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[S390] s390dbf: Remove needless check for NULL pointer.
[linux-2.6/btrfs-unstable.git] / arch / s390 / kernel / debug.c
blobbe8bceaf37d96660e9b5e3ecd56d689fd86bc3e6
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/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
37 typedef 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
53 typedef 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 extern void tod_to_timeval(uint64_t todval, struct timespec *xtime);
67
68 /* internal function prototyes */
69
70 static int debug_init(void);
71 static ssize_t debug_output(struct file *file, char __user *user_buf,
72 size_t user_len, loff_t * offset);
73 static ssize_t debug_input(struct file *file, const char __user *user_buf,
74 size_t user_len, loff_t * offset);
75 static int debug_open(struct inode *inode, struct file *file);
76 static int debug_close(struct inode *inode, struct file *file);
77 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
78 int nr_areas, int buf_size, mode_t mode);
79 static void debug_info_get(debug_info_t *);
80 static void debug_info_put(debug_info_t *);
81 static int debug_prolog_level_fn(debug_info_t * id,
82 struct debug_view *view, char *out_buf);
83 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
84 struct file *file, const char __user *user_buf,
85 size_t user_buf_size, loff_t * offset);
86 static int debug_prolog_pages_fn(debug_info_t * id,
87 struct debug_view *view, char *out_buf);
88 static int debug_input_pages_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);
91 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
92 struct file *file, const char __user *user_buf,
93 size_t user_buf_size, loff_t * offset);
94 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
95 char *out_buf, const char *in_buf);
96 static int debug_raw_format_fn(debug_info_t * id,
97 struct debug_view *view, char *out_buf,
98 const char *in_buf);
99 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
100 int area, debug_entry_t * entry, char *out_buf);
101
102 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
103 char *out_buf, debug_sprintf_entry_t *curr_event);
104
105 /* globals */
106
107 struct debug_view debug_raw_view = {
108 "raw",
109 NULL,
110 &debug_raw_header_fn,
111 &debug_raw_format_fn,
112 NULL,
113 NULL
114 };
115
116 struct debug_view debug_hex_ascii_view = {
117 "hex_ascii",
118 NULL,
119 &debug_dflt_header_fn,
120 &debug_hex_ascii_format_fn,
121 NULL,
122 NULL
123 };
124
125 static 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
134 static 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
143 static struct debug_view debug_flush_view = {
144 "flush",
145 NULL,
146 NULL,
147 NULL,
148 &debug_input_flush_fn,
149 NULL
150 };
151
152 struct 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 };
160
161 /* used by dump analysis tools to determine version of debug feature */
162 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
163
164 /* static globals */
165
166 static debug_info_t *debug_area_first = NULL;
167 static debug_info_t *debug_area_last = NULL;
168 static DEFINE_MUTEX(debug_mutex);
169
170 static int initialized;
171
172 static const struct file_operations debug_file_ops = {
173 .owner = THIS_MODULE,
174 .read = debug_output,
175 .write = debug_input,
176 .open = debug_open,
177 .release = debug_close,
178 };
179
180 static 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
190 static debug_entry_t***
191 debug_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
220 fail_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);
228 fail_malloc_areas:
229 return NULL;
230
231 }
232
233
234 /*
235 * debug_info_alloc
236 * - alloc new debug-info
237 */
238
239 static debug_info_t*
240 debug_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
281 fail_malloc_areas:
282 kfree(rc->active_pages);
283 fail_malloc_active_pages:
284 kfree(rc->active_entries);
