
785 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
786out:
787 return rc;
788}
789
790/*
791 * debug_set_level:
792 * - set actual debug level
793 */
794
795void
796debug_set_level(debug_info_t* id, int new_level)
797{
798 unsigned long flags;
799 if(!id)
800 return;
801 spin_lock_irqsave(&id->lock,flags);
802 if(new_level == DEBUG_OFF_LEVEL){
803 id->level = DEBUG_OFF_LEVEL;
804 pr_info("%s: switched off\n",id->name);
805 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
806 pr_info("%s: level %i is out of range (%i - %i)\n",
807 id->name, new_level, 0, DEBUG_MAX_LEVEL);
808 } else {
809 id->level = new_level;
810 }
811 spin_unlock_irqrestore(&id->lock,flags);
812}
813
814
815/*
816 * proceed_active_entry:
817 * - set active entry to next in the ring buffer
818 */
819
820static inline void
821proceed_active_entry(debug_info_t * id)
822{
823 if ((id->active_entries[id->active_area] += id->entry_size)
824 > (PAGE_SIZE - id->entry_size)){
825 id->active_entries[id->active_area] = 0;
826 id->active_pages[id->active_area] =
827 (id->active_pages[id->active_area] + 1) %
828 id->pages_per_area;
829 }
830}
831
832/*
833 * proceed_active_area:
834 * - set active area to next in the ring buffer
835 */
836
837static inline void
838proceed_active_area(debug_info_t * id)
839{
840 id->active_area++;
841 id->active_area = id->active_area % id->nr_areas;
842}
843
844/*
845 * get_active_entry:
846 */
847
848static inline debug_entry_t*
849get_active_entry(debug_info_t * id)
850{
851 return (debug_entry_t *) (((char *) id->areas[id->active_area]
852 [id->active_pages[id->active_area]]) +
853 id->active_entries[id->active_area]);
854}
855
856/*
857 * debug_finish_entry:
858 * - set timestamp, caller address, cpu number etc.
859 */
860
861static inline void
862debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
863 int exception)
864{
865 active->id.stck = get_clock();
866 active->id.fields.cpuid = smp_processor_id();
867 active->caller = __builtin_return_address(0);
868 active->id.fields.exception = exception;
869 active->id.fields.level = level;
870 proceed_active_entry(id);
871 if(exception)
872 proceed_active_area(id);
873}
874
875static int debug_stoppable=1;
876static int debug_active=1;
877
878#define CTL_S390DBF_STOPPABLE 5678
879#define CTL_S390DBF_ACTIVE 5679
880
881/*
882 * proc handler for the running debug_active sysctl
883 * always allow read, allow write only if debug_stoppable is set or
884 * if debug_active is already off
885 */
886static int
887s390dbf_procactive(ctl_table *table, int write,
888 void __user *buffer, size_t *lenp, loff_t *ppos)
889{
890 if (!write || debug_stoppable || !debug_active)
891 return proc_dointvec(table, write, buffer, lenp, ppos);
892 else
893 return 0;
894}
895
896
897static struct ctl_table s390dbf_table[] = {
898 {
899 .procname = "debug_stoppable",
900 .data = &debug_stoppable,
901 .maxlen = sizeof(int),
902 .mode = S_IRUGO | S_IWUSR,
903 .proc_handler = proc_dointvec,
904 },
905 {
906 .procname = "debug_active",
907 .data = &debug_active,
908 .maxlen = sizeof(int),
909 .mode = S_IRUGO | S_IWUSR,
910 .proc_handler = s390dbf_procactive,
911 },
912 { }
913};
914
915static struct ctl_table s390dbf_dir_table[] = {
916 {
917 .procname = "s390dbf",
918 .maxlen = 0,
919 .mode = S_IRUGO | S_IXUGO,
920 .child = s390dbf_table,
921 },
922 { }
923};
924
925static struct ctl_table_header *s390dbf_sysctl_header;
926
927void
928debug_stop_all(void)
929{
930 if (debug_stoppable)
931 debug_active = 0;
932}
933
934
935/*
936 * debug_event_common:
937 * - write debug entry with given size
938 */
939
940debug_entry_t*
941debug_event_common(debug_info_t * id, int level, const void *buf, int len)
