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Merge tag 'for-4.2' of git://git.infradead.org/battery-2.6
[mirror_ubuntu-focal-kernel.git] / arch / s390 / kernel / debug.c
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_warning("Root becomes the owner of all s390dbf files "
703 "in sysfs\n");
704 BUG_ON(!initialized);
705 mutex_lock(&debug_mutex);
706
707 /* create new debug_info */
708
709 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
710 if(!rc)
711 goto out;
712 debug_register_view(rc, &debug_level_view);
713 debug_register_view(rc, &debug_flush_view);
714 debug_register_view(rc, &debug_pages_view);
715 out:
716 if (!rc){
717 pr_err("Registering debug feature %s failed\n", name);
718 }
719 mutex_unlock(&debug_mutex);
720 return rc;
721 }
722 EXPORT_SYMBOL(debug_register_mode);
723
724 /*
725 * debug_register:
726 * - creates and initializes debug area for the caller
727 * - returns handle for debug area
728 */
729
730 debug_info_t *debug_register(const char *name, int pages_per_area,
731 int nr_areas, int buf_size)
732 {
733 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
734 S_IRUSR | S_IWUSR, 0, 0);
735 }
736 EXPORT_SYMBOL(debug_register);
737
738 /*
739 * debug_unregister:
740 * - give back debug area
741 */
742
743 void
744 debug_unregister(debug_info_t * id)
745 {
746 if (!id)
747 goto out;
748 mutex_lock(&debug_mutex);
749 debug_info_put(id);
750 mutex_unlock(&debug_mutex);
751
752 out:
753 return;
754 }
755 EXPORT_SYMBOL(debug_unregister);
756
757 /*
758 * debug_set_size:
759 * - set area size (number of pages) and number of areas
760 */
761 static int
762 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
763 {
764 unsigned long flags;
765 debug_entry_t *** new_areas;
766 int rc=0;
767
768 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
769 return -EINVAL;
770 if(pages_per_area > 0){
771 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
772 if(!new_areas) {
773 pr_info("Allocating memory for %i pages failed\n",
774 pages_per_area);
775 rc = -ENOMEM;
776 goto out;
777 }
778 } else {
779 new_areas = NULL;
780 }
781 spin_lock_irqsave(&id->lock,flags);
782 debug_areas_free(id);
783 id->areas = new_areas;
784 id->nr_areas = nr_areas;
785 id->pages_per_area = pages_per_area;
786 id->active_area = 0;
787 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
788 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
789 spin_unlock_irqrestore(&id->lock,flags);
790 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
791 out:
792 return rc;
793 }
794
795 /*
796 * debug_set_level:
797 * - set actual debug level
798 */
799
800 void
801 debug_set_level(debug_info_t* id, int new_level)
802 {
803 unsigned long flags;
804 if(!id)
805 return;
806 spin_lock_irqsave(&id->lock,flags);
807 if(new_level == DEBUG_OFF_LEVEL){
808 id->level = DEBUG_OFF_LEVEL;
809 pr_info("%s: switched off\n",id->name);
810 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
811 pr_info("%s: level %i is out of range (%i - %i)\n",
812 id->name, new_level, 0, DEBUG_MAX_LEVEL);
813 } else {
814 id->level = new_level;
815 }
816 spin_unlock_irqrestore(&id->lock,flags);
817 }
818 EXPORT_SYMBOL(debug_set_level);
819
820 /*
821 * proceed_active_entry:
822 * - set active entry to next in the ring buffer
823 */
824
825 static inline void
826 proceed_active_entry(debug_info_t * id)
827 {
828 if ((id->active_entries[id->active_area] += id->entry_size)
829 > (PAGE_SIZE - id->entry_size)){
830 id->active_entries[id->active_area] = 0;
831 id->active_pages[id->active_area] =
832 (id->active_pages[id->active_area] + 1) %
833 id->pages_per_area;
834 }
835 }
836
837 /*
838 * proceed_active_area:
839 * - set active area to next in the ring buffer
840 */
841
842 static inline void
843 proceed_active_area(debug_info_t * id)
844 {
845 id->active_area++;
846 id->active_area = id->active_area % id->nr_areas;
847 }
848
849 /*
850 * get_active_entry:
851 */
852
853 static inline debug_entry_t*
854 get_active_entry(debug_info_t * id)
855 {
856 return (debug_entry_t *) (((char *) id->areas[id->active_area]
857 [id->active_pages[id->active_area]]) +
858 id->active_entries[id->active_area]);
859 }
860
861 /*
862 * debug_finish_entry:
863 * - set timestamp, caller address, cpu number etc.
