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1 /*
2  *   S/390 debug facility
3  *
4  *    Copyright IBM Corp. 1999, 2012
5  *
6  *    Author(s): Michael Holzheu (holzheu@de.ibm.com),
7  *               Holger Smolinski (Holger.Smolinski@de.ibm.com)
8  *
9  *    Bugreports to: <Linux390@de.ibm.com>
10  */
11 
12 #define KMSG_COMPONENT "s390dbf"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 
15 #include <linux/stddef.h>
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/ctype.h>
20 #include <linux/string.h>
21 #include <linux/sysctl.h>
22 #include <asm/uaccess.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/fs.h>
26 #include <linux/debugfs.h>
27 
28 #include <asm/debug.h>
29 
30 #define DEBUG_PROLOG_ENTRY -1
31 
32 #define ALL_AREAS 0 /* copy all debug areas */
33 #define NO_AREAS  1 /* copy no debug areas */
34 
35 /* typedefs */
36 
37 typedef struct file_private_info {
38 	loff_t offset;			/* offset of last read in file */
39 	int    act_area;                /* number of last formated area */
40 	int    act_page;                /* act page in given area */
41 	int    act_entry;               /* last formated entry (offset */
42                                         /* relative to beginning of last */
43                                         /* formated page) */
44 	size_t act_entry_offset;        /* up to this offset we copied */
45 					/* in last read the last formated */
46 					/* entry to userland */
47 	char   temp_buf[2048];		/* buffer for output */
48 	debug_info_t *debug_info_org;   /* original debug information */
49 	debug_info_t *debug_info_snap;	/* snapshot of debug information */
50 	struct debug_view *view;	/* used view of debug info */
51 } file_private_info_t;
52 
53 typedef struct
54 {
55 	char *string;
56 	/*
57 	 * This assumes that all args are converted into longs
58 	 * on L/390 this is the case for all types of parameter
59 	 * except of floats, and long long (32 bit)
60 	 *
61 	 */
62 	long args[0];
63 } debug_sprintf_entry_t;
64 
65 
66 /* internal function prototyes */
67 
68 static int debug_init(void);
69 static ssize_t debug_output(struct file *file, char __user *user_buf,
70 			size_t user_len, loff_t * offset);
71 static ssize_t debug_input(struct file *file, const char __user *user_buf,
72 			size_t user_len, loff_t * offset);
73 static int debug_open(struct inode *inode, struct file *file);
74 static int debug_close(struct inode *inode, struct file *file);
75 static debug_info_t *debug_info_create(const char *name, int pages_per_area,
76 			int nr_areas, int buf_size, umode_t mode);
77 static void debug_info_get(debug_info_t *);
78 static void debug_info_put(debug_info_t *);
79 static int debug_prolog_level_fn(debug_info_t * id,
80 			struct debug_view *view, char *out_buf);
81 static int debug_input_level_fn(debug_info_t * id, struct debug_view *view,
82 			struct file *file, const char __user *user_buf,
83 			size_t user_buf_size, loff_t * offset);
84 static int debug_prolog_pages_fn(debug_info_t * id,
85 			struct debug_view *view, char *out_buf);
86 static int debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
87 			struct file *file, const char __user *user_buf,
88 			size_t user_buf_size, loff_t * offset);
89 static int debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
90 			struct file *file, const char __user *user_buf,
91 			size_t user_buf_size, loff_t * offset);
92 static int debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
93 			char *out_buf, const char *in_buf);
94 static int debug_raw_format_fn(debug_info_t * id,
95 			struct debug_view *view, char *out_buf,
96 			const char *in_buf);
97 static int debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
98 			int area, debug_entry_t * entry, char *out_buf);
99 
100 static int debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
101 			char *out_buf, debug_sprintf_entry_t *curr_event);
102 
103 /* globals */
104 
105 struct debug_view debug_raw_view = {
106 	"raw",
107 	NULL,
108 	&debug_raw_header_fn,
109 	&debug_raw_format_fn,
110 	NULL,
111 	NULL
112 };
113 EXPORT_SYMBOL(debug_raw_view);
114 
115 struct debug_view debug_hex_ascii_view = {
116 	"hex_ascii",
117 	NULL,
118 	&debug_dflt_header_fn,
119 	&debug_hex_ascii_format_fn,
120 	NULL,
121 	NULL
122 };
123 EXPORT_SYMBOL(debug_hex_ascii_view);
124 
125 static struct debug_view debug_level_view = {
126 	"level",
127 	&debug_prolog_level_fn,
128 	NULL,
129 	NULL,
130 	&debug_input_level_fn,
131 	NULL
132 };
133 
134 static struct debug_view debug_pages_view = {
135 	"pages",
136 	&debug_prolog_pages_fn,
137 	NULL,
138 	NULL,
139 	&debug_input_pages_fn,
140 	NULL
141 };
142 
143 static struct debug_view debug_flush_view = {
144         "flush",
145         NULL,
146         NULL,
147         NULL,
148         &debug_input_flush_fn,
149         NULL
150 };
151 
152 struct debug_view debug_sprintf_view = {
153 	"sprintf",
154 	NULL,
155 	&debug_dflt_header_fn,
156 	(debug_format_proc_t*)&debug_sprintf_format_fn,
157 	NULL,
158 	NULL
159 };
160 EXPORT_SYMBOL(debug_sprintf_view);
161 
162 /* used by dump analysis tools to determine version of debug feature */
163 static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
164 
165 /* static globals */
166 
167 static debug_info_t *debug_area_first = NULL;
168 static debug_info_t *debug_area_last = NULL;
169 static DEFINE_MUTEX(debug_mutex);
170 
171 static int initialized;
172 static int debug_critical;
173 
174 static const struct file_operations debug_file_ops = {
175 	.owner   = THIS_MODULE,
176 	.read    = debug_output,
177 	.write   = debug_input,
178 	.open    = debug_open,
179 	.release = debug_close,
180 	.llseek  = no_llseek,
181 };
182 
183 static struct dentry *debug_debugfs_root_entry;
