Loading...
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_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
218fail_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);
225fail_malloc_areas:
226 return NULL;
227}
228
229/*
230 * debug_info_alloc
231 * - alloc new debug-info
232 */
233static 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
272fail_malloc_areas:
273 kfree(rc->active_pages);
274fail_malloc_active_pages:
275 kfree(rc->active_entries);
276fail_malloc_active_entries:
277 kfree(rc);
278fail_malloc_rc:
279 return NULL;
280}
281
282/*
283 * debug_areas_free
284 * - free all debug areas
285 */
286static 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 */
305static 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
318static 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);
348out:
349 return rc;
350}
351
352/*
353 * debug_info_copy
354 * - copy debug-info
355 */
356static 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 }
385out:
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 */
394static 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 */
404static 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 */
433static 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));
459out:
460 return len;
461}
462
463/*
464 * debug_next_entry:
465 * - goto next entry in p_info
466 */
467static 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 }
493out:
494 return 0;
495}
496
497/*
498 * debug_output:
499 * - called for user read()
500 * - copies formated debug entries to the user buffer
501 */
502static 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 }
540out:
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 */
552static 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 */
577static 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
596found:
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);
628out:
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 */
638static 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() - creates and initializes debug area.
652 *
653 * @name: Name of debug log (e.g. used for debugfs entry)
654 * @pages_per_area: Number of pages, which will be allocated per area
655 * @nr_areas: Number of debug areas
656 * @buf_size: Size of data area in each debug entry
657 * @mode: File mode for debugfs files. E.g. S_IRWXUGO
658 * @uid: User ID for debugfs files. Currently only 0 is supported.
659 * @gid: Group ID for debugfs files. Currently only 0 is supported.
660 *
661 * Return:
662 * - Handle for generated debug area
663 * - %NULL if register failed
664 *
665 * Allocates memory for a debug log.
666 * Must not be called within an interrupt handler.
667 */
668debug_info_t *debug_register_mode(const char *name, int pages_per_area,
669 int nr_areas, int buf_size, umode_t mode,
670 uid_t uid, gid_t gid)
671{
672 debug_info_t *rc = NULL;
673
674 /* Since debugfs currently does not support uid/gid other than root, */
675 /* we do not allow gid/uid != 0 until we get support for that. */
676 if ((uid != 0) || (gid != 0))
677 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
678 BUG_ON(!initialized);
679 mutex_lock(&debug_mutex);
680
681 /* create new debug_info */
682 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
683 if (!rc)
684 goto out;
685 debug_register_view(rc, &debug_level_view);
686 debug_register_view(rc, &debug_flush_view);
687 debug_register_view(rc, &debug_pages_view);
688out:
689 if (!rc)
690 pr_err("Registering debug feature %s failed\n", name);
691 mutex_unlock(&debug_mutex);
692 return rc;
693}
694EXPORT_SYMBOL(debug_register_mode);
695
696/**
697 * debug_register() - creates and initializes debug area with default file mode.
698 *
699 * @name: Name of debug log (e.g. used for debugfs entry)
700 * @pages_per_area: Number of pages, which will be allocated per area
701 * @nr_areas: Number of debug areas
702 * @buf_size: Size of data area in each debug entry
703 *
704 * Return:
705 * - Handle for generated debug area
706 * - %NULL if register failed
707 *
708 * Allocates memory for a debug log.
709 * The debugfs file mode access permissions are read and write for user.
710 * Must not be called within an interrupt handler.
711 */
712debug_info_t *debug_register(const char *name, int pages_per_area,
713 int nr_areas, int buf_size)
714{
715 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
716 S_IRUSR | S_IWUSR, 0, 0);
717}
718EXPORT_SYMBOL(debug_register);
719
720/**
721 * debug_unregister() - give back debug area.
722 *
723 * @id: handle for debug log
724 *
725 * Return:
726 * none
727 */
728void debug_unregister(debug_info_t *id)
729{
730 if (!id)
731 return;
732 mutex_lock(&debug_mutex);
733 debug_info_put(id);
734 mutex_unlock(&debug_mutex);
735}
736EXPORT_SYMBOL(debug_unregister);
737
738/*
739 * debug_set_size:
740 * - set area size (number of pages) and number of areas
741 */
742static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
743{
744 debug_entry_t ***new_areas;
745 unsigned long flags;
746 int rc = 0;
747
748 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
749 return -EINVAL;
750 if (pages_per_area > 0) {
751 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
752 if (!new_areas) {
753 pr_info("Allocating memory for %i pages failed\n",
754 pages_per_area);
755 rc = -ENOMEM;
756 goto out;
757 }
758 } else {
759 new_areas = NULL;
760 }
761 spin_lock_irqsave(&id->lock, flags);
762 debug_areas_free(id);
763 id->areas = new_areas;
764 id->nr_areas = nr_areas;
765 id->pages_per_area = pages_per_area;
766 id->active_area = 0;
767 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
768 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
769 spin_unlock_irqrestore(&id->lock, flags);
770 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
771out:
772 return rc;
773}
774
775/**
776 * debug_set_level() - Sets new actual debug level if new_level is valid.
777 *
778 * @id: handle for debug log
779 * @new_level: new debug level
780 *
781 * Return:
782 * none
783 */
784void debug_set_level(debug_info_t *id, int new_level)
785{
786 unsigned long flags;
787
788 if (!id)
789 return;
790 spin_lock_irqsave(&id->lock, flags);
791 if (new_level == DEBUG_OFF_LEVEL) {
792 id->level = DEBUG_OFF_LEVEL;
793 pr_info("%s: switched off\n", id->name);
794 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
795 pr_info("%s: level %i is out of range (%i - %i)\n",
796 id->name, new_level, 0, DEBUG_MAX_LEVEL);
797 } else {
798 id->level = new_level;
799 }
800 spin_unlock_irqrestore(&id->lock, flags);
801}
802EXPORT_SYMBOL(debug_set_level);
803
804/*
805 * proceed_active_entry:
806 * - set active entry to next in the ring buffer
807 */
808static inline void proceed_active_entry(debug_info_t *id)
809{
810 if ((id->active_entries[id->active_area] += id->entry_size)
811 > (PAGE_SIZE - id->entry_size)) {
812 id->active_entries[id->active_area] = 0;
813 id->active_pages[id->active_area] =
814 (id->active_pages[id->active_area] + 1) %
815 id->pages_per_area;
816 }
817}
818
819/*
820 * proceed_active_area:
821 * - set active area to next in the ring buffer
822 */
823static inline void proceed_active_area(debug_info_t *id)
824{
825 id->active_area++;
826 id->active_area = id->active_area % id->nr_areas;
827}
828
829/*
830 * get_active_entry:
831 */
832static inline debug_entry_t *get_active_entry(debug_info_t *id)
833{
834 return (debug_entry_t *) (((char *) id->areas[id->active_area]
835 [id->active_pages[id->active_area]]) +
836 id->active_entries[id->active_area]);
837}
838
839/*
840 * debug_finish_entry:
841 * - set timestamp, caller address, cpu number etc.
842 */
843
844static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
845 int level, int exception)
846{
847 active->id.stck = get_tod_clock_fast() -
848 *(unsigned long long *) &tod_clock_base[1];
849 active->id.fields.cpuid = smp_processor_id();
850 active->caller = __builtin_return_address(0);
851 active->id.fields.exception = exception;
852 active->id.fields.level = level;
853 proceed_active_entry(id);
854 if (exception)
855 proceed_active_area(id);
856}
857
858static int debug_stoppable = 1;
859static int debug_active = 1;
860
861#define CTL_S390DBF_STOPPABLE 5678
862#define CTL_S390DBF_ACTIVE 5679
863
864/*
865 * proc handler for the running debug_active sysctl
866 * always allow read, allow write only if debug_stoppable is set or
867 * if debug_active is already off
868 */
869static int s390dbf_procactive(struct ctl_table *table, int write,
870 void __user *buffer, size_t *lenp, loff_t *ppos)
871{
872 if (!write || debug_stoppable || !debug_active)
873 return proc_dointvec(table, write, buffer, lenp, ppos);
874 else
875 return 0;
876}
877
878static struct ctl_table s390dbf_table[] = {
879 {
880 .procname = "debug_stoppable",
881 .data = &debug_stoppable,
882 .maxlen = sizeof(int),
883 .mode = S_IRUGO | S_IWUSR,
884 .proc_handler = proc_dointvec,
885 },
886 {
887 .procname = "debug_active",
888 .data = &debug_active,
889 .maxlen = sizeof(int),
890 .mode = S_IRUGO | S_IWUSR,
891 .proc_handler = s390dbf_procactive,
892 },
893 { }
894};
895
896static struct ctl_table s390dbf_dir_table[] = {
897 {
898 .procname = "s390dbf",
899 .maxlen = 0,
900 .mode = S_IRUGO | S_IXUGO,
901 .child = s390dbf_table,
902 },
903 { }
904};
905
906static struct ctl_table_header *s390dbf_sysctl_header;
907
908/**
909 * debug_stop_all() - stops the debug feature if stopping is allowed.
