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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);
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);