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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. |
10 | * Copyright (C) 2011 Bart Van Assche. All Rights Reserved. |
11 | */ |
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> |
25 | #include <linux/string.h> |
26 | #include <linux/uaccess.h> |
27 | #include <linux/dynamic_debug.h> |
28 | #include <linux/debugfs.h> |
29 | #include <linux/slab.h> |
30 | #include <linux/jump_label.h> |
31 | #include <linux/hardirq.h> |
32 | #include <linux/sched.h> |
33 | |
34 | extern struct _ddebug __start___verbose[]; |
35 | extern struct _ddebug __stop___verbose[]; |
36 | |
37 | struct 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 | |
45 | struct 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 | |
53 | struct ddebug_iter { |
54 | struct ddebug_table *table; |
55 | unsigned int idx; |
56 | }; |
57 | |
58 | static DEFINE_MUTEX(ddebug_lock); |
59 | static LIST_HEAD(ddebug_tables); |
60 | static int verbose = 0; |
61 | |
62 | /* Return the last part of a pathname */ |
63 | static inline const char *basename(const char *path) |
64 | { |
65 | const char *tail = strrchr(path, '/'); |
66 | return tail ? tail+1 : path; |
67 | } |
68 | |
69 | static 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 | |
77 | /* format a string into buf[] which describes the _ddebug's flags */ |
78 | static char *ddebug_describe_flags(struct _ddebug *dp, char *buf, |
79 | size_t maxlen) |
80 | { |
81 | char *p = buf; |
82 | int i; |
83 | |
84 | BUG_ON(maxlen < 4); |
85 | for (i = 0; i < ARRAY_SIZE(opt_array); ++i) |
86 | if (dp->flags & opt_array[i].flag) |
87 | *p++ = opt_array[i].opt_char; |
88 | if (p == buf) |
89 | *p++ = '-'; |
90 | *p = '\0'; |
91 | |
92 | return buf; |
93 | } |
94 | |
95 | /* |
96 | * 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 | */ |
101 | static 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--; |
154 | else if (!dp->flags) |
155 | dt->num_enabled++; |
156 | dp->flags = newflags; |
157 | if (newflags) |
158 | dp->enabled = 1; |
159 | else |
160 | dp->enabled = 0; |
161 | 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 | /* |
177 | * Split the buffer `buf' into space-separated words. |
178 | * Handles simple " and ' quoting, i.e. without nested, |
179 | * embedded or escaped \". Return the number of words |
180 | * or <0 on error. |
181 | */ |
182 | static int ddebug_tokenize(char *buf, char *words[], int maxwords) |
183 | { |
184 | int nwords = 0; |
185 | |
186 | while (*buf) { |
187 | char *end; |
188 | |
189 | /* Skip leading whitespace */ |
190 | buf = skip_spaces(buf); |
191 | 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 | } |
215 | |
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 | */ |
232 | static 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') |
250 | static 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 | */ |
298 | static 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 | */ |
355 | static int ddebug_parse_flags(const char *str, unsigned int *flagsp, |
356 | unsigned int *maskp) |
357 | { |
358 | unsigned flags = 0; |
359 | int op = '=', i; |
360 | |
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) { |
374 | 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 | } |
379 | } |
380 | if (i < 0) |
381 | return -EINVAL; |
382 | } |
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 | |
409 | static 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 | |
430 | int __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 | } |
457 | EXPORT_SYMBOL(__dynamic_pr_debug); |
458 | |
459 | static __initdata char ddebug_setup_string[1024]; |
460 | static __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 | |
472 | /* |
473 | * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the |
474 | * command text from userspace, parses and executes it. |
475 | */ |
476 | static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, |
477 | size_t len, loff_t *offp) |
478 | { |
479 | char tmpbuf[256]; |
480 | int ret; |
481 | |
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 | |
494 | ret = ddebug_exec_query(tmpbuf); |
495 | if (ret) |
496 | return ret; |
497 | |
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 | */ |
507 | static 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 | */ |
526 | static 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 | */ |
548 | static 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 | */ |
575 | static 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 | */ |
598 | static 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 | */ |
628 | static 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 | |
636 | static 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 | */ |
649 | static 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 | |
670 | static 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 | */ |
683 | int 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 | } |
711 | EXPORT_SYMBOL_GPL(ddebug_add_module); |
712 | |
713 | static 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 | */ |
724 | int ddebug_remove_module(const char *mod_name) |
725 | { |
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 | } |
743 | EXPORT_SYMBOL_GPL(ddebug_remove_module); |
744 | |
745 | static 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 | |
757 | static __initdata int ddebug_init_success; |
758 | |
759 | static int __init dynamic_debug_init_debugfs(void) |
760 | { |
761 | struct dentry *dir, *file; |
762 | |
763 | if (!ddebug_init_success) |
764 | return -ENODEV; |
765 | |
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 | } |
775 | return 0; |
776 | } |
777 | |
778 | static 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 | |
785 | 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 | } |
802 | |
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); |
812 | } |
813 | |
814 | out_free: |
815 | if (ret) |
816 | ddebug_remove_all_tables(); |
817 | else |
818 | ddebug_init_success = 1; |
819 | return 0; |
820 | } |
821 | /* Allow early initialization for boot messages via boot param */ |
822 | arch_initcall(dynamic_debug_init); |
823 | /* Debugfs setup must be done later */ |
824 | module_init(dynamic_debug_init_debugfs); |
825 |
Branches:
ben-wpan
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javiroman/ks7010
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9