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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
38typedef 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
54typedef 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
67static int debug_init(void);
68static ssize_t debug_output(struct file *file, char __user *user_buf,
69 size_t user_len, loff_t *offset);
70static ssize_t debug_input(struct file *file, const char __user *user_buf,
71 size_t user_len, loff_t *offset);
72static int debug_open(struct inode *inode, struct file *file);
73static int debug_close(struct inode *inode, struct file *file);
74static debug_info_t *debug_info_create(const char *name, int pages_per_area,
75 int nr_areas, int buf_size, umode_t mode);
76static void debug_info_get(debug_info_t *);
77static void debug_info_put(debug_info_t *);
78static int debug_prolog_level_fn(debug_info_t *id,
79 struct debug_view *view, char *out_buf);
80static 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);
83static int debug_prolog_pages_fn(debug_info_t *id,
84 struct debug_view *view, char *out_buf);
85static 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);
88static 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);
91static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
92 char *out_buf, const char *in_buf);
93static int debug_raw_format_fn(debug_info_t *id,
94 struct debug_view *view, char *out_buf,
95 const char *in_buf);
96static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
97 int area, debug_entry_t *entry, char *out_buf);
98
99static 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
104struct debug_view debug_raw_view = {
105 "raw",
106 NULL,
107 &debug_raw_header_fn,
108 &debug_raw_format_fn,
109 NULL,
110 NULL
111};
112EXPORT_SYMBOL(debug_raw_view);
113
114struct 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};
122EXPORT_SYMBOL(debug_hex_ascii_view);
123
124static 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
133static 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
142static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149};
150
151struct 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};
159EXPORT_SYMBOL(debug_sprintf_view);
160
161/* used by dump analysis tools to determine version of debug feature */
162static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
163
164/* static globals */
165
166static debug_info_t *debug_area_first;
167static debug_info_t *debug_area_last;
168static DEFINE_MUTEX(debug_mutex);
169
170static int initialized;
171static int debug_critical;
172
173static 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
182static 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
192static 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(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(pages_per_area * sizeof(debug_entry_t *), GFP_KERNEL);
202 if (!areas[i])
203 goto fail_malloc_areas2;
204 for (j = 0; j < pages_per_area; j++) {
205 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
206 if (!areas[i][j]) {
207 for (j--; j >= 0 ; j--)
208 kfree(areas[i][j]);
209 kfree(areas[i]);
210 goto fail_malloc_areas2;
211 }
212 }
213 }
214 return areas;
215
216fail_malloc_areas2:
217 for (i--; i >= 0; i--) {
218 for (j = 0; j < pages_per_area; j++)
219 kfree(areas[i][j]);
220 kfree(areas[i]);
221 }
222 kfree(areas);
223fail_malloc_areas:
224 return NULL;
225}
226
227/*
228 * debug_info_alloc
229 * - alloc new debug-info
230 */
231static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
232 int nr_areas, int buf_size, int level,
233 int mode)
234{
235 debug_info_t *rc;
236
237 /* alloc everything */
238 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
239 if (!rc)
240 goto fail_malloc_rc;
241 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
242 if (!rc->active_entries)
243 goto fail_malloc_active_entries;
244 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
245 if (!rc->active_pages)
246 goto fail_malloc_active_pages;
247 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
248 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
249 if (!rc->areas)
250 goto fail_malloc_areas;
251 } else {
252 rc->areas = NULL;
253 }
254
255 /* initialize members */
256 spin_lock_init(&rc->lock);
257 rc->pages_per_area = pages_per_area;
258 rc->nr_areas = nr_areas;
259 rc->active_area = 0;
260 rc->level = level;
261 rc->buf_size = buf_size;
262 rc->entry_size = sizeof(debug_entry_t) + buf_size;
263 strlcpy(rc->name, name, sizeof(rc->name));
264 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
265 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
266 refcount_set(&(rc->ref_count), 0);
267
268 return rc;
269
270fail_malloc_areas:
271 kfree(rc->active_pages);
272fail_malloc_active_pages:
273 kfree(rc->active_entries);
274fail_malloc_active_entries:
275 kfree(rc);
276fail_malloc_rc:
277 return NULL;
278}
279
280/*
281 * debug_areas_free
282 * - free all debug areas
283 */
284static void debug_areas_free(debug_info_t *db_info)
285{
286 int i, j;
287
288 if (!db_info->areas)
289 return;
290 for (i = 0; i < db_info->nr_areas; i++) {
291 for (j = 0; j < db_info->pages_per_area; j++)
292 kfree(db_info->areas[i][j]);
293 kfree(db_info->areas[i]);
294 }
295 kfree(db_info->areas);
296 db_info->areas = NULL;
297}
298
299/*
300 * debug_info_free
301 * - free memory debug-info
302 */
303static void debug_info_free(debug_info_t *db_info)
304{
305 debug_areas_free(db_info);
306 kfree(db_info->active_entries);
307 kfree(db_info->active_pages);
308 kfree(db_info);
309}
310
311/*
312 * debug_info_create
313 * - create new debug-info
314 */
315
316static debug_info_t *debug_info_create(const char *name, int pages_per_area,
317 int nr_areas, int buf_size, umode_t mode)
318{
319 debug_info_t *rc;
320
321 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
322 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
323 if (!rc)
324 goto out;
325
326 rc->mode = mode & ~S_IFMT;
327
328 /* create root directory */
329 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
330 debug_debugfs_root_entry);
331
332 /* append new element to linked list */
333 if (!debug_area_first) {
334 /* first element in list */
335 debug_area_first = rc;
336 rc->prev = NULL;
337 } else {
338 /* append element to end of list */
339 debug_area_last->next = rc;
340 rc->prev = debug_area_last;
341 }
342 debug_area_last = rc;
343 rc->next = NULL;
344
345 refcount_set(&rc->ref_count, 1);
346out:
347 return rc;
348}
349
350/*
351 * debug_info_copy
352 * - copy debug-info
353 */
354static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
355{
356 unsigned long flags;
357 debug_info_t *rc;
358 int i, j;
359
360 /* get a consistent copy of the debug areas */
361 do {
362 rc = debug_info_alloc(in->name, in->pages_per_area,
363 in->nr_areas, in->buf_size, in->level, mode);
364 spin_lock_irqsave(&in->lock, flags);
365 if (!rc)
366 goto out;
367 /* has something changed in the meantime ? */
368 if ((rc->pages_per_area == in->pages_per_area) &&
369 (rc->nr_areas == in->nr_areas)) {
370 break;
371 }
372 spin_unlock_irqrestore(&in->lock, flags);
373 debug_info_free(rc);
374 } while (1);
375
376 if (mode == NO_AREAS)
377 goto out;
378
379 for (i = 0; i < in->nr_areas; i++) {
380 for (j = 0; j < in->pages_per_area; j++)
381 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
382 }
383out:
384 spin_unlock_irqrestore(&in->lock, flags);
385 return rc;
386}
387
388/*
389 * debug_info_get
390 * - increments reference count for debug-info
391 */
392static void debug_info_get(debug_info_t *db_info)
393{
394 if (db_info)
395 refcount_inc(&db_info->ref_count);
396}
397
398/*
399 * debug_info_put:
400 * - decreases reference count for debug-info and frees it if necessary
401 */
402static void debug_info_put(debug_info_t *db_info)
403{
404 int i;
405
406 if (!db_info)
407 return;
408 if (refcount_dec_and_test(&db_info->ref_count)) {
409 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
410 if (!db_info->views[i])
411 continue;
412 debugfs_remove(db_info->debugfs_entries[i]);
413 }
414 debugfs_remove(db_info->debugfs_root_entry);
415 if (db_info == debug_area_first)
416 debug_area_first = db_info->next;
417 if (db_info == debug_area_last)
418 debug_area_last = db_info->prev;
419 if (db_info->prev)
420 db_info->prev->next = db_info->next;
421 if (db_info->next)
422 db_info->next->prev = db_info->prev;
423 debug_info_free(db_info);
424 }
425}
426
427/*
428 * debug_format_entry:
429 * - format one debug entry and return size of formated data
430 */
431static int debug_format_entry(file_private_info_t *p_info)
432{
433 debug_info_t *id_snap = p_info->debug_info_snap;
434 struct debug_view *view = p_info->view;
435 debug_entry_t *act_entry;
436 size_t len = 0;
437
438 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
439 /* print prolog */
440 if (view->prolog_proc)
441 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
442 goto out;
443 }
444 if (!id_snap->areas) /* this is true, if we have a prolog only view */
445 goto out; /* or if 'pages_per_area' is 0 */
446 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
447 [p_info->act_page] + p_info->act_entry);
448
449 if (act_entry->id.stck == 0LL)
450 goto out; /* empty entry */
451 if (view->header_proc)
452 len += view->header_proc(id_snap, view, p_info->act_area,
453 act_entry, p_info->temp_buf + len);
454 if (view->format_proc)
455 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
456 DEBUG_DATA(act_entry));
457out:
458 return len;
459}
460
461/*
462 * debug_next_entry:
463 * - goto next entry in p_info
464 */
465static inline int debug_next_entry(file_private_info_t *p_info)
466{
467 debug_info_t *id;
468
469 id = p_info->debug_info_snap;
470 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
471 p_info->act_entry = 0;
472 p_info->act_page = 0;
473 goto out;
474 }
475 if (!id->areas)
476 return 1;
477 p_info->act_entry += id->entry_size;
478 /* switch to next page, if we reached the end of the page */
479 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
480 /* next page */
481 p_info->act_entry = 0;
482 p_info->act_page += 1;
483 if ((p_info->act_page % id->pages_per_area) == 0) {
484 /* next area */
485 p_info->act_area++;
486 p_info->act_page = 0;
487 }
488 if (p_info->act_area >= id->nr_areas)
489 return 1;
490 }
491out:
492 return 0;
493}
494
495/*
496 * debug_output:
497 * - called for user read()
498 * - copies formated debug entries to the user buffer
499 */
500static ssize_t debug_output(struct file *file, /* file descriptor */
501 char __user *user_buf, /* user buffer */
502 size_t len, /* length of buffer */
503 loff_t *offset) /* offset in the file */
504{
505 size_t count = 0;
506 size_t entry_offset;
507 file_private_info_t *p_info;
508
509 p_info = (file_private_info_t *) file->private_data;
510 if (*offset != p_info->offset)
511 return -EPIPE;
512 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
513 return 0;
514 entry_offset = p_info->act_entry_offset;
515 while (count < len) {
516 int formatted_line_residue;
517 int formatted_line_size;
518 int user_buf_residue;
519 size_t copy_size;
520
521 formatted_line_size = debug_format_entry(p_info);
522 formatted_line_residue = formatted_line_size - entry_offset;
523 user_buf_residue = len-count;
524 copy_size = min(user_buf_residue, formatted_line_residue);
525 if (copy_size) {
526 if (copy_to_user(user_buf + count, p_info->temp_buf
527 + entry_offset, copy_size))
528 return -EFAULT;
529 count += copy_size;
530 entry_offset += copy_size;
531 }
532 if (copy_size == formatted_line_residue) {
533 entry_offset = 0;
534 if (debug_next_entry(p_info))
535 goto out;
536 }
537 }
538out:
539 p_info->offset = *offset + count;
540 p_info->act_entry_offset = entry_offset;
541 *offset = p_info->offset;
542 return count;
543}
544
545/*
546 * debug_input:
547 * - called for user write()
548 * - calls input function of view
549 */
550static ssize_t debug_input(struct file *file, const char __user *user_buf,
551 size_t length, loff_t *offset)
552{
553 file_private_info_t *p_info;
554 int rc = 0;
555
556 mutex_lock(&debug_mutex);
557 p_info = ((file_private_info_t *) file->private_data);
558 if (p_info->view->input_proc) {
559 rc = p_info->view->input_proc(p_info->debug_info_org,
560 p_info->view, file, user_buf,
561 length, offset);
562 } else {
563 rc = -EPERM;
564 }
565 mutex_unlock(&debug_mutex);
566 return rc; /* number of input characters */
567}
568
569/*
570 * debug_open:
571 * - called for user open()
572 * - copies formated output to private_data area of the file
573 * handle
574 */
575static int debug_open(struct inode *inode, struct file *file)
576{
577 debug_info_t *debug_info, *debug_info_snapshot;
578 file_private_info_t *p_info;
579 int i, rc = 0;
580
581 mutex_lock(&debug_mutex);
582 debug_info = file_inode(file)->i_private;
583 /* find debug view */
584 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
585 if (!debug_info->views[i])
586 continue;
587 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
588 goto found; /* found view ! */
589 }
590 /* no entry found */
591 rc = -EINVAL;
592 goto out;
593
594found:
595
596 /* Make snapshot of current debug areas to get it consistent. */
597 /* To copy all the areas is only needed, if we have a view which */
598 /* formats the debug areas. */
599
600 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
601 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
602 else
603 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
604
605 if (!debug_info_snapshot) {
606 rc = -ENOMEM;
607 goto out;
608 }
609 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
610 if (!p_info) {
611 debug_info_free(debug_info_snapshot);
612 rc = -ENOMEM;
613 goto out;
614 }
615 p_info->offset = 0;
616 p_info->debug_info_snap = debug_info_snapshot;
617 p_info->debug_info_org = debug_info;
618 p_info->view = debug_info->views[i];
619 p_info->act_area = 0;
620 p_info->act_page = 0;
621 p_info->act_entry = DEBUG_PROLOG_ENTRY;
622 p_info->act_entry_offset = 0;
623 file->private_data = p_info;
624 debug_info_get(debug_info);
625 nonseekable_open(inode, file);
626out:
627 mutex_unlock(&debug_mutex);
628 return rc;
629}
630
631/*
632 * debug_close:
633 * - called for user close()
634 * - deletes private_data area of the file handle
635 */
636static int debug_close(struct inode *inode, struct file *file)
637{
638 file_private_info_t *p_info;
639
640 p_info = (file_private_info_t *) file->private_data;
641 if (p_info->debug_info_snap)
642 debug_info_free(p_info->debug_info_snap);
643 debug_info_put(p_info->debug_info_org);
644 kfree(file->private_data);
645 return 0; /* success */
646}
647
648/*
649 * debug_register_mode:
650 * - Creates and initializes debug area for the caller
651 * The mode parameter allows to specify access rights for the s390dbf files
652 * - Returns handle for debug area
653 */
654debug_info_t *debug_register_mode(const char *name, int pages_per_area,
655 int nr_areas, int buf_size, umode_t mode,
656 uid_t uid, gid_t gid)
657{
658 debug_info_t *rc = NULL;
659
660 /* Since debugfs currently does not support uid/gid other than root, */
661 /* we do not allow gid/uid != 0 until we get support for that. */
662 if ((uid != 0) || (gid != 0))
663 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
664 BUG_ON(!initialized);
665 mutex_lock(&debug_mutex);
666
667 /* create new debug_info */
