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dccp: do not assume DCCP code is non preemptible
[linux/fpc-iii.git] / arch / s390 / kernel / debug.c
blobaa12de72fd47c9d9d8c13f1c4a1734eababe3891
1 /*
2 * S/390 debug facility
3 *
4 * Copyright IBM Corp. 1999, 2012
5 *
6 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
7 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
8 *
9 * Bugreports to: <Linux390@de.ibm.com>
10 */
11
12 #define KMSG_COMPONENT "s390dbf"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14
15 #include <linux/stddef.h>
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/ctype.h>
20 #include <linux/string.h>
21 #include <linux/sysctl.h>
22 #include <asm/uaccess.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/fs.h>
26 #include <linux/debugfs.h>
27
28 #include <asm/debug.h>
29
30 #define DEBUG_PROLOG_ENTRY -1
31
32 #define ALL_AREAS 0 /* copy all debug areas */
33 #define NO_AREAS 1 /* copy no debug areas */
34
35 /* typedefs */
36
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 /* internal function prototyes */
67
68 static int debug_init(void);
69 static ssize_t debug_output(struct file *file, char __user *user_buf,
70 size_t user_len, loff_t * offset);
71 static ssize_t debug_input(struct file *file, const char __user *user_buf,
72 size_t user_len, loff_t * offset);
73 static int debug_open(struct inode *inode, struct file *file);
74 static int debug_close(struct inode *inode, struct file *file);
75 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76 int nr_areas, int buf_size, umode_t mode);
77 static void debug_info_get(debug_info_t *);
78 static void debug_info_put(debug_info_t *);
79 static int debug_prolog_level_fn(debug_info_t * id,
80 struct debug_view *view, char *out_buf);
81 static 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);
84 static int debug_prolog_pages_fn(debug_info_t * id,
85 struct debug_view *view, char *out_buf);
86 static 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);
89 static 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);
92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93 char *out_buf, const char *in_buf);
94 static int debug_raw_format_fn(debug_info_t * id,
95 struct debug_view *view, char *out_buf,
96 const char *in_buf);
97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98 int area, debug_entry_t * entry, char *out_buf);
99
100 static 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
105 struct 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 EXPORT_SYMBOL(debug_raw_view);
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 EXPORT_SYMBOL(debug_hex_ascii_view);
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 EXPORT_SYMBOL(debug_sprintf_view);
161
162 /* used by dump analysis tools to determine version of debug feature */
163 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
164
165 /* static globals */
166
167 static debug_info_t *debug_area_first = NULL;
168 static debug_info_t *debug_area_last = NULL;
169 static DEFINE_MUTEX(debug_mutex);
170
171 static int initialized;
172 static int debug_critical;
173
174 static const struct file_operations debug_file_ops = {
175 .owner = THIS_MODULE,
176 .read = debug_output,
177 .write = debug_input,
178 .open = debug_open,
179 .release = debug_close,
180 .llseek = no_llseek,
181 };
182
183 static struct dentry *debug_debugfs_root_entry;
184
185 /* functions */
186
187 /*
188 * debug_areas_alloc
189 * - Debug areas are implemented as a threedimensonal array:
190 * areas[areanumber][pagenumber][pageoffset]
191 */
192
193 static debug_entry_t***
194 debug_areas_alloc(int pages_per_area, int nr_areas)
195 {
196 debug_entry_t*** areas;
197 int i,j;
198
199 areas = kmalloc(nr_areas *
200 sizeof(debug_entry_t**),
201 GFP_KERNEL);
202 if (!areas)
203 goto fail_malloc_areas;
204 for (i = 0; i < nr_areas; i++) {
205 areas[i] = kmalloc(pages_per_area *
206 sizeof(debug_entry_t*),GFP_KERNEL);
207 if (!areas[i]) {
208 goto fail_malloc_areas2;
209 }
210 for(j = 0; j < pages_per_area; j++) {
211 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
212 if(!areas[i][j]) {
213 for(j--; j >=0 ; j--) {
214 kfree(areas[i][j]);
215 }
216 kfree(areas[i]);
217 goto fail_malloc_areas2;
218 }
219 }
220 }
221 return areas;
222
223 fail_malloc_areas2:
224 for(i--; i >= 0; i--){
225 for(j=0; j < pages_per_area;j++){
226 kfree(areas[i][j]);
227 }
228 kfree(areas[i]);
229 }
230 kfree(areas);
231 fail_malloc_areas:
232 return NULL;
233
234 }
235
236
237 /*
238 * debug_info_alloc
239 * - alloc new debug-info
240 */
241
242 static debug_info_t*
243 debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
244 int buf_size, int level, int mode)
245 {
246 debug_info_t* rc;
247
248 /* alloc everything */
249
250 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
251 if(!rc)
252 goto fail_malloc_rc;
253 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254 if(!rc->active_entries)
255 goto fail_malloc_active_entries;
256 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
257 if(!rc->active_pages)
258 goto fail_malloc_active_pages;
259 if((mode == ALL_AREAS) && (pages_per_area != 0)){
