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[linux/fpc-iii.git] / arch / s390 / kernel / debug.c
blob0ebf08c3b35ebd658f38322834c46e0b7bf35813
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 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 /* internal function prototyes */
66
67 static int debug_init(void);
68 static ssize_t debug_output(struct file *file, char __user *user_buf,
69 size_t user_len, loff_t *offset);
70 static ssize_t debug_input(struct file *file, const char __user *user_buf,
71 size_t user_len, loff_t *offset);
72 static int debug_open(struct inode *inode, struct file *file);
73 static int debug_close(struct inode *inode, struct file *file);
74 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
75 int nr_areas, int buf_size, umode_t mode);
76 static void debug_info_get(debug_info_t *);
77 static void debug_info_put(debug_info_t *);
78 static int debug_prolog_level_fn(debug_info_t *id,
79 struct debug_view *view, char *out_buf);
80 static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
81 struct file *file, const char __user *user_buf,
82 size_t user_buf_size, loff_t *offset);
83 static int debug_prolog_pages_fn(debug_info_t *id,
84 struct debug_view *view, char *out_buf);
85 static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
86 struct file *file, const char __user *user_buf,
87 size_t user_buf_size, loff_t *offset);
88 static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
89 struct file *file, const char __user *user_buf,
90 size_t user_buf_size, loff_t *offset);
91 static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
92 char *out_buf, const char *in_buf);
93 static int debug_raw_format_fn(debug_info_t *id,
94 struct debug_view *view, char *out_buf,
95 const char *in_buf);
96 static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
97 int area, debug_entry_t *entry, char *out_buf);
98
99 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
100 char *out_buf, debug_sprintf_entry_t *curr_event);
101
102 /* globals */
103
104 struct debug_view debug_raw_view = {
105 "raw",
106 NULL,
107 &debug_raw_header_fn,
108 &debug_raw_format_fn,
109 NULL,
110 NULL
111 };
112 EXPORT_SYMBOL(debug_raw_view);
113
114 struct debug_view debug_hex_ascii_view = {
115 "hex_ascii",
116 NULL,
117 &debug_dflt_header_fn,
118 &debug_hex_ascii_format_fn,
119 NULL,
120 NULL
121 };
122 EXPORT_SYMBOL(debug_hex_ascii_view);
123
124 static struct debug_view debug_level_view = {
125 "level",
126 &debug_prolog_level_fn,
127 NULL,
128 NULL,
129 &debug_input_level_fn,
130 NULL
131 };
132
133 static struct debug_view debug_pages_view = {
134 "pages",
135 &debug_prolog_pages_fn,
136 NULL,
137 NULL,
138 &debug_input_pages_fn,
139 NULL
140 };
141
142 static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149 };
150
151 struct debug_view debug_sprintf_view = {
152 "sprintf",
153 NULL,
154 &debug_dflt_header_fn,
155 (debug_format_proc_t *)&debug_sprintf_format_fn,
156 NULL,
157 NULL
158 };
159 EXPORT_SYMBOL(debug_sprintf_view);
160
161 /* used by dump analysis tools to determine version of debug feature */
162 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
163
164 /* static globals */
165
166 static debug_info_t *debug_area_first;
167 static debug_info_t *debug_area_last;
168 static DEFINE_MUTEX(debug_mutex);
169
170 static int initialized;
171 static int debug_critical;
172
173 static const struct file_operations debug_file_ops = {
174 .owner = THIS_MODULE,
175 .read = debug_output,
176 .write = debug_input,
177 .open = debug_open,
178 .release = debug_close,
179 .llseek = no_llseek,
180 };
181
182 static struct dentry *debug_debugfs_root_entry;
183
184 /* functions */
185
186 /*
187 * debug_areas_alloc
188 * - Debug areas are implemented as a threedimensonal array:
189 * areas[areanumber][pagenumber][pageoffset]
190 */
191
192 static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
193 {
194 debug_entry_t ***areas;
195 int i, j;
196
197 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL);
198 if (!areas)
199 goto fail_malloc_areas;
200 for (i = 0; i < nr_areas; i++) {
201 areas[i] = kmalloc_array(pages_per_area,
202 sizeof(debug_entry_t *),
203 GFP_KERNEL);
204 if (!areas[i])
205 goto fail_malloc_areas2;
206 for (j = 0; j < pages_per_area; j++) {
207 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
208 if (!areas[i][j]) {
209 for (j--; j >= 0 ; j--)
210 kfree(areas[i][j]);
211 kfree(areas[i]);
212 goto fail_malloc_areas2;
213 }
214 }
215 }
216 return areas;
217
218 fail_malloc_areas2:
219 for (i--; i >= 0; i--) {
220 for (j = 0; j < pages_per_area; j++)
221 kfree(areas[i][j]);
222 kfree(areas[i]);
223 }
224 kfree(areas);
225 fail_malloc_areas:
226 return NULL;
227 }
228
229 /*
230 * debug_info_alloc
231 * - alloc new debug-info
232 */
233 static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
234 int nr_areas, int buf_size, int level,
235 int mode)
236 {
237 debug_info_t *rc;
238
239 /* alloc everything */
240 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
241 if (!rc)
242 goto fail_malloc_rc;
243 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
