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e9d376f0
JB
1/*
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.
8ba6ebf5 10 * Copyright (C) 2011 Bart Van Assche. All Rights Reserved.
e9d376f0
JB
11 */
12
4ad275e5
JP
13#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
14
e9d376f0
JB
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/moduleparam.h>
18#include <linux/kallsyms.h>
19#include <linux/version.h>
20#include <linux/types.h>
21#include <linux/mutex.h>
22#include <linux/proc_fs.h>
23#include <linux/seq_file.h>
24#include <linux/list.h>
25#include <linux/sysctl.h>
26#include <linux/ctype.h>
e7d2860b 27#include <linux/string.h>
e9d376f0
JB
28#include <linux/uaccess.h>
29#include <linux/dynamic_debug.h>
30#include <linux/debugfs.h>
5a0e3ad6 31#include <linux/slab.h>
52159d98 32#include <linux/jump_label.h>
8ba6ebf5 33#include <linux/hardirq.h>
e8d9792a 34#include <linux/sched.h>
cbc46635 35#include <linux/device.h>
ffa10cb4 36#include <linux/netdevice.h>
e9d376f0
JB
37
38extern struct _ddebug __start___verbose[];
39extern struct _ddebug __stop___verbose[];
40
e9d376f0
JB
41struct ddebug_table {
42 struct list_head link;
43 char *mod_name;
44 unsigned int num_ddebugs;
e9d376f0
JB
45 struct _ddebug *ddebugs;
46};
47
48struct ddebug_query {
49 const char *filename;
50 const char *module;
51 const char *function;
52 const char *format;
53 unsigned int first_lineno, last_lineno;
54};
55
56struct ddebug_iter {
57 struct ddebug_table *table;
58 unsigned int idx;
59};
60
61static DEFINE_MUTEX(ddebug_lock);
62static LIST_HEAD(ddebug_tables);
63static int verbose = 0;
64
65/* Return the last part of a pathname */
66static inline const char *basename(const char *path)
67{
68 const char *tail = strrchr(path, '/');
69 return tail ? tail+1 : path;
70}
71
8ba6ebf5
BVA
72static struct { unsigned flag:8; char opt_char; } opt_array[] = {
73 { _DPRINTK_FLAGS_PRINT, 'p' },
74 { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
75 { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
76 { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
77 { _DPRINTK_FLAGS_INCL_TID, 't' },
78};
79
e9d376f0
JB
80/* format a string into buf[] which describes the _ddebug's flags */
81static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
82 size_t maxlen)
83{
84 char *p = buf;
8ba6ebf5 85 int i;
e9d376f0
JB
86
87 BUG_ON(maxlen < 4);
8ba6ebf5
BVA
88 for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
89 if (dp->flags & opt_array[i].flag)
90 *p++ = opt_array[i].opt_char;
e9d376f0
JB
91 if (p == buf)
92 *p++ = '-';
93 *p = '\0';
94
95 return buf;
96}
97
e9d376f0
JB
98/*
99 * Search the tables for _ddebug's which match the given
100 * `query' and apply the `flags' and `mask' to them. Tells
101 * the user which ddebug's were changed, or whether none
102 * were matched.