260 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
261 if(!rc->areas)
262 goto fail_malloc_areas;
263 } else {
264 rc->areas = NULL;
265 }
266
267 /* initialize members */
268
269 spin_lock_init(&rc->lock);
270 rc->pages_per_area = pages_per_area;
271 rc->nr_areas = nr_areas;
272 rc->active_area = 0;
273 rc->level = level;
274 rc->buf_size = buf_size;
275 rc->entry_size = sizeof(debug_entry_t) + buf_size;
276 strlcpy(rc->name, name, sizeof(rc->name));
277 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
278 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
279 sizeof(struct dentry*));
280 atomic_set(&(rc->ref_count), 0);
281
282 return rc;
283
284 fail_malloc_areas:
285 kfree(rc->active_pages);
286 fail_malloc_active_pages:
287 kfree(rc->active_entries);
288 fail_malloc_active_entries:
289 kfree(rc);
290 fail_malloc_rc:
291 return NULL;
292 }
293
294 /*
295 * debug_areas_free
296 * - free all debug areas
297 */
298
299 static void
300 debug_areas_free(debug_info_t* db_info)
301 {
302 int i,j;
303
304 if(!db_info->areas)
305 return;
306 for (i = 0; i < db_info->nr_areas; i++) {
307 for(j = 0; j < db_info->pages_per_area; j++) {
308 kfree(db_info->areas[i][j]);
309 }
310 kfree(db_info->areas[i]);
311 }
312 kfree(db_info->areas);
313 db_info->areas = NULL;
314 }
315
316 /*
317 * debug_info_free
318 * - free memory debug-info
319 */
320
321 static void
322 debug_info_free(debug_info_t* db_info){
323 debug_areas_free(db_info);
324 kfree(db_info->active_entries);
325 kfree(db_info->active_pages);
326 kfree(db_info);
327 }
328
329 /*
330 * debug_info_create
331 * - create new debug-info
332 */
333
334 static debug_info_t*
335 debug_info_create(const char *name, int pages_per_area, int nr_areas,
336 int buf_size, umode_t mode)
337 {
338 debug_info_t* rc;
339
340 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
341 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
342 if(!rc)
343 goto out;
344
345 rc->mode = mode & ~S_IFMT;
346
347 /* create root directory */
348 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
349 debug_debugfs_root_entry);
350
351 /* append new element to linked list */
352 if (!debug_area_first) {
353 /* first element in list */
354 debug_area_first = rc;
355 rc->prev = NULL;
356 } else {
357 /* append element to end of list */
358 debug_area_last->next = rc;
359 rc->prev = debug_area_last;
360 }
361 debug_area_last = rc;
362 rc->next = NULL;
363
364 debug_info_get(rc);
365 out:
366 return rc;
367 }
368
369 /*
370 * debug_info_copy
371 * - copy debug-info
372 */
373
374 static debug_info_t*
375 debug_info_copy(debug_info_t* in, int mode)
376 {
377 int i,j;
378 debug_info_t* rc;
379 unsigned long flags;
380
381 /* get a consistent copy of the debug areas */
382 do {
383 rc = debug_info_alloc(in->name, in->pages_per_area,
384 in->nr_areas, in->buf_size, in->level, mode);
385 spin_lock_irqsave(&in->lock, flags);
386 if(!rc)
387 goto out;
388 /* has something changed in the meantime ? */
389 if((rc->pages_per_area == in->pages_per_area) &&
390 (rc->nr_areas == in->nr_areas)) {
391 break;
392 }
393 spin_unlock_irqrestore(&in->lock, flags);
394 debug_info_free(rc);
395 } while (1);
396
397 if (mode == NO_AREAS)
398 goto out;
399
400 for(i = 0; i < in->nr_areas; i++){
401 for(j = 0; j < in->pages_per_area; j++) {
402 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
403 }
404 }
405 out:
406 spin_unlock_irqrestore(&in->lock, flags);
407 return rc;
408 }
409
410 /*
411 * debug_info_get
412 * - increments reference count for debug-info
413 */
414
415 static void
416 debug_info_get(debug_info_t * db_info)
417 {
418 if (db_info)
419 atomic_inc(&db_info->ref_count);
420 }
421
422 /*
423 * debug_info_put:
424 * - decreases reference count for debug-info and frees it if necessary
425 */
426
427 static void
428 debug_info_put(debug_info_t *db_info)
429 {
430 int i;
431
432 if (!db_info)
433 return;
434 if (atomic_dec_and_test(&db_info->ref_count)) {
435 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
436 if (!db_info->views[i])
437 continue;
438 debugfs_remove(db_info->debugfs_entries[i]);
439 }
440 debugfs_remove(db_info->debugfs_root_entry);
441 if(db_info == debug_area_first)
442 debug_area_first = db_info->next;
443 if(db_info == debug_area_last)
444 debug_area_last = db_info->prev;
445 if(db_info->prev) db_info->prev->next = db_info->next;
446 if(db_info->next) db_info->next->prev = db_info->prev;
447 debug_info_free(db_info);
448 }
449 }
450
451 /*
452 * debug_format_entry:
453 * - format one debug entry and return size of formated data
454 */
455
456 static int
457 debug_format_entry(file_private_info_t *p_info)
458 {
459 debug_info_t *id_snap = p_info->debug_info_snap;
460 struct debug_view *view = p_info->view;
461 debug_entry_t *act_entry;
462 size_t len = 0;
463 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
464 /* print prolog */
465 if (view->prolog_proc)
466 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
467 goto out;
468 }
469 if (!id_snap->areas) /* this is true, if we have a prolog only view */
470 goto out; /* or if 'pages_per_area' is 0 */