244 if (!rc->active_entries)
245 goto fail_malloc_active_entries;
246 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
247 if (!rc->active_pages)
248 goto fail_malloc_active_pages;
249 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
250 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
251 if (!rc->areas)
252 goto fail_malloc_areas;
253 } else {
254 rc->areas = NULL;
255 }
256
257 /* initialize members */
258 spin_lock_init(&rc->lock);
259 rc->pages_per_area = pages_per_area;
260 rc->nr_areas = nr_areas;
261 rc->active_area = 0;
262 rc->level = level;
263 rc->buf_size = buf_size;
264 rc->entry_size = sizeof(debug_entry_t) + buf_size;
265 strlcpy(rc->name, name, sizeof(rc->name));
266 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
267 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
268 refcount_set(&(rc->ref_count), 0);
269
270 return rc;
271
272 fail_malloc_areas:
273 kfree(rc->active_pages);
274 fail_malloc_active_pages:
275 kfree(rc->active_entries);
276 fail_malloc_active_entries:
277 kfree(rc);
278 fail_malloc_rc:
279 return NULL;
280 }
281
282 /*
283 * debug_areas_free
284 * - free all debug areas
285 */
286 static void debug_areas_free(debug_info_t *db_info)
287 {
288 int i, j;
289
290 if (!db_info->areas)
291 return;
292 for (i = 0; i < db_info->nr_areas; i++) {
293 for (j = 0; j < db_info->pages_per_area; j++)
294 kfree(db_info->areas[i][j]);
295 kfree(db_info->areas[i]);
296 }
297 kfree(db_info->areas);
298 db_info->areas = NULL;
299 }
300
301 /*
302 * debug_info_free
303 * - free memory debug-info
304 */
305 static void debug_info_free(debug_info_t *db_info)
306 {
307 debug_areas_free(db_info);
308 kfree(db_info->active_entries);
309 kfree(db_info->active_pages);
310 kfree(db_info);
311 }
312
313 /*
314 * debug_info_create
315 * - create new debug-info
316 */
317
318 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
319 int nr_areas, int buf_size, umode_t mode)
320 {
321 debug_info_t *rc;
322
323 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
324 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
325 if (!rc)
326 goto out;
327
328 rc->mode = mode & ~S_IFMT;
329
330 /* create root directory */
331 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
332 debug_debugfs_root_entry);
333
334 /* append new element to linked list */
335 if (!debug_area_first) {
336 /* first element in list */
337 debug_area_first = rc;
338 rc->prev = NULL;
339 } else {
340 /* append element to end of list */
341 debug_area_last->next = rc;
342 rc->prev = debug_area_last;
343 }
344 debug_area_last = rc;
345 rc->next = NULL;
346
347 refcount_set(&rc->ref_count, 1);
348 out:
349 return rc;
350 }
351
352 /*
353 * debug_info_copy
354 * - copy debug-info
355 */
356 static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
357 {
358 unsigned long flags;
359 debug_info_t *rc;
360 int i, j;
361
362 /* get a consistent copy of the debug areas */
363 do {
364 rc = debug_info_alloc(in->name, in->pages_per_area,
365 in->nr_areas, in->buf_size, in->level, mode);
366 spin_lock_irqsave(&in->lock, flags);
367 if (!rc)
368 goto out;
369 /* has something changed in the meantime ? */
370 if ((rc->pages_per_area == in->pages_per_area) &&
371 (rc->nr_areas == in->nr_areas)) {
372 break;
373 }
374 spin_unlock_irqrestore(&in->lock, flags);
375 debug_info_free(rc);
376 } while (1);
377
378 if (mode == NO_AREAS)
379 goto out;
380
381 for (i = 0; i < in->nr_areas; i++) {
382 for (j = 0; j < in->pages_per_area; j++)
383 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
384 }
385 out:
386 spin_unlock_irqrestore(&in->lock, flags);
387 return rc;
388 }
389
390 /*
391 * debug_info_get
392 * - increments reference count for debug-info
393 */
394 static void debug_info_get(debug_info_t *db_info)
395 {
396 if (db_info)
397 refcount_inc(&db_info->ref_count);
398 }
399
400 /*
401 * debug_info_put:
402 * - decreases reference count for debug-info and frees it if necessary
403 */
404 static void debug_info_put(debug_info_t *db_info)
405 {
406 int i;
407
408 if (!db_info)
409 return;
410 if (refcount_dec_and_test(&db_info->ref_count)) {
411 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
412 if (!db_info->views[i])
413 continue;
414 debugfs_remove(db_info->debugfs_entries[i]);
415 }
416 debugfs_remove(db_info->debugfs_root_entry);
417 if (db_info == debug_area_first)
418 debug_area_first = db_info->next;
419 if (db_info == debug_area_last)
420 debug_area_last = db_info->prev;
421 if (db_info->prev)
422 db_info->prev->next = db_info->next;
423 if (db_info->next)
424 db_info->next->prev = db_info->prev;
425 debug_info_free(db_info);
426 }
427 }
428
429 /*
430 * debug_format_entry:
431 * - format one debug entry and return size of formated data
432 */
433 static int debug_format_entry(file_private_info_t *p_info)
434 {
435 debug_info_t *id_snap = p_info->debug_info_snap;
436 struct debug_view *view = p_info->view;
437 debug_entry_t *act_entry;
438 size_t len = 0;
439
440 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
441 /* print prolog */
442 if (view->prolog_proc)
443 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
