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sysctl frv: Remove dead binary sysctl support
[deliverable/linux.git] / arch / s390 / kernel / debug.c
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CommitLineData
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
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, mode_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};
113
114struct debug_view debug_hex_ascii_view = {
115 "hex_ascii",
116 NULL,
117 &debug_dflt_header_fn,
118 &debug_hex_ascii_format_fn,
119 NULL,
120 NULL
121};
122
123static struct debug_view debug_level_view = {
124 "level",
125 &debug_prolog_level_fn,
126 NULL,
127 NULL,
128 &debug_input_level_fn,
129 NULL
130};
131
132static struct debug_view debug_pages_view = {
133 "pages",
134 &debug_prolog_pages_fn,
135 NULL,
136 NULL,
137 &debug_input_pages_fn,
138 NULL
139};
140
141static struct debug_view debug_flush_view = {
142 "flush",
143 NULL,
144 NULL,
145 NULL,
146 &debug_input_flush_fn,
147 NULL
148};
149
150struct debug_view debug_sprintf_view = {
151 "sprintf",
152 NULL,
153 &debug_dflt_header_fn,
154 (debug_format_proc_t*)&debug_sprintf_format_fn,
155 NULL,
156 NULL
157};
158
159/* used by dump analysis tools to determine version of debug feature */
160static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
161
162/* static globals */
163
164static debug_info_t *debug_area_first = NULL;
165static debug_info_t *debug_area_last = NULL;
166static DEFINE_MUTEX(debug_mutex);
167
168static int initialized;
169
170static const struct file_operations debug_file_ops = {
171 .owner = THIS_MODULE,
172 .read = debug_output,
173 .write = debug_input,
174 .open = debug_open,
175 .release = debug_close,
176};
177
178static struct dentry *debug_debugfs_root_entry;
179
180/* functions */
181
182/*
183 * debug_areas_alloc
184 * - Debug areas are implemented as a threedimensonal array:
185 * areas[areanumber][pagenumber][pageoffset]
186 */
187
188static debug_entry_t***
189debug_areas_alloc(int pages_per_area, int nr_areas)
190{
191 debug_entry_t*** areas;
192 int i,j;
193
194 areas = kmalloc(nr_areas *
195 sizeof(debug_entry_t**),
196 GFP_KERNEL);
197 if (!areas)
198 goto fail_malloc_areas;
199 for (i = 0; i < nr_areas; i++) {
200 areas[i] = kmalloc(pages_per_area *
201 sizeof(debug_entry_t*),GFP_KERNEL);
202 if (!areas[i]) {
203 goto fail_malloc_areas2;
204 }
205 for(j = 0; j < pages_per_area; j++) {
206 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
207 if(!areas[i][j]) {
208 for(j--; j >=0 ; j--) {
209 kfree(areas[i][j]);
210 }
211 kfree(areas[i]);
212 goto fail_malloc_areas2;
213 }
214 }
215 }
216 return areas;
217
218fail_malloc_areas2:
219 for(i--; i >= 0; i--){
220 for(j=0; j < pages_per_area;j++){
221 kfree(areas[i][j]);
222 }
223 kfree(areas[i]);
224 }
225 kfree(areas);
226fail_malloc_areas:
227 return NULL;
228
229}
230
231
232/*
233 * debug_info_alloc
234 * - alloc new debug-info
235 */
236
237static debug_info_t*
238debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
239 int buf_size, int level, int mode)
240{
241 debug_info_t* rc;
242
243 /* alloc everything */
244
245 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
246 if(!rc)
247 goto fail_malloc_rc;
248 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
249 if(!rc->active_entries)
250 goto fail_malloc_active_entries;
251 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
252 if(!rc->active_pages)
253 goto fail_malloc_active_pages;
254 if((mode == ALL_AREAS) && (pages_per_area != 0)){
255 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
256 if(!rc->areas)
257 goto fail_malloc_areas;
258 } else {
259 rc->areas = NULL;
260 }
261
262 /* initialize members */
263
264 spin_lock_init(&rc->lock);
265 rc->pages_per_area = pages_per_area;
266 rc->nr_areas = nr_areas;
267 rc->active_area = 0;
268 rc->level = level;
269 rc->buf_size = buf_size;
270 rc->entry_size = sizeof(debug_entry_t) + buf_size;
271 strlcpy(rc->name, name, sizeof(rc->name));
272 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
273 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
274 sizeof(struct dentry*));
275 atomic_set(&(rc->ref_count), 0);
276
277 return rc;
278
279fail_malloc_areas:
280 kfree(rc->active_pages);
281fail_malloc_active_pages:
282 kfree(rc->active_entries);
283fail_malloc_active_entries:
284 kfree(rc);
285fail_malloc_rc:
286 return NULL;
287}
288
289/*
290 * debug_areas_free
291 * - free all debug areas
292 */
293
294static void
295debug_areas_free(debug_info_t* db_info)
296{
297 int i,j;
298
299 if(!db_info->areas)
300 return;
301 for (i = 0; i < db_info->nr_areas; i++) {
302 for(j = 0; j < db_info->pages_per_area; j++) {
