blob: 75ca78f3a8c9bc39cb60bcad14535b7978f52e00 [file] [log] [blame]
Jason Barone9d376f2009-02-05 11:51:38 -05001/*
2 * lib/dynamic_debug.c
3 *
4 * make pr_debug()/dev_dbg() calls runtime configurable based upon their
5 * source module.
6 *
7 * Copyright (C) 2008 Jason Baron <jbaron@redhat.com>
8 * By Greg Banks <gnb@melbourne.sgi.com>
9 * Copyright (c) 2008 Silicon Graphics Inc. All Rights Reserved.
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010010 * Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
Jason Barone9d376f2009-02-05 11:51:38 -050011 */
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/moduleparam.h>
16#include <linux/kallsyms.h>
17#include <linux/version.h>
18#include <linux/types.h>
19#include <linux/mutex.h>
20#include <linux/proc_fs.h>
21#include <linux/seq_file.h>
22#include <linux/list.h>
23#include <linux/sysctl.h>
24#include <linux/ctype.h>
André Goddard Rosae7d28602009-12-14 18:01:06 -080025#include <linux/string.h>
Jason Barone9d376f2009-02-05 11:51:38 -050026#include <linux/uaccess.h>
27#include <linux/dynamic_debug.h>
28#include <linux/debugfs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Jason Baron52159d92010-09-17 11:09:17 -040030#include <linux/jump_label.h>
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010031#include <linux/hardirq.h>
Greg Kroah-Hartmane8d97922011-02-03 15:59:58 -080032#include <linux/sched.h>
Jason Barone9d376f2009-02-05 11:51:38 -050033
34extern struct _ddebug __start___verbose[];
35extern struct _ddebug __stop___verbose[];
36
Jason Barone9d376f2009-02-05 11:51:38 -050037struct ddebug_table {
38 struct list_head link;
39 char *mod_name;
40 unsigned int num_ddebugs;
41 unsigned int num_enabled;
42 struct _ddebug *ddebugs;
43};
44
45struct ddebug_query {
46 const char *filename;
47 const char *module;
48 const char *function;
49 const char *format;
50 unsigned int first_lineno, last_lineno;
51};
52
53struct ddebug_iter {
54 struct ddebug_table *table;
55 unsigned int idx;
56};
57
58static DEFINE_MUTEX(ddebug_lock);
59static LIST_HEAD(ddebug_tables);
60static int verbose = 0;
61
62/* Return the last part of a pathname */
63static inline const char *basename(const char *path)
64{
65 const char *tail = strrchr(path, '/');
66 return tail ? tail+1 : path;
67}
68
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010069static struct { unsigned flag:8; char opt_char; } opt_array[] = {
70 { _DPRINTK_FLAGS_PRINT, 'p' },
71 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
72 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
73 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
74 { _DPRINTK_FLAGS_INCL_TID, 't' },
75};
76
Jason Barone9d376f2009-02-05 11:51:38 -050077/* format a string into buf[] which describes the _ddebug's flags */
78static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
79 size_t maxlen)
80{
81 char *p = buf;
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010082 int i;
Jason Barone9d376f2009-02-05 11:51:38 -050083
84 BUG_ON(maxlen < 4);
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +010085 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
86 if (dp->flags & opt_array[i].flag)
87 *p++ = opt_array[i].opt_char;
Jason Barone9d376f2009-02-05 11:51:38 -050088 if (p == buf)
89 *p++ = '-';
90 *p = '\0';
91
92 return buf;
93}
94
95/*
Jason Barone9d376f2009-02-05 11:51:38 -050096 * Search the tables for _ddebug's which match the given
97 * `query' and apply the `flags' and `mask' to them. Tells
98 * the user which ddebug's were changed, or whether none
99 * were matched.