471 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
472 [p_info->act_page] + p_info->act_entry);
473
474 if (act_entry->id.stck == 0LL)
475 goto out; /* empty entry */
476 if (view->header_proc)
477 len += view->header_proc(id_snap, view, p_info->act_area,
478 act_entry, p_info->temp_buf + len);
479 if (view->format_proc)
480 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
481 DEBUG_DATA(act_entry));
482 out:
483 return len;
484 }
485
486 /*
487 * debug_next_entry:
488 * - goto next entry in p_info
489 */
490
491 static inline int
492 debug_next_entry(file_private_info_t *p_info)
493 {
494 debug_info_t *id;
495
496 id = p_info->debug_info_snap;
497 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
498 p_info->act_entry = 0;
499 p_info->act_page = 0;
500 goto out;
501 }
502 if(!id->areas)
503 return 1;
504 p_info->act_entry += id->entry_size;
505 /* switch to next page, if we reached the end of the page */
506 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
507 /* next page */
508 p_info->act_entry = 0;
509 p_info->act_page += 1;
510 if((p_info->act_page % id->pages_per_area) == 0) {
511 /* next area */
512 p_info->act_area++;
513 p_info->act_page=0;
514 }
515 if(p_info->act_area >= id->nr_areas)
516 return 1;
517 }
518 out:
519 return 0;
520 }
521
522 /*
523 * debug_output:
524 * - called for user read()
525 * - copies formated debug entries to the user buffer
526 */
527
528 static ssize_t
529 debug_output(struct file *file, /* file descriptor */
530 char __user *user_buf, /* user buffer */
531 size_t len, /* length of buffer */
532 loff_t *offset) /* offset in the file */
533 {
534 size_t count = 0;
535 size_t entry_offset;
536 file_private_info_t *p_info;
537
538 p_info = ((file_private_info_t *) file->private_data);
539 if (*offset != p_info->offset)
540 return -EPIPE;
541 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
542 return 0;
543 entry_offset = p_info->act_entry_offset;
544 while(count < len){
545 int formatted_line_size;
546 int formatted_line_residue;
547 int user_buf_residue;
548 size_t copy_size;
549
550 formatted_line_size = debug_format_entry(p_info);
551 formatted_line_residue = formatted_line_size - entry_offset;
552 user_buf_residue = len-count;
553 copy_size = min(user_buf_residue, formatted_line_residue);
554 if(copy_size){
555 if (copy_to_user(user_buf + count, p_info->temp_buf
556 + entry_offset, copy_size))
557 return -EFAULT;
558 count += copy_size;
559 entry_offset += copy_size;
560 }
561 if(copy_size == formatted_line_residue){
562 entry_offset = 0;
563 if(debug_next_entry(p_info))
564 goto out;
565 }
566 }
567 out:
568 p_info->offset = *offset + count;
569 p_info->act_entry_offset = entry_offset;
570 *offset = p_info->offset;
571 return count;
572 }
573
574 /*
575 * debug_input:
576 * - called for user write()
577 * - calls input function of view
578 */
579
580 static ssize_t
581 debug_input(struct file *file, const char __user *user_buf, size_t length,
582 loff_t *offset)
583 {
584 int rc = 0;
585 file_private_info_t *p_info;
586
587 mutex_lock(&debug_mutex);
588 p_info = ((file_private_info_t *) file->private_data);
589 if (p_info->view->input_proc)
590 rc = p_info->view->input_proc(p_info->debug_info_org,
591 p_info->view, file, user_buf,
592 length, offset);
593 else
594 rc = -EPERM;
595 mutex_unlock(&debug_mutex);
596 return rc; /* number of input characters */
597 }
598
599 /*
600 * debug_open:
601 * - called for user open()
602 * - copies formated output to private_data area of the file
603 * handle
604 */
605
606 static int
607 debug_open(struct inode *inode, struct file *file)
608 {
609 int i, rc = 0;
610 file_private_info_t *p_info;
611 debug_info_t *debug_info, *debug_info_snapshot;
612
613 mutex_lock(&debug_mutex);
614 debug_info = file_inode(file)->i_private;
615 /* find debug view */
616 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
617 if (!debug_info->views[i])
618 continue;
619 else if (debug_info->debugfs_entries[i] ==
620 file->f_path.dentry) {
621 goto found; /* found view ! */
622 }
623 }
624 /* no entry found */
625 rc = -EINVAL;
626 goto out;
627
628 found:
629
630 /* Make snapshot of current debug areas to get it consistent. */
631 /* To copy all the areas is only needed, if we have a view which */
632 /* formats the debug areas. */
633
634 if(!debug_info->views[i]->format_proc &&
635 !debug_info->views[i]->header_proc){
636 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
637 } else {
638 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
639 }
640
641 if(!debug_info_snapshot){
642 rc = -ENOMEM;
643 goto out;
644 }
645 p_info = kmalloc(sizeof(file_private_info_t),
646 GFP_KERNEL);
647 if(!p_info){
648 debug_info_free(debug_info_snapshot);
649 rc = -ENOMEM;
650 goto out;
651 }
652 p_info->offset = 0;
653 p_info->debug_info_snap = debug_info_snapshot;
654 p_info->debug_info_org = debug_info;
655 p_info->view = debug_info->views[i];
656 p_info->act_area = 0;
657 p_info->act_page = 0;
658 p_info->act_entry = DEBUG_PROLOG_ENTRY;
659 p_info->act_entry_offset = 0;
660 file->private_data = p_info;
661 debug_info_get(debug_info);
662 nonseekable_open(inode, file);