103 */
104static void ddebug_change(const struct ddebug_query *query,
105 unsigned int flags, unsigned int mask)
106{
107 int i;
108 struct ddebug_table *dt;
109 unsigned int newflags;
110 unsigned int nfound = 0;
111 char flagbuf[8];
112
113 /* search for matching ddebugs */
114 mutex_lock(&ddebug_lock);
115 list_for_each_entry(dt, &ddebug_tables, link) {
116
117 /* match against the module name */
118 if (query->module != NULL &&
119 strcmp(query->module, dt->mod_name))
120 continue;
121
122 for (i = 0 ; i < dt->num_ddebugs ; i++) {
123 struct _ddebug *dp = &dt->ddebugs[i];
124
125 /* match against the source filename */
126 if (query->filename != NULL &&
127 strcmp(query->filename, dp->filename) &&
128 strcmp(query->filename, basename(dp->filename)))
129 continue;
130
131 /* match against the function */
132 if (query->function != NULL &&
133 strcmp(query->function, dp->function))
134 continue;
135
136 /* match against the format */
137 if (query->format != NULL &&
138 strstr(dp->format, query->format) == NULL)
139 continue;
140
141 /* match against the line number range */
142 if (query->first_lineno &&
143 dp->lineno < query->first_lineno)
144 continue;
145 if (query->last_lineno &&
146 dp->lineno > query->last_lineno)
147 continue;
148
149 nfound++;
150
151 newflags = (dp->flags & mask) | flags;
152 if (newflags == dp->flags)
153 continue;
e9d376f0 154 dp->flags = newflags;
2d75af2f
JB
155 if (newflags)
156 dp->enabled = 1;
157 else
158 dp->enabled = 0;
e9d376f0 159 if (verbose)
4ad275e5 160 pr_info("changed %s:%d [%s]%s %s\n",
e9d376f0
JB
161 dp->filename, dp->lineno,
162 dt->mod_name, dp->function,
163 ddebug_describe_flags(dp, flagbuf,
164 sizeof(flagbuf)));
165 }
166 }
167 mutex_unlock(&ddebug_lock);
168
169 if (!nfound && verbose)
4ad275e5 170 pr_info("no matches for query\n");
e9d376f0
JB
171}
172
e9d376f0
JB
173/*
174 * Split the buffer `buf' into space-separated words.
9898abb3
GB
175 * Handles simple " and ' quoting, i.e. without nested,
176 * embedded or escaped \". Return the number of words
177 * or <0 on error.
e9d376f0
JB
178 */
179static int ddebug_tokenize(char *buf, char *words[], int maxwords)
180{
181 int nwords = 0;
182
9898abb3
GB
183 while (*buf) {
184 char *end;
185
186 /* Skip leading whitespace */
e7d2860b 187 buf = skip_spaces(buf);
9898abb3
GB
188 if (!*buf)
189 break; /* oh, it was trailing whitespace */
190
191 /* Run `end' over a word, either whitespace separated or quoted */
192 if (*buf == '"' || *buf == '\'') {
193 int quote = *buf++;
194 for (end = buf ; *end && *end != quote ; end++)
195 ;
196 if (!*end)
197 return -EINVAL; /* unclosed quote */
198 } else {
199 for (end = buf ; *end && !isspace(*end) ; end++)
200 ;
201 BUG_ON(end == buf);
202 }
203 /* Here `buf' is the start of the word, `end' is one past the end */
204
205 if (nwords == maxwords)
206 return -EINVAL; /* ran out of words[] before bytes */
207 if (*end)
208 *end++ = '\0'; /* terminate the word */
209 words[nwords++] = buf;
210 buf = end;
211 }
e9d376f0
JB
212
213 if (verbose) {
214 int i;
4ad275e5 215 pr_info("split into words:");
e9d376f0 216 for (i = 0 ; i < nwords ; i++)
4ad275e5
JP
217 pr_cont(" \"%s\"", words[i]);
218 pr_cont("\n");
e9d376f0
JB
219 }
220
221 return nwords;
222}
223
224/*
225 * Parse a single line number. Note that the empty string ""
226 * is treated as a special case and converted to zero, which
227 * is later treated as a "don't care" value.
228 */
229static inline int parse_lineno(const char *str, unsigned int *val)
230{
231 char *end = NULL;
232 BUG_ON(str == NULL);
233 if (*str == '\0') {
234 *val = 0;
235 return 0;
236 }
237 *val = simple_strtoul(str, &end, 10);
238 return end == NULL || end == str || *end != '\0' ? -EINVAL : 0;
239}
240
241/*
242 * Undo octal escaping in a string, inplace. This is useful to
243 * allow the user to express a query which matches a format
244 * containing embedded spaces.