444 goto out;
445 }
446 if (!id_snap->areas) /* this is true, if we have a prolog only view */
447 goto out; /* or if 'pages_per_area' is 0 */
448 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
449 [p_info->act_page] + p_info->act_entry);
450
451 if (act_entry->id.stck == 0LL)
452 goto out; /* empty entry */
453 if (view->header_proc)
454 len += view->header_proc(id_snap, view, p_info->act_area,
455 act_entry, p_info->temp_buf + len);
456 if (view->format_proc)
457 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
458 DEBUG_DATA(act_entry));
459 out:
460 return len;
461 }
462
463 /*
464 * debug_next_entry:
465 * - goto next entry in p_info
466 */
467 static inline int debug_next_entry(file_private_info_t *p_info)
468 {
469 debug_info_t *id;
470
471 id = p_info->debug_info_snap;
472 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
473 p_info->act_entry = 0;
474 p_info->act_page = 0;
475 goto out;
476 }
477 if (!id->areas)
478 return 1;
479 p_info->act_entry += id->entry_size;
480 /* switch to next page, if we reached the end of the page */
481 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
482 /* next page */
483 p_info->act_entry = 0;
484 p_info->act_page += 1;
485 if ((p_info->act_page % id->pages_per_area) == 0) {
486 /* next area */
487 p_info->act_area++;
488 p_info->act_page = 0;
489 }
490 if (p_info->act_area >= id->nr_areas)
491 return 1;
492 }
493 out:
494 return 0;
495 }
496
497 /*
498 * debug_output:
499 * - called for user read()
500 * - copies formated debug entries to the user buffer
501 */
502 static ssize_t debug_output(struct file *file, /* file descriptor */
503 char __user *user_buf, /* user buffer */
504 size_t len, /* length of buffer */
505 loff_t *offset) /* offset in the file */
506 {
507 size_t count = 0;
508 size_t entry_offset;
509 file_private_info_t *p_info;
510
511 p_info = (file_private_info_t *) file->private_data;
512 if (*offset != p_info->offset)
513 return -EPIPE;
514 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
515 return 0;
516 entry_offset = p_info->act_entry_offset;
517 while (count < len) {
518 int formatted_line_residue;
519 int formatted_line_size;
520 int user_buf_residue;
521 size_t copy_size;
522
523 formatted_line_size = debug_format_entry(p_info);
524 formatted_line_residue = formatted_line_size - entry_offset;
525 user_buf_residue = len-count;
526 copy_size = min(user_buf_residue, formatted_line_residue);
527 if (copy_size) {
528 if (copy_to_user(user_buf + count, p_info->temp_buf
529 + entry_offset, copy_size))
530 return -EFAULT;
531 count += copy_size;
532 entry_offset += copy_size;
533 }
534 if (copy_size == formatted_line_residue) {
535 entry_offset = 0;
536 if (debug_next_entry(p_info))
537 goto out;
538 }
539 }
540 out:
541 p_info->offset = *offset + count;
542 p_info->act_entry_offset = entry_offset;
543 *offset = p_info->offset;
544 return count;
545 }
546
547 /*
548 * debug_input:
549 * - called for user write()
550 * - calls input function of view
551 */
552 static ssize_t debug_input(struct file *file, const char __user *user_buf,
553 size_t length, loff_t *offset)
554 {
555 file_private_info_t *p_info;
556 int rc = 0;
557
558 mutex_lock(&debug_mutex);
559 p_info = ((file_private_info_t *) file->private_data);
560 if (p_info->view->input_proc) {
561 rc = p_info->view->input_proc(p_info->debug_info_org,
562 p_info->view, file, user_buf,
563 length, offset);
564 } else {
565 rc = -EPERM;
566 }
567 mutex_unlock(&debug_mutex);
568 return rc; /* number of input characters */
569 }
570
571 /*
572 * debug_open:
573 * - called for user open()
574 * - copies formated output to private_data area of the file
575 * handle
576 */
577 static int debug_open(struct inode *inode, struct file *file)
578 {
579 debug_info_t *debug_info, *debug_info_snapshot;
580 file_private_info_t *p_info;
581 int i, rc = 0;
582
583 mutex_lock(&debug_mutex);
584 debug_info = file_inode(file)->i_private;
585 /* find debug view */
586 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
587 if (!debug_info->views[i])
588 continue;
589 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
590 goto found; /* found view ! */
591 }
592 /* no entry found */
593 rc = -EINVAL;
594 goto out;
595
596 found:
597
598 /* Make snapshot of current debug areas to get it consistent. */
599 /* To copy all the areas is only needed, if we have a view which */
600 /* formats the debug areas. */
601
602 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
603 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
604 else
605 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
606
607 if (!debug_info_snapshot) {
608 rc = -ENOMEM;
609 goto out;
610 }
611 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
612 if (!p_info) {
613 debug_info_free(debug_info_snapshot);
614 rc = -ENOMEM;
615 goto out;
616 }
617 p_info->offset = 0;
618 p_info->debug_info_snap = debug_info_snapshot;
619 p_info->debug_info_org = debug_info;
620 p_info->view = debug_info->views[i];
621 p_info->act_area = 0;
622 p_info->act_page = 0;
623 p_info->act_entry = DEBUG_PROLOG_ENTRY;
624 p_info->act_entry_offset = 0;