663 out:
664 mutex_unlock(&debug_mutex);
665 return rc;
666 }
667
668 /*
669 * debug_close:
670 * - called for user close()
671 * - deletes private_data area of the file handle
672 */
673
674 static int
675 debug_close(struct inode *inode, struct file *file)
676 {
677 file_private_info_t *p_info;
678 p_info = (file_private_info_t *) file->private_data;
679 if(p_info->debug_info_snap)
680 debug_info_free(p_info->debug_info_snap);
681 debug_info_put(p_info->debug_info_org);
682 kfree(file->private_data);
683 return 0; /* success */
684 }
685
686 /*
687 * debug_register_mode:
688 * - Creates and initializes debug area for the caller
689 * The mode parameter allows to specify access rights for the s390dbf files
690 * - Returns handle for debug area
691 */
692
693 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
694 int nr_areas, int buf_size, umode_t mode,
695 uid_t uid, gid_t gid)
696 {
697 debug_info_t *rc = NULL;
698
699 /* Since debugfs currently does not support uid/gid other than root, */
700 /* we do not allow gid/uid != 0 until we get support for that. */
701 if ((uid != 0) || (gid != 0))
702 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
703 BUG_ON(!initialized);
704 mutex_lock(&debug_mutex);
705
706 /* create new debug_info */
707
708 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
709 if(!rc)
710 goto out;
711 debug_register_view(rc, &debug_level_view);
712 debug_register_view(rc, &debug_flush_view);
713 debug_register_view(rc, &debug_pages_view);
714 out:
715 if (!rc){
716 pr_err("Registering debug feature %s failed\n", name);
717 }
718 mutex_unlock(&debug_mutex);
719 return rc;
720 }
721 EXPORT_SYMBOL(debug_register_mode);
722
723 /*
724 * debug_register:
725 * - creates and initializes debug area for the caller
726 * - returns handle for debug area
727 */
728
729 debug_info_t *debug_register(const char *name, int pages_per_area,
730 int nr_areas, int buf_size)
731 {
732 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
733 S_IRUSR | S_IWUSR, 0, 0);
734 }
735 EXPORT_SYMBOL(debug_register);
736
737 /*
738 * debug_unregister:
739 * - give back debug area
740 */
741
742 void
743 debug_unregister(debug_info_t * id)
744 {
745 if (!id)
746 goto out;
747 mutex_lock(&debug_mutex);
748 debug_info_put(id);
749 mutex_unlock(&debug_mutex);
750
751 out:
752 return;
753 }
754 EXPORT_SYMBOL(debug_unregister);
755
756 /*
757 * debug_set_size:
758 * - set area size (number of pages) and number of areas
759 */
760 static int
761 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
762 {
763 unsigned long flags;
764 debug_entry_t *** new_areas;
765 int rc=0;
766
767 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
768 return -EINVAL;
769 if(pages_per_area > 0){
770 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
771 if(!new_areas) {
772 pr_info("Allocating memory for %i pages failed\n",
773 pages_per_area);
774 rc = -ENOMEM;
775 goto out;
776 }
777 } else {
778 new_areas = NULL;
779 }
780 spin_lock_irqsave(&id->lock,flags);
781 debug_areas_free(id);
782 id->areas = new_areas;
783 id->nr_areas = nr_areas;
784 id->pages_per_area = pages_per_area;
785 id->active_area = 0;
786 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
787 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
788 spin_unlock_irqrestore(&id->lock,flags);
789 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
790 out:
791 return rc;
792 }
793
794 /*
795 * debug_set_level:
796 * - set actual debug level
797 */
798
799 void
800 debug_set_level(debug_info_t* id, int new_level)
801 {
802 unsigned long flags;
803 if(!id)
804 return;
805 spin_lock_irqsave(&id->lock,flags);
806 if(new_level == DEBUG_OFF_LEVEL){
807 id->level = DEBUG_OFF_LEVEL;
808 pr_info("%s: switched off\n",id->name);
809 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
810 pr_info("%s: level %i is out of range (%i - %i)\n",
811 id->name, new_level, 0, DEBUG_MAX_LEVEL);
812 } else {
813 id->level = new_level;
814 }
815 spin_unlock_irqrestore(&id->lock,flags);
816 }
817 EXPORT_SYMBOL(debug_set_level);
818
819 /*
820 * proceed_active_entry:
821 * - set active entry to next in the ring buffer
822 */
823
824 static inline void
825 proceed_active_entry(debug_info_t * id)
826 {
827 if ((id->active_entries[id->active_area] += id->entry_size)
828 > (PAGE_SIZE - id->entry_size)){
829 id->active_entries[id->active_area] = 0;
830 id->active_pages[id->active_area] =
831 (id->active_pages[id->active_area] + 1) %
832 id->pages_per_area;
833 }
834 }
835
836 /*
837 * proceed_active_area:
838 * - set active area to next in the ring buffer
839 */
840
841 static inline void
842 proceed_active_area(debug_info_t * id)
843 {
844 id->active_area++;
845 id->active_area = id->active_area % id->nr_areas;
846 }
847
848 /*
849 * get_active_entry:
850 */
851
852 static inline debug_entry_t*
853 get_active_entry(debug_info_t * id)
854 {
855 return (debug_entry_t *) (((char *) id->areas[id->active_area]
856 [id->active_pages[id->active_area]]) +
857 id->active_entries[id->active_area]);
858 }
859
860 /*
861 * debug_finish_entry:
862 * - set timestamp, caller address, cpu number etc.