942{
943 unsigned long flags;
944 debug_entry_t *active;
945
946 if (!debug_active || !id->areas)
947 return NULL;
948 spin_lock_irqsave(&id->lock, flags);
949 active = get_active_entry(id);
950 memset(DEBUG_DATA(active), 0, id->buf_size);
951 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
952 debug_finish_entry(id, active, level, 0);
953 spin_unlock_irqrestore(&id->lock, flags);
954
955 return active;
956}
957
958/*
959 * debug_exception_common:
960 * - write debug entry with given size and switch to next debug area
961 */
962
963debug_entry_t
964*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
965{
966 unsigned long flags;
967 debug_entry_t *active;
968
969 if (!debug_active || !id->areas)
970 return NULL;
971 spin_lock_irqsave(&id->lock, flags);
972 active = get_active_entry(id);
973 memset(DEBUG_DATA(active), 0, id->buf_size);
974 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
975 debug_finish_entry(id, active, level, 1);
976 spin_unlock_irqrestore(&id->lock, flags);
977
978 return active;
979}
980
981/*
982 * counts arguments in format string for sprintf view
983 */
984
985static inline int
986debug_count_numargs(char *string)
987{
988 int numargs=0;
989
990 while(*string) {
991 if(*string++=='%')
992 numargs++;
993 }
994 return(numargs);
995}
996
997/*
998 * debug_sprintf_event:
999 */
1000
1001debug_entry_t*
1002debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1003{
1004 va_list ap;
1005 int numargs,idx;
1006 unsigned long flags;
1007 debug_sprintf_entry_t *curr_event;
1008 debug_entry_t *active;
1009
1010 if((!id) || (level > id->level))
1011 return NULL;
1012 if (!debug_active || !id->areas)
1013 return NULL;
1014 numargs=debug_count_numargs(string);
1015
1016 spin_lock_irqsave(&id->lock, flags);
1017 active = get_active_entry(id);
1018 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1019 va_start(ap,string);
1020 curr_event->string=string;
1021 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1022 curr_event->args[idx]=va_arg(ap,long);
1023 va_end(ap);
1024 debug_finish_entry(id, active, level, 0);
1025 spin_unlock_irqrestore(&id->lock, flags);
1026
1027 return active;
1028}
1029
1030/*
1031 * debug_sprintf_exception:
1032 */
1033
1034debug_entry_t*
1035debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1036{
1037 va_list ap;
1038 int numargs,idx;
1039 unsigned long flags;
1040 debug_sprintf_entry_t *curr_event;
1041 debug_entry_t *active;
1042
1043 if((!id) || (level > id->level))
1044 return NULL;
1045 if (!debug_active || !id->areas)
1046 return NULL;
1047
1048 numargs=debug_count_numargs(string);
1049
1050 spin_lock_irqsave(&id->lock, flags);
1051 active = get_active_entry(id);
1052 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1053 va_start(ap,string);
1054 curr_event->string=string;
1055 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1056 curr_event->args[idx]=va_arg(ap,long);
1057 va_end(ap);
1058 debug_finish_entry(id, active, level, 1);
1059 spin_unlock_irqrestore(&id->lock, flags);
1060
1061 return active;
1062}
1063
1064/*
1065 * debug_init:
1066 * - is called exactly once to initialize the debug feature
1067 */
1068
1069static int
1070__init debug_init(void)
1071{
1072 int rc = 0;
1073
1074 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1075 mutex_lock(&debug_mutex);
1076 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1077 initialized = 1;
1078 mutex_unlock(&debug_mutex);
1079
1080 return rc;
1081}
1082
1083/*
1084 * debug_register_view:
1085 */
1086
1087int
1088debug_register_view(debug_info_t * id, struct debug_view *view)
1089{
1090 int rc = 0;
1091 int i;
1092 unsigned long flags;
1093 mode_t mode;