910 *
911 * Return:
912 * - none
913 *
914 * Currently used in case of a kernel oops.
915 */
916void debug_stop_all(void)
917{
918 if (debug_stoppable)
919 debug_active = 0;
920}
921EXPORT_SYMBOL(debug_stop_all);
922
923/**
924 * debug_set_critical() - event/exception functions try lock instead of spin.
925 *
926 * Return:
927 * - none
928 *
929 * Currently used in case of stopping all CPUs but the current one.
930 * Once in this state, functions to write a debug entry for an
931 * event or exception no longer spin on the debug area lock,
932 * but only try to get it and fail if they do not get the lock.
933 */
934void debug_set_critical(void)
935{
936 debug_critical = 1;
937}
938
939/*
940 * debug_event_common:
941 * - write debug entry with given size
942 */
943debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
944 int len)
945{
946 debug_entry_t *active;
947 unsigned long flags;
948
949 if (!debug_active || !id->areas)
950 return NULL;
951 if (debug_critical) {
952 if (!spin_trylock_irqsave(&id->lock, flags))
953 return NULL;
954 } else {
955 spin_lock_irqsave(&id->lock, flags);
956 }
957 do {
958 active = get_active_entry(id);
959 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
960 if (len < id->buf_size)
961 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
962 debug_finish_entry(id, active, level, 0);
963 len -= id->buf_size;
964 buf += id->buf_size;
965 } while (len > 0);
966
967 spin_unlock_irqrestore(&id->lock, flags);
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 */
976debug_entry_t *debug_exception_common(debug_info_t *id, int level,
977 const void *buf, int len)
978{
979 debug_entry_t *active;
980 unsigned long flags;
981
982 if (!debug_active || !id->areas)
983 return NULL;
984 if (debug_critical) {
985 if (!spin_trylock_irqsave(&id->lock, flags))
986 return NULL;
987 } else {
988 spin_lock_irqsave(&id->lock, flags);
989 }
990 do {
991 active = get_active_entry(id);
992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
993 if (len < id->buf_size)
994 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
995 debug_finish_entry(id, active, level, len <= id->buf_size);
996 len -= id->buf_size;
997 buf += id->buf_size;
998 } while (len > 0);
999
1000 spin_unlock_irqrestore(&id->lock, flags);
1001 return active;
1002}
1003EXPORT_SYMBOL(debug_exception_common);
1004
1005/*
1006 * counts arguments in format string for sprintf view
1007 */
1008static inline int debug_count_numargs(char *string)
1009{
1010 int numargs = 0;
1011
1012 while (*string) {
1013 if (*string++ == '%')
1014 numargs++;
1015 }
1016 return numargs;
1017}
1018
1019/*
1020 * debug_sprintf_event:
1021 */
1022debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1023{
1024 debug_sprintf_entry_t *curr_event;
1025 debug_entry_t *active;
1026 unsigned long flags;
1027 int numargs, idx;
1028 va_list ap;
1029
1030 if (!debug_active || !id->areas)
1031 return NULL;
1032 numargs = debug_count_numargs(string);
1033
1034 if (debug_critical) {
1035 if (!spin_trylock_irqsave(&id->lock, flags))
1036 return NULL;
1037 } else {
1038 spin_lock_irqsave(&id->lock, flags);
1039 }
1040 active = get_active_entry(id);
1041 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1042 va_start(ap, string);
1043 curr_event->string = string;
1044 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1045 curr_event->args[idx] = va_arg(ap, long);
1046 va_end(ap);
1047 debug_finish_entry(id, active, level, 0);
1048 spin_unlock_irqrestore(&id->lock, flags);
1049
1050 return active;
1051}
1052EXPORT_SYMBOL(__debug_sprintf_event);
1053
1054/*
1055 * debug_sprintf_exception:
1056 */
1057debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1058{
1059 debug_sprintf_entry_t *curr_event;
1060 debug_entry_t *active;
1061 unsigned long flags;
1062 int numargs, idx;
1063 va_list ap;
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 }
1076 active = get_active_entry(id);
1077 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1078 va_start(ap, string);
1079 curr_event->string = string;
1080 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1081 curr_event->args[idx] = va_arg(ap, long);
1082 va_end(ap);
1083 debug_finish_entry(id, active, level, 1);
1084 spin_unlock_irqrestore(&id->lock, flags);
1085
1086 return active;
1087}
1088EXPORT_SYMBOL(__debug_sprintf_exception);
1089
1090/**
1091 * debug_register_view() - registers new debug view and creates debugfs
1092 * dir entry
1093 *
1094 * @id: handle for debug log
1095 * @view: pointer to debug view struct
1096 *
1097 * Return:
1098 * - 0 : ok
1099 * - < 0: Error
1100 */
1101int debug_register_view(debug_info_t *id, struct debug_view *view)
1102{
1103 unsigned long flags;
1104 struct dentry *pde;
1105 umode_t mode;
1106 int rc = 0;
1107 int i;
1108
1109 if (!id)
1110 goto out;
1111 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1112 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1113 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1114 if (!view->input_proc)
1115 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1116 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1117 id, &debug_file_ops);
1118 spin_lock_irqsave(&id->lock, flags);
1119 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1120 if (!id->views[i])
1121 break;
1122 }
1123 if (i == DEBUG_MAX_VIEWS) {
1124 pr_err("Registering view %s/%s would exceed the maximum "
1125 "number of views %i\n", id->name, view->name, i);
1126 rc = -1;
1127 } else {
1128 id->views[i] = view;
1129 id->debugfs_entries[i] = pde;
1130 }
1131 spin_unlock_irqrestore(&id->lock, flags);
1132 if (rc)
1133 debugfs_remove(pde);
1134out:
1135 return rc;
1136}
1137EXPORT_SYMBOL(debug_register_view);
1138
1139/**
1140 * debug_unregister_view() - unregisters debug view and removes debugfs
1141 * dir entry
1142 *
1143 * @id: handle for debug log
1144 * @view: pointer to debug view struct
1145 *
1146 * Return:
1147 * - 0 : ok
1148 * - < 0: Error
1149 */
1150int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1151{
1152 struct dentry *dentry = NULL;
1153 unsigned long flags;
1154 int i, rc = 0;
1155
1156 if (!id)
1157 goto out;
1158 spin_lock_irqsave(&id->lock, flags);
1159 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1160 if (id->views[i] == view)
1161 break;
1162 }
1163 if (i == DEBUG_MAX_VIEWS) {
1164 rc = -1;
1165 } else {
1166 dentry = id->debugfs_entries[i];
1167 id->views[i] = NULL;
1168 id->debugfs_entries[i] = NULL;
1169 }
1170 spin_unlock_irqrestore(&id->lock, flags);
1171 debugfs_remove(dentry);
1172out:
1173 return rc;
1174}
1175EXPORT_SYMBOL(debug_unregister_view);
1176
1177static inline char *debug_get_user_string(const char __user *user_buf,
1178 size_t user_len)
1179{
1180 char *buffer;
1181
1182 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1183 if (!buffer)
1184 return ERR_PTR(-ENOMEM);
1185 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1186 kfree(buffer);
1187 return ERR_PTR(-EFAULT);
1188 }
1189 /* got the string, now strip linefeed. */
1190 if (buffer[user_len - 1] == '\n')
1191 buffer[user_len - 1] = 0;
1192 else
1193 buffer[user_len] = 0;
1194 return buffer;
1195}
1196
1197static inline int debug_get_uint(char *buf)
1198{
1199 int rc;
1200
1201 buf = skip_spaces(buf);
1202 rc = simple_strtoul(buf, &buf, 10);
1203 if (*buf)
1204 rc = -EINVAL;
1205 return rc;
1206}
1207
1208/*
1209 * functions for debug-views
1210 ***********************************
1211*/
1212
1213/*
1214 * prints out actual debug level
1215 */
1216
1217static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1218 char *out_buf)
1219{
1220 return sprintf(out_buf, "%i\n", id->pages_per_area);
1221}
1222
1223/*
1224 * reads new size (number of pages per debug area)
1225 */
1226
1227static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1228 struct file *file, const char __user *user_buf,