285 fail_malloc_active_entries:
286 kfree(rc);
287 fail_malloc_rc:
288 return NULL;
289 }
290
291 /*
292 * debug_areas_free
293 * - free all debug areas
294 */
295
296 static void
297 debug_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
318 static void
319 debug_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
331 static debug_info_t*
332 debug_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);
362 out:
363 return rc;
364 }
365
366 /*
367 * debug_info_copy
368 * - copy debug-info
369 */
370
371 static debug_info_t*
372 debug_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 }
402 out:
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
412 static void
413 debug_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
424 static void
425 debug_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
453 static int
454 debug_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));
479 out:
480 return len;
481 }
482
483 /*
484 * debug_next_entry:
485 * - goto next entry in p_info
486 */
487
488 static inline int
489 debug_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 }
515 out:
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
525 static ssize_t
526 debug_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 }
564 out:
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
577 static ssize_t
578 debug_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
603 static int
604 debug_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
625 found:
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 out:
660 mutex_unlock(&debug_mutex);
661 return rc;
662 }
663
664 /*
665 * debug_close:
666 * - called for user close()
667 * - deletes private_data area of the file handle
668 */
669
670 static int
671 debug_close(struct inode *inode, struct file *file)
672 {
673 file_private_info_t *p_info;
674 p_info = (file_private_info_t *) file->private_data;
675 if(p_info->debug_info_snap)
676 debug_info_free(p_info->debug_info_snap);
677 debug_info_put(p_info->debug_info_org);
678 kfree(file->private_data);
679 return 0; /* success */
680 }
681
682 /*
683 * debug_register_mode:
684 * - Creates and initializes debug area for the caller
685 * The mode parameter allows to specify access rights for the s390dbf files
686 * - Returns handle for debug area
687 */
688
689 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
690 int nr_areas, int buf_size, mode_t mode,
691 uid_t uid, gid_t gid)
692 {
693 debug_info_t *rc = NULL;
694
695 /* Since debugfs currently does not support uid/gid other than root, */
696 /* we do not allow gid/uid != 0 until we get support for that. */
697 if ((uid != 0) || (gid != 0))
698 pr_warning("Root becomes the owner of all s390dbf files "
699 "in sysfs\n");
700 BUG_ON(!initialized);
701 mutex_lock(&debug_mutex);
702
703 /* create new debug_info */
704
705 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
706 if(!rc)
707 goto out;
708 debug_register_view(rc, &debug_level_view);
709 debug_register_view(rc, &debug_flush_view);
710 debug_register_view(rc, &debug_pages_view);
711 out:
712 if (!rc){
713 pr_err("Registering debug feature %s failed\n", name);
714 }
715 mutex_unlock(&debug_mutex);
716 return rc;
717 }
718 EXPORT_SYMBOL(debug_register_mode);
719
720 /*
721 * debug_register:
722 * - creates and initializes debug area for the caller
723 * - returns handle for debug area
724 */
725
726 debug_info_t *debug_register(const char *name, int pages_per_area,
727 int nr_areas, int buf_size)
728 {
729 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
730 S_IRUSR | S_IWUSR, 0, 0);
731 }
732
733 /*
734 * debug_unregister:
735 * - give back debug area
736 */
737
738 void
739 debug_unregister(debug_info_t * id)
740 {
741 if (!id)
742 goto out;
743 mutex_lock(&debug_mutex);
744 debug_info_put(id);
745 mutex_unlock(&debug_mutex);
746
747 out:
748 return;
749 }
750
751 /*
752 * debug_set_size:
753 * - set area size (number of pages) and number of areas