1094 struct dentry *pde;
1095
1096 if (!id)
1097 goto out;
1098 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1099 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1100 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1101 if (!view->input_proc)
1102 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1103 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1104 id , &debug_file_ops);
1105 if (!pde){
1106 pr_err("Registering view %s/%s failed due to out of "
1107 "memory\n", id->name,view->name);
1108 rc = -1;
1109 goto out;
1110 }
1111 spin_lock_irqsave(&id->lock, flags);
1112 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1113 if (!id->views[i])
1114 break;
1115 }
1116 if (i == DEBUG_MAX_VIEWS) {
1117 pr_err("Registering view %s/%s would exceed the maximum "
1118 "number of views %i\n", id->name, view->name, i);
1119 debugfs_remove(pde);
1120 rc = -1;
1121 } else {
1122 id->views[i] = view;
1123 id->debugfs_entries[i] = pde;
1124 }
1125 spin_unlock_irqrestore(&id->lock, flags);
1126out:
1127 return rc;
1128}
1129
1130/*
1131 * debug_unregister_view:
1132 */
1133
1134int
1135debug_unregister_view(debug_info_t * id, struct debug_view *view)
1136{
1137 int rc = 0;
1138 int i;
1139 unsigned long flags;
1140
1141 if (!id)
1142 goto out;
1143 spin_lock_irqsave(&id->lock, flags);
1144 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1145 if (id->views[i] == view)
1146 break;
1147 }
1148 if (i == DEBUG_MAX_VIEWS)
1149 rc = -1;
1150 else {
1151 debugfs_remove(id->debugfs_entries[i]);
1152 id->views[i] = NULL;
1153 }
1154 spin_unlock_irqrestore(&id->lock, flags);
1155out:
1156 return rc;
1157}
1158
1159static inline char *
1160debug_get_user_string(const char __user *user_buf, size_t user_len)
1161{
1162 char* buffer;
1163
1164 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1165 if (!buffer)
1166 return ERR_PTR(-ENOMEM);
1167 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1168 kfree(buffer);
1169 return ERR_PTR(-EFAULT);
1170 }
1171 /* got the string, now strip linefeed. */
1172 if (buffer[user_len - 1] == '\n')
1173 buffer[user_len - 1] = 0;
1174 else
1175 buffer[user_len] = 0;
1176 return buffer;
1177}
1178
1179static inline int
1180debug_get_uint(char *buf)
1181{
1182 int rc;
1183
1184 buf = skip_spaces(buf);
1185 rc = simple_strtoul(buf, &buf, 10);
1186 if(*buf){
1187 rc = -EINVAL;
1188 }
1189 return rc;
1190}
1191
1192/*
1193 * functions for debug-views
1194 ***********************************
1195*/
1196
1197/*
1198 * prints out actual debug level
1199 */
1200
1201static int
1202debug_prolog_pages_fn(debug_info_t * id,
1203 struct debug_view *view, char *out_buf)
1204{
1205 return sprintf(out_buf, "%i\n", id->pages_per_area);
1206}
1207
1208/*
1209 * reads new size (number of pages per debug area)
1210 */
1211
1212static int
1213debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1214 struct file *file, const char __user *user_buf,
1215 size_t user_len, loff_t * offset)
1216{
1217 char *str;
1218 int rc,new_pages;
1219
1220 if (user_len > 0x10000)
1221 user_len = 0x10000;
1222 if (*offset != 0){
1223 rc = -EPIPE;
1224 goto out;
1225 }
1226 str = debug_get_user_string(user_buf,user_len);
1227 if(IS_ERR(str)){
1228 rc = PTR_ERR(str);
1229 goto out;
1230 }
1231 new_pages = debug_get_uint(str);
1232 if(new_pages < 0){
1233 rc = -EINVAL;
1234 goto free_str;
1235 }
1236 rc = debug_set_size(id,id->nr_areas, new_pages);
1237 if(rc != 0){
1238 rc = -EINVAL;
1239 goto free_str;
1240 }
1241 rc = user_len;
1242free_str:
1243 kfree(str);
1244out:
1245 *offset += user_len;
1246 return rc; /* number of input characters */
1247}
1248
1249/*
1250 * prints out actual debug level