1229 size_t user_len, loff_t *offset)
1230{
1231 int rc, new_pages;
1232 char *str;
1233
1234 if (user_len > 0x10000)
1235 user_len = 0x10000;
1236 if (*offset != 0) {
1237 rc = -EPIPE;
1238 goto out;
1239 }
1240 str = debug_get_user_string(user_buf, user_len);
1241 if (IS_ERR(str)) {
1242 rc = PTR_ERR(str);
1243 goto out;
1244 }
1245 new_pages = debug_get_uint(str);
1246 if (new_pages < 0) {
1247 rc = -EINVAL;
1248 goto free_str;
1249 }
1250 rc = debug_set_size(id, id->nr_areas, new_pages);
1251 if (rc != 0) {
1252 rc = -EINVAL;
1253 goto free_str;
1254 }
1255 rc = user_len;
1256free_str:
1257 kfree(str);
1258out:
1259 *offset += user_len;
1260 return rc; /* number of input characters */
1261}
1262
1263/*
1264 * prints out actual debug level
1265 */
1266static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1267 char *out_buf)
1268{
1269 int rc = 0;
1270
1271 if (id->level == DEBUG_OFF_LEVEL)
1272 rc = sprintf(out_buf, "-\n");
1273 else
1274 rc = sprintf(out_buf, "%i\n", id->level);
1275 return rc;
1276}
1277
1278/*
1279 * reads new debug level
1280 */
1281static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1282 struct file *file, const char __user *user_buf,
1283 size_t user_len, loff_t *offset)
1284{
1285 int rc, new_level;
1286 char *str;
1287
1288 if (user_len > 0x10000)
1289 user_len = 0x10000;
1290 if (*offset != 0) {
1291 rc = -EPIPE;
1292 goto out;
1293 }
1294 str = debug_get_user_string(user_buf, user_len);
1295 if (IS_ERR(str)) {
1296 rc = PTR_ERR(str);
1297 goto out;
1298 }
1299 if (str[0] == '-') {
1300 debug_set_level(id, DEBUG_OFF_LEVEL);
1301 rc = user_len;
1302 goto free_str;
1303 } else {
1304 new_level = debug_get_uint(str);
1305 }
1306 if (new_level < 0) {
1307 pr_warn("%s is not a valid level for a debug feature\n", str);
1308 rc = -EINVAL;
1309 } else {
1310 debug_set_level(id, new_level);
1311 rc = user_len;
1312 }
1313free_str:
1314 kfree(str);
1315out:
1316 *offset += user_len;
1317 return rc; /* number of input characters */
1318}
1319
1320/*
1321 * flushes debug areas
1322 */
1323static void debug_flush(debug_info_t *id, int area)
1324{
1325 unsigned long flags;
1326 int i, j;
1327
1328 if (!id || !id->areas)
1329 return;
1330 spin_lock_irqsave(&id->lock, flags);
1331 if (area == DEBUG_FLUSH_ALL) {
1332 id->active_area = 0;
1333 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1334 for (i = 0; i < id->nr_areas; i++) {
1335 id->active_pages[i] = 0;
1336 for (j = 0; j < id->pages_per_area; j++)
1337 memset(id->areas[i][j], 0, PAGE_SIZE);
1338 }
1339 } else if (area >= 0 && area < id->nr_areas) {
1340 id->active_entries[area] = 0;
1341 id->active_pages[area] = 0;
1342 for (i = 0; i < id->pages_per_area; i++)
1343 memset(id->areas[area][i], 0, PAGE_SIZE);
1344 }
1345 spin_unlock_irqrestore(&id->lock, flags);
1346}
1347
1348/*
1349 * view function: flushes debug areas
1350 */
1351static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1352 struct file *file, const char __user *user_buf,
1353 size_t user_len, loff_t *offset)
1354{
1355 char input_buf[1];
1356 int rc = user_len;
1357
1358 if (user_len > 0x10000)
1359 user_len = 0x10000;
1360 if (*offset != 0) {
1361 rc = -EPIPE;
1362 goto out;
1363 }
1364 if (copy_from_user(input_buf, user_buf, 1)) {
1365 rc = -EFAULT;
1366 goto out;
1367 }
1368 if (input_buf[0] == '-') {
1369 debug_flush(id, DEBUG_FLUSH_ALL);
1370 goto out;
1371 }
1372 if (isdigit(input_buf[0])) {
1373 int area = ((int) input_buf[0] - (int) '0');
1374
1375 debug_flush(id, area);
1376 goto out;
1377 }
1378
1379 pr_info("Flushing debug data failed because %c is not a valid "
1380 "area\n", input_buf[0]);
1381
1382out:
1383 *offset += user_len;
1384 return rc; /* number of input characters */
1385}
1386
1387/*
1388 * prints debug header in raw format
1389 */
1390static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1391 int area, debug_entry_t *entry, char *out_buf)
1392{
1393 int rc;
1394
1395 rc = sizeof(debug_entry_t);
1396 memcpy(out_buf, entry, sizeof(debug_entry_t));
1397 return rc;
1398}
1399
1400/*
1401 * prints debug data in raw format
1402 */
1403static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1404 char *out_buf, const char *in_buf)
1405{
1406 int rc;
1407
1408 rc = id->buf_size;
1409 memcpy(out_buf, in_buf, id->buf_size);
1410 return rc;
1411}
1412
1413/*
1414 * prints debug data in hex/ascii format
1415 */
1416static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1417 char *out_buf, const char *in_buf)
1418{
1419 int i, rc = 0;
1420
1421 for (i = 0; i < id->buf_size; i++)
1422 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1423 rc += sprintf(out_buf + rc, "| ");
1424 for (i = 0; i < id->buf_size; i++) {
1425 unsigned char c = in_buf[i];
1426
1427 if (isascii(c) && isprint(c))
1428 rc += sprintf(out_buf + rc, "%c", c);
1429 else
1430 rc += sprintf(out_buf + rc, ".");
1431 }
1432 rc += sprintf(out_buf + rc, "\n");
1433 return rc;
1434}
1435
1436/*
1437 * prints header for debug entry
1438 */
1439int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1440 int area, debug_entry_t *entry, char *out_buf)
1441{
1442 unsigned long base, sec, usec;
1443 unsigned long caller;
1444 unsigned int level;
1445 char *except_str;
1446 int rc = 0;
1447
1448 level = entry->id.fields.level;
1449 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1450 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1451 usec = do_div(sec, USEC_PER_SEC);
1452
1453 if (entry->id.fields.exception)
1454 except_str = "*";
1455 else
1456 except_str = "-";
1457 caller = (unsigned long) entry->caller;
1458 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1459 area, sec, usec, level, except_str,
1460 entry->id.fields.cpuid, (void *)caller);
1461 return rc;
1462}
1463EXPORT_SYMBOL(debug_dflt_header_fn);
1464
1465/*
1466 * prints debug data sprintf-formated:
1467 * debug_sprinf_event/exception calls must be used together with this view
1468 */
1469
1470#define DEBUG_SPRINTF_MAX_ARGS 10
1471
1472static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1473 char *out_buf, debug_sprintf_entry_t *curr_event)
1474{
1475 int num_longs, num_used_args = 0, i, rc = 0;
1476 int index[DEBUG_SPRINTF_MAX_ARGS];
1477
1478 /* count of longs fit into one entry */
1479 num_longs = id->buf_size / sizeof(long);
1480
1481 if (num_longs < 1)
1482 goto out; /* bufsize of entry too small */
1483 if (num_longs == 1) {
1484 /* no args, we use only the string */
1485 strcpy(out_buf, curr_event->string);
1486 rc = strlen(curr_event->string);
1487 goto out;
1488 }
1489
1490 /* number of arguments used for sprintf (without the format string) */
1491 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1492
1493 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1494
1495 for (i = 0; i < num_used_args; i++)
1496 index[i] = i;
1497
1498 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1499 curr_event->args[index[1]], curr_event->args[index[2]],
1500 curr_event->args[index[3]], curr_event->args[index[4]],
1501 curr_event->args[index[5]], curr_event->args[index[6]],
1502 curr_event->args[index[7]], curr_event->args[index[8]],
1503 curr_event->args[index[9]]);
1504out:
1505 return rc;
1506}
1507
1508/*
1509 * debug_init:
1510 * - is called exactly once to initialize the debug feature
1511 */
1512static int __init debug_init(void)
1513{
1514 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1515 mutex_lock(&debug_mutex);
1516 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1517 initialized = 1;
1518 mutex_unlock(&debug_mutex);
1519 return 0;
1520}
1521postcore_initcall(debug_init);
1/*
2 * arch/s390/kernel/debug.c
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 <asm/uaccess.h>
24#include <linux/module.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{
56 char *string;