668 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
669 if (!rc)
670 goto out;
671 debug_register_view(rc, &debug_level_view);
672 debug_register_view(rc, &debug_flush_view);
673 debug_register_view(rc, &debug_pages_view);
674out:
675 if (!rc)
676 pr_err("Registering debug feature %s failed\n", name);
677 mutex_unlock(&debug_mutex);
678 return rc;
679}
680EXPORT_SYMBOL(debug_register_mode);
681
682/*
683 * debug_register:
684 * - creates and initializes debug area for the caller
685 * - returns handle for debug area
686 */
687debug_info_t *debug_register(const char *name, int pages_per_area,
688 int nr_areas, int buf_size)
689{
690 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
691 S_IRUSR | S_IWUSR, 0, 0);
692}
693EXPORT_SYMBOL(debug_register);
694
695/*
696 * debug_unregister:
697 * - give back debug area
698 */
699void debug_unregister(debug_info_t *id)
700{
701 if (!id)
702 return;
703 mutex_lock(&debug_mutex);
704 debug_info_put(id);
705 mutex_unlock(&debug_mutex);
706}
707EXPORT_SYMBOL(debug_unregister);
708
709/*
710 * debug_set_size:
711 * - set area size (number of pages) and number of areas
712 */
713static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
714{
715 debug_entry_t ***new_areas;
716 unsigned long flags;
717 int rc = 0;
718
719 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
720 return -EINVAL;
721 if (pages_per_area > 0) {
722 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
723 if (!new_areas) {
724 pr_info("Allocating memory for %i pages failed\n",
725 pages_per_area);
726 rc = -ENOMEM;
727 goto out;
728 }
729 } else {
730 new_areas = NULL;
731 }
732 spin_lock_irqsave(&id->lock, flags);
733 debug_areas_free(id);
734 id->areas = new_areas;
735 id->nr_areas = nr_areas;
736 id->pages_per_area = pages_per_area;
737 id->active_area = 0;
738 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
739 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
740 spin_unlock_irqrestore(&id->lock, flags);
741 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
742out:
743 return rc;
744}
745
746/*
747 * debug_set_level:
748 * - set actual debug level
749 */
750void debug_set_level(debug_info_t *id, int new_level)
751{
752 unsigned long flags;
753
754 if (!id)
755 return;
756 spin_lock_irqsave(&id->lock, flags);
757 if (new_level == DEBUG_OFF_LEVEL) {
758 id->level = DEBUG_OFF_LEVEL;
759 pr_info("%s: switched off\n", id->name);
760 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
761 pr_info("%s: level %i is out of range (%i - %i)\n",
762 id->name, new_level, 0, DEBUG_MAX_LEVEL);
763 } else {
764 id->level = new_level;
765 }
766 spin_unlock_irqrestore(&id->lock, flags);
767}
768EXPORT_SYMBOL(debug_set_level);
769
770/*
771 * proceed_active_entry:
772 * - set active entry to next in the ring buffer
773 */
774static inline void proceed_active_entry(debug_info_t *id)
775{
776 if ((id->active_entries[id->active_area] += id->entry_size)
777 > (PAGE_SIZE - id->entry_size)) {
778 id->active_entries[id->active_area] = 0;
779 id->active_pages[id->active_area] =
780 (id->active_pages[id->active_area] + 1) %
781 id->pages_per_area;
782 }
783}
784
785/*
786 * proceed_active_area:
787 * - set active area to next in the ring buffer
788 */
789static inline void proceed_active_area(debug_info_t *id)
790{
791 id->active_area++;
792 id->active_area = id->active_area % id->nr_areas;
793}
794
795/*
796 * get_active_entry:
797 */
798static inline debug_entry_t *get_active_entry(debug_info_t *id)
799{
800 return (debug_entry_t *) (((char *) id->areas[id->active_area]
801 [id->active_pages[id->active_area]]) +
802 id->active_entries[id->active_area]);
803}
804
805/*
806 * debug_finish_entry:
807 * - set timestamp, caller address, cpu number etc.
808 */
809
810static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
811 int level, int exception)
812{
813 active->id.stck = get_tod_clock_fast() -
814 *(unsigned long long *) &tod_clock_base[1];
815 active->id.fields.cpuid = smp_processor_id();
816 active->caller = __builtin_return_address(0);
817 active->id.fields.exception = exception;
818 active->id.fields.level = level;
819 proceed_active_entry(id);
820 if (exception)
821 proceed_active_area(id);
822}
823
824static int debug_stoppable = 1;
825static int debug_active = 1;
826
827#define CTL_S390DBF_STOPPABLE 5678
828#define CTL_S390DBF_ACTIVE 5679
829
830/*
831 * proc handler for the running debug_active sysctl
832 * always allow read, allow write only if debug_stoppable is set or
833 * if debug_active is already off
834 */
835static int s390dbf_procactive(struct ctl_table *table, int write,
836 void __user *buffer, size_t *lenp, loff_t *ppos)
837{
838 if (!write || debug_stoppable || !debug_active)
839 return proc_dointvec(table, write, buffer, lenp, ppos);
840 else
841 return 0;
842}
843
844static struct ctl_table s390dbf_table[] = {
845 {
846 .procname = "debug_stoppable",
847 .data = &debug_stoppable,
848 .maxlen = sizeof(int),
849 .mode = S_IRUGO | S_IWUSR,
850 .proc_handler = proc_dointvec,
851 },
852 {
853 .procname = "debug_active",
854 .data = &debug_active,
855 .maxlen = sizeof(int),
856 .mode = S_IRUGO | S_IWUSR,
857 .proc_handler = s390dbf_procactive,
858 },
859 { }
860};
861
862static struct ctl_table s390dbf_dir_table[] = {
863 {
864 .procname = "s390dbf",
865 .maxlen = 0,
866 .mode = S_IRUGO | S_IXUGO,
867 .child = s390dbf_table,
868 },
869 { }
870};
871
872static struct ctl_table_header *s390dbf_sysctl_header;
873
874void debug_stop_all(void)
875{
876 if (debug_stoppable)
877 debug_active = 0;
878}
879EXPORT_SYMBOL(debug_stop_all);
880
881void debug_set_critical(void)
882{
883 debug_critical = 1;
884}
885
886/*
887 * debug_event_common:
888 * - write debug entry with given size
889 */
890debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
891 int len)
892{
893 debug_entry_t *active;
894 unsigned long flags;
895
896 if (!debug_active || !id->areas)
897 return NULL;
898 if (debug_critical) {
899 if (!spin_trylock_irqsave(&id->lock, flags))
900 return NULL;
901 } else {
902 spin_lock_irqsave(&id->lock, flags);
903 }
904 do {
905 active = get_active_entry(id);
906 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
907 if (len < id->buf_size)
908 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
909 debug_finish_entry(id, active, level, 0);
910 len -= id->buf_size;
911 buf += id->buf_size;
912 } while (len > 0);
913
914 spin_unlock_irqrestore(&id->lock, flags);
915 return active;
916}
917EXPORT_SYMBOL(debug_event_common);
918
919/*
920 * debug_exception_common:
921 * - write debug entry with given size and switch to next debug area
922 */
923debug_entry_t *debug_exception_common(debug_info_t *id, int level,
924 const void *buf, int len)
925{
926 debug_entry_t *active;
927 unsigned long flags;
928
929 if (!debug_active || !id->areas)
930 return NULL;
931 if (debug_critical) {
932 if (!spin_trylock_irqsave(&id->lock, flags))
933 return NULL;
934 } else {
935 spin_lock_irqsave(&id->lock, flags);
936 }
937 do {
938 active = get_active_entry(id);
939 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
940 if (len < id->buf_size)
941 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
942 debug_finish_entry(id, active, level, len <= id->buf_size);
943 len -= id->buf_size;
944 buf += id->buf_size;
945 } while (len > 0);
946
947 spin_unlock_irqrestore(&id->lock, flags);
948 return active;
949}
950EXPORT_SYMBOL(debug_exception_common);
951
952/*
953 * counts arguments in format string for sprintf view
954 */
955static inline int debug_count_numargs(char *string)
956{
957 int numargs = 0;
958
959 while (*string) {
960 if (*string++ == '%')
961 numargs++;
962 }
963 return numargs;
964}
965
966/*
967 * debug_sprintf_event:
