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x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / arch / s390 / kernel / debug.c
blob05a9cf4ae9c2409c86fcbde39c37b26e0ef0693e
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2012
6 *
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 <linux/uaccess.h>
24 #include <linux/export.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 EXPORT_SYMBOL(debug_raw_view);
115
116 struct debug_view debug_hex_ascii_view = {
117 "hex_ascii",
118 NULL,
119 &debug_dflt_header_fn,
120 &debug_hex_ascii_format_fn,
121 NULL,
122 NULL
123 };
124 EXPORT_SYMBOL(debug_hex_ascii_view);
125
126 static struct debug_view debug_level_view = {
127 "level",
128 &debug_prolog_level_fn,
129 NULL,
130 NULL,
131 &debug_input_level_fn,
132 NULL
133 };
134
135 static struct debug_view debug_pages_view = {
136 "pages",
137 &debug_prolog_pages_fn,
138 NULL,
139 NULL,
140 &debug_input_pages_fn,
141 NULL
142 };
143
144 static struct debug_view debug_flush_view = {
145 "flush",
146 NULL,
147 NULL,
148 NULL,
149 &debug_input_flush_fn,
150 NULL
151 };
152
153 struct debug_view debug_sprintf_view = {
154 "sprintf",
155 NULL,
156 &debug_dflt_header_fn,
157 (debug_format_proc_t*)&debug_sprintf_format_fn,
158 NULL,
159 NULL
160 };
161 EXPORT_SYMBOL(debug_sprintf_view);
162
163 /* used by dump analysis tools to determine version of debug feature */
164 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
165
166 /* static globals */
167
168 static debug_info_t *debug_area_first = NULL;
169 static debug_info_t *debug_area_last = NULL;
170 static DEFINE_MUTEX(debug_mutex);
171
172 static int initialized;
173 static int debug_critical;
174
175 static const struct file_operations debug_file_ops = {
176 .owner = THIS_MODULE,
177 .read = debug_output,
178 .write = debug_input,
179 .open = debug_open,
180 .release = debug_close,
181 .llseek = no_llseek,
182 };
183
184 static struct dentry *debug_debugfs_root_entry;
185
186 /* functions */
187
188 /*
189 * debug_areas_alloc
190 * - Debug areas are implemented as a threedimensonal array:
191 * areas[areanumber][pagenumber][pageoffset]
192 */
193
194 static debug_entry_t***
195 debug_areas_alloc(int pages_per_area, int nr_areas)
196 {
197 debug_entry_t*** areas;
198 int i,j;
199
200 areas = kmalloc(nr_areas *
201 sizeof(debug_entry_t**),
202 GFP_KERNEL);
203 if (!areas)
204 goto fail_malloc_areas;
205 for (i = 0; i < nr_areas; i++) {
206 areas[i] = kmalloc(pages_per_area *
207 sizeof(debug_entry_t*),GFP_KERNEL);
208 if (!areas[i]) {
209 goto fail_malloc_areas2;
210 }
211 for(j = 0; j < pages_per_area; j++) {
212 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
213 if(!areas[i][j]) {
214 for(j--; j >=0 ; j--) {
215 kfree(areas[i][j]);
216 }
217 kfree(areas[i]);
218 goto fail_malloc_areas2;
219 }
220 }
221 }
222 return areas;
223
224 fail_malloc_areas2:
225 for(i--; i >= 0; i--){
226 for(j=0; j < pages_per_area;j++){
227 kfree(areas[i][j]);
228 }
229 kfree(areas[i]);
230 }
231 kfree(areas);
232 fail_malloc_areas:
233 return NULL;
234
235 }
236
237
238 /*
239 * debug_info_alloc
240 * - alloc new debug-info
241 */
242
243 static debug_info_t*
244 debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
245 int buf_size, int level, int mode)
246 {
247 debug_info_t* rc;
248
249 /* alloc everything */
250
251 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
252 if(!rc)
253 goto fail_malloc_rc;
254 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
255 if(!rc->active_entries)
256 goto fail_malloc_active_entries;