57 /*
58 * This assumes that all args are converted into longs
59 * on L/390 this is the case for all types of parameter
60 * except of floats, and long long (32 bit)
61 *
62 */
63 long args[0];
64} debug_sprintf_entry_t;
65
66
67/* internal function prototyes */
68
69static int debug_init(void);
70static ssize_t debug_output(struct file *file, char __user *user_buf,
71 size_t user_len, loff_t * offset);
72static ssize_t debug_input(struct file *file, const char __user *user_buf,
73 size_t user_len, loff_t * offset);
74static int debug_open(struct inode *inode, struct file *file);
75static int debug_close(struct inode *inode, struct file *file);
76static debug_info_t *debug_info_create(const char *name, int pages_per_area,
77 int nr_areas, int buf_size, umode_t mode);
78static void debug_info_get(debug_info_t *);
79static void debug_info_put(debug_info_t *);
80static int debug_prolog_level_fn(debug_info_t * id,
81 struct debug_view *view, char *out_buf);
82static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
83 struct file *file, const char __user *user_buf,
84 size_t user_buf_size, loff_t * offset);
85static int debug_prolog_pages_fn(debug_info_t * id,
86 struct debug_view *view, char *out_buf);
87static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
88 struct file *file, const char __user *user_buf,
89 size_t user_buf_size, loff_t * offset);
90static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
91 struct file *file, const char __user *user_buf,
92 size_t user_buf_size, loff_t * offset);
93static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
94 char *out_buf, const char *in_buf);
95static int debug_raw_format_fn(debug_info_t * id,
96 struct debug_view *view, char *out_buf,
97 const char *in_buf);
98static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
99 int area, debug_entry_t * entry, char *out_buf);
100
101static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
102 char *out_buf, debug_sprintf_entry_t *curr_event);
103
104/* globals */
105
106struct debug_view debug_raw_view = {
107 "raw",
108 NULL,
109 &debug_raw_header_fn,
110 &debug_raw_format_fn,
111 NULL,
112 NULL
113};
114
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};
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};
159
160/* used by dump analysis tools to determine version of debug feature */
161static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
162
163/* static globals */
164
165static debug_info_t *debug_area_first = NULL;
166static debug_info_t *debug_area_last = NULL;
167static DEFINE_MUTEX(debug_mutex);
168
169static int initialized;
170static int debug_critical;
171
172static const struct file_operations debug_file_ops = {
173 .owner = THIS_MODULE,
174 .read = debug_output,
175 .write = debug_input,
176 .open = debug_open,
177 .release = debug_close,
178 .llseek = no_llseek,
179};
180
181static struct dentry *debug_debugfs_root_entry;
182
183/* functions */
184
185/*
186 * debug_areas_alloc
187 * - Debug areas are implemented as a threedimensonal array:
188 * areas[areanumber][pagenumber][pageoffset]
189 */
190
191static debug_entry_t***
192debug_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 *
198 sizeof(debug_entry_t**),
199 GFP_KERNEL);
200 if (!areas)
201 goto fail_malloc_areas;
202 for (i = 0; i < nr_areas; i++) {
203 areas[i] = kmalloc(pages_per_area *
204 sizeof(debug_entry_t*),GFP_KERNEL);
205 if (!areas[i]) {
206 goto fail_malloc_areas2;
207 }
208 for(j = 0; j < pages_per_area; j++) {
209 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
210 if(!areas[i][j]) {
211 for(j--; j >=0 ; j--) {
212 kfree(areas[i][j]);
213 }
214 kfree(areas[i]);
215 goto fail_malloc_areas2;
216 }
217 }
218 }
219 return areas;
220
221fail_malloc_areas2:
222 for(i--; i >= 0; i--){
223 for(j=0; j < pages_per_area;j++){
224 kfree(areas[i][j]);
225 }
226 kfree(areas[i]);
227 }
228 kfree(areas);
229fail_malloc_areas:
230 return NULL;
231
232}
233
234
235/*
236 * debug_info_alloc
237 * - alloc new debug-info
238 */
239
240static debug_info_t*
241debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
242 int buf_size, int level, int mode)
243{
244 debug_info_t* rc;
245
246 /* alloc everything */
247
248 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
249 if(!rc)
250 goto fail_malloc_rc;
251 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
252 if(!rc->active_entries)
253 goto fail_malloc_active_entries;
254 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
255 if(!rc->active_pages)
256 goto fail_malloc_active_pages;
257 if((mode == ALL_AREAS) && (pages_per_area != 0)){
258 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
259 if(!rc->areas)
260 goto fail_malloc_areas;
261 } else {
262 rc->areas = NULL;
263 }
264
265 /* initialize members */
266
267 spin_lock_init(&rc->lock);
268 rc->pages_per_area = pages_per_area;
269 rc->nr_areas = nr_areas;
270 rc->active_area = 0;
271 rc->level = level;
272 rc->buf_size = buf_size;
273 rc->entry_size = sizeof(debug_entry_t) + buf_size;
274 strlcpy(rc->name, name, sizeof(rc->name));
275 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
276 memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
277 sizeof(struct dentry*));
278 atomic_set(&(rc->ref_count), 0);
279
280 return rc;
281
282fail_malloc_areas:
283 kfree(rc->active_pages);
284fail_malloc_active_pages:
285 kfree(rc->active_entries);
286fail_malloc_active_entries:
287 kfree(rc);
288fail_malloc_rc:
289 return NULL;
290}
291
292/*
293 * debug_areas_free
294 * - free all debug areas
295 */
296
297static void
298debug_areas_free(debug_info_t* db_info)
299{
300 int i,j;
301
302 if(!db_info->areas)
303 return;
304 for (i = 0; i < db_info->nr_areas; i++) {
305 for(j = 0; j < db_info->pages_per_area; j++) {
306 kfree(db_info->areas[i][j]);
307 }
308 kfree(db_info->areas[i]);
309 }
310 kfree(db_info->areas);
311 db_info->areas = NULL;
312}
313
314/*
315 * debug_info_free
316 * - free memory debug-info
317 */
318
319static void
320debug_info_free(debug_info_t* db_info){
321 debug_areas_free(db_info);
322 kfree(db_info->active_entries);
323 kfree(db_info->active_pages);
324 kfree(db_info);
325}
326
327/*
328 * debug_info_create
329 * - create new debug-info
330 */
331
332static debug_info_t*
333debug_info_create(const char *name, int pages_per_area, int nr_areas,
334 int buf_size, umode_t mode)
335{
336 debug_info_t* rc;
337
338 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
339 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
340 if(!rc)
341 goto out;
342
343 rc->mode = mode & ~S_IFMT;
344
345 /* create root directory */
346 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
347 debug_debugfs_root_entry);
348
349 /* append new element to linked list */
350 if (!debug_area_first) {
351 /* first element in list */
352 debug_area_first = rc;
353 rc->prev = NULL;
354 } else {
355 /* append element to end of list */
356 debug_area_last->next = rc;
357 rc->prev = debug_area_last;
358 }
359 debug_area_last = rc;
360 rc->next = NULL;
361
362 debug_info_get(rc);
363out:
364 return rc;
365}
366
367/*
368 * debug_info_copy
369 * - copy debug-info
370 */
371
372static debug_info_t*
373debug_info_copy(debug_info_t* in, int mode)
374{
375 int i,j;
376 debug_info_t* rc;
377 unsigned long flags;
378
379 /* get a consistent copy of the debug areas */
380 do {
381 rc = debug_info_alloc(in->name, in->pages_per_area,
382 in->nr_areas, in->buf_size, in->level, mode);
383 spin_lock_irqsave(&in->lock, flags);
384 if(!rc)
385 goto out;
386 /* has something changed in the meantime ? */
387 if((rc->pages_per_area == in->pages_per_area) &&
388 (rc->nr_areas == in->nr_areas)) {
389 break;
390 }
391 spin_unlock_irqrestore(&in->lock, flags);
392 debug_info_free(rc);
393 } while (1);
394
395 if (mode == NO_AREAS)
396 goto out;
397