864 */
865
866 static inline void
867 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
868 int exception)
869 {
870 active->id.stck = get_tod_clock_fast();
871 active->id.fields.cpuid = smp_processor_id();
872 active->caller = __builtin_return_address(0);
873 active->id.fields.exception = exception;
874 active->id.fields.level = level;
875 proceed_active_entry(id);
876 if(exception)
877 proceed_active_area(id);
878 }
879
880 static int debug_stoppable=1;
881 static int debug_active=1;
882
883 #define CTL_S390DBF_STOPPABLE 5678
884 #define CTL_S390DBF_ACTIVE 5679
885
886 /*
887 * proc handler for the running debug_active sysctl
888 * always allow read, allow write only if debug_stoppable is set or
889 * if debug_active is already off
890 */
891 static int
892 s390dbf_procactive(struct ctl_table *table, int write,
893 void __user *buffer, size_t *lenp, loff_t *ppos)
894 {
895 if (!write || debug_stoppable || !debug_active)
896 return proc_dointvec(table, write, buffer, lenp, ppos);
897 else
898 return 0;
899 }
900
901
902 static struct ctl_table s390dbf_table[] = {
903 {
904 .procname = "debug_stoppable",
905 .data = &debug_stoppable,
906 .maxlen = sizeof(int),
907 .mode = S_IRUGO | S_IWUSR,
908 .proc_handler = proc_dointvec,
909 },
910 {
911 .procname = "debug_active",
912 .data = &debug_active,
913 .maxlen = sizeof(int),
914 .mode = S_IRUGO | S_IWUSR,
915 .proc_handler = s390dbf_procactive,
916 },
917 { }
918 };
919
920 static struct ctl_table s390dbf_dir_table[] = {
921 {
922 .procname = "s390dbf",
923 .maxlen = 0,
924 .mode = S_IRUGO | S_IXUGO,
925 .child = s390dbf_table,
926 },
927 { }
928 };
929
930 static struct ctl_table_header *s390dbf_sysctl_header;
931
932 void
933 debug_stop_all(void)
934 {
935 if (debug_stoppable)
936 debug_active = 0;
937 }
938 EXPORT_SYMBOL(debug_stop_all);
939
940 void debug_set_critical(void)
941 {
942 debug_critical = 1;
943 }
944
945 /*
946 * debug_event_common:
947 * - write debug entry with given size
948 */
949
950 debug_entry_t*
951 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
952 {
953 unsigned long flags;
954 debug_entry_t *active;
955
956 if (!debug_active || !id->areas)
957 return NULL;
958 if (debug_critical) {
959 if (!spin_trylock_irqsave(&id->lock, flags))
960 return NULL;
961 } else
962 spin_lock_irqsave(&id->lock, flags);
963 active = get_active_entry(id);
964 memset(DEBUG_DATA(active), 0, id->buf_size);
965 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
966 debug_finish_entry(id, active, level, 0);
967 spin_unlock_irqrestore(&id->lock, flags);
968
969 return active;
970 }
971 EXPORT_SYMBOL(debug_event_common);
972
973 /*
974 * debug_exception_common:
975 * - write debug entry with given size and switch to next debug area
976 */
977
978 debug_entry_t
979 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
980 {
981 unsigned long flags;
982 debug_entry_t *active;
983
984 if (!debug_active || !id->areas)
985 return NULL;
986 if (debug_critical) {
987 if (!spin_trylock_irqsave(&id->lock, flags))
988 return NULL;
989 } else
990 spin_lock_irqsave(&id->lock, flags);
991 active = get_active_entry(id);
992 memset(DEBUG_DATA(active), 0, id->buf_size);
993 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
994 debug_finish_entry(id, active, level, 1);
995 spin_unlock_irqrestore(&id->lock, flags);
996
997 return active;