625 file->private_data = p_info;
626 debug_info_get(debug_info);
627 nonseekable_open(inode, file);
628 out:
629 mutex_unlock(&debug_mutex);
630 return rc;
631 }
632
633 /*
634 * debug_close:
635 * - called for user close()
636 * - deletes private_data area of the file handle
637 */
638 static int debug_close(struct inode *inode, struct file *file)
639 {
640 file_private_info_t *p_info;
641
642 p_info = (file_private_info_t *) file->private_data;
643 if (p_info->debug_info_snap)
644 debug_info_free(p_info->debug_info_snap);
645 debug_info_put(p_info->debug_info_org);
646 kfree(file->private_data);
647 return 0; /* success */
648 }
649
650 /*
651 * debug_register_mode:
652 * - Creates and initializes debug area for the caller
653 * The mode parameter allows to specify access rights for the s390dbf files
654 * - Returns handle for debug area
655 */
656 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
657 int nr_areas, int buf_size, umode_t mode,
658 uid_t uid, gid_t gid)
659 {
660 debug_info_t *rc = NULL;
661
662 /* Since debugfs currently does not support uid/gid other than root, */
663 /* we do not allow gid/uid != 0 until we get support for that. */
664 if ((uid != 0) || (gid != 0))
665 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
666 BUG_ON(!initialized);
667 mutex_lock(&debug_mutex);
668
669 /* create new debug_info */
670 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
671 if (!rc)
672 goto out;
673 debug_register_view(rc, &debug_level_view);
674 debug_register_view(rc, &debug_flush_view);
675 debug_register_view(rc, &debug_pages_view);
676 out:
677 if (!rc)
678 pr_err("Registering debug feature %s failed\n", name);
679 mutex_unlock(&debug_mutex);
680 return rc;
681 }
682 EXPORT_SYMBOL(debug_register_mode);
683
684 /*
685 * debug_register:
686 * - creates and initializes debug area for the caller
687 * - returns handle for debug area
688 */
689 debug_info_t *debug_register(const char *name, int pages_per_area,
690 int nr_areas, int buf_size)
691 {
692 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
693 S_IRUSR | S_IWUSR, 0, 0);
694 }
695 EXPORT_SYMBOL(debug_register);
696
697 /*
698 * debug_unregister:
699 * - give back debug area
700 */
701 void debug_unregister(debug_info_t *id)
702 {
703 if (!id)
704 return;
705 mutex_lock(&debug_mutex);
706 debug_info_put(id);
707 mutex_unlock(&debug_mutex);
708 }
709 EXPORT_SYMBOL(debug_unregister);
710
711 /*
712 * debug_set_size:
713 * - set area size (number of pages) and number of areas
714 */
715 static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
716 {
717 debug_entry_t ***new_areas;
718 unsigned long flags;
719 int rc = 0;
720
721 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
722 return -EINVAL;
723 if (pages_per_area > 0) {
724 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
725 if (!new_areas) {
726 pr_info("Allocating memory for %i pages failed\n",
727 pages_per_area);
728 rc = -ENOMEM;
729 goto out;
730 }
731 } else {
732 new_areas = NULL;
733 }
734 spin_lock_irqsave(&id->lock, flags);
735 debug_areas_free(id);
736 id->areas = new_areas;
737 id->nr_areas = nr_areas;
738 id->pages_per_area = pages_per_area;
739 id->active_area = 0;
740 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
741 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
742 spin_unlock_irqrestore(&id->lock, flags);
743 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
744 out:
745 return rc;
746 }
747
748 /*
749 * debug_set_level:
750 * - set actual debug level
751 */
752 void debug_set_level(debug_info_t *id, int new_level)
753 {
754 unsigned long flags;
755
756 if (!id)
757 return;
758 spin_lock_irqsave(&id->lock, flags);
759 if (new_level == DEBUG_OFF_LEVEL) {
760 id->level = DEBUG_OFF_LEVEL;
761 pr_info("%s: switched off\n", id->name);
762 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
763 pr_info("%s: level %i is out of range (%i - %i)\n",
764 id->name, new_level, 0, DEBUG_MAX_LEVEL);
765 } else {
766 id->level = new_level;
767 }
768 spin_unlock_irqrestore(&id->lock, flags);
769 }
770 EXPORT_SYMBOL(debug_set_level);
771
772 /*
773 * proceed_active_entry:
774 * - set active entry to next in the ring buffer
775 */
776 static inline void proceed_active_entry(debug_info_t *id)
777 {
778 if ((id->active_entries[id->active_area] += id->entry_size)
779 > (PAGE_SIZE - id->entry_size)) {
780 id->active_entries[id->active_area] = 0;
781 id->active_pages[id->active_area] =
782 (id->active_pages[id->active_area] + 1) %
783 id->pages_per_area;
784 }
785 }
786
787 /*
788 * proceed_active_area:
789 * - set active area to next in the ring buffer
790 */
791 static inline void proceed_active_area(debug_info_t *id)
792 {
793 id->active_area++;
794 id->active_area = id->active_area % id->nr_areas;
795 }
796
797 /*
798 * get_active_entry:
799 */
800 static inline debug_entry_t *get_active_entry(debug_info_t *id)
801 {
802 return (debug_entry_t *) (((char *) id->areas[id->active_area]
803 [id->active_pages[id->active_area]]) +
804 id->active_entries[id->active_area]);
805 }
806
807 /*
808 * debug_finish_entry:
809 * - set timestamp, caller address, cpu number etc.