184 
185 /* functions */
186 
187 /*
188  * debug_areas_alloc
189  * - Debug areas are implemented as a threedimensonal array:
190  *   areas[areanumber][pagenumber][pageoffset]
191  */
192 
193 static debug_entry_t***
debug_areas_alloc(int pages_per_area,int nr_areas)194 debug_areas_alloc(int pages_per_area, int nr_areas)
195 {
196 	debug_entry_t*** areas;
197 	int i,j;
198 
199 	areas = kmalloc(nr_areas *
200 					sizeof(debug_entry_t**),
201 					GFP_KERNEL);
202 	if (!areas)
203 		goto fail_malloc_areas;
204 	for (i = 0; i < nr_areas; i++) {
205 		areas[i] = kmalloc(pages_per_area *
206 				sizeof(debug_entry_t*),GFP_KERNEL);
207 		if (!areas[i]) {
208 			goto fail_malloc_areas2;
209 		}
210 		for(j = 0; j < pages_per_area; j++) {
211 			areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
212 			if(!areas[i][j]) {
213 				for(j--; j >=0 ; j--) {
214 					kfree(areas[i][j]);
215 				}
216 				kfree(areas[i]);
217 				goto fail_malloc_areas2;
218 			}
219 		}
220 	}
221 	return areas;
222 
223 fail_malloc_areas2:
224 	for(i--; i >= 0; i--){
225 		for(j=0; j < pages_per_area;j++){
226 			kfree(areas[i][j]);
227 		}
228 		kfree(areas[i]);
229 	}
230 	kfree(areas);
231 fail_malloc_areas:
232 	return NULL;
233 
234 }
235 
236 
237 /*
238  * debug_info_alloc
239  * - alloc new debug-info
240  */
241 
242 static debug_info_t*
debug_info_alloc(const char * name,int pages_per_area,int nr_areas,int buf_size,int level,int mode)243 debug_info_alloc(const char *name, int pages_per_area, int nr_areas,
244 		 int buf_size, int level, int mode)
245 {
246 	debug_info_t* rc;
247 
248 	/* alloc everything */
249 
250 	rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
251 	if(!rc)
252 		goto fail_malloc_rc;
253 	rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
254 	if(!rc->active_entries)
255 		goto fail_malloc_active_entries;
256 	rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
257 	if(!rc->active_pages)
258 		goto fail_malloc_active_pages;
259 	if((mode == ALL_AREAS) && (pages_per_area != 0)){
260 		rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
261 		if(!rc->areas)
262 			goto fail_malloc_areas;
263 	} else {
264 		rc->areas = NULL;
265 	}
266 
267 	/* initialize members */
268 
269 	spin_lock_init(&rc->lock);
270 	rc->pages_per_area = pages_per_area;
271 	rc->nr_areas       = nr_areas;
272 	rc->active_area    = 0;
273 	rc->level          = level;
274 	rc->buf_size       = buf_size;
275 	rc->entry_size     = sizeof(debug_entry_t) + buf_size;
276 	strlcpy(rc->name, name, sizeof(rc->name));
277 	memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
278 	memset(rc->debugfs_entries, 0 ,DEBUG_MAX_VIEWS *
279 		sizeof(struct dentry*));
280 	atomic_set(&(rc->ref_count), 0);
281 
282 	return rc;
283 
284 fail_malloc_areas:
285 	kfree(rc->active_pages);
286 fail_malloc_active_pages:
287 	kfree(rc->active_entries);
288 fail_malloc_active_entries:
289 	kfree(rc);
290 fail_malloc_rc:
291 	return NULL;
292 }
293 
294 /*
295  * debug_areas_free
296  * - free all debug areas
297  */
298 
299 static void
debug_areas_free(debug_info_t * db_info)300 debug_areas_free(debug_info_t* db_info)
301 {
302 	int i,j;
303 
304 	if(!db_info->areas)
305 		return;
306 	for (i = 0; i < db_info->nr_areas; i++) {
307 		for(j = 0; j < db_info->pages_per_area; j++) {
308 			kfree(db_info->areas[i][j]);
309 		}
310 		kfree(db_info->areas[i]);
311 	}
312 	kfree(db_info->areas);
313 	db_info->areas = NULL;
314 }
315 
316 /*
317  * debug_info_free
318  * - free memory debug-info
319  */
320 
321 static void
debug_info_free(debug_info_t * db_info)322 debug_info_free(debug_info_t* db_info){
323 	debug_areas_free(db_info);
324 	kfree(db_info->active_entries);
325 	kfree(db_info->active_pages);
326 	kfree(db_info);
327 }
328 
329 /*
330  * debug_info_create
331  * - create new debug-info
332  */
333 
334 static debug_info_t*
debug_info_create(const char * name,int pages_per_area,int nr_areas,int buf_size,umode_t mode)335 debug_info_create(const char *name, int pages_per_area, int nr_areas,
336 		  int buf_size, umode_t mode)
337 {
338 	debug_info_t* rc;
339 
340         rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
341 				DEBUG_DEFAULT_LEVEL, ALL_AREAS);
342         if(!rc)
343 		goto out;
344 
345 	rc->mode = mode & ~S_IFMT;
346 
347 	/* create root directory */
348         rc->debugfs_root_entry = debugfs_create_dir(rc->name,
349 					debug_debugfs_root_entry);
350 
351 	/* append new element to linked list */
352         if (!debug_area_first) {
353                 /* first element in list */
354                 debug_area_first = rc;
355                 rc->prev = NULL;
356         } else {
357                 /* append element to end of list */
358                 debug_area_last->next = rc;
359                 rc->prev = debug_area_last;
360         }
361         debug_area_last = rc;
362         rc->next = NULL;
363 
364 	debug_info_get(rc);
365 out:
366 	return rc;
367 }
368 
369 /*
370  * debug_info_copy
371  * - copy debug-info
372  */
373 
374 static debug_info_t*
debug_info_copy(debug_info_t * in,int mode)375 debug_info_copy(debug_info_t* in, int mode)
376 {
377         int i,j;
378         debug_info_t* rc;
379         unsigned long flags;
380 
381 	/* get a consistent copy of the debug areas */
382 	do {
383 		rc = debug_info_alloc(in->name, in->pages_per_area,
384 			in->nr_areas, in->buf_size, in->level, mode);
385 		spin_lock_irqsave(&in->lock, flags);
386 		if(!rc)
387 			goto out;
388 		/* has something changed in the meantime ? */
389 		if((rc->pages_per_area == in->pages_per_area) &&
390 		   (rc->nr_areas == in->nr_areas)) {
391 			break;
392 		}
393 		spin_unlock_irqrestore(&in->lock, flags);