863 */
864
865 static inline void
866 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
867 int exception)
868 {
869 active->id.stck = get_tod_clock_fast();
870 active->id.fields.cpuid = smp_processor_id();
871 active->caller = __builtin_return_address(0);
872 active->id.fields.exception = exception;
873 active->id.fields.level = level;
874 proceed_active_entry(id);
875 if(exception)
876 proceed_active_area(id);
877 }
878
879 static int debug_stoppable=1;
880 static int debug_active=1;
881
882 #define CTL_S390DBF_STOPPABLE 5678
883 #define CTL_S390DBF_ACTIVE 5679
884
885 /*
886 * proc handler for the running debug_active sysctl
887 * always allow read, allow write only if debug_stoppable is set or
888 * if debug_active is already off
889 */
890 static int
891 s390dbf_procactive(struct ctl_table *table, int write,
892 void __user *buffer, size_t *lenp, loff_t *ppos)
893 {
894 if (!write || debug_stoppable || !debug_active)
895 return proc_dointvec(table, write, buffer, lenp, ppos);
896 else
897 return 0;
898 }
899
900
901 static struct ctl_table s390dbf_table[] = {
902 {
903 .procname = "debug_stoppable",
904 .data = &debug_stoppable,
905 .maxlen = sizeof(int),
906 .mode = S_IRUGO | S_IWUSR,
907 .proc_handler = proc_dointvec,
908 },
909 {
910 .procname = "debug_active",
911 .data = &debug_active,
912 .maxlen = sizeof(int),
913 .mode = S_IRUGO | S_IWUSR,
914 .proc_handler = s390dbf_procactive,
915 },
916 { }
917 };
918
919 static struct ctl_table s390dbf_dir_table[] = {
920 {
921 .procname = "s390dbf",
922 .maxlen = 0,
923 .mode = S_IRUGO | S_IXUGO,
924 .child = s390dbf_table,
925 },
926 { }
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 EXPORT_SYMBOL(debug_stop_all);
938
939 void debug_set_critical(void)
940 {
941 debug_critical = 1;
942 }
943
944 /*
945 * debug_event_common:
946 * - write debug entry with given size
947 */
948
949 debug_entry_t*
950 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
951 {
952 unsigned long flags;
953 debug_entry_t *active;
954
955 if (!debug_active || !id->areas)
956 return NULL;
957 if (debug_critical) {
958 if (!spin_trylock_irqsave(&id->lock, flags))
959 return NULL;
960 } else
961 spin_lock_irqsave(&id->lock, flags);
962 active = get_active_entry(id);
963 memset(DEBUG_DATA(active), 0, id->buf_size);
964 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
965 debug_finish_entry(id, active, level, 0);
966 spin_unlock_irqrestore(&id->lock, flags);
967
968 return active;
969 }
970 EXPORT_SYMBOL(debug_event_common);
971
972 /*
973 * debug_exception_common:
974 * - write debug entry with given size and switch to next debug area
975 */
976
977 debug_entry_t
978 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
979 {
980 unsigned long flags;
981 debug_entry_t *active;
982
983 if (!debug_active || !id->areas)
984 return NULL;
985 if (debug_critical) {
986 if (!spin_trylock_irqsave(&id->lock, flags))
987 return NULL;
988 } else
989 spin_lock_irqsave(&id->lock, flags);
990 active = get_active_entry(id);
991 memset(DEBUG_DATA(active), 0, id->buf_size);
992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
993 debug_finish_entry(id, active, level, 1);
994 spin_unlock_irqrestore(&id->lock, flags);
995
996 return active;
997 }
998 EXPORT_SYMBOL(debug_exception_common);
999
1000 /*
1001 * counts arguments in format string for sprintf view
1002 */
1003
1004 static inline int
1005 debug_count_numargs(char *string)
1006 {
1007 int numargs=0;
1008
1009 while(*string) {
1010 if(*string++=='%')
1011 numargs++;
1012 }
1013 return(numargs);
1014 }
1015
1016 /*
1017 * debug_sprintf_event:
1018 */
1019
1020 debug_entry_t*
1021 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1022 {
1023 va_list ap;
1024 int numargs,idx;
1025 unsigned long flags;
1026 debug_sprintf_entry_t *curr_event;
1027 debug_entry_t *active;
1028
1029 if (!debug_active || !id->areas)
1030 return NULL;
1031 numargs=debug_count_numargs(string);
1032
1033 if (debug_critical) {
1034 if (!spin_trylock_irqsave(&id->lock, flags))
1035 return NULL;
1036 } else
1037 spin_lock_irqsave(&id->lock, flags);
1038 active = get_active_entry(id);