998 }
999 EXPORT_SYMBOL(debug_exception_common);
1000
1001 /*
1002 * counts arguments in format string for sprintf view
1003 */
1004
1005 static inline int
1006 debug_count_numargs(char *string)
1007 {
1008 int numargs=0;
1009
1010 while(*string) {
1011 if(*string++=='%')
1012 numargs++;
1013 }
1014 return(numargs);
1015 }
1016
1017 /*
1018 * debug_sprintf_event:
1019 */
1020
1021 debug_entry_t*
1022 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1023 {
1024 va_list ap;
1025 int numargs,idx;
1026 unsigned long flags;
1027 debug_sprintf_entry_t *curr_event;
1028 debug_entry_t *active;
1029
1030 if (!debug_active || !id->areas)
1031 return NULL;
1032 numargs=debug_count_numargs(string);
1033
1034 if (debug_critical) {
1035 if (!spin_trylock_irqsave(&id->lock, flags))
1036 return NULL;
1037 } else
1038 spin_lock_irqsave(&id->lock, flags);
1039 active = get_active_entry(id);
1040 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1041 va_start(ap,string);
1042 curr_event->string=string;
1043 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1044 curr_event->args[idx]=va_arg(ap,long);
1045 va_end(ap);
1046 debug_finish_entry(id, active, level, 0);
1047 spin_unlock_irqrestore(&id->lock, flags);
1048
1049 return active;
1050 }
1051 EXPORT_SYMBOL(__debug_sprintf_event);
1052
1053 /*
1054 * debug_sprintf_exception:
1055 */
1056
1057 debug_entry_t*
1058 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1059 {
1060 va_list ap;
1061 int numargs,idx;
1062 unsigned long flags;
1063 debug_sprintf_entry_t *curr_event;
1064 debug_entry_t *active;
1065
1066 if (!debug_active || !id->areas)
1067 return NULL;
1068
1069 numargs=debug_count_numargs(string);
1070
1071 if (debug_critical) {
1072 if (!spin_trylock_irqsave(&id->lock, flags))
1073 return NULL;
1074 } else
1075 spin_lock_irqsave(&id->lock, flags);
1076 active = get_active_entry(id);
1077 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1078 va_start(ap,string);
1079 curr_event->string=string;
1080 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1081 curr_event->args[idx]=va_arg(ap,long);
1082 va_end(ap);
1083 debug_finish_entry(id, active, level, 1);
1084 spin_unlock_irqrestore(&id->lock, flags);
1085
1086 return active;
1087 }
1088 EXPORT_SYMBOL(__debug_sprintf_exception);
1089
1090 /*
1091 * debug_register_view:
1092 */
1093
1094 int
1095 debug_register_view(debug_info_t * id, struct debug_view *view)
1096 {
1097 int rc = 0;
1098 int i;
1099 unsigned long flags;
1100 umode_t mode;
1101 struct dentry *pde;
1102
1103 if (!id)
1104 goto out;
1105 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1106 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1107 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1108 if (!view->input_proc)
1109 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1110 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1111 id , &debug_file_ops);
1112 if (!pde){
1113 pr_err("Registering view %s/%s failed due to out of "
1114 "memory\n", id->name,view->name);
1115 rc = -1;
1116 goto out;
1117 }
1118 spin_lock_irqsave(&id->lock, flags);
1119 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1120 if (!id->views[i])
1121 break;
1122 }
1123 if (i == DEBUG_MAX_VIEWS) {
1124 pr_err("Registering view %s/%s would exceed the maximum "
1125 "number of views %i\n", id->name, view->name, i);
1126 rc = -1;