257 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
258 if(!rc->active_pages)
259 goto fail_malloc_active_pages;
260 if((mode == ALL_AREAS) && (pages_per_area != 0)){
261 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
262 if(!rc->areas)
263 goto fail_malloc_areas;
264 } else {
265 rc->areas = NULL;
266 }
267
268 /* initialize members */
269
270 spin_lock_init(&rc->lock);
271 rc->pages_per_area = pages_per_area;
272 rc->nr_areas = nr_areas;
273 rc->active_area = 0;
274 rc->level = level;
275 rc->buf_size = buf_size;
276 rc->entry_size = sizeof(debug_entry_t) + buf_size;
277 strlcpy(rc->name, name, sizeof(rc->name));
278 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
279 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
280 sizeof(struct dentry*));
281 refcount_set(&(rc->ref_count), 0);
282
283 return rc;
284
285 fail_malloc_areas:
286 kfree(rc->active_pages);
287 fail_malloc_active_pages:
288 kfree(rc->active_entries);
289 fail_malloc_active_entries:
290 kfree(rc);
291 fail_malloc_rc:
292 return NULL;
293 }
294
295 /*
296 * debug_areas_free
297 * - free all debug areas
298 */
299
300 static void
301 debug_areas_free(debug_info_t* db_info)
302 {
303 int i,j;
304
305 if(!db_info->areas)
306 return;
307 for (i = 0; i < db_info->nr_areas; i++) {
308 for(j = 0; j < db_info->pages_per_area; j++) {
309 kfree(db_info->areas[i][j]);
310 }
311 kfree(db_info->areas[i]);
312 }
313 kfree(db_info->areas);
314 db_info->areas = NULL;
315 }
316
317 /*
318 * debug_info_free
319 * - free memory debug-info
320 */
321
322 static void
323 debug_info_free(debug_info_t* db_info){
324 debug_areas_free(db_info);
325 kfree(db_info->active_entries);
326 kfree(db_info->active_pages);
327 kfree(db_info);
328 }
329
330 /*
331 * debug_info_create
332 * - create new debug-info
333 */
334
335 static debug_info_t*
336 debug_info_create(const char *name, int pages_per_area, int nr_areas,
337 int buf_size, umode_t mode)
338 {
339 debug_info_t* rc;
340
341 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
342 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
343 if(!rc)
344 goto out;
345
346 rc->mode = mode & ~S_IFMT;
347
348 /* create root directory */
349 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
350 debug_debugfs_root_entry);
351
352 /* append new element to linked list */
353 if (!debug_area_first) {
354 /* first element in list */
355 debug_area_first = rc;
356 rc->prev = NULL;
357 } else {
358 /* append element to end of list */
359 debug_area_last->next = rc;
360 rc->prev = debug_area_last;
361 }
362 debug_area_last = rc;
363 rc->next = NULL;
364
365 refcount_set(&rc->ref_count, 1);
366 out:
367 return rc;
368 }
369
370 /*
371 * debug_info_copy
372 * - copy debug-info
373 */
374
375 static debug_info_t*
376 debug_info_copy(debug_info_t* in, int mode)
377 {
378 int i,j;
379 debug_info_t* rc;
380 unsigned long flags;
381
382 /* get a consistent copy of the debug areas */
383 do {
384 rc = debug_info_alloc(in->name, in->pages_per_area,
385 in->nr_areas, in->buf_size, in->level, mode);
386 spin_lock_irqsave(&in->lock, flags);
387 if(!rc)
388 goto out;
389 /* has something changed in the meantime ? */
390 if((rc->pages_per_area == in->pages_per_area) &&
391 (rc->nr_areas == in->nr_areas)) {
392 break;
393 }
394 spin_unlock_irqrestore(&in->lock, flags);
395 debug_info_free(rc);
396 } while (1);
397
398 if (mode == NO_AREAS)
399 goto out;
400
401 for(i = 0; i < in->nr_areas; i++){
402 for(j = 0; j < in->pages_per_area; j++) {
403 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
404 }
405 }