398 for(i = 0; i < in->nr_areas; i++){
399 for(j = 0; j < in->pages_per_area; j++) {
400 memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
401 }
402 }
403out:
404 spin_unlock_irqrestore(&in->lock, flags);
405 return rc;
406}
407
408/*
409 * debug_info_get
410 * - increments reference count for debug-info
411 */
412
413static void
414debug_info_get(debug_info_t * db_info)
415{
416 if (db_info)
417 atomic_inc(&db_info->ref_count);
418}
419
420/*
421 * debug_info_put:
422 * - decreases reference count for debug-info and frees it if necessary
423 */
424
425static void
426debug_info_put(debug_info_t *db_info)
427{
428 int i;
429
430 if (!db_info)
431 return;
432 if (atomic_dec_and_test(&db_info->ref_count)) {
433 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
434 if (!db_info->views[i])
435 continue;
436 debugfs_remove(db_info->debugfs_entries[i]);
437 }
438 debugfs_remove(db_info->debugfs_root_entry);
439 if(db_info == debug_area_first)
440 debug_area_first = db_info->next;
441 if(db_info == debug_area_last)
442 debug_area_last = db_info->prev;
443 if(db_info->prev) db_info->prev->next = db_info->next;
444 if(db_info->next) db_info->next->prev = db_info->prev;
445 debug_info_free(db_info);
446 }
447}
448
449/*
450 * debug_format_entry:
451 * - format one debug entry and return size of formated data
452 */
453
454static int
455debug_format_entry(file_private_info_t *p_info)
456{
457 debug_info_t *id_snap = p_info->debug_info_snap;
458 struct debug_view *view = p_info->view;
459 debug_entry_t *act_entry;
460 size_t len = 0;
461 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
462 /* print prolog */
463 if (view->prolog_proc)
464 len += view->prolog_proc(id_snap,view,p_info->temp_buf);
465 goto out;
466 }
467 if (!id_snap->areas) /* this is true, if we have a prolog only view */
468 goto out; /* or if 'pages_per_area' is 0 */
469 act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
470 [p_info->act_page] + p_info->act_entry);
471
472 if (act_entry->id.stck == 0LL)
473 goto out; /* empty entry */
474 if (view->header_proc)
475 len += view->header_proc(id_snap, view, p_info->act_area,
476 act_entry, p_info->temp_buf + len);
477 if (view->format_proc)
478 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
479 DEBUG_DATA(act_entry));
480out:
481 return len;
482}
483
484/*
485 * debug_next_entry:
486 * - goto next entry in p_info
487 */
488
489static inline int
490debug_next_entry(file_private_info_t *p_info)
491{
492 debug_info_t *id;
493
494 id = p_info->debug_info_snap;
495 if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
496 p_info->act_entry = 0;
497 p_info->act_page = 0;
498 goto out;
499 }
500 if(!id->areas)
501 return 1;
502 p_info->act_entry += id->entry_size;
503 /* switch to next page, if we reached the end of the page */
504 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
505 /* next page */
506 p_info->act_entry = 0;
507 p_info->act_page += 1;
508 if((p_info->act_page % id->pages_per_area) == 0) {
509 /* next area */
510 p_info->act_area++;
511 p_info->act_page=0;
512 }
513 if(p_info->act_area >= id->nr_areas)
514 return 1;
515 }
516out:
517 return 0;
518}
519
520/*
521 * debug_output:
522 * - called for user read()
523 * - copies formated debug entries to the user buffer
524 */
525
526static ssize_t
527debug_output(struct file *file, /* file descriptor */
528 char __user *user_buf, /* user buffer */
529 size_t len, /* length of buffer */
530 loff_t *offset) /* offset in the file */
531{
532 size_t count = 0;
533 size_t entry_offset;
534 file_private_info_t *p_info;
535
536 p_info = ((file_private_info_t *) file->private_data);
537 if (*offset != p_info->offset)
538 return -EPIPE;
539 if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
540 return 0;
541 entry_offset = p_info->act_entry_offset;
542 while(count < len){
543 int formatted_line_size;
544 int formatted_line_residue;
545 int user_buf_residue;
546 size_t copy_size;
547
548 formatted_line_size = debug_format_entry(p_info);
549 formatted_line_residue = formatted_line_size - entry_offset;
550 user_buf_residue = len-count;
551 copy_size = min(user_buf_residue, formatted_line_residue);
552 if(copy_size){
553 if (copy_to_user(user_buf + count, p_info->temp_buf
554 + entry_offset, copy_size))
555 return -EFAULT;
556 count += copy_size;
557 entry_offset += copy_size;
558 }
559 if(copy_size == formatted_line_residue){
560 entry_offset = 0;
561 if(debug_next_entry(p_info))
562 goto out;
563 }
564 }
565out:
566 p_info->offset = *offset + count;
567 p_info->act_entry_offset = entry_offset;
568 *offset = p_info->offset;
569 return count;
570}
571
572/*
573 * debug_input:
574 * - called for user write()
575 * - calls input function of view
576 */
577
578static ssize_t
579debug_input(struct file *file, const char __user *user_buf, size_t length,
580 loff_t *offset)
581{
582 int rc = 0;
583 file_private_info_t *p_info;
584
585 mutex_lock(&debug_mutex);
586 p_info = ((file_private_info_t *) file->private_data);
587 if (p_info->view->input_proc)
588 rc = p_info->view->input_proc(p_info->debug_info_org,
589 p_info->view, file, user_buf,
590 length, offset);
591 else
592 rc = -EPERM;
593 mutex_unlock(&debug_mutex);
594 return rc; /* number of input characters */
595}
596
597/*
598 * debug_open:
599 * - called for user open()
600 * - copies formated output to private_data area of the file
601 * handle
602 */
603
604static int
605debug_open(struct inode *inode, struct file *file)
606{
607 int i, rc = 0;
608 file_private_info_t *p_info;
609 debug_info_t *debug_info, *debug_info_snapshot;
610
611 mutex_lock(&debug_mutex);
612 debug_info = file->f_path.dentry->d_inode->i_private;
613 /* find debug view */
614 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
615 if (!debug_info->views[i])
616 continue;
617 else if (debug_info->debugfs_entries[i] ==
618 file->f_path.dentry) {
619 goto found; /* found view ! */
620 }
621 }
622 /* no entry found */
623 rc = -EINVAL;
624 goto out;
625
626found:
627
628 /* Make snapshot of current debug areas to get it consistent. */
629 /* To copy all the areas is only needed, if we have a view which */
630 /* formats the debug areas. */
631
632 if(!debug_info->views[i]->format_proc &&
633 !debug_info->views[i]->header_proc){
634 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
635 } else {
636 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
637 }
638
639 if(!debug_info_snapshot){
640 rc = -ENOMEM;
641 goto out;
642 }
643 p_info = kmalloc(sizeof(file_private_info_t),
644 GFP_KERNEL);
645 if(!p_info){
646 debug_info_free(debug_info_snapshot);
647 rc = -ENOMEM;
648 goto out;
649 }
650 p_info->offset = 0;
651 p_info->debug_info_snap = debug_info_snapshot;
652 p_info->debug_info_org = debug_info;
653 p_info->view = debug_info->views[i];
654 p_info->act_area = 0;
655 p_info->act_page = 0;
656 p_info->act_entry = DEBUG_PROLOG_ENTRY;
657 p_info->act_entry_offset = 0;
658 file->private_data = p_info;
659 debug_info_get(debug_info);
660 nonseekable_open(inode, file);
661out:
662 mutex_unlock(&debug_mutex);
663 return rc;
664}
665
666/*
667 * debug_close:
668 * - called for user close()
669 * - deletes private_data area of the file handle
670 */
671
672static int
673debug_close(struct inode *inode, struct file *file)
674{
675 file_private_info_t *p_info;
676 p_info = (file_private_info_t *) file->private_data;
677 if(p_info->debug_info_snap)
678 debug_info_free(p_info->debug_info_snap);
679 debug_info_put(p_info->debug_info_org);
680 kfree(file->private_data);
681 return 0; /* success */
682}
683
684/*
685 * debug_register_mode:
686 * - Creates and initializes debug area for the caller
687 * The mode parameter allows to specify access rights for the s390dbf files
688 * - Returns handle for debug area
689 */
690