968 */
969debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
970{
971 debug_sprintf_entry_t *curr_event;
972 debug_entry_t *active;
973 unsigned long flags;
974 int numargs, idx;
975 va_list ap;
976
977 if (!debug_active || !id->areas)
978 return NULL;
979 numargs = debug_count_numargs(string);
980
981 if (debug_critical) {
982 if (!spin_trylock_irqsave(&id->lock, flags))
983 return NULL;
984 } else {
985 spin_lock_irqsave(&id->lock, flags);
986 }
987 active = get_active_entry(id);
988 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
989 va_start(ap, string);
990 curr_event->string = string;
991 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
992 curr_event->args[idx] = va_arg(ap, long);
993 va_end(ap);
994 debug_finish_entry(id, active, level, 0);
995 spin_unlock_irqrestore(&id->lock, flags);
996
997 return active;
998}
999EXPORT_SYMBOL(__debug_sprintf_event);
1000
1001/*
1002 * debug_sprintf_exception:
1003 */
1004debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1005{
1006 debug_sprintf_entry_t *curr_event;
1007 debug_entry_t *active;
1008 unsigned long flags;
1009 int numargs, idx;
1010 va_list ap;
1011
1012 if (!debug_active || !id->areas)
1013 return NULL;
1014
1015 numargs = debug_count_numargs(string);
1016
1017 if (debug_critical) {
1018 if (!spin_trylock_irqsave(&id->lock, flags))
1019 return NULL;
1020 } else {
1021 spin_lock_irqsave(&id->lock, flags);
1022 }
1023 active = get_active_entry(id);
1024 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1025 va_start(ap, string);
1026 curr_event->string = string;
1027 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1028 curr_event->args[idx] = va_arg(ap, long);
1029 va_end(ap);
1030 debug_finish_entry(id, active, level, 1);
1031 spin_unlock_irqrestore(&id->lock, flags);
1032
1033 return active;
1034}
1035EXPORT_SYMBOL(__debug_sprintf_exception);
1036
1037/*
1038 * debug_register_view:
1039 */
1040int debug_register_view(debug_info_t *id, struct debug_view *view)
1041{
1042 unsigned long flags;
1043 struct dentry *pde;
1044 umode_t mode;
1045 int rc = 0;
1046 int i;
1047
1048 if (!id)
1049 goto out;
1050 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1051 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1052 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1053 if (!view->input_proc)
1054 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1055 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1056 id, &debug_file_ops);
1057 if (!pde) {
1058 pr_err("Registering view %s/%s failed due to out of "
1059 "memory\n", id->name, view->name);
1060 rc = -1;
1061 goto out;
1062 }
1063 spin_lock_irqsave(&id->lock, flags);
1064 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1065 if (!id->views[i])
1066 break;
1067 }
1068 if (i == DEBUG_MAX_VIEWS) {
1069 pr_err("Registering view %s/%s would exceed the maximum "
1070 "number of views %i\n", id->name, view->name, i);
1071 rc = -1;
1072 } else {
1073 id->views[i] = view;
1074 id->debugfs_entries[i] = pde;
1075 }
1076 spin_unlock_irqrestore(&id->lock, flags);
1077 if (rc)
1078 debugfs_remove(pde);
1079out:
1080 return rc;
1081}
1082EXPORT_SYMBOL(debug_register_view);
1083
1084/*
1085 * debug_unregister_view:
1086 */
1087int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1088{
1089 struct dentry *dentry = NULL;
1090 unsigned long flags;
1091 int i, rc = 0;
1092
1093 if (!id)
1094 goto out;
1095 spin_lock_irqsave(&id->lock, flags);
1096 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1097 if (id->views[i] == view)
1098 break;
1099 }
1100 if (i == DEBUG_MAX_VIEWS) {
1101 rc = -1;
1102 } else {
1103 dentry = id->debugfs_entries[i];
1104 id->views[i] = NULL;
1105 id->debugfs_entries[i] = NULL;
1106 }
1107 spin_unlock_irqrestore(&id->lock, flags);
1108 debugfs_remove(dentry);
1109out:
1110 return rc;
1111}
1112EXPORT_SYMBOL(debug_unregister_view);
1113
1114static inline char *debug_get_user_string(const char __user *user_buf,
1115 size_t user_len)
1116{
1117 char *buffer;
1118
1119 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1120 if (!buffer)
1121 return ERR_PTR(-ENOMEM);
1122 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1123 kfree(buffer);
1124 return ERR_PTR(-EFAULT);
1125 }
1126 /* got the string, now strip linefeed. */
1127 if (buffer[user_len - 1] == '\n')
1128 buffer[user_len - 1] = 0;
1129 else
1130 buffer[user_len] = 0;
1131 return buffer;
1132}
1133
1134static inline int debug_get_uint(char *buf)
1135{
1136 int rc;
1137
1138 buf = skip_spaces(buf);
1139 rc = simple_strtoul(buf, &buf, 10);
1140 if (*buf)
1141 rc = -EINVAL;
1142 return rc;
1143}
1144
1145/*
1146 * functions for debug-views
1147 ***********************************
1148*/
1149
1150/*
1151 * prints out actual debug level
1152 */
1153
1154static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1155 char *out_buf)
1156{
1157 return sprintf(out_buf, "%i\n", id->pages_per_area);
1158}
1159
1160/*
1161 * reads new size (number of pages per debug area)
1162 */
1163
1164static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1165 struct file *file, const char __user *user_buf,
1166 size_t user_len, loff_t *offset)
1167{
1168 int rc, new_pages;
1169 char *str;
1170
1171 if (user_len > 0x10000)
1172 user_len = 0x10000;
1173 if (*offset != 0) {
1174 rc = -EPIPE;
1175 goto out;
1176 }
1177 str = debug_get_user_string(user_buf, user_len);
1178 if (IS_ERR(str)) {
1179 rc = PTR_ERR(str);
1180 goto out;
1181 }
1182 new_pages = debug_get_uint(str);
1183 if (new_pages < 0) {
1184 rc = -EINVAL;
1185 goto free_str;
1186 }
1187 rc = debug_set_size(id, id->nr_areas, new_pages);
1188 if (rc != 0) {
1189 rc = -EINVAL;
1190 goto free_str;
1191 }
1192 rc = user_len;
1193free_str:
1194 kfree(str);
1195out:
1196 *offset += user_len;
1197 return rc; /* number of input characters */
1198}
1199
1200/*
1201 * prints out actual debug level
1202 */
1203static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1204 char *out_buf)
1205{
1206 int rc = 0;
1207
1208 if (id->level == DEBUG_OFF_LEVEL)
1209 rc = sprintf(out_buf, "-\n");
1210 else
1211 rc = sprintf(out_buf, "%i\n", id->level);
1212 return rc;
1213}
1214
1215/*
1216 * reads new debug level
1217 */
1218static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1219 struct file *file, const char __user *user_buf,
1220 size_t user_len, loff_t *offset)
1221{
1222 int rc, new_level;
1223 char *str;
1224
1225 if (user_len > 0x10000)
1226 user_len = 0x10000;
1227 if (*offset != 0) {
1228 rc = -EPIPE;
1229 goto out;
1230 }
1231 str = debug_get_user_string(user_buf, user_len);
1232 if (IS_ERR(str)) {
1233 rc = PTR_ERR(str);
1234 goto out;
1235 }
1236 if (str[0] == '-') {
1237 debug_set_level(id, DEBUG_OFF_LEVEL);
1238 rc = user_len;
1239 goto free_str;
1240 } else {
1241 new_level = debug_get_uint(str);
1242 }
1243 if (new_level < 0) {
1244 pr_warn("%s is not a valid level for a debug feature\n", str);
1245 rc = -EINVAL;
1246 } else {
1247 debug_set_level(id, new_level);
1248 rc = user_len;
1249 }
1250free_str:
1251 kfree(str);
1252out:
1253 *offset += user_len;
1254 return rc; /* number of input characters */
1255}
1256
1257/*
1258 * flushes debug areas
1259 */
1260static void debug_flush(debug_info_t *id, int area)
1261{
1262 unsigned long flags;
1263 int i, j;
1264
1265 if (!id || !id->areas)
1266 return;
1267 spin_lock_irqsave(&id->lock, flags);
1268 if (area == DEBUG_FLUSH_ALL) {
1269 id->active_area = 0;
1270 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1271 for (i = 0; i < id->nr_areas; i++) {
1272 id->active_pages[i] = 0;
1273 for (j = 0; j < id->pages_per_area; j++)
1274 memset(id->areas[i][j], 0, PAGE_SIZE);
1275 }
1276 } else if (area >= 0 && area < id->nr_areas) {