406 out:
407 spin_unlock_irqrestore(&in->lock, flags);
408 return rc;
409 }
410
411 /*
412 * debug_info_get
413 * - increments reference count for debug-info
414 */
415
416 static void
417 debug_info_get(debug_info_t * db_info)
418 {
419 if (db_info)
420 refcount_inc(&db_info->ref_count);
421 }
422
423 /*
424 * debug_info_put:
425 * - decreases reference count for debug-info and frees it if necessary
426 */
427
428 static void
429 debug_info_put(debug_info_t *db_info)
430 {
431 int i;
432
433 if (!db_info)
434 return;
435 if (refcount_dec_and_test(&db_info->ref_count)) {
436 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
437 if (!db_info->views[i])
438 continue;
439 debugfs_remove(db_info->debugfs_entries[i]);
440 }
441 debugfs_remove(db_info->debugfs_root_entry);
442 if(db_info == debug_area_first)
443 debug_area_first = db_info->next;
444 if(db_info == debug_area_last)
445 debug_area_last = db_info->prev;
446 if(db_info->prev) db_info->prev->next = db_info->next;
447 if(db_info->next) db_info->next->prev = db_info->prev;
448 debug_info_free(db_info);
449 }
450 }
451
452 /*
453 * debug_format_entry:
454 * - format one debug entry and return size of formated data
455 */
456
457 static int
458 debug_format_entry(file_private_info_t *p_info)
459 {
460 debug_info_t *id_snap = p_info->debug_info_snap;
461 struct debug_view *view = p_info->view;
462 debug_entry_t *act_entry;
463 size_t len = 0;
464 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
465 /* print prolog */
466 if (view->prolog_proc)
467 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
468 goto out;
469 }
470 if (!id_snap->areas) /* this is true, if we have a prolog only view */
471 goto out; /* or if 'pages_per_area' is 0 */
472 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
473 [p_info->act_page] + p_info->act_entry);
474
475 if (act_entry->id.stck == 0LL)
476 goto out; /* empty entry */
477 if (view->header_proc)
478 len += view->header_proc(id_snap, view, p_info->act_area,
479 act_entry, p_info->temp_buf + len);
480 if (view->format_proc)
481 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
482 DEBUG_DATA(act_entry));
483 out:
484 return len;
485 }
486
487 /*
488 * debug_next_entry:
489 * - goto next entry in p_info
490 */
491
492 static inline int
493 debug_next_entry(file_private_info_t *p_info)
494 {
495 debug_info_t *id;
496
497 id = p_info->debug_info_snap;
498 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
499 p_info->act_entry = 0;
500 p_info->act_page = 0;
501 goto out;
502 }
503 if(!id->areas)
504 return 1;
505 p_info->act_entry += id->entry_size;
506 /* switch to next page, if we reached the end of the page */
507 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
508 /* next page */
509 p_info->act_entry = 0;
510 p_info->act_page += 1;
511 if((p_info->act_page % id->pages_per_area) == 0) {
512 /* next area */
513 p_info->act_area++;
514 p_info->act_page=0;
515 }
516 if(p_info->act_area >= id->nr_areas)
517 return 1;
518 }
519 out:
520 return 0;
521 }
522
523 /*
524 * debug_output:
525 * - called for user read()
526 * - copies formated debug entries to the user buffer
527 */
528
529 static ssize_t
530 debug_output(struct file *file, /* file descriptor */
531 char __user *user_buf, /* user buffer */
532 size_t len, /* length of buffer */
533 loff_t *offset) /* offset in the file */
534 {
535 size_t count = 0;
536 size_t entry_offset;
537 file_private_info_t *p_info;
538
539 p_info = ((file_private_info_t *) file->private_data);
540 if (*offset != p_info->offset)
541 return -EPIPE;