810 */
811
812 static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
813 int level, int exception)
814 {
815 active->id.stck = get_tod_clock_fast() -
816 *(unsigned long long *) &tod_clock_base[1];
817 active->id.fields.cpuid = smp_processor_id();
818 active->caller = __builtin_return_address(0);
819 active->id.fields.exception = exception;
820 active->id.fields.level = level;
821 proceed_active_entry(id);
822 if (exception)
823 proceed_active_area(id);
824 }
825
826 static int debug_stoppable = 1;
827 static int debug_active = 1;
828
829 #define CTL_S390DBF_STOPPABLE 5678
830 #define CTL_S390DBF_ACTIVE 5679
831
832 /*
833 * proc handler for the running debug_active sysctl
834 * always allow read, allow write only if debug_stoppable is set or
835 * if debug_active is already off
836 */
837 static int s390dbf_procactive(struct ctl_table *table, int write,
838 void __user *buffer, size_t *lenp, loff_t *ppos)
839 {
840 if (!write || debug_stoppable || !debug_active)
841 return proc_dointvec(table, write, buffer, lenp, ppos);
842 else
843 return 0;
844 }
845
846 static struct ctl_table s390dbf_table[] = {
847 {
848 .procname = "debug_stoppable",
849 .data = &debug_stoppable,
850 .maxlen = sizeof(int),
851 .mode = S_IRUGO | S_IWUSR,
852 .proc_handler = proc_dointvec,
853 },
854 {
855 .procname = "debug_active",
856 .data = &debug_active,
857 .maxlen = sizeof(int),
858 .mode = S_IRUGO | S_IWUSR,
859 .proc_handler = s390dbf_procactive,
860 },
861 { }
862 };
863
864 static struct ctl_table s390dbf_dir_table[] = {
865 {
866 .procname = "s390dbf",
867 .maxlen = 0,
868 .mode = S_IRUGO | S_IXUGO,
869 .child = s390dbf_table,
870 },
871 { }
872 };
873
874 static struct ctl_table_header *s390dbf_sysctl_header;
875
876 void debug_stop_all(void)
877 {
878 if (debug_stoppable)
879 debug_active = 0;
880 }
881 EXPORT_SYMBOL(debug_stop_all);
882
883 void debug_set_critical(void)
884 {
885 debug_critical = 1;
886 }
887
888 /*
889 * debug_event_common:
890 * - write debug entry with given size
891 */
892 debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
893 int len)
894 {
895 debug_entry_t *active;
896 unsigned long flags;
897
898 if (!debug_active || !id->areas)
899 return NULL;
900 if (debug_critical) {
901 if (!spin_trylock_irqsave(&id->lock, flags))
902 return NULL;
903 } else {
904 spin_lock_irqsave(&id->lock, flags);
905 }
906 do {
907 active = get_active_entry(id);
908 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
909 if (len < id->buf_size)
910 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
911 debug_finish_entry(id, active, level, 0);
912 len -= id->buf_size;
913 buf += id->buf_size;
914 } while (len > 0);
915
916 spin_unlock_irqrestore(&id->lock, flags);
917 return active;
918 }
919 EXPORT_SYMBOL(debug_event_common);
920
921 /*
922 * debug_exception_common:
923 * - write debug entry with given size and switch to next debug area
924 */
925 debug_entry_t *debug_exception_common(debug_info_t *id, int level,
926 const void *buf, int len)
927 {
928 debug_entry_t *active;
929 unsigned long flags;
930
931 if (!debug_active || !id->areas)
932 return NULL;
933 if (debug_critical) {
934 if (!spin_trylock_irqsave(&id->lock, flags))
935 return NULL;
936 } else {
937 spin_lock_irqsave(&id->lock, flags);
938 }
939 do {
940 active = get_active_entry(id);
941 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
942 if (len < id->buf_size)
943 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
944 debug_finish_entry(id, active, level, len <= id->buf_size);
945 len -= id->buf_size;
946 buf += id->buf_size;
947 } while (len > 0);
948
949 spin_unlock_irqrestore(&id->lock, flags);
950 return active;
951 }
952 EXPORT_SYMBOL(debug_exception_common);
953
954 /*
955 * counts arguments in format string for sprintf view
956 */
957 static inline int debug_count_numargs(char *string)
958 {
959 int numargs = 0;
960
961 while (*string) {
962 if (*string++ == '%')
963 numargs++;
964 }
965 return numargs;
966 }
967
968 /*
969 * debug_sprintf_event:
970 */
971 debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
972 {
973 debug_sprintf_entry_t *curr_event;
974 debug_entry_t *active;