1127 } else {
1128 id->views[i] = view;
1129 id->debugfs_entries[i] = pde;
1130 }
1131 spin_unlock_irqrestore(&id->lock, flags);
1132 if (rc)
1133 debugfs_remove(pde);
1134 out:
1135 return rc;
1136 }
1137 EXPORT_SYMBOL(debug_register_view);
1138
1139 /*
1140 * debug_unregister_view:
1141 */
1142
1143 int
1144 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1145 {
1146 struct dentry *dentry = NULL;
1147 unsigned long flags;
1148 int i, rc = 0;
1149
1150 if (!id)
1151 goto out;
1152 spin_lock_irqsave(&id->lock, flags);
1153 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1154 if (id->views[i] == view)
1155 break;
1156 }
1157 if (i == DEBUG_MAX_VIEWS)
1158 rc = -1;
1159 else {
1160 dentry = id->debugfs_entries[i];
1161 id->views[i] = NULL;
1162 id->debugfs_entries[i] = NULL;
1163 }
1164 spin_unlock_irqrestore(&id->lock, flags);
1165 debugfs_remove(dentry);
1166 out:
1167 return rc;
1168 }
1169 EXPORT_SYMBOL(debug_unregister_view);
1170
1171 static inline char *
1172 debug_get_user_string(const char __user *user_buf, size_t user_len)
1173 {
1174 char* buffer;
1175
1176 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1177 if (!buffer)
1178 return ERR_PTR(-ENOMEM);
1179 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1180 kfree(buffer);
1181 return ERR_PTR(-EFAULT);
1182 }
1183 /* got the string, now strip linefeed. */
1184 if (buffer[user_len - 1] == '\n')
1185 buffer[user_len - 1] = 0;
1186 else
1187 buffer[user_len] = 0;
1188 return buffer;
1189 }
1190
1191 static inline int
1192 debug_get_uint(char *buf)
1193 {
1194 int rc;
1195
1196 buf = skip_spaces(buf);
1197 rc = simple_strtoul(buf, &buf, 10);
1198 if(*buf){
1199 rc = -EINVAL;
1200 }
1201 return rc;
1202 }
1203
1204 /*
1205 * functions for debug-views
1206 ***********************************
1207 */
1208
1209 /*
1210 * prints out actual debug level
1211 */
1212
1213 static int
1214 debug_prolog_pages_fn(debug_info_t * id,
1215 struct debug_view *view, char *out_buf)
1216 {
1217 return sprintf(out_buf, "%i\n", id->pages_per_area);
1218 }
1219
1220 /*
1221 * reads new size (number of pages per debug area)
1222 */
1223
1224 static int
1225 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1226 struct file *file, const char __user *user_buf,
1227 size_t user_len, loff_t * offset)
1228 {
1229 char *str;
1230 int rc,new_pages;
1231
1232 if (user_len > 0x10000)
1233 user_len = 0x10000;
1234 if (*offset != 0){
1235 rc = -EPIPE;
1236 goto out;
1237 }
1238 str = debug_get_user_string(user_buf,user_len);
1239 if(IS_ERR(str)){
1240 rc = PTR_ERR(str);
1241 goto out;
1242 }
1243 new_pages = debug_get_uint(str);
1244 if(new_pages < 0){
1245 rc = -EINVAL;
1246 goto free_str;
1247 }
1248 rc = debug_set_size(id,id->nr_areas, new_pages);
1249 if(rc != 0){
1250 rc = -EINVAL;
1251 goto free_str;
1252 }
1253 rc = user_len;
1254 free_str:
1255 kfree(str);
1256 out:
1257 *offset += user_len;
1258 return rc; /* number of input characters */
1259 }
1260
1261 /*
1262 * prints out actual debug level
1263 */
1264
1265 static int
1266 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1267 {
1268 int rc = 0;
1269
1270 if(id->level == DEBUG_OFF_LEVEL) {
1271 rc = sprintf(out_buf,"-\n");
1272 }
1273 else {
1274 rc = sprintf(out_buf, "%i\n", id->level);
1275 }
1276 return rc;
1277 }
1278
1279 /*
1280 * reads new debug level
1281 */