542 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
543 return 0;
544 entry_offset = p_info->act_entry_offset;
545 while(count < len){
546 int formatted_line_size;
547 int formatted_line_residue;
548 int user_buf_residue;
549 size_t copy_size;
550
551 formatted_line_size = debug_format_entry(p_info);
552 formatted_line_residue = formatted_line_size - entry_offset;
553 user_buf_residue = len-count;
554 copy_size = min(user_buf_residue, formatted_line_residue);
555 if(copy_size){
556 if (copy_to_user(user_buf + count, p_info->temp_buf
557 + entry_offset, copy_size))
558 return -EFAULT;
559 count += copy_size;
560 entry_offset += copy_size;
561 }
562 if(copy_size == formatted_line_residue){
563 entry_offset = 0;
564 if(debug_next_entry(p_info))
565 goto out;
566 }
567 }
568 out:
569 p_info->offset = *offset + count;
570 p_info->act_entry_offset = entry_offset;
571 *offset = p_info->offset;
572 return count;
573 }
574
575 /*
576 * debug_input:
577 * - called for user write()
578 * - calls input function of view
579 */
580
581 static ssize_t
582 debug_input(struct file *file, const char __user *user_buf, size_t length,
583 loff_t *offset)
584 {
585 int rc = 0;
586 file_private_info_t *p_info;
587
588 mutex_lock(&debug_mutex);
589 p_info = ((file_private_info_t *) file->private_data);
590 if (p_info->view->input_proc)
591 rc = p_info->view->input_proc(p_info->debug_info_org,
592 p_info->view, file, user_buf,
593 length, offset);
594 else
595 rc = -EPERM;
596 mutex_unlock(&debug_mutex);
597 return rc; /* number of input characters */
598 }
599
600 /*
601 * debug_open:
602 * - called for user open()
603 * - copies formated output to private_data area of the file
604 * handle
605 */
606
607 static int
608 debug_open(struct inode *inode, struct file *file)
609 {
610 int i, rc = 0;
611 file_private_info_t *p_info;
612 debug_info_t *debug_info, *debug_info_snapshot;
613
614 mutex_lock(&debug_mutex);
615 debug_info = file_inode(file)->i_private;
616 /* find debug view */
617 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
618 if (!debug_info->views[i])
619 continue;
620 else if (debug_info->debugfs_entries[i] ==
621 file->f_path.dentry) {
622 goto found; /* found view ! */
623 }
624 }
625 /* no entry found */
626 rc = -EINVAL;
627 goto out;
628
629 found:
630
631 /* Make snapshot of current debug areas to get it consistent. */
632 /* To copy all the areas is only needed, if we have a view which */
633 /* formats the debug areas. */
634
635 if(!debug_info->views[i]->format_proc &&
636 !debug_info->views[i]->header_proc){
637 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
638 } else {
639 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
640 }
641
642 if(!debug_info_snapshot){
643 rc = -ENOMEM;
644 goto out;
645 }
646 p_info = kmalloc(sizeof(file_private_info_t),
647 GFP_KERNEL);
648 if(!p_info){
649 debug_info_free(debug_info_snapshot);
650 rc = -ENOMEM;
651 goto out;
652 }
653 p_info->offset = 0;
654 p_info->debug_info_snap = debug_info_snapshot;
655 p_info->debug_info_org = debug_info;
656 p_info->view = debug_info->views[i];
657 p_info->act_area = 0;
658 p_info->act_page = 0;
659 p_info->act_entry = DEBUG_PROLOG_ENTRY;
660 p_info->act_entry_offset = 0;
661 file->private_data = p_info;
662 debug_info_get(debug_info);
663 nonseekable_open(inode, file);
664 out:
665 mutex_unlock(&debug_mutex);
666 return rc;
667 }
668
669 /*
670 * debug_close:
671 * - called for user close()
672 * - deletes private_data area of the file handle
673 */
674
675 static int