394 		debug_info_free(rc);
395 	} while (1);
396 
397 	if (mode == NO_AREAS)
398                 goto out;
399 
400         for(i = 0; i < in->nr_areas; i++){
401 		for(j = 0; j < in->pages_per_area; j++) {
402 			memcpy(rc->areas[i][j], in->areas[i][j],PAGE_SIZE);
403 		}
404         }
405 out:
406         spin_unlock_irqrestore(&in->lock, flags);
407         return rc;
408 }
409 
410 /*
411  * debug_info_get
412  * - increments reference count for debug-info
413  */
414 
415 static void
debug_info_get(debug_info_t * db_info)416 debug_info_get(debug_info_t * db_info)
417 {
418 	if (db_info)
419 		atomic_inc(&db_info->ref_count);
420 }
421 
422 /*
423  * debug_info_put:
424  * - decreases reference count for debug-info and frees it if necessary
425  */
426 
427 static void
debug_info_put(debug_info_t * db_info)428 debug_info_put(debug_info_t *db_info)
429 {
430 	int i;
431 
432 	if (!db_info)
433 		return;
434 	if (atomic_dec_and_test(&db_info->ref_count)) {
435 		for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
436 			if (!db_info->views[i])
437 				continue;
438 			debugfs_remove(db_info->debugfs_entries[i]);
439 		}
440 		debugfs_remove(db_info->debugfs_root_entry);
441 		if(db_info == debug_area_first)
442 			debug_area_first = db_info->next;
443 		if(db_info == debug_area_last)
444 			debug_area_last = db_info->prev;
445 		if(db_info->prev) db_info->prev->next = db_info->next;
446 		if(db_info->next) db_info->next->prev = db_info->prev;
447 		debug_info_free(db_info);
448 	}
449 }
450 
451 /*
452  * debug_format_entry:
453  * - format one debug entry and return size of formated data
454  */
455 
456 static int
debug_format_entry(file_private_info_t * p_info)457 debug_format_entry(file_private_info_t *p_info)
458 {
459 	debug_info_t *id_snap   = p_info->debug_info_snap;
460 	struct debug_view *view = p_info->view;
461 	debug_entry_t *act_entry;
462 	size_t len = 0;
463 	if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
464 		/* print prolog */
465         	if (view->prolog_proc)
466                 	len += view->prolog_proc(id_snap,view,p_info->temp_buf);
467 		goto out;
468 	}
469 	if (!id_snap->areas) /* this is true, if we have a prolog only view */
470 		goto out;    /* or if 'pages_per_area' is 0 */
471 	act_entry = (debug_entry_t *) ((char*)id_snap->areas[p_info->act_area]
472 				[p_info->act_page] + p_info->act_entry);
473 
474 	if (act_entry->id.stck == 0LL)
475 			goto out;  /* empty entry */
476 	if (view->header_proc)
477 		len += view->header_proc(id_snap, view, p_info->act_area,
478 					act_entry, p_info->temp_buf + len);
479 	if (view->format_proc)
480 		len += view->format_proc(id_snap, view, p_info->temp_buf + len,
481 						DEBUG_DATA(act_entry));
482 out:
483         return len;
484 }
485 
486 /*
487  * debug_next_entry:
488  * - goto next entry in p_info
489  */
490 
491 static inline int
debug_next_entry(file_private_info_t * p_info)492 debug_next_entry(file_private_info_t *p_info)
493 {
494 	debug_info_t *id;
495 
496 	id = p_info->debug_info_snap;
497 	if(p_info->act_entry == DEBUG_PROLOG_ENTRY){
498 		p_info->act_entry = 0;
499 		p_info->act_page  = 0;
500 		goto out;
501 	}
502 	if(!id->areas)
503 		return 1;
504 	p_info->act_entry += id->entry_size;
505 	/* switch to next page, if we reached the end of the page  */
506 	if (p_info->act_entry > (PAGE_SIZE - id->entry_size)){
507 		/* next page */
508 		p_info->act_entry = 0;
509 		p_info->act_page += 1;
510 		if((p_info->act_page % id->pages_per_area) == 0) {
511 			/* next area */
512         		p_info->act_area++;
513 			p_info->act_page=0;
514 		}
515         	if(p_info->act_area >= id->nr_areas)
516 			return 1;
517 	}
518 out:
519 	return 0;
520 }
521 
522 /*
523  * debug_output:
524  * - called for user read()
525  * - copies formated debug entries to the user buffer
526  */
527 
528 static ssize_t
debug_output(struct file * file,char __user * user_buf,size_t len,loff_t * offset)529 debug_output(struct file *file,		/* file descriptor */
530 	    char __user *user_buf,	/* user buffer */
531 	    size_t  len,		/* length of buffer */
532 	    loff_t *offset)		/* offset in the file */
533 {
534 	size_t count = 0;
535 	size_t entry_offset;
536 	file_private_info_t *p_info;
537 
538 	p_info = ((file_private_info_t *) file->private_data);
539 	if (*offset != p_info->offset)
540 		return -EPIPE;
541 	if(p_info->act_area >= p_info->debug_info_snap->nr_areas)
542 		return 0;
543 	entry_offset = p_info->act_entry_offset;
544 	while(count < len){
545 		int formatted_line_size;
546 		int formatted_line_residue;
547 		int user_buf_residue;
548 		size_t copy_size;
549 
550 		formatted_line_size = debug_format_entry(p_info);
551 		formatted_line_residue = formatted_line_size - entry_offset;
552 		user_buf_residue = len-count;
553 		copy_size = min(user_buf_residue, formatted_line_residue);
554 		if(copy_size){
555 			if (copy_to_user(user_buf + count, p_info->temp_buf
556 					+ entry_offset, copy_size))
557 				return -EFAULT;
558 			count += copy_size;
559 			entry_offset += copy_size;
560 		}
561 		if(copy_size == formatted_line_residue){
562 			entry_offset = 0;
563 			if(debug_next_entry(p_info))
564 				goto out;
565 		}
566 	}
567 out:
568 	p_info->offset           = *offset + count;
569 	p_info->act_entry_offset = entry_offset;
570 	*offset = p_info->offset;
571 	return count;
572 }
573 
574 /*
575  * debug_input:
576  * - called for user write()
577  * - calls input function of view
578  */
579 
580 static ssize_t
debug_input(struct file * file,const char __user * user_buf,size_t length,loff_t * offset)581 debug_input(struct file *file, const char __user *user_buf, size_t length,
582 		loff_t *offset)
583 {
584 	int rc = 0;