1282
1283 static int
1284 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1285 struct file *file, const char __user *user_buf,
1286 size_t user_len, loff_t * offset)
1287 {
1288 char *str;
1289 int rc,new_level;
1290
1291 if (user_len > 0x10000)
1292 user_len = 0x10000;
1293 if (*offset != 0){
1294 rc = -EPIPE;
1295 goto out;
1296 }
1297 str = debug_get_user_string(user_buf,user_len);
1298 if(IS_ERR(str)){
1299 rc = PTR_ERR(str);
1300 goto out;
1301 }
1302 if(str[0] == '-'){
1303 debug_set_level(id, DEBUG_OFF_LEVEL);
1304 rc = user_len;
1305 goto free_str;
1306 } else {
1307 new_level = debug_get_uint(str);
1308 }
1309 if(new_level < 0) {
1310 pr_warning("%s is not a valid level for a debug "
1311 "feature\n", str);
1312 rc = -EINVAL;
1313 } else {
1314 debug_set_level(id, new_level);
1315 rc = user_len;
1316 }
1317 free_str:
1318 kfree(str);
1319 out:
1320 *offset += user_len;
1321 return rc; /* number of input characters */
1322 }
1323
1324
1325 /*
1326 * flushes debug areas
1327 */
1328
1329 static void debug_flush(debug_info_t* id, int area)
1330 {
1331 unsigned long flags;
1332 int i,j;
1333
1334 if(!id || !id->areas)
1335 return;
1336 spin_lock_irqsave(&id->lock,flags);
1337 if(area == DEBUG_FLUSH_ALL){
1338 id->active_area = 0;
1339 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1340 for (i = 0; i < id->nr_areas; i++) {
1341 id->active_pages[i] = 0;
1342 for(j = 0; j < id->pages_per_area; j++) {
1343 memset(id->areas[i][j], 0, PAGE_SIZE);
1344 }
1345 }
1346 } else if(area >= 0 && area < id->nr_areas) {
1347 id->active_entries[area] = 0;
1348 id->active_pages[area] = 0;
1349 for(i = 0; i < id->pages_per_area; i++) {
1350 memset(id->areas[area][i],0,PAGE_SIZE);
1351 }
1352 }
1353 spin_unlock_irqrestore(&id->lock,flags);
1354 }
1355
1356 /*
1357 * view function: flushes debug areas
1358 */
1359
1360 static int
1361 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1362 struct file *file, const char __user *user_buf,
1363 size_t user_len, loff_t * offset)
1364 {
1365 char input_buf[1];
1366 int rc = user_len;
1367
1368 if (user_len > 0x10000)
1369 user_len = 0x10000;
1370 if (*offset != 0){
1371 rc = -EPIPE;
1372 goto out;
1373 }
1374 if (copy_from_user(input_buf, user_buf, 1)){
1375 rc = -EFAULT;
1376 goto out;
1377 }
1378 if(input_buf[0] == '-') {
1379 debug_flush(id, DEBUG_FLUSH_ALL);
1380 goto out;
1381 }
1382 if (isdigit(input_buf[0])) {
1383 int area = ((int) input_buf[0] - (int) '0');
1384 debug_flush(id, area);
1385 goto out;
1386 }
1387
1388 pr_info("Flushing debug data failed because %c is not a valid "
1389 "area\n", input_buf[0]);
1390
1391 out:
1392 *offset += user_len;
1393 return rc; /* number of input characters */
1394 }
1395
1396 /*
1397 * prints debug header in raw format
1398 */
1399
1400 static int
1401 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1402 int area, debug_entry_t * entry, char *out_buf)
1403 {
1404 int rc;
1405
1406 rc = sizeof(debug_entry_t);
1407 memcpy(out_buf,entry,sizeof(debug_entry_t));
1408 return rc;
1409 }
1410
1411 /*
1412 * prints debug data in raw format
1413 */
1414
1415 static int
1416 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1417 char *out_buf, const char *in_buf)
1418 {
1419 int rc;
1420
1421 rc = id->buf_size;
1422 memcpy(out_buf, in_buf, id->buf_size);
1423 return rc;
1424 }
1425
1426 /*