245 */
246#define isodigit(c) ((c) >= '0' && (c) <= '7')
247static char *unescape(char *str)
248{
249 char *in = str;
250 char *out = str;
251
252 while (*in) {
253 if (*in == '\\') {
254 if (in[1] == '\\') {
255 *out++ = '\\';
256 in += 2;
257 continue;
258 } else if (in[1] == 't') {
259 *out++ = '\t';
260 in += 2;
261 continue;
262 } else if (in[1] == 'n') {
263 *out++ = '\n';
264 in += 2;
265 continue;
266 } else if (isodigit(in[1]) &&
267 isodigit(in[2]) &&
268 isodigit(in[3])) {
269 *out++ = ((in[1] - '0')<<6) |
270 ((in[2] - '0')<<3) |
271 (in[3] - '0');
272 in += 4;
273 continue;
274 }
275 }
276 *out++ = *in++;
277 }
278 *out = '\0';
279
280 return str;
281}
282
283/*
284 * Parse words[] as a ddebug query specification, which is a series
285 * of (keyword, value) pairs chosen from these possibilities:
286 *
287 * func <function-name>
288 * file <full-pathname>
289 * file <base-filename>
290 * module <module-name>
291 * format <escaped-string-to-find-in-format>
292 * line <lineno>
293 * line <first-lineno>-<last-lineno> // where either may be empty
294 */
295static int ddebug_parse_query(char *words[], int nwords,
296 struct ddebug_query *query)
297{
298 unsigned int i;
299
300 /* check we have an even number of words */
301 if (nwords % 2 != 0)
302 return -EINVAL;
303 memset(query, 0, sizeof(*query));
304
305 for (i = 0 ; i < nwords ; i += 2) {
306 if (!strcmp(words[i], "func"))
307 query->function = words[i+1];
308 else if (!strcmp(words[i], "file"))
309 query->filename = words[i+1];
310 else if (!strcmp(words[i], "module"))
311 query->module = words[i+1];
312 else if (!strcmp(words[i], "format"))
313 query->format = unescape(words[i+1]);
314 else if (!strcmp(words[i], "line")) {
315 char *first = words[i+1];
316 char *last = strchr(first, '-');
317 if (last)
318 *last++ = '\0';
319 if (parse_lineno(first, &query->first_lineno) < 0)
320 return -EINVAL;
321 if (last != NULL) {
322 /* range <first>-<last> */
323 if (parse_lineno(last, &query->last_lineno) < 0)
324 return -EINVAL;
325 } else {
326 query->last_lineno = query->first_lineno;
327 }
328 } else {
329 if (verbose)
4ad275e5 330 pr_err("unknown keyword \"%s\"\n", words[i]);
e9d376f0
JB
331 return -EINVAL;
332 }
333 }
334
335 if (verbose)
4ad275e5
JP
336 pr_info("q->function=\"%s\" q->filename=\"%s\" "
337 "q->module=\"%s\" q->format=\"%s\" q->lineno=%u-%u\n",
338 query->function, query->filename,
e9d376f0
JB
339 query->module, query->format, query->first_lineno,
340 query->last_lineno);
341
342 return 0;
343}
344
345/*
346 * Parse `str' as a flags specification, format [-+=][p]+.
347 * Sets up *maskp and *flagsp to be used when changing the
348 * flags fields of matched _ddebug's. Returns 0 on success
349 * or <0 on error.