303 kfree(db_info->areas[i][j]);
304 }
305 kfree(db_info->areas[i]);
306 }
307 kfree(db_info->areas);
308 db_info->areas = NULL;
309}
310
311/*
312 * debug_info_free
313 * - free memory debug-info
314 */
315
316static void
317debug_info_free(debug_info_t* db_info){
318 debug_areas_free(db_info);
319 kfree(db_info->active_entries);
320 kfree(db_info->active_pages);
321 kfree(db_info);
322}
323
324/*
325 * debug_info_create
326 * - create new debug-info
327 */
328
329static debug_info_t*
330debug_info_create(const char *name, int pages_per_area, int nr_areas,
331 int buf_size, mode_t mode)
332{
333 debug_info_t* rc;
334
335 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
336 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
337 if(!rc)
338 goto out;
339
340 rc->mode = mode & ~S_IFMT;
341
342 /* create root directory */
343 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
344 debug_debugfs_root_entry);
345
346 /* append new element to linked list */
347 if (!debug_area_first) {
348 /* first element in list */
349 debug_area_first = rc;
350 rc->prev = NULL;
351 } else {
352 /* append element to end of list */
353 debug_area_last->next = rc;
354 rc->prev = debug_area_last;
355 }
356 debug_area_last = rc;
357 rc->next = NULL;
358
359 debug_info_get(rc);
360out:
361 return rc;
362}
363
364/*
365 * debug_info_copy
366 * - copy debug-info
367 */
368
369static debug_info_t*
370debug_info_copy(debug_info_t* in, int mode)
371{
372 int i,j;
373 debug_info_t* rc;
374 unsigned long flags;
375
376 /* get a consistent copy of the debug areas */
377 do {
378 rc = debug_info_alloc(in->name, in->pages_per_area,
379 in->nr_areas, in->buf_size, in->level, mode);
380 spin_lock_irqsave(&in->lock, flags);
381 if(!rc)
382 goto out;
383 /* has something changed in the meantime ? */
384 if((rc->pages_per_area == in->pages_per_area) &&
385 (rc->nr_areas == in->nr_areas)) {
386 break;
387 }
388 spin_unlock_irqrestore(&in->lock, flags);
389 debug_info_free(rc);
390 } while (1);
391
392 if (mode == NO_AREAS)
393 goto out;
394
395 for(i = 0; i < in->nr_areas; i++){
396 for(j = 0; j < in->pages_per_area; j++) {
397 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
398 }
399 }
400out:
401 spin_unlock_irqrestore(&in->lock, flags);
402 return rc;
403}
404
405/*
406 * debug_info_get
407 * - increments reference count for debug-info
408 */
409
410static void
411debug_info_get(debug_info_t * db_info)
412{
413 if (db_info)
414 atomic_inc(&db_info->ref_count);
415}
416
417/*
418 * debug_info_put:
419 * - decreases reference count for debug-info and frees it if necessary
420 */
421
422static void
423debug_info_put(debug_info_t *db_info)
424{
425 int i;
426
427 if (!db_info)
428 return;
429 if (atomic_dec_and_test(&db_info->ref_count)) {
430 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
431 if (!db_info->views[i])
432 continue;
433 debugfs_remove(db_info->debugfs_entries[i]);
434 }
435 debugfs_remove(db_info->debugfs_root_entry);
436 if(db_info == debug_area_first)
437 debug_area_first = db_info->next;
438 if(db_info == debug_area_last)
439 debug_area_last = db_info->prev;
440 if(db_info->prev) db_info->prev->next = db_info->next;
441 if(db_info->next) db_info->next->prev = db_info->prev;
442 debug_info_free(db_info);
443 }
444}
445
446/*
447 * debug_format_entry:
448 * - format one debug entry and return size of formated data
449 */
450
451static int
452debug_format_entry(file_private_info_t *p_info)
453{
454 debug_info_t *id_snap = p_info->debug_info_snap;
455 struct debug_view *view = p_info->view;
456 debug_entry_t *act_entry;
457 size_t len = 0;
458 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
459 /* print prolog */
460 if (view->prolog_proc)
461 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
462 goto out;
463 }
464 if (!id_snap->areas) /* this is true, if we have a prolog only view */
465 goto out; /* or if 'pages_per_area' is 0 */
466 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
467 [p_info->act_page] + p_info->act_entry);
468
469 if (act_entry->id.stck == 0LL)
470 goto out; /* empty entry */
471 if (view->header_proc)
472 len += view->header_proc(id_snap, view, p_info->act_area,
473 act_entry, p_info->temp_buf + len);
474 if (view->format_proc)
475 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
476 DEBUG_DATA(act_entry));
477out:
478 return len;
479}
480
481/*
482 * debug_next_entry:
483 * - goto next entry in p_info
484 */
485
486static inline int
487debug_next_entry(file_private_info_t *p_info)
488{
489 debug_info_t *id;
490
491 id = p_info->debug_info_snap;
492 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
493 p_info->act_entry = 0;
494 p_info->act_page = 0;