1277 id->active_entries[area] = 0;
1278 id->active_pages[area] = 0;
1279 for (i = 0; i < id->pages_per_area; i++)
1280 memset(id->areas[area][i], 0, PAGE_SIZE);
1281 }
1282 spin_unlock_irqrestore(&id->lock, flags);
1283}
1284
1285/*
1286 * view function: flushes debug areas
1287 */
1288static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1289 struct file *file, const char __user *user_buf,
1290 size_t user_len, loff_t *offset)
1291{
1292 char input_buf[1];
1293 int rc = user_len;
1294
1295 if (user_len > 0x10000)
1296 user_len = 0x10000;
1297 if (*offset != 0) {
1298 rc = -EPIPE;
1299 goto out;
1300 }
1301 if (copy_from_user(input_buf, user_buf, 1)) {
1302 rc = -EFAULT;
1303 goto out;
1304 }
1305 if (input_buf[0] == '-') {
1306 debug_flush(id, DEBUG_FLUSH_ALL);
1307 goto out;
1308 }
1309 if (isdigit(input_buf[0])) {
1310 int area = ((int) input_buf[0] - (int) '0');
1311
1312 debug_flush(id, area);
1313 goto out;
1314 }
1315
1316 pr_info("Flushing debug data failed because %c is not a valid "
1317 "area\n", input_buf[0]);
1318
1319out:
1320 *offset += user_len;
1321 return rc; /* number of input characters */
1322}
1323
1324/*
1325 * prints debug header in raw format
1326 */
1327static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1328 int area, debug_entry_t *entry, char *out_buf)
1329{
1330 int rc;
1331
1332 rc = sizeof(debug_entry_t);
1333 memcpy(out_buf, entry, sizeof(debug_entry_t));
1334 return rc;
1335}
1336
1337/*
1338 * prints debug data in raw format
1339 */
1340static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1341 char *out_buf, const char *in_buf)
1342{
1343 int rc;
1344
1345 rc = id->buf_size;
1346 memcpy(out_buf, in_buf, id->buf_size);
1347 return rc;
1348}
1349
1350/*
1351 * prints debug data in hex/ascii format
1352 */
1353static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1354 char *out_buf, const char *in_buf)
1355{
1356 int i, rc = 0;
1357
1358 for (i = 0; i < id->buf_size; i++)
1359 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1360 rc += sprintf(out_buf + rc, "| ");
1361 for (i = 0; i < id->buf_size; i++) {
1362 unsigned char c = in_buf[i];
1363
1364 if (isascii(c) && isprint(c))
1365 rc += sprintf(out_buf + rc, "%c", c);
1366 else
1367 rc += sprintf(out_buf + rc, ".");
1368 }
1369 rc += sprintf(out_buf + rc, "\n");
1370 return rc;
1371}
1372
1373/*
1374 * prints header for debug entry
1375 */
1376int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1377 int area, debug_entry_t *entry, char *out_buf)
1378{
1379 unsigned long base, sec, usec;
1380 unsigned long caller;
1381 unsigned int level;
1382 char *except_str;
1383 int rc = 0;
1384
1385 level = entry->id.fields.level;
1386 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1387 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1388 usec = do_div(sec, USEC_PER_SEC);
1389
1390 if (entry->id.fields.exception)
1391 except_str = "*";
1392 else
1393 except_str = "-";
1394 caller = (unsigned long) entry->caller;
1395 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1396 area, sec, usec, level, except_str,
1397 entry->id.fields.cpuid, (void *)caller);
1398 return rc;
1399}
1400EXPORT_SYMBOL(debug_dflt_header_fn);
1401
1402/*
1403 * prints debug data sprintf-formated:
1404 * debug_sprinf_event/exception calls must be used together with this view
1405 */
1406
1407#define DEBUG_SPRINTF_MAX_ARGS 10
1408
1409static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1410 char *out_buf, debug_sprintf_entry_t *curr_event)
1411{
1412 int num_longs, num_used_args = 0, i, rc = 0;
1413 int index[DEBUG_SPRINTF_MAX_ARGS];
1414
1415 /* count of longs fit into one entry */
1416 num_longs = id->buf_size / sizeof(long);
1417
1418 if (num_longs < 1)
1419 goto out; /* bufsize of entry too small */
1420 if (num_longs == 1) {
1421 /* no args, we use only the string */
1422 strcpy(out_buf, curr_event->string);
1423 rc = strlen(curr_event->string);
1424 goto out;
1425 }
1426
1427 /* number of arguments used for sprintf (without the format string) */
1428 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1429
1430 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1431
1432 for (i = 0; i < num_used_args; i++)
1433 index[i] = i;
1434
1435 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1436 curr_event->args[index[1]], curr_event->args[index[2]],
1437 curr_event->args[index[3]], curr_event->args[index[4]],
1438 curr_event->args[index[5]], curr_event->args[index[6]],
1439 curr_event->args[index[7]], curr_event->args[index[8]],
1440 curr_event->args[index[9]]);
1441out:
1442 return rc;
1443}
1444
1445/*
1446 * debug_init:
1447 * - is called exactly once to initialize the debug feature
1448 */
1449static int __init debug_init(void)
1450{
1451 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1452 mutex_lock(&debug_mutex);
1453 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1454 initialized = 1;
1455 mutex_unlock(&debug_mutex);
1456 return 0;
1457}
1458postcore_initcall(debug_init);
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 <linux/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
37typedef 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
53typedef 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
68static int debug_init(void);
69static ssize_t debug_output(struct file *file, char __user *user_buf,
70 size_t user_len, loff_t * offset);
71static ssize_t debug_input(struct file *file, const char __user *user_buf,
72 size_t user_len, loff_t * offset);
73static int debug_open(struct inode *inode, struct file *file);
74static int debug_close(struct inode *inode, struct file *file);
75static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76 int nr_areas, int buf_size, umode_t mode);
77static void debug_info_get(debug_info_t *);
78static void debug_info_put(debug_info_t *);
79static int debug_prolog_level_fn(debug_info_t * id,
80 struct debug_view *view, char *out_buf);
81static 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);
84static int debug_prolog_pages_fn(debug_info_t * id,
85 struct debug_view *view, char *out_buf);
86static 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);
89static 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);
92static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93 char *out_buf, const char *in_buf);
94static int debug_raw_format_fn(debug_info_t * id,
95 struct debug_view *view, char *out_buf,
96 const char *in_buf);
97static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98 int area, debug_entry_t * entry, char *out_buf);
99
100static 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
105struct debug_view debug_raw_view = {
106 "raw",
107 NULL,
108 &debug_raw_header_fn,
109 &debug_raw_format_fn,
110 NULL,
111 NULL
112};
113EXPORT_SYMBOL(debug_raw_view);
114
115struct 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};
123EXPORT_SYMBOL(debug_hex_ascii_view);
124
125static 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
134static 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
143static struct debug_view debug_flush_view = {
144 "flush",
145 NULL,
146 NULL,
147 NULL,
148 &debug_input_flush_fn,
149 NULL
150};
151
152struct 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};
160EXPORT_SYMBOL(debug_sprintf_view);
161
162/* used by dump analysis tools to determine version of debug feature */
163static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
164
165/* static globals */
166
167static debug_info_t *debug_area_first = NULL;
168static debug_info_t *debug_area_last = NULL;
169static DEFINE_MUTEX(debug_mutex);
170
171static int initialized;
172static int debug_critical;
173
174static 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