350 */
351static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
352 unsigned int *maskp)
353{
354 unsigned flags = 0;
8ba6ebf5 355 int op = '=', i;
e9d376f0
JB
356
357 switch (*str) {
358 case '+':
359 case '-':
360 case '=':
361 op = *str++;
362 break;
363 default:
364 return -EINVAL;
365 }
366 if (verbose)
4ad275e5 367 pr_info("op='%c'\n", op);
e9d376f0
JB
368
369 for ( ; *str ; ++str) {
8ba6ebf5
BVA
370 for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
371 if (*str == opt_array[i].opt_char) {
372 flags |= opt_array[i].flag;
373 break;
374 }
e9d376f0 375 }
8ba6ebf5
BVA
376 if (i < 0)
377 return -EINVAL;
e9d376f0
JB
378 }
379 if (flags == 0)
380 return -EINVAL;
381 if (verbose)
4ad275e5 382 pr_info("flags=0x%x\n", flags);
e9d376f0
JB
383
384 /* calculate final *flagsp, *maskp according to mask and op */
385 switch (op) {
386 case '=':
387 *maskp = 0;
388 *flagsp = flags;
389 break;
390 case '+':
391 *maskp = ~0U;
392 *flagsp = flags;
393 break;
394 case '-':
395 *maskp = ~flags;
396 *flagsp = 0;
397 break;
398 }
399 if (verbose)
4ad275e5 400 pr_info("*flagsp=0x%x *maskp=0x%x\n", *flagsp, *maskp);
e9d376f0
JB
401 return 0;
402}
403
fd89cfb8
TR
404static int ddebug_exec_query(char *query_string)
405{
406 unsigned int flags = 0, mask = 0;
407 struct ddebug_query query;
408#define MAXWORDS 9
409 int nwords;
410 char *words[MAXWORDS];
411
412 nwords = ddebug_tokenize(query_string, words, MAXWORDS);
413 if (nwords <= 0)
414 return -EINVAL;
415 if (ddebug_parse_query(words, nwords-1, &query))
416 return -EINVAL;
417 if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
418 return -EINVAL;
419
420 /* actually go and implement the change */
421 ddebug_change(&query, flags, mask);
422 return 0;
423}
424
6c2140ee 425static int dynamic_emit_prefix(const struct _ddebug *descriptor)
8ba6ebf5 426{
5b2ebce4
JP
427 char tid[sizeof(int) + sizeof(int)/2 + 4];
428 char lineno[sizeof(int) + sizeof(int)/2];
8ba6ebf5 429
8ba6ebf5
BVA
430 if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) {
431 if (in_interrupt())
5b2ebce4 432 snprintf(tid, sizeof(tid), "%s", "<intr> ");
8ba6ebf5 433 else
5b2ebce4
JP
434 snprintf(tid, sizeof(tid), "[%d] ",
435 task_pid_vnr(current));
436 } else {
437 tid[0] = 0;
8ba6ebf5 438 }
6c2140ee 439
5b2ebce4
JP
440 if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
441 snprintf(lineno, sizeof(lineno), "%d", descriptor->lineno);
442 else
443 lineno[0] = 0;
444
445 return printk(KERN_DEBUG "%s%s%s%s%s%s",
446 tid,
447 (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME) ?
448 descriptor->modname : "",
449 (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME) ?
450 ":" : "",
451 (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) ?
452 descriptor->function : "",
453 (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME) ?
454 ":" : "",
455 lineno);
6c2140ee
JP
456}
457
458int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
459{
460 va_list args;
461 int res;
462
463 BUG_ON(!descriptor);
464 BUG_ON(!fmt);
465
466 va_start(args, fmt);
467
468 res = dynamic_emit_prefix(descriptor);
8ba6ebf5 469 res += vprintk(fmt, args);
6c2140ee 470
8ba6ebf5
BVA
471 va_end(args);
472
473 return res;
474}
475EXPORT_SYMBOL(__dynamic_pr_debug);
476
cbc46635
JP
477int __dynamic_dev_dbg(struct _ddebug *descriptor,
478 const struct device *dev, const char *fmt, ...)
479{
480 struct va_format vaf;
481 va_list args;
482 int res;
483
484 BUG_ON(!descriptor);
485 BUG_ON(!fmt);
486
487 va_start(args, fmt);
488
489 vaf.fmt = fmt;
490 vaf.va = &args;
491
6c2140ee 492 res = dynamic_emit_prefix(descriptor);
cbc46635
JP
493 res += __dev_printk(KERN_CONT, dev, &vaf);
494
495 va_end(args);
496
497 return res;
498}
499EXPORT_SYMBOL(__dynamic_dev_dbg);
500
ffa10cb4
JB
501int __dynamic_netdev_dbg(struct _ddebug *descriptor,
502 const struct net_device *dev, const char *fmt, ...)