495 goto out;
496 }
497 if(!id->areas)
498 return 1;
499 p_info->act_entry += id->entry_size;
500 /* switch to next page, if we reached the end of the page */
501 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
502 /* next page */
503 p_info->act_entry = 0;
504 p_info->act_page += 1;
505 if((p_info->act_page % id->pages_per_area) == 0) {
506 /* next area */
507 p_info->act_area++;
508 p_info->act_page=0;
509 }
510 if(p_info->act_area >= id->nr_areas)
511 return 1;
512 }
513out:
514 return 0;
515}
516
517/*
518 * debug_output:
519 * - called for user read()
520 * - copies formated debug entries to the user buffer
521 */
522
523static ssize_t
524debug_output(struct file *file, /* file descriptor */
525 char __user *user_buf, /* user buffer */
526 size_t len, /* length of buffer */
527 loff_t *offset) /* offset in the file */
528{
529 size_t count = 0;
530 size_t entry_offset;
531 file_private_info_t *p_info;
532
533 p_info = ((file_private_info_t *) file->private_data);
534 if (*offset != p_info->offset)
535 return -EPIPE;
536 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
537 return 0;
538 entry_offset = p_info->act_entry_offset;
539 while(count < len){
540 int formatted_line_size;
541 int formatted_line_residue;
542 int user_buf_residue;
543 size_t copy_size;
544
545 formatted_line_size = debug_format_entry(p_info);
546 formatted_line_residue = formatted_line_size - entry_offset;
547 user_buf_residue = len-count;
548 copy_size = min(user_buf_residue, formatted_line_residue);
549 if(copy_size){
550 if (copy_to_user(user_buf + count, p_info->temp_buf
551 + entry_offset, copy_size))
552 return -EFAULT;
553 count += copy_size;
554 entry_offset += copy_size;
555 }
556 if(copy_size == formatted_line_residue){
557 entry_offset = 0;
558 if(debug_next_entry(p_info))
559 goto out;
560 }
561 }
562out:
563 p_info->offset = *offset + count;
564 p_info->act_entry_offset = entry_offset;
565 *offset = p_info->offset;
566 return count;
567}
568
569/*
570 * debug_input:
571 * - called for user write()
572 * - calls input function of view
573 */
574
575static ssize_t
576debug_input(struct file *file, const char __user *user_buf, size_t length,
577 loff_t *offset)
578{
579 int rc = 0;
580 file_private_info_t *p_info;
581
582 mutex_lock(&debug_mutex);
583 p_info = ((file_private_info_t *) file->private_data);
584 if (p_info->view->input_proc)
585 rc = p_info->view->input_proc(p_info->debug_info_org,
586 p_info->view, file, user_buf,
587 length, offset);
588 else
589 rc = -EPERM;
590 mutex_unlock(&debug_mutex);
591 return rc; /* number of input characters */
592}
593
594/*
595 * debug_open:
596 * - called for user open()
597 * - copies formated output to private_data area of the file
598 * handle
599 */
600
601static int
602debug_open(struct inode *inode, struct file *file)
603{
604 int i, rc = 0;
605 file_private_info_t *p_info;
606 debug_info_t *debug_info, *debug_info_snapshot;
607
608 mutex_lock(&debug_mutex);
609 debug_info = file->f_path.dentry->d_inode->i_private;
610 /* find debug view */
611 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
612 if (!debug_info->views[i])
613 continue;
614 else if (debug_info->debugfs_entries[i] ==
615 file->f_path.dentry) {
616 goto found; /* found view ! */
617 }
618 }
619 /* no entry found */
620 rc = -EINVAL;
621 goto out;
622
623found:
624
625 /* Make snapshot of current debug areas to get it consistent. */
626 /* To copy all the areas is only needed, if we have a view which */
627 /* formats the debug areas. */
628
629 if(!debug_info->views[i]->format_proc &&
630 !debug_info->views[i]->header_proc){
631 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
632 } else {
633 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
634 }
635
636 if(!debug_info_snapshot){
637 rc = -ENOMEM;
638 goto out;
639 }
640 p_info = kmalloc(sizeof(file_private_info_t),
641 GFP_KERNEL);
642 if(!p_info){
643 debug_info_free(debug_info_snapshot);
644 rc = -ENOMEM;
645 goto out;
646 }
647 p_info->offset = 0;
648 p_info->debug_info_snap = debug_info_snapshot;
649 p_info->debug_info_org = debug_info;
650 p_info->view = debug_info->views[i];
651 p_info->act_area = 0;
652 p_info->act_page = 0;
653 p_info->act_entry = DEBUG_PROLOG_ENTRY;
654 p_info->act_entry_offset = 0;
655 file->private_data = p_info;
656 debug_info_get(debug_info);
657out:
658 mutex_unlock(&debug_mutex);
659 return rc;
660}
661
662/*
663 * debug_close:
664 * - called for user close()
665 * - deletes private_data area of the file handle
666 */
667
668static int
669debug_close(struct inode *inode, struct file *file)
670{
671 file_private_info_t *p_info;
672 p_info = (file_private_info_t *) file->private_data;