1039 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1040 va_start(ap,string);
1041 curr_event->string=string;
1042 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1043 curr_event->args[idx]=va_arg(ap,long);
1044 va_end(ap);
1045 debug_finish_entry(id, active, level, 0);
1046 spin_unlock_irqrestore(&id->lock, flags);
1047
1048 return active;
1049 }
1050 EXPORT_SYMBOL(__debug_sprintf_event);
1051
1052 /*
1053 * debug_sprintf_exception:
1054 */
1055
1056 debug_entry_t*
1057 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1058 {
1059 va_list ap;
1060 int numargs,idx;
1061 unsigned long flags;
1062 debug_sprintf_entry_t *curr_event;
1063 debug_entry_t *active;
1064
1065 if (!debug_active || !id->areas)
1066 return NULL;
1067
1068 numargs=debug_count_numargs(string);
1069
1070 if (debug_critical) {
1071 if (!spin_trylock_irqsave(&id->lock, flags))
1072 return NULL;
1073 } else
1074 spin_lock_irqsave(&id->lock, flags);
1075 active = get_active_entry(id);
1076 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1077 va_start(ap,string);
1078 curr_event->string=string;
1079 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1080 curr_event->args[idx]=va_arg(ap,long);
1081 va_end(ap);
1082 debug_finish_entry(id, active, level, 1);
1083 spin_unlock_irqrestore(&id->lock, flags);
1084
1085 return active;
1086 }
1087 EXPORT_SYMBOL(__debug_sprintf_exception);
1088
1089 /*
1090 * debug_register_view:
1091 */
1092
1093 int
1094 debug_register_view(debug_info_t * id, struct debug_view *view)
1095 {
1096 int rc = 0;
1097 int i;
1098 unsigned long flags;
1099 umode_t mode;
1100 struct dentry *pde;
1101
1102 if (!id)
1103 goto out;
1104 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1105 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1106 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1107 if (!view->input_proc)
1108 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1109 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1110 id , &debug_file_ops);
1111 if (!pde){
1112 pr_err("Registering view %s/%s failed due to out of "
1113 "memory\n", id->name,view->name);
1114 rc = -1;
1115 goto out;
1116 }
1117 spin_lock_irqsave(&id->lock, flags);
1118 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1119 if (!id->views[i])
1120 break;
1121 }
1122 if (i == DEBUG_MAX_VIEWS) {
1123 pr_err("Registering view %s/%s would exceed the maximum "
1124 "number of views %i\n", id->name, view->name, i);
1125 rc = -1;
1126 } else {
1127 id->views[i] = view;
1128 id->debugfs_entries[i] = pde;
1129 }
1130 spin_unlock_irqrestore(&id->lock, flags);
1131 if (rc)
1132 debugfs_remove(pde);
1133 out:
1134 return rc;
1135 }
1136 EXPORT_SYMBOL(debug_register_view);
1137
1138 /*
1139 * debug_unregister_view:
1140 */
1141
1142 int
1143 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1144 {
1145 struct dentry *dentry = NULL;
1146 unsigned long flags;
1147 int i, rc = 0;
1148
1149 if (!id)
1150 goto out;
1151 spin_lock_irqsave(&id->lock, flags);
1152 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1153 if (id->views[i] == view)
1154 break;
1155 }
1156 if (i == DEBUG_MAX_VIEWS)
1157 rc = -1;
1158 else {
1159 dentry = id->debugfs_entries[i];
1160 id->views[i] = NULL;
1161 id->debugfs_entries[i] = NULL;
1162 }
1163 spin_unlock_irqrestore(&id->lock, flags);
1164 debugfs_remove(dentry);
1165 out:
1166 return rc;
1167 }
1168 EXPORT_SYMBOL(debug_unregister_view);
1169
1170 static inline char *
1171 debug_get_user_string(const char __user *user_buf, size_t user_len)
1172 {
1173 char* buffer;
1174
1175 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1176 if (!buffer)
1177 return ERR_PTR(-ENOMEM);
1178 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1179 kfree(buffer);
1180 return ERR_PTR(-EFAULT);
1181 }
1182 /* got the string, now strip linefeed. */
1183 if (buffer[user_len - 1] == '\n')
1184 buffer[user_len - 1] = 0;
1185 else
1186 buffer[user_len] = 0;
1187 return buffer;
1188 }
1189
1190 static inline int
1191 debug_get_uint(char *buf)
1192 {
1193 int rc;
1194
1195 buf = skip_spaces(buf);
1196 rc = simple_strtoul(buf, &buf, 10);
1197 if(*buf){
1198 rc = -EINVAL;
1199 }
1200 return rc;