183static 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
193static debug_entry_t***
194debug_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
223fail_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);
231fail_malloc_areas:
232 return NULL;
233
234}
235
236
237/*
238 * debug_info_alloc
239 * - alloc new debug-info
240 */
241
242static debug_info_t*
243debug_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
284fail_malloc_areas:
285 kfree(rc->active_pages);
286fail_malloc_active_pages:
287 kfree(rc->active_entries);
288fail_malloc_active_entries:
289 kfree(rc);
290fail_malloc_rc:
291 return NULL;
292}
293
294/*
295 * debug_areas_free
296 * - free all debug areas
297 */
298
299static void
300debug_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
321static void
322debug_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
334static debug_info_t*
335debug_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);
365out:
366 return rc;
367}
368
369/*
370 * debug_info_copy
371 * - copy debug-info
372 */
373
374static debug_info_t*
375debug_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 }
405out:
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
415static void
416debug_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
427static void
428debug_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
456static int
457debug_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));
482out:
483 return len;
484}
485
486/*
487 * debug_next_entry:
488 * - goto next entry in p_info
489 */
490
491static inline int
492debug_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 }
518out:
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
528static ssize_t
529debug_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 }
567out:
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
580static ssize_t
581debug_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
606static int
607debug_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
628found:
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);
663out:
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
674static int
675debug_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
693debug_info_t *debug_register_mode(const char *name, int pages_per_area,
694 int nr_areas, int buf_size, umode_t mode,
695 uid_t uid, gid_t gid)
696{
697 debug_info_t *rc = NULL;
698
699 /* Since debugfs currently does not support uid/gid other than root, */
700 /* we do not allow gid/uid != 0 until we get support for that. */
701 if ((uid != 0) || (gid != 0))
702 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
703 BUG_ON(!initialized);
704 mutex_lock(&debug_mutex);
705
706 /* create new debug_info */
707
708 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
709 if(!rc)
710 goto out;
711 debug_register_view(rc, &debug_level_view);
712 debug_register_view(rc, &debug_flush_view);
713 debug_register_view(rc, &debug_pages_view);
714out:
715 if (!rc){
716 pr_err("Registering debug feature %s failed\n", name);
717 }
718 mutex_unlock(&debug_mutex);
719 return rc;
720}
721EXPORT_SYMBOL(debug_register_mode);
722
723/*
724 * debug_register:
725 * - creates and initializes debug area for the caller
726 * - returns handle for debug area
727 */
728
729debug_info_t *debug_register(const char *name, int pages_per_area,
730 int nr_areas, int buf_size)
731{
732 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
733 S_IRUSR | S_IWUSR, 0, 0);
734}
735EXPORT_SYMBOL(debug_register);
736
737/*
738 * debug_unregister:
739 * - give back debug area
740 */
741
742void
743debug_unregister(debug_info_t * id)
744{
745 if (!id)
746 goto out;
747 mutex_lock(&debug_mutex);
748 debug_info_put(id);
749 mutex_unlock(&debug_mutex);
750
751out:
752 return;
753}
754EXPORT_SYMBOL(debug_unregister);
755
756/*
757 * debug_set_size:
758 * - set area size (number of pages) and number of areas
759 */
760static int
761debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
762{
763 unsigned long flags;
764 debug_entry_t *** new_areas;
765 int rc=0;
766
767 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
768 return -EINVAL;
769 if(pages_per_area > 0){
770 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
771 if(!new_areas) {
772 pr_info("Allocating memory for %i pages failed\n",
773 pages_per_area);
774 rc = -ENOMEM;
775 goto out;
776 }
777 } else {
778 new_areas = NULL;
779 }
780 spin_lock_irqsave(&id->lock,flags);
781 debug_areas_free(id);
782 id->areas = new_areas;
783 id->nr_areas = nr_areas;
784 id->pages_per_area = pages_per_area;
785 id->active_area = 0;
786 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
787 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
788 spin_unlock_irqrestore(&id->lock,flags);
789 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
790out:
791 return rc;
792}
793
794/*
795 * debug_set_level:
796 * - set actual debug level
797 */
798
799void
800debug_set_level(debug_info_t* id, int new_level)
801{
802 unsigned long flags;
803 if(!id)
804 return;
805 spin_lock_irqsave(&id->lock,flags);
806 if(new_level == DEBUG_OFF_LEVEL){
807 id->level = DEBUG_OFF_LEVEL;
808 pr_info("%s: switched off\n",id->name);
809 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
810 pr_info("%s: level %i is out of range (%i - %i)\n",
811 id->name, new_level, 0, DEBUG_MAX_LEVEL);
812 } else {
813 id->level = new_level;
814 }
815 spin_unlock_irqrestore(&id->lock,flags);
816}
817EXPORT_SYMBOL(debug_set_level);
818
819/*
820 * proceed_active_entry:
821 * - set active entry to next in the ring buffer
822 */
823
824static inline void
825proceed_active_entry(debug_info_t * id)
826{
827 if ((id->active_entries[id->active_area] += id->entry_size)
828 > (PAGE_SIZE - id->entry_size)){
829 id->active_entries[id->active_area] = 0;
830 id->active_pages[id->active_area] =
831 (id->active_pages[id->active_area] + 1) %
832 id->pages_per_area;
833 }
834}
835
836/*
837 * proceed_active_area:
838 * - set active area to next in the ring buffer
839 */
840
841static inline void
842proceed_active_area(debug_info_t * id)
843{
844 id->active_area++;
845 id->active_area = id->active_area % id->nr_areas;
846}
847
848/*
849 * get_active_entry:
850 */
851
852static inline debug_entry_t*
853get_active_entry(debug_info_t * id)
854{
855 return (debug_entry_t *) (((char *) id->areas[id->active_area]
856 [id->active_pages[id->active_area]]) +
857 id->active_entries[id->active_area]);
858}
859
860/*
861 * debug_finish_entry:
862 * - set timestamp, caller address, cpu number etc.
863 */
864
865static inline void
866debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
867 int exception)
868{
869 active->id.stck = get_tod_clock_fast();
870 active->id.fields.cpuid = smp_processor_id();
871 active->caller = __builtin_return_address(0);
872 active->id.fields.exception = exception;
873 active->id.fields.level = level;
874 proceed_active_entry(id);
875 if(exception)
876 proceed_active_area(id);
877}
878
879static int debug_stoppable=1;
880static int debug_active=1;
881
882#define CTL_S390DBF_STOPPABLE 5678
883#define CTL_S390DBF_ACTIVE 5679
884
885/*
886 * proc handler for the running debug_active sysctl
887 * always allow read, allow write only if debug_stoppable is set or
888 * if debug_active is already off
889 */
890static int
891s390dbf_procactive(struct ctl_table *table, int write,
892 void __user *buffer, size_t *lenp, loff_t *ppos)
893{
894 if (!write || debug_stoppable || !debug_active)
895 return proc_dointvec(table, write, buffer, lenp, ppos);
896 else
897 return 0;
898}
899
900
901static struct ctl_table s390dbf_table[] = {
902 {
903 .procname = "debug_stoppable",
904 .data = &debug_stoppable,
905 .maxlen = sizeof(int),