673 if(p_info->debug_info_snap)
674 debug_info_free(p_info->debug_info_snap);
675 debug_info_put(p_info->debug_info_org);
676 kfree(file->private_data);
677 return 0; /* success */
678}
679
680/*
681 * debug_register_mode:
682 * - Creates and initializes debug area for the caller
683 * The mode parameter allows to specify access rights for the s390dbf files
684 * - Returns handle for debug area
685 */
686
687debug_info_t *debug_register_mode(const char *name, int pages_per_area,
688 int nr_areas, int buf_size, mode_t mode,
689 uid_t uid, gid_t gid)
690{
691 debug_info_t *rc = NULL;
692
693 /* Since debugfs currently does not support uid/gid other than root, */
694 /* we do not allow gid/uid != 0 until we get support for that. */
695 if ((uid != 0) || (gid != 0))
696 pr_warning("Root becomes the owner of all s390dbf files "
697 "in sysfs\n");
698 BUG_ON(!initialized);
699 mutex_lock(&debug_mutex);
700
701 /* create new debug_info */
702
703 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
704 if(!rc)
705 goto out;
706 debug_register_view(rc, &debug_level_view);
707 debug_register_view(rc, &debug_flush_view);
708 debug_register_view(rc, &debug_pages_view);
709out:
710 if (!rc){
711 pr_err("Registering debug feature %s failed\n", name);
712 }
713 mutex_unlock(&debug_mutex);
714 return rc;
715}
716EXPORT_SYMBOL(debug_register_mode);
717
718/*
719 * debug_register:
720 * - creates and initializes debug area for the caller
721 * - returns handle for debug area
722 */
723
724debug_info_t *debug_register(const char *name, int pages_per_area,
725 int nr_areas, int buf_size)
726{
727 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
728 S_IRUSR | S_IWUSR, 0, 0);
729}
730
731/*
732 * debug_unregister:
733 * - give back debug area
734 */
735
736void
737debug_unregister(debug_info_t * id)
738{
739 if (!id)
740 goto out;
741 mutex_lock(&debug_mutex);
742 debug_info_put(id);
743 mutex_unlock(&debug_mutex);
744
745out:
746 return;
747}
748
749/*
750 * debug_set_size:
751 * - set area size (number of pages) and number of areas
752 */
753static int
754debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
755{
756 unsigned long flags;
757 debug_entry_t *** new_areas;
758 int rc=0;
759
760 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
761 return -EINVAL;
762 if(pages_per_area > 0){
763 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
764 if(!new_areas) {
765 pr_info("Allocating memory for %i pages failed\n",
766 pages_per_area);
767 rc = -ENOMEM;
768 goto out;
769 }
770 } else {
771 new_areas = NULL;
772 }
773 spin_lock_irqsave(&id->lock,flags);
774 debug_areas_free(id);
775 id->areas = new_areas;
776 id->nr_areas = nr_areas;
777 id->pages_per_area = pages_per_area;
778 id->active_area = 0;
779 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
780 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
781 spin_unlock_irqrestore(&id->lock,flags);
782 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
783out:
784 return rc;
785}
786
787/*
788 * debug_set_level:
789 * - set actual debug level
790 */
791
792void
793debug_set_level(debug_info_t* id, int new_level)
794{
795 unsigned long flags;
796 if(!id)
797 return;
798 spin_lock_irqsave(&id->lock,flags);
799 if(new_level == DEBUG_OFF_LEVEL){
800 id->level = DEBUG_OFF_LEVEL;
801 pr_info("%s: switched off\n",id->name);
802 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
803 pr_info("%s: level %i is out of range (%i - %i)\n",
804 id->name, new_level, 0, DEBUG_MAX_LEVEL);
805 } else {
806 id->level = new_level;
807 }
808 spin_unlock_irqrestore(&id->lock,flags);
809}
810
811
812/*
813 * proceed_active_entry:
814 * - set active entry to next in the ring buffer
815 */
816
817static inline void
818proceed_active_entry(debug_info_t * id)
819{
820 if ((id->active_entries[id->active_area] += id->entry_size)
821 > (PAGE_SIZE - id->entry_size)){
822 id->active_entries[id->active_area] = 0;
823 id->active_pages[id->active_area] =
824 (id->active_pages[id->active_area] + 1) %
825 id->pages_per_area;
826 }
827}
828
829/*
830 * proceed_active_area:
831 * - set active area to next in the ring buffer
832 */
833
834static inline void
835proceed_active_area(debug_info_t * id)
836{
837 id->active_area++;
838 id->active_area = id->active_area % id->nr_areas;
839}
840
841/*
842 * get_active_entry:
843 */
844
845static inline debug_entry_t*
846get_active_entry(debug_info_t * id)
847{
848 return (debug_entry_t *) (((char *) id->areas[id->active_area]
849 [id->active_pages[id->active_area]]) +
850 id->active_entries[id->active_area]);
851}
852
853/*
854 * debug_finish_entry:
855 * - set timestamp, caller address, cpu number etc.