676 debug_close(struct inode *inode, struct file *file)
677 {
678 file_private_info_t *p_info;
679 p_info = (file_private_info_t *) file->private_data;
680 if(p_info->debug_info_snap)
681 debug_info_free(p_info->debug_info_snap);
682 debug_info_put(p_info->debug_info_org);
683 kfree(file->private_data);
684 return 0; /* success */
685 }
686
687 /*
688 * debug_register_mode:
689 * - Creates and initializes debug area for the caller
690 * The mode parameter allows to specify access rights for the s390dbf files
691 * - Returns handle for debug area
692 */
693
694 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
695 int nr_areas, int buf_size, umode_t mode,
696 uid_t uid, gid_t gid)
697 {
698 debug_info_t *rc = NULL;
699
700 /* Since debugfs currently does not support uid/gid other than root, */
701 /* we do not allow gid/uid != 0 until we get support for that. */
702 if ((uid != 0) || (gid != 0))
703 pr_warn("Root becomes the owner of all s390dbf files 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 *(unsigned long long *) &tod_clock_base[1];
872 active->id.fields.cpuid = smp_processor_id();
873 active->caller = __builtin_return_address(0);
874 active->id.fields.exception = exception;
875 active->id.fields.level = level;
876 proceed_active_entry(id);
877 if(exception)
878 proceed_active_area(id);
879 }
880
881 static int debug_stoppable=1;
882 static int debug_active=1;
883
884 #define CTL_S390DBF_STOPPABLE 5678
885 #define CTL_S390DBF_ACTIVE 5679
886
887 /*
888 * proc handler for the running debug_active sysctl
889 * always allow read, allow write only if debug_stoppable is set or
890 * if debug_active is already off
891 */
892 static int
893 s390dbf_procactive(struct ctl_table *table, int write,
894 void __user *buffer, size_t *lenp, loff_t *ppos)
895 {
896 if (!write || debug_stoppable || !debug_active)
897 return proc_dointvec(table, write, buffer, lenp, ppos);
898 else
899 return 0;
900 }
901
902
903 static struct ctl_table s390dbf_table[] = {
904 {
905 .procname = "debug_stoppable",
906 .data = &debug_stoppable,
907 .maxlen = sizeof(int),
908 .mode = S_IRUGO | S_IWUSR,
909 .proc_handler = proc_dointvec,
910 },
911 {
912 .procname = "debug_active",
913 .data = &debug_active,
914 .maxlen = sizeof(int),
915 .mode = S_IRUGO | S_IWUSR,
916 .proc_handler = s390dbf_procactive,
917 },
918 { }
919 };
920
921 static struct ctl_table s390dbf_dir_table[] = {
922 {
923 .procname = "s390dbf",
924 .maxlen = 0,
925 .mode = S_IRUGO | S_IXUGO,
926 .child = s390dbf_table,
927 },
928 { }
929 };
930
931 static struct ctl_table_header *s390dbf_sysctl_header;
932
933 void
934 debug_stop_all(void)
935 {
936 if (debug_stoppable)
937 debug_active = 0;
938 }
939 EXPORT_SYMBOL(debug_stop_all);
940
941 void debug_set_critical(void)
942 {
943 debug_critical = 1;
944 }
945
946 /*
947 * debug_event_common:
948 * - write debug entry with given size
949 */
950
951 debug_entry_t*
952 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
953 {
954 unsigned long flags;
955 debug_entry_t *active;
956
957 if (!debug_active || !id->areas)
958 return NULL;
959 if (debug_critical) {
960 if (!spin_trylock_irqsave(&id->lock, flags))
961 return NULL;
962 } else
963 spin_lock_irqsave(&id->lock, flags);
964 active = get_active_entry(id);
965 memset(DEBUG_DATA(active), 0, id->buf_size);
966 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
967 debug_finish_entry(id, active, level, 0);
968 spin_unlock_irqrestore(&id->lock, flags);
969
970 return active;
971 }
972 EXPORT_SYMBOL(debug_event_common);
973
974 /*
975 * debug_exception_common:
976 * - write debug entry with given size and switch to next debug area
977 */
978
979 debug_entry_t
980 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
981 {
982 unsigned long flags;
983 debug_entry_t *active;
984
985 if (!debug_active || !id->areas)
986 return NULL;
987 if (debug_critical) {
988 if (!spin_trylock_irqsave(&id->lock, flags))
989 return NULL;
990 } else
991 spin_lock_irqsave(&id->lock, flags);
992 active = get_active_entry(id);
993 memset(DEBUG_DATA(active), 0, id->buf_size);
994 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
995 debug_finish_entry(id, active, level, 1);
996 spin_unlock_irqrestore(&id->lock, flags);
997
998 return active;
999 }
1000 EXPORT_SYMBOL(debug_exception_common);
1001
1002 /*
1003 * counts arguments in format string for sprintf view
1004 */
1005
1006 static inline int
1007 debug_count_numargs(char *string)
1008 {
1009 int numargs=0;
1010
1011 while(*string) {
1012 if(*string++=='%')
1013 numargs++;
1014 }
1015 return(numargs);
1016 }
1017
1018 /*
1019 * debug_sprintf_event:
1020 */
1021
1022 debug_entry_t*
1023 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1024 {
1025 va_list ap;
1026 int numargs,idx;
1027 unsigned long flags;
1028 debug_sprintf_entry_t *curr_event;
1029 debug_entry_t *active;
1030
1031 if (!debug_active || !id->areas)
1032 return NULL;
1033 numargs=debug_count_numargs(string);
1034
1035 if (debug_critical) {
1036 if (!spin_trylock_irqsave(&id->lock, flags))
1037 return NULL;
1038 } else
1039 spin_lock_irqsave(&id->lock, flags);
1040 active = get_active_entry(id);
1041 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1042 va_start(ap,string);
1043 curr_event->string=string;
1044 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1045 curr_event->args[idx]=va_arg(ap,long);
1046 va_end(ap);
1047 debug_finish_entry(id, active, level, 0);
1048 spin_unlock_irqrestore(&id->lock, flags);
1049
1050 return active;
1051 }
1052 EXPORT_SYMBOL(__debug_sprintf_event);
1053
1054 /*
1055 * debug_sprintf_exception:
1056 */
1057
1058 debug_entry_t*
1059 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1060 {
1061 va_list ap;
1062 int numargs,idx;
1063 unsigned long flags;
1064 debug_sprintf_entry_t *curr_event;
1065 debug_entry_t *active;
1066
1067 if (!debug_active || !id->areas)
1068 return NULL;
1069
1070 numargs=debug_count_numargs(string);
1071
1072 if (debug_critical) {
1073 if (!spin_trylock_irqsave(&id->lock, flags))
1074 return NULL;
1075 } else
1076 spin_lock_irqsave(&id->lock, flags);
1077 active = get_active_entry(id);
1078 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1079 va_start(ap,string);
1080 curr_event->string=string;
1081 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1082 curr_event->args[idx]=va_arg(ap,long);
1083 va_end(ap);
1084 debug_finish_entry(id, active, level, 1);
1085 spin_unlock_irqrestore(&id->lock, flags);
1086
1087 return active;
1088 }
1089 EXPORT_SYMBOL(__debug_sprintf_exception);
1090
1091 /*
1092 * debug_register_view:
1093 */
1094
1095 int
1096 debug_register_view(debug_info_t * id, struct debug_view *view)
1097 {
1098 int rc = 0;
1099 int i;
1100 unsigned long flags;
1101 umode_t mode;
1102 struct dentry *pde;
1103
1104 if (!id)
1105 goto out;
1106 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1107 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1108 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1109 if (!view->input_proc)
1110 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1111 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1112 id , &debug_file_ops);