906 .mode = S_IRUGO | S_IWUSR,
907 .proc_handler = proc_dointvec,
908 },
909 {
910 .procname = "debug_active",
911 .data = &debug_active,
912 .maxlen = sizeof(int),
913 .mode = S_IRUGO | S_IWUSR,
914 .proc_handler = s390dbf_procactive,
915 },
916 { }
917};
918
919static struct ctl_table s390dbf_dir_table[] = {
920 {
921 .procname = "s390dbf",
922 .maxlen = 0,
923 .mode = S_IRUGO | S_IXUGO,
924 .child = s390dbf_table,
925 },
926 { }
927};
928
929static struct ctl_table_header *s390dbf_sysctl_header;
930
931void
932debug_stop_all(void)
933{
934 if (debug_stoppable)
935 debug_active = 0;
936}
937EXPORT_SYMBOL(debug_stop_all);
938
939void debug_set_critical(void)
940{
941 debug_critical = 1;
942}
943
944/*
945 * debug_event_common:
946 * - write debug entry with given size
947 */
948
949debug_entry_t*
950debug_event_common(debug_info_t * id, int level, const void *buf, int len)
951{
952 unsigned long flags;
953 debug_entry_t *active;
954
955 if (!debug_active || !id->areas)
956 return NULL;
957 if (debug_critical) {
958 if (!spin_trylock_irqsave(&id->lock, flags))
959 return NULL;
960 } else
961 spin_lock_irqsave(&id->lock, flags);
962 active = get_active_entry(id);
963 memset(DEBUG_DATA(active), 0, id->buf_size);
964 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
965 debug_finish_entry(id, active, level, 0);
966 spin_unlock_irqrestore(&id->lock, flags);
967
968 return active;
969}
970EXPORT_SYMBOL(debug_event_common);
971
972/*
973 * debug_exception_common:
974 * - write debug entry with given size and switch to next debug area
975 */
976
977debug_entry_t
978*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
979{
980 unsigned long flags;
981 debug_entry_t *active;
982
983 if (!debug_active || !id->areas)
984 return NULL;
985 if (debug_critical) {
986 if (!spin_trylock_irqsave(&id->lock, flags))
987 return NULL;
988 } else
989 spin_lock_irqsave(&id->lock, flags);
990 active = get_active_entry(id);
991 memset(DEBUG_DATA(active), 0, id->buf_size);
992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
993 debug_finish_entry(id, active, level, 1);
994 spin_unlock_irqrestore(&id->lock, flags);
995
996 return active;
997}
998EXPORT_SYMBOL(debug_exception_common);
999
1000/*
1001 * counts arguments in format string for sprintf view
1002 */
1003
1004static inline int
1005debug_count_numargs(char *string)
1006{
1007 int numargs=0;
1008
1009 while(*string) {
1010 if(*string++=='%')
1011 numargs++;
1012 }
1013 return(numargs);
1014}
1015
1016/*
1017 * debug_sprintf_event:
1018 */
1019
1020debug_entry_t*
1021__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1022{
1023 va_list ap;
1024 int numargs,idx;
1025 unsigned long flags;
1026 debug_sprintf_entry_t *curr_event;
1027 debug_entry_t *active;
1028
1029 if (!debug_active || !id->areas)
1030 return NULL;
1031 numargs=debug_count_numargs(string);
1032
1033 if (debug_critical) {
1034 if (!spin_trylock_irqsave(&id->lock, flags))
1035 return NULL;
1036 } else
1037 spin_lock_irqsave(&id->lock, flags);
1038 active = get_active_entry(id);
1039 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1040 va_start(ap,string);
1041 curr_event->string=string;
1042 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1043 curr_event->args[idx]=va_arg(ap,long);
1044 va_end(ap);
1045 debug_finish_entry(id, active, level, 0);
1046 spin_unlock_irqrestore(&id->lock, flags);
1047
1048 return active;
1049}
1050EXPORT_SYMBOL(__debug_sprintf_event);
1051
1052/*
1053 * debug_sprintf_exception:
1054 */
1055
1056debug_entry_t*
1057__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1058{
1059 va_list ap;
1060 int numargs,idx;
1061 unsigned long flags;
1062 debug_sprintf_entry_t *curr_event;
1063 debug_entry_t *active;
1064
1065 if (!debug_active || !id->areas)
1066 return NULL;
1067
1068 numargs=debug_count_numargs(string);
1069
1070 if (debug_critical) {
1071 if (!spin_trylock_irqsave(&id->lock, flags))
1072 return NULL;
1073 } else
1074 spin_lock_irqsave(&id->lock, flags);
1075 active = get_active_entry(id);
1076 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1077 va_start(ap,string);
1078 curr_event->string=string;
1079 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1080 curr_event->args[idx]=va_arg(ap,long);
1081 va_end(ap);
1082 debug_finish_entry(id, active, level, 1);
1083 spin_unlock_irqrestore(&id->lock, flags);
1084
1085 return active;
1086}
1087EXPORT_SYMBOL(__debug_sprintf_exception);
1088
1089/*
1090 * debug_register_view:
1091 */
1092
1093int
1094debug_register_view(debug_info_t * id, struct debug_view *view)
1095{
1096 int rc = 0;
1097 int i;
1098 unsigned long flags;
1099 umode_t mode;
1100 struct dentry *pde;
1101
1102 if (!id)
1103 goto out;
1104 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1105 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1106 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1107 if (!view->input_proc)
1108 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1109 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1110 id , &debug_file_ops);
1111 if (!pde){
1112 pr_err("Registering view %s/%s failed due to out of "
1113 "memory\n", id->name,view->name);
1114 rc = -1;
1115 goto out;
1116 }
1117 spin_lock_irqsave(&id->lock, flags);
1118 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1119 if (!id->views[i])
1120 break;
1121 }
1122 if (i == DEBUG_MAX_VIEWS) {
1123 pr_err("Registering view %s/%s would exceed the maximum "
1124 "number of views %i\n", id->name, view->name, i);
1125 rc = -1;
1126 } else {
1127 id->views[i] = view;
1128 id->debugfs_entries[i] = pde;
1129 }
1130 spin_unlock_irqrestore(&id->lock, flags);
1131 if (rc)
1132 debugfs_remove(pde);
1133out:
1134 return rc;
1135}
1136EXPORT_SYMBOL(debug_register_view);
1137
1138/*
1139 * debug_unregister_view:
1140 */
1141
1142int
1143debug_unregister_view(debug_info_t * id, struct debug_view *view)
1144{
1145 struct dentry *dentry = NULL;
1146 unsigned long flags;
1147 int i, rc = 0;
1148
1149 if (!id)
1150 goto out;
1151 spin_lock_irqsave(&id->lock, flags);
1152 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1153 if (id->views[i] == view)
1154 break;
1155 }
1156 if (i == DEBUG_MAX_VIEWS)
1157 rc = -1;
1158 else {
1159 dentry = id->debugfs_entries[i];
1160 id->views[i] = NULL;
1161 id->debugfs_entries[i] = NULL;
1162 }
1163 spin_unlock_irqrestore(&id->lock, flags);
1164 debugfs_remove(dentry);
1165out:
1166 return rc;
1167}
1168EXPORT_SYMBOL(debug_unregister_view);
1169
1170static inline char *
1171debug_get_user_string(const char __user *user_buf, size_t user_len)
1172{
1173 char* buffer;
1174
1175 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1176 if (!buffer)
1177 return ERR_PTR(-ENOMEM);
1178 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1179 kfree(buffer);
1180 return ERR_PTR(-EFAULT);
1181 }
1182 /* got the string, now strip linefeed. */
1183 if (buffer[user_len - 1] == '\n')
1184 buffer[user_len - 1] = 0;
1185 else
1186 buffer[user_len] = 0;
1187 return buffer;
1188}
1189
1190static inline int
1191debug_get_uint(char *buf)
1192{
1193 int rc;
1194
1195 buf = skip_spaces(buf);
1196 rc = simple_strtoul(buf, &buf, 10);
1197 if(*buf){
1198 rc = -EINVAL;
1199 }
1200 return rc;
1201}
1202
1203/*
1204 * functions for debug-views
1205 ***********************************
1206*/
1207
1208/*
1209 * prints out actual debug level
1210 */
1211
1212static int
1213debug_prolog_pages_fn(debug_info_t * id,
1214 struct debug_view *view, char *out_buf)
1215{
1216 return sprintf(out_buf, "%i\n", id->pages_per_area);
1217}
1218
1219/*
1220 * reads new size (number of pages per debug area)
1221 */
1222
1223static int
1224debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1225 struct file *file, const char __user *user_buf,