856 */
857
858static inline void
859debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
860 int exception)
861{
862 active->id.stck = get_clock();
863 active->id.fields.cpuid = smp_processor_id();
864 active->caller = __builtin_return_address(0);
865 active->id.fields.exception = exception;
866 active->id.fields.level = level;
867 proceed_active_entry(id);
868 if(exception)
869 proceed_active_area(id);
870}
871
872static int debug_stoppable=1;
873static int debug_active=1;
874
875#define CTL_S390DBF_STOPPABLE 5678
876#define CTL_S390DBF_ACTIVE 5679
877
878/*
879 * proc handler for the running debug_active sysctl
880 * always allow read, allow write only if debug_stoppable is set or
881 * if debug_active is already off
882 */
883static int
884s390dbf_procactive(ctl_table *table, int write,
885 void __user *buffer, size_t *lenp, loff_t *ppos)
886{
887 if (!write || debug_stoppable || !debug_active)
888 return proc_dointvec(table, write, buffer, lenp, ppos);
889 else
890 return 0;
891}
892
893
894static struct ctl_table s390dbf_table[] = {
895 {
896 .ctl_name = CTL_S390DBF_STOPPABLE,
897 .procname = "debug_stoppable",
898 .data = &debug_stoppable,
899 .maxlen = sizeof(int),
900 .mode = S_IRUGO | S_IWUSR,
901 .proc_handler = &proc_dointvec,
902 .strategy = &sysctl_intvec,
903 },
904 {
905 .ctl_name = CTL_S390DBF_ACTIVE,
906 .procname = "debug_active",
907 .data = &debug_active,
908 .maxlen = sizeof(int),
909 .mode = S_IRUGO | S_IWUSR,
910 .proc_handler = &s390dbf_procactive,
911 .strategy = &sysctl_intvec,
912 },
913 { .ctl_name = 0 }
914};
915
916static struct ctl_table s390dbf_dir_table[] = {
917 {
918 .ctl_name = CTL_S390DBF,
919 .procname = "s390dbf",
920 .maxlen = 0,
921 .mode = S_IRUGO | S_IXUGO,
922 .child = s390dbf_table,
923 },
924 { .ctl_name = 0 }
925};
926
927static struct ctl_table_header *s390dbf_sysctl_header;
928
929void
930debug_stop_all(void)
931{
932 if (debug_stoppable)
933 debug_active = 0;
934}
935
936
937/*
938 * debug_event_common:
939 * - write debug entry with given size
940 */
941
942debug_entry_t*
943debug_event_common(debug_info_t * id, int level, const void *buf, int len)
944{
945 unsigned long flags;
946 debug_entry_t *active;
947
948 if (!debug_active || !id->areas)
949 return NULL;
950 spin_lock_irqsave(&id->lock, flags);
951 active = get_active_entry(id);
952 memset(DEBUG_DATA(active), 0, id->buf_size);
953 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
954 debug_finish_entry(id, active, level, 0);
955 spin_unlock_irqrestore(&id->lock, flags);
956
957 return active;
958}
959
960/*
961 * debug_exception_common:
962 * - write debug entry with given size and switch to next debug area
963 */
964
965debug_entry_t
966*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
967{
968 unsigned long flags;
969 debug_entry_t *active;
970
971 if (!debug_active || !id->areas)
972 return NULL;
973 spin_lock_irqsave(&id->lock, flags);
974 active = get_active_entry(id);
975 memset(DEBUG_DATA(active), 0, id->buf_size);
976 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
977 debug_finish_entry(id, active, level, 1);
978 spin_unlock_irqrestore(&id->lock, flags);
979
980 return active;
981}
982
983/*
984 * counts arguments in format string for sprintf view
985 */
986
987static inline int
988debug_count_numargs(char *string)
989{
990 int numargs=0;
991
992 while(*string) {
993 if(*string++=='%')
994 numargs++;
995 }
996 return(numargs);
997}
998
999/*
1000 * debug_sprintf_event:
1001 */
1002
1003debug_entry_t*
1004debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1005{
1006 va_list ap;
1007 int numargs,idx;
1008 unsigned long flags;
1009 debug_sprintf_entry_t *curr_event;
1010 debug_entry_t *active;
1011
1012 if((!id) || (level > id->level))
1013 return NULL;
1014 if (!debug_active || !id->areas)
1015 return NULL;
1016 numargs=debug_count_numargs(string);
1017
1018 spin_lock_irqsave(&id->lock, flags);
1019 active = get_active_entry(id);
1020 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1021 va_start(ap,string);
1022 curr_event->string=string;
1023 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1024 curr_event->args[idx]=va_arg(ap,long);
1025 va_end(ap);
1026 debug_finish_entry(id, active, level, 0);