1113 if (!pde){
1114 pr_err("Registering view %s/%s failed due to out of "
1115 "memory\n", id->name,view->name);
1116 rc = -1;
1117 goto out;
1118 }
1119 spin_lock_irqsave(&id->lock, flags);
1120 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1121 if (!id->views[i])
1122 break;
1123 }
1124 if (i == DEBUG_MAX_VIEWS) {
1125 pr_err("Registering view %s/%s would exceed the maximum "
1126 "number of views %i\n", id->name, view->name, i);
1127 rc = -1;
1128 } else {
1129 id->views[i] = view;
1130 id->debugfs_entries[i] = pde;
1131 }
1132 spin_unlock_irqrestore(&id->lock, flags);
1133 if (rc)
1134 debugfs_remove(pde);
1135 out:
1136 return rc;
1137 }
1138 EXPORT_SYMBOL(debug_register_view);
1139
1140 /*
1141 * debug_unregister_view:
1142 */
1143
1144 int
1145 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1146 {
1147 struct dentry *dentry = NULL;
1148 unsigned long flags;
1149 int i, rc = 0;
1150
1151 if (!id)
1152 goto out;
1153 spin_lock_irqsave(&id->lock, flags);
1154 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1155 if (id->views[i] == view)
1156 break;
1157 }
1158 if (i == DEBUG_MAX_VIEWS)
1159 rc = -1;
1160 else {
1161 dentry = id->debugfs_entries[i];
1162 id->views[i] = NULL;
1163 id->debugfs_entries[i] = NULL;
1164 }
1165 spin_unlock_irqrestore(&id->lock, flags);
1166 debugfs_remove(dentry);
1167 out:
1168 return rc;
1169 }
1170 EXPORT_SYMBOL(debug_unregister_view);
1171
1172 static inline char *
1173 debug_get_user_string(const char __user *user_buf, size_t user_len)
1174 {
1175 char* buffer;
1176
1177 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1178 if (!buffer)
1179 return ERR_PTR(-ENOMEM);
1180 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1181 kfree(buffer);
1182 return ERR_PTR(-EFAULT);
1183 }
1184 /* got the string, now strip linefeed. */
1185 if (buffer[user_len - 1] == '\n')
1186 buffer[user_len - 1] = 0;
1187 else
1188 buffer[user_len] = 0;
1189 return buffer;
1190 }
1191
1192 static inline int
1193 debug_get_uint(char *buf)
1194 {
1195 int rc;
1196
1197 buf = skip_spaces(buf);
1198 rc = simple_strtoul(buf, &buf, 10);
1199 if(*buf){
1200 rc = -EINVAL;
1201 }
1202 return rc;
1203 }
1204
1205 /*
1206 * functions for debug-views
1207 ***********************************
1208 */
1209
1210 /*
1211 * prints out actual debug level
1212 */
1213
1214 static int
1215 debug_prolog_pages_fn(debug_info_t * id,
1216 struct debug_view *view, char *out_buf)
1217 {
1218 return sprintf(out_buf, "%i\n", id->pages_per_area);
1219 }
1220
1221 /*
1222 * reads new size (number of pages per debug area)
1223 */
1224
1225 static int
1226 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1227 struct file *file, const char __user *user_buf,
1228 size_t user_len, loff_t * offset)
1229 {
1230 char *str;
1231 int rc,new_pages;
1232
1233 if (user_len > 0x10000)
1234 user_len = 0x10000;
1235 if (*offset != 0){
1236 rc = -EPIPE;
1237 goto out;
1238 }
1239 str = debug_get_user_string(user_buf,user_len);
1240 if(IS_ERR(str)){
1241 rc = PTR_ERR(str);
1242 goto out;
1243 }
1244 new_pages = debug_get_uint(str);
1245 if(new_pages < 0){
1246 rc = -EINVAL;
1247 goto free_str;
1248 }
1249 rc = debug_set_size(id,id->nr_areas, new_pages);
1250 if(rc != 0){
1251 rc = -EINVAL;
1252 goto free_str;
1253 }
1254 rc = user_len;
1255 free_str:
1256 kfree(str);
1257 out:
1258 *offset += user_len;
1259 return rc; /* number of input characters */
1260 }
1261
1262 /*
1263 * prints out actual debug level
1264 */
1265
1266 static int
1267 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1268 {