1226 size_t user_len, loff_t * offset)
1227{
1228 char *str;
1229 int rc,new_pages;
1230
1231 if (user_len > 0x10000)
1232 user_len = 0x10000;
1233 if (*offset != 0){
1234 rc = -EPIPE;
1235 goto out;
1236 }
1237 str = debug_get_user_string(user_buf,user_len);
1238 if(IS_ERR(str)){
1239 rc = PTR_ERR(str);
1240 goto out;
1241 }
1242 new_pages = debug_get_uint(str);
1243 if(new_pages < 0){
1244 rc = -EINVAL;
1245 goto free_str;
1246 }
1247 rc = debug_set_size(id,id->nr_areas, new_pages);
1248 if(rc != 0){
1249 rc = -EINVAL;
1250 goto free_str;
1251 }
1252 rc = user_len;
1253free_str:
1254 kfree(str);
1255out:
1256 *offset += user_len;
1257 return rc; /* number of input characters */
1258}
1259
1260/*
1261 * prints out actual debug level
1262 */
1263
1264static int
1265debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1266{
1267 int rc = 0;
1268
1269 if(id->level == DEBUG_OFF_LEVEL) {
1270 rc = sprintf(out_buf,"-\n");
1271 }
1272 else {
1273 rc = sprintf(out_buf, "%i\n", id->level);
1274 }
1275 return rc;
1276}
1277
1278/*
1279 * reads new debug level
1280 */
1281
1282static int
1283debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1284 struct file *file, const char __user *user_buf,
1285 size_t user_len, loff_t * offset)
1286{
1287 char *str;
1288 int rc,new_level;
1289
1290 if (user_len > 0x10000)
1291 user_len = 0x10000;
1292 if (*offset != 0){
1293 rc = -EPIPE;
1294 goto out;
1295 }
1296 str = debug_get_user_string(user_buf,user_len);
1297 if(IS_ERR(str)){
1298 rc = PTR_ERR(str);
1299 goto out;
1300 }
1301 if(str[0] == '-'){
1302 debug_set_level(id, DEBUG_OFF_LEVEL);
1303 rc = user_len;
1304 goto free_str;
1305 } else {
1306 new_level = debug_get_uint(str);
1307 }
1308 if(new_level < 0) {
1309 pr_warn("%s is not a valid level for a debug feature\n", str);
1310 rc = -EINVAL;
1311 } else {
1312 debug_set_level(id, new_level);
1313 rc = user_len;
1314 }
1315free_str:
1316 kfree(str);
1317out:
1318 *offset += user_len;
1319 return rc; /* number of input characters */
1320}
1321
1322
1323/*
1324 * flushes debug areas
1325 */
1326
1327static void debug_flush(debug_info_t* id, int area)
1328{
1329 unsigned long flags;
1330 int i,j;
1331
1332 if(!id || !id->areas)
1333 return;
1334 spin_lock_irqsave(&id->lock,flags);
1335 if(area == DEBUG_FLUSH_ALL){
1336 id->active_area = 0;
1337 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1338 for (i = 0; i < id->nr_areas; i++) {
1339 id->active_pages[i] = 0;
1340 for(j = 0; j < id->pages_per_area; j++) {
1341 memset(id->areas[i][j], 0, PAGE_SIZE);
1342 }
1343 }
1344 } else if(area >= 0 && area < id->nr_areas) {
1345 id->active_entries[area] = 0;
1346 id->active_pages[area] = 0;
1347 for(i = 0; i < id->pages_per_area; i++) {
1348 memset(id->areas[area][i],0,PAGE_SIZE);
1349 }
1350 }
1351 spin_unlock_irqrestore(&id->lock,flags);
1352}
1353
1354/*
1355 * view function: flushes debug areas
1356 */
1357
1358static int
1359debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1360 struct file *file, const char __user *user_buf,
1361 size_t user_len, loff_t * offset)
1362{
1363 char input_buf[1];
1364 int rc = user_len;
1365
1366 if (user_len > 0x10000)
1367 user_len = 0x10000;
1368 if (*offset != 0){
1369 rc = -EPIPE;
1370 goto out;
1371 }
1372 if (copy_from_user(input_buf, user_buf, 1)){
1373 rc = -EFAULT;
1374 goto out;
1375 }
1376 if(input_buf[0] == '-') {
1377 debug_flush(id, DEBUG_FLUSH_ALL);
1378 goto out;
1379 }
1380 if (isdigit(input_buf[0])) {
1381 int area = ((int) input_buf[0] - (int) '0');
1382 debug_flush(id, area);
1383 goto out;
1384 }
1385
1386 pr_info("Flushing debug data failed because %c is not a valid "
1387 "area\n", input_buf[0]);
1388
1389out:
1390 *offset += user_len;
1391 return rc; /* number of input characters */
1392}
1393
1394/*
1395 * prints debug header in raw format
1396 */
1397
1398static int
1399debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1400 int area, debug_entry_t * entry, char *out_buf)
1401{
1402 int rc;
1403
1404 rc = sizeof(debug_entry_t);
1405 memcpy(out_buf,entry,sizeof(debug_entry_t));
1406 return rc;
1407}
1408
1409/*
1410 * prints debug data in raw format
1411 */
1412
1413static int
1414debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1415 char *out_buf, const char *in_buf)
1416{
1417 int rc;
1418
1419 rc = id->buf_size;
1420 memcpy(out_buf, in_buf, id->buf_size);
1421 return rc;
1422}
1423
1424/*
1425 * prints debug data in hex/ascii format
1426 */
1427
1428static int
1429debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1430 char *out_buf, const char *in_buf)
1431{
1432 int i, rc = 0;
1433
1434 for (i = 0; i < id->buf_size; i++) {
1435 rc += sprintf(out_buf + rc, "%02x ",
1436 ((unsigned char *) in_buf)[i]);
1437 }
1438 rc += sprintf(out_buf + rc, "| ");
1439 for (i = 0; i < id->buf_size; i++) {
1440 unsigned char c = in_buf[i];
1441 if (isascii(c) && isprint(c))
1442 rc += sprintf(out_buf + rc, "%c", c);
1443 else
1444 rc += sprintf(out_buf + rc, ".");
1445 }
1446 rc += sprintf(out_buf + rc, "\n");
1447 return rc;
1448}
1449
1450/*
1451 * prints header for debug entry
1452 */
1453
1454int
1455debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1456 int area, debug_entry_t * entry, char *out_buf)
1457{
1458 struct timespec64 time_spec;
1459 char *except_str;
1460 unsigned long caller;
1461 int rc = 0;
1462 unsigned int level;
1463
1464 level = entry->id.fields.level;
1465 stck_to_timespec64(entry->id.stck, &time_spec);
1466
1467 if (entry->id.fields.exception)
1468 except_str = "*";
1469 else
1470 except_str = "-";
1471 caller = (unsigned long) entry->caller;
1472 rc += sprintf(out_buf, "%02i %011lld:%06lu %1u %1s %02i %p ",
1473 area, (long long)time_spec.tv_sec,
1474 time_spec.tv_nsec / 1000, level, except_str,
1475 entry->id.fields.cpuid, (void *)caller);
1476 return rc;
1477}
1478EXPORT_SYMBOL(debug_dflt_header_fn);
1479
1480/*
1481 * prints debug data sprintf-formated:
1482 * debug_sprinf_event/exception calls must be used together with this view
1483 */
1484
1485#define DEBUG_SPRINTF_MAX_ARGS 10
1486
1487static int
1488debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1489 char *out_buf, debug_sprintf_entry_t *curr_event)
1490{
1491 int num_longs, num_used_args = 0,i, rc = 0;
1492 int index[DEBUG_SPRINTF_MAX_ARGS];
1493
1494 /* count of longs fit into one entry */
1495 num_longs = id->buf_size / sizeof(long);
1496
1497 if(num_longs < 1)
1498 goto out; /* bufsize of entry too small */
1499 if(num_longs == 1) {
1500 /* no args, we use only the string */
1501 strcpy(out_buf, curr_event->string);
1502 rc = strlen(curr_event->string);
1503 goto out;
1504 }
1505
1506 /* number of arguments used for sprintf (without the format string) */
1507 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1508
1509 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1510
1511 for(i = 0; i < num_used_args; i++)
1512 index[i] = i;
1513
1514 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1515 curr_event->args[index[1]], curr_event->args[index[2]],
1516 curr_event->args[index[3]], curr_event->args[index[4]],
1517 curr_event->args[index[5]], curr_event->args[index[6]],
1518 curr_event->args[index[7]], curr_event->args[index[8]],
1519 curr_event->args[index[9]]);
1520
1521out:
1522
1523 return rc;
1524}
1525
1526/*
1527 * debug_init:
1528 * - is called exactly once to initialize the debug feature
1529 */
1530static int __init debug_init(void)
1531{
1532 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1533 mutex_lock(&debug_mutex);
1534 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1535 initialized = 1;
1536 mutex_unlock(&debug_mutex);
1537 return 0;
1538}
1539postcore_initcall(debug_init);