754 */
755 static int
756 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
757 {
758 unsigned long flags;
759 debug_entry_t *** new_areas;
760 int rc=0;
761
762 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
763 return -EINVAL;
764 if(pages_per_area > 0){
765 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
766 if(!new_areas) {
767 pr_info("Allocating memory for %i pages failed\n",
768 pages_per_area);
769 rc = -ENOMEM;
770 goto out;
771 }
772 } else {
773 new_areas = NULL;
774 }
775 spin_lock_irqsave(&id->lock,flags);
776 debug_areas_free(id);
777 id->areas = new_areas;
778 id->nr_areas = nr_areas;
779 id->pages_per_area = pages_per_area;
780 id->active_area = 0;
781 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
782 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
783 spin_unlock_irqrestore(&id->lock,flags);
784 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
785 out:
786 return rc;
787 }
788
789 /*
790 * debug_set_level:
791 * - set actual debug level
792 */
793
794 void
795 debug_set_level(debug_info_t* id, int new_level)
796 {
797 unsigned long flags;
798 if(!id)
799 return;
800 spin_lock_irqsave(&id->lock,flags);
801 if(new_level == DEBUG_OFF_LEVEL){
802 id->level = DEBUG_OFF_LEVEL;
803 pr_info("%s: switched off\n",id->name);
804 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
805 pr_info("%s: level %i is out of range (%i - %i)\n",
806 id->name, new_level, 0, DEBUG_MAX_LEVEL);
807 } else {
808 id->level = new_level;
809 }
810 spin_unlock_irqrestore(&id->lock,flags);
811 }
812
813
814 /*
815 * proceed_active_entry:
816 * - set active entry to next in the ring buffer
817 */
818
819 static inline void
820 proceed_active_entry(debug_info_t * id)
821 {
822 if ((id->active_entries[id->active_area] += id->entry_size)
823 > (PAGE_SIZE - id->entry_size)){
824 id->active_entries[id->active_area] = 0;
825 id->active_pages[id->active_area] =
826 (id->active_pages[id->active_area] + 1) %
827 id->pages_per_area;
828 }
829 }
830
831 /*
832 * proceed_active_area:
833 * - set active area to next in the ring buffer
834 */
835
836 static inline void
837 proceed_active_area(debug_info_t * id)
838 {
839 id->active_area++;
840 id->active_area = id->active_area % id->nr_areas;
841 }
842
843 /*
844 * get_active_entry:
845 */
846
847 static inline debug_entry_t*
848 get_active_entry(debug_info_t * id)
849 {
850 return (debug_entry_t *) (((char *) id->areas[id->active_area]
851 [id->active_pages[id->active_area]]) +
852 id->active_entries[id->active_area]);
853 }
854
855 /*
856 * debug_finish_entry:
857 * - set timestamp, caller address, cpu number etc.
858 */
859
860 static inline void
861 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
862 int exception)
863 {
864 active->id.stck = get_clock();
865 active->id.fields.cpuid = smp_processor_id();
866 active->caller = __builtin_return_address(0);
867 active->id.fields.exception = exception;
868 active->id.fields.level = level;
869 proceed_active_entry(id);
870 if(exception)
871 proceed_active_area(id);
872 }
873
874 static int debug_stoppable=1;
875 static int debug_active=1;
876
877 #define CTL_S390DBF_STOPPABLE 5678
878 #define CTL_S390DBF_ACTIVE 5679
879
880 /*
881 * proc handler for the running debug_active sysctl
882 * always allow read, allow write only if debug_stoppable is set or
883 * if debug_active is already off
884 */
885 static int
886 s390dbf_procactive(ctl_table *table, int write, struct file *filp,
887 void __user *buffer, size_t *lenp, loff_t *ppos)
888 {
889 if (!write || debug_stoppable || !debug_active)
890 return proc_dointvec(table, write, filp, buffer, lenp, ppos);
891 else
892 return 0;
893 }
894
895
896 static struct ctl_table s390dbf_table[] = {
897 {
898 .ctl_name = CTL_S390DBF_STOPPABLE,
899 .procname = "debug_stoppable",
900 .data = &debug_stoppable,
901 .maxlen = sizeof(int),
902 .mode = S_IRUGO | S_IWUSR,
903 .proc_handler = &proc_dointvec,
904 .strategy = &sysctl_intvec,