1027 spin_unlock_irqrestore(&id->lock, flags);
1028
1029 return active;
1030}
1031
1032/*
1033 * debug_sprintf_exception:
1034 */
1035
1036debug_entry_t*
1037debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1038{
1039 va_list ap;
1040 int numargs,idx;
1041 unsigned long flags;
1042 debug_sprintf_entry_t *curr_event;
1043 debug_entry_t *active;
1044
1045 if((!id) || (level > id->level))
1046 return NULL;
1047 if (!debug_active || !id->areas)
1048 return NULL;
1049
1050 numargs=debug_count_numargs(string);
1051
1052 spin_lock_irqsave(&id->lock, flags);
1053 active = get_active_entry(id);
1054 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1055 va_start(ap,string);
1056 curr_event->string=string;
1057 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1058 curr_event->args[idx]=va_arg(ap,long);
1059 va_end(ap);
1060 debug_finish_entry(id, active, level, 1);
1061 spin_unlock_irqrestore(&id->lock, flags);
1062
1063 return active;
1064}
1065
1066/*
1067 * debug_init:
1068 * - is called exactly once to initialize the debug feature
1069 */
1070
1071static int
1072__init debug_init(void)
1073{
1074 int rc = 0;
1075
1076 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1077 mutex_lock(&debug_mutex);
1078 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1079 initialized = 1;
1080 mutex_unlock(&debug_mutex);
1081
1082 return rc;
1083}
1084
1085/*
1086 * debug_register_view:
1087 */
1088
1089int
1090debug_register_view(debug_info_t * id, struct debug_view *view)
1091{
1092 int rc = 0;
1093 int i;
1094 unsigned long flags;
1095 mode_t mode;
1096 struct dentry *pde;
1097
1098 if (!id)
1099 goto out;
1100 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1101 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1102 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1103 if (!view->input_proc)
1104 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1105 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1106 id , &debug_file_ops);
1107 if (!pde){
1108 pr_err("Registering view %s/%s failed due to out of "
1109 "memory\n", id->name,view->name);
1110 rc = -1;
1111 goto out;
1112 }
1113 spin_lock_irqsave(&id->lock, flags);
1114 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1115 if (!id->views[i])
1116 break;
1117 }
1118 if (i == DEBUG_MAX_VIEWS) {
1119 pr_err("Registering view %s/%s would exceed the maximum "
1120 "number of views %i\n", id->name, view->name, i);
1121 debugfs_remove(pde);
1122 rc = -1;
1123 } else {
1124 id->views[i] = view;
1125 id->debugfs_entries[i] = pde;
1126 }
1127 spin_unlock_irqrestore(&id->lock, flags);
1128out:
1129 return rc;
1130}
1131
1132/*
1133 * debug_unregister_view:
1134 */
1135
1136int
1137debug_unregister_view(debug_info_t * id, struct debug_view *view)
1138{
1139 int rc = 0;
1140 int i;
1141 unsigned long flags;
1142
1143 if (!id)
1144 goto out;
1145 spin_lock_irqsave(&id->lock, flags);
1146 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1147 if (id->views[i] == view)
1148 break;
1149 }
1150 if (i == DEBUG_MAX_VIEWS)
1151 rc = -1;
1152 else {
1153 debugfs_remove(id->debugfs_entries[i]);
1154 id->views[i] = NULL;
1155 }
1156 spin_unlock_irqrestore(&id->lock, flags);
1157out:
1158 return rc;
1159}
1160
1161static inline char *
1162debug_get_user_string(const char __user *user_buf, size_t user_len)
1163{
1164 char* buffer;
1165
1166 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1167 if (!buffer)
1168 return ERR_PTR(-ENOMEM);
1169 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1170 kfree(buffer);
1171 return ERR_PTR(-EFAULT);
1172 }
1173 /* got the string, now strip linefeed. */
1174 if (buffer[user_len - 1] == '\n')
1175 buffer[user_len - 1] = 0;
1176 else
1177 buffer[user_len] = 0;
1178 return buffer;
1179}
1180
1181static inline int
1182debug_get_uint(char *buf)
1183{
1184 int rc;
1185
1186 for(; isspace(*buf); buf++);
1187 rc = simple_strtoul(buf, &buf, 10);
1188 if(*buf){
1189 rc = -EINVAL;
1190 }
1191 return rc;
1192}
1193
1194/*
1195 * functions for debug-views
1196 ***********************************
1197*/
1198
1199/*
1200 * prints out actual debug level
1201 */
1202
1203static int
1204debug_prolog_pages_fn(debug_info_t * id,
1205 struct debug_view *view, char *out_buf)