1201 }
1202
1203 /*
1204 * functions for debug-views
1205 ***********************************
1206 */
1207
1208 /*
1209 * prints out actual debug level
1210 */
1211
1212 static int
1213 debug_prolog_pages_fn(debug_info_t * id,
1214 struct debug_view *view, char *out_buf)
1215 {
1216 return sprintf(out_buf, "%i\n", id->pages_per_area);
1217 }
1218
1219 /*
1220 * reads new size (number of pages per debug area)
1221 */
1222
1223 static int
1224 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1225 struct file *file, const char __user *user_buf,
1226 size_t user_len, loff_t * offset)
1227 {
1228 char *str;
1229 int rc,new_pages;
1230
1231 if (user_len > 0x10000)
1232 user_len = 0x10000;
1233 if (*offset != 0){
1234 rc = -EPIPE;
1235 goto out;
1236 }
1237 str = debug_get_user_string(user_buf,user_len);
1238 if(IS_ERR(str)){
1239 rc = PTR_ERR(str);
1240 goto out;
1241 }
1242 new_pages = debug_get_uint(str);
1243 if(new_pages < 0){
1244 rc = -EINVAL;
1245 goto free_str;
1246 }
1247 rc = debug_set_size(id,id->nr_areas, new_pages);
1248 if(rc != 0){
1249 rc = -EINVAL;
1250 goto free_str;
1251 }
1252 rc = user_len;
1253 free_str:
1254 kfree(str);
1255 out:
1256 *offset += user_len;
1257 return rc; /* number of input characters */
1258 }
1259
1260 /*
1261 * prints out actual debug level
1262 */
1263
1264 static int
1265 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1266 {
1267 int rc = 0;
1268
1269 if(id->level == DEBUG_OFF_LEVEL) {
1270 rc = sprintf(out_buf,"-\n");
1271 }
1272 else {
1273 rc = sprintf(out_buf, "%i\n", id->level);
1274 }
1275 return rc;
1276 }
1277
1278 /*
1279 * reads new debug level
1280 */
1281
1282 static int
1283 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1284 struct file *file, const char __user *user_buf,
1285 size_t user_len, loff_t * offset)
1286 {
1287 char *str;
1288 int rc,new_level;
1289
1290 if (user_len > 0x10000)
1291 user_len = 0x10000;
1292 if (*offset != 0){
1293 rc = -EPIPE;
1294 goto out;
1295 }
1296 str = debug_get_user_string(user_buf,user_len);
1297 if(IS_ERR(str)){
1298 rc = PTR_ERR(str);
1299 goto out;
1300 }
1301 if(str[0] == '-'){
1302 debug_set_level(id, DEBUG_OFF_LEVEL);
1303 rc = user_len;
1304 goto free_str;
1305 } else {
1306 new_level = debug_get_uint(str);
1307 }
1308 if(new_level < 0) {
1309 pr_warn("%s is not a valid level for a debug feature\n", str);
1310 rc = -EINVAL;
1311 } else {
1312 debug_set_level(id, new_level);
1313 rc = user_len;
1314 }
1315 free_str:
1316 kfree(str);
1317 out:
1318 *offset += user_len;
1319 return rc; /* number of input characters */
1320 }
1321
1322
1323 /*
1324 * flushes debug areas
1325 */
1326
1327 static void debug_flush(debug_info_t* id, int area)
1328 {
1329 unsigned long flags;
1330 int i,j;
1331
1332 if(!id || !id->areas)
1333 return;
1334 spin_lock_irqsave(&id->lock,flags);
1335 if(area == DEBUG_FLUSH_ALL){
1336 id->active_area = 0;
1337 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1338 for (i = 0; i < id->nr_areas; i++) {
1339 id->active_pages[i] = 0;
1340 for(j = 0; j < id->pages_per_area; j++) {
1341 memset(id->areas[i][j], 0, PAGE_SIZE);
1342 }
1343 }
1344 } else if(area >= 0 && area < id->nr_areas) {
1345 id->active_entries[area] = 0;
1346 id->active_pages[area] = 0;
1347 for(i = 0; i < id->pages_per_area; i++) {
1348 memset(id->areas[area][i],0,PAGE_SIZE);
1349 }
1350 }
1351 spin_unlock_irqrestore(&id->lock,flags);
1352 }
1353
1354 /*
1355 * view function: flushes debug areas
1356 */
1357
1358 static int
1359 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1360 struct file *file, const char __user *user_buf,
1361 size_t user_len, loff_t * offset)
1362 {
1363 char input_buf[1];
1364 int rc = user_len;
1365
1366 if (user_len > 0x10000)
1367 user_len = 0x10000;
1368 if (*offset != 0){
1369 rc = -EPIPE;
1370 goto out;
1371 }
1372 if (copy_from_user(input_buf, user_buf, 1)){
1373 rc = -EFAULT;
1374 goto out;
1375 }
1376 if(input_buf[0] == '-') {
1377 debug_flush(id, DEBUG_FLUSH_ALL);
1378 goto out;
1379 }
1380 if (isdigit(input_buf[0])) {
1381 int area = ((int) input_buf[0] - (int) '0');
1382 debug_flush(id, area);
1383 goto out;
1384 }
1385