905 },
906 {
907 .ctl_name = CTL_S390DBF_ACTIVE,
908 .procname = "debug_active",
909 .data = &debug_active,
910 .maxlen = sizeof(int),
911 .mode = S_IRUGO | S_IWUSR,
912 .proc_handler = &s390dbf_procactive,
913 .strategy = &sysctl_intvec,
914 },
915 { .ctl_name = 0 }
916 };
917
918 static struct ctl_table s390dbf_dir_table[] = {
919 {
920 .ctl_name = CTL_S390DBF,
921 .procname = "s390dbf",
922 .maxlen = 0,
923 .mode = S_IRUGO | S_IXUGO,
924 .child = s390dbf_table,
925 },
926 { .ctl_name = 0 }
927 };
928
929 static struct ctl_table_header *s390dbf_sysctl_header;
930
931 void
932 debug_stop_all(void)
933 {
934 if (debug_stoppable)
935 debug_active = 0;
936 }
937
938
939 /*
940 * debug_event_common:
941 * - write debug entry with given size
942 */
943
944 debug_entry_t*
945 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
946 {
947 unsigned long flags;
948 debug_entry_t *active;
949
950 if (!debug_active || !id->areas)
951 return NULL;
952 spin_lock_irqsave(&id->lock, flags);
953 active = get_active_entry(id);
954 memset(DEBUG_DATA(active), 0, id->buf_size);
955 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
956 debug_finish_entry(id, active, level, 0);
957 spin_unlock_irqrestore(&id->lock, flags);
958
959 return active;
960 }
961
962 /*
963 * debug_exception_common:
964 * - write debug entry with given size and switch to next debug area
965 */
966
967 debug_entry_t
968 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
969 {
970 unsigned long flags;
971 debug_entry_t *active;
972
973 if (!debug_active || !id->areas)
974 return NULL;
975 spin_lock_irqsave(&id->lock, flags);
976 active = get_active_entry(id);
977 memset(DEBUG_DATA(active), 0, id->buf_size);
978 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
979 debug_finish_entry(id, active, level, 1);
980 spin_unlock_irqrestore(&id->lock, flags);
981
982 return active;
983 }
984
985 /*
986 * counts arguments in format string for sprintf view
987 */
988
989 static inline int
990 debug_count_numargs(char *string)
991 {
992 int numargs=0;
993
994 while(*string) {
995 if(*string++=='%')
996 numargs++;
997 }
998 return(numargs);
999 }
1000
1001 /*
1002 * debug_sprintf_event:
1003 */
1004
1005 debug_entry_t*
1006 debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1007 {
1008 va_list ap;
1009 int numargs,idx;
1010 unsigned long flags;
1011 debug_sprintf_entry_t *curr_event;
1012 debug_entry_t *active;
1013
1014 if((!id) || (level > id->level))
1015 return NULL;
1016 if (!debug_active || !id->areas)
1017 return NULL;
1018 numargs=debug_count_numargs(string);
1019
1020 spin_lock_irqsave(&id->lock, flags);
1021 active = get_active_entry(id);
1022 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1023 va_start(ap,string);
1024 curr_event->string=string;
1025 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1026 curr_event->args[idx]=va_arg(ap,long);
1027 va_end(ap);
1028 debug_finish_entry(id, active, level, 0);
1029 spin_unlock_irqrestore(&id->lock, flags);
1030
1031 return active;
1032 }
1033
1034 /*
1035 * debug_sprintf_exception:
1036 */
1037
1038 debug_entry_t*
1039 debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1040 {
1041 va_list ap;
1042 int numargs,idx;
1043 unsigned long flags;
1044 debug_sprintf_entry_t *curr_event;
1045 debug_entry_t *active;
1046
1047 if((!id) || (level > id->level))
1048 return NULL;
1049 if (!debug_active || !id->areas)
1050 return NULL;
1051
1052 numargs=debug_count_numargs(string);
1053
1054 spin_lock_irqsave(&id->lock, flags);
1055 active = get_active_entry(id);
1056 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1057 va_start(ap,string);
1058 curr_event->string=string;
1059 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1060 curr_event->args[idx]=va_arg(ap,long);
1061 va_end(ap);
1062 debug_finish_entry(id, active, level, 1);
1063 spin_unlock_irqrestore(&id->lock, flags);
1064
1065 return active;
1066 }
1067
1068 /*
1069 * debug_init:
1070 * - is called exactly once to initialize the debug feature
1071 */
1072
1073 static int
1074 __init debug_init(void)
1075 {
1076 int rc = 0;
1077
1078 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1079 mutex_lock(&debug_mutex);
1080 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1081 initialized = 1;
1082 mutex_unlock(&debug_mutex);
1083
1084 return rc;
1085 }
1086
1087 /*
1088 * debug_register_view:
1089 */
1090
1091 int
1092 debug_register_view(debug_info_t * id, struct debug_view *view)
1093 {
1094 int rc = 0;
1095 int i;
1096 unsigned long flags;
1097 mode_t mode;
1098 struct dentry *pde;
1099
1100 if (!id)
1101 goto out;
1102 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1103 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1104 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1105 if (!view->input_proc)
1106 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1107 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1108 id , &debug_file_ops);
1109 if (!pde){
1110 pr_err("Registering view %s/%s failed due to out of "
1111 "memory\n", id->name,view->name);
1112 rc = -1;
1113 goto out;
1114 }
1115 spin_lock_irqsave(&id->lock, flags);
1116 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1117 if (!id->views[i])
1118 break;
1119 }
1120 if (i == DEBUG_MAX_VIEWS) {
1121 pr_err("Registering view %s/%s would exceed the maximum "
1122 "number of views %i\n", id->name, view->name, i);
1123 debugfs_remove(pde);
1124 rc = -1;
1125 } else {
1126 id->views[i] = view;
1127 id->debugfs_entries[i] = pde;
1128 }
1129 spin_unlock_irqrestore(&id->lock, flags);
1130 out:
1131 return rc;
1132 }
1133
1134 /*
1135 * debug_unregister_view:
1136 */
1137
1138 int
1139 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1140 {
1141 int rc = 0;
1142 int i;
1143 unsigned long flags;
1144
1145 if (!id)
1146 goto out;
1147 spin_lock_irqsave(&id->lock, flags);
1148 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1149 if (id->views[i] == view)
1150 break;
1151 }
1152 if (i == DEBUG_MAX_VIEWS)
1153 rc = -1;
1154 else {
1155 debugfs_remove(id->debugfs_entries[i]);
1156 id->views[i] = NULL;
1157 }
1158 spin_unlock_irqrestore(&id->lock, flags);
1159 out:
1160 return rc;
1161 }
1162
1163 static inline char *
1164 debug_get_user_string(const char __user *user_buf, size_t user_len)
1165 {
1166 char* buffer;
1167
1168 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1169 if (!buffer)
1170 return ERR_PTR(-ENOMEM);
1171 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1172 kfree(buffer);
1173 return ERR_PTR(-EFAULT);
1174 }
1175 /* got the string, now strip linefeed. */
1176 if (buffer[user_len - 1] == '\n')
1177 buffer[user_len - 1] = 0;
1178 else
1179 buffer[user_len] = 0;
1180 return buffer;
1181 }
1182
1183 static inline int
1184 debug_get_uint(char *buf)
1185 {
1186 int rc;
1187
1188 for(; isspace(*buf); buf++);
1189 rc = simple_strtoul(buf, &buf, 10);
1190 if(*buf){
1191 rc = -EINVAL;
1192 }
1193 return rc;
1194 }
1195
1196 /*
1197 * functions for debug-views
1198 ***********************************
1199 */
1200
1201 /*
1202 * prints out actual debug level
1203 */
1204
1205 static int
1206 debug_prolog_pages_fn(debug_info_t * id,
1207 struct debug_view *view, char *out_buf)
1208 {
1209 return sprintf(out_buf, "%i\n", id->pages_per_area);
1210 }
1211
1212 /*
1213 * reads new size (number of pages per debug area)
1214 */
1215
1216 static int
1217 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1218 struct file *file, const char __user *user_buf,
1219 size_t user_len, loff_t * offset)
1220 {
1221 char *str;
1222 int rc,new_pages;
1223
1224 if (user_len > 0x10000)
1225 user_len = 0x10000;
1226 if (*offset != 0){
1227 rc = -EPIPE;
1228 goto out;
1229 }
1230 str = debug_get_user_string(user_buf,user_len);
1231 if(IS_ERR(str)){
1232 rc = PTR_ERR(str);
1233 goto out;
1234 }
1235 new_pages = debug_get_uint(str);
1236 if(new_pages < 0){
1237 rc = -EINVAL;
1238 goto free_str;
1239 }