1206{
1207 return sprintf(out_buf, "%i\n", id->pages_per_area);
1208}
1209
1210/*
1211 * reads new size (number of pages per debug area)
1212 */
1213
1214static int
1215debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1216 struct file *file, const char __user *user_buf,
1217 size_t user_len, loff_t * offset)
1218{
1219 char *str;
1220 int rc,new_pages;
1221
1222 if (user_len > 0x10000)
1223 user_len = 0x10000;
1224 if (*offset != 0){
1225 rc = -EPIPE;
1226 goto out;
1227 }
1228 str = debug_get_user_string(user_buf,user_len);
1229 if(IS_ERR(str)){
1230 rc = PTR_ERR(str);
1231 goto out;
1232 }
1233 new_pages = debug_get_uint(str);
1234 if(new_pages < 0){
1235 rc = -EINVAL;
1236 goto free_str;
1237 }
1238 rc = debug_set_size(id,id->nr_areas, new_pages);
1239 if(rc != 0){
1240 rc = -EINVAL;
1241 goto free_str;
1242 }
1243 rc = user_len;
1244free_str:
1245 kfree(str);
1246out:
1247 *offset += user_len;
1248 return rc; /* number of input characters */
1249}
1250
1251/*
1252 * prints out actual debug level
1253 */
1254
1255static int
1256debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1257{
1258 int rc = 0;
1259
1260 if(id->level == DEBUG_OFF_LEVEL) {
1261 rc = sprintf(out_buf,"-\n");
1262 }
1263 else {
1264 rc = sprintf(out_buf, "%i\n", id->level);
1265 }
1266 return rc;
1267}
1268
1269/*
1270 * reads new debug level
1271 */
1272
1273static int
1274debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1275 struct file *file, const char __user *user_buf,
1276 size_t user_len, loff_t * offset)
1277{
1278 char *str;
1279 int rc,new_level;
1280
1281 if (user_len > 0x10000)
1282 user_len = 0x10000;
1283 if (*offset != 0){
1284 rc = -EPIPE;
1285 goto out;
1286 }
1287 str = debug_get_user_string(user_buf,user_len);
1288 if(IS_ERR(str)){
1289 rc = PTR_ERR(str);
1290 goto out;
1291 }
1292 if(str[0] == '-'){
1293 debug_set_level(id, DEBUG_OFF_LEVEL);
1294 rc = user_len;
1295 goto free_str;
1296 } else {
1297 new_level = debug_get_uint(str);
1298 }
1299 if(new_level < 0) {
1300 pr_warning("%s is not a valid level for a debug "
1301 "feature\n", str);
1302 rc = -EINVAL;
1303 } else {
1304 debug_set_level(id, new_level);
1305 rc = user_len;
1306 }
1307free_str:
1308 kfree(str);
1309out:
1310 *offset += user_len;
1311 return rc; /* number of input characters */
1312}
1313
1314
1315/*
1316 * flushes debug areas
1317 */
1318
1319static void debug_flush(debug_info_t* id, int area)
1320{
1321 unsigned long flags;
1322 int i,j;
1323
1324 if(!id || !id->areas)
1325 return;
1326 spin_lock_irqsave(&id->lock,flags);
1327 if(area == DEBUG_FLUSH_ALL){
1328 id->active_area = 0;
1329 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1330 for (i = 0; i < id->nr_areas; i++) {
1331 id->active_pages[i] = 0;
1332 for(j = 0; j < id->pages_per_area; j++) {
1333 memset(id->areas[i][j], 0, PAGE_SIZE);
1334 }
1335 }
1336 } else if(area >= 0 && area < id->nr_areas) {
1337 id->active_entries[area] = 0;
1338 id->active_pages[area] = 0;
1339 for(i = 0; i < id->pages_per_area; i++) {
1340 memset(id->areas[area][i],0,PAGE_SIZE);
1341 }
1342 }
1343 spin_unlock_irqrestore(&id->lock,flags);
1344}
1345
1346/*
1347 * view function: flushes debug areas
1348 */
1349
1350static int
1351debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1352 struct file *file, const char __user *user_buf,
1353 size_t user_len, loff_t * offset)
1354{
1355 char input_buf[1];
1356 int rc = user_len;
1357
1358 if (user_len > 0x10000)
1359 user_len = 0x10000;
1360 if (*offset != 0){
1361 rc = -EPIPE;
1362 goto out;
1363 }
1364 if (copy_from_user(input_buf, user_buf, 1)){
1365 rc = -EFAULT;
1366 goto out;
1367 }
1368 if(input_buf[0] == '-') {
1369 debug_flush(id, DEBUG_FLUSH_ALL);
1370 goto out;
1371 }
1372 if (isdigit(input_buf[0])) {
1373 int area = ((int) input_buf[0] - (int) '0');
1374 debug_flush(id, area);
1375 goto out;
1376 }
1377
1378 pr_info("Flushing debug data failed because %c is not a valid "
1379 "area\n", input_buf[0]);
1380
1381out:
1382 *offset += user_len;
1383 return rc; /* number of input characters */
1384}
1385
1386/*
1387 * prints debug header in raw format
1388 */
1389
1390static int
1391debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1392 int area, debug_entry_t * entry, char *out_buf)