975 unsigned long flags;
976 int numargs, idx;
977 va_list ap;
978
979 if (!debug_active || !id->areas)
980 return NULL;
981 numargs = debug_count_numargs(string);
982
983 if (debug_critical) {
984 if (!spin_trylock_irqsave(&id->lock, flags))
985 return NULL;
986 } else {
987 spin_lock_irqsave(&id->lock, flags);
988 }
989 active = get_active_entry(id);
990 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
991 va_start(ap, string);
992 curr_event->string = string;
993 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
994 curr_event->args[idx] = va_arg(ap, long);
995 va_end(ap);
996 debug_finish_entry(id, active, level, 0);
997 spin_unlock_irqrestore(&id->lock, flags);
998
999 return active;
1000 }
1001 EXPORT_SYMBOL(__debug_sprintf_event);
1002
1003 /*
1004 * debug_sprintf_exception:
1005 */
1006 debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1007 {
1008 debug_sprintf_entry_t *curr_event;
1009 debug_entry_t *active;
1010 unsigned long flags;
1011 int numargs, idx;
1012 va_list ap;
1013
1014 if (!debug_active || !id->areas)
1015 return NULL;
1016
1017 numargs = debug_count_numargs(string);
1018
1019 if (debug_critical) {
1020 if (!spin_trylock_irqsave(&id->lock, flags))
1021 return NULL;
1022 } else {
1023 spin_lock_irqsave(&id->lock, flags);
1024 }
1025 active = get_active_entry(id);
1026 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1027 va_start(ap, string);
1028 curr_event->string = string;
1029 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1030 curr_event->args[idx] = va_arg(ap, long);
1031 va_end(ap);
1032 debug_finish_entry(id, active, level, 1);
1033 spin_unlock_irqrestore(&id->lock, flags);
1034
1035 return active;
1036 }
1037 EXPORT_SYMBOL(__debug_sprintf_exception);
1038
1039 /*
1040 * debug_register_view:
1041 */
1042 int debug_register_view(debug_info_t *id, struct debug_view *view)
1043 {
1044 unsigned long flags;
1045 struct dentry *pde;
1046 umode_t mode;
1047 int rc = 0;
1048 int i;
1049
1050 if (!id)
1051 goto out;
1052 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1053 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1054 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1055 if (!view->input_proc)
1056 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1057 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1058 id, &debug_file_ops);
1059 spin_lock_irqsave(&id->lock, flags);
1060 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1061 if (!id->views[i])
1062 break;
1063 }
1064 if (i == DEBUG_MAX_VIEWS) {
1065 pr_err("Registering view %s/%s would exceed the maximum "
1066 "number of views %i\n", id->name, view->name, i);
1067 rc = -1;
1068 } else {
1069 id->views[i] = view;
1070 id->debugfs_entries[i] = pde;
1071 }
1072 spin_unlock_irqrestore(&id->lock, flags);
1073 if (rc)
1074 debugfs_remove(pde);
1075 out:
1076 return rc;
1077 }
1078 EXPORT_SYMBOL(debug_register_view);
1079
1080 /*
1081 * debug_unregister_view:
1082 */
1083 int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1084 {
1085 struct dentry *dentry = NULL;
1086 unsigned long flags;
1087 int i, rc = 0;
1088
1089 if (!id)
1090 goto out;
1091 spin_lock_irqsave(&id->lock, flags);
1092 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1093 if (id->views[i] == view)
1094 break;
1095 }
1096 if (i == DEBUG_MAX_VIEWS) {
1097 rc = -1;
1098 } else {
1099 dentry = id->debugfs_entries[i];
1100 id->views[i] = NULL;
1101 id->debugfs_entries[i] = NULL;
1102 }
1103 spin_unlock_irqrestore(&id->lock, flags);
1104 debugfs_remove(dentry);
1105 out:
1106 return rc;
1107 }
1108 EXPORT_SYMBOL(debug_unregister_view);
1109
1110 static inline char *debug_get_user_string(const char __user *user_buf,
1111 size_t user_len)
1112 {
1113 char *buffer;
1114
1115 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1116 if (!buffer)
1117 return ERR_PTR(-ENOMEM);
1118 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1119 kfree(buffer);
1120 return ERR_PTR(-EFAULT);
1121 }
1122 /* got the string, now strip linefeed. */
1123 if (buffer[user_len - 1] == '\n')
1124 buffer[user_len - 1] = 0;
1125 else
1126 buffer[user_len] = 0;
1127 return buffer;
1128 }