1240 rc = debug_set_size(id,id->nr_areas, new_pages);
1241 if(rc != 0){
1242 rc = -EINVAL;
1243 goto free_str;
1244 }
1245 rc = user_len;
1246 free_str:
1247 kfree(str);
1248 out:
1249 *offset += user_len;
1250 return rc; /* number of input characters */
1251 }
1252
1253 /*
1254 * prints out actual debug level
1255 */
1256
1257 static int
1258 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1259 {
1260 int rc = 0;
1261
1262 if(id->level == DEBUG_OFF_LEVEL) {
1263 rc = sprintf(out_buf,"-\n");
1264 }
1265 else {
1266 rc = sprintf(out_buf, "%i\n", id->level);
1267 }
1268 return rc;
1269 }
1270
1271 /*
1272 * reads new debug level
1273 */
1274
1275 static int
1276 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1277 struct file *file, const char __user *user_buf,
1278 size_t user_len, loff_t * offset)
1279 {
1280 char *str;
1281 int rc,new_level;
1282
1283 if (user_len > 0x10000)
1284 user_len = 0x10000;
1285 if (*offset != 0){
1286 rc = -EPIPE;
1287 goto out;
1288 }
1289 str = debug_get_user_string(user_buf,user_len);
1290 if(IS_ERR(str)){
1291 rc = PTR_ERR(str);
1292 goto out;
1293 }
1294 if(str[0] == '-'){
1295 debug_set_level(id, DEBUG_OFF_LEVEL);
1296 rc = user_len;
1297 goto free_str;
1298 } else {
1299 new_level = debug_get_uint(str);
1300 }
1301 if(new_level < 0) {
1302 pr_warning("%s is not a valid level for a debug "
1303 "feature\n", str);
1304 rc = -EINVAL;
1305 } else {
1306 debug_set_level(id, new_level);
1307 rc = user_len;
1308 }
1309 free_str:
1310 kfree(str);
1311 out:
1312 *offset += user_len;
1313 return rc; /* number of input characters */
1314 }
1315
1316
1317 /*
1318 * flushes debug areas
1319 */
1320
1321 static void debug_flush(debug_info_t* id, int area)
1322 {
1323 unsigned long flags;
1324 int i,j;
1325
1326 if(!id || !id->areas)
1327 return;
1328 spin_lock_irqsave(&id->lock,flags);
1329 if(area == DEBUG_FLUSH_ALL){
1330 id->active_area = 0;
1331 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1332 for (i = 0; i < id->nr_areas; i++) {
1333 id->active_pages[i] = 0;
1334 for(j = 0; j < id->pages_per_area; j++) {
1335 memset(id->areas[i][j], 0, PAGE_SIZE);
1336 }
1337 }
1338 } else if(area >= 0 && area < id->nr_areas) {
1339 id->active_entries[area] = 0;
1340 id->active_pages[area] = 0;
1341 for(i = 0; i < id->pages_per_area; i++) {
1342 memset(id->areas[area][i],0,PAGE_SIZE);
1343 }
1344 }
1345 spin_unlock_irqrestore(&id->lock,flags);
1346 }
1347
1348 /*
1349 * view function: flushes debug areas
1350 */
1351
1352 static int
1353 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1354 struct file *file, const char __user *user_buf,
1355 size_t user_len, loff_t * offset)
1356 {
1357 char input_buf[1];
1358 int rc = user_len;
1359
1360 if (user_len > 0x10000)
1361 user_len = 0x10000;
1362 if (*offset != 0){
1363 rc = -EPIPE;
1364 goto out;
1365 }
1366 if (copy_from_user(input_buf, user_buf, 1)){
1367 rc = -EFAULT;
1368 goto out;
1369 }
1370 if(input_buf[0] == '-') {
1371 debug_flush(id, DEBUG_FLUSH_ALL);
1372 goto out;
1373 }
1374 if (isdigit(input_buf[0])) {
1375 int area = ((int) input_buf[0] - (int) '0');
1376 debug_flush(id, area);
1377 goto out;
1378 }
1379
1380 pr_info("Flushing debug data failed because %c is not a valid "
1381 "area\n", input_buf[0]);
1382
1383 out:
1384 *offset += user_len;
1385 return rc; /* number of input characters */
1386 }
1387
1388 /*
1389 * prints debug header in raw format
1390 */
1391
1392 static int
1393 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1394 int area, debug_entry_t * entry, char *out_buf)
1395 {
1396 int rc;
1397
1398 rc = sizeof(debug_entry_t);
1399 memcpy(out_buf,entry,sizeof(debug_entry_t));
1400 return rc;
1401 }
1402
1403 /*
1404 * prints debug data in raw format
1405 */
1406
1407 static int
1408 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1409 char *out_buf, const char *in_buf)
1410 {
1411 int rc;
1412
1413 rc = id->buf_size;
1414 memcpy(out_buf, in_buf, id->buf_size);