1427 * prints debug data in hex/ascii format
1428 */
1429
1430 static int
1431 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1432 char *out_buf, const char *in_buf)
1433 {
1434 int i, rc = 0;
1435
1436 for (i = 0; i < id->buf_size; i++) {
1437 rc += sprintf(out_buf + rc, "%02x ",
1438 ((unsigned char *) in_buf)[i]);
1439 }
1440 rc += sprintf(out_buf + rc, "| ");
1441 for (i = 0; i < id->buf_size; i++) {
1442 unsigned char c = in_buf[i];
1443 if (isascii(c) && isprint(c))
1444 rc += sprintf(out_buf + rc, "%c", c);
1445 else
1446 rc += sprintf(out_buf + rc, ".");
1447 }
1448 rc += sprintf(out_buf + rc, "\n");
1449 return rc;
1450 }
1451
1452 /*
1453 * prints header for debug entry
1454 */
1455
1456 int
1457 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1458 int area, debug_entry_t * entry, char *out_buf)
1459 {
1460 struct timespec64 time_spec;
1461 char *except_str;
1462 unsigned long caller;
1463 int rc = 0;
1464 unsigned int level;
1465
1466 level = entry->id.fields.level;
1467 stck_to_timespec64(entry->id.stck, &time_spec);
1468
1469 if (entry->id.fields.exception)
1470 except_str = "*";
1471 else
1472 except_str = "-";
1473 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1474 rc += sprintf(out_buf, "%02i %011lld:%06lu %1u %1s %02i %p ",
1475 area, (long long)time_spec.tv_sec,
1476 time_spec.tv_nsec / 1000, level, except_str,
1477 entry->id.fields.cpuid, (void *)caller);
1478 return rc;
1479 }
1480 EXPORT_SYMBOL(debug_dflt_header_fn);
1481
1482 /*
1483 * prints debug data sprintf-formated:
1484 * debug_sprinf_event/exception calls must be used together with this view
1485 */
1486
1487 #define DEBUG_SPRINTF_MAX_ARGS 10
1488
1489 static int
1490 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1491 char *out_buf, debug_sprintf_entry_t *curr_event)
1492 {
1493 int num_longs, num_used_args = 0,i, rc = 0;
1494 int index[DEBUG_SPRINTF_MAX_ARGS];
1495
1496 /* count of longs fit into one entry */
1497 num_longs = id->buf_size / sizeof(long);
1498
1499 if(num_longs < 1)
1500 goto out; /* bufsize of entry too small */
1501 if(num_longs == 1) {
1502 /* no args, we use only the string */
1503 strcpy(out_buf, curr_event->string);
1504 rc = strlen(curr_event->string);
1505 goto out;
1506 }
1507
1508 /* number of arguments used for sprintf (without the format string) */
1509 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1510
1511 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1512
1513 for(i = 0; i < num_used_args; i++)
1514 index[i] = i;
1515
1516 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1517 curr_event->args[index[1]], curr_event->args[index[2]],
1518 curr_event->args[index[3]], curr_event->args[index[4]],
1519 curr_event->args[index[5]], curr_event->args[index[6]],
1520 curr_event->args[index[7]], curr_event->args[index[8]],
1521 curr_event->args[index[9]]);
1522
1523 out:
1524
1525 return rc;
1526 }
1527
1528 /*
1529 * debug_init:
1530 * - is called exactly once to initialize the debug feature
1531 */
1532 static int __init debug_init(void)
1533 {
1534 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1535 mutex_lock(&debug_mutex);
1536 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1537 initialized = 1;
1538 mutex_unlock(&debug_mutex);
1539 return 0;
1540 }
1541 postcore_initcall(debug_init);
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