585 	file_private_info_t *p_info;
586 
587 	mutex_lock(&debug_mutex);
588 	p_info = ((file_private_info_t *) file->private_data);
589 	if (p_info->view->input_proc)
590 		rc = p_info->view->input_proc(p_info->debug_info_org,
591 					      p_info->view, file, user_buf,
592 					      length, offset);
593 	else
594 		rc = -EPERM;
595 	mutex_unlock(&debug_mutex);
596 	return rc;		/* number of input characters */
597 }
598 
599 /*
600  * debug_open:
601  * - called for user open()
602  * - copies formated output to private_data area of the file
603  *   handle
604  */
605 
606 static int
debug_open(struct inode * inode,struct file * file)607 debug_open(struct inode *inode, struct file *file)
608 {
609 	int i, rc = 0;
610 	file_private_info_t *p_info;
611 	debug_info_t *debug_info, *debug_info_snapshot;
612 
613 	mutex_lock(&debug_mutex);
614 	debug_info = file_inode(file)->i_private;
615 	/* find debug view */
616 	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
617 		if (!debug_info->views[i])
618 			continue;
619 		else if (debug_info->debugfs_entries[i] ==
620 			 file->f_path.dentry) {
621 			goto found;	/* found view ! */
622 		}
623 	}
624 	/* no entry found */
625 	rc = -EINVAL;
626 	goto out;
627 
628 found:
629 
630 	/* Make snapshot of current debug areas to get it consistent.     */
631 	/* To copy all the areas is only needed, if we have a view which  */
632 	/* formats the debug areas. */
633 
634 	if(!debug_info->views[i]->format_proc &&
635 		!debug_info->views[i]->header_proc){
636 		debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
637 	} else {
638 		debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
639 	}
640 
641 	if(!debug_info_snapshot){
642 		rc = -ENOMEM;
643 		goto out;
644 	}
645 	p_info = kmalloc(sizeof(file_private_info_t),
646 						GFP_KERNEL);
647 	if(!p_info){
648 		debug_info_free(debug_info_snapshot);
649 		rc = -ENOMEM;
650 		goto out;
651 	}
652 	p_info->offset = 0;
653 	p_info->debug_info_snap = debug_info_snapshot;
654 	p_info->debug_info_org  = debug_info;
655 	p_info->view = debug_info->views[i];
656 	p_info->act_area = 0;
657 	p_info->act_page = 0;
658 	p_info->act_entry = DEBUG_PROLOG_ENTRY;
659 	p_info->act_entry_offset = 0;
660 	file->private_data = p_info;
661 	debug_info_get(debug_info);
662 	nonseekable_open(inode, file);
663 out:
664 	mutex_unlock(&debug_mutex);
665 	return rc;
666 }
667 
668 /*
669  * debug_close:
670  * - called for user close()
671  * - deletes  private_data area of the file handle
672  */
673 
674 static int
debug_close(struct inode * inode,struct file * file)675 debug_close(struct inode *inode, struct file *file)
676 {
677 	file_private_info_t *p_info;
678 	p_info = (file_private_info_t *) file->private_data;
679 	if(p_info->debug_info_snap)
680 		debug_info_free(p_info->debug_info_snap);
681 	debug_info_put(p_info->debug_info_org);
682 	kfree(file->private_data);
683 	return 0;		/* success */
684 }
685 
686 /*
687  * debug_register_mode:
688  * - Creates and initializes debug area for the caller
689  *   The mode parameter allows to specify access rights for the s390dbf files
690  * - Returns handle for debug area
691  */
692 
debug_register_mode(const char * name,int pages_per_area,int nr_areas,int buf_size,umode_t mode,uid_t uid,gid_t gid)693 debug_info_t *debug_register_mode(const char *name, int pages_per_area,
694 				  int nr_areas, int buf_size, umode_t mode,
695 				  uid_t uid, gid_t gid)
696 {
697 	debug_info_t *rc = NULL;
698 
699 	/* Since debugfs currently does not support uid/gid other than root, */
700 	/* we do not allow gid/uid != 0 until we get support for that. */
701 	if ((uid != 0) || (gid != 0))
702 		pr_warning("Root becomes the owner of all s390dbf files "
703 			   "in sysfs\n");
704 	BUG_ON(!initialized);
705 	mutex_lock(&debug_mutex);
706 
707         /* create new debug_info */
708 
709 	rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
710 	if(!rc)
711 		goto out;
712 	debug_register_view(rc, &debug_level_view);
713         debug_register_view(rc, &debug_flush_view);
714 	debug_register_view(rc, &debug_pages_view);
715 out:
716         if (!rc){
717 		pr_err("Registering debug feature %s failed\n", name);
718         }
719 	mutex_unlock(&debug_mutex);
720 	return rc;
721 }
722 EXPORT_SYMBOL(debug_register_mode);
723 
724 /*
725  * debug_register:
726  * - creates and initializes debug area for the caller
727  * - returns handle for debug area
728  */
729 
debug_register(const char * name,int pages_per_area,int nr_areas,int buf_size)730 debug_info_t *debug_register(const char *name, int pages_per_area,
731 			     int nr_areas, int buf_size)
732 {
733 	return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
734 				   S_IRUSR | S_IWUSR, 0, 0);
735 }
736 EXPORT_SYMBOL(debug_register);
737 
738 /*
739  * debug_unregister:
740  * - give back debug area
741  */
742 
743 void
debug_unregister(debug_info_t * id)744 debug_unregister(debug_info_t * id)
745 {
746 	if (!id)
747 		goto out;
748 	mutex_lock(&debug_mutex);
749 	debug_info_put(id);
750 	mutex_unlock(&debug_mutex);
751 
752 out:
753 	return;
754 }
755 EXPORT_SYMBOL(debug_unregister);
756 
757 /*
758  * debug_set_size:
759  * - set area size (number of pages) and number of areas
760  */
761 static int
debug_set_size(debug_info_t * id,int nr_areas,int pages_per_area)762 debug_set_size(debug_info_t* id, int nr_areas, int pages_per_area)
763 {
764 	unsigned long flags;
765 	debug_entry_t *** new_areas;
766 	int rc=0;
767 
768 	if(!id || (nr_areas <= 0) || (pages_per_area < 0))
769 		return -EINVAL;
770 	if(pages_per_area > 0){
771 		new_areas = debug_areas_alloc(pages_per_area, nr_areas);
772 		if(!new_areas) {
773 			pr_info("Allocating memory for %i pages failed\n",