100 */
101static void ddebug_change(const struct ddebug_query *query,
102 unsigned int flags, unsigned int mask)
103{
104 int i;
105 struct ddebug_table *dt;
106 unsigned int newflags;
107 unsigned int nfound = 0;
108 char flagbuf[8];
109
110 /* search for matching ddebugs */
111 mutex_lock(&ddebug_lock);
112 list_for_each_entry(dt, &ddebug_tables, link) {
113
114 /* match against the module name */
115 if (query->module != NULL &&
116 strcmp(query->module, dt->mod_name))
117 continue;
118
119 for (i = 0 ; i < dt->num_ddebugs ; i++) {
120 struct _ddebug *dp = &dt->ddebugs[i];
121
122 /* match against the source filename */
123 if (query->filename != NULL &&
124 strcmp(query->filename, dp->filename) &&
125 strcmp(query->filename, basename(dp->filename)))
126 continue;
127
128 /* match against the function */
129 if (query->function != NULL &&
130 strcmp(query->function, dp->function))
131 continue;
132
133 /* match against the format */
134 if (query->format != NULL &&
135 strstr(dp->format, query->format) == NULL)
136 continue;
137
138 /* match against the line number range */
139 if (query->first_lineno &&
140 dp->lineno < query->first_lineno)
141 continue;
142 if (query->last_lineno &&
143 dp->lineno > query->last_lineno)
144 continue;
145
146 nfound++;
147
148 newflags = (dp->flags & mask) | flags;
149 if (newflags == dp->flags)
150 continue;
151
152 if (!newflags)
153 dt->num_enabled--;
Roel Kluin4df7b3e2009-07-15 20:29:07 +0200154 else if (!dp->flags)
Jason Barone9d376f2009-02-05 11:51:38 -0500155 dt->num_enabled++;
156 dp->flags = newflags;
Jason Baron2d75af22011-01-07 13:36:58 -0500157 if (newflags)
158 dp->enabled = 1;
159 else
160 dp->enabled = 0;
Jason Barone9d376f2009-02-05 11:51:38 -0500161 if (verbose)
162 printk(KERN_INFO
163 "ddebug: changed %s:%d [%s]%s %s\n",
164 dp->filename, dp->lineno,
165 dt->mod_name, dp->function,
166 ddebug_describe_flags(dp, flagbuf,
167 sizeof(flagbuf)));
168 }
169 }
170 mutex_unlock(&ddebug_lock);
171
172 if (!nfound && verbose)
173 printk(KERN_INFO "ddebug: no matches for query\n");
174}
175
176/*
Jason Barone9d376f2009-02-05 11:51:38 -0500177 * Split the buffer `buf' into space-separated words.
Greg Banks9898abb2009-02-06 12:54:26 +1100178 * Handles simple " and ' quoting, i.e. without nested,
179 * embedded or escaped \". Return the number of words
180 * or <0 on error.
Jason Barone9d376f2009-02-05 11:51:38 -0500181 */
182static int ddebug_tokenize(char *buf, char *words[], int maxwords)
183{
184 int nwords = 0;
185
Greg Banks9898abb2009-02-06 12:54:26 +1100186 while (*buf) {
187 char *end;
188
189 /* Skip leading whitespace */
André Goddard Rosae7d28602009-12-14 18:01:06 -0800190 buf = skip_spaces(buf);
Greg Banks9898abb2009-02-06 12:54:26 +1100191 if (!*buf)
192 break; /* oh, it was trailing whitespace */
193
194 /* Run `end' over a word, either whitespace separated or quoted */
195 if (*buf == '"' || *buf == '\'') {
196 int quote = *buf++;
197 for (end = buf ; *end && *end != quote ; end++)
198 ;
199 if (!*end)
200 return -EINVAL; /* unclosed quote */
201 } else {
202 for (end = buf ; *end && !isspace(*end) ; end++)
203 ;
204 BUG_ON(end == buf);
205 }
206 /* Here `buf' is the start of the word, `end' is one past the end */
207
208 if (nwords == maxwords)
209 return -EINVAL; /* ran out of words[] before bytes */
210 if (*end)
211 *end++ = '\0'; /* terminate the word */
212 words[nwords++] = buf;
213 buf = end;
214 }
Jason Barone9d376f2009-02-05 11:51:38 -0500215
216 if (verbose) {
217 int i;
218 printk(KERN_INFO "%s: split into words:", __func__);
219 for (i = 0 ; i < nwords ; i++)
220 printk(" \"%s\"", words[i]);
221 printk("\n");
222 }
223
224 return nwords;
225}
226
227/*
228 * Parse a single line number. Note that the empty string ""
229 * is treated as a special case and converted to zero, which
230 * is later treated as a "don't care" value.