1129
1130 static inline int debug_get_uint(char *buf)
1131 {
1132 int rc;
1133
1134 buf = skip_spaces(buf);
1135 rc = simple_strtoul(buf, &buf, 10);
1136 if (*buf)
1137 rc = -EINVAL;
1138 return rc;
1139 }
1140
1141 /*
1142 * functions for debug-views
1143 ***********************************
1144 */
1145
1146 /*
1147 * prints out actual debug level
1148 */
1149
1150 static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1151 char *out_buf)
1152 {
1153 return sprintf(out_buf, "%i\n", id->pages_per_area);
1154 }
1155
1156 /*
1157 * reads new size (number of pages per debug area)
1158 */
1159
1160 static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1161 struct file *file, const char __user *user_buf,
1162 size_t user_len, loff_t *offset)
1163 {
1164 int rc, new_pages;
1165 char *str;
1166
1167 if (user_len > 0x10000)
1168 user_len = 0x10000;
1169 if (*offset != 0) {
1170 rc = -EPIPE;
1171 goto out;
1172 }
1173 str = debug_get_user_string(user_buf, user_len);
1174 if (IS_ERR(str)) {
1175 rc = PTR_ERR(str);
1176 goto out;
1177 }
1178 new_pages = debug_get_uint(str);
1179 if (new_pages < 0) {
1180 rc = -EINVAL;
1181 goto free_str;
1182 }
1183 rc = debug_set_size(id, id->nr_areas, new_pages);
1184 if (rc != 0) {
1185 rc = -EINVAL;
1186 goto free_str;
1187 }
1188 rc = user_len;
1189 free_str:
1190 kfree(str);
1191 out:
1192 *offset += user_len;
1193 return rc; /* number of input characters */
1194 }
1195
1196 /*
1197 * prints out actual debug level
1198 */
1199 static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1200 char *out_buf)
1201 {
1202 int rc = 0;
1203
1204 if (id->level == DEBUG_OFF_LEVEL)
1205 rc = sprintf(out_buf, "-\n");
1206 else
1207 rc = sprintf(out_buf, "%i\n", id->level);
1208 return rc;
1209 }
1210
1211 /*
1212 * reads new debug level
1213 */
1214 static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1215 struct file *file, const char __user *user_buf,
1216 size_t user_len, loff_t *offset)
1217 {
1218 int rc, new_level;
1219 char *str;
1220
1221 if (user_len > 0x10000)
1222 user_len = 0x10000;
1223 if (*offset != 0) {
1224 rc = -EPIPE;
1225 goto out;
1226 }
1227 str = debug_get_user_string(user_buf, user_len);
1228 if (IS_ERR(str)) {
1229 rc = PTR_ERR(str);
1230 goto out;
1231 }
1232 if (str[0] == '-') {
1233 debug_set_level(id, DEBUG_OFF_LEVEL);
1234 rc = user_len;
1235 goto free_str;
1236 } else {
1237 new_level = debug_get_uint(str);
1238 }
1239 if (new_level < 0) {
1240 pr_warn("%s is not a valid level for a debug feature\n", str);
1241 rc = -EINVAL;
1242 } else {
1243 debug_set_level(id, new_level);
1244 rc = user_len;
1245 }
1246 free_str:
1247 kfree(str);
1248 out:
1249 *offset += user_len;
1250 return rc; /* number of input characters */
1251 }
1252
1253 /*
1254 * flushes debug areas
1255 */
1256 static void debug_flush(debug_info_t *id, int area)
1257 {
1258 unsigned long flags;
1259 int i, j;
1260
1261 if (!id || !id->areas)
1262 return;
1263 spin_lock_irqsave(&id->lock, flags);
1264 if (area == DEBUG_FLUSH_ALL) {
1265 id->active_area = 0;
1266 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1267 for (i = 0; i < id->nr_areas; i++) {
1268 id->active_pages[i] = 0;
1269 for (j = 0; j < id->pages_per_area; j++)
1270 memset(id->areas[i][j], 0, PAGE_SIZE);
1271 }
1272 } else if (area >= 0 && area < id->nr_areas) {
1273 id->active_entries[area] = 0;
1274 id->active_pages[area] = 0;
1275 for (i = 0; i < id->pages_per_area; i++)
1276 memset(id->areas[area][i], 0, PAGE_SIZE);
1277 }
1278 spin_unlock_irqrestore(&id->lock, flags);
1279 }
1280
1281 /*
1282 * view function: flushes debug areas
1283 */
1284 static int debug_input_flush_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 input_buf[1];
1289 int rc = user_len;
1290
1291 if (user_len > 0x10000)
1292 user_len = 0x10000;
1293 if (*offset != 0) {
1294 rc = -EPIPE;
1295 goto out;
1296 }
1297 if (copy_from_user(input_buf, user_buf, 1)) {
1298 rc = -EFAULT;
1299 goto out;
1300 }
1301 if (input_buf[0] == '-') {
1302 debug_flush(id, DEBUG_FLUSH_ALL);
1303 goto out;
1304 }
1305 if (isdigit(input_buf[0])) {
1306 int area = ((int) input_buf[0] - (int) '0');
1307