774 				pages_per_area);
775 			rc = -ENOMEM;
776 			goto out;
777 		}
778 	} else {
779 		new_areas = NULL;
780 	}
781 	spin_lock_irqsave(&id->lock,flags);
782 	debug_areas_free(id);
783 	id->areas = new_areas;
784 	id->nr_areas = nr_areas;
785 	id->pages_per_area = pages_per_area;
786 	id->active_area = 0;
787 	memset(id->active_entries,0,sizeof(int)*id->nr_areas);
788 	memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
789 	spin_unlock_irqrestore(&id->lock,flags);
790 	pr_info("%s: set new size (%i pages)\n" ,id->name, pages_per_area);
791 out:
792 	return rc;
793 }
794 
795 /*
796  * debug_set_level:
797  * - set actual debug level
798  */
799 
800 void
debug_set_level(debug_info_t * id,int new_level)801 debug_set_level(debug_info_t* id, int new_level)
802 {
803 	unsigned long flags;
804 	if(!id)
805 		return;
806 	spin_lock_irqsave(&id->lock,flags);
807         if(new_level == DEBUG_OFF_LEVEL){
808                 id->level = DEBUG_OFF_LEVEL;
809 		pr_info("%s: switched off\n",id->name);
810         } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
811 		pr_info("%s: level %i is out of range (%i - %i)\n",
812                         id->name, new_level, 0, DEBUG_MAX_LEVEL);
813         } else {
814                 id->level = new_level;
815         }
816 	spin_unlock_irqrestore(&id->lock,flags);
817 }
818 EXPORT_SYMBOL(debug_set_level);
819 
820 /*
821  * proceed_active_entry:
822  * - set active entry to next in the ring buffer
823  */
824 
825 static inline void
proceed_active_entry(debug_info_t * id)826 proceed_active_entry(debug_info_t * id)
827 {
828 	if ((id->active_entries[id->active_area] += id->entry_size)
829 	    > (PAGE_SIZE - id->entry_size)){
830 		id->active_entries[id->active_area] = 0;
831 		id->active_pages[id->active_area] =
832 			(id->active_pages[id->active_area] + 1) %
833 			id->pages_per_area;
834 	}
835 }
836 
837 /*
838  * proceed_active_area:
839  * - set active area to next in the ring buffer
840  */
841 
842 static inline void
proceed_active_area(debug_info_t * id)843 proceed_active_area(debug_info_t * id)
844 {
845 	id->active_area++;
846 	id->active_area = id->active_area % id->nr_areas;
847 }
848 
849 /*
850  * get_active_entry:
851  */
852 
853 static inline debug_entry_t*
get_active_entry(debug_info_t * id)854 get_active_entry(debug_info_t * id)
855 {
856 	return (debug_entry_t *) (((char *) id->areas[id->active_area]
857 					[id->active_pages[id->active_area]]) +
858 					id->active_entries[id->active_area]);
859 }
860 
861 /*
862  * debug_finish_entry:
863  * - set timestamp, caller address, cpu number etc.
864  */
865 
866 static inline void
debug_finish_entry(debug_info_t * id,debug_entry_t * active,int level,int exception)867 debug_finish_entry(debug_info_t * id, debug_entry_t* active, int level,
868 			int exception)
869 {
870 	active->id.stck = get_tod_clock_fast();
871 	active->id.fields.cpuid = smp_processor_id();
872 	active->caller = __builtin_return_address(0);
873 	active->id.fields.exception = exception;
874 	active->id.fields.level     = level;
875 	proceed_active_entry(id);
876 	if(exception)
877 		proceed_active_area(id);
878 }
879 
880 static int debug_stoppable=1;
881 static int debug_active=1;
882 
883 #define CTL_S390DBF_STOPPABLE 5678
884 #define CTL_S390DBF_ACTIVE 5679
885 
886 /*
887  * proc handler for the running debug_active sysctl
888  * always allow read, allow write only if debug_stoppable is set or
889  * if debug_active is already off
890  */
891 static int
s390dbf_procactive(struct ctl_table * table,int write,void __user * buffer,size_t * lenp,loff_t * ppos)892 s390dbf_procactive(struct ctl_table *table, int write,
893                      void __user *buffer, size_t *lenp, loff_t *ppos)
894 {
895 	if (!write || debug_stoppable || !debug_active)
896 		return proc_dointvec(table, write, buffer, lenp, ppos);
897 	else
898 		return 0;
899 }
900 
901 
902 static struct ctl_table s390dbf_table[] = {
903 	{
904 		.procname       = "debug_stoppable",
905 		.data		= &debug_stoppable,
906 		.maxlen		= sizeof(int),
907 		.mode           = S_IRUGO | S_IWUSR,
908 		.proc_handler   = proc_dointvec,
909 	},
910 	 {
911 		.procname       = "debug_active",
912 		.data		= &debug_active,
913 		.maxlen		= sizeof(int),
914 		.mode           = S_IRUGO | S_IWUSR,
915 		.proc_handler   = s390dbf_procactive,
916 	},
917 	{ }
918 };
919 
920 static struct ctl_table s390dbf_dir_table[] = {
921 	{
922 		.procname       = "s390dbf",
923 		.maxlen         = 0,
924 		.mode           = S_IRUGO | S_IXUGO,
925 		.child          = s390dbf_table,
926 	},
927 	{ }
928 };
929 
930 static struct ctl_table_header *s390dbf_sysctl_header;
931 
932 void
debug_stop_all(void)933 debug_stop_all(void)
934 {
935 	if (debug_stoppable)
936 		debug_active = 0;
937 }
938 EXPORT_SYMBOL(debug_stop_all);
939 
debug_set_critical(void)940 void debug_set_critical(void)
941 {
942 	debug_critical = 1;
943 }
944 
945 /*
946  * debug_event_common:
947  * - write debug entry with given size
948  */
949 
950 debug_entry_t*
debug_event_common(debug_info_t * id,int level,const void * buf,int len)951 debug_event_common(debug_info_t * id, int level, const void *buf, int len)
952 {
953 	unsigned long flags;
954 	debug_entry_t *active;
955 
956 	if (!debug_active || !id->areas)
957 		return NULL;
958 	if (debug_critical) {
959 		if (!spin_trylock_irqsave(&id->lock, flags))
960 			return NULL;
961 	} else
962 		spin_lock_irqsave(&id->lock, flags);
963 	active = get_active_entry(id);
964 	memset(DEBUG_DATA(active), 0, id->buf_size);
965 	memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
966 	debug_finish_entry(id, active, level, 0);
967 	spin_unlock_irqrestore(&id->lock, flags);
968 