503{
504 struct va_format vaf;
505 va_list args;
506 int res;
507
508 BUG_ON(!descriptor);
509 BUG_ON(!fmt);
510
511 va_start(args, fmt);
512
513 vaf.fmt = fmt;
514 vaf.va = &args;
515
516 res = dynamic_emit_prefix(descriptor);
517 res += __netdev_printk(KERN_CONT, dev, &vaf);
518
519 va_end(args);
520
521 return res;
522}
523EXPORT_SYMBOL(__dynamic_netdev_dbg);
524
a648ec05
TR
525static __initdata char ddebug_setup_string[1024];
526static __init int ddebug_setup_query(char *str)
527{
528 if (strlen(str) >= 1024) {
4ad275e5 529 pr_warn("ddebug boot param string too large\n");
a648ec05
TR
530 return 0;
531 }
532 strcpy(ddebug_setup_string, str);
533 return 1;
534}
535
536__setup("ddebug_query=", ddebug_setup_query);
537
e9d376f0
JB
538/*
539 * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the
540 * command text from userspace, parses and executes it.
541 */
542static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
543 size_t len, loff_t *offp)
544{
e9d376f0 545 char tmpbuf[256];
fd89cfb8 546 int ret;
e9d376f0
JB
547
548 if (len == 0)
549 return 0;
550 /* we don't check *offp -- multiple writes() are allowed */
551 if (len > sizeof(tmpbuf)-1)
552 return -E2BIG;
553 if (copy_from_user(tmpbuf, ubuf, len))
554 return -EFAULT;
555 tmpbuf[len] = '\0';
556 if (verbose)
4ad275e5 557 pr_info("read %d bytes from userspace\n", (int)len);
e9d376f0 558
fd89cfb8
TR
559 ret = ddebug_exec_query(tmpbuf);
560 if (ret)
561 return ret;
e9d376f0
JB
562
563 *offp += len;
564 return len;
565}
566
567/*
568 * Set the iterator to point to the first _ddebug object
569 * and return a pointer to that first object. Returns
570 * NULL if there are no _ddebugs at all.
571 */
572static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
573{
574 if (list_empty(&ddebug_tables)) {
575 iter->table = NULL;
576 iter->idx = 0;
577 return NULL;
578 }
579 iter->table = list_entry(ddebug_tables.next,
580 struct ddebug_table, link);
581 iter->idx = 0;
582 return &iter->table->ddebugs[iter->idx];
583}
584
585/*
586 * Advance the iterator to point to the next _ddebug
587 * object from the one the iterator currently points at,
588 * and returns a pointer to the new _ddebug. Returns
589 * NULL if the iterator has seen all the _ddebugs.
590 */
591static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
592{
593 if (iter->table == NULL)
594 return NULL;
595 if (++iter->idx == iter->table->num_ddebugs) {
596 /* iterate to next table */
597 iter->idx = 0;
598 if (list_is_last(&iter->table->link, &ddebug_tables)) {
599 iter->table = NULL;
600 return NULL;
601 }
602 iter->table = list_entry(iter->table->link.next,
603 struct ddebug_table, link);
604 }
605 return &iter->table->ddebugs[iter->idx];
606}
607
608/*
609 * Seq_ops start method. Called at the start of every
610 * read() call from userspace. Takes the ddebug_lock and
611 * seeks the seq_file's iterator to the given position.
612 */
613static void *ddebug_proc_start(struct seq_file *m, loff_t *pos)
614{
615 struct ddebug_iter *iter = m->private;
616 struct _ddebug *dp;
617 int n = *pos;
618
619 if (verbose)
4ad275e5 620 pr_info("called m=%p *pos=%lld\n", m, (unsigned long long)*pos);
e9d376f0
JB
621
622 mutex_lock(&ddebug_lock);
623
624 if (!n)
625 return SEQ_START_TOKEN;
626 if (n < 0)
627 return NULL;
628 dp = ddebug_iter_first(iter);
629 while (dp != NULL && --n > 0)
630 dp = ddebug_iter_next(iter);
631 return dp;
632}
633
634/*
635 * Seq_ops next method. Called several times within a read()
636 * call from userspace, with ddebug_lock held. Walks to the
637 * next _ddebug object with a special case for the header line.