1415 return rc;
1416 }
1417
1418 /*
1419 * prints debug data in hex/ascii format
1420 */
1421
1422 static int
1423 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1424 char *out_buf, const char *in_buf)
1425 {
1426 int i, rc = 0;
1427
1428 for (i = 0; i < id->buf_size; i++) {
1429 rc += sprintf(out_buf + rc, "%02x ",
1430 ((unsigned char *) in_buf)[i]);
1431 }
1432 rc += sprintf(out_buf + rc, "| ");
1433 for (i = 0; i < id->buf_size; i++) {
1434 unsigned char c = in_buf[i];
1435 if (!isprint(c))
1436 rc += sprintf(out_buf + rc, ".");
1437 else
1438 rc += sprintf(out_buf + rc, "%c", c);
1439 }
1440 rc += sprintf(out_buf + rc, "\n");
1441 return rc;
1442 }
1443
1444 /*
1445 * prints header for debug entry
1446 */
1447
1448 int
1449 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1450 int area, debug_entry_t * entry, char *out_buf)
1451 {
1452 struct timespec time_spec;
1453 unsigned long long time;
1454 char *except_str;
1455 unsigned long caller;
1456 int rc = 0;
1457 unsigned int level;
1458
1459 level = entry->id.fields.level;
1460 time = entry->id.stck;
1461 /* adjust todclock to 1970 */
1462 time -= 0x8126d60e46000000LL - (0x3c26700LL * 1000000 * 4096);
1463 tod_to_timeval(time, &time_spec);
1464
1465 if (entry->id.fields.exception)
1466 except_str = "*";
1467 else
1468 except_str = "-";
1469 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1470 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1471 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1472 except_str, entry->id.fields.cpuid, (void *) caller);
1473 return rc;
1474 }
1475
1476 /*
1477 * prints debug data sprintf-formated:
1478 * debug_sprinf_event/exception calls must be used together with this view
1479 */
1480
1481 #define DEBUG_SPRINTF_MAX_ARGS 10
1482
1483 static int
1484 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1485 char *out_buf, debug_sprintf_entry_t *curr_event)
1486 {
1487 int num_longs, num_used_args = 0,i, rc = 0;
1488 int index[DEBUG_SPRINTF_MAX_ARGS];
1489
1490 /* count of longs fit into one entry */
1491 num_longs = id->buf_size / sizeof(long);
1492
1493 if(num_longs < 1)
1494 goto out; /* bufsize of entry too small */
1495 if(num_longs == 1) {
1496 /* no args, we use only the string */
1497 strcpy(out_buf, curr_event->string);
1498 rc = strlen(curr_event->string);
1499 goto out;
1500 }
1501
1502 /* number of arguments used for sprintf (without the format string) */
1503 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1504
1505 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1506
1507 for(i = 0; i < num_used_args; i++)
1508 index[i] = i;
1509
1510 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1511 curr_event->args[index[1]], curr_event->args[index[2]],
1512 curr_event->args[index[3]], curr_event->args[index[4]],
1513 curr_event->args[index[5]], curr_event->args[index[6]],
1514 curr_event->args[index[7]], curr_event->args[index[8]],
1515 curr_event->args[index[9]]);
1516
1517 out:
1518
1519 return rc;
1520 }
1521
1522 /*
1523 * clean up module
1524 */
1525 static void __exit debug_exit(void)
1526 {
1527 debugfs_remove(debug_debugfs_root_entry);
1528 unregister_sysctl_table(s390dbf_sysctl_header);
1529 return;
1530 }
1531
1532 /*
1533 * module definitions
1534 */
1535 postcore_initcall(debug_init);
1536 module_exit(debug_exit);
1537 MODULE_LICENSE("GPL");
1538
1539 EXPORT_SYMBOL(debug_register);
1540 EXPORT_SYMBOL(debug_unregister);
1541 EXPORT_SYMBOL(debug_set_level);
1542 EXPORT_SYMBOL(debug_stop_all);
1543 EXPORT_SYMBOL(debug_register_view);
1544 EXPORT_SYMBOL(debug_unregister_view);
1545 EXPORT_SYMBOL(debug_event_common);
1546 EXPORT_SYMBOL(debug_exception_common);
1547 EXPORT_SYMBOL(debug_hex_ascii_view);
1548 EXPORT_SYMBOL(debug_raw_view);
1549 EXPORT_SYMBOL(debug_dflt_header_fn);
1550 EXPORT_SYMBOL(debug_sprintf_view);
1551 EXPORT_SYMBOL(debug_sprintf_exception);
1552 EXPORT_SYMBOL(debug_sprintf_event);
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