969 	return active;
970 }
971 EXPORT_SYMBOL(debug_event_common);
972 
973 /*
974  * debug_exception_common:
975  * - write debug entry with given size and switch to next debug area
976  */
977 
978 debug_entry_t
debug_exception_common(debug_info_t * id,int level,const void * buf,int len)979 *debug_exception_common(debug_info_t * id, int level, const void *buf, int len)
980 {
981 	unsigned long flags;
982 	debug_entry_t *active;
983 
984 	if (!debug_active || !id->areas)
985 		return NULL;
986 	if (debug_critical) {
987 		if (!spin_trylock_irqsave(&id->lock, flags))
988 			return NULL;
989 	} else
990 		spin_lock_irqsave(&id->lock, flags);
991 	active = get_active_entry(id);
992 	memset(DEBUG_DATA(active), 0, id->buf_size);
993 	memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
994 	debug_finish_entry(id, active, level, 1);
995 	spin_unlock_irqrestore(&id->lock, flags);
996 
997 	return active;
998 }
999 EXPORT_SYMBOL(debug_exception_common);
1000 
1001 /*
1002  * counts arguments in format string for sprintf view
1003  */
1004 
1005 static inline int
debug_count_numargs(char * string)1006 debug_count_numargs(char *string)
1007 {
1008 	int numargs=0;
1009 
1010 	while(*string) {
1011 		if(*string++=='%')
1012 			numargs++;
1013 	}
1014 	return(numargs);
1015 }
1016 
1017 /*
1018  * debug_sprintf_event:
1019  */
1020 
1021 debug_entry_t*
__debug_sprintf_event(debug_info_t * id,int level,char * string,...)1022 __debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1023 {
1024 	va_list   ap;
1025 	int numargs,idx;
1026 	unsigned long flags;
1027 	debug_sprintf_entry_t *curr_event;
1028 	debug_entry_t *active;
1029 
1030 	if (!debug_active || !id->areas)
1031 		return NULL;
1032 	numargs=debug_count_numargs(string);
1033 
1034 	if (debug_critical) {
1035 		if (!spin_trylock_irqsave(&id->lock, flags))
1036 			return NULL;
1037 	} else
1038 		spin_lock_irqsave(&id->lock, flags);
1039 	active = get_active_entry(id);
1040 	curr_event=(debug_sprintf_entry_t *) DEBUG_DATA(active);
1041 	va_start(ap,string);
1042 	curr_event->string=string;
1043 	for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1044 		curr_event->args[idx]=va_arg(ap,long);
1045 	va_end(ap);
1046 	debug_finish_entry(id, active, level, 0);
1047 	spin_unlock_irqrestore(&id->lock, flags);
1048 
1049 	return active;
1050 }
1051 EXPORT_SYMBOL(__debug_sprintf_event);
1052 
1053 /*
1054  * debug_sprintf_exception:
1055  */
1056 
1057 debug_entry_t*
__debug_sprintf_exception(debug_info_t * id,int level,char * string,...)1058 __debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1059 {
1060 	va_list   ap;
1061 	int numargs,idx;
1062 	unsigned long flags;
1063 	debug_sprintf_entry_t *curr_event;
1064 	debug_entry_t *active;
1065 
1066 	if (!debug_active || !id->areas)
1067 		return NULL;
1068 
1069 	numargs=debug_count_numargs(string);
1070 
1071 	if (debug_critical) {
1072 		if (!spin_trylock_irqsave(&id->lock, flags))
1073 			return NULL;
1074 	} else
1075 		spin_lock_irqsave(&id->lock, flags);
1076 	active = get_active_entry(id);
1077 	curr_event=(debug_sprintf_entry_t *)DEBUG_DATA(active);
1078 	va_start(ap,string);
1079 	curr_event->string=string;
1080 	for(idx=0;idx<min(numargs,(int)(id->buf_size / sizeof(long))-1);idx++)
1081 		curr_event->args[idx]=va_arg(ap,long);
1082 	va_end(ap);
1083 	debug_finish_entry(id, active, level, 1);
1084 	spin_unlock_irqrestore(&id->lock, flags);
1085 
1086 	return active;
1087 }
1088 EXPORT_SYMBOL(__debug_sprintf_exception);
1089 
1090 /*
1091  * debug_register_view:
1092  */
1093 
1094 int
debug_register_view(debug_info_t * id,struct debug_view * view)1095 debug_register_view(debug_info_t * id, struct debug_view *view)
1096 {
1097 	int rc = 0;
1098 	int i;
1099 	unsigned long flags;
1100 	umode_t mode;
1101 	struct dentry *pde;
1102 
1103 	if (!id)
1104 		goto out;
1105 	mode = (id->mode | S_IFREG) & ~S_IXUGO;
1106 	if (!(view->prolog_proc || view->format_proc || view->header_proc))
1107 		mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1108 	if (!view->input_proc)
1109 		mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1110 	pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1111 				id , &debug_file_ops);
1112 	if (!pde){
1113 		pr_err("Registering view %s/%s failed due to out of "
1114 		       "memory\n", id->name,view->name);
1115 		rc = -1;
1116 		goto out;
1117 	}
1118 	spin_lock_irqsave(&id->lock, flags);
1119 	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1120 		if (!id->views[i])
1121 			break;
1122 	}
1123 	if (i == DEBUG_MAX_VIEWS) {
1124 		pr_err("Registering view %s/%s would exceed the maximum "
1125 		       "number of views %i\n", id->name, view->name, i);
1126 		rc = -1;
1127 	} else {
1128 		id->views[i] = view;
1129 		id->debugfs_entries[i] = pde;
1130 	}
1131 	spin_unlock_irqrestore(&id->lock, flags);
1132 	if (rc)
1133 		debugfs_remove(pde);
1134 out:
1135 	return rc;
1136 }
1137 EXPORT_SYMBOL(debug_register_view);
1138 
1139 /*
1140  * debug_unregister_view:
1141  */
1142 
1143 int
debug_unregister_view(debug_info_t * id,struct debug_view * view)1144 debug_unregister_view(debug_info_t * id, struct debug_view *view)
1145 {
1146 	struct dentry *dentry = NULL;
1147 	unsigned long flags;
1148 	int i, rc = 0;
1149 
1150 	if (!id)
1151 		goto out;
1152 	spin_lock_irqsave(&id->lock, flags);
1153 	for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1154 		if (id->views[i] == view)
1155 			break;
1156 	}
1157 	if (i == DEBUG_MAX_VIEWS)
1158 		rc = -1;
1159 	else {
1160 		dentry = id->debugfs_entries[i];
1161 		id->views[i] = NULL;
1162 		id->debugfs_entries[i] = NULL;
1163 	}
1164 	spin_unlock_irqrestore(&id->lock, flags);
1165 	debugfs_remove(dentry);
1166 out:
1167 	return rc;
1168 }