1269 int rc = 0;
1270
1271 if(id->level == DEBUG_OFF_LEVEL) {
1272 rc = sprintf(out_buf,"-\n");
1273 }
1274 else {
1275 rc = sprintf(out_buf, "%i\n", id->level);
1276 }
1277 return rc;
1278 }
1279
1280 /*
1281 * reads new debug level
1282 */
1283
1284 static int
1285 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1286 struct file *file, const char __user *user_buf,
1287 size_t user_len, loff_t * offset)
1288 {
1289 char *str;
1290 int rc,new_level;
1291
1292 if (user_len > 0x10000)
1293 user_len = 0x10000;
1294 if (*offset != 0){
1295 rc = -EPIPE;
1296 goto out;
1297 }
1298 str = debug_get_user_string(user_buf,user_len);
1299 if(IS_ERR(str)){
1300 rc = PTR_ERR(str);
1301 goto out;
1302 }
1303 if(str[0] == '-'){
1304 debug_set_level(id, DEBUG_OFF_LEVEL);
1305 rc = user_len;
1306 goto free_str;
1307 } else {
1308 new_level = debug_get_uint(str);
1309 }
1310 if(new_level < 0) {
1311 pr_warn("%s is not a valid level for a debug 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 unsigned long base, sec, usec;
1461 char *except_str;
1462 unsigned long caller;
1463 int rc = 0;
1464 unsigned int level;
1465
1466 level = entry->id.fields.level;
1467 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1468 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1469 usec = do_div(sec, USEC_PER_SEC);
1470
1471 if (entry->id.fields.exception)
1472 except_str = "*";
1473 else
1474 except_str = "-";
1475 caller = (unsigned long) entry->caller;
1476 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %p ",
1477 area, sec, usec, level, except_str,
1478 entry->id.fields.cpuid, (void *)caller);
1479 return rc;
1480 }
1481 EXPORT_SYMBOL(debug_dflt_header_fn);
1482
1483 /*
1484 * prints debug data sprintf-formated:
1485 * debug_sprinf_event/exception calls must be used together with this view
1486 */
1487
1488 #define DEBUG_SPRINTF_MAX_ARGS 10
1489
1490 static int
1491 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1492 char *out_buf, debug_sprintf_entry_t *curr_event)
1493 {
1494 int num_longs, num_used_args = 0,i, rc = 0;
1495 int index[DEBUG_SPRINTF_MAX_ARGS];
1496
1497 /* count of longs fit into one entry */
1498 num_longs = id->buf_size / sizeof(long);
1499
1500 if(num_longs < 1)
1501 goto out; /* bufsize of entry too small */
1502 if(num_longs == 1) {
1503 /* no args, we use only the string */
1504 strcpy(out_buf, curr_event->string);
1505 rc = strlen(curr_event->string);
1506 goto out;
1507 }
1508
1509 /* number of arguments used for sprintf (without the format string) */
1510 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1511
1512 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1513
1514 for(i = 0; i < num_used_args; i++)
1515 index[i] = i;
1516
1517 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1518 curr_event->args[index[1]], curr_event->args[index[2]],
1519 curr_event->args[index[3]], curr_event->args[index[4]],
1520 curr_event->args[index[5]], curr_event->args[index[6]],
1521 curr_event->args[index[7]], curr_event->args[index[8]],
1522 curr_event->args[index[9]]);
1523
1524 out:
1525
1526 return rc;
1527 }
1528
1529 /*
1530 * debug_init:
1531 * - is called exactly once to initialize the debug feature
1532 */
1533 static int __init debug_init(void)
1534 {
1535 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1536 mutex_lock(&debug_mutex);
1537 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1538 initialized = 1;
1539 mutex_unlock(&debug_mutex);
1540 return 0;
1541 }
1542 postcore_initcall(debug_init);
Linux with added FPC-III support