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nfsd: don't fail unchecked creates of non-special files
[zen-stable.git] / arch / s390 / kernel / debug.c
blob6848828b962ea083b268b345992228e8dd13ccb4
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
38 typedef 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
54 typedef 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
69 static int debug_init(void);
70 static ssize_t debug_output(struct file *file, char __user *user_buf,
71 size_t user_len, loff_t * offset);
72 static ssize_t debug_input(struct file *file, const char __user *user_buf,
73 size_t user_len, loff_t * offset);
74 static int debug_open(struct inode *inode, struct file *file);
75 static int debug_close(struct inode *inode, struct file *file);
76 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
77 int nr_areas, int buf_size, umode_t mode);
78 static void debug_info_get(debug_info_t *);
79 static void debug_info_put(debug_info_t *);
80 static int debug_prolog_level_fn(debug_info_t * id,
81 struct debug_view *view, char *out_buf);
82 static 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);
85 static int debug_prolog_pages_fn(debug_info_t * id,
86 struct debug_view *view, char *out_buf);
87 static 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);
90 static 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);
93 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
94 char *out_buf, const char *in_buf);
95 static int debug_raw_format_fn(debug_info_t * id,
96 struct debug_view *view, char *out_buf,
97 const char *in_buf);
98 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
99 int area, debug_entry_t * entry, char *out_buf);
100
101 static 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
106 struct 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
115 struct 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
124 static 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
133 static 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
142 static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149 };
150
151 struct 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 */
161 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
162
163 /* static globals */
164
165 static debug_info_t *debug_area_first = NULL;
166 static debug_info_t *debug_area_last = NULL;
167 static DEFINE_MUTEX(debug_mutex);
168
169 static int initialized;
170
171 static 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
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, umode_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 nonseekable_open(inode, file);
660 out:
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
671 static int
672 debug_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
690 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
691 int nr_areas, int buf_size, umode_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);
712 out:
713 if (!rc){
714 pr_err("Registering debug feature %s failed\n", name);
715 }
716 mutex_unlock(&debug_mutex);
717 return rc;
718 }
719 EXPORT_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
727 debug_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
739 void
740 debug_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
748 out:
749 return;
750 }
751
752 /*
753 * debug_set_size:
754 * - set area size (number of pages) and number of areas
755 */
756 static int
757 debug_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);
786 out:
787 return rc;
788 }
789
790 /*
791 * debug_set_level:
792 * - set actual debug level
793 */
794
795 void
796 debug_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
820 static inline void
821 proceed_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
837 static inline void
838 proceed_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
848 static inline debug_entry_t*
849 get_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
861 static inline void
862 debug_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
875 static int debug_stoppable=1;
876 static 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 */
886 static int
887 s390dbf_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
897 static 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
915 static 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
925 static struct ctl_table_header *s390dbf_sysctl_header;
926
927 void
928 debug_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
940 debug_entry_t*
941 debug_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
963 debug_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
985 static inline int
986 debug_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
1001 debug_entry_t*
1002 debug_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
1034 debug_entry_t*
1035 debug_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
1069 static 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
1087 int
1088 debug_register_view(debug_info_t * id, struct debug_view *view)
1089 {
1090 int rc = 0;
1091 int i;
1092 unsigned long flags;
1093 umode_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);
1126 out:
1127 return rc;
1128 }
1129
1130 /*
1131 * debug_unregister_view:
1132 */
1133
1134 int
1135 debug_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);
1155 out:
1156 return rc;
1157 }
1158
1159 static inline char *
1160 debug_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
1179 static inline int
1180 debug_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
1201 static int
1202 debug_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
1212 static int
1213 debug_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;
1242 free_str:
1243 kfree(str);
1244 out:
1245 *offset += user_len;
1246 return rc; /* number of input characters */
1247 }
1248
1249 /*
1250 * prints out actual debug level
1251 */
1252
1253 static int
1254 debug_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
1271 static int
1272 debug_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 }
1305 free_str:
1306 kfree(str);
1307 out:
1308 *offset += user_len;
1309 return rc; /* number of input characters */
1310 }
1311
1312
1313 /*
1314 * flushes debug areas
1315 */
1316
1317 static 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
1348 static int
1349 debug_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
1379 out:
1380 *offset += user_len;
1381 return rc; /* number of input characters */
1382 }
1383
1384 /*
1385 * prints debug header in raw format
1386 */
1387
1388 static int
1389 debug_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
1403 static int
1404 debug_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
1418 static int
1419 debug_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
1444 int
1445 debug_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
1475 static int
1476 debug_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
1509 out:
1510
1511 return rc;
1512 }
1513
1514 /*
1515 * clean up module
1516 */
1517 static 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 */
1527 postcore_initcall(debug_init);
1528 module_exit(debug_exit);
1529 MODULE_LICENSE("GPL");
1530
1531 EXPORT_SYMBOL(debug_register);
1532 EXPORT_SYMBOL(debug_unregister);
1533 EXPORT_SYMBOL(debug_set_level);
1534 EXPORT_SYMBOL(debug_stop_all);
1535 EXPORT_SYMBOL(debug_register_view);
1536 EXPORT_SYMBOL(debug_unregister_view);
1537 EXPORT_SYMBOL(debug_event_common);
1538 EXPORT_SYMBOL(debug_exception_common);
1539 EXPORT_SYMBOL(debug_hex_ascii_view);
1540 EXPORT_SYMBOL(debug_raw_view);
1541 EXPORT_SYMBOL(debug_dflt_header_fn);
1542 EXPORT_SYMBOL(debug_sprintf_view);
1543 EXPORT_SYMBOL(debug_sprintf_exception);
1544 EXPORT_SYMBOL(debug_sprintf_event);