1169 EXPORT_SYMBOL(debug_unregister_view);
1170 
1171 static inline char *
debug_get_user_string(const char __user * user_buf,size_t user_len)1172 debug_get_user_string(const char __user *user_buf, size_t user_len)
1173 {
1174 	char* buffer;
1175 
1176 	buffer = kmalloc(user_len + 1, GFP_KERNEL);
1177 	if (!buffer)
1178 		return ERR_PTR(-ENOMEM);
1179 	if (copy_from_user(buffer, user_buf, user_len) != 0) {
1180 		kfree(buffer);
1181 		return ERR_PTR(-EFAULT);
1182 	}
1183 	/* got the string, now strip linefeed. */
1184 	if (buffer[user_len - 1] == '\n')
1185 		buffer[user_len - 1] = 0;
1186 	else
1187 		buffer[user_len] = 0;
1188         return buffer;
1189 }
1190 
1191 static inline int
debug_get_uint(char * buf)1192 debug_get_uint(char *buf)
1193 {
1194 	int rc;
1195 
1196 	buf = skip_spaces(buf);
1197 	rc = simple_strtoul(buf, &buf, 10);
1198 	if(*buf){
1199 		rc = -EINVAL;
1200 	}
1201 	return rc;
1202 }
1203 
1204 /*
1205  * functions for debug-views
1206  ***********************************
1207 */
1208 
1209 /*
1210  * prints out actual debug level
1211  */
1212 
1213 static int
debug_prolog_pages_fn(debug_info_t * id,struct debug_view * view,char * out_buf)1214 debug_prolog_pages_fn(debug_info_t * id,
1215 				 struct debug_view *view, char *out_buf)
1216 {
1217 	return sprintf(out_buf, "%i\n", id->pages_per_area);
1218 }
1219 
1220 /*
1221  * reads new size (number of pages per debug area)
1222  */
1223 
1224 static int
debug_input_pages_fn(debug_info_t * id,struct debug_view * view,struct file * file,const char __user * user_buf,size_t user_len,loff_t * offset)1225 debug_input_pages_fn(debug_info_t * id, struct debug_view *view,
1226 			struct file *file, const char __user *user_buf,
1227 			size_t user_len, loff_t * offset)
1228 {
1229 	char *str;
1230 	int rc,new_pages;
1231 
1232 	if (user_len > 0x10000)
1233                 user_len = 0x10000;
1234 	if (*offset != 0){
1235 		rc = -EPIPE;
1236 		goto out;
1237 	}
1238 	str = debug_get_user_string(user_buf,user_len);
1239 	if(IS_ERR(str)){
1240 		rc = PTR_ERR(str);
1241 		goto out;
1242 	}
1243 	new_pages = debug_get_uint(str);
1244 	if(new_pages < 0){
1245 		rc = -EINVAL;
1246 		goto free_str;
1247 	}
1248 	rc = debug_set_size(id,id->nr_areas, new_pages);
1249 	if(rc != 0){
1250 		rc = -EINVAL;
1251 		goto free_str;
1252 	}
1253 	rc = user_len;
1254 free_str:
1255 	kfree(str);
1256 out:
1257 	*offset += user_len;
1258 	return rc;		/* number of input characters */
1259 }
1260 
1261 /*
1262  * prints out actual debug level
1263  */
1264 
1265 static int
debug_prolog_level_fn(debug_info_t * id,struct debug_view * view,char * out_buf)1266 debug_prolog_level_fn(debug_info_t * id, struct debug_view *view, char *out_buf)
1267 {
1268 	int rc = 0;
1269 
1270 	if(id->level == DEBUG_OFF_LEVEL) {
1271 		rc = sprintf(out_buf,"-\n");
1272 	}
1273 	else {
1274 		rc = sprintf(out_buf, "%i\n", id->level);
1275 	}
1276 	return rc;
1277 }
1278 
1279 /*
1280  * reads new debug level
1281  */
1282 
1283 static int
debug_input_level_fn(debug_info_t * id,struct debug_view * view,struct file * file,const char __user * user_buf,size_t user_len,loff_t * offset)1284 debug_input_level_fn(debug_info_t * id, struct debug_view *view,
1285 			struct file *file, const char __user *user_buf,
1286 			size_t user_len, loff_t * offset)
1287 {
1288 	char *str;
1289 	int rc,new_level;
1290 
1291 	if (user_len > 0x10000)
1292                 user_len = 0x10000;
1293 	if (*offset != 0){
1294 		rc = -EPIPE;
1295 		goto out;
1296 	}
1297 	str = debug_get_user_string(user_buf,user_len);
1298 	if(IS_ERR(str)){
1299 		rc = PTR_ERR(str);
1300 		goto out;
1301 	}
1302 	if(str[0] == '-'){
1303 		debug_set_level(id, DEBUG_OFF_LEVEL);
1304 		rc = user_len;
1305 		goto free_str;
1306 	} else {
1307 		new_level = debug_get_uint(str);
1308 	}
1309 	if(new_level < 0) {
1310 		pr_warning("%s is not a valid level for a debug "
1311 			   "feature\n", str);
1312 		rc = -EINVAL;
1313 	} else {
1314 		debug_set_level(id, new_level);
1315 		rc = user_len;
1316 	}
1317 free_str:
1318 	kfree(str);
1319 out:
1320 	*offset += user_len;
1321 	return rc;		/* number of input characters */
1322 }
1323 
1324 
1325 /*
1326  * flushes debug areas
1327  */
1328 
debug_flush(debug_info_t * id,int area)1329 static void debug_flush(debug_info_t* id, int area)
1330 {
1331         unsigned long flags;
1332         int i,j;
1333 
1334         if(!id || !id->areas)
1335                 return;
1336         spin_lock_irqsave(&id->lock,flags);
1337         if(area == DEBUG_FLUSH_ALL){
1338                 id->active_area = 0;
1339                 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1340                 for (i = 0; i < id->nr_areas; i++) {
1341 			id->active_pages[i] = 0;
1342 			for(j = 0; j < id->pages_per_area; j++) {
1343                         	memset(id->areas[i][j], 0, PAGE_SIZE);
1344 			}
1345 		}
1346         } else if(area >= 0 && area < id->nr_areas) {
1347                 id->active_entries[area] = 0;
1348 		id->active_pages[area] = 0;
1349 		for(i = 0; i < id->pages_per_area; i++) {
1350                 	memset(id->areas[area][i],0,PAGE_SIZE);
1351 		}
1352         }
1353         spin_unlock_irqrestore(&id->lock,flags);
1354 }
1355 
1356 /*
1357  * view function: flushes debug areas
1358  */
1359 
1360 static int
debug_input_flush_fn(debug_info_t * id,struct debug_view * view,struct file * file,const char __user * user_buf,size_t user_len,loff_t * offset)1361 debug_input_flush_fn(debug_info_t * id, struct debug_view *view,
1362 			struct file *file, const char __user *user_buf,
1363 			size_t user_len, loff_t * offset)
1364 {
1365         char input_buf[1];
1366         int rc = user_len;
1367 
1368 	if (user_len > 0x10000)