1393{
1394 int rc;
1395
1396 rc = sizeof(debug_entry_t);
1397 memcpy(out_buf,entry,sizeof(debug_entry_t));
1398 return rc;
1399}
1400
1401/*
1402 * prints debug data in raw format
1403 */
1404
1405static int
1406debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1407 char *out_buf, const char *in_buf)
1408{
1409 int rc;
1410
1411 rc = id->buf_size;
1412 memcpy(out_buf, in_buf, id->buf_size);
1413 return rc;
1414}
1415
1416/*
1417 * prints debug data in hex/ascii format
1418 */
1419
1420static int
1421debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1422 char *out_buf, const char *in_buf)
1423{
1424 int i, rc = 0;
1425
1426 for (i = 0; i < id->buf_size; i++) {
1427 rc += sprintf(out_buf + rc, "%02x ",
1428 ((unsigned char *) in_buf)[i]);
1429 }
1430 rc += sprintf(out_buf + rc, "| ");
1431 for (i = 0; i < id->buf_size; i++) {
1432 unsigned char c = in_buf[i];
1433 if (!isprint(c))
1434 rc += sprintf(out_buf + rc, ".");
1435 else
1436 rc += sprintf(out_buf + rc, "%c", c);
1437 }
1438 rc += sprintf(out_buf + rc, "\n");
1439 return rc;
1440}
1441
1442/*
1443 * prints header for debug entry
1444 */
1445
1446int
1447debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1448 int area, debug_entry_t * entry, char *out_buf)
1449{
1450 struct timespec time_spec;
1451 char *except_str;
1452 unsigned long caller;
1453 int rc = 0;
1454 unsigned int level;
1455
1456 level = entry->id.fields.level;
1457 stck_to_timespec(entry->id.stck, &time_spec);
1458
1459 if (entry->id.fields.exception)
1460 except_str = "*";
1461 else
1462 except_str = "-";
1463 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1464 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1465 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1466 except_str, entry->id.fields.cpuid, (void *) caller);
1467 return rc;
1468}
1469
1470/*
1471 * prints debug data sprintf-formated:
1472 * debug_sprinf_event/exception calls must be used together with this view
1473 */
1474
1475#define DEBUG_SPRINTF_MAX_ARGS 10
1476
1477static int
1478debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1479 char *out_buf, debug_sprintf_entry_t *curr_event)
1480{
1481 int num_longs, num_used_args = 0,i, rc = 0;
1482 int index[DEBUG_SPRINTF_MAX_ARGS];
1483
1484 /* count of longs fit into one entry */
1485 num_longs = id->buf_size / sizeof(long);
1486
1487 if(num_longs < 1)
1488 goto out; /* bufsize of entry too small */
1489 if(num_longs == 1) {
1490 /* no args, we use only the string */
1491 strcpy(out_buf, curr_event->string);
1492 rc = strlen(curr_event->string);
1493 goto out;
1494 }
1495
1496 /* number of arguments used for sprintf (without the format string) */
1497 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1498
1499 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1500
1501 for(i = 0; i < num_used_args; i++)
1502 index[i] = i;
1503
1504 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1505 curr_event->args[index[1]], curr_event->args[index[2]],
1506 curr_event->args[index[3]], curr_event->args[index[4]],
1507 curr_event->args[index[5]], curr_event->args[index[6]],
1508 curr_event->args[index[7]], curr_event->args[index[8]],
1509 curr_event->args[index[9]]);
1510
1511out:
1512
1513 return rc;
1514}
1515
1516/*
1517 * clean up module
1518 */
1519static void __exit debug_exit(void)
1520{
1521 debugfs_remove(debug_debugfs_root_entry);
1522 unregister_sysctl_table(s390dbf_sysctl_header);
1523 return;
1524}
1525
1526/*
1527 * module definitions
1528 */
1529postcore_initcall(debug_init);
1530module_exit(debug_exit);
1531MODULE_LICENSE("GPL");
1532
1533EXPORT_SYMBOL(debug_register);
1534EXPORT_SYMBOL(debug_unregister);
1535EXPORT_SYMBOL(debug_set_level);
1536EXPORT_SYMBOL(debug_stop_all);
1537EXPORT_SYMBOL(debug_register_view);
1538EXPORT_SYMBOL(debug_unregister_view);
1539EXPORT_SYMBOL(debug_event_common);
1540EXPORT_SYMBOL(debug_exception_common);
1541EXPORT_SYMBOL(debug_hex_ascii_view);
1542EXPORT_SYMBOL(debug_raw_view);
1543EXPORT_SYMBOL(debug_dflt_header_fn);
1544EXPORT_SYMBOL(debug_sprintf_view);
1545EXPORT_SYMBOL(debug_sprintf_exception);
1546EXPORT_SYMBOL(debug_sprintf_event);
Linux kernel - Deliverables
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