638 */
639static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
640{
641 struct ddebug_iter *iter = m->private;
642 struct _ddebug *dp;
643
644 if (verbose)
4ad275e5
JP
645 pr_info("called m=%p p=%p *pos=%lld\n",
646 m, p, (unsigned long long)*pos);
e9d376f0
JB
647
648 if (p == SEQ_START_TOKEN)
649 dp = ddebug_iter_first(iter);
650 else
651 dp = ddebug_iter_next(iter);
652 ++*pos;
653 return dp;
654}
655
656/*
657 * Seq_ops show method. Called several times within a read()
658 * call from userspace, with ddebug_lock held. Formats the
659 * current _ddebug as a single human-readable line, with a
660 * special case for the header line.
661 */
662static int ddebug_proc_show(struct seq_file *m, void *p)
663{
664 struct ddebug_iter *iter = m->private;
665 struct _ddebug *dp = p;
666 char flagsbuf[8];
667
668 if (verbose)
4ad275e5 669 pr_info("called m=%p p=%p\n", m, p);
e9d376f0
JB
670
671 if (p == SEQ_START_TOKEN) {
672 seq_puts(m,
673 "# filename:lineno [module]function flags format\n");
674 return 0;
675 }
676
677 seq_printf(m, "%s:%u [%s]%s %s \"",
678 dp->filename, dp->lineno,
679 iter->table->mod_name, dp->function,
680 ddebug_describe_flags(dp, flagsbuf, sizeof(flagsbuf)));
681 seq_escape(m, dp->format, "\t\r\n\"");
682 seq_puts(m, "\"\n");
683
684 return 0;
685}
686
687/*
688 * Seq_ops stop method. Called at the end of each read()
689 * call from userspace. Drops ddebug_lock.
690 */
691static void ddebug_proc_stop(struct seq_file *m, void *p)
692{
693 if (verbose)
4ad275e5 694 pr_info("called m=%p p=%p\n", m, p);
e9d376f0
JB
695 mutex_unlock(&ddebug_lock);
696}
697
698static const struct seq_operations ddebug_proc_seqops = {
699 .start = ddebug_proc_start,
700 .next = ddebug_proc_next,
701 .show = ddebug_proc_show,
702 .stop = ddebug_proc_stop
703};
704
705/*
706 * File_ops->open method for <debugfs>/dynamic_debug/control. Does the seq_file
707 * setup dance, and also creates an iterator to walk the _ddebugs.
708 * Note that we create a seq_file always, even for O_WRONLY files
709 * where it's not needed, as doing so simplifies the ->release method.
710 */
711static int ddebug_proc_open(struct inode *inode, struct file *file)
712{
713 struct ddebug_iter *iter;
714 int err;
715
716 if (verbose)
4ad275e5 717 pr_info("called\n");
e9d376f0
JB
718
719 iter = kzalloc(sizeof(*iter), GFP_KERNEL);
720 if (iter == NULL)
721 return -ENOMEM;
722
723 err = seq_open(file, &ddebug_proc_seqops);
724 if (err) {
725 kfree(iter);
726 return err;
727 }
728 ((struct seq_file *) file->private_data)->private = iter;
729 return 0;
730}
731
732static const struct file_operations ddebug_proc_fops = {
733 .owner = THIS_MODULE,
734 .open = ddebug_proc_open,
735 .read = seq_read,
736 .llseek = seq_lseek,
737 .release = seq_release_private,
738 .write = ddebug_proc_write
739};
740
741/*
742 * Allocate a new ddebug_table for the given module
743 * and add it to the global list.
744 */
745int ddebug_add_module(struct _ddebug *tab, unsigned int n,
746 const char *name)
747{
748 struct ddebug_table *dt;
749 char *new_name;
750
751 dt = kzalloc(sizeof(*dt), GFP_KERNEL);
752 if (dt == NULL)
753 return -ENOMEM;
754 new_name = kstrdup(name, GFP_KERNEL);
755 if (new_name == NULL) {
756 kfree(dt);
757 return -ENOMEM;
758 }
759 dt->mod_name = new_name;
760 dt->num_ddebugs = n;
e9d376f0
JB
761 dt->ddebugs = tab;
762
763 mutex_lock(&ddebug_lock);
764 list_add_tail(&dt->link, &ddebug_tables);
765 mutex_unlock(&ddebug_lock);
766
767 if (verbose)
4ad275e5 768 pr_info("%u debug prints in module %s\n", n, dt->mod_name);
e9d376f0
JB
769 return 0;
770}
771EXPORT_SYMBOL_GPL(ddebug_add_module);
772
773static void ddebug_table_free(struct ddebug_table *dt)
774{
775 list_del_init(&dt->link);
776 kfree(dt->mod_name);
777 kfree(dt);
778}
779
780/*
781 * Called in response to a module being unloaded. Removes
782 * any ddebug_table's which point at the module.