1369                 user_len = 0x10000;
1370         if (*offset != 0){
1371 		rc = -EPIPE;
1372                 goto out;
1373 	}
1374         if (copy_from_user(input_buf, user_buf, 1)){
1375                 rc = -EFAULT;
1376                 goto out;
1377         }
1378         if(input_buf[0] == '-') {
1379                 debug_flush(id, DEBUG_FLUSH_ALL);
1380                 goto out;
1381         }
1382         if (isdigit(input_buf[0])) {
1383                 int area = ((int) input_buf[0] - (int) '0');
1384                 debug_flush(id, area);
1385                 goto out;
1386         }
1387 
1388 	pr_info("Flushing debug data failed because %c is not a valid "
1389 		 "area\n", input_buf[0]);
1390 
1391 out:
1392         *offset += user_len;
1393         return rc;              /* number of input characters */
1394 }
1395 
1396 /*
1397  * prints debug header in raw format
1398  */
1399 
1400 static int
debug_raw_header_fn(debug_info_t * id,struct debug_view * view,int area,debug_entry_t * entry,char * out_buf)1401 debug_raw_header_fn(debug_info_t * id, struct debug_view *view,
1402 			int area, debug_entry_t * entry, char *out_buf)
1403 {
1404         int rc;
1405 
1406 	rc = sizeof(debug_entry_t);
1407 	memcpy(out_buf,entry,sizeof(debug_entry_t));
1408         return rc;
1409 }
1410 
1411 /*
1412  * prints debug data in raw format
1413  */
1414 
1415 static int
debug_raw_format_fn(debug_info_t * id,struct debug_view * view,char * out_buf,const char * in_buf)1416 debug_raw_format_fn(debug_info_t * id, struct debug_view *view,
1417 			       char *out_buf, const char *in_buf)
1418 {
1419 	int rc;
1420 
1421 	rc = id->buf_size;
1422 	memcpy(out_buf, in_buf, id->buf_size);
1423 	return rc;
1424 }
1425 
1426 /*
1427  * prints debug data in hex/ascii format
1428  */
1429 
1430 static int
debug_hex_ascii_format_fn(debug_info_t * id,struct debug_view * view,char * out_buf,const char * in_buf)1431 debug_hex_ascii_format_fn(debug_info_t * id, struct debug_view *view,
1432 	    		  char *out_buf, const char *in_buf)
1433 {
1434 	int i, rc = 0;
1435 
1436 	for (i = 0; i < id->buf_size; i++) {
1437                 rc += sprintf(out_buf + rc, "%02x ",
1438                               ((unsigned char *) in_buf)[i]);
1439         }
1440 	rc += sprintf(out_buf + rc, "| ");
1441 	for (i = 0; i < id->buf_size; i++) {
1442 		unsigned char c = in_buf[i];
1443 		if (isascii(c) && isprint(c))
1444 			rc += sprintf(out_buf + rc, "%c", c);
1445 		else
1446 			rc += sprintf(out_buf + rc, ".");
1447 	}
1448 	rc += sprintf(out_buf + rc, "\n");
1449 	return rc;
1450 }
1451 
1452 /*
1453  * prints header for debug entry
1454  */
1455 
1456 int
debug_dflt_header_fn(debug_info_t * id,struct debug_view * view,int area,debug_entry_t * entry,char * out_buf)1457 debug_dflt_header_fn(debug_info_t * id, struct debug_view *view,
1458 			 int area, debug_entry_t * entry, char *out_buf)
1459 {
1460 	struct timespec64 time_spec;
1461 	char *except_str;
1462 	unsigned long caller;
1463 	int rc = 0;
1464 	unsigned int level;
1465 
1466 	level = entry->id.fields.level;
1467 	stck_to_timespec64(entry->id.stck, &time_spec);
1468 
1469 	if (entry->id.fields.exception)
1470 		except_str = "*";
1471 	else
1472 		except_str = "-";
1473 	caller = ((unsigned long) entry->caller) & PSW_ADDR_INSN;
1474 	rc += sprintf(out_buf, "%02i %011lld:%06lu %1u %1s %02i %p  ",
1475 		      area, (long long)time_spec.tv_sec,
1476 		      time_spec.tv_nsec / 1000, level, except_str,
1477 		      entry->id.fields.cpuid, (void *)caller);
1478 	return rc;
1479 }
1480 EXPORT_SYMBOL(debug_dflt_header_fn);
1481 
1482 /*
1483  * prints debug data sprintf-formated:
1484  * debug_sprinf_event/exception calls must be used together with this view
1485  */
1486 
1487 #define DEBUG_SPRINTF_MAX_ARGS 10
1488 
1489 static int
debug_sprintf_format_fn(debug_info_t * id,struct debug_view * view,char * out_buf,debug_sprintf_entry_t * curr_event)1490 debug_sprintf_format_fn(debug_info_t * id, struct debug_view *view,
1491                         char *out_buf, debug_sprintf_entry_t *curr_event)
1492 {
1493 	int num_longs, num_used_args = 0,i, rc = 0;
1494 	int index[DEBUG_SPRINTF_MAX_ARGS];
1495 
1496 	/* count of longs fit into one entry */
1497 	num_longs = id->buf_size /  sizeof(long);
1498 
1499 	if(num_longs < 1)
1500 		goto out; /* bufsize of entry too small */
1501 	if(num_longs == 1) {
1502 		/* no args, we use only the string */
1503 		strcpy(out_buf, curr_event->string);
1504 		rc = strlen(curr_event->string);
1505 		goto out;
1506 	}
1507 
1508 	/* number of arguments used for sprintf (without the format string) */
1509 	num_used_args   = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1510 
1511 	memset(index,0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1512 
1513 	for(i = 0; i < num_used_args; i++)
1514 		index[i] = i;
1515 
1516 	rc =  sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1517 		curr_event->args[index[1]], curr_event->args[index[2]],
1518 		curr_event->args[index[3]], curr_event->args[index[4]],
1519 		curr_event->args[index[5]], curr_event->args[index[6]],
1520 		curr_event->args[index[7]], curr_event->args[index[8]],
1521 		curr_event->args[index[9]]);
1522 
1523 out:
1524 
1525 	return rc;
1526 }
1527 
1528 /*
1529  * debug_init:
1530  * - is called exactly once to initialize the debug feature
1531  */
debug_init(void)1532 static int __init debug_init(void)
1533 {
1534 	s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1535 	mutex_lock(&debug_mutex);
1536 	debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1537 	initialized = 1;
1538 	mutex_unlock(&debug_mutex);
1539 	return 0;
1540 }
1541 postcore_initcall(debug_init);
1542