1308 debug_flush(id, area);
1309 goto out;
1310 }
1311
1312 pr_info("Flushing debug data failed because %c is not a valid "
1313 "area\n", input_buf[0]);
1314
1315 out:
1316 *offset += user_len;
1317 return rc; /* number of input characters */
1318 }
1319
1320 /*
1321 * prints debug header in raw format
1322 */
1323 static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1324 int area, debug_entry_t *entry, char *out_buf)
1325 {
1326 int rc;
1327
1328 rc = sizeof(debug_entry_t);
1329 memcpy(out_buf, entry, sizeof(debug_entry_t));
1330 return rc;
1331 }
1332
1333 /*
1334 * prints debug data in raw format
1335 */
1336 static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1337 char *out_buf, const char *in_buf)
1338 {
1339 int rc;
1340
1341 rc = id->buf_size;
1342 memcpy(out_buf, in_buf, id->buf_size);
1343 return rc;
1344 }
1345
1346 /*
1347 * prints debug data in hex/ascii format
1348 */
1349 static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1350 char *out_buf, const char *in_buf)
1351 {
1352 int i, rc = 0;
1353
1354 for (i = 0; i < id->buf_size; i++)
1355 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1356 rc += sprintf(out_buf + rc, "| ");
1357 for (i = 0; i < id->buf_size; i++) {
1358 unsigned char c = in_buf[i];
1359
1360 if (isascii(c) && isprint(c))
1361 rc += sprintf(out_buf + rc, "%c", c);
1362 else
1363 rc += sprintf(out_buf + rc, ".");
1364 }
1365 rc += sprintf(out_buf + rc, "\n");
1366 return rc;
1367 }
1368
1369 /*
1370 * prints header for debug entry
1371 */
1372 int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1373 int area, debug_entry_t *entry, char *out_buf)
1374 {
1375 unsigned long base, sec, usec;
1376 unsigned long caller;
1377 unsigned int level;
1378 char *except_str;
1379 int rc = 0;
1380
1381 level = entry->id.fields.level;
1382 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1383 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1384 usec = do_div(sec, USEC_PER_SEC);
1385
1386 if (entry->id.fields.exception)
1387 except_str = "*";
1388 else
1389 except_str = "-";
1390 caller = (unsigned long) entry->caller;
1391 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1392 area, sec, usec, level, except_str,
1393 entry->id.fields.cpuid, (void *)caller);
1394 return rc;
1395 }
1396 EXPORT_SYMBOL(debug_dflt_header_fn);
1397
1398 /*
1399 * prints debug data sprintf-formated:
1400 * debug_sprinf_event/exception calls must be used together with this view
1401 */
1402
1403 #define DEBUG_SPRINTF_MAX_ARGS 10
1404
1405 static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1406 char *out_buf, debug_sprintf_entry_t *curr_event)
1407 {
1408 int num_longs, num_used_args = 0, i, rc = 0;
1409 int index[DEBUG_SPRINTF_MAX_ARGS];
1410
1411 /* count of longs fit into one entry */
1412 num_longs = id->buf_size / sizeof(long);
1413
1414 if (num_longs < 1)
1415 goto out; /* bufsize of entry too small */
1416 if (num_longs == 1) {
1417 /* no args, we use only the string */
1418 strcpy(out_buf, curr_event->string);
1419 rc = strlen(curr_event->string);
1420 goto out;
1421 }
1422
1423 /* number of arguments used for sprintf (without the format string) */
1424 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1425
1426 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1427
1428 for (i = 0; i < num_used_args; i++)
1429 index[i] = i;
1430
1431 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1432 curr_event->args[index[1]], curr_event->args[index[2]],
1433 curr_event->args[index[3]], curr_event->args[index[4]],
1434 curr_event->args[index[5]], curr_event->args[index[6]],
1435 curr_event->args[index[7]], curr_event->args[index[8]],
1436 curr_event->args[index[9]]);
1437 out:
1438 return rc;
1439 }
1440
1441 /*
1442 * debug_init:
1443 * - is called exactly once to initialize the debug feature
1444 */
1445 static int __init debug_init(void)
1446 {
1447 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1448 mutex_lock(&debug_mutex);
1449 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1450 initialized = 1;
1451 mutex_unlock(&debug_mutex);
1452 return 0;
1453 }
1454 postcore_initcall(debug_init);
Linux with added FPC-III support