1251 */
1252
1253static int
1254debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1255{
1256 int rc = 0;
1257
1258 if(id->level == DEBUG_OFF_LEVEL) {
1259 rc = sprintf(out_buf,"-\n");
1260 }
1261 else {
1262 rc = sprintf(out_buf, "%i\n", id->level);
1263 }
1264 return rc;
1265}
1266
1267/*
1268 * reads new debug level
1269 */
1270
1271static int
1272debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1273 struct file *file, const char __user *user_buf,
1274 size_t user_len, loff_t * offset)
1275{
1276 char *str;
1277 int rc,new_level;
1278
1279 if (user_len > 0x10000)
1280 user_len = 0x10000;
1281 if (*offset != 0){
1282 rc = -EPIPE;
1283 goto out;
1284 }
1285 str = debug_get_user_string(user_buf,user_len);
1286 if(IS_ERR(str)){
1287 rc = PTR_ERR(str);
1288 goto out;
1289 }
1290 if(str[0] == '-'){
1291 debug_set_level(id, DEBUG_OFF_LEVEL);
1292 rc = user_len;
1293 goto free_str;
1294 } else {
1295 new_level = debug_get_uint(str);
1296 }
1297 if(new_level < 0) {
1298 pr_warning("%s is not a valid level for a debug "
1299 "feature\n", str);
1300 rc = -EINVAL;
1301 } else {
1302 debug_set_level(id, new_level);
1303 rc = user_len;
1304 }
1305free_str:
1306 kfree(str);
1307out:
1308 *offset += user_len;
1309 return rc; /* number of input characters */
1310}
1311
1312
1313/*
1314 * flushes debug areas
1315 */
1316
1317static void debug_flush(debug_info_t* id, int area)
1318{
1319 unsigned long flags;
1320 int i,j;
1321
1322 if(!id || !id->areas)
1323 return;
1324 spin_lock_irqsave(&id->lock,flags);
1325 if(area == DEBUG_FLUSH_ALL){
1326 id->active_area = 0;
1327 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1328 for (i = 0; i < id->nr_areas; i++) {
1329 id->active_pages[i] = 0;
1330 for(j = 0; j < id->pages_per_area; j++) {
1331 memset(id->areas[i][j], 0, PAGE_SIZE);
1332 }
1333 }
1334 } else if(area >= 0 && area < id->nr_areas) {
1335 id->active_entries[area] = 0;
1336 id->active_pages[area] = 0;
1337 for(i = 0; i < id->pages_per_area; i++) {
1338 memset(id->areas[area][i],0,PAGE_SIZE);
1339 }
1340 }
1341 spin_unlock_irqrestore(&id->lock,flags);
1342}
1343
1344/*
1345 * view function: flushes debug areas
1346 */
1347
1348static int
1349debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1350 struct file *file, const char __user *user_buf,
1351 size_t user_len, loff_t * offset)
1352{
1353 char input_buf[1];
1354 int rc = user_len;
1355
1356 if (user_len > 0x10000)
1357 user_len = 0x10000;
1358 if (*offset != 0){
1359 rc = -EPIPE;
1360 goto out;
1361 }
1362 if (copy_from_user(input_buf, user_buf, 1)){
1363 rc = -EFAULT;
1364 goto out;
1365 }
1366 if(input_buf[0] == '-') {
1367 debug_flush(id, DEBUG_FLUSH_ALL);
1368 goto out;
1369 }
1370 if (isdigit(input_buf[0])) {
1371 int area = ((int) input_buf[0] - (int) '0');
1372 debug_flush(id, area);
1373 goto out;
1374 }
1375
1376 pr_info("Flushing debug data failed because %c is not a valid "
1377 "area\n", input_buf[0]);
1378
1379out:
1380 *offset += user_len;
1381 return rc; /* number of input characters */
1382}
1383
1384/*
1385 * prints debug header in raw format
1386 */
1387
1388static int
1389debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1390 int area, debug_entry_t * entry, char *out_buf)
1391{
1392 int rc;
1393
1394 rc = sizeof(debug_entry_t);
1395 memcpy(out_buf,entry,sizeof(debug_entry_t));
1396 return rc;
1397}
1398
1399/*
1400 * prints debug data in raw format
1401 */
1402
1403static int
1404debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1405 char *out_buf, const char *in_buf)
1406{
1407 int rc;
1408
1409 rc = id->buf_size;
1410 memcpy(out_buf, in_buf, id->buf_size);
1411 return rc;
1412}
1413
1414/*