783 */
ff49d74a 784int ddebug_remove_module(const char *mod_name)
e9d376f0
JB
785{
786 struct ddebug_table *dt, *nextdt;
787 int ret = -ENOENT;
788
789 if (verbose)
4ad275e5 790 pr_info("removing module \"%s\"\n", mod_name);
e9d376f0
JB
791
792 mutex_lock(&ddebug_lock);
793 list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) {
794 if (!strcmp(dt->mod_name, mod_name)) {
795 ddebug_table_free(dt);
796 ret = 0;
797 }
798 }
799 mutex_unlock(&ddebug_lock);
800 return ret;
801}
802EXPORT_SYMBOL_GPL(ddebug_remove_module);
803
804static void ddebug_remove_all_tables(void)
805{
806 mutex_lock(&ddebug_lock);
807 while (!list_empty(&ddebug_tables)) {
808 struct ddebug_table *dt = list_entry(ddebug_tables.next,
809 struct ddebug_table,
810 link);
811 ddebug_table_free(dt);
812 }
813 mutex_unlock(&ddebug_lock);
814}
815
6a5c083d
TR
816static __initdata int ddebug_init_success;
817
818static int __init dynamic_debug_init_debugfs(void)
e9d376f0
JB
819{
820 struct dentry *dir, *file;
6a5c083d
TR
821
822 if (!ddebug_init_success)
823 return -ENODEV;
e9d376f0
JB
824
825 dir = debugfs_create_dir("dynamic_debug", NULL);
826 if (!dir)
827 return -ENOMEM;
828 file = debugfs_create_file("control", 0644, dir, NULL,
829 &ddebug_proc_fops);
830 if (!file) {
831 debugfs_remove(dir);
832 return -ENOMEM;
833 }
6a5c083d
TR
834 return 0;
835}
836
837static int __init dynamic_debug_init(void)
838{
839 struct _ddebug *iter, *iter_start;
840 const char *modname = NULL;
841 int ret = 0;
842 int n = 0;
843
e9d376f0
JB
844 if (__start___verbose != __stop___verbose) {
845 iter = __start___verbose;
846 modname = iter->modname;
847 iter_start = iter;
848 for (; iter < __stop___verbose; iter++) {
849 if (strcmp(modname, iter->modname)) {
850 ret = ddebug_add_module(iter_start, n, modname);
851 if (ret)
852 goto out_free;
853 n = 0;
854 modname = iter->modname;
855 iter_start = iter;
856 }
857 n++;
858 }
859 ret = ddebug_add_module(iter_start, n, modname);
860 }
a648ec05
TR
861
862 /* ddebug_query boot param got passed -> set it up */
863 if (ddebug_setup_string[0] != '\0') {
864 ret = ddebug_exec_query(ddebug_setup_string);
865 if (ret)
4ad275e5
JP
866 pr_warn("Invalid ddebug boot param %s",
867 ddebug_setup_string);
a648ec05
TR
868 else
869 pr_info("ddebug initialized with string %s",
870 ddebug_setup_string);
871 }
872
e9d376f0 873out_free:
6a5c083d 874 if (ret)
e9d376f0 875 ddebug_remove_all_tables();
6a5c083d
TR
876 else
877 ddebug_init_success = 1;
e9d376f0
JB
878 return 0;
879}
6a5c083d
TR
880/* Allow early initialization for boot messages via boot param */
881arch_initcall(dynamic_debug_init);
882/* Debugfs setup must be done later */
883module_init(dynamic_debug_init_debugfs);