231 */
232static inline int parse_lineno(const char *str, unsigned int *val)
233{
234 char *end = NULL;
235 BUG_ON(str == NULL);
236 if (*str == '\0') {
237 *val = 0;
238 return 0;
239 }
240 *val = simple_strtoul(str, &end, 10);
241 return end == NULL || end == str || *end != '\0' ? -EINVAL : 0;
242}
243
244/*
245 * Undo octal escaping in a string, inplace. This is useful to
246 * allow the user to express a query which matches a format
247 * containing embedded spaces.
248 */
249#define isodigit(c) ((c) >= '0' && (c) <= '7')
250static char *unescape(char *str)
251{
252 char *in = str;
253 char *out = str;
254
255 while (*in) {
256 if (*in == '\\') {
257 if (in[1] == '\\') {
258 *out++ = '\\';
259 in += 2;
260 continue;
261 } else if (in[1] == 't') {
262 *out++ = '\t';
263 in += 2;
264 continue;
265 } else if (in[1] == 'n') {
266 *out++ = '\n';
267 in += 2;
268 continue;
269 } else if (isodigit(in[1]) &&
270 isodigit(in[2]) &&
271 isodigit(in[3])) {
272 *out++ = ((in[1] - '0')<<6) |
273 ((in[2] - '0')<<3) |
274 (in[3] - '0');
275 in += 4;
276 continue;
277 }
278 }
279 *out++ = *in++;
280 }
281 *out = '\0';
282
283 return str;
284}
285
286/*
287 * Parse words[] as a ddebug query specification, which is a series
288 * of (keyword, value) pairs chosen from these possibilities:
289 *
290 * func <function-name>
291 * file <full-pathname>
292 * file <base-filename>
293 * module <module-name>
294 * format <escaped-string-to-find-in-format>
295 * line <lineno>
296 * line <first-lineno>-<last-lineno> // where either may be empty
297 */
298static int ddebug_parse_query(char *words[], int nwords,
299 struct ddebug_query *query)
300{
301 unsigned int i;
302
303 /* check we have an even number of words */
304 if (nwords % 2 != 0)
305 return -EINVAL;
306 memset(query, 0, sizeof(*query));
307
308 for (i = 0 ; i < nwords ; i += 2) {
309 if (!strcmp(words[i], "func"))
310 query->function = words[i+1];
311 else if (!strcmp(words[i], "file"))
312 query->filename = words[i+1];
313 else if (!strcmp(words[i], "module"))
314 query->module = words[i+1];
315 else if (!strcmp(words[i], "format"))
316 query->format = unescape(words[i+1]);
317 else if (!strcmp(words[i], "line")) {
318 char *first = words[i+1];
319 char *last = strchr(first, '-');
320 if (last)
321 *last++ = '\0';
322 if (parse_lineno(first, &query->first_lineno) < 0)
323 return -EINVAL;
324 if (last != NULL) {
325 /* range <first>-<last> */
326 if (parse_lineno(last, &query->last_lineno) < 0)
327 return -EINVAL;
328 } else {
329 query->last_lineno = query->first_lineno;
330 }
331 } else {
332 if (verbose)
333 printk(KERN_ERR "%s: unknown keyword \"%s\"\n",
334 __func__, words[i]);
335 return -EINVAL;
336 }
337 }
338
339 if (verbose)
340 printk(KERN_INFO "%s: q->function=\"%s\" q->filename=\"%s\" "
341 "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
342 __func__, query->function, query->filename,
343 query->module, query->format, query->first_lineno,
344 query->last_lineno);
345
346 return 0;
347}
348
349/*
350 * Parse `str' as a flags specification, format [-+=][p]+.