1386 pr_info("Flushing debug data failed because %c is not a valid "
1387 "area\n", input_buf[0]);
1388
1389 out:
1390 *offset += user_len;
1391 return rc; /* number of input characters */
1392 }
1393
1394 /*
1395 * prints debug header in raw format
1396 */
1397
1398 static int
1399 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1400 int area, debug_entry_t * entry, char *out_buf)
1401 {
1402 int rc;
1403
1404 rc = sizeof(debug_entry_t);
1405 memcpy(out_buf,entry,sizeof(debug_entry_t));
1406 return rc;
1407 }
1408
1409 /*
1410 * prints debug data in raw format
1411 */
1412
1413 static int
1414 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1415 char *out_buf, const char *in_buf)
1416 {
1417 int rc;
1418
1419 rc = id->buf_size;
1420 memcpy(out_buf, in_buf, id->buf_size);
1421 return rc;
1422 }
1423
1424 /*
1425 * prints debug data in hex/ascii format
1426 */
1427
1428 static int
1429 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1430 char *out_buf, const char *in_buf)
1431 {
1432 int i, rc = 0;
1433
1434 for (i = 0; i < id->buf_size; i++) {
1435 rc += sprintf(out_buf + rc, "%02x ",
1436 ((unsigned char *) in_buf)[i]);
1437 }
1438 rc += sprintf(out_buf + rc, "| ");
1439 for (i = 0; i < id->buf_size; i++) {
1440 unsigned char c = in_buf[i];
1441 if (isascii(c) && isprint(c))
1442 rc += sprintf(out_buf + rc, "%c", c);
1443 else
1444 rc += sprintf(out_buf + rc, ".");
1445 }
1446 rc += sprintf(out_buf + rc, "\n");
1447 return rc;
1448 }
1449
1450 /*
1451 * prints header for debug entry
1452 */
1453
1454 int
1455 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1456 int area, debug_entry_t * entry, char *out_buf)
1457 {
1458 struct timespec64 time_spec;
1459 char *except_str;
1460 unsigned long caller;
1461 int rc = 0;
1462 unsigned int level;
1463
1464 level = entry->id.fields.level;
1465 stck_to_timespec64(entry->id.stck, &time_spec);
1466
1467 if (entry->id.fields.exception)
1468 except_str = "*";
1469 else
1470 except_str = "-";
1471 caller = (unsigned long) entry->caller;
1472 rc += sprintf(out_buf, "%02i %011lld:%06lu %1u %1s %02i %p ",
1473 area, (long long)time_spec.tv_sec,
1474 time_spec.tv_nsec / 1000, level, except_str,
1475 entry->id.fields.cpuid, (void *)caller);
1476 return rc;
1477 }
1478 EXPORT_SYMBOL(debug_dflt_header_fn);
1479
1480 /*
1481 * prints debug data sprintf-formated:
1482 * debug_sprinf_event/exception calls must be used together with this view
1483 */
1484
1485 #define DEBUG_SPRINTF_MAX_ARGS 10
1486
1487 static int
1488 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1489 char *out_buf, debug_sprintf_entry_t *curr_event)
1490 {
1491 int num_longs, num_used_args = 0,i, rc = 0;
1492 int index[DEBUG_SPRINTF_MAX_ARGS];
1493
1494 /* count of longs fit into one entry */
1495 num_longs = id->buf_size / sizeof(long);
1496
1497 if(num_longs < 1)
1498 goto out; /* bufsize of entry too small */
1499 if(num_longs == 1) {
1500 /* no args, we use only the string */
1501 strcpy(out_buf, curr_event->string);
1502 rc = strlen(curr_event->string);
1503 goto out;
1504 }
1505
1506 /* number of arguments used for sprintf (without the format string) */
1507 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1508
1509 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1510
1511 for(i = 0; i < num_used_args; i++)
1512 index[i] = i;
1513
1514 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1515 curr_event->args[index[1]], curr_event->args[index[2]],
1516 curr_event->args[index[3]], curr_event->args[index[4]],
1517 curr_event->args[index[5]], curr_event->args[index[6]],
1518 curr_event->args[index[7]], curr_event->args[index[8]],
1519 curr_event->args[index[9]]);
1520
1521 out:
1522
1523 return rc;
1524 }
1525
1526 /*
1527 * debug_init:
1528 * - is called exactly once to initialize the debug feature
1529 */
1530 static int __init debug_init(void)
1531 {
1532 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1533 mutex_lock(&debug_mutex);
1534 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1535 initialized = 1;
1536 mutex_unlock(&debug_mutex);
1537 return 0;
1538 }
1539 postcore_initcall(debug_init);
Linux with added FPC-III support