691debug_info_t *debug_register_mode(const char *name, int pages_per_area,
692 int nr_areas, int buf_size, umode_t mode,
693 uid_t uid, gid_t gid)
694{
695 debug_info_t *rc = NULL;
696
697 /* Since debugfs currently does not support uid/gid other than root, */
698 /* we do not allow gid/uid != 0 until we get support for that. */
699 if ((uid != 0) || (gid != 0))
700 pr_warning("Root becomes the owner of all s390dbf files "
701 "in sysfs\n");
702 BUG_ON(!initialized);
703 mutex_lock(&debug_mutex);
704
705 /* create new debug_info */
706
707 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
708 if(!rc)
709 goto out;
710 debug_register_view(rc, &debug_level_view);
711 debug_register_view(rc, &debug_flush_view);
712 debug_register_view(rc, &debug_pages_view);
713out:
714 if (!rc){
715 pr_err("Registering debug feature %s failed\n", name);
716 }
717 mutex_unlock(&debug_mutex);
718 return rc;
719}
720EXPORT_SYMBOL(debug_register_mode);
721
722/*
723 * debug_register:
724 * - creates and initializes debug area for the caller
725 * - returns handle for debug area
726 */
727
728debug_info_t *debug_register(const char *name, int pages_per_area,
729 int nr_areas, int buf_size)
730{
731 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
732 S_IRUSR | S_IWUSR, 0, 0);
733}
734
735/*
736 * debug_unregister:
737 * - give back debug area
738 */
739
740void
741debug_unregister(debug_info_t * id)
742{
743 if (!id)
744 goto out;
745 mutex_lock(&debug_mutex);
746 debug_info_put(id);
747 mutex_unlock(&debug_mutex);
748
749out:
750 return;
751}
752
753/*
754 * debug_set_size:
755 * - set area size (number of pages) and number of areas
756 */
757static int
758debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
759{
760 unsigned long flags;
761 debug_entry_t *** new_areas;
762 int rc=0;
763
764 if(!id || (nr_areas <= 0) || (pages_per_area < 0))
765 return -EINVAL;
766 if(pages_per_area > 0){
767 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
768 if(!new_areas) {
769 pr_info("Allocating memory for %i pages failed\n",
770 pages_per_area);
771 rc = -ENOMEM;
772 goto out;
773 }
774 } else {
775 new_areas = NULL;
776 }
777 spin_lock_irqsave(&id->lock,flags);
778 debug_areas_free(id);
779 id->areas = new_areas;
780 id->nr_areas = nr_areas;
781 id->pages_per_area = pages_per_area;
782 id->active_area = 0;
783 memset(id->active_entries,0,sizeof(int)*id->nr_areas);
784 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
785 spin_unlock_irqrestore(&id->lock,flags);
786 pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
787out:
788 return rc;
789}
790
791/*
792 * debug_set_level:
793 * - set actual debug level
794 */
795
796void
797debug_set_level(debug_info_t* id, int new_level)
798{
799 unsigned long flags;
800 if(!id)
801 return;
802 spin_lock_irqsave(&id->lock,flags);
803 if(new_level == DEBUG_OFF_LEVEL){
804 id->level = DEBUG_OFF_LEVEL;
805 pr_info("%s: switched off\n",id->name);
806 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
807 pr_info("%s: level %i is out of range (%i - %i)\n",
808 id->name, new_level, 0, DEBUG_MAX_LEVEL);
809 } else {
810 id->level = new_level;
811 }
812 spin_unlock_irqrestore(&id->lock,flags);
813}
814
815
816/*
817 * proceed_active_entry:
818 * - set active entry to next in the ring buffer
819 */
820
821static inline void
822proceed_active_entry(debug_info_t * id)
823{
824 if ((id->active_entries[id->active_area] += id->entry_size)
825 > (PAGE_SIZE - id->entry_size)){
826 id->active_entries[id->active_area] = 0;
827 id->active_pages[id->active_area] =
828 (id->active_pages[id->active_area] + 1) %
829 id->pages_per_area;
830 }
831}
832
833/*
834 * proceed_active_area:
835 * - set active area to next in the ring buffer
836 */
837
838static inline void
839proceed_active_area(debug_info_t * id)
840{
841 id->active_area++;
842 id->active_area = id->active_area % id->nr_areas;
843}
844
845/*
846 * get_active_entry:
847 */
848
849static inline debug_entry_t*
850get_active_entry(debug_info_t * id)
851{
852 return (debug_entry_t *) (((char *) id->areas[id->active_area]
853 [id->active_pages[id->active_area]]) +
854 id->active_entries[id->active_area]);
855}
856
857/*
858 * debug_finish_entry:
859 * - set timestamp, caller address, cpu number etc.
860 */
861
862static inline void
863debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
864 int exception)
865{
866 active->id.stck = get_clock();
867 active->id.fields.cpuid = smp_processor_id();
868 active->caller = __builtin_return_address(0);
869 active->id.fields.exception = exception;
870 active->id.fields.level = level;
871 proceed_active_entry(id);
872 if(exception)
873 proceed_active_area(id);
874}
875
876static int debug_stoppable=1;
877static int debug_active=1;
878
879#define CTL_S390DBF_STOPPABLE 5678
880#define CTL_S390DBF_ACTIVE 5679
881
882/*
883 * proc handler for the running debug_active sysctl
884 * always allow read, allow write only if debug_stoppable is set or
885 * if debug_active is already off
886 */
887static int
888s390dbf_procactive(ctl_table *table, int write,
889 void __user *buffer, size_t *lenp, loff_t *ppos)
890{
891 if (!write || debug_stoppable || !debug_active)
892 return proc_dointvec(table, write, buffer, lenp, ppos);
893 else
894 return 0;
895}
896
897
898static struct ctl_table s390dbf_table[] = {
899 {
900 .procname = "debug_stoppable",
901 .data = &debug_stoppable,
902 .maxlen = sizeof(int),
903 .mode = S_IRUGO | S_IWUSR,
904 .proc_handler = proc_dointvec,
905 },
906 {
907 .procname = "debug_active",
908 .data = &debug_active,
909 .maxlen = sizeof(int),
910 .mode = S_IRUGO | S_IWUSR,
911 .proc_handler = s390dbf_procactive,
912 },
913 { }
914};
915
916static struct ctl_table s390dbf_dir_table[] = {
917 {
918 .procname = "s390dbf",
919 .maxlen = 0,
920 .mode = S_IRUGO | S_IXUGO,
921 .child = s390dbf_table,
922 },
923 { }
924};
925
926static struct ctl_table_header *s390dbf_sysctl_header;
927
928void
929debug_stop_all(void)
930{
931 if (debug_stoppable)
932 debug_active = 0;
933}
934
935
936void debug_set_critical(void)
937{
938 debug_critical = 1;
939}
940
941/*
942 * debug_event_common:
943 * - write debug entry with given size
944 */
945
946debug_entry_t*
947debug_event_common(debug_info_t * id, int level, const void *buf, int len)
948{
949 unsigned long flags;
950 debug_entry_t *active;
951
952 if (!debug_active || !id->areas)
953 return NULL;
954 if (debug_critical) {
955 if (!spin_trylock_irqsave(&id->lock, flags))
956 return NULL;
957 } else
958 spin_lock_irqsave(&id->lock, flags);
959 active = get_active_entry(id);
960 memset(DEBUG_DATA(active), 0, id->buf_size);
961 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
962 debug_finish_entry(id, active, level, 0);
963 spin_unlock_irqrestore(&id->lock, flags);
964
965 return active;
966}
967
968/*
969 * debug_exception_common:
970 * - write debug entry with given size and switch to next debug area
971 */
972
973debug_entry_t
974*debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
975{
976 unsigned long flags;
977 debug_entry_t *active;
978
979 if (!debug_active || !id->areas)
980 return NULL;
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 active = get_active_entry(id);
987 memset(DEBUG_DATA(active), 0, id->buf_size);
988 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
989 debug_finish_entry(id, active, level, 1);
990 spin_unlock_irqrestore(&id->lock, flags);
991
992 return active;
993}
994
995/*
996 * counts arguments in format string for sprintf view
997 */
998
999static inline int
1000debug_count_numargs(char *string)
1001{
1002 int numargs=0;
1003
1004 while(*string) {
1005 if(*string++=='%')
1006 numargs++;
1007 }
1008 return(numargs);
1009}
1010
1011/*
1012 * debug_sprintf_event:
1013 */
1014
1015debug_entry_t*
1016debug_sprintf_event(debug_info_t* id, int level,char *string,...)