351 * Sets up *maskp and *flagsp to be used when changing the
352 * flags fields of matched _ddebug's. Returns 0 on success
353 * or <0 on error.
354 */
355static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
356 unsigned int *maskp)
357{
358 unsigned flags = 0;
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100359 int op = '=', i;
Jason Barone9d376f2009-02-05 11:51:38 -0500360
361 switch (*str) {
362 case '+':
363 case '-':
364 case '=':
365 op = *str++;
366 break;
367 default:
368 return -EINVAL;
369 }
370 if (verbose)
371 printk(KERN_INFO "%s: op='%c'\n", __func__, op);
372
373 for ( ; *str ; ++str) {
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100374 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
375 if (*str == opt_array[i].opt_char) {
376 flags |= opt_array[i].flag;
377 break;
378 }
Jason Barone9d376f2009-02-05 11:51:38 -0500379 }
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100380 if (i < 0)
381 return -EINVAL;
Jason Barone9d376f2009-02-05 11:51:38 -0500382 }
383 if (flags == 0)
384 return -EINVAL;
385 if (verbose)
386 printk(KERN_INFO "%s: flags=0x%x\n", __func__, flags);
387
388 /* calculate final *flagsp, *maskp according to mask and op */
389 switch (op) {
390 case '=':
391 *maskp = 0;
392 *flagsp = flags;
393 break;
394 case '+':
395 *maskp = ~0U;
396 *flagsp = flags;
397 break;
398 case '-':
399 *maskp = ~flags;
400 *flagsp = 0;
401 break;
402 }
403 if (verbose)
404 printk(KERN_INFO "%s: *flagsp=0x%x *maskp=0x%x\n",
405 __func__, *flagsp, *maskp);
406 return 0;
407}
408
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200409static int ddebug_exec_query(char *query_string)
410{
411 unsigned int flags = 0, mask = 0;
412 struct ddebug_query query;
413#define MAXWORDS 9
414 int nwords;
415 char *words[MAXWORDS];
416
417 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
418 if (nwords <= 0)
419 return -EINVAL;
420 if (ddebug_parse_query(words, nwords-1, &query))
421 return -EINVAL;
422 if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
423 return -EINVAL;
424
425 /* actually go and implement the change */
426 ddebug_change(&query, flags, mask);
427 return 0;
428}
429
Bart Van Assche8ba6ebf52011-01-23 17:17:24 +0100430int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
431{
432 va_list args;
433 int res;
434
435 BUG_ON(!descriptor);
436 BUG_ON(!fmt);
437
438 va_start(args, fmt);
439 res = printk(KERN_DEBUG);
440 if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) {
441 if (in_interrupt())
442 res += printk(KERN_CONT "<intr> ");
443 else
444 res += printk(KERN_CONT "[%d] ", task_pid_vnr(current));
445 }
446 if (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME)
447 res += printk(KERN_CONT "%s:", descriptor->modname);
448 if (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
449 res += printk(KERN_CONT "%s:", descriptor->function);
450 if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
451 res += printk(KERN_CONT "%d ", descriptor->lineno);
452 res += vprintk(fmt, args);
453 va_end(args);
454
455 return res;
456}
457EXPORT_SYMBOL(__dynamic_pr_debug);
458
Thomas Renningera648ec02010-08-06 16:11:02 +0200459static __initdata char ddebug_setup_string[1024];
460static __init int ddebug_setup_query(char *str)
461{
462 if (strlen(str) >= 1024) {
463 pr_warning("ddebug boot param string too large\n");
464 return 0;
465 }
466 strcpy(ddebug_setup_string, str);
467 return 1;
468}
469
470__setup("ddebug_query=", ddebug_setup_query);
471
Jason Barone9d376f2009-02-05 11:51:38 -0500472/*
473 * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
474 * command text from userspace, parses and executes it.
475 */
476static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
477 size_t len, loff_t *offp)
478{
Jason Barone9d376f2009-02-05 11:51:38 -0500479 char tmpbuf[256];
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200480 int ret;
Jason Barone9d376f2009-02-05 11:51:38 -0500481
482 if (len == 0)
483 return 0;
484 /* we don't check *offp -- multiple writes() are allowed */
485 if (len > sizeof(tmpbuf)-1)
486 return -E2BIG;
487 if (copy_from_user(tmpbuf, ubuf, len))
488 return -EFAULT;
489 tmpbuf[len] = '\0';
490 if (verbose)
491 printk(KERN_INFO "%s: read %d bytes from userspace\n",
492 __func__, (int)len);
493
Thomas Renningerfd89cfb2010-08-06 16:11:01 +0200494 ret = ddebug_exec_query(tmpbuf);
495 if (ret)
496 return ret;
Jason Barone9d376f2009-02-05 11:51:38 -0500497
498 *offp += len;
499 return len;
500}
501
502/*
503 * Set the iterator to point to the first _ddebug object
504 * and return a pointer to that first object. Returns
505 * NULL if there are no _ddebugs at all.
506 */
507static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
508{
509 if (list_empty(&ddebug_tables)) {
510 iter->table = NULL;
511 iter->idx = 0;
512 return NULL;
513 }
514 iter->table = list_entry(ddebug_tables.next,
515 struct ddebug_table, link);
516 iter->idx = 0;
517 return &iter->table->ddebugs[iter->idx];
518}
519
520/*
521 * Advance the iterator to point to the next _ddebug
522 * object from the one the iterator currently points at,
523 * and returns a pointer to the new _ddebug. Returns
524 * NULL if the iterator has seen all the _ddebugs.
525 */
526static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
527{
528 if (iter->table == NULL)
529 return NULL;
530 if (++iter->idx == iter->table->num_ddebugs) {
531 /* iterate to next table */
532 iter->idx = 0;
533 if (list_is_last(&iter->table->link, &ddebug_tables)) {
534 iter->table = NULL;
535 return NULL;
536 }
537 iter->table = list_entry(iter->table->link.next,
538 struct ddebug_table, link);
539 }
540 return &iter->table->ddebugs[iter->idx];
541}
542
543/*
544 * Seq_ops start method. Called at the start of every
545 * read() call from userspace. Takes the ddebug_lock and
546 * seeks the seq_file's iterator to the given position.
547 */
548static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
549{
550 struct ddebug_iter *iter = m->private;
551 struct _ddebug *dp;
552 int n = *pos;
553
554 if (verbose)
555 printk(KERN_INFO "%s: called m=%p *pos=%lld\n",
556 __func__, m, (unsigned long long)*pos);
557
558 mutex_lock(&ddebug_lock);
559
560 if (!n)
561 return SEQ_START_TOKEN;
562 if (n < 0)
563 return NULL;
564 dp = ddebug_iter_first(iter);
565 while (dp != NULL && --n > 0)
566 dp = ddebug_iter_next(iter);
567 return dp;
568}
569
570/*
571 * Seq_ops next method. Called several times within a read()
572 * call from userspace, with ddebug_lock held. Walks to the
573 * next _ddebug object with a special case for the header line.
574 */
575static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
576{
577 struct ddebug_iter *iter = m->private;
578 struct _ddebug *dp;
579
580 if (verbose)
581 printk(KERN_INFO "%s: called m=%p p=%p *pos=%lld\n",
582 __func__, m, p, (unsigned long long)*pos);
583
584 if (p == SEQ_START_TOKEN)
585 dp = ddebug_iter_first(iter);
586 else
587 dp = ddebug_iter_next(iter);
588 ++*pos;
589 return dp;
590}
591
592/*
593 * Seq_ops show method. Called several times within a read()
594 * call from userspace, with ddebug_lock held. Formats the
595 * current _ddebug as a single human-readable line, with a
596 * special case for the header line.
597 */
598static int ddebug_proc_show(struct seq_file *m, void *p)
599{
600 struct ddebug_iter *iter = m->private;
601 struct _ddebug *dp = p;
602 char flagsbuf[8];
603
604 if (verbose)
605 printk(KERN_INFO "%s: called m=%p p=%p\n",
606 __func__, m, p);
607
608 if (p == SEQ_START_TOKEN) {
609 seq_puts(m,
610 "# filename:lineno [module]function flags format\n");
611 return 0;
612 }
613
614 seq_printf(m, "%s:%u [%s]%s %s \"",
615 dp->filename, dp->lineno,
616 iter->table->mod_name, dp->function,
617 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
618 seq_escape(m, dp->format, "\t\r\n\"");
619 seq_puts(m, "\"\n");
620
621 return 0;
622}
623
624/*
625 * Seq_ops stop method. Called at the end of each read()
626 * call from userspace. Drops ddebug_lock.
627 */
628static void ddebug_proc_stop(struct seq_file *m, void *p)
629{
630 if (verbose)
631 printk(KERN_INFO "%s: called m=%p p=%p\n",
632 __func__, m, p);
633 mutex_unlock(&ddebug_lock);
634}
635
636static const struct seq_operations ddebug_proc_seqops = {
637 .start = ddebug_proc_start,
638 .next = ddebug_proc_next,
639 .show = ddebug_proc_show,
640 .stop = ddebug_proc_stop
641};
642
643/*
644 * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file
645 * setup dance, and also creates an iterator to walk the _ddebugs.
646 * Note that we create a seq_file always, even for O_WRONLY files
647 * where it's not needed, as doing so simplifies the ->release method.
648 */
649static int ddebug_proc_open(struct inode *inode, struct file *file)
650{
651 struct ddebug_iter *iter;
652 int err;
653
654 if (verbose)
655 printk(KERN_INFO "%s: called\n", __func__);
656
657 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
658 if (iter == NULL)
659 return -ENOMEM;
660
661 err = seq_open(file, &ddebug_proc_seqops);
662 if (err) {
663 kfree(iter);
664 return err;
665 }
666 ((struct seq_file *) file->private_data)->private = iter;
667 return 0;
668}
669
670static const struct file_operations ddebug_proc_fops = {
671 .owner = THIS_MODULE,
672 .open = ddebug_proc_open,
673 .read = seq_read,
674 .llseek = seq_lseek,
675 .release = seq_release_private,
676 .write = ddebug_proc_write
677};
678
679/*
680 * Allocate a new ddebug_table for the given module
681 * and add it to the global list.
682 */
683int ddebug_add_module(struct _ddebug *tab, unsigned int n,
684 const char *name)
685{
686 struct ddebug_table *dt;
687 char *new_name;
688
689 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
690 if (dt == NULL)
691 return -ENOMEM;
692 new_name = kstrdup(name, GFP_KERNEL);
693 if (new_name == NULL) {
694 kfree(dt);
695 return -ENOMEM;
696 }
697 dt->mod_name = new_name;
698 dt->num_ddebugs = n;
699 dt->num_enabled = 0;
700 dt->ddebugs = tab;
701
702 mutex_lock(&ddebug_lock);
703 list_add_tail(&dt->link, &ddebug_tables);
704 mutex_unlock(&ddebug_lock);
705
706 if (verbose)
707 printk(KERN_INFO "%u debug prints in module %s\n",
708 n, dt->mod_name);
709 return 0;
710}
711EXPORT_SYMBOL_GPL(ddebug_add_module);
712
713static void ddebug_table_free(struct ddebug_table *dt)
714{
715 list_del_init(&dt->link);
716 kfree(dt->mod_name);
717 kfree(dt);
718}
719
720/*
721 * Called in response to a module being unloaded. Removes
722 * any ddebug_table's which point at the module.
723 */
Yehuda Sadehff49d742010-07-03 13:07:35 +1000724int ddebug_remove_module(const char *mod_name)
Jason Barone9d376f2009-02-05 11:51:38 -0500725{
726 struct ddebug_table *dt, *nextdt;
727 int ret = -ENOENT;
728
729 if (verbose)
730 printk(KERN_INFO "%s: removing module \"%s\"\n",
731 __func__, mod_name);
732
733 mutex_lock(&ddebug_lock);
734 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
735 if (!strcmp(dt->mod_name, mod_name)) {
736 ddebug_table_free(dt);
737 ret = 0;
738 }
739 }
740 mutex_unlock(&ddebug_lock);
741 return ret;
742}
743EXPORT_SYMBOL_GPL(ddebug_remove_module);
744
745static void ddebug_remove_all_tables(void)
746{
747 mutex_lock(&ddebug_lock);
748 while (!list_empty(&ddebug_tables)) {
749 struct ddebug_table *dt = list_entry(ddebug_tables.next,
750 struct ddebug_table,
751 link);
752 ddebug_table_free(dt);
753 }
754 mutex_unlock(&ddebug_lock);
755}
756
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200757static __initdata int ddebug_init_success;
758
759static int __init dynamic_debug_init_debugfs(void)
Jason Barone9d376f2009-02-05 11:51:38 -0500760{
761 struct dentry *dir, *file;
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200762
763 if (!ddebug_init_success)
764 return -ENODEV;
Jason Barone9d376f2009-02-05 11:51:38 -0500765
766 dir = debugfs_create_dir("dynamic_debug", NULL);
767 if (!dir)
768 return -ENOMEM;
769 file = debugfs_create_file("control", 0644, dir, NULL,
770 &ddebug_proc_fops);
771 if (!file) {
772 debugfs_remove(dir);
773 return -ENOMEM;
774 }
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200775 return 0;
776}
777
778static int __init dynamic_debug_init(void)
779{
780 struct _ddebug *iter, *iter_start;
781 const char *modname = NULL;
782 int ret = 0;
783 int n = 0;
784
Jason Barone9d376f2009-02-05 11:51:38 -0500785 if (__start___verbose != __stop___verbose) {
786 iter = __start___verbose;
787 modname = iter->modname;
788 iter_start = iter;
789 for (; iter < __stop___verbose; iter++) {
790 if (strcmp(modname, iter->modname)) {
791 ret = ddebug_add_module(iter_start, n, modname);
792 if (ret)
793 goto out_free;
794 n = 0;
795 modname = iter->modname;
796 iter_start = iter;
797 }
798 n++;
799 }
800 ret = ddebug_add_module(iter_start, n, modname);
801 }
Thomas Renningera648ec02010-08-06 16:11:02 +0200802
803 /* ddebug_query boot param got passed -> set it up */
804 if (ddebug_setup_string[0] != '\0') {
805 ret = ddebug_exec_query(ddebug_setup_string);
806 if (ret)
807 pr_warning("Invalid ddebug boot param %s",
808 ddebug_setup_string);
809 else
810 pr_info("ddebug initialized with string %s",
811 ddebug_setup_string);
Jason Barone9d376f2009-02-05 11:51:38 -0500812 }
Thomas Renningera648ec02010-08-06 16:11:02 +0200813
Jason Barone9d376f2009-02-05 11:51:38 -0500814out_free:
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200815 if (ret)
Jason Barone9d376f2009-02-05 11:51:38 -0500816 ddebug_remove_all_tables();
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200817 else
818 ddebug_init_success = 1;
Jason Barone9d376f2009-02-05 11:51:38 -0500819 return 0;
820}
Thomas Renninger6a5c0832010-08-06 16:11:03 +0200821/* Allow early initialization for boot messages via boot param */
822arch_initcall(dynamic_debug_init);
823/* Debugfs setup must be done later */
824module_init(dynamic_debug_init_debugfs);