1415 * prints debug data in hex/ascii format
1416 */
1417
1418static int
1419debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1420 char *out_buf, const char *in_buf)
1421{
1422 int i, rc = 0;
1423
1424 for (i = 0; i < id->buf_size; i++) {
1425 rc += sprintf(out_buf + rc, "%02x ",
1426 ((unsigned char *) in_buf)[i]);
1427 }
1428 rc += sprintf(out_buf + rc, "| ");
1429 for (i = 0; i < id->buf_size; i++) {
1430 unsigned char c = in_buf[i];
1431 if (!isprint(c))
1432 rc += sprintf(out_buf + rc, ".");
1433 else
1434 rc += sprintf(out_buf + rc, "%c", c);
1435 }
1436 rc += sprintf(out_buf + rc, "\n");
1437 return rc;
1438}
1439
1440/*
1441 * prints header for debug entry
1442 */
1443
1444int
1445debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1446 int area, debug_entry_t * entry, char *out_buf)
1447{
1448 struct timespec time_spec;
1449 char *except_str;
1450 unsigned long caller;
1451 int rc = 0;
1452 unsigned int level;
1453
1454 level = entry->id.fields.level;
1455 stck_to_timespec(entry->id.stck, &time_spec);
1456
1457 if (entry->id.fields.exception)
1458 except_str = "*";
1459 else
1460 except_str = "-";
1461 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1462 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1463 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1464 except_str, entry->id.fields.cpuid, (void *) caller);
1465 return rc;
1466}
1467
1468/*
1469 * prints debug data sprintf-formated:
1470 * debug_sprinf_event/exception calls must be used together with this view
1471 */
1472
1473#define DEBUG_SPRINTF_MAX_ARGS 10
1474
1475static int
1476debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1477 char *out_buf, debug_sprintf_entry_t *curr_event)
1478{
1479 int num_longs, num_used_args = 0,i, rc = 0;
1480 int index[DEBUG_SPRINTF_MAX_ARGS];
1481
1482 /* count of longs fit into one entry */
1483 num_longs = id->buf_size / sizeof(long);
1484
1485 if(num_longs < 1)
1486 goto out; /* bufsize of entry too small */
1487 if(num_longs == 1) {
1488 /* no args, we use only the string */
1489 strcpy(out_buf, curr_event->string);
1490 rc = strlen(curr_event->string);
1491 goto out;
1492 }
1493
1494 /* number of arguments used for sprintf (without the format string) */
1495 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1496
1497 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1498
1499 for(i = 0; i < num_used_args; i++)
1500 index[i] = i;
1501
1502 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1503 curr_event->args[index[1]], curr_event->args[index[2]],
1504 curr_event->args[index[3]], curr_event->args[index[4]],
1505 curr_event->args[index[5]], curr_event->args[index[6]],
1506 curr_event->args[index[7]], curr_event->args[index[8]],
1507 curr_event->args[index[9]]);
1508
1509out:
1510
1511 return rc;
1512}
1513
1514/*
1515 * clean up module
1516 */
1517static void __exit debug_exit(void)
1518{
1519 debugfs_remove(debug_debugfs_root_entry);
1520 unregister_sysctl_table(s390dbf_sysctl_header);
1521 return;
1522}
1523
1524/*
1525 * module definitions
1526 */
1527postcore_initcall(debug_init);
1528module_exit(debug_exit);
1529MODULE_LICENSE("GPL");
1530
1531EXPORT_SYMBOL(debug_register);
1532EXPORT_SYMBOL(debug_unregister);
1533EXPORT_SYMBOL(debug_set_level);
1534EXPORT_SYMBOL(debug_stop_all);
1535EXPORT_SYMBOL(debug_register_view);
1536EXPORT_SYMBOL(debug_unregister_view);
1537EXPORT_SYMBOL(debug_event_common);
1538EXPORT_SYMBOL(debug_exception_common);
1539EXPORT_SYMBOL(debug_hex_ascii_view);
1540EXPORT_SYMBOL(debug_raw_view);
1541EXPORT_SYMBOL(debug_dflt_header_fn);
1542EXPORT_SYMBOL(debug_sprintf_view);
1543EXPORT_SYMBOL(debug_sprintf_exception);
1544EXPORT_SYMBOL(debug_sprintf_event);