1017{
1018 va_list ap;
1019 int numargs,idx;
1020 unsigned long flags;
1021 debug_sprintf_entry_t *curr_event;
1022 debug_entry_t *active;
1023
1024 if((!id) || (level > id->level))
1025 return NULL;
1026 if (!debug_active || !id->areas)
1027 return NULL;
1028 numargs=debug_count_numargs(string);
1029
1030 if (debug_critical) {
1031 if (!spin_trylock_irqsave(&id->lock, flags))
1032 return NULL;
1033 } else
1034 spin_lock_irqsave(&id->lock, flags);
1035 active = get_active_entry(id);
1036 curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1037 va_start(ap,string);
1038 curr_event->string=string;
1039 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1040 curr_event->args[idx]=va_arg(ap,long);
1041 va_end(ap);
1042 debug_finish_entry(id, active, level, 0);
1043 spin_unlock_irqrestore(&id->lock, flags);
1044
1045 return active;
1046}
1047
1048/*
1049 * debug_sprintf_exception:
1050 */
1051
1052debug_entry_t*
1053debug_sprintf_exception(debug_info_t* id, int level,char *string,...)
1054{
1055 va_list ap;
1056 int numargs,idx;
1057 unsigned long flags;
1058 debug_sprintf_entry_t *curr_event;
1059 debug_entry_t *active;
1060
1061 if((!id) || (level > id->level))
1062 return NULL;
1063 if (!debug_active || !id->areas)
1064 return NULL;
1065
1066 numargs=debug_count_numargs(string);
1067
1068 if (debug_critical) {
1069 if (!spin_trylock_irqsave(&id->lock, flags))
1070 return NULL;
1071 } else
1072 spin_lock_irqsave(&id->lock, flags);
1073 active = get_active_entry(id);
1074 curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1075 va_start(ap,string);
1076 curr_event->string=string;
1077 for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1078 curr_event->args[idx]=va_arg(ap,long);
1079 va_end(ap);
1080 debug_finish_entry(id, active, level, 1);
1081 spin_unlock_irqrestore(&id->lock, flags);
1082
1083 return active;
1084}
1085
1086/*
1087 * debug_init:
1088 * - is called exactly once to initialize the debug feature
1089 */
1090
1091static int
1092__init debug_init(void)
1093{
1094 int rc = 0;
1095
1096 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1097 mutex_lock(&debug_mutex);
1098 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT,NULL);
1099 initialized = 1;
1100 mutex_unlock(&debug_mutex);
1101
1102 return rc;
1103}
1104
1105/*
1106 * debug_register_view:
1107 */
1108
1109int
1110debug_register_view(debug_info_t * id, struct debug_view *view)
1111{
1112 int rc = 0;
1113 int i;
1114 unsigned long flags;
1115 umode_t mode;
1116 struct dentry *pde;
1117
1118 if (!id)
1119 goto out;
1120 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1121 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1122 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1123 if (!view->input_proc)
1124 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1125 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1126 id , &debug_file_ops);
1127 if (!pde){
1128 pr_err("Registering view %s/%s failed due to out of "
1129 "memory\n", id->name,view->name);
1130 rc = -1;
1131 goto out;
1132 }
1133 spin_lock_irqsave(&id->lock, flags);
1134 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1135 if (!id->views[i])
1136 break;
1137 }
1138 if (i == DEBUG_MAX_VIEWS) {
1139 pr_err("Registering view %s/%s would exceed the maximum "
1140 "number of views %i\n", id->name, view->name, i);
1141 debugfs_remove(pde);
1142 rc = -1;
1143 } else {
1144 id->views[i] = view;
1145 id->debugfs_entries[i] = pde;
1146 }
1147 spin_unlock_irqrestore(&id->lock, flags);
1148out:
1149 return rc;
1150}
1151
1152/*
1153 * debug_unregister_view:
1154 */
1155
1156int
1157debug_unregister_view(debug_info_t * id, struct debug_view *view)
1158{
1159 int rc = 0;
1160 int i;
1161 unsigned long flags;
1162
1163 if (!id)
1164 goto out;
1165 spin_lock_irqsave(&id->lock, flags);
1166 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1167 if (id->views[i] == view)
1168 break;
1169 }
1170 if (i == DEBUG_MAX_VIEWS)
1171 rc = -1;
1172 else {
1173 debugfs_remove(id->debugfs_entries[i]);
1174 id->views[i] = NULL;
1175 }
1176 spin_unlock_irqrestore(&id->lock, flags);
1177out:
1178 return rc;
1179}
1180
1181static inline char *
1182debug_get_user_string(const char __user *user_buf, size_t user_len)
1183{
1184 char* buffer;
1185
1186 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1187 if (!buffer)
1188 return ERR_PTR(-ENOMEM);
1189 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1190 kfree(buffer);
1191 return ERR_PTR(-EFAULT);
1192 }
1193 /* got the string, now strip linefeed. */
1194 if (buffer[user_len - 1] == '\n')
1195 buffer[user_len - 1] = 0;
1196 else
1197 buffer[user_len] = 0;
1198 return buffer;
1199}
1200
1201static inline int
1202debug_get_uint(char *buf)
1203{
1204 int rc;
1205
1206 buf = skip_spaces(buf);
1207 rc = simple_strtoul(buf, &buf, 10);
1208 if(*buf){
1209 rc = -EINVAL;
1210 }
1211 return rc;
1212}
1213
1214/*
1215 * functions for debug-views
1216 ***********************************
1217*/
1218
1219/*
1220 * prints out actual debug level
1221 */
1222
1223static int
1224debug_prolog_pages_fn(debug_info_t * id,
1225 struct debug_view *view, char *out_buf)
1226{
1227 return sprintf(out_buf, "%i\n", id->pages_per_area);
1228}
1229
1230/*
1231 * reads new size (number of pages per debug area)
1232 */
1233
1234static int
1235debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1236 struct file *file, const char __user *user_buf,
1237 size_t user_len, loff_t * offset)
1238{
1239 char *str;
1240 int rc,new_pages;
1241
1242 if (user_len > 0x10000)
1243 user_len = 0x10000;
1244 if (*offset != 0){
1245 rc = -EPIPE;
1246 goto out;
1247 }
1248 str = debug_get_user_string(user_buf,user_len);
1249 if(IS_ERR(str)){
1250 rc = PTR_ERR(str);
1251 goto out;
1252 }
1253 new_pages = debug_get_uint(str);
1254 if(new_pages < 0){
1255 rc = -EINVAL;
1256 goto free_str;
1257 }
1258 rc = debug_set_size(id,id->nr_areas, new_pages);
1259 if(rc != 0){
1260 rc = -EINVAL;
1261 goto free_str;
1262 }
1263 rc = user_len;
1264free_str:
1265 kfree(str);
1266out:
1267 *offset += user_len;
1268 return rc; /* number of input characters */
1269}
1270
1271/*
1272 * prints out actual debug level
1273 */
1274
1275static int
1276debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1277{
1278 int rc = 0;
1279
1280 if(id->level == DEBUG_OFF_LEVEL) {
1281 rc = sprintf(out_buf,"-\n");
1282 }
1283 else {
1284 rc = sprintf(out_buf, "%i\n", id->level);
1285 }
1286 return rc;
1287}
1288
1289/*
1290 * reads new debug level
1291 */
1292
1293static int
1294debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1295 struct file *file, const char __user *user_buf,
1296 size_t user_len, loff_t * offset)
1297{
1298 char *str;
1299 int rc,new_level;
1300
1301 if (user_len > 0x10000)
1302 user_len = 0x10000;
1303 if (*offset != 0){
1304 rc = -EPIPE;
1305 goto out;
1306 }
1307 str = debug_get_user_string(user_buf,user_len);
1308 if(IS_ERR(str)){
1309 rc = PTR_ERR(str);
1310 goto out;
1311 }
1312 if(str[0] == '-'){
1313 debug_set_level(id, DEBUG_OFF_LEVEL);
1314 rc = user_len;
1315 goto free_str;
1316 } else {
1317 new_level = debug_get_uint(str);
1318 }
1319 if(new_level < 0) {
1320 pr_warning("%s is not a valid level for a debug "
1321 "feature\n", str);
1322 rc = -EINVAL;
1323 } else {
1324 debug_set_level(id, new_level);
1325 rc = user_len;
1326 }
1327free_str:
1328 kfree(str);
1329out:
1330 *offset += user_len;
1331 return rc; /* number of input characters */
1332}
1333
1334
1335/*
1336 * flushes debug areas
1337 */
1338
1339static void debug_flush(debug_info_t* id, int area)
1340{
1341 unsigned long flags;
1342 int i,j;
1343
1344 if(!id || !id->areas)
1345 return;
1346 spin_lock_irqsave(&id->lock,flags);
1347 if(area == DEBUG_FLUSH_ALL){
1348 id->active_area = 0;
1349 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1350 for (i = 0; i < id->nr_areas; i++) {
1351 id->active_pages[i] = 0;
1352 for(j = 0; j < id->pages_per_area; j++) {
1353 memset(id->areas[i][j], 0, PAGE_SIZE);
1354 }
1355 }
1356 } else if(area >= 0 && area < id->nr_areas) {
1357 id->active_entries[area] = 0;
1358 id->active_pages[area] = 0;
1359 for(i = 0; i < id->pages_per_area; i++) {
1360 memset(id->areas[area][i],0,PAGE_SIZE);
1361 }
1362 }
1363 spin_unlock_irqrestore(&id->lock,flags);
1364}
1365
1366/*
1367 * view function: flushes debug areas
1368 */
1369
1370static int
1371debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1372 struct file *file, const char __user *user_buf,
1373 size_t user_len, loff_t * offset)
1374{
1375 char input_buf[1];
1376 int rc = user_len;
1377
1378 if (user_len > 0x10000)
1379 user_len = 0x10000;
1380 if (*offset != 0){
1381 rc = -EPIPE;
1382 goto out;
1383 }
1384 if (copy_from_user(input_buf, user_buf, 1)){
1385 rc = -EFAULT;
1386 goto out;
1387 }
1388 if(input_buf[0] == '-') {
1389 debug_flush(id, DEBUG_FLUSH_ALL);
1390 goto out;
1391 }
1392 if (isdigit(input_buf[0])) {
1393 int area = ((int) input_buf[0] - (int) '0');
1394 debug_flush(id, area);
1395 goto out;
1396 }
1397
1398 pr_info("Flushing debug data failed because %c is not a valid "
1399 "area\n", input_buf[0]);
1400
1401out:
1402 *offset += user_len;
1403 return rc; /* number of input characters */
1404}
1405
1406/*
1407 * prints debug header in raw format
1408 */
1409
1410static int
1411debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1412 int area, debug_entry_t * entry, char *out_buf)
1413{
1414 int rc;
1415
1416 rc = sizeof(debug_entry_t);
1417 memcpy(out_buf,entry,sizeof(debug_entry_t));
1418 return rc;
1419}
1420
1421/*
1422 * prints debug data in raw format
1423 */
1424
1425static int
1426debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1427 char *out_buf, const char *in_buf)
1428{
1429 int rc;
1430
1431 rc = id->buf_size;
1432 memcpy(out_buf, in_buf, id->buf_size);
1433 return rc;
1434}
1435
1436/*
1437 * prints debug data in hex/ascii format
1438 */
1439
1440static int
1441debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1442 char *out_buf, const char *in_buf)
1443{
1444 int i, rc = 0;
1445
1446 for (i = 0; i < id->buf_size; i++) {
1447 rc += sprintf(out_buf + rc, "%02x ",
1448 ((unsigned char *) in_buf)[i]);
1449 }
1450 rc += sprintf(out_buf + rc, "| ");
1451 for (i = 0; i < id->buf_size; i++) {
1452 unsigned char c = in_buf[i];
1453 if (isascii(c) && isprint(c))
1454 rc += sprintf(out_buf + rc, "%c", c);
1455 else
1456 rc += sprintf(out_buf + rc, ".");
1457 }
1458 rc += sprintf(out_buf + rc, "\n");
1459 return rc;
1460}
1461
1462/*
1463 * prints header for debug entry
1464 */
1465
1466int
1467debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1468 int area, debug_entry_t * entry, char *out_buf)
1469{
1470 struct timespec time_spec;
1471 char *except_str;
1472 unsigned long caller;
1473 int rc = 0;
1474 unsigned int level;
1475
1476 level = entry->id.fields.level;
1477 stck_to_timespec(entry->id.stck, &time_spec);
1478
1479 if (entry->id.fields.exception)
1480 except_str = "*";
1481 else
1482 except_str = "-";
1483 caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1484 rc += sprintf(out_buf, "%02i %011lu:%06lu %1u %1s %02i %p ",
1485 area, time_spec.tv_sec, time_spec.tv_nsec / 1000, level,
1486 except_str, entry->id.fields.cpuid, (void *) caller);
1487 return rc;
1488}
1489
1490/*
1491 * prints debug data sprintf-formated:
1492 * debug_sprinf_event/exception calls must be used together with this view
1493 */
1494
1495#define DEBUG_SPRINTF_MAX_ARGS 10
1496
1497static int
1498debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1499 char *out_buf, debug_sprintf_entry_t *curr_event)
1500{
1501 int num_longs, num_used_args = 0,i, rc = 0;
1502 int index[DEBUG_SPRINTF_MAX_ARGS];
1503
1504 /* count of longs fit into one entry */
1505 num_longs = id->buf_size / sizeof(long);
1506
1507 if(num_longs < 1)
1508 goto out; /* bufsize of entry too small */
1509 if(num_longs == 1) {
1510 /* no args, we use only the string */
1511 strcpy(out_buf, curr_event->string);
1512 rc = strlen(curr_event->string);
1513 goto out;
1514 }
1515
1516 /* number of arguments used for sprintf (without the format string) */
1517 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1518
1519 memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1520
1521 for(i = 0; i < num_used_args; i++)
1522 index[i] = i;
1523
1524 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1525 curr_event->args[index[1]], curr_event->args[index[2]],
1526 curr_event->args[index[3]], curr_event->args[index[4]],
1527 curr_event->args[index[5]], curr_event->args[index[6]],
1528 curr_event->args[index[7]], curr_event->args[index[8]],
1529 curr_event->args[index[9]]);
1530
1531out:
1532
1533 return rc;
1534}
1535
1536/*
1537 * clean up module
1538 */
1539static void __exit debug_exit(void)
1540{
1541 debugfs_remove(debug_debugfs_root_entry);
1542 unregister_sysctl_table(s390dbf_sysctl_header);
1543 return;
1544}
1545
1546/*
1547 * module definitions
1548 */
1549postcore_initcall(debug_init);
1550module_exit(debug_exit);
1551MODULE_LICENSE("GPL");
1552
1553EXPORT_SYMBOL(debug_register);
1554EXPORT_SYMBOL(debug_unregister);
1555EXPORT_SYMBOL(debug_set_level);
1556EXPORT_SYMBOL(debug_stop_all);
1557EXPORT_SYMBOL(debug_register_view);
1558EXPORT_SYMBOL(debug_unregister_view);
1559EXPORT_SYMBOL(debug_event_common);
1560EXPORT_SYMBOL(debug_exception_common);
1561EXPORT_SYMBOL(debug_hex_ascii_view);
1562EXPORT_SYMBOL(debug_raw_view);
1563EXPORT_SYMBOL(debug_dflt_header_fn);
1564EXPORT_SYMBOL(debug_sprintf_view);
1565EXPORT_SYMBOL(debug_sprintf_exception);
1566EXPORT_SYMBOL